Effect of benzoyl peroxide on the ultrasonic degradation of poly(vinyl acetate)

The ultrasonic degradation of poly(vinyl acetate) was carried out in the pr esence of an oxidizing agent, benzoyl peroxide. The time evolution of the m olecular weight distribution (MWDs) was determined by gel permeation chroma tography. A mechanism based on radical reactions is proposed. The rate coef ficients for these reactions were determined by analyzing the MWDs by conti nuous distribution kinetics. PI stoichiometric kernel that accounts for pre ferential mid-point breakage of the polymer chains was used. The degradatio n rate coefficient of the polymer decreased with increasing benzoyl peroxid e concentration, as predicted by the model. (C) 2001 Elsevier Science Ltd. All rights reserved.