Copolymerization of Styrene with Benzylideneacetophenone or Benzylideneacetone and Photodegradability of Copolymers

Abstract

Photodegradable polymers containing carbonyl groups were prepared by copolymerization of styrene with benzylideneacetophenone or benzylideneacetone and the monomer reactivity ratio was determined for these copolymerization systems. The results are as follows: St (M₁) - BAPh (M₂) r₁=0.84 ± 0.05, r₂=0.02 ± 0.10; St (M₁)-BA(₂) r₁=1.76 ± 0.02, r₂= -0.1 ± 0.1. The structure of copolymers was analyzed by IR spectra. By applying the method of emulsion polymerization without initiators, new method of obtaining high-molecular weight copