Organic acids are spontaneously generated in significant concentrations during natural ageing of all cellulose-based papers, the alkaline ones included. The present study reviews the paper degradation research devoted to the identification and determination of the role of light products formed during paper ageing. Accelerated ageing was performed at 98 °C and 50% RH, for 60 days. The main objective of the present study was to investigate the influence of the Mg cations included in the alkaline reserve on the progress of degradation during accelerated ageing of paper. The changes in the ratio of acetic/formic acids and the role of Mg2+ ions during accelerated ageing – in the investigated unmodified and modified papers – with dispersion of MgO or MgO and MMMC (methyl methoxy magnesium carbonate) mixture are discussed. The obtained results show that, during accelerated ageing, acetic and formic acids are produced in both unmodified and modified papers. The higher content of Mg2+ ions in modified paper increases the formation of acetic and formic acids more than in unmodified paper. The reason for this behaviour might be the strong promoting role played by the Mg2+ ions in the formation of the mentioned organic acids
Kinetic dependences for the decrease of polymerization of paper undergoing ac...Michal Jablonsky
Degradation of cellulose is an important factor influencing its physical, mechanical, optical and chemical properties and the lifetime of paper in libraries and archival holdings. Groundwood paper made around the middle of the 19th century is endangered. Documents in poor condition need treatment to prolong their lifespan for the use of future generations. To investigate the ageing stability, model groundwood newsprint paper was used. A study of the accelerated ageing of newsprint paper was performed at 98 °C during 0, 1, 2, 3, 5 ,7, 10, 15, 20 and 30 days. The efficacy of treatment using MgO in perfluoralkanes or a mixture dispersion of MgO in perfluoralkanes and methyl methoxy magnesium carbonate in methanol (ratio 3:1) was investigated. This paper aims at finding kinetic dependences for the degree of polymerization (further DP) decrease and time stability of pH value of paper undergoing accelerated ageing. The highest rate of degradation (kDP = 0.0105 ± 0.0023 h-1) was determined for the unmodified control sample. In the case of the treated samples, the rate constants of DP degradation were lower (kDP = 0.0073 ± 0.0010 h-1 and kDP = 0.0053 ±0.0009 h-1) for samples treated by MgO and MgO+MMMC, respectively.
ACCELERATED AGEING OF WOOD-CONTAINING PAPERS: FORMATION OF WEAK ACIDS AND DET...Michal Jablonsky
Deterioration process is generally the result of a series of reactions which lead to degradation of materials. Destruction of such materials is accelerated by the formation of weak acids from components used in paper production, such as mostly formic and acetic acid. These acids increase degradation of paper and at the same time they decrease mechanical properties. There is lack of detailed information on formation of acetic and formic acids in the process of accelerated ageing in connection with the loss of fibre strength in the available literature. This contribution presents information on the kinetics of acetic and formic acid formation during accelerated ageing determined by modified ASTM D 6819-02 procedure. The newsprint paper was aged from 0 to 60 days of accelerated ageing at temperature 98 °C and 50% RH in sealed 3 ply bags. The ratio of acetic acid to formic acid concentration in situ increases during the accelerated ageing is 2 times CH3COOH/HCOOH after 10 days and 5.5 times after 60 days. The loss of fibre strength due to degradation correlates well with the increase of the acetic acid concentration in situ and with the rising CH3COOH/HCOOH ratio as well.
The document summarizes a study on the biodegradation of the synthetic polymer Nylon 6 by the bacterium Pseudomonas aeruginosa NCIM. The study found that Pseudomonas aeruginosa was most effective at degrading Nylon 6 sheets compared to the fungus Trametes versicolor, as measured by greater weight loss and decreased thickness of the Nylon sheets over time. FTIR spectroscopy indicated that Pseudomonas aeruginosa mediated degradation resulted in the formation of new functional groups on the Nylon polymer chains. Therefore, the study demonstrated that Pseudomonas aeruginosa has strong potential for degrading recalcitrant polymers like Nylon 6 through biodegradation.
Polydopamine Formation In Poly (Vinyl Alcohol) + Montmorillonite Blends Allow...IJRESJOURNAL
Abstract: It is demonstrated herein that the spontaneous oxidation of dopamine by dissolved oxygen (at pH = 9.6) in blends of poly(vinyl alcohol) and montmorillonite clay allows to produce robust stable and flexible sheets of material upon solvent casting and drying. The size of the membrane is only limited by the surface area of the collector vessel. In the absence of dopamine, and hence polydopamine, the deposit obtained in the same conditions undergoes cracks and does not form a material with the desired shape. Some structural characterizations of the PDA@PVA-MMT membranes and of the PVA-MMT blends are undertaken
Delignification of pulp with two ternary deep eutectic solvents: Urea-acetami...Michal Jablonsky
Using deep eutectic solvents (DESs), which ones act as solvent systems, offer an interesting green alternative to conventional technology in materials science, especially in the biomass processing. There is lack of information dealing with the delignification and bleaching effect of DESs in broad-leaved fiber process. This work describes application of various DESs on unbleached pulp, to study the influence of dissolution of lignin and protection of cellulose in the delignification process. In this work, two ternary deep eutectic solvents (urea-acetamide-glycerol) in molar ratio 1 : 2 : 3 and (malic acid-proline-lactic acid) in molar ratio 1 : 2 : 4 were synthesized and their density was studied in a temperature range of 25 to 75 0 C. Unbleached pulp (Kappa 14) was treated with prepared ternary deep eutectic solvents. The treatment was carried out in a water bath at present temperature of 60 0 C and atmospheric pressure for 2 hours. Solubility tests of cellulose were performed using pure cellulose (Whatman paper) in the DESs reagents. In 50 mL glass bottles, 0.5 g of the respective component was added separately into 20 mL of DES reagent and then incubated at 60 0 C for 2 h. The samples were filtered through glass fiber filters and dried at 105 0 C to constant weight. The weight of dried residual solid components was calculated in order to evaluate the % solubility in the DES reagent. Density of urea-acetamide-glycerol (molar ratio 1 : 2 : 3) decreased with a temperature from 1,220 to 1,199 g/cm 3 and density of malic acid-proline-lactic acid (molar ratio 1 : 2 : 4) decreased from 1,292 to 1,220 g/cm 3. Application of DESs to the lignocellulosic matrix pulp does not resulted in a significant decrease of lignin content. Deep eutectic solvent (urea-acet-amide-glycerol) in molar ratio 1 : 2 : 3 removed 5,4 % and DES (malic acid-proline-lactic acid) in molar ratio 1 : 2 : 4 removed 1.4 % lignin from unbleached pulp. The solubility of cellulose in ternary deep eutectic solvents was zero. Results show that prepared ternary deep eutectic solvents are able to delignify the pulp. However, the efficiency of delignification is not comparable to that of oxygen delignification. At the same time, used deep eutectic solvents do not cause dissolution of cellulose in pulp fibers.
Potential Biodeteriogens of Indoor and Outdoor Surfaces (Coated With Gloss, E...IOSR Journals
Potential Biodeteriogens of indoor and outdoor surfaces (coated with gloss, emulsion and text coat paints) within the University of Port Harcourt, Nigeria were investigated. Potential Biodeteriogens implicated in deterioration of painted surfaces were bacteria, fungi, microalgae and cyanobacteria. The total heterotrophic bacteria counts and total fungal counts for outdoor and indoor painted surfaces ranged from 2.8 x 106 to 9.00 x 106 cfu/g paint scrape, 1.56 x 104 to 6.6 x 104 cfu/g paint scrape; and 1.1 x 106 to 6.5 x 106 cfu/g paint scrapes, 1.31 x 104 to 9.8 x 104 cfu/g paint scrapes respectively. The result of THB and TF count expressed graphically showed surfaces with increasing order of microbial load: Gloss paints < Text coat paint < Emulsion paints. Predominant bacterial genera isolated from the surfaces include Bacillus (29.0%), Pseudomonas (22.6%), Proteus (19.4%), Serratia (16.1%), Citrobacter (6.5%), Enterobacter (3.2%) and Klebsiella (3.2%). Fungal genera isolated include: Alternaria, Aspergillus , Cladosporium , Fusarium ,Geotrichum , Gleosporium , Penicillum , Rhizopus , Saccharomyces and Stachybotrys . Fungi were the predominant biodeteriogens. Predominant microalgae isolated from the wet painted surfaces include Chorella , Characium , Closterium , Geminella , Oscillatoria , Totrogonnidium and Triceratium . Physicochemistry of various paint surfaces revealed the following: TOC (1.30 – 3.49%), Phosphate (0.39-8.82mg/100g), nitrate (4.64-187.58mg/100g), sulphate (99.78-285.00mg/100g), pH (8.55-9.59), oil and Grease (125.00-285.00mg/100g).Result showed that different consortia of biodeteriogens implicated in indoor and outdoor painted surfaces are dependent on the chemical compositions of the various paints, nature of the coating surfaces and physicochemical parameters influencing the microbial processes. Emulsion surfaces habour most potential biodeteriogens on their surfaces than the other surfaces. There were significant differences (P < 0.05) in the various potential biodeteriogens, categories of painted surfaces, indoor and outdoor surfaces.
Plastic Film from Dioscorea Hispida Dennst KOROT Tuberijtsrd
This study was conducted to produce a biodegradable plastic film from the Dioscorea Hispida Dennst korot tuber extract. Specifically, it aimed to determine the physical properties of prepared plastic film from korot extract in terms of effect of strong acid and base, flammability, pH, transparency, tensile strength and texture. It also aimed to determine the mechanical properties of prepared plastic film from “korot†extract and determine the permeability in water of the plastic film. The test for effect on strong acid and base in the two formulations showed that the plastic films were both soluble in strong acid and base. The film was flammable with luminous flame, with pH of 6.3. The produced film was smooth and transparent. The tensile strength test for formulation B was more stretchable and stronger than formulation A, and the weight resistance of formulation B was 1.2 kg while 0.8 kg for formulation A which is comparable to commercial plastic film. The two formulations differ in texture for which the formulation A was smooth and thinner than formulation B which was slightly rough. The produced plastic film was permeable in water. The prepared film was incomparable to commercial plastic wrap, for the prepared film water lost was 4.0 mL to 6.0 mL higher than 1.4 mL for commercial plastic film. The researcher found out that “korot†tuber can be used as main raw material in preparing commercial plastic and the formulation A is better than formulation B. Franz Joy A. Caballa | Melinda C. Getalado ""Plastic Film from Dioscorea Hispida Dennst (KOROT) Tuber"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019, URL: https://www.ijtsrd.com/papers/ijtsrd22936.pdf
Paper URL: https://www.ijtsrd.com/other-scientific-research-area/other/22936/plastic-film-from-dioscorea-hispida-dennst-korot-tuber/franz-joy-a-caballa
A comparison of cardanol and its derivatives as reactiveAlexander Decker
This document discusses the use of cardanol, cardanol acetate, and cardanyl methyl ether as reactive diluents in alkyd coatings to reduce volatile organic compounds (VOCs). The compounds were characterized and evaluated as partial replacements for solvent in long oil alkyd coatings. Coatings with the reactive diluents showed lower VOC levels (up to 39% reduction), faster drying times, and better properties compared to conventional coatings. Using these cardanol derivatives from cashew nut shell liquid provides advantages over petroleum-based solvents as it is renewable and reduces pollution from burning cashew nut shells.
Kinetic dependences for the decrease of polymerization of paper undergoing ac...Michal Jablonsky
Degradation of cellulose is an important factor influencing its physical, mechanical, optical and chemical properties and the lifetime of paper in libraries and archival holdings. Groundwood paper made around the middle of the 19th century is endangered. Documents in poor condition need treatment to prolong their lifespan for the use of future generations. To investigate the ageing stability, model groundwood newsprint paper was used. A study of the accelerated ageing of newsprint paper was performed at 98 °C during 0, 1, 2, 3, 5 ,7, 10, 15, 20 and 30 days. The efficacy of treatment using MgO in perfluoralkanes or a mixture dispersion of MgO in perfluoralkanes and methyl methoxy magnesium carbonate in methanol (ratio 3:1) was investigated. This paper aims at finding kinetic dependences for the degree of polymerization (further DP) decrease and time stability of pH value of paper undergoing accelerated ageing. The highest rate of degradation (kDP = 0.0105 ± 0.0023 h-1) was determined for the unmodified control sample. In the case of the treated samples, the rate constants of DP degradation were lower (kDP = 0.0073 ± 0.0010 h-1 and kDP = 0.0053 ±0.0009 h-1) for samples treated by MgO and MgO+MMMC, respectively.
ACCELERATED AGEING OF WOOD-CONTAINING PAPERS: FORMATION OF WEAK ACIDS AND DET...Michal Jablonsky
Deterioration process is generally the result of a series of reactions which lead to degradation of materials. Destruction of such materials is accelerated by the formation of weak acids from components used in paper production, such as mostly formic and acetic acid. These acids increase degradation of paper and at the same time they decrease mechanical properties. There is lack of detailed information on formation of acetic and formic acids in the process of accelerated ageing in connection with the loss of fibre strength in the available literature. This contribution presents information on the kinetics of acetic and formic acid formation during accelerated ageing determined by modified ASTM D 6819-02 procedure. The newsprint paper was aged from 0 to 60 days of accelerated ageing at temperature 98 °C and 50% RH in sealed 3 ply bags. The ratio of acetic acid to formic acid concentration in situ increases during the accelerated ageing is 2 times CH3COOH/HCOOH after 10 days and 5.5 times after 60 days. The loss of fibre strength due to degradation correlates well with the increase of the acetic acid concentration in situ and with the rising CH3COOH/HCOOH ratio as well.
The document summarizes a study on the biodegradation of the synthetic polymer Nylon 6 by the bacterium Pseudomonas aeruginosa NCIM. The study found that Pseudomonas aeruginosa was most effective at degrading Nylon 6 sheets compared to the fungus Trametes versicolor, as measured by greater weight loss and decreased thickness of the Nylon sheets over time. FTIR spectroscopy indicated that Pseudomonas aeruginosa mediated degradation resulted in the formation of new functional groups on the Nylon polymer chains. Therefore, the study demonstrated that Pseudomonas aeruginosa has strong potential for degrading recalcitrant polymers like Nylon 6 through biodegradation.
