Optimum temperature for oxidative degradation of poly(vinyl acetate) in solution

The oxidative degradation of poly(vinyl acetate) (PVAc) was carried out in presence of benzoyl peroxide at 70-123 degreesC in a batch reactor by dissolving PVAc in chlorobenzene. The molecular weight distributions(MWDs) were measured as a function of reaction time by gel permeation chromatography. Experimental data indicates degradation occurs by random chain scission only without cross-linking and repolymerization. A radical mechanism for the oxidative degradation was proposed and modeled based on continuous distribution kinetics. An optimum temperature of 110 degreesC was observed for maximum degradation. The energy of activation of the random scission oxidative degradation rate coefficient, determined from the temperature dependence, was 20 kcal/mol