Tracer study of azodibenzoyl as an initiator of radical polymerization

Abstract

Azodibenzoyl sensitizes the polymerization of methyl methacrylate at 90°C but degradative transfer to initiator is pronounced. Tracer techniques have been used to determine the rate of initiation of polymerization and the rate of the primary dissociation of the azo compound to radicals. Comparison of these rates shows that the efficiency of initiation is about 75 %. There is some indication of geminate recombination of benzoyl radicals.