Polydopamine Formation In Poly (Vinyl Alcohol) + Montmorillonite Blends Allow...IJRESJOURNAL
Abstract: It is demonstrated herein that the spontaneous oxidation of dopamine by dissolved oxygen (at pH = 9.6) in blends of poly(vinyl alcohol) and montmorillonite clay allows to produce robust stable and flexible sheets of material upon solvent casting and drying. The size of the membrane is only limited by the surface area of the collector vessel. In the absence of dopamine, and hence polydopamine, the deposit obtained in the same conditions undergoes cracks and does not form a material with the desired shape. Some structural characterizations of the PDA@PVA-MMT membranes and of the PVA-MMT blends are undertaken
Delignification of pulp with two ternary deep eutectic solvents: Urea-acetami...Michal Jablonsky
Using deep eutectic solvents (DESs), which ones act as solvent systems, offer an interesting green alternative to conventional technology in materials science, especially in the biomass processing. There is lack of information dealing with the delignification and bleaching effect of DESs in broad-leaved fiber process. This work describes application of various DESs on unbleached pulp, to study the influence of dissolution of lignin and protection of cellulose in the delignification process. In this work, two ternary deep eutectic solvents (urea-acetamide-glycerol) in molar ratio 1 : 2 : 3 and (malic acid-proline-lactic acid) in molar ratio 1 : 2 : 4 were synthesized and their density was studied in a temperature range of 25 to 75 0 C. Unbleached pulp (Kappa 14) was treated with prepared ternary deep eutectic solvents. The treatment was carried out in a water bath at present temperature of 60 0 C and atmospheric pressure for 2 hours. Solubility tests of cellulose were performed using pure cellulose (Whatman paper) in the DESs reagents. In 50 mL glass bottles, 0.5 g of the respective component was added separately into 20 mL of DES reagent and then incubated at 60 0 C for 2 h. The samples were filtered through glass fiber filters and dried at 105 0 C to constant weight. The weight of dried residual solid components was calculated in order to evaluate the % solubility in the DES reagent. Density of urea-acetamide-glycerol (molar ratio 1 : 2 : 3) decreased with a temperature from 1,220 to 1,199 g/cm 3 and density of malic acid-proline-lactic acid (molar ratio 1 : 2 : 4) decreased from 1,292 to 1,220 g/cm 3. Application of DESs to the lignocellulosic matrix pulp does not resulted in a significant decrease of lignin content. Deep eutectic solvent (urea-acet-amide-glycerol) in molar ratio 1 : 2 : 3 removed 5,4 % and DES (malic acid-proline-lactic acid) in molar ratio 1 : 2 : 4 removed 1.4 % lignin from unbleached pulp. The solubility of cellulose in ternary deep eutectic solvents was zero. Results show that prepared ternary deep eutectic solvents are able to delignify the pulp. However, the efficiency of delignification is not comparable to that of oxygen delignification. At the same time, used deep eutectic solvents do not cause dissolution of cellulose in pulp fibers.
Potential Biodeteriogens of Indoor and Outdoor Surfaces (Coated With Gloss, E...IOSR Journals
Potential Biodeteriogens of indoor and outdoor surfaces (coated with gloss, emulsion and text coat paints) within the University of Port Harcourt, Nigeria were investigated. Potential Biodeteriogens implicated in deterioration of painted surfaces were bacteria, fungi, microalgae and cyanobacteria. The total heterotrophic bacteria counts and total fungal counts for outdoor and indoor painted surfaces ranged from 2.8 x 106 to 9.00 x 106 cfu/g paint scrape, 1.56 x 104 to 6.6 x 104 cfu/g paint scrape; and 1.1 x 106 to 6.5 x 106 cfu/g paint scrapes, 1.31 x 104 to 9.8 x 104 cfu/g paint scrapes respectively. The result of THB and TF count expressed graphically showed surfaces with increasing order of microbial load: Gloss paints < Text coat paint < Emulsion paints. Predominant bacterial genera isolated from the surfaces include Bacillus (29.0%), Pseudomonas (22.6%), Proteus (19.4%), Serratia (16.1%), Citrobacter (6.5%), Enterobacter (3.2%) and Klebsiella (3.2%). Fungal genera isolated include: Alternaria, Aspergillus , Cladosporium , Fusarium ,Geotrichum , Gleosporium , Penicillum , Rhizopus , Saccharomyces and Stachybotrys . Fungi were the predominant biodeteriogens. Predominant microalgae isolated from the wet painted surfaces include Chorella , Characium , Closterium , Geminella , Oscillatoria , Totrogonnidium and Triceratium . Physicochemistry of various paint surfaces revealed the following: TOC (1.30 – 3.49%), Phosphate (0.39-8.82mg/100g), nitrate (4.64-187.58mg/100g), sulphate (99.78-285.00mg/100g), pH (8.55-9.59), oil and Grease (125.00-285.00mg/100g).Result showed that different consortia of biodeteriogens implicated in indoor and outdoor painted surfaces are dependent on the chemical compositions of the various paints, nature of the coating surfaces and physicochemical parameters influencing the microbial processes. Emulsion surfaces habour most potential biodeteriogens on their surfaces than the other surfaces. There were significant differences (P < 0.05) in the various potential biodeteriogens, categories of painted surfaces, indoor and outdoor surfaces.
Plastic Film from Dioscorea Hispida Dennst KOROT Tuberijtsrd
This study was conducted to produce a biodegradable plastic film from the Dioscorea Hispida Dennst korot tuber extract. Specifically, it aimed to determine the physical properties of prepared plastic film from korot extract in terms of effect of strong acid and base, flammability, pH, transparency, tensile strength and texture. It also aimed to determine the mechanical properties of prepared plastic film from “korot†extract and determine the permeability in water of the plastic film. The test for effect on strong acid and base in the two formulations showed that the plastic films were both soluble in strong acid and base. The film was flammable with luminous flame, with pH of 6.3. The produced film was smooth and transparent. The tensile strength test for formulation B was more stretchable and stronger than formulation A, and the weight resistance of formulation B was 1.2 kg while 0.8 kg for formulation A which is comparable to commercial plastic film. The two formulations differ in texture for which the formulation A was smooth and thinner than formulation B which was slightly rough. The produced plastic film was permeable in water. The prepared film was incomparable to commercial plastic wrap, for the prepared film water lost was 4.0 mL to 6.0 mL higher than 1.4 mL for commercial plastic film. The researcher found out that “korot†tuber can be used as main raw material in preparing commercial plastic and the formulation A is better than formulation B. Franz Joy A. Caballa | Melinda C. Getalado ""Plastic Film from Dioscorea Hispida Dennst (KOROT) Tuber"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019, URL: https://www.ijtsrd.com/papers/ijtsrd22936.pdf
Paper URL: https://www.ijtsrd.com/other-scientific-research-area/other/22936/plastic-film-from-dioscorea-hispida-dennst-korot-tuber/franz-joy-a-caballa
A comparison of cardanol and its derivatives as reactiveAlexander Decker
This document discusses the use of cardanol, cardanol acetate, and cardanyl methyl ether as reactive diluents in alkyd coatings to reduce volatile organic compounds (VOCs). The compounds were characterized and evaluated as partial replacements for solvent in long oil alkyd coatings. Coatings with the reactive diluents showed lower VOC levels (up to 39% reduction), faster drying times, and better properties compared to conventional coatings. Using these cardanol derivatives from cashew nut shell liquid provides advantages over petroleum-based solvents as it is renewable and reduces pollution from burning cashew nut shells.
This document summarizes a study that assessed the effects of adding different non-wood materials as additives to papermaking pulp. Materials tested included apple pulp, beer fines, beetroot pieces, citrus pulp, Betacal, deinking sludge, onion skins and sawdust. The study found that most additives improved pulp dewatering properties, with sawdust, Betacal and deinking sludge showing the most positive effects. Properties like ash content and initial dryness correlated with improved dewatering. However, the effects varied between virgin and recovered pulps. Overall, the additives showed potential to enhance pulp and paper properties but further investigation is needed.
This research article investigates total chlorine-free bleaching of poplar kraft pulp using Oxone. The pulp samples underwent a two-stage Oxone bleaching sequence after an acid pretreatment stage. Various reaction parameters were optimized in each stage. The final achieved brightness was more than 78% and accelerated aging experiments showed greater brightness stability for the Oxone treated pulp. The results demonstrate the feasibility and environmental benefits of Oxone for total chlorine-free bleaching compared to other bleaching methods.
Biological Removal of Malachite Green and Congo red by Some Filamentous FungiIJEAB
Four strains of filamentous fungi were studied to a removal of Malachite green (MG) and Congo red (CR). These fungi were Aspergillus niger ,Aspergillus flavus , Aspergillus versicolor and P. funigulosum. P. funigulosum showed that decolorization activity was higher than other fungi on solid medium containing MG and CR . The stastical method obtained that there was no significance between fungi . All these fungi were able to degradation dyes to other metabolites . The dry weight ( Biomass) of P. funigulosum reached to 1.10 ,1.02 in mineral salts medium (MSM) with MG and CR respectively , and the stastical methods obtained that there was no significance in dry weights between fungi .
4. optimization of culture condition for enhanced decolorization of reactive ...Darshan Rudakiya
Many synthetic azo dyes and their metabolites are toxic, carcinogenic, and
mutagenic so removal of azo dyes using cost-effective and eco-friendly method is
major aspect.Comamonas acidovorans MTCC 3364 has been routinely reported for
different steroid bioconversion and heavy metal removal. The main purpose of this
study is to check the decolorization efficiency of Comamonas acidovorans MTCC
3364 for different dyes and to optimize the condition which gives maximum
decolorization of Reactive Orange 16 dye. The effect of various physicochemical
parameters including condition, carbon and nitrogen sources, temperature,pH and
dye concentration were studied. The % decolorization of dye was determined by
UV Visible spectroscopy. This bacterial strain efficiently decolorizes Reactive
Orange 16 at 37oC, pH 6.85 within 24 hours giving 99.03 ± 0.5 % dye
decolorization under optimum environmental conditions.
Doped Titania Project Zinc Focus - George J. Ferko VGeorge Ferko
This document summarizes a study on the sintering behavior of titania doped with zinc, copper, and boron at concentrations of 1% and 10%. Titania has many industrial applications as a white pigment. The study examines how the dopants, doping levels, sintering temperature, and sintering time affect the densification and grain growth of the doped titania samples during conventional sintering. Samples were prepared through a multi-step process including mixing, calcining, pressing, and sintering. Microstructural analysis using SEM revealed that copper doped samples contained a second phase, zinc doped samples contained a second phase at higher temperatures, and boron doped samples exhibited abnormal
A Selective Study on Decolorization of Textile Azo Dye using Genetically Modi...BRNSS Publication Hub
This document summarizes research on using genetically modified brown-rot fungi to decolorize textile dyes. Brown-rot fungi naturally produce enzymes that can break down lignin and other complex molecules. The researchers genetically modified brown-rot fungi to enhance their ability to decolorize textile dyes. They tested the modified fungi on textile effluents and various dyes. The genetically modified brown-rot fungi showed improved ability to decolorize textile dyes compared to unmodified fungi. The document also describes techniques used to modify the fungi and evaluate their dye decolorization abilities.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
The bleaching chemistry indicates that pH affects the effectiveness of chlorine dioxide treatment and
the standard recommendations has been to maintain a final stage pH range for brightening with chlorine
dioxide between 3.5 and 4.0. But we used 16% & 17% TAA cooked Clone EH2013 of kappa number 18.7 &
17.4 without Oxygen Delignification (ODL), were bleached in Acidic and Alkaline pH initial chlorine dioxide
(DO) stage, followed by Caustic reinforced Hydrogen peroxide (Ep) and final Chlorine dioxide (D1) stage of
bleaching. At constant bleaching condition both EH2013 pulps show these alkaline pH bleaching methods can
improve the pulp bleachability without affecting pulp strength properties, optical properties, and physical
properties and improved effluent characteristics. The Alkaline pH bleached pulp final brightness 85.7 %ISO
(16% TAA) and 86.5%ISO (17% TAA) are well compared to Acidic pH final brightness 83.4 %ISO (16% TAA)
and 84.4%ISO (17% TAA) initial chlorine dioxide bleaching and followed by extraction reinforced Hydrogen
peroxide and final Chlorine dioxide bleaching. The fiber length, width and curl index of Acidic and Alkaline pH
bleached pulp has not shown any distinct variation, but alkaline pH bleached pulp has shown slightly higher
than Acidic pH bleached Pulp. Both 16&17% TAA cooked pulps filtrate analysis of the Alkaline pH Do stage,
shows lower Colour (14.6 & 15.4%), Total Dissolved Solids (10.7 & 17.9%) and COD (14.2 & 18.0%) than
Acidic pH Do bleaching filtrate. Based on results from the Acidic and Alkaline pH bleaching of EH2013 pulp ,
we found that the optimum pH for initial Do and final D1 chlorine dioxide bleaching stage should be operated
with a final pH close to alkaline, when a typical chlorine dioxide charge is applied and its effluent
characteristics shows lesser inorganic load when compared to acidic effluent .
The development of sustainable bioplastics for new applications in packaging ...Agriculture Journal IJOEAR
Abstract— The advantage of biodegradable plastics is their degradation under the influence of biological systems into substances naturally present in the environment, which are then placed in a natural circulation cycle of matter. Moreover, the biodegradable plastics waste not require additional segregation and separation from households, and are collected together with other organic waste and subjected to recycling under aerobic or anaerobic conditions. Use of bioplastics reduces the harmful effects of waste on the environment, but does not eliminate it completely.
The article presents the results of (bio) degradation studies under industrial and laboratory (MicroOxymax) composting conditions as well as at atmospheric conditions of commercial disposable dishes from the Nature Works® PLA. Were also carried out investigation of abiotic degradation under laboratory conditions. It was found, from the macro- and microscopic observations, that the tested cups (bio) degraded in the selected environments, wherein in a greater extent under industrial composting conditions than in MicroOxymax. The GPC results, which show significantly reduce in the molar mass of the tested samples after specified incubation times in all environments, indicates that the hydrolytic degradation process occurs predominantly.
The document summarizes methods for exfoliating and synthesizing molybdenum disulfide (MoS2) films and nanomaterials. It describes a representative procedure where powdered MoS2 is exfoliated using n-butyl-lithium in an argon atmosphere, forming a thin MoS2 layer after submersion in water. It also discusses coating a silicon wafer by dipping it in the solution and drying it. The document introduces that the research group aims to synthesize MoS2 through exfoliation and metal organic chemical vapor deposition for applications such as semiconductors and lubrication.
Modified magnetite nanoparticles with cetyltrimethylammonium bromide as super...Iranian Chemical Society
This paper reports application of cetyltrimethylammonium bromide (CTAB) coated magnetite nanoparticles (Fe3O4 NPs) as a novel adsorbent for removal of two types of disperse dyes, including disperse red 167, and disperse blue 183, from wastewater of textile companies. The effect of parameters including type of surfactant, pH of solution, surfactant concentration, and amount of salt, was investigated and optimized. The obtained results showed that the ratio of initial dye concentration to CTAB amounts has critical effect on removal processes so that removal efficiencies higher than 95% can be achieved even at high concentration of dyes as high as 500 mg l-1 when the ratio is optimum. Removal of dyes is very fast, and equilibrium is reached at times less than 10 min even for high concentration of the dyes. Very high adsorbent capacity (as high as 2000 mg g-1) was yielded for maximum tested concentration of the dyes (500 mg g-1). The obtained result was confirmed by thermogravimetric analysis data. This study showed that CTAB coated Fe3O4 NPs is a very efficient adsorbent for removal of dyes from wastewater of textile companies and has high capacity under optimum conditions.
