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Cta2, Cellulose Acetate


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Cta2, Cellulose Acetate

  1. 1. ‫ﺧﺪﺍ‬ ‫ﻧﺎﻡ‬ ‫ﺑﻪ‬ ‫ﺳﻠﻮﻟﺰ‬ ‫ﺍﺳﺘﺎﺕ‬ ‫ﻗﺎﺳﻣﻳﺎﻥ‬ ‫ﺩﮐﺗﺭ‬ ‫ﺍﺳﺗﺎﺩ‬ Rouzbeh Asadi Khansari ‫ﺧﻭﺍﻧﺳﺎﺭی‬ ‫ﺍﺳﺩی‬ ‫ﺭﻭﺯﺑﻪ‬
  2. 2. • ‫ﻫﻴﺪﺭﻛﺴﻴﻞ‬ ‫ﺟﺎﻳﮕﺰﻳﻨﻲ‬ • ‫ﻛﻠﺮﻭﻓﺮﻡ‬ ‫ﺩﺭ‬ ‫ﻣﺤﻠﻮﻝ‬ ‫ﺳﻠﻮﻟﺰ‬ ‫ﺍﺳﺘﺎﺕ‬ • ‫ﺍﺳﺘﻦ‬ ‫ﺩﺭ‬ ‫ﻣﺤﻠﻮﻝ‬ ‫ﺳﻠﻮﻟﺰ‬ ‫ﺍﺳﺘﺎﺕ‬ • ‫ﻧﻴﺘﺮﻭﻣﺘﺎﻥ‬ ‫ﺑﺨﺎﺭ‬ ‫ﻭ‬ ‫ﺳﻠﻮﻟﺰ‬ ‫ﺍﺳﺘﺎﺕ‬ • ‫ﺳﺎﻝ‬ ‫ﺩﺭ‬ ‫ﭘﻠﻴﻤﺮﻱ‬ ‫ﻣﻨﻔﺮﺩ‬ ‫ﻛﺮﻳﺴﺘﺎﻟﻬﺎﻱ‬ ‫ﻛﺸﻒ‬1963 • ‫ﺍﻟﻜﺘﺮﻭﻧﻲ‬ ‫ﻣﻴﻜﺮﻭﺳﻜﻮپ‬ ‫ﺩﺭ‬ ‫ﭼﻬﺎﺭﮔﻮﺵ‬ ‫ﻣﻨﻔﺮﺩ‬ ‫ﻛﺮﻳﺴﺘﺎﻟﻬﺎﻱ‬ • ‫ﺍﺗﺼﺎﻝ‬ ‫ﺯﻧﺠﻴﺮﻭﺩﺭﺍﻧﺘﻬﺎ‬ ‫ﻣﻮﺍﺯﻱ‬ ‫ﻫﺎﻱ‬ ‫ﺑﺴﺘﻪ‬ ‫ﺷﺪﻥ‬ ‫ﻣﺮﺗﺐ‬ ‫ﺯﻧﺠﻴﺮﻏﻴﺮﻣﻮﺍﺯﻱ‬ • ‫ﺑﻠﻮﺭﻳﻦ‬ ‫ﺩﺭﺟﻪ‬ • ‫ﮔﺴﺘﺮﺩﻩ‬‫ﻛﺮﻳﺴﺘﺎﻟﻴﻦ‬ ‫ﺗﺮﻛﻴﺒﺎﺕ‬ ‫ﺷﻨﺎﺳﺎﻳﻲ‬ ‫ﺩﺭ‬ ‫ﺍﺳﺘﻔﺎﺩﻩ‬ ‫ﺗﺮﻳﻦ‬ XRD
  3. 3. Properties of natural & synthetic fibers
  4. 4. Cellulose Reaction of the OH group: esters, ethers, etc. DS=degree of substitution is important: DS=0-3/glucose The DS is dependent on the availability of OH groups so it is a function of the H-bonding in cellulose!
  5. 5. Reaction of Cellulose Acetate Esters commercially made by Eastman. Mostly short fibers for non-wovens like cigarette butts! Relies on acetylated OH groups -C C O- = O cellulose + acetic acid + acetic anhydride + H2SO4 partial hydrolysis dissolve in acetone and spin fiber Cellulose will react under anhydrous conditions in the presence of acid catalyst and acetic anhydride to form cellulose tri-acetate. Cellulose acetate is the partially acetylated product of high purity cellulose and acetic anhydride. It is obtained by acid catalyzed hydrolysis of the tri-acetate to a DSav~2.4 (cellulose tri-acetate would be DS~3.0) ester linkages!
