Copolymers, graft cellulosic type

In general, graft copolymers consist of a polymer backbone to which another polymer is chemically attached as side chains. The backbone and side chain polymers may be homopolymer, random copolymers, block copolymers or mixtures of the various types. For example, most graft copolymers of cellulose consist of a homopolymer backbone (cellulose) and another homopolymer (e.g. polystyrene) or a random copolymer (e.g. polystyrene-co-acrylic acid). 

Graft copolymerization Graft copolymers are a type of branched copolymers with distinct side structures from the main chain. Graft copolymerization initiates the free radicals on cellulose molecule that can react with the hydrogen bonds on the matrix. Acrylic acid, acrylonitrile, and vinyl monomers are used for graft copolymerization of natural fibers. Equation 9.3 depicts the reaction of acrylonitrile with the fiber... 

The morphology of the fibrous cellulose graft copolymers depended on the method of initiation of free radical formation, experimental conditions during the copolymerization, chemical modification of the cellulose before reaction, and the type of monomer used (60). Variations in the shape of the fibrous cross section, in layering effects in the fiber, and in the location and distribution of the grafted copolymer in the fiber were observed by electron microscopy (61). Cotton cellulose—poly (acrylonitrile) copolymer was selected to show the possible variations in location and distribution of the grafted copolymer in the fiber. 

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