Eco friendly dyeing of viscose fabric with reactive dyes


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Eco friendly dyeing of viscose fabric with reactive dyes

  1. 1. International Journal of Advanced Research in and Technology (IJARET) International Journal of Advanced Research in Engineering Engineeringand Technology (IJARET), ISSN 0976 – 6480(Print)ISSN 0976 – 6499(Online) Volume 1 IJARET ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, May - June (2010), © IAEMENumber 1, May - June (2010), pp. 25-37 © IAEME© IAEME, ECO-FRIENDLY DYEING OF VISCOSE FABRIC WITH REACTIVE DYES B. J. Agarwal Department of Textile Chemistry Faculty of Technology and Engineering The Maharaja Sayajirao University of Baroda, Vadodara E-Mail: bjagarwal@yahoo.comABSTRACT Water-soluble polymers have versatile applications but they are hardly used inwet processing of cellulosic substrates (cotton, viscose, jute, etc.), particularly in dyeing.In this paper, one such water-soluble polymer, polyacrylic acid has been synthesized,characterized and applied to viscose fabric in conjunction with various types of reactivedyes, namely triazinyl, vinyl sulphone, high exhaustion and bi-functional, along withcross-linking agents, namely Glycerol-1,3-dichlorohydrin and hexamethylene tetramine-hydroquinone respectively. One of the cross-linking agents (the former one) has beensynthesized in the laboratory and characterized. Cross-linking agent is necessary toadhere the dye onto the cellulose macromolecule. Different process sequences have beenformulated for dyeing purpose. The dyed samples were assessed by Computer ColourMatching system for colour strength in terms of K/S values and their fastness propertieswere assessed by standard methods. All such dyeings were compared with conventionaldyed samples.Key words: Polyacrylic acid, cross-linking agent, viscose, reactive dyes1. INTRODUCTION In the textile industry, ecology and economy are the two most important aspectsin the present worldwide scenario and their significance is of great importance for thesurvival of the textile industry. There is an increasing demand for the minimization ofpollution load during wet processing of textiles, particularly in dyeing. 25
  2. 2. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, May - June (2010), © IAEME For dyeing of cellulosic substrates, the most widely used dyes are Reactive dyes.Their popularity on the commercial scale is mainly due to their acceptable price,brilliancy of shades, good tinctorial value and reasonably good fastness properties.However, they suffer from several drawbacks – one of which is environmental hazardsdue to the utilization of very high concentrations of exhausting agents, viz. sodiumchloride or sodium sulphate (up to 100 gpl) as well as alkali (up to 20 gpl) in its dyeingprocess, which ultimately cause tremendous effluent problems. Together with this,commercial reactive dyes give only 65-70% exhaustion of the dyebath liquor. Further, toremove the unfixed dye, time-consuming, energy intensive and expensive washing-offprocedures are required. Unfixed reactive dye and/or hydrolyzed dye, along with alkali used for fixation,may also pose an environmental hazard because the hydrolyzed dye will pass in theeffluent thereby increasing the pollution load. Certain reactive dyes, like mono- and di-chlorotriazine, or flourotriazine type of reactive dyes may cause the passage of organo-halogen in the discharge effluent, which may by-pass the permissible discharge limitfixed by certain countries. The achievement of high dye fixation in a non-polluting dyeing procedure wouldbe of great benefit. This can be attained either by the modification of the dyeingprocedure or the substrate itself, or by the development of dyes with high fixation yields. Treatment of cotton, viscose and other cellulosic substrates with variouschemicals prior to its dyeing has been reported in literature to improve their dyeabilitywith