  6. 6. Cellulose Acetate CH3 C O OCOCH3 CH3 C OH OCOCH3 CH3 C O OCOCH3 +H + Cell CH3 C OH OCOCH3 CH3 C O O HO Cell Cell
  7. 7. DS of Cellulose Acetate H2SO4 C-OH + (CH3CO)2O OH group on cellulose acetic anhydride C-OOCCH3 + CH3COOH cellulose tri- acetate=ester acetic acid (H from cellulose OH) acetic anhydride is split in 1/2 hydrolysis C-OOCCH3 cellulose tri- acetate=ester + 0.2H2O C-(OOCCH3)0.8 cellulose acetate=ester (OH)0.2 + 0.2CH3COOH acetic acid DS=3(0.8)=2.4/glucose can be v. high! This material is soluble in acetone and other organic solvents Properties, like biodegradability, are f(DS): remember, the biggest impediment to this rxn is the availability of OH’s from H-bonding this is fully acetylated cellulose (sulfuric acid)
  8. 8. Degree of polymerization
  9. 9. History of Cellulose acetate (zyl, zylonite,Cellon and Rhodoid) • Paul Schützenberger discovered cellulose acetate in 1865 • George Miles more solvents in 1904 • Camille and Henri Dreyfus in 1910 • DOPE • In1914,The British Cellulose and Chemical Manufacturing Co - 1918 to British Celanese Ltd • In 1918 The American Cellulose & Chemical Manufacturing Company in New York by the Dreyfus brothers In 1927- the Celanese Corporation of America • Mazzucchelli ,Celluloid Acetate sheets and Cellulose Nitrate • Cellulose acetate film was introduced in 1934 • IBM in 1952 for use on their IBM 726 tape drive in the IBM 701 computer
  10. 10. To help protect your privacy, PowerPoint prevented this external picture from being automatically downloaded. To download and display this picture, click Options in the Message Bar, and then click Enable external content. Fiber properties • Hand: soft, smooth, dry, crisp, resilient • Comfort: breathes, wicks, dries quickly, no static cling • Drape: linings move with the body linings conform to the garment • Color: deep brilliant shades with atmospheric dyeing meet colorfastness requirements • Luster: light reflection creates a signature appearance • Performance: colorfast to perspiration staining, colorfast to dry cleaning, air and vapor permeable • Tenacity: weak fiber with breaking tenacity of 1.2 to 1.4 g/d; rapidly loses strength when wet; must be dry cleaned • Abrasion: poor resistance • Heat retention: poor thermal retention; no allergenic potential (hypoallergenic) • Dyeability: (two methods) cross-dying method where yarns of one fiber and those of another fiber are woven into a fabric in a desired pattern; solution-dying method provides excellent color fastness under the effects of sunlight, perspiration, air contaminants and washing
  11. 11. To help protect your privacy, PowerPoint prevented this external picture from being automatically downloaded. To download and display this picture, click Options in the Message Bar, and then click Enable external content. Production method • Purified cellulose from wood pulp or cotton linters. • Mixed with glacial acetic acid, acetic anhydride, and a catalyst • Aged 20 hours- partial hydrolysis occurs • Precipitated as acid-resin flakes • Flakes dissolved in acetone • Solution is filtered • Spinning solution extruded in column of warm air. Solvent recovered • Filaments are stretched and wound onto beams, cones, or bobbins ready for use
  12. 12. To help protect your privacy, PowerPoint prevented this external picture from being automatically downloaded. To download and display this picture, click Options in the Message Bar, and then click Enable external content. Acetate fiber characteristics • cellulosic and thermoplastic • selective absorption and removal of low levels of certain organic chemicals • easily bonded with plasticizers, heat, and pressure • acetate is soluble in many common solvents (especially acetone and other organic solvents) and can be modified to be soluble in alternative solvents, including water • hydrophilic: acetate wets easily, with good liquid transport and excellent absorption; in textile applications, it provides comfort and absorbency, but also loses strength when wet • acetate fibers are hypoallergenic • high surface area • made from a renewable resource: wood pulp • can be composted or incinerated • can be dyed, however special dyes and pigments are required since acetate does not accept dyes ordinarily used for cotton and rayon (this also allows cross-dyeing) • resistant to mold and mildew • easily weakened by strong alkaline solutions and strong oxidizing agents. • can usually be washed or dry cleaned; generally does not shrink
  13. 13. Viscoelastic Behavior of Cellulose Acetate • Cellulose acetate (CA)/N,N-dimethylacetamide (DMA)/water • phase-separated gel formation • beta (1-4)-linked anhydroglucopyranose units(AGU) • substituted at the C-2, 3-, and 6-positions of the AGU • DS 0.5-1 soluble in aqueous solutions • (DMA) dissolves CA of DS ranging from 0.49 to 2.92 • Solvent evaporation, changes in temperature, or the addition of a nonsolvent • sol-gel transition • Hansen hydrogen-bonding solubility parameter index • Confocal scanning laser microscopy (CSLM)
  14. 14. Mixed cellulose esters (MCE) Cellulose acetate-propionate (CAP) Cellulose acetate-butyrate (CAB) thermoplastic applications Cellulose acetate-phtalates coating applications mixed acetic-aliphatic cellulose esters high hydrophobicity butyric or hexanoic anhydrides or maleic anhydride
  15. 15. Water contact angles
  16. 16. Water contact angles
  17. 17. Water vapor sorption
  18. 18. ‫ﺍﺳﺗﻔﺎﺩﻩ‬ ‫ﻣﻭﺭﺩ‬ ‫ﻣﻬﻡ‬ ‫ﻣﻧﺎﺑﻊ‬ Callum A.S. Hill, Wood Modification: Chemical, Thermal and Other Processes Collins Appaw,Richard D. Gilbert,Saad A. Khan, Viscoelastic Behavior of Cellulose Acetate in a Mixed Solvent system Jérôme Peydecastaing, Chemical modification of wood by mixed anhydrides Minna Blomstedt,MODIFICATION OF CELLULOSIC FIBERS BY CARBOXYMETHYL CELLULOSE Monica Ek,Göran Gellerstedt,Gunnar Henriksson,Pulp and Paper Chemistry & Technology Paul Gatenholm,Hemicelluloses:Science and Technology Peter Zugenmaier, Crystalline Cellulose and Derivatives, 2008 Springer