Synthesis, characterisation and applications of graft copolymers: Free radical graft copolymerisation of vinyl monomers onto natural polymers in aqueous media

Graft copolymerization of vinyl monomers onto natural polymers is a fascinating field of research with unlimited potential application for industrial production of various materials. The natural polymers like gellan gum, dextran, chitosan, guar gum, carboxymethylated guar gum etc. occur abundantly in nature and very useful in pharmaceuticals, food industry, agriculture, cosmetic industry, cosmetics, plastic coating material etc. Though such natural polymers have got tremendous advantages, but it suffers from drawbacks like biodegradatibility, which limits its application. Hence grafting of vinyl monomers such as N-Hydroxymethyl acrylamide, methacrylic acid, N, N-dimethylacrylamide, vinyl sulfonic acid, vinyl-sulfonic acid and 4-vinyl pyridine onto the natural polymers, not only make them highly resistant to biodegradation but also imparts other properties such as increase in water absorbency, metal ion uptake, thermal stability, antimicrobial activity and flocculation. So, in order to improves the industrial acceptance and reduce the drawbacks, research efforts are made to synthesize various graft copolymers by grafting different vinyl monomers onto natural polymers.