CELLULOSE COPOLYMER

Cardanol grafted cellulose. One of the advanced techniques to improve the properties of a polymer is to graft another polymer onto it. Grafting of vinyl monomers onto cellulose has been the subject of extensive studies during the last decade or two. Grafted cellulose copolymers have been found to have improved proper-... 

Hebeish, A., and Guthrie, J. T., The Chemistry and Technology of Cellulosic Copolymers, Springer Verlag, Berlin, 1981. 

Solubility of cellulose in the products has also been used to indicate the presence of covalent bonds between cellulose and the polyvinyl copolymer. Thin sections of fibrous cellulosic copolymers, as prepared for electron photomicrography, are examined both before and after successive extractions with solvents for cellulose and for the polymer. The presence of undissolved cellulose and polymer in the extracted thin section is interpreted as evidence for the presence of covalent bonds and for grafting (52). 

Applications of ESR spectroscopy to investigations of free-radical initiated copolymerization reactions of cellulose with vinyl monomers have been reported (1, 2). NMR and infrared spectroscopy have been used to examine products obtained from degradation of cellulose copolymers to characterize the nature of the chemical bonds between cellulose and polyvinyl polymer (35, 42). Covalent bonds were indicated in most cases. 

X-ray examination of cellulose, which had been y-irradiated, showed no change in the degree of crystallinity of the cellulose (2, 5). Similarly, x-ray examinations of cellulose copolymers have not demonstrated conclusively that the formation of copolymers decreased the crystallinity of cellulose (54, 55, 57). 

Recently, scanning electron microscopy has been used in our laboratory to investigate the effects of abrasion on the morphology of fibrous cellulose copolymers (36). For example, cotton cellulose was woven into fabric form (print cloth construction and weight). Cellulose copolymer fabrics were prepared by irradiating a sample of this fabric, followed by copolymerization of the irradiated fabric with a binary mixture of acrylo-... 

The preparation of cellulose copolymers with vinyl monomers, which have functional groups that are hydrophilic in nature, has given textile products with improved soil release properties. For example, as shown in Figure 5, crosslinked cellulose-poly (methacrylic acid) copolymer fabrics exhibited both increased oily and aqueous soil release during washing compared with the crosslinked control fabrics. However, for oily soil, when softeners were added to the wash water, this improvement in soil release decreased. Crosslinked cellulose-poly (hydroxyethyl methacrylate) copolymer fabrics exhibited no improvement in oily soil release and only slight improvement in aqueous soil release compared... 

HEBEISH, A GUTHRIE, J.T. "The chemistry and technology of cellulosic copolymers" Springer Verlag N.Y. 1981... 

Tihe preparation and properties of cellulose graft copolymers have A been of considerable interest in the textile, paper, and wood products industries for a number of years. Both free radical- and ionic-initiated graft copolymerization reactions of vinyl monomers with cellulose have been reported. The vinyl-cellulose copolymers have some of the properties of both the cellulosic fibers and the grafted polyvinyl copolymers (I, 3, 47). 

Figure 10. Poly(acrylonitrile)-cellulose copolymer using y-radiation (simultaneous steps procedure)...

Figure 12. Poly(acryloni-trile)-cellulose copolymer using Ce + ion initiated copolymerization reaction...

Changing the relationship between the rate of diffusion and that of initiation is a powerful means of controlling the supramolecular structure of cellulose copolymers as well as the morphology of the modified fibre, i.e. the distribution of grafted chains in the bulk of the material. 

Hebeisch A, Guthrie JT (1981) The chemistry and technology of cellulosic copolymers. Springer, Berlin Heidelberg New York... 

Hebelsh, A. Guthrie, H.T. "The Chemistry and Technology of Cellulosic Copolymers", Springer-Verlag, Berlin Heidelberg, 1981. 

Attama, A.A. Nnamani, P.O. Adikwu, M.U. Diclofenac release from bioadhesive hydrophilic matrix tablets formulated with polyvinyl pyrrolidone-sodium carboxymethyl cellulose copolymer. J. Pharm. Appl. Sci. 2003, 1 (1), 1-7. 

A. Hebeish, J.T. Guthrie, Industrial Application of Cellulose Graft Cr lymos, The Chemisiry and Technolc y of Cellulosic Copolymers, Springer, Berlin Heidelbarg, 1981, pp. 326—342. 

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