Graft Polymerization of Some Vinyl and Allyl Polymers Onto Cellulose Using γ-Radiation-Induced Initiation

Some monomers such as vinyledene chloride, allyl chloride, and allyl alcohol failed to graft polymerize onto cellulose using ceric ammonium sulfate or sodium bisulfite-sodalime glass as initiators. Successful trials were carried out to graft polymerize these monomers using γ-irradiation from a cobalt source. The order of reactivity of the monomers used is vinyledene chloride > methyl methacrylate > ethyl acrylate > acrylonitrile > allyl chloride. This is in full agreement with the order of the reactive ability of various substituents to stabilize a radical site: Upon addition of 0.02 g lignin to the reaction mixture before irradiation, both the rate of grafting and the grafting yields decreased. The retardation and inhibition may be attributed to the quinone group found in lignin. Traces of soluble lignin in monomer also retard the graft polymerization reaction. The presence of lignin alters the order of reactivity in the initial stage. The presence of a chlorine atom on the monomer molecule highly enhanced the retarding effect of the lignin.