Cellulose thiocarbonate-ferric nitrate redox system induced graft copolymerization of vinyl monomers on to cotton fabric

Abstract

The cellulose thiocarbonate-ferric nitrate redox system was investigated as the initiator for the graft copolymerization of methyl methacrylate (MMA) and other vinyl monomers on to cotton fabric. Other monomers were methacrylic acid (MAA), acrylonitrile (AN), methyl acrylate (MA), acrylamide (Aam), ethyl acrylate (EA), and allyl acrylate (Allyl-A). A number of variables in the grafting reaction were investigated, including ferric nitrate and monomer concentrations, pH of the polymerization medium, duration and temperature of polymerization, and composition of the water/solvent polymerization medium, solvents used being methanol, ethanol, isopropanol, tertiary butanol, and acetone. The grafting reaction was studied with respect to various polymer criteria, namely, graft yield, homopolymer formation, total conversion, and grafting efficiency. The optimal conditions for low homopolymer formation and high grafting efficiency were [Fe(NO 3) 3.9H 2O], 6 m mol/litre; MMA, 2%; pH, 2; polymerization time, 2h; polymerization temperature, 60°C; material/liquor ratio 1:50. The rates of grafting under these optimal conditions were in the order: methyl methacrylate > methyl acrylate > ethyl acrylate > allyl acrylate > acrylamide > acrylonitrile > methacrylic acid. A tentative mechanism for the grafting reaction is proposed.