reactive dyes [1-4]. Dyeing of such pretreated fabric(s) was followed by treatmentwith an alkali for the fixation of these dyes. Other approaches reported [5-11] wheresome chemicals have been devised, namely Glytac A, etc. for improving the dyeability ofsuch cellulosic materials with reactive dyes, which is due to increased dyebathexhaustion. In all these cases, alkaline conditions have been used for dyeing. In spite ofextensive search, very little information has been received for dyeing cotton, viscose, etc.with reactive dyes at neutral pH. Burkinshaw et. al. [12-13] recently reported a method ofdyeing cotton using Hercosett resin pretreatments, thereby improving the substantivityand reactivity of cotton. This facilitates dyeing process at neutral pH but lowers the lightfastness. Thus, it would be a great achievement if reactive dyes can be applied to 26
  3. 3. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, May - June (2010), © IAEMEcellulosic substrates without utilization of any alkali or salt in the dyebath. In this paper,an attempt has been made to study the modification of viscose material in order toperform reactive dyeing even at neutral pH conditions, i.e. without utilizing salt, alkali orany other chemical in the dyebath. For this purpose, a treatment with a highly reactivepolymer has been suggested.2. MATERIALS & EXPERIMENTAL PROCEDURES2.1 Materials Plain weave viscose fabric (prepared from high twist yarn without lustre), havingfollowing specifications, was used for the study: Warp: 98 ends/inch Weft: 64picks/inch Weight: 94 g/m2 The fabric was scoured with 5 gpl non-ionic detergent (Lissapol N) and 5 gpl sodaash at boil for 90 min. The scoured fabric was then bleached with sodium hypochlorite (3gpl available chlorine) using pH 10 at room temperature for 1 hour and subsequentlywashed thoroughly till it became neutral. Acrylic acid monomer (A. R. grade) was used for the present investigation. Twocross-linking agents, namely Glycerol-1,3-dichlorohydrin (CA) and hexamethylenetetramine-hydroquinone (CB) utilized were based on non-nitrogenous and nitrogenoustype products respectively. The former cross-linking agent, Glycerol-1, 3-dichlorohydrinhas been synthesized in the laboratory. For the synthesis, Epichlorohydrin (mol. wt. 92.53and purity 98%) and other chemicals used were of laboratory grade. Hexamethylenetetramine-hydroquinone (HMTA-HQ) cross-linking agent used was of AnalyticalReagent grade. Ten commercial reactive dyes, comprising of various reactive systems, viz.monochlorotriazine (MCT), dichlorotriazine (DCT), vinyl sulphone (VS), bis-monochlorotriazine (high exhaustion, HE) and bifunctional (ME) dyes were used withoutany further purification. The reactive dyes used for the work are represented in Table 1. 27
  4. 4. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, May - June (2010), © IAEME Table 1Reactive dyes used with their reactive systems and Colour Index numbers DYE CI Reactive Monochloro-triazine (MCT) dye D1 Procion Brill. Red H7B Red 4 D2 Procion Blue H5R Blue 13 Dichlorotriazine (DCT) dye D3 Procion Brilliant Red M5B Red 2 D4 Procion Brilliant Yellow MGR Yellow 7 Vinyl Sulphone (VS) dye D5 Remazol Brilliant Violet 5R Violet 5 D6 Remazol Brilliant Red 3B Red 23 High Exhaustion (HE) Reactive dye D7 Procion Red HE-3B Red 120 D8 Procion Orange HE-R Orange 84 Bifunctional (ME) Reactive dyes Red 195 D9 Reactofix Red ME4BL D10 Reactofix Blue ME2RL Blue 2482.2 Methods2.2.1 Polymer preparation Polyacrylic acid was synthesized from its monomer acrylic acid by standardpolymerization process. The polymer thus formed was with viscosity average molecularweight 3,416 and the solid content of the synthesized polymer was 48%.2.2.2 Preparation of Glycerol-1,3-dichlorohydrin Glycerol-1,3-dichlorohydrin was prepared by interaction of Epichlorohydrin andHydrochloric acid. Epichlorohydrin was gradually added to a mixture of 1 part conc. HCland 3 parts of 13% by weight NaCl solution at 30o C over a period of 2 hours.2.2.3 Pretreatment Viscose fabric was treated in liquor containing polyacrylic acid (50 gpl) andcross-linking agent (25 gpl) and then immediately padded (to minimize the reactionbetween polyacrylic acid and the individual cross-linking agent) by 2-dip-2-nip technique(using 65% expression). After padding, the fabric was dried at an ambient temperature 28
  5. 5. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, May - June (2010), © IAEMEand cured at 150o C for 4 min. The curing conditions were so chosen as these arecommercially practiced in wet processing of textiles, e.g. in wash-n-wear and pigmentdyeing/printing for cellulosic materials. The pretreated sample was rinsed with water anddried. The mass add-on of the polyacrylic acid-CA treated sample was found to be 6.7%and that of polyacrylic acid-CB treated sample was 8.2%. The concentrations of polyacrylic acid and each individual cross-linking agentCA and CB were optimized followed by the assessment of their dyeability (K/S values)with two commercial reactive dyes, viz. CI Reactive Red 4 (MCT) and CI Reactive Red 2(DCT) at 2% depth of shades on the pretreated samples by exhaust dyeing for 90 min atboil (for MCT dye) and at 50o C (for DCT dye), as well as by pad-dry-cure dyeing(curing conditions: 150o C/4 min for MCT dye and 150o C/1min for DCT dye)techniques. In above dyeings, no alkali/salt was used. The pH of the dyebath wasmaintained at 7.0 ± 0.1. After dyeing, the dyed sample was washed, soaped with a non-ionic detergent, Lissapol N (2 gpl) and soda ash (1 gpl) at 60o C for 30 min using a liquorratio of 30:1, followed by thorough rinsing and drying.2.2.4 Dyeing Procedures After optimization, dyeing was performed with pad-dry-cure method at differentdepth of shades, viz. 0.5, 1, 2, 3, and 5% respectively. Subsequently, different processsequences were formulated and ten commercial reactive dyes containing various reactivesystems were applied on pretreated samples at 2% shade. Various dyeing sequencesadopted were:S I – Exhaust dyeing: Pretreated sample was dyed for 90 min. at boil (for MCT, VS &HE dyes) and at 50o C (for DCT & ME dyes)S II – Pretreatment followed by pad-dry-cure dyeing: Pretreated sample was paddedwith requisite amount of dye solution using 2-dip-2-nip technique (65 % expression),dried and cured.S III – Simultaneous dyeing: Sample was padded with optimized concentrations ofpolyacrylic acid, cross-linking agent and dye, dried and cured. For sequences S II and S III, curing conditions chosen were 150o C & 4 min forMCT, VS, & HE dyes and 150o C & 1min for DCT & ME dyes, while the washing andsoaping procedures were kept same as mentioned earlier. Various dyeings were also 29
  6. 6. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, May - June (2010), © IAEMEcompared with conventionally dyed samples [14].2.3 Testing and Analysis2.3.1 Mechanical Properties Tensile properties, namely breaking strength and elongation at break, of thetreated and untreated samples were determined on the Instron 1121 tensile tester. Anaverage of 10 readings was taken.2.3.2 Determination of Nitrogen Content Nitrogen content of the treated and untreated samples was determined on C, H, NAnalyzer (Perkin Elmer Model 240 Elemental Analyzer).2.3.3 Evaluation of Colour Strength The dyeing performance of various dyed samples was assessed on Data Spectraflash SF 600 Spectrophotometer by measuring the relative colour strength (K/S value)spectrophotometrically. These values are computer calculated from reflectance dataaccording to Kubelka-Munk equation [15].2.3.4 Assessment of Fastness Properties [16] Wash fastness was evaluated according to ISO Standard Test No.3 on Launder-O-meter; light fastness on fade-O-meter using carbon-arc continuous illumination (BS 1006:1987) and rub fastness (both dry as well as wet) on Crockmeter (BS 1006: No.X12;1978).2.3.5 Determination of Wrinkle Resistance Wrinkle resistance (crease recovery) of the untreated and treated samples wasmeasured on crease recovery tester (Model: Sasmira) using standard method [16].3. RESULTS AND DISCUSSION Viscose fabric, treated with polyacrylic acid and cross-linking agent, was dyedwith reactive dyes (CI Reactive Red 4 and CI Reactive Red 2) without using alkali/salt,i.e. at neutral pH (7.0 ± 0.1). Uniform dyeing was obtained. Therefore, the concentrationsof polyacrylic acid and cross-linking agents were optimized. This was carried out byusing various concentrations of polyacrylic acid (50, 100, 150, 200 and 250 gpl) andcross-linking agent (25, 50, 75, 100 and 150 gpl) for both exhaust as well as pad-dry-curedyeing methods. Optimized concentrations of these three were found out individually by 30
  7. 7. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, May - June (2010), © IAEMEassessing the dyeing performance in terms of K/S values (not mentioned here) of therespective sample. It was found that optimum concentration of polyacrylic acid was 100gpl (for exhaust dyeing process) and 150 gpl (for pad-dry-cure process), while theoptimum concentration of cross linking agent CA was 25 gpl (for both the dyeingprocesses) and the respective values of cross-linking agent CB were 25 gpl (for exhaustdyeing) and 50 gpl (for pad-dry-cure dyeing). The morphological changes incurred in the cellulosic substrate due to suchtreatment were investigated through nitrogen content determination and tensile propertiesof the pretreated sample. The nitrogen content value of only polyacrylic acid treated (150gpl/pad-dry-cure process) sample was 0.139% and those treated along with cross-linkingagent CA or CB (50 gpl) sample were 0.214% and 0.795% respectively. This higher valueof nitrogen content, particularly in case of polyacrylic acid and cross-linking agent CBtreated sample manifests the possibility of cross-linking reaction being taken place withcellulose macromolecule. The sample pretreated with polyacrylic acid and cross-linking agent CA (atoptimized concentration) showed 14.7 kg breaking strength and 13.6% elongation-at-break. The respective values for polyacrylic acid and cross-linking agent CB treatedsample (at optimized concentration) are 13.3 kg and 14.2% as compared with 16.28 kgand 12.3% breaking strength and elongation-at-break respectively for untreated sample.The decrease in breaking strength, viz. 9.7% (in case of cross-linking agent CA) and18.3% (in case of cross-linking agent CB) is also an indicative of cross-linking reactionbeing taken place. The optimized concentrations of polyacrylic acid and the two cross-linking agenthave been used to study their various dyeing behaviour at neutral pH. It has beenobserved that pretreated fabric offered very good dyeing with pad-dry-cure dyeingtechnique as compared with exhaust dyeing. Therefore, viscose fabric was subsequentlydyed by pad-dry-cure process at different depth of shades with three reactive dyes, oneeach of MCT, DCT and VS groups. The results are represented in Table 2. It can be seenthat satisfactory dyeing is achieved on pretreated samples at all levels of dyeing. The dyeuptake increases with the increase in the concentration of the dye in the dyebath.Dichlorotriazine (DCT) based dye gave best dyeing performance followed by vinyl 31
  8. 8. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, May - June (2010), © IAEMEsulphone (VS) and monochlorotriazine (MCT) dyes. This in good agreement with theobservations reported in literature [14]. Table 2 Colour strength (in terms of K/S values) of viscose fabric dyed by pad-dry-cure (S II) technique with various percent shades using different reactive dyes Dye K/S values Dye CI conc. Conventional Polymer-aided dyeing by S II process Reactive (%) dyeing P + CA P + CAProcion Blue H5R Blue 13 0.5 2.19 1.65 (-24.65) 1.98 (-9.59)(MCT dye) 1.0 5.86 5.11 (-12.79) 5.63 (-3.92) 2.0 12.56 11.98 (-4.61) 12.15 (-3.26) 3.0 16.29 14.25 (-12.52) 15.23 (-6.50) 5.0 22.35 20.81 (-6.89) 21.96 (-1.74)Procion Brill. Red M5B Red 2 0.5 5.26 4.36 (-17.11) 5.12 (-2.66)(DCT dye) 1.0 11.51 9.88 (-14.16) 10.29 (-10.59) 2.0 19.63 18.62 (-5.14) 19.11 (-2.65) 3.0 24.96 22.15 (-11.26) 24.35 (-2.44) 5.0 32.33 29.63 (-8.35) 32.68 (+1.08)Remazol Brill. Violet 5R Violet 5 0.5 3.21 2.65 (-17.44) 3.11 (-3.11)(VS dye) 1.0 6.89 5.86 (-14.95) 7.02 (+1.88) 2.0 12.39 11.59 (-6.45) 12.98 (+4.76) 3.0 17.86 15.66 (-12.32) 18.15 (+1.62) 5.0 25.28 21.29 (-15.78) 27.26 (-7.83)Note: Data in parenthesis indicates percentage loss/gain over conventional dyeing. P - Polyacrylic acid, CA - Glycerol-1, 3-dichlorohydrin CB - Hexamethylene tetramine-hydroquinone The probable mechanism for fixation of reactive dyes on polyacrylic acid treatedand partially cross-linked viscose fabric may be explained as: Viscose fabric treated with polyacrylic acid and cross-linking agents (particularlyCB type) demonstrate the introduction of a highly nucleophilic amino group (-NH2) in thecellulosic chain. The cationic charged amino groups may be involved in the adsorption ofanionic chromophore of reactive dyes. The attachment of dye molecules onto the partiallymodified cellulosic substrate is found to be through covalent bonding as no dye strips outfrom dyed sample in pyridine (100%) as well as in its mixture with water (50:50). An attempt has been made in the present investigation to commercialize thisneutral dyeing of reactive dyes on viscose. For this, ten commercial reactive dyes,comprising of MCT, DCT, VS, bis-MCT and bifunctional groups were dyed by differentdyeing sequences as mentioned. The results are given in Table 3. Such dyeings were also 32
  9. 9. International Journal of Advanced Research in Engineering and Technology (IJARET) ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, May - June (2010), © IAEME compared with conventionally dyed sample. No clear trend is observed from the results. The nature as well as chemical constitution of the dye and the dyeing process utilized also influences the dyeing performances. Table 3 Colour strength (in terms of K/S values) of viscose fabric dyed with different reactive dyes K/S values for Polymer-aided dyeing Dye CI Exhaustion (S I) Pad-dry-cure (S II) Pad-dry-cure (S III) Reactive P + CA P + CB P+ P + CB P + CA P + CB CAMonochlorotriazinedyeD1 Procion Brill. Red Red 4 4.11 4.36 10.21 10.98(-1.34) 11.26(+1.17)11.53(-3.59)H7B (-17.47) (-12.45) (-8.26)D2 Procion Blue H5R Blue 13 3.29 3.98 11.63 12.05(-2.90) 12.12(-2.33) 13.08(-5.39) (-20.14) (-3.39) (-6.28)Dichlorotriazine dyeD3 Procion Brill. Red Red 2 4.19 4.88 12.63 15.69 19.99 25.23(+28.20)M5B (-19.73) (-6.50) (-35.82) (-20.27) (+1.57)D4 Procion Brill. Yellow 7 4.98 5.08 7.26 8.15(-4.56) 9.25(+8.31) 12.59(+47.42)Yellow MGR (-11.38) (-9.61) (-14.98)Vinyl Sulphone dyeD5 Remazol Brill. Violet 5 4.63 5.13 9.23 11.54 13.63 19.86(+62.92)Violet 5R (-11.47) (-1.91) (-25.28) (-5.33) (+11.81)D6 Remazol Brill. Red 23 4.01 4.29 11.63 13.21 14.11 25.81(+95.67)Red 3B (-5.64) (+0.94) (-11.82) (+0.15) (+6.97)High ExhaustionReactive dyeD7 Procion Red HE- Red 120 11.96 12.92 6.12 6.48 7.23(-5.12) 7.98(+4.72)3B (-6.56) (+0.93) (-19.68) (-14.96)D8 Procion Orange Orange 12.15 13.66 5.86 6.23 6.98(+7.05) 7.11(+9.05)HE-R 84 (-6.03) (+5.64) (-10.12) (-4.47)Bifunctional ReactivedyesD9 Reactofix Red Red 195 13.15 14.98 8.21 9.15 10.25 12.63ME4BL (-10.36) (+2.11) (-16.73) (-7.20) (+3.95) (+28.09)D10 Reactofix Blue Blue 248 16.28 17.26 10.33 11.36 12.15(8.19) 15.23ME2RL (-3.26) (+2.55) (-8.01) (+1.15) (+35.62) It can be observed that in case of MCT, DCT and VS dyes, the colour strength of treated sample dyed by either S I or S II are only slightly lower in comparison with the respective conventionally dyed samples. This is due to slight lower fixation of the dye in 33
  10. 10. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, May - June (2010), © IAEMEabsence of alkali in S I and S II sequences. However, sample dyed by S III sequence gavebetter dyeing performance (colour strength enhanced up to 63% and 96% with D5 and D6dyes respectively for polyacrylic acid and cross-linking agent CB, and by 1% to 48% withvarious other reactive dyes, with a few exceptions) over conventionally dyed samples.The overall dyeing performance of these three dyeing sequences with MCT, DCT, VSand ME reactive dyes can be represented as S III > S II > S I. On the other hand, areverse trend is observed with high exhaust (bis-monochlorotriazine/HE type) andbifunctional (ME type) reactive dyes for obvious reason of their high reactivity as well asthe nature of the dye. With these dyes, the observed dyeing performance is represented asS I > S III > S II. The reason for such behaviour may be attributed to the fact that in S IIIsequence, the dye molecule and cross-linking agent molecule compete with each other tocombine with either cellulosic hydroxyl group or with the groups on the polymeric chain.The reactive dye is capable of combining with hydroxyl group of cellulose via covalentbond formation, which varies from dye to dye depending upon their reactivity. Theunfixed reactive dye molecules also get linked with the polymeric chain at the curingstage. This results in increased colour strength during S III sequence. The fastness properties of all such dyed sample are quite satisfactory andcomparable with conventionally dyed sample (Table 4). However, in polymer-aidedexhaust dyeing process (S I), there is slight impairment in the light fastness for some ofthe dyes, particularly DCT dyes. Improved wrinkle recovery is expected due to occurrence of cross-linkingreactions as manifested earlier. The dry crease recovery angle (DCRA) values of thepolymer-aided dyed samples were 133o (S I), 135o (S II) and 129o (S III) for Glycerol-1,3-dichlorohydrin (CA) cross linking agent and 131o (S I), 132o (S II) and 130o (S III) forhexamethylene tetramine-hydroquinone (CB) cross-linking agent, while that of bleached(untreated) and treated (undyed) samples are 95o and 109o respectively. The DCRA forconventionally dyed sample were 115o (exhaust dyeing) and 117o (pad-dry-cure)respectively. Therefore, the polymer-aided dyed samples indicate an improvement in thewrinkle recovery for obvious reason. In sequence S III, the extent of cross-linking isrestricted because of the process involved, thereby offering comparatively less DCRAvalues. 34
  11. 11. International Journal of Advanced Research in Engineering and Technology (IJARET) ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, May - June (2010), © IAEME Table 4 Fastness properties of viscose fabric dyed with various reactive dyes Fastness grades for Polymer-aided dyeing Exhaustion (SI) Pad-dry-cure (SII) Pad-dry-cure (SIII) CI Dye Reac P + CA P + CB P + CA P + CB P + CA P + CB tive W L R WL R WL R WL R WL R W L R Dr We Dr We Dr We Dr We Dr We Dr We y t y t y t y t y t y tMonochloro-triazine dyeD1 Procion Brill. Red 4 4-5 5 5 4-5 4- 5 5 7 5 7 4 3-4 5 7 4 3-4 4 7 4-5 4-5 5 7 4-5 4-5Red H7B - 5 - 6 6D3 Procion Blue Blue 4-5 5 5 4-5 4- 5 4-5 7 4- 7 4 4 4- 7 4 4 4 7 4 4 4-5 7 4 4H5R 13 - 5 - 5 5 6 6Dichlorotriazine dyeD3 Procion Brill. Red 2 5 4 5 4-5 5 4 5 7 5 7 4 4 5 7 4 4 5 7 4-5 4-5 5 7 4-5 4-5Red M5B - - 5 5D4 Procion Brill. Yello 4-5 4 5 4-5 4- 4 4-5 6-7 4- 6 4 4 4- 6 4 4 5 7 4-5 4-5 5 7 4-5 4-5Yellow MGR w7 5 - 5 - 5 - 5 7 7Vinyl SulphonedyeD5 Remazol Viole 4-5 6 5 5 4- 6 4-5 7 5 7 4 5 4- 7 4-5 4 4- 7 4-5 4-5 4-5 7 4-5 4-5Brill. Violet 5R t 5 5 - 5 5 7D6 Remazol Red 4-5 6 5 4-5 4 6 5 7 4- 7 4 4-5 5 7 4-5 4 4- 6 4-5 4 4-5 6-7 4-5 4Brill. Red 3B 23 - 5 5 - 7 7HighExhaustionReactive dyeD7 Procion Red Red 5 7 5 5 5 7 5 7 5 7 5 4-5 5 7 5 4-5 5 7 5 4-5 5 7 5 4-5HE-3B 120D8 Procion Oran 5 7 5 5 5 7 5 7 5 7 5 4-5 5 7 5 4-5 5 7 5 4-5 5 7 5 4-5Orange HE-R ge 84BifunctionalReactive dyesD9 Reactofix Red 5 6 5 5 4- 7 5 4-5 5 6 4-5 5 5 6 4 4-5 5 6- 4 4 5 6-7 4 5Red ME4BL 195 - 5 - - 7 7 7 7D10 Reactofix Blue 4-5 6 5 4-5 4- 7 5 4-5 5 7 4 5 5 6 4-5 4 5 7 4 5 5 7 4 4Blue ME2RL 248 5 - 7 W = Washing fastness, L = Light fastness, R = Rubbing fastness. 35