This document summarizes a study on chlorine-free bleaching of kraft pulp produced from oil palm empty fruit bunches (EFB). Kraft pulping was performed on EFB under different conditions. The pulp was then bleached using an oxygen (O2) - acid (H2SO4) - ozone (O3) - hydrogen peroxide (H2O2) sequence. This chlorine-free bleaching reduced the kappa number significantly and achieved a brightness of around 75%, indicating the potential to reach 80% brightness without chlorine. Paper properties such as strength were maintained after bleaching despite reductions in viscosity. The bleached EFB pulp showed comparable strengths to hardwood pulps.
Utilization of Ca–Lignosulphonate Prepared From Black Liquor Waste as a Cement Superplasticizer Original Research Article
Original Research Article
Journal of Chemistry and Materials Research Vol. 1 (2), 2014, 28–34
H. H. M. Darweesh*
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
An Evaluation of Commercial Textile Tannins Based on Their Inert COD Content ...Tolga Tezgel
This study evaluated two common tannin formulations used in the textile dyeing process - Tannin 1 and Tannin 2 - to determine their inert chemical oxygen demand (COD) levels and toxicity. Both tannins had high levels of initially inert soluble COD, accounting for 59% and 41% of total COD respectively. Acute toxicity tests on bacteria Vibrio fischeri found that both tannins were toxic, with Tannin 2 showing considerably higher toxicity. The results indicate that effluents containing these tannins require specific pretreatment to reduce their recalcitrance and toxicity before mixing and conventional biological treatment.
Removal of Lignin from aqueous solution using Fe3O4 Nanoparticles as an effec...IJERA Editor
The study was carried out to find out the adsorption efficiency of lignin from paper mill waste water by using Fe3O4 magnetic nanoparticles. The physico-chemical analysis of paper mill effluent results high B.O.D value. Separations of lignin from black liquor were done by acid precipitation method and removal of lignin was done with nanoparticles. Synthesis of nanoparticles was done by co-precipitation method by mixing and stirring of FeCl3.6H2O and FeCl2.4H2O solution at 2:1 molar ratio. The nanoparticles were characterized by using U.V-Vis spectrophotometer and X-Ray Diffraction. U.V-Vis spectra show absorbance spectra at around 585 nm while XRD revealed around 10 nm sizes of Fe3O4 MNPs. The removal efficiency of lignin by Fe3O4 MNPs was investigated at different pH and contact time. Maximum adsorption of lignin onto the surface of Fe3O4 MNPs took place at pH 2.5 and 10 mins of contact time. Desorption of lignin by nanoparticles was studies by using different organic solvents.
Utilization of Banana Peel Powder in Concrete A Resultijtsrd
This document summarizes a study that analyzed the properties of concrete when banana peel powder is used as an admixture. The study found that the percentage of heat transmitted through concrete cubes and the time taken for the cubes to cool down were both reduced when banana peel powder was added, indicating that the exothermic chemical reaction in the concrete was decreased. Specifically, the heat transmitted was reduced by 12-16% and the cooling time was reduced by 2.5-4% compared to normal concrete without banana peel powder. The flexural strength of the concrete increased slightly with the addition of banana peel powder but the compressive strength did not change significantly. Therefore, the study concluded that banana peel powder can be used as a concrete admixture
A novel flame retardant application technique was developed for cotton apparel fabric using spirocyclic
pentaerythritol di (phosphoryl chloride) (SPDPC), which was further synthesized into bis diglycol spirocyclic
pentaerythritol bisphosphorate (BSPB). The flame retardant agent was then attached to the fabric using a
sol-gel process. The treated fabric was tested on a vertical flame tester which showed very high flame
retardancy as compared to the untreated cotton. TGA analysis exhibited a slow rate of weight loss and
higher ultimate degradation temperature for the FR treated sample. The FR treated sample showed modest
loss in strength while retaining 86.4% of its original strength. The fabric’s appearance did not alter and the
change in stiffness was insignificant as a result of the FR finish.
Synthesis, Characterization and Biological Evaluation of Substituted Thiazoli...paperpublications3
Abstract: A new series of substituted thiazolidin-4-ones were synthesized and evaluated for antimicrobial activity by means of zone of inhibition by cup plate method. The structures of these compounds were established by means by IR, H NMR analysis. All the compounds were evaluated for their antibacterial activity against gram positive and gram negative species and antifungal activity .Compounds TH09 & TH17 were found most active due to presence of electron withdrawing groups at appropriate position.
KINETIC STUDY OF ARTEFACT PAPER DEGRADATION. ASSESS MENT OF DEACIDIFICATION ...Michal Jablonsky
The present study investigates the stabilization of a 60 year old paper artefact via deacidification. Paper sheets
originating from a naturally-aged artefact book were subjected to accelerated ageing performed at 98 °C during 0, 3, 5,
10 and 15 days. A set of samples were deacidified before being subjected to accelerated aging. Deacidification was
performed using magnesium ethoxide and titanium ethoxide (METE) dissolved in hexamethyldisiloxane (HMDO) and
the properties of the thus treated samples were measured and compared to control samples. This study aims at finding
kinetic dependences for the decrease in the degree of polymerization and folding endurance of the paper subjected to
accelerated ageing. The deacidification effects were evaluated by the folding endurance of the paper artefact through
the multifactorial evaluation system developed by Consortium KnihaSK and Library of Congress.
Deep Eutectic Solvent Delignification: Impact of Initial LigninMichal Jablonsky
This study investigated the effect of initial lignin content in hardwood kraft pulps on pulp delignification using deep eutectic solvents (DESs). Pulps with different initial Kappa numbers were treated with four DES systems and oxygen delignification for comparison. The results showed that DES delignification decreased the Kappa number by 37.8-43.3% depending on the DES, with alanine:lactic acid being most efficient. DESs caused less degradation than oxygen delignification as shown by smaller decreases in viscosity and degree of polymerization. The pulp with higher initial lignin had a greater fraction of easily removed lignin fragments.
Accelerated ageing of newsprint paper: Changes in swelling ability, WRV and e...Michal Jablonsky
The present paper deals with the effect of accelerated ageing on the ability of fibres to undergo saturation with water and the corresponding swelling kinetics. Changes in the surface charge of aged paper fibres were also investigated. Accelerated ageing was performed with newsprint paper at 98 °C and 50% RH during 0, 3, 5,7, 10, 15, 20 and 30 days. The rate and maximum swelling of accelerated aged paper in water were obtained with a modified monitoring unit measuring wood swelling ability. Since paper swells extremely fast in water, even at 30 °C, this apparatus made it possible for the first time to obtain accurate kinetic data on aged paper swelling in water. The polyelectrolyte titration technique was used to investigate changes in the surface charge on fibres from accelerated aged paper.
This document summarizes a study that assessed the effects of adding different non-wood materials as additives to papermaking pulp. Materials tested included apple pulp, beer fines, beetroot pieces, citrus pulp, Betacal, deinking sludge, onion skins and sawdust. The study found that most additives improved pulp dewatering properties, with sawdust, Betacal and deinking sludge showing the most positive effects. Properties like ash content and initial dryness correlated with improved dewatering. However, the effects varied between virgin and recovered pulps. Overall, the additives showed potential to enhance pulp and paper properties but further investigation is needed.
This research article investigates total chlorine-free bleaching of poplar kraft pulp using Oxone. The pulp samples underwent a two-stage Oxone bleaching sequence after an acid pretreatment stage. Various reaction parameters were optimized in each stage. The final achieved brightness was more than 78% and accelerated aging experiments showed greater brightness stability for the Oxone treated pulp. The results demonstrate the feasibility and environmental benefits of Oxone for total chlorine-free bleaching compared to other bleaching methods.
Biological Removal of Malachite Green and Congo red by Some Filamentous FungiIJEAB
Four strains of filamentous fungi were studied to a removal of Malachite green (MG) and Congo red (CR). These fungi were Aspergillus niger ,Aspergillus flavus , Aspergillus versicolor and P. funigulosum. P. funigulosum showed that decolorization activity was higher than other fungi on solid medium containing MG and CR . The stastical method obtained that there was no significance between fungi . All these fungi were able to degradation dyes to other metabolites . The dry weight ( Biomass) of P. funigulosum reached to 1.10 ,1.02 in mineral salts medium (MSM) with MG and CR respectively , and the stastical methods obtained that there was no significance in dry weights between fungi .
4. optimization of culture condition for enhanced decolorization of reactive ...Darshan Rudakiya
Many synthetic azo dyes and their metabolites are toxic, carcinogenic, and
mutagenic so removal of azo dyes using cost-effective and eco-friendly method is
major aspect.Comamonas acidovorans MTCC 3364 has been routinely reported for
different steroid bioconversion and heavy metal removal. The main purpose of this
study is to check the decolorization efficiency of Comamonas acidovorans MTCC
3364 for different dyes and to optimize the condition which gives maximum
decolorization of Reactive Orange 16 dye. The effect of various physicochemical
parameters including condition, carbon and nitrogen sources, temperature,pH and
dye concentration were studied. The % decolorization of dye was determined by
UV Visible spectroscopy. This bacterial strain efficiently decolorizes Reactive
Orange 16 at 37oC, pH 6.85 within 24 hours giving 99.03 ± 0.5 % dye
decolorization under optimum environmental conditions.
Doped Titania Project Zinc Focus - George J. Ferko VGeorge Ferko
This document summarizes a study on the sintering behavior of titania doped with zinc, copper, and boron at concentrations of 1% and 10%. Titania has many industrial applications as a white pigment. The study examines how the dopants, doping levels, sintering temperature, and sintering time affect the densification and grain growth of the doped titania samples during conventional sintering. Samples were prepared through a multi-step process including mixing, calcining, pressing, and sintering. Microstructural analysis using SEM revealed that copper doped samples contained a second phase, zinc doped samples contained a second phase at higher temperatures, and boron doped samples exhibited abnormal
A Selective Study on Decolorization of Textile Azo Dye using Genetically Modi...BRNSS Publication Hub
This document summarizes research on using genetically modified brown-rot fungi to decolorize textile dyes. Brown-rot fungi naturally produce enzymes that can break down lignin and other complex molecules. The researchers genetically modified brown-rot fungi to enhance their ability to decolorize textile dyes. They tested the modified fungi on textile effluents and various dyes. The genetically modified brown-rot fungi showed improved ability to decolorize textile dyes compared to unmodified fungi. The document also describes techniques used to modify the fungi and evaluate their dye decolorization abilities.
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
The bleaching chemistry indicates that pH affects the effectiveness of chlorine dioxide treatment and
the standard recommendations has been to maintain a final stage pH range for brightening with chlorine
dioxide between 3.5 and 4.0. But we used 16% & 17% TAA cooked Clone EH2013 of kappa number 18.7 &
17.4 without Oxygen Delignification (ODL), were bleached in Acidic and Alkaline pH initial chlorine dioxide
(DO) stage, followed by Caustic reinforced Hydrogen peroxide (Ep) and final Chlorine dioxide (D1) stage of
bleaching. At constant bleaching condition both EH2013 pulps show these alkaline pH bleaching methods can
improve the pulp bleachability without affecting pulp strength properties, optical properties, and physical
properties and improved effluent characteristics. The Alkaline pH bleached pulp final brightness 85.7 %ISO
(16% TAA) and 86.5%ISO (17% TAA) are well compared to Acidic pH final brightness 83.4 %ISO (16% TAA)
and 84.4%ISO (17% TAA) initial chlorine dioxide bleaching and followed by extraction reinforced Hydrogen
peroxide and final Chlorine dioxide bleaching. The fiber length, width and curl index of Acidic and Alkaline pH
bleached pulp has not shown any distinct variation, but alkaline pH bleached pulp has shown slightly higher
than Acidic pH bleached Pulp. Both 16&17% TAA cooked pulps filtrate analysis of the Alkaline pH Do stage,
shows lower Colour (14.6 & 15.4%), Total Dissolved Solids (10.7 & 17.9%) and COD (14.2 & 18.0%) than
Acidic pH Do bleaching filtrate. Based on results from the Acidic and Alkaline pH bleaching of EH2013 pulp ,
we found that the optimum pH for initial Do and final D1 chlorine dioxide bleaching stage should be operated
with a final pH close to alkaline, when a typical chlorine dioxide charge is applied and its effluent
characteristics shows lesser inorganic load when compared to acidic effluent .
The development of sustainable bioplastics for new applications in packaging ...Agriculture Journal IJOEAR
Abstract— The advantage of biodegradable plastics is their degradation under the influence of biological systems into substances naturally present in the environment, which are then placed in a natural circulation cycle of matter. Moreover, the biodegradable plastics waste not require additional segregation and separation from households, and are collected together with other organic waste and subjected to recycling under aerobic or anaerobic conditions. Use of bioplastics reduces the harmful effects of waste on the environment, but does not eliminate it completely.
The article presents the results of (bio) degradation studies under industrial and laboratory (MicroOxymax) composting conditions as well as at atmospheric conditions of commercial disposable dishes from the Nature Works® PLA. Were also carried out investigation of abiotic degradation under laboratory conditions. It was found, from the macro- and microscopic observations, that the tested cups (bio) degraded in the selected environments, wherein in a greater extent under industrial composting conditions than in MicroOxymax. The GPC results, which show significantly reduce in the molar mass of the tested samples after specified incubation times in all environments, indicates that the hydrolytic degradation process occurs predominantly.
The document summarizes methods for exfoliating and synthesizing molybdenum disulfide (MoS2) films and nanomaterials. It describes a representative procedure where powdered MoS2 is exfoliated using n-butyl-lithium in an argon atmosphere, forming a thin MoS2 layer after submersion in water. It also discusses coating a silicon wafer by dipping it in the solution and drying it. The document introduces that the research group aims to synthesize MoS2 through exfoliation and metal organic chemical vapor deposition for applications such as semiconductors and lubrication.
Modified magnetite nanoparticles with cetyltrimethylammonium bromide as super...Iranian Chemical Society
This paper reports application of cetyltrimethylammonium bromide (CTAB) coated magnetite nanoparticles (Fe3O4 NPs) as a novel adsorbent for removal of two types of disperse dyes, including disperse red 167, and disperse blue 183, from wastewater of textile companies. The effect of parameters including type of surfactant, pH of solution, surfactant concentration, and amount of salt, was investigated and optimized. The obtained results showed that the ratio of initial dye concentration to CTAB amounts has critical effect on removal processes so that removal efficiencies higher than 95% can be achieved even at high concentration of dyes as high as 500 mg l-1 when the ratio is optimum. Removal of dyes is very fast, and equilibrium is reached at times less than 10 min even for high concentration of the dyes. Very high adsorbent capacity (as high as 2000 mg g-1) was yielded for maximum tested concentration of the dyes (500 mg g-1). The obtained result was confirmed by thermogravimetric analysis data. This study showed that CTAB coated Fe3O4 NPs is a very efficient adsorbent for removal of dyes from wastewater of textile companies and has high capacity under optimum conditions.
This document summarizes a study on chlorine-free bleaching of kraft pulp produced from oil palm empty fruit bunches (EFB). Kraft pulping was performed on EFB under different conditions. The pulp was then bleached using an oxygen (O2) - acid (H2SO4) - ozone (O3) - hydrogen peroxide (H2O2) sequence. This chlorine-free bleaching reduced the kappa number significantly and achieved a brightness of around 75%, indicating the potential to reach 80% brightness without chlorine. Paper properties such as strength were maintained after bleaching despite reductions in viscosity. The bleached EFB pulp showed comparable strengths to hardwood pulps.
Utilization of Ca–Lignosulphonate Prepared From Black Liquor Waste as a Cement Superplasticizer Original Research Article
Original Research Article
Journal of Chemistry and Materials Research Vol. 1 (2), 2014, 28–34
H. H. M. Darweesh*
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
An Evaluation of Commercial Textile Tannins Based on Their Inert COD Content ...Tolga Tezgel
This study evaluated two common tannin formulations used in the textile dyeing process - Tannin 1 and Tannin 2 - to determine their inert chemical oxygen demand (COD) levels and toxicity. Both tannins had high levels of initially inert soluble COD, accounting for 59% and 41% of total COD respectively. Acute toxicity tests on bacteria Vibrio fischeri found that both tannins were toxic, with Tannin 2 showing considerably higher toxicity. The results indicate that effluents containing these tannins require specific pretreatment to reduce their recalcitrance and toxicity before mixing and conventional biological treatment.
Removal of Lignin from aqueous solution using Fe3O4 Nanoparticles as an effec...IJERA Editor
The study was carried out to find out the adsorption efficiency of lignin from paper mill waste water by using Fe3O4 magnetic nanoparticles. The physico-chemical analysis of paper mill effluent results high B.O.D value. Separations of lignin from black liquor were done by acid precipitation method and removal of lignin was done with nanoparticles. Synthesis of nanoparticles was done by co-precipitation method by mixing and stirring of FeCl3.6H2O and FeCl2.4H2O solution at 2:1 molar ratio. The nanoparticles were characterized by using U.V-Vis spectrophotometer and X-Ray Diffraction. U.V-Vis spectra show absorbance spectra at around 585 nm while XRD revealed around 10 nm sizes of Fe3O4 MNPs. The removal efficiency of lignin by Fe3O4 MNPs was investigated at different pH and contact time. Maximum adsorption of lignin onto the surface of Fe3O4 MNPs took place at pH 2.5 and 10 mins of contact time. Desorption of lignin by nanoparticles was studies by using different organic solvents.
Utilization of Banana Peel Powder in Concrete A Resultijtsrd
This document summarizes a study that analyzed the properties of concrete when banana peel powder is used as an admixture. The study found that the percentage of heat transmitted through concrete cubes and the time taken for the cubes to cool down were both reduced when banana peel powder was added, indicating that the exothermic chemical reaction in the concrete was decreased. Specifically, the heat transmitted was reduced by 12-16% and the cooling time was reduced by 2.5-4% compared to normal concrete without banana peel powder. The flexural strength of the concrete increased slightly with the addition of banana peel powder but the compressive strength did not change significantly. Therefore, the study concluded that banana peel powder can be used as a concrete admixture
A novel flame retardant application technique was developed for cotton apparel fabric using spirocyclic
pentaerythritol di (phosphoryl chloride) (SPDPC), which was further synthesized into bis diglycol spirocyclic
pentaerythritol bisphosphorate (BSPB). The flame retardant agent was then attached to the fabric using a
sol-gel process. The treated fabric was tested on a vertical flame tester which showed very high flame
retardancy as compared to the untreated cotton. TGA analysis exhibited a slow rate of weight loss and
higher ultimate degradation temperature for the FR treated sample. The FR treated sample showed modest
loss in strength while retaining 86.4% of its original strength. The fabric’s appearance did not alter and the
change in stiffness was insignificant as a result of the FR finish.
Synthesis, Characterization and Biological Evaluation of Substituted Thiazoli...paperpublications3
Abstract: A new series of substituted thiazolidin-4-ones were synthesized and evaluated for antimicrobial activity by means of zone of inhibition by cup plate method. The structures of these compounds were established by means by IR, H NMR analysis. All the compounds were evaluated for their antibacterial activity against gram positive and gram negative species and antifungal activity .Compounds TH09 & TH17 were found most active due to presence of electron withdrawing groups at appropriate position.
KINETIC STUDY OF ARTEFACT PAPER DEGRADATION. ASSESS MENT OF DEACIDIFICATION ...Michal Jablonsky
The present study investigates the stabilization of a 60 year old paper artefact via deacidification. Paper sheets
originating from a naturally-aged artefact book were subjected to accelerated ageing performed at 98 °C during 0, 3, 5,
10 and 15 days. A set of samples were deacidified before being subjected to accelerated aging. Deacidification was
performed using magnesium ethoxide and titanium ethoxide (METE) dissolved in hexamethyldisiloxane (HMDO) and
the properties of the thus treated samples were measured and compared to control samples. This study aims at finding
kinetic dependences for the decrease in the degree of polymerization and folding endurance of the paper subjected to
accelerated ageing. The deacidification effects were evaluated by the folding endurance of the paper artefact through
the multifactorial evaluation system developed by Consortium KnihaSK and Library of Congress.
Deep Eutectic Solvent Delignification: Impact of Initial LigninMichal Jablonsky
This study investigated the effect of initial lignin content in hardwood kraft pulps on pulp delignification using deep eutectic solvents (DESs). Pulps with different initial Kappa numbers were treated with four DES systems and oxygen delignification for comparison. The results showed that DES delignification decreased the Kappa number by 37.8-43.3% depending on the DES, with alanine:lactic acid being most efficient. DESs caused less degradation than oxygen delignification as shown by smaller decreases in viscosity and degree of polymerization. The pulp with higher initial lignin had a greater fraction of easily removed lignin fragments.
Accelerated ageing of newsprint paper: Changes in swelling ability, WRV and e...Michal Jablonsky
The present paper deals with the effect of accelerated ageing on the ability of fibres to undergo saturation with water and the corresponding swelling kinetics. Changes in the surface charge of aged paper fibres were also investigated. Accelerated ageing was performed with newsprint paper at 98 °C and 50% RH during 0, 3, 5,7, 10, 15, 20 and 30 days. The rate and maximum swelling of accelerated aged paper in water were obtained with a modified monitoring unit measuring wood swelling ability. Since paper swells extremely fast in water, even at 30 °C, this apparatus made it possible for the first time to obtain accurate kinetic data on aged paper swelling in water. The polyelectrolyte titration technique was used to investigate changes in the surface charge on fibres from accelerated aged paper.
Analysis Of Degraded Papers By Infrared And Raman Spectroscopy For Forensic P...Nicole Heredia
The document discusses analyzing degraded paper samples using infrared and Raman spectroscopy for forensic purposes. Five types of office paper from different manufacturers were artificially aged in a climatic chamber at varying times and conditions. Infrared and Raman spectroscopy were used to examine the aged paper samples. 2D correlation analysis of infrared spectroscopy data was also performed to distinguish between samples and gain insight into the paper degradation mechanism. The analysis aims to determine if degraded paper samples can be differentiated based on aging effects observed in their spectroscopic signatures.
This document discusses the development of novel biopolymer blends based on poly(L-lactic acid) (PLLA), poly((R)-3-hydroxybutyrate) (PHB), and a plasticizer. PLLA has disadvantages like brittleness and a high glass transition temperature, making it unsuitable for food packaging. The researcher developed blends of PLLA, PHB, and tributyl citrate (TBC) plasticizer. The addition of PHB and TBC was found to increase polymer chain mobility, decrease the glass transition temperature of PLLA, and result in smaller spherulites. Characterization techniques showed the blends were miscible and PHB enhanced crystallization behavior by acting as
Fly ash from a coal power plant and waste glass were used to produce glass-ceramic composites. The addition of 50% flask glass to fly ash increased bending strength from 9 MPa to 77 MPa and elastic modulus from 6 GPa to 29 GPa. Porous composites made with polyurethane foam had 70% porosity, 3.5 GPa elastic modulus and 6 MPa bending strength. The composites showed good durability in acid with less than 0.05% mass loss, making them suitable for applications like filters or insulation.
Chlorine-Free Bleaching of Kraft Pulp from Oil Palm Empty Fruit BunchesWan Rosli Wan Daud
This document summarizes a study on chlorine-free bleaching of kraft pulp produced from oil palm empty fruit bunches (EFB). Kraft pulping was performed on EFB under different conditions. The pulp was then bleached using an oxygen (O2) - acid (H2SO4) - ozone (O3) - hydrogen peroxide (H2O2) sequence. This chlorine-free bleaching reduced the kappa number significantly and achieved a brightness of around 75%, indicating the potential to reach 80% brightness without chlorine. Paper properties such as strength were maintained despite reductions in viscosity during bleaching. The bleached EFB pulp showed comparable strengths to hardwood pulps, suggesting E
A test on the production of pulp and paper from
durian hides has been carried out with cooking temperature of
135 OC for a duration of 1.5 hours in a liquid of 2% : 3% : 4%
NaOH with comparison of durian hide fragment : cooking liquid
1:6. Durian hides possesses grinding level of 180 CSF, cracking
index of 0.6 kPa.m2
/gr and low tension index namely 15 Nm/gr.
The composition of the mixture of durian hide pulp (3% NaOH)
with Old Currugated Carbon (OCC) is (100%:0); (90%:10%);
(80%:20%), (70%:30%). To the grinding level of 300 ml CSF,
starch of 1% and sizing agent (AKD) 1% is added. Physical
characteristics of the paper sheet possesses gramature of 54.5
gr/m2
, thickness 0.321 mm, tensile strength 1.13 kN/m, tearing
strength 253 mN, Porosity (Bensten) 2050 ml/minute and
roughness (Bensten) 1700 ml/minute. The paper grammage had
not fulfilled basic paper specification for plastic laminated
wrapping paper, SNI 14-6519-2001.
The document summarizes research on the preparation of a titania intercalated graphite oxide hybrid material and its photocatalytic activity. Specifically, it discusses how vein graphite from Sri Lanka was oxidized to produce graphite oxide using Hummers' method. The graphite oxide was then exfoliated and used to intercalate with nano titanium dioxide synthesized from titanium oxysulfate. Characterization techniques showed the successful intercalation of TiO2 nanoparticles in the graphite oxide layers. Testing found the hybrid material demonstrated greater photocatalytic activity in degrading methyl orange under UV light compared to nano TiO2 alone, indicating its potential for applications in photocatalysis.
Test liner paper and folding carton from some lignocellulosic materialsIOSR Journals
This document summarizes research on producing test liner paper and folding carton from rice straw and bagasse using a semichemical pulping process. Key findings include:
- Semichemical pulping of rice straw and bagasse with 6% soda at 170°C for 2 hours produced pulps with yields of 63.1% and 73.6% respectively that showed promising paper and carton properties.
- Increasing NaOH concentration from 4-12% decreased bagasse pulp yield from 73% to 67.6% while increasing strength properties. For rice straw, yield decreased from 64.6% to 59% with NaOH from 4-8%.
- For both materials, 6%
The document discusses the conversion of waste plastics into fuel through a thermal degradation process without using catalysts or chemicals. None coded waste plastics are subjected to thermal cracking in a muffle furnace at 420°C and in a reactor from 300-420°C. This produces 85% liquid fuel, 9% light gases, and 6% carbon residue. Analysis of the produced fuel using GC/MS and FT-IR found it contains hydrocarbon compounds ranging from C3-C28, including alkanes and alkenes that could be used as a fuel or feedstock.
Determination of the diffusion of monovalent cations into wood under isotherm...Reddysuresh Kolavali
This document describes an experiment to determine the diffusion of lithium ions (Li+) into Norway spruce wood samples. Small wood pieces were impregnated with a lithium chloride (LiCl) solution for various time periods. The impregnated wood pieces were then cut into cubes and sliced thinly using a microtome. The slices were analyzed using flame atomic emission spectroscopy to measure the concentration of Li+ at different depths in the wood, allowing the development of concentration profiles. This experimental methodology provides a way to precisely measure cation diffusion and concentration gradients within impregnated wood pieces. The results help increase understanding of chemical transport processes during wood impregnation.
Determination of temperature regions in thermal degradation of ligninMichal Jablonsky
In this paper, industrial lignins were characterized by elemental analysis (EA) and thermogravimetry (TG). The aim was to find the main intervals of lignin degradation and maximum rate of their degradation. The results obtained can be helpful in finding the applicability of the materials at their thermal decomposition. The differences between individual lignins have been confirmed by EA and TG.
Thermal properties and size distribution of lignins precipitated with sulphur...Michal Jablonsky
Dissolution and fractionation of lignocellulosic material is a critical step of valorisation of lignins. Precipitated lignin was isolated from black liquor by sulphuric acid at four levels of concentration (5, 25, 50 and 72 % wt). A comparison study was performed through thermal and size properties. Theacid concentration influences of thermal properties of precipitated lignin. The acid concentration has an effect on changes in particle size of precipitated lignin. The results of thermogravimetric analysis indicated that the highest degradation of lignins appeared as an exothermic peak in range 470 - 650°C.The greatest weight loss in this section under an oxidation atmosphere was in the following order lignin 25 % wt (47.3 %), followed by lignin 72 % wt (45.0 %), lignin 5 % wt (43.6 %), and, smallest decline reached by lignin 50 % wt. The lowest temperature at the maximum degradation rate was determined for a sample of lignin 72 % wt at 488°C.
The document summarizes a study on the degradation of the synthetic polymer Nylon 6 through composting. Nylon 6 sheets were submerged in a semi-natural composting environment for 3 months. Analysis found a 10% reduction in weight and 13% reduction in thickness of the Nylon 6 sheets. Fourier transform spectroscopy and thermo gravimetric analysis indicated weakening of the amide bonds in the polymer and degradation through composting conditions. The study confirms that composting can actively degrade synthetic Nylon 6 polymer.
Non‒Conventional Light‒Weight Clay Bricks from Homra and Kraft Pulp Wastes
Original Research Article
Journal of Chemistry and Materials Research Vol. 1 (4), 2014, 123–129
H. H. M. Darweesh,* and M. G. El-Meligy
Batch adsorption experiments were carried out for
the adsorption of cationic dye from aqueous solution onto
composite activated carbon. The composite activated carbon was
prepared from brewer’s spent grain and sea bean shell at a ratio
of 1:1. The equilibrium studies were done at different
concentrations and temperatures. The equilibrium data were
fitted to Langmuir, Freundlich, Dubinin-Radushkevich, and
Temkin isotherm models. The results showed that both Lagmuir
and Freundlich isotherm model fitted the data reasonably well
but Freundlich isotherm fitted better in the temperature range
studied. This confirmed that the adsorption is heterogeneous,
non-specific and non-uniform in nature. Kinetic studies were also
undertaken in terms of first order, second order, pseudo first
order, pseudo second order, Elovich, Boyd, and intra-particle
diffusion models. The results indicated that the data followed
pseudo second order model with surface adsorption and intraparticle
diffusion concurrently operating during the adsorbateadsorbent
interaction. The values of the thermodynamic
parameters computed from Van’t Hoff plot confirmed the
process to be endothermic and spontaneous in nature.
Utilization of waste paper sludge in construction industrySandeep Jain
This technical note is recapitulation of the work carried out by researchers round the globe on characterization of waste paper sludge based on physical, chemical and mineralogical properties, activation mechanisms, pozzolanic reactivity, reaction kinematics and durability; for its possible utilization in construction industry as supplementary cementitious material, mineral admixture, partial replacement of binders in concrete, raw material for clay brick manufacturing, production of ceramics, soil stabilization in road works, reduction in carbon-dioxide emission etc., in order to encash various socio-economic and environmental benefits.
1) PET waste was chemically recycled using a glycolysis process with diethylene glycol to produce oligomers.
2) An unsaturated polyester resin was synthesized from the glycolysis products and maleic anhydride via polycondensation.
3) The unsaturated polyester resin was cross-linked with styrene to produce molded compounds for construction applications like panels or partitions. Mechanical testing showed the cross-linked materials had good compression strength and impact resistance.
Chemical factors of deterioration of documentsDr. Utpal Das
This document discusses chemical factors that contribute to the deterioration of documents, including acidity, browning of paper, reactions with ink, and the actions of pigments. It focuses on acidity, which can intrinsically exist in wood-origin manuscripts and papers due to various acidic components. Acidic gases in the air can also deteriorate documents through chemical reactions with cellulose. The document then examines specific chemical issues like browning of paper through oxidation, damage caused by acidic iron-gall ink, and reactions of some metal-based pigments. It concludes by outlining several deacidification processes pioneered by W.J. Barrow to neutralize acidity, including using calcium hydroxide, calcium bicarbonate
Similar to FORMATION OF ACETIC AND FORMIC ACID IN UNMODIFIED AND MODIFIED PAPERS DURING ACCELARATED AGEING (20)
Green solvents show several favorable features to be used as extraction and fractionation solvents, such as their ease of preparation and lower cost, and they can be both non-toxic and biodegradable when prepared with natural compounds. Due to their properties, green solvents' application in biomass fractionation has been extensively studied during the past years. The presented work describes the application of several possible combinations to create deep eutectic solvents with the potential to be used in processing different types of biomass. The results of studies suggest that deep eutectic solvents may have an important ability to dissolve lignin molecules from plants and can realize a mild catalytic mechanism (acid-base) that will activate the checked cleavage of non-stable ether linkages between phenylpropane units.
Phytomass valorization by deep eutectic solvents - achievements, perspectives...Michal Jablonsky
In recent years, a plethora of extraction processes have been performed by a novel class of
green solvents known as deep eutectic solvents (DESs), possessing several environmental, operational,
and economic advantages proven by experience when compared to organic solvents and ionic
liquids. The present review provides an organized overview of the use of DESs as extraction
agents for the recovery of valuable substances and compounds from the original plant biomass,
waste from its processing, and waste from the production and consumption of plant-based food.
For the sake of simplicity and speed of orientation, the data are, as far as possible, arranged in
a table in alphabetical order of the extracted substances. However, in some cases, the isolation
of several substances is described in one paper and they are, therefore, listed together. The table
further contains a description of the extracted phytomass, DES composition, extraction conditions,
and literature sources. With regard to extracted value-added substances, this review addresses their
pharmacological, therapeutic, and nutritional aspects. The review also includes an evaluation of
the possibilities and limitations of using DESs to obtain value-added substances from phytomass.
Involvement of Deep Eutectic Solvents in Extraction by Molecularly Imprinted ...Michal Jablonsky
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Investigation of Total Phenolic Content and Antioxidant Activities of Spruce ...Michal Jablonsky
Extracts from spruce bark obtained using dierent deep eutectic solvents were screened for
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deep eutectic solvents (DESs) with lactic acid and 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and
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as Newtonian liquids. The extractions were performed for 2 h at 60 C under continuous stirring.
TPC was determined spectrophotometrically, using the Folin-Ciocalteu reagent, and expressed as
gallic acid equivalent (GAE). The antioxidant activity was determined spectrophotometrically by
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596.2 mg GAE/100 g dry bark; radical scavenging activity (RSA) ranged between 81.4% and 95%.
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Deep Eutectic Solvents: Fractionation of Wheat StrawMichal Jablonsky
Deep eutectic solvents (DESs) are a relatively new topic in science. Their usage is not yet clearly defined, and the areas in which DESs may be applied are constantly growing. A simple and clean fractionation of the main components of biomass represents a very important step in creating a clean, renewable carbon economy. A major challenge is the use of DESs for fractionation of biomass components at lower temperatures, without the use of expensive raw materials. In this work, wheat straw was pretreated with six different DES systems composed of choline chloride with urea (1:2), malonic acid (1:1), lactic (1:9; 1:10), malic (1:1), and oxalic acid (1:1). The pretreated biomass was characterized in terms of lignin content, ash, and holocellulose. A deep eutectic solvent, composed of choline chloride and oxalic acid, was found to produce the best delignification results. The solvents are not selective in the process of delignification.
CITE: Hodasova, L., Jablonsky, M., Skulcova, A., Haz, A. (2015). Lignin, potential products and their market value. Wood Research, 60(6), 973-986.
Author "Michal Jablonsky" gives permission to use information and pictures from publications
Lignin is one of the important components in the valorization of lignocellulosic biomass. Lignin-based materials and chemicals represent potential value-added products for biorefineries. Lignin products have numerous applications and can be divided into three main groups. Group, in which lignin is fragmentized into smaller aromatic compounds such as phenol or benzene, toluene and xylene, is less developed than group where lignin is used as macromolecule, but has greater potential. Lignin as macromolecule is used as additive or polymer blend. Last group of lignin products are carbon materials, which include carbon fibres.
Cellulose protectors for improving ozone bleaching - reviewMichal Jablonsky
The document reviews cellulose protectors that have been used to improve ozone bleaching processes. It systematically classifies protectors into 7 chemical groups and evaluates their effects on viscosity, kappa number, and brightness compared to bleaching without protectors. Alcohols and carboxylic acids are generally the most effective, positively impacting lignin removal while preventing carbohydrate degradation. Inorganic additives usually show no benefits. The protectors are thought to work by scavenging radicals, selective adsorption to cellulose, or forming protective compounds on the cellulose surface. Overall, no single protector was identified that strongly promotes lignin removal without also degrading cellulose.
Mechanical Properties of Pulp Delignified by Deep Eutectic SolventsMichal Jablonsky
Mechanical properties were evaluated for pulp delignified by four deep eutectic solvents (DES). The DES systems were based on choline chloride and lactic acid (1:9), oxalic acid:dihydrate (1:1), malic acid (1:1), and the system alanine:lactic acid (1:9). The results indicated that the type of DES system used influenced the delignified pulp's mechanical properties including tensile, burst and tear indexes, tensile length, and stiffness. The most suitable DES systems were choline chloride:malic acid (1:1) and alanine:lactic acid (1:9), which achieved the best aforementioned mechanical properties compared to the other DES systems. The weakest performance in the process of pulp delignification was the system with choline chloride and oxalic acid dihydrate (1:1).
The pH Behavior of Seventeen Deep Eutectic SolventsMichal Jablonsky
Deep eutectic solvents (DESs) are a unique category of green solvents that have gained attention in biomass processing due to their distinctive properties not offered by traditional solvents. The pH behavior of 17 selected DESs along with their temperature dependence on pH were evaluated in this study. For all investigated DESs, a temperature increase caused a decrease in pH value.
UV/Vis Spectrometry as a Quantification Tool for Lignin Solubilized in Deep E...Michal Jablonsky
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THERMAL STABILITY OF SELECTED DEEP EUTECTIC SOLVENTSMichal Jablonsky
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Behaviors of Pulp During Delignification in Solutions of Deep Eutectic Solven...Michal Jablonsky
In this short communication, the degradation of cellulose for delignified pulp by deep eutectic solvents was evaluated. The pulp was delignified using different DES systems based on choline chloride and lactic acid (1:9), oxalic acid dehydrate (1:1), malic acid (1:1), and system alanine : lactic acid (1:9). This paper shows that cellulose degradation can be characterized in terms of the percentage degree of polymerization loss of cellulose. Among the investigated DES (Choline chloride:oxalic acid; choline chloride:malic acid; alanine:lactic acid; choline chloride:lactic acid), the most suitable seemed to be a treatment using the alanine:lactic acid system that provided a relatively low degradation of cellulose and high delignification efficiency for the removed of lignin from pulp.
Long-term Isothermal Stability of Deep Eutectic SolventsMichal Jablonsky
Deep eutectic solvents play an important role in the clean production of chemicals and the fractionation of renewable sources. When dissolving lignin or cellulose at elevated temperatures, the thermal stability of deep eutectic solvents is of great importance. However, studies concerning the long-term isothermal stability of deep eutectic solvents are scarce. In this study, the thermal stability of deep eutectic solvents, namely, choline chloride with oxalic acid dihydrate, glycerol, glycolic, malic acid, and citric acid monohydrate were investigated using thermogravimetric analysis (TGA). The isothermal decomposition experiments were conducted at a constant temperature (60, 80, 100, and 120 °C) for 10 h. These long-term isothermal thermogravimetric studies of the deep eutectic solvents showed a non-linear weight loss as a function of time at each temperature. According to these studies it is recommended to perform fractionation or dissolution of biomass below 80 °C.
Swelling properties of pulp treated with deep eutectic solventsMichal Jablonsky
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solvents affects the swelling kinetics of the fibres. Unbleached kraft pulp was treated with three deep eutectic solvents containing choline chloride (ChCl) – ChCl:lactic acid (1:9), ChCl:oxalic acid (1:1) and ChCl:malic acid (1:1) – and with the system alanine:lactic acid (1:9). The rate and maximum swelling of the
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Determination of the Thermal Oxidation Stability and the Kinetic Parameters o...Michal Jablonsky
The use of olive oil with cooking purposes, as final seasoning or within cooked foods is increasing worldwide due to its numerous nutritional and health benefits. These attributes are mainly determined by olive oil chemical composition, which can be altered after thermal processing, oxidation processes, or incorrect practices. For this reason, and due to the numerous factors which have influence in olive oil quality, the correct chemical characterization is highly relevant. In this study, fatty acid composition of four extra virgin olive oil (EVOO) varieties was studied. The major fatty acid (FA) determined was oleic acid (77.1% on average), followed by palmitic (11.5% on average). In addition, thermal oxidation behaviour of the four EVOO samples was studied as an indicator of their quality and stability during thermal processing. This was performed through differential scanning calorimetry (DSC) from a temperature of 40°C at six different heating rates in the range of 0.5–10°C min ⁻¹ . DSC records showed the same pattern and a small shoulder in the thermo-oxidation peak was present for all samples and all heating rates. The presence of initial and final oxidation products (by monitoring K232 and K270 values, respectively) was discarded according to the International Olive Council method.
Pharmacokinetic Properties of Biomass-extracted Substances Isolated by Green ...Michal Jablonsky
According to the literature, approximately 41 nutraceutical compounds have been isolated from different types of biomass using green solvents. It is important to collect information on the pharmacokinetic properties of the nutraceutical substances from biomass isolated according to the published papers. The pharmacokinetic properties of the bioactive substances extracted by green solvents, such as the molecular weight, logP, AlogP, H-bond acceptor, H-bond donor, total polar surface area, atom molar refractivity, number of rotatable bonds, number of atoms, rotatable bond count, number of rigid bonds, number of atom rings, and number of H-bonds, were calculated with a drug-likeness tool. In practical terms, the original and most well-known Lipinski's Rule of Five (Ro5) was applied to 28 substances, namely 3-hydroxytyrosol; apigenin; artemisinin; bergapten; bilobalide; biochanin A; caffeic Acid; caffeoylmalic acid; catechins; cinnamic acid; curcumin; daidzei; daidzin; epicatechin; gallic acid; genistein; ginkgolide A; ginkgolide B; levofloxacin; luteolin; naringenin; p-coumaric acid; protocatechuic acid; psoralen; quercetin; trans-ferulic acid; tyrosol, and vanillin.
Chemical Composition and Thermal Behavior of Kraft LigninsMichal Jablonsky
Lignin has great potential for utilization as a green raw material or as an additive in various industrial applications, such as energy, valuable chemicals, or cost-effective materials. In this study, we assessed a commercial form of lignin isolated using LignoBoost technology (LB lignin) as well as three other types of lignin (two samples of non-wood lignins and one hardwood kraft lignin) isolated from the waste liquors produced during the pulping process. Measurements were taken for elemental analysis, methoxyl and ash content, higher heating values, thermogravimetric analysis, and molecular weight determination. We found that the elemental composition of the isolated lignins affected their thermal stability, activation energies, and higher heating values. The lignin samples examined showed varying amounts of functional groups, inorganic component compositions, and molecular weight distributions. Mean activation energies ranged from 93 to 281 kJ/mol. Lignins with bimodal molecular weight distribution were thermally decomposed in two stages, whereas the LB lignin showing a unimodal molecular weight distribution was decomposed in a single thermal stage. Based on its thermal properties, the LB lignin may find direct applications in biocomposites where a higher thermal resistance is required.
Nutraceuticals as phenolic bioactive compounds analysis of softwood bark and ...Michal Jablonsky
Softwoods have a numerically large group of economically important renewable plants. Waste processing of trees mainly bark, needles are reasonable extent not recovered. The waste contains relatively high levels of phenolic compounds. Phenolic compounds are one of the main components that have a high potential in various fields of food, pharmacy, and other industries. This review focuses on the main uses of softwood bark and overviews the extraction and analytical methods used to determine phenolic bioactive compounds in this matrix. At this time, various extraction techniques are used to obtain secondary metabolites from bark mainly bio-active phenolic compounds. The amount of bioactive compounds derived from the matrix affects the: extraction conditions, choice of the solvent, particle size, content of the water and, in particular, the extraction method. Amount and nature of the isolated compounds greatly depend on the isolation; the isolation is possible to use different methods: extraction in a Soxhlet apparatus, Soxtec extraction, accelerated solvent extraction, ultrasound-assisted, supercritical fluid extraction, pressurized liquid extraction, and microwave assisted extraction. According to literature were selected nutraceuticals phenolic compounds (isolated from softwood bark):Astringin; Catechin; Epicatechin; Ellagic acid; Ferulic acid; Gallic acid; Hydroxymatairesinol; isolariciresinol; Isorhapontigenin; Isorhapontin,lariciresinol; Lariciresinol-9-p-coumarate; Methylthy mol;p-Coumaric acid; Piceatannol; Piceid; Podocarpic acid; Quercetin; Resveratrol; Sesquipinsapol B; Sinapic acid; Tannic acid; Taxifolin; Vanillic acid; Vladinol D. From this viewpoint, it is important to collect information on pharmacokinetic properties of the nutraceuti- cal phenolic substances isolated from bark according to published papers. Pharmacokinetics properties of phenolic bioactive substances extracted by different techniques such as: molecular weight, logP, AlogP, H-bond acceptor, H-bond donor, total polar surface area, atom molar refractivity, number of rotatable bond, number of atom, rotatable bond count, number of rigid bond, number of atom ring, and number of Hydrogen Bond were calculated by DruLito (Drug LiknessTool).
