Grafting onto wool. XXX. Effects of solvent composition on the radiation-induced graft copolymerization of some acrylates onto wool fiber

Abstract

Radiation-induced graft copolymerization of ethyl methacrylate (EMA), ethyl acrylate (EA), methyl acrylate (MA), and methyl methacrylate (MMA) onto wool fiber by mutual method has been studied as a function of the composition of water-alcohol medium. Grafting of EMA, EA, and MA has been studied in nitrogen atmosphere, whereas grafting of MMA was carried out in air. Percentage of grafting (Pg) has been determined as a function of different reaction parameters that influence graft copolymerization. For all the monomers studied, it is observed that (1) maximum grafting is obtained at an optimum composition of water-alcohol medium; (2) Pg is considerably less in pure water or alcohol; (3) Pg of MA falls more sharply on addition of larger amount of MeOH to water-methanol medium as compared to EA and EMA; (4) in the case of grafting of MMA, water-isopropanol is a better reaction medium than the water-ethyl alcohol; and (5) Pg decreases considerably in air for all the monomers studied. A suitable explanation is suggested to account for these observed trends.