  12. 12. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, May - June (2010), © IAEMEP - Polyacrylic acid, CA - Glycerol-1, 3-dichlorohydrin, CB - Hexamethylene tetramine-hydroquinoneCONCLUSIONS Viscose fabric was pretreated with polyacrylic acid and cross-linked with eitherCA or CB cross-linking agents by pad-dry-cure (at 150o C for 4 min) technique. Theoptimum concentration for polyacrylic acid was found to be 100 gpl (for exhaust dyeing)and 150 gpl (for pad-dry-cure dyeing) and that for CA cross-linking agent was 25 gpl (foreither dyeing method) and for CB cross-linking agent were 25 gpl and 50gpl respectivelyfor exhaust and pad-dry-cure dyeing techniques respectively. The morphological changesindicate cross-linking reaction through higher nitrogen content (0.214% with CA cross-linking agent and 0.795% with CB cross-linking agent), and also decrease in tensilestrength by 9.7% with CA and 18.3% with CB cross-linking agents respectively. Such pretreated and partially cross-linked viscose fabric can successfully be dyedwith various types of reactive dyes by different process sequences. The colour strength ofall the dyed samples was adequate and quite comparable with conventionally dyedsamples. The polymer (polyacrylic acid)-aided dyeing was better when hexamethylenetetramine-hydroquinone (CB) was used as the cross-linking agent as compared toGlycerol-1,3-dichlorohydrin (CA) cross linking agent. In case of simultaneous dyeing(SIII), the dye-uptake was about 1 – 96% (in case of DCT, VS and ME dyes) and up to10% (in case of MCT and HE dyes) higher with respect to their conventionally dyedsamples. The plausible dyeing mechanism revealed covalent bond formation. Thefastness properties of such dyeings were very good. The dyed fabric also exhibited veryencouraging wrinkle recovery, which may replace even the subsequent wash-n-weartreatment. The fabric so dyed did not utilize any salt or alkali during dyeing. So it may beconsidered as Green processing of textiles without any pollution problem.REFERENCES 1. D. Soignet, G. Berni and R. Benerilo (1966), Textile Research Journal, 36, pp.978. 2. A. Hebeish and M. H. El-Rafie (1990), American Dyestuff Reporter, 79(7), pp.34. 3. H. M. Hamza and H. M. El-Nabas (1991), Journal of Society of Dyers & Colourist, 107, pp.144. 36
  13. 13. International Journal of Advanced Research in Engineering and Technology (IJARET)ISSN 0976 – 6480(Print), ISSN 0976 – 6499(Online) Volume 1, Number 1, May - June (2010), © IAEME 4. G. E. Evans, J. Shore and C. V. Stead (1984), Journal of Society of Dyers & Colourist, 100, pp.304. 5. N. Bhattacharyya and P. R. Mistry (1990), American Dyestuff Reporter, 79(3), pp.24. 6. D. M. Lewis and X. P. Lei (1989), Textile Chemists & Colorist, 21, pp.23. 7. M. H. Abou-Shousha (1988), American Dyestuff Reporter, 77(10), pp.32. 8. D. M. Lewis and X. P. Lei (1991), Journal of Society of Dyers & Colourist, 107, pp.102. 9. R. J. Harper et. al. (1988), Textile Chemists & Colorist, 20, pp.25. 10. M. Sekamoto et. al. (1973), Journal of Applied Polymer Science, 17, pp.283. 11. T. L. Vigo and E. J. Blanchard (1987), Textile Chemists & Colorist, 19, pp.19. 12. S. M. Burkinshaw, X. P. Lei and D. M. Lewis (1989), Journal of Society of Dyers & Colourist, 105, pp.391. 13. S. M. Burkinshaw, X. P. Lei and D. M. Lewis (1990), Journal of Society of Dyers & Colourist, 106, pp. 307. 14. E. R. Trotman (1975), “Dyeing and Chemical Technology of Textile Fibres”, 5th Edition, Charles Griffin and Company Ltd.; London and High Wycombe, pp.540. 15. F. W. Billmeyer Jr., and M. Saltzman (1981), “Principles of Colour Technology”, 2nd Edition; John Wiley & Sons: New York; pp.140. 16. J. E. Booth (1987), “Principles of Textile Testing”, Butterworth Scientific Publishers: London. 37