Determination of volatile organic compounds emissions from wood processingMichal Jablonsky
Volatile organic compounds (VOCs) have received a great deal of attention due to their high abundance during the drying process of wood particles. This is a potential environmental issue due to being low level ozone precursors. This work aimed to study the emissions of VOCs during drying in the particleboard manufacturing process. In this study, wood particles were dry and VOCs were collected using a sorption tube. The VOCs were analyzed with gas chromatography-mass spectrometry to explore the effect of temperature on the composition of main components. The results indicated that α-pinene and D-limonene were the dominant components. The results also indicated that using natural gas or wood dust as a heat source did not have a major impact on the emission characteristics of VOCs.
Assessing the main opportunities used of biomass, biowaste from forestry, agr...Michal Jablonsky
Valorisation of biomass and food-related wastes including extraction of value-added compounds from these sources represent a dynamically developed area of research and technology. Substantial research activity has been focused on the new types of extraction and refining processes during the last decades. In the presence of green solvents such as deep eutectic solvents (DESs), naturally deep eutectic solvents (NADESs), and low-transition temperature mixtures (LTTMs) the interest for the recovery of new products and bioactive compounds usable as additives and functional ingredients in industrial food sector with the aim to enhance food quality has been renewed and reinforced. DESs, NADES, and LTTMS are attractive solvents for the deconstruction/fractionation (or pretreatment) of biomass and modification of cellulose. The scope of this study consists in identifying the nutritional and nutraceutical potential of raw by-products, and in using possible processes for the production of individual compounds by separation, fractionation, and extraction. Another section is oriented on the application green solvents for fractionation of biomass or delignification/modification of pulp, and their valorisation for the product of added value (fibres, cellulose nanofibrils, cellulose nanocrystals). Acknowledgement This work was supported by the Slovak Research and Development Agency under the contracts No. APVV-15-0052, APVV-0393-14, APVV-16-0088 and VEGA grant 1/0403/19.
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FORMATION OF ACETIC AND FORMIC ACID IN UNMODIFIED AND MODIFIED PAPERS DURING ACCELARATED AGEING
1. CELLULOSE CHEMISTRY AND TECHNOLOGY
Cellulose Chem. Technol., 46 (5-6), 331-340 (2012)
FORMATION OF ACETIC AND FORMIC ACID IN UNMODIFIED AND
MODIFIED PAPERS DURING ACCELARATED AGEING
MICHAL JABLONSKY, KATARINA HROBONOVA,*
SVETOZAR KATUSCAK,
JOZEF LEHOTAY*
and MARTINA BOTKOVA
Department of Chemical Technology of Wood, Pulp and Paper, Faculty of Chemical and Food Technology,
Slovak University of Technology, Bratislava, Slovak Republic
*
Department of Analytical Chemistry, Faculty of Chemical and Food Technology, Slovak University of
Technology, Bratislava, Slovak Republic
Received April 14, 2011
Organic acids are spontaneously generated in significant concentrations during natural ageing of all cellulose-based
papers, the alkaline ones included. The present study reviews the paper degradation research devoted to the
identification and determination of the role of light products formed during paper ageing. Accelerated ageing was
performed at 98 °C and 50% RH, for 60 days. The main objective of the present study was to investigate the influence
of the Mg cations included in the alkaline reserve on the progress of degradation during accelerated ageing of paper.
The changes in the ratio of acetic/formic acids and the role of Mg2+
ions during accelerated ageing – in the investigated
unmodified and modified papers – with dispersion of MgO or MgO and MMMC (methyl methoxy magnesium
carbonate) mixture are discussed. The obtained results show that, during accelerated ageing, acetic and formic acids are
produced in both unmodified and modified papers. The higher content of Mg2+
ions in modified paper increases the
formation of acetic and formic acids more than in unmodified paper. The reason for this behaviour might be the strong
promoting role played by the Mg2+
ions in the formation of the mentioned organic acids.
Keywords: acetic acid, formic acid, degradation, Mg2+
ions
INTRODUCTION
Paper degradation is an inevitable process,1
related to the presence of acid substances,
moisture, light/UV radiation,2-5
heat/
temperature,6,7
oxidative agents8-11
or
microorganisms.12-14
It has been shown that
deterioration of the mechanical properties of
paper through ageing is caused by the presence of
acids in the sheet.15-17
In time, hydrolysis18-21
and
oxidation,18-23
occurring during cellulose ageing,
result in a progressive weakening of the physical
strength of paper.24
The influence of the oxidation
process leads to the formation and release of the
degradation products containing a carbonyl group
(C=O) and the double bond (C=C).25-26
Paper
degradation is associated with the formation of
low molecular products, such as formic, acetic,
lactic acids and others. Several researchers have
pointed out the important role played by acidic
degradation products (VOCs) in paper ageing and
several analytical methods have been developed
for the extraction and determination of volatile
compounds.27-45
Other analytical techniques
applied, including gas (GC) and liquid
chromatography (LC), have identified a few low
molecular weight acids, namely acetic, propionic
and levulinic acids.46
It has been reported that the
regression between them and other cellulose and
hemicellulose degradation products, as well as the
paper strength parameters, have been evaluated by
multivariation data analyses.47
In the USA, the National Institute for
Standards and Technology completed a
preliminary study concerning the identification of
degradation products both in the presence and
absence of sulphur dioxide.48
It has been shown
that several organic acids (formic, acetic, lactic
acids) are spontaneously generated in significant
concentrations during the natural ageing of all
cellulose-based papers, including alkaline papers
containing alkaline fillers. Easily detectable
2. MICHAL JABLONSKY et al.
332
concentrations of formic, acetic, lactic, glycolic,
oxalic and a few other unidentified acids
accumulate within a few months, following the
manufacture of paper stored under ambient
conditions.49
Earlier works showed that acidic
degradation products tend to accumulate inside
polyester encapsulations and other enclosures,
thereby speeding up paper ageing.50,51
The fact that acidic degradation products are
produced during accelerated ageing of acidic
paper in a humid environment was clearly
established at NBS in the seventies.52
However,
these data did not discuss the accumulation of
these acids within a paper mass, such as a book,
and the subsequent autocatalytic nature of the
degradation process. Bigourdan and co-workers53
reported that the capacity of paper loaded with an
alkaline reserve to neutralize the exposure to
acetic acid was not directly correlated to its initial
concentration. A significant amount of absorbed
acetic acid can coexist with the residual alkaline
reserve in the paper structure.
To stop degradation and save the millions of
books stored in archives, different technologies of
deacidification and fibre strengthening were
invented, and considerable efforts have been
devoted to finding new additives, such as
scavengers of the free radicals, natural and
synthetic compounds, inorganic compounds,
solvent and improved original technologies of
deacidification.54-56
The present work investigates
the formation of acetic and formic acids and their
molar ratio, in unmodified and modified paper,
with dispersion of MgO or MgO and MMMC
(methyl methoxy magnesium carbonate) mixture,
during accelerated ageing at 98 °C and 50% RH.
EXPERIMENTAL
Raw material
Commercial wood-containing newsprint paper
(grammage: 45 g/m, pH determined by cold extraction:
4.5-5.0), containing mechanically bleached
groundwood (55%), bleached sulphite pulp (20%),
recycled fibres (15%) and clay (10%) was used in all
experiments.
The newsprint paper used in the experiments was
directly made per order, based on the requirements of
the Project “Preservation, stabilization and
conservation of the traditional information supports in
the Slovak Republic” (KnihaSK
). This type of paper has
a selected composition, to reflect the paper quality of
the most endangered books in a library of the Slovak
Republic, in terms of pH and content of the
mechanically bleached groundwood pulp.
Accelerated ageing at 98 °C
The paper samples were conditioned according to
TAPPI T402 om-93 at 23 ± 1 °C, and relative air
humidity, RH = 50 ± 2%. The samples were divided
into 3 groups. All samples reached equilibrium
moisture content, the paper moisture content ranging
between 4.1-5% for samples A, 3.7-4.3% for samples
B and 3.8-4.9% for samples C.
Samples A: The samples were subsequently aged
according to ISO 5630-05, at a modified temperature
of 98 ±2 °C (instead of 100 °C), and 50% RH,
corresponding to a paper humidity of 4.1-5%. Twenty
sheets of paper (A4 format) were encapsulated inside
a polyethylene/aluminium/polypropylene (PET/Al/PE)
composite foil (Tenofan Al/116S), by sealing off all
four edges, using a Polystar 30D impulse tong sealer
(Rische&Herfurth, Hamburg, Germany). The bag was
put into another PET/Al/PE bag and completely sealed
off. Batches of samples were put into the thermostate
for 0, 1, 2, 3, 5, 7, 10, 15, 20, 30 and 60 days and kept
at 98 ± 2 °C, according to ASTM D 6819-02: Standard
test method for accelerated ageing of printing and
writing paper, by means of a dry oven exposure
apparatus, in which the sealed glass tubes were
replaced by a composite foil made of PET/Al/PE.
Humidity inside the bag during accelerated ageing was
of 50 ± 2%, and the free air volume in the bag was of 5
± 1 mL. After ageing, the papers were conditioned for
testing according to TAPPI T402 om-93.
Samples B: The specimens (books with 320 sheets
of paper, A5 format) were modified by Bookkeeper
dispersion of MgO, at a concentration of 4.3 g/dm3
(particle size below 1 μm in the dispersing blend of
C5-C18 perfluoralkanes and below 0.1%
perfluorinated Mg-soap surfactant in equipment DP 7).
Samples C: The specimens (books with 320 sheets
of paper, A5 format) were modified by a (3:1)
Bookkeeper dispersion mixture of MgO (3 L) and
MMMC (1 L). The MMMC solution was prepared
through dilution from a 10% methanol solution of
MMMC. Impregnation was carried out in equipment
DP 7.
A DP7 universal laboratory modifier device with
changeable reactors and a capacity of 1, 2 and 7 L was
used for process modification, for exothermic
polymerization processes, in situ polymer analogous
reactions, cold impregnation, Rueping and other
impregnation processes with controlled distribution of
the impregnating substances in the cells.
The specimens (books with 320 sheets of paper, A5
format) were modified in equipment DP7. The
specimen for impregnation was fixed into a holder of
the rustles, then opened, a tip jet being placed in the
middle of the book. After evacuation of the reactor,
predrying at 55 °C, at a pressure 0.1 MPa was carried
out for 4 h. During evacuation, an impregnation
solution (4 L) was added and circulated in the reactor
for 20 min, at a pressure of 0.1 MPa. Forty paper
sheets modified with MgO and, respectively, MgO and
3. Paper ageing
333
MMMC dispersion (twenty sheets of paper, A5 format
being placed abreast) were encapsulated inside the
sheets of the PET/Al/PE film by sealing off completely
all four edges. The bag was encapsulated inside the
sheets of the PET/Al/PE film by completely sealing
out all four edges, the procedure being repeated. The
bag of samples was thermostated from 0 to 30 days at
98 ± 2 °C and 50 ± 2% RH. After ageing, the papers
were conditioned for testing, according to
TAPPI T402 om -93.
High-performance ion-exchange chromatography
Materials
Sulphuric acid and acid standards (acetic and
formic acids) of highly pure grades were purchased
from Merck. The water used in the eluent was purified
by a Millipore Elix 5 system.
Sample preparation
Approximately 2 g of paper were accurately
weighed and 15 mL of pure water (resistivity at 25 °C
> 5 MΩ.cm, TOC <30 µg/L) were added. The mixture
was mixed for 2 h and subsequently filtered through a
0.45 μm filter, and 20 μL of filtrate were injected into
the analytical column.
Instruments and conditions
The used HPLC system consisted of a DeltaChrom
SDS 030 isocratic pump, a 7125 Rheodyne injector
with a 20 μL injection loop, a thermostate Model LCT
5100, a Knauer variable wavelength detector (set at
210 nm), and a CSW32 software for peak
identification and integration. Chromatographic
separations of acids were performed with a Polymer
IEX H-form column (250 x 8 mm I.D., 8 μm). The
mobile phase included 9 mmol/L sulphuric acid. The
column temperature was set at 20 °C and the flow rate
of the mobile phase was of 0.8 mL/min.
Identification and quantification
Formic and acetic acids were detected
spectrophotometrically at 210 nm. The retention times
were of 9.7 ± 0.2 min and 10.7 ± 0.1 min for formic
and acetic acids, respectively. The identification of
acids in the water extract of paper was based on the
comparison of their retention factors (formic acid k =
1.21 ± 0.03, acetic acid k = 1.44 ± 0.03).
Calibration curves were constructed by performing
a regression linear analysis of the peak area versus the
concentration of the acids. Based on a four-point
calibration, a linear response (R = 0.99) was observed
from the limit of determination to 20 mg/mL of the
studied acids.
The detection limits were of 10.7 μg/mL for formic
acid and of 18.4 μg/mL, respectively, for acetic acid,
while the determination limits were of 42.8 μg/mL for
formic acid and 92.2 μg/mL for acetic acid,
respectively.
Cold extract pH
Cold extract pH was measured according to TAPPI
T 509 om-02 (cold extraction, 1 g samples per 70 mL
of water, 1 h). The precision in the pH determinations
of the cold extract is estimated to be <± 0.2 units.
MIT double folds
Folding endurance (load 0.3 kg) was determined
according to TAPPI T511 om-88.
RESULTS AND DISCUSSION
Figure 1 illustrates the cold extract pH/time for
accelerating ageing at 98 °C and 50% RH, in
unmodified and modified paper. The influence of
accelerated ageing leads to a decrease of pH with
prolonged ageing of all specimens. In unmodified
samples, the value of cold extract pH decreased
from 6.65 to 5.24 (after 30 days). The effect of
modification was to increase pH – when the B
samples were modified by MgO, the pH ranged
from 9.21 to 5.24. In cold extract C specimens,
during accelerated ageing, pH ranged from 10.43
to 10.07. The influence of accelerated ageing on
pH decrease does not reach a considerable value
at accelerated ageing with modification by a
mixture of MgO and MMMC (a decrease of 0.36
in pH after 30 days of ageing). In the case of the
modification with the dispersion of MgO, after 30
days, pH decreased by about 3.97. In the
unmodified A samples, the pH decrease was of
1.59 after 30 days.
The continual doubt on whether to use Mg2+
-
based deacidification solution was the subject of
many studies.57-60
From the above considerations,
two effects can be taken into consideration,
namely: the effect of a higher solubility of
MgCO3, inducing higher pH values of MgCO3-
containing papers, and the effect of the cation.61
Bielikova62
found out that the distribution of
magnesium in paper modified using a MgO
dispersion in perfluoroheptane was
inhomogeneous. It was shown that MgO was
present on the surface and in the paper pores,
which are larger than the dispersed particles of
MgO in perfluorheptane (particle sizes below 1
m). Energy dispersive spectroscopy has shown
that the magnesium ions and their compounds
with multicomponent agents and mixtures
containing a chemical solution with low
molecular compounds (MgO and MMMC)
diffuse into the paper structure more
homogenously than the MgO particles.
Consequently, the insufficiency of the
dispersed MgO particles present in paper may be
4. MICHAL JABLONSKY et al.
334
less effective on the removal of carboxylic
acids.63-64
Table 1 lists the concentration of formic and
acetic acids as a function of time in accelerated
ageing for the samples of studied papers,
modified by two processes in the DP 7
equipment. For samples B, the content of MgO in
1 g paper was of 1.44 0.98 mg MgO/g paper,
while for the MgO and MMMC mixture, it was of
21.11 1.34 mg MgO/g paper. On the basis of
this evaluation of the contents of carboxylic acids
(formic and acetic acids), an unambiguous
increase in the concentration of acetic acid during
accelerated ageing and a moderate increase of
formic acid for unmodified specimens (sample A)
may be seen.
In the modified samples (subjected to both
modifications), an increase in the content of
carboxylic acids was observed, comparatively
with samples A. This increase is evidently higher
for the samples submitted to ageing with the
modification by the MgO and MMMC mixture.
Let us assume that this increase in the contents of
carboxylic acids was due to a higher amount of
MgO present in paper, than in the case of the
modification with the MgO and MMMC mixture,
but thereby these compounds of magnesium are,
in the case of the MgO and MMMC mixture,
dispersed homogenously on the paper surface and
within the paper structure. The effect of
magnesium or of its compounds on paper
degradation was confirmed by several authors.65-68
The conclusion to be drawn is that magnesium or
compounds containing magnesium have a
catalytic effect on the formation of carboxylic
acids (Table 1).
Figure 2 illustrates the effect of accelerated
ageing on the acetic/formic acids ratio for
unmodified specimens (samples A), as well as for
the specimens modified by the dispersion of MgO
(samples B) and of the MgO-MMMC mixture
(samples C). On the basis of carboxylic acids
ratio, it can be seen, that during accelerated
ageing, in unmodified samples with prolonged
ageing, the concentration ratio of acetic acid to
formic acid increases. After 30 days, the
acetic/formic acids ratio was of 3.98, the value
recorded after 60 days being of 5.52. For both
modifications, the effect of the modification
processes on the change in the ratio of carboxylic
acids during accelerated ageing at 98 °C and 50%
RH can be observed. It was found that when the
dispersion of MgO was applied, the acetic acid to
formic acid ratio varied between 1.75-3.83. In
case of the 30-day accelerated ageing, the ratio of
carboxylic acids was of 2.29. In the samples
modified by the MgO and MMMC mixture
(samples C), a decrease in the ratio of carboxylic
acids can be seen when prolonging accelerated
ageing, the value recorded after 30 days being of
1.45.
Table 1
Concentration of carboxylic acids in paper
Formic acid (mg/g) Acetic acid (mg/g)Accelerated
ageing
(days)
Samples A
(Control)
Samples B
(MgO)
Samples C
(MgO + MMMC)
Samples A
(Control)
Samples B
(MgO)
Samples C
(MgO+ MMMC)
0 0.1850.070 0.3700.019 0.4820.020 0.3610.012 0.6490.025 2.2300.085
1 0.5500.015 0.5350.020 0.7060.022 0.8920.025 1.3010.052 5.8230.189
2 0.5720.019 - - 0.8140.021 - -
3 0.4770.010 0.9050.029 1.2880.049 0.7220.023 2.3320.076 5.4530.158
5 0.8440.023 1.8960.073 3.2820.106 1.5990.050 5.5310.180 9.7550.308
7 0.8290.023 1.2630.050 - 1.3820.038 4.8400.181 -
10 0.7460.019 0.9840.035 1.8090.074 1.4690.039 2.0380.063 2.8420.090
15 0.7860.020 - 2.2130.082 2.6760.058 - 4.0970.131
20 0.4420.013 1.2910.039 1.4070.047 2.1580.057 2.5710.084 4.1790.124
30 0.7060.020 1.1140.038 3.2930.113 2.8070.074 2.5540.080 4.7270.145
60 0.8680.024 - - 4.7980.118 - -
n = 3, RSD <4%
HPLC conditions: see EXPERIMENTAL
5. Paper ageing
335
Figure 1: Influence of accelerated ageing at 98 °C and
50% RH on cold extract pH – (■) Sample A: control
specimens, (Δ) Sample B: deacidified by dispersion of
MgO, (○) Sample C: deacidified by mixture of
MgO+MMMC (3:1)
Figure 2: Influence of accelerated ageing at 98 °C and
50% RH on ratio of acetic/formic acids – (■) Sample
A: control specimens, (Δ) Sample B: deacidified by
dispersion of MgO, (○) Sample C: deacidified by
mixture of MgO+MMMC (3:1)
Figure 3: Two possible reaction pathways for oxidation of carbohydrate end-groups by oxygen in a mildly
alkaline environment (R denotes the rest of a monosaccharide)40
The content of carboxylic acids in the
modified specimens increased with prolonged
ageing, as well as in the unmodified ones. On the
basis of the measurement, it was noted that during
accelerated ageing carried out on modified
samples, a considerable increase in the
concentration of acetic acid and formic acid
occurred. These results suggest that the effect of
modification with different contents of Mg2+
was
an increased formation of carboxylic acids during
accelerated ageing. The reason for this behaviour
might be the strong promoting role of Mg2+
in
increasing the concentration of acetic and formic
acids in situ, during accelerated ageing at 98 °C
and 50% RH.
The increased content of carboxylic acids
during accelerated ageing may be due to an
alkaline pH, since, in a cellulose macromolecule,
probably only the aldehyde end-groups are
capable of spontaneous reactions with oxygen,
which are promoted by alkalinity. The mechanism
of carbohydrate oxidation in an alkaline medium
was reviewed69
by Arts et al. (1997) and the
reaction scheme presented in Figure 3 was
proposed.69,70
As known, the rate of paper degradation and
thus the amount of resulting degradation products
depend on several factors, including the initial
lignin content, type of fibres, content of metal
ions, chiefly Al, Cu, Fe and others, the moisture
content, acidity, as well as the manufacturing,
storage and accelerated ageing conditions
(temperature, relative humidity, stack or free hung
sheets, exposure to light, etc.).71
According to Zou
et al., 24
the loss of fibre strength is, in turn, due to
cellulose depolymerisation, caused by acid-
catalysed hydrolysis. These authors published in
1996 different results. It is unlikely that such an
increase in acidity would have a significant effect
on the rate of cellulose hydrolysis within the
paper. Kinetic data published by Zou et al.72
indicate that, for papers with a pH value above
4.5, the contribution of acid catalysis to the rate of
cellulose depolymerisation by hydrolysis is only
minor. But, according to recently performed
studies,49,50
acid hydrolysis causes chain scission
6. MICHAL JABLONSKY et al.
336
of cellulose macromolecules and generates
carbohydrates fragments. These fragments are
oxidised to carboxylic acids, which generate an
oxidation and hydrolysis cycle, thus enhancing
paper acidity and causing autocatalytic paper
degradation. This hypothesis would partially
explain the concentrations of weak acids, such as
formic, acetic, lactic, glycolic, oxalic, succinic,
detected in naturally aged papers. The formation
of these acids was also confirmed by other
works.34,36
Their mechanism of formation has not
been determined in detail, but they are considered
as products of the combined action of hydrolysis
and oxidation.34
The acidic products formed
during accelerated ageing accumulate inside the
paper and in the inter-sheet spaces of books or
archival files, causing enhanced degradation.73
In
stabilisation studies, it is important to realise that,
by reducing the carbonyls, we may greatly reduce
the rate of degradation. The removal of carbonyl
groups, from which enediols are formed, may
cause paper stabilisation.67
It is also evident that,
during accelerated ageing, organic acids are
formed, and may easily migrate in the loose-sheet
materials. Accelerated ageing in stacks has been
shown to increase the formation of organic acids.
The presence of Mg2+
ions is evident from the
increase in acetic and formic acids concentration,
which is not relevant for unmodified samples.
In the presence of an acid (i.e. proton-donating
ions H3O+
, notation equivalent to H+
), the
glycosidic bond is hydrolyzed and the
macromolecules split into two shorter units.73
Usually, the chemical reaction involves some
elementary steps. In the first step, the addition of
proton takes place, while later on it is removed
from the reaction products acting as a catalyst.73,4
The degradation of polysaccharides occurs in
two ways: random depolymerisation (a) and
endwise peeling (b) (Fig. 4).
Since polysaccharides can be considered
polycondensation products, their degradation, the
reverse process, involves the hydrolysis of
glycosidic bonds. The process occurs randomly
along the chains and ideally results in the
formation of monosaccharides.74
Alkaline
hydrolysis causes chain scission of the polymer
chain and decreases the average chain length
dramatically. Peeling removes one monomer unit
at a time from the reducing end of the molecule.75
This reaction does not influence the molar mass to
any appreciable extent, unless very long
processing times are used. Instead, the peeling
reaction mainly influences the carbohydrate
yields.76
The properties of the cellulose chains
determine the properties of cellulose fibres. The
decrease in the polymerization degree of cellulose
lowers the mechanical resistance of fibres,
making them susceptible to shortening, as due to
mechanical treatment.77
The addition of a Mg alkaline reserve has a
manifold effect on the degradation mechanism –
both curing and detrimental. On the one hand, it
suppresses the self-acidification of paper
produced during natural ageing, while, on the
other hand, it accelerates the formation of acids.
These are two competitive reactions. Also, paper
alkalinization induces and endwise peeling
reaction, providing substrates for acetic acid
formation; however, it should have little effect on
the overall depolymerization of the cellulose
chains. The random alkaline degradation of
polysaccharides is accompanied by the so-called
peeling reaction of the terminal saccharide units.
When subjected to strong bases, the cellulose
chain ends can react and undergo the
depolymerization reaction. This reaction explains
the detrimental effect of excessively strong bases,
such as calcium hydroxide particles, on paper
permanence. When exposed to air, they are
rapidly transformed into the corresponding
carbonates, which do not induce this
depolymerization reaction any more.78
To determine the course and result of alkaline
degradation in polysaccharides, it is importnant to
know the structural type of the saccharinic acid
that is peeled off. If, for example, the terminal
unit of the polysaccharide is lost as an
isosaccharinic or saccharinic acid, the reducing
terminal sugar unit of the polysaccharide will be
re-established. If, however, a meta-saccharinic
acid is formed at the end of the polysaccharide
chain, degradation is stopped. If β-alcoxy
elimination at C3 of the terminal unit of the
polysaccharide proceeds, the reaction does not
result in the loss of the terminal sugar unit;
instead, this unit is stabilized in the form of meta-
saccharinic acid.75
Jablonský et al.79,80
found out that a substantial
decrease (by 29.3%) in the degree of
polymerization (DP) occurred even during a 24-h
ageing, compared to the original control sample.
A decrease by 71.6% (DP = 239) was observed
after 720 h (30 days). The application of MgO
dispersion as a deacidification agent slowed down
process of degradation. After 720 h of artificial
ageing, DP was equal to 415, which means a
decrease of about 50.2%, compared to the sample
7. Paper ageing
337
deacidified by MgO during time t = 0 h. When
treating samples with a mixture of MgO and
MMMC, better results were obtained. After 30
days, DP was reduced by 29.2%, (DP = 550),
which represents a decrease by 34.6% vs. the non-
treated original sample.
Figure 4: Two models of degradation of polysaccharides: a – statistically controlled, b – endwise peeling
Based on these results, we can say that the
paper alkalisation increases the production of
acetic and formic acids, as well as the content of
magnesium salts of these acids in the modified
paper. If Mg penetrates deeper into the structure
of paper, then acid formation is more significant,
as happened for samples C, compared to samples
B.
On the other hand, despite an increase in acid
production, a substantial reduction was observed
in the degradation of modified samples. This
suggests that the effect of Mg alkalisation is
achieved by changing the extent of paper
degradation. There is mainly peeling reaction and
the mostly reaction secession of the end unit
polysaccharide in the form isosaccharinic acid. In
this way, smaller chain degradation of cellulose is
achieved. Otherwise, the production of acids
rises, rather than increasing the content of the
acetate and formate in the paper.
Despite its inaccuracy, the use of folding
endurance is widespread in paper permanence
testing, because it is very sensitive to paper
ageing.81,82
It is very sensitive to ageing,
compared to other mechanical or chemical
properties.83
The loss of folding strength (MIT
double folds, load 0.3 kg) under accelerated
ageing at 98 °C and 50% RH for unmodified
paper (samples A) and for papers modified by
MgO dispersion (samples B) and by MgO and
methyl-methoxymagnesium carbonate (MMMC)
mixture (3:1) dispersion (samples C) is shown in
Figure 5.
Accelerated ageing lasting for more than 10
days causes folding strength (MD) to decrease
considerably (the decrease in MIT double fold
number amounts to 100%). After 7 days of
accelerated ageing, the loss of strength was of
about 89% (187 MIT double folds for 7 days)
against unaged samples. After 10 days of
accelerated ageing, the sheets presented 8 MIT
double folds and the prolonged ageing decreased
the number of MIT double folds to 1. The
samples aged for more than 15 days showed small
differences. In measuring the physical properties
of weak papers, fold endurance is a definite
disadvantage.26
The decrease in folding endurance
during accelerated ageing indicates that the
groundwood newsprint paper becomes somewhat
brittle.84
8. MICHAL JABLONSKY et al.
338
Figure 5: Decrease of folding endurance (MIT double folds) through accelerated ageing at 98 °C and 50% RH – (■)
Samples A: control specimens, (Δ) samples B: deacidified by MgO dispersion, (○) samples C: deacidified by
MgO+MMMC mixture (3:1)
Despite the fact that the modification of the
paper samples by applying dispersion of MgO
and of MgO and MMMC caused an increase in
the content of carboxylic acids, it also achieved
an increase in the mechanical properties of
modified paper, compared to those of unmodified
samples A. After the modification by MgO
dispersion, the contents of acids amounted to
1.019 mg/g paper (0.37 mg formic acid/g paper
and 0.649 mg acetic acid/g paper). The folding
endurance was equal to 1885 for accelerated
ageing of 0 days at 98 °C and 50% RH. The use
of modified MgO had a positive effect on the
increase of the folding endurance, compares to
unmodified samples, where the MIT double fold
= 1672. The positive influence of the modification
by MgO and MMMC mixture was also verified
(MIT double fold = 1884). Figure 5 shows that
the loss of folding endurance during accelerated
ageing at 98 °C and 50% RH depends on the
influence of particular modifications. In the case
of paper modified by the MgO and MMMC
mixture, a smaller decrease of folding endurance
during accelerated ageing was observed,
compared to the samples modified by MgO
dispersion. In both modifications, the lack of
fibre brittleness expresses higher folding
endurance, compared to unmodified samples.
