REACTION OF POLY(VINYL ALCOHOL) WITH POTASSIUM PERSULFATE AND GRAFT COPOLYMERIZATION.

A study of the oxidation of PVA by potassium persulfate (KPS) in aqueous solutions is reported which shows that the decomposition of KPS was greatly enhanced by the presence of PVA, its hydroxyl groups being oxidized to ketones in a yield of about one mole of ketone from one mole of KPS. The decomposition rate of KPS was found to be given by the equation, - d left bracket S//2O//8**2** minus right bracket /dt equals k left bracket S//2O//8**2** minus right bracket left bracket PVAL** one-half , which was essentially the same as in the oxidation of alcohols of low mol. wt by persulfate ion. The occurrence of gelation of PVA solutions and graft copolymerization of methyl methacrylate (MMA) onto PVA in the presence of KPS was evidence for PVA radical as an intermediate species in the oxidation of PVA. A characterization study was also carried out for the reaction products of the graft copolymerization of MMA onto PVA with KPS in dimethyl sulfoxide solution.