After 30 days of accelerated ageing, the increase
of the loss of folding endurance at modification of
dispersion of MgO 286 times against unmodified
paper occurred. Samples C (modified by MgO
and MMMC mixture), after 30 days of ageing,
presented 2.14 times higher folding endurance
than the samples modified by MgO dispersion.
The analysis of sheet properties indicates that the
loss of folding endurance is by far lower for the
papers submitted to each of the two
modifications, compared to unmodified paper,
despite the fact that both modifications increased
the content of acetic and formic acids.
CONCLUSIONS
The following can be concluded for
accelerated ageing, at a temperature of 98 °C and
50% RH, of unmodified paper and paper modified
by dispersion of MgO and MgO and MMMC
mixture.
The direct determination of the concentration
of carboxylic acids in situ shows increased
contents of acetic and formic acids during
accelerated ageing.
The increased content of the Mg2+
ions in the
paper structure leads to increased contents of
acetic and formic acids (respectively, acetate
and formate) during accelerated ageing, in
comparison with unmodified papers. The
reason for this behaviour might be the strong
promoting role of Mg2+
ions in the formation
of organic acids.
With the increase of the content of Mg2+
ions,
the ratio of acetic/formic acids decreases in
modified samples, compared to unmodified
papers.
The analysis of sheet properties indicates that
the loss of folding endurance is by far less
significant in papers submitted to both
modifications, compared to unmodified paper,
despite the fact that both modifications
increased the contents of acetic and formic
acids.
9. Paper ageing
339
ACKNOWLEDGEMENTS: This study was
carried out due to the financing obtained through
the projects: ME SR No 2003 c. 661/2003:
“Preservation, Stabilization and Conservation of
Traditional Information Supports in the Slovak
Republic”, APVT Project No. APVT-20-034202:
“The Deterioration of Historical Manuscripts and
Documents Related to Transitional Elements in
Writing Inks”, APVT Project No. 0324-10:
“Methods of Spectroscopy Investigation of
Documents as a Tool of Forensic Assessment”,
and VEGA Project No. 1/0811/11: “Study of
Effects of Exogenous Factors on Stability of
Colour Layers of Graphical Objects of Cultural
Heritage for its Financial Support”.
REFERENCES
1
M. Strlic, J. Kolar and S. Scholten, in “Ageing and
stabilisation of paper”, edited by M. Strlic, J. Kolar,
National and University Library, 2005, pp. 3-8.
2
V. Bukovsky and I. Kuka, Restaurator, 22, 208
(2001).
3
J. Dufour and J. B. G. A. Havermans, Restaurator,
22, 20 (2001).
4
E. Robotti, M. Bobba, A. Panepinto and E. Marengo,
Anal. Bioanal. Chem., 388, 1249 (2007).
5
J. Rychly, L. Matisova-Rychla, V. Bukovsky, M.
Pletenikova and M. Vrska, Macromol. Symp., 231, 178
(2006).
6
S. Zervos and A. Moropoulou, Cellulose, 12, 485
(2005).
7
S. Zervos and A. Moropoulou, Restaurator, 27, 219
(2006).
8
J. Kolar, Restaurator, 18, 163 (1997).
9
J. Hanus, J. Rychly, J. Minarikova et al., Procs.
International Conference on Durability of Paper and
Writing, Ljubljana, November 16-19, 2004, pp. 22-23.
10
B. Havlinova, J. Minarikova, J. Hanus, V.
Jancovicova and Z. Szaboova, Restaurator, 28, 112
(2007).
11
M. Jablonsky, M. Vrska, S. Katuscak and S. Suty,
Chemicke Listy, S(99), 571 (2005).
12
M. L. Sinnott, Chem. Rev., 90, 1171 (1990).
13
B. F. Zerek, Notes Konserwatorski, 10, 279 (2006).
14
M. S. Rakotonirainy, A. L. Dupont, B. Lavedrine, S.
Ipert and H. Cheradame, J. Cult. Herit., 9, 54 (2008).
15
W. J. Barrow and R. C. Sproull, Science, 129, 1075
(1959).
16
N. Gurnagul, R. C. Howard and X. Zou, J. Pulp Pap.
Sci., 19, J160 (1993).
17
S. R. Middleton, A. M. Scallan, X. Zou and D. H.
Page, Tappi J., 79, 187 (1996).
18
J. Unsworth and F Mitchell, IEEE Trans. Electr.
Insul., 25, 737 (1990).
19
M. Bayer, A. Lind, H. Koch and K. Fischer, J. Pulp
Pap. Sci., 25, 47 (1999).
20
S. Margutti, G. Conio, P. Calvini and E. Pedemonte,
Restaurator, 22, 67 (2001).
21
J. Malesic, J. Kolar and M. Strlic, Procs.
International Conference on Chemical Technology
Wood, Pulp Paper, edited by G. Baudin, J. Fellegi, G.
Gellerstedt, S. Katuscak, I. Pikulik, J. Paris, Slovak
University of Technology, 2003, pp. 382-384.
22
M. Strlic, V. S. Selih and J. Kolar, Procs.
International Conference on Chemical Technology
Wood, Pulp Paper, edited by G. Baudin, J. Fellegi, G.
Gellerstedt, S. Katuscak, I. Pikulik, J. Paris, Slovak
University of Technology, 2003, pp. 385-392.
23
M. Trnkova and V. Bukovsky, Procs. International
Conference on Chemical Technology Wood, Pulp
Paper, edited by G. Baudin, J. Fellegi, G. Gellerstedt,
S. Katuscak, I. Pikulik, J. Paris, Slovak University of
Technology, 2003, pp. 444-449.
24
A. L. Dupont, J. Chromatogr., 950, 113 (2002).
25
X. Zou, N. Gurnagul, T. Vesaka and J. Bouchard,
Polym. Degrad. Stabil., 43, 393 (1994).
26
J. Dolenc, B. Sket and M. Strlic, Tetrahedron Lett.,
43, 5669 (2002).
27
C. L. Arthur and J. Pawliszyn, Anal. Chem., 62,
2145 (1990).
28
C. L. Arthur, L. M. Killam, S. Motlagh et al.,
Environ. Sci. Technol., 26, 979 (1992).
29
C. L. Arthur, D. W. Potter, K. D. Buchholz, S.
Motlagh and J. Pawliszyn, LC–GC, 10, 656 (1992).
30
A. A. Boyd-Boland, M. Chai, Y. Z. Lou, Z. Zhang,
M. J. Yang, J. Pawliszyn and T. Górecki, Environ. Sci.
Technol., 28, 569S (1994).
31
Z. Zhang, M. J. Yang and J. Pawliszyn, Anal. Chem.,
66, 844A (1994).
32
T. Doering, P. Fischer, U. Binder, J. Liers and G.
Banik, in “Advances in Printing Science &
Technology”, edited by J. A. Bristol, Pira, 2001, pp.
27-39.
33
F. J. Ligterink and J. L. Pedersoli Jr., in “Book of
abstracts of the ICOM-CC Interim Meeting Working
Group on Graphic Documents”, EVTEK Institute of
Arts and Design, 2001, p. 10.
34
A. Lattuati-Derieux, S. Bonnassies-Termes and B.
Lavédrine, J. Chromatogr., A, 1026, 9 (2004).
35
A. Lattuati-Derieux, S. Bonnassies-Termes and B.
Lavédrine, J. Cult. Herit., 7, 123 (2006).
36
A.-L. Dupont, V. Egasse, A. Morin and F. Vasseur,
Carbohydr. Polym., 68, 1 (2007).
37
M. Strlic, I. Kralj Cigic, J. Kolar, G. de Bruin and B.
Pihlar, Sensors, 7, 3136 (2007).
38
S. Hobaica, in “Advances in Paper Conservation
Research”, edited by C. V. Horie, The British Library,
2009, pp. 48-50.
39
J. Hrivňák, P. Tölgyessy, S. Figedyová and S.
Katuscak, Chromatographia, 70, 619 (2009).
40
J. Hrivňák, P. Tölgyessy, S. Figedyová and S.
Katuscak, Talanta J., 80, 400 (2009).
41
M. Strlic, J. Thomas, T. Trafela, et al., Anal. Chem.,
81, 8617 (2009).
10. MICHAL JABLONSKY et al.
340
42
M. Gaspar, J. C. Santana, J. F. Lopes and M. Diniz,
Anal. Bioanal. Chem., 397, 369 (2010).
43
T. Łojewski, T. Sawoszczuk, J. M. Łagan, K. Zieba,
A. Baranski and J. Łojewska, Appl. Phys. A, 100, 873
(2010).
44
A. J. Clark, J. L. Calvillo, M. S. Roosa, D. B. Green
and J. A. Ganske, Anal. Bioanal. Chem., 399, 3589
(2011).
45
M. Strlic, I. Kralj Cigic, A. Moyir, G. de Bruinc, J.
Kolar and M. Cassara, Polym. Degrad. Stabil., 96, 608
(2011).
46
C. J. Shahani, Accelerated Aging of Paper: Can It
Really Foretell the Permanence of Paper, Preservation
Research and Testing Series No.9503, Philadelphia,
PA, November 1995, URL:
http://www.loc.gov/preserv/rt/age/age.html.
47
I. Frojd, in “Preservation Research and
Development: Round Table Proceedings”, Library of
Congress, 1992, pp. 110-117.
48
E. J. Parks and R. L. Herbert, in “BS Report 10627,
NTIS Com 75 10164”, U.S. Department of Commerce,
National Bureau of Standards, 1971a, p. 42.
49
C. J. Shahani and G. Harrison, in “Works of Art on
Paper, Books, Documents and Photographs:
Techniques and Conservation”, edited by V. Daniels,
V. A. Donnithorne, P. Smith, IIC, 2002, pp. 189-192.
50
C. J. Shahani, F. H. Hengemihle and N. Weberg,
ACS Symposium Series 410, Historic Textiles and
Paper Materials II: Conservation and Characterization,
edited by H. Zeronian, H. L. Needles, American
Chemical Society, 1989, pp. 63-80.
51
C. J. Shahani, in “ASTM Workshop on the Effects
of Aging on Printing and Writing Papers”, ASTM,
1994, pp. 120-139.
52
E. J. Parks and R. L. Herbert, in “NBS Report
10628, NTIS Com 75 10165”, U.S. Department of
Commerce, National Bureau of Standards, 1971b, p.
68.
53
J.-L. Bigourdan, P. Z. Adelstein, J. M. Reilly and J.
Bridgland, in 11th
Triennial Meeting, Edinburgh,
September 1-6, 1996, pp. 573-579.
54
M. Cedzova, M. Vrska and G. Szeiffova, Chemické
listy, 99(S), 442 (2005).
55
M. Cedzova, I. Gallova and S. Katuscak,
Restaurator, 27, 35 (2006).
56
M. Cedzova and S. Katuscak, Papir a Celulóza, 61,
10 (2006).
57
A. Lienardy and P. van Damme, Restaurator, 11, 1
(1990).
58
J. Kolar and G. Novak, Restaurator, 17, 25 (1996).
59
H. Bansa, Restaurator, 19, 1 (1998).
60
M. Strlic, D. Kocar, J. Kolar, J. Rychly and B.
Pihlar, Carbohydr. Polym., 54, 221 (2003).
61
M. Strlic, J. Kolar, D. Kocar, T. Drnovsek, V. S.
Selih, R. Susic and B. Pihlar, e-PS, 1, 25 (2004).
62
L. Bielikova, Diploma Thesis, Bratislava, Faculty of
Chemical and Food Technology, STU, 2005.
63
K. B. Hendriks, in “Environment et conservation de
l'ecrit, de l'image et du son”, ARSAG, 1994, pp. 131-
137.
64
G. Banik, Restaurator, 26, 63 (2005).
65
M. Strlic, J. Kolar, B. Pihlar, J. Rychly and L.
Matisova-Rychla, Polym. Degrad. Stabil., 72, 157
(2001).
66
M. Strlic, J. Rychly, O. Haillant, D. Kocar and J.
Kolar, in “Ageing and Stabilisation of Paper”, edited
by M. Strlic, J. Kolar, National and University Library,
2005b, pp. 133-148.
67
J. Kolar, M. Strlic, J. Malesic, J. Lemaire and D.
Fromageot, in “Ageing and Stabilisation of Paper”,
edited by M. Strlic, J. Kolar, National and University
Library, 2005, pp. 149-162
68
S. Fukuzumi, K. Ohkubo, H. Imahori and D. M.
Guldi, Chem. Eur. J., 9, 1585 (2003).
69
S. J. H. F. Arts, E. J. M. Mombarg, H. van Bekkum
and R. A Sheldon, Synthesis, 6, 597 (1997).
70
P. J. Thornalley and A. Stern, Carbohydr. Res., 134,
191 (1984).
71
P. L. Bégin and E. Kaminska, Restaurator, 23, 89
(2002).
72
X. Zou, T. Uesaka and N. Gurnagul, Cellulose, 3,
269 (1996).
73
A. Baranski, J. M. Lagan and T. Lojewski, in
“Ageing and Stabilisation of Paper”, edited by M.
Strlic, J. Kolar, National and University Library, 2005,
pp. 93-108.
74
D. Klemm, B. Philipp, T. Heinze, U. Heinze and W.
Wagenknecht, in “Comprehensive Cellulose
Chemistry”, Vol. 1, WILEY-VCH, 1998, pp. 83-124
75
A. Blazej and M. Kosik, in “Phytomas a Raw
Material for Chemistry and Biotechnology“, edited by
T. P. Neveell, Ellis Horwood, 1993, pp. 61-163.
76
R. Berggren, U. Molin, F. Berthold, H. Lennholm
and M. Lindström, Carbohydr. Polym., 51, 255 2003).
77
T. Sawoszczuk, P. Wandelt, A. Baranski, J. M.
Lagan, T. Lojewski and K. Perlinska-Sipa, in Procs.
International Conference on Durability of Paper and
Writing, edited by J. Kollar, M. Strlic, J. B. G. A.
Havermans, National and University Library, 2004, pp.
78-80.
78
M. C. Area and H. Cheradame, Bioresources, 6,
5307 (2011).
79
M. Jablonsky, F. Kacik, J. Kazikova, I. Cabalova
and J. Sivak, Acta Facultatis Xylologiae, 3, 63 (2011).
80
M. Jablonsky, J. Kazikova and S. Holubkova,
Cellulose Chem. Technol., accepted 2012.
81
C. J. Stadig and R. Hildering, Restaurator, 23, 18
(1993).
82
J. Hanus, Alkaline Paper Advocate, 9, 5 (1996).
83
B. L. Browning, in “Preservation of Paper and
Textiles of Historic and Artistic Value”, (Advances in
Chemistry Series 164), edited by J. C. Williams,
American Chemical Society, 1997, pp. 275-285.
84
M. Cernic Letnar and V. Kropar Vancina,
Restaurator, 23, 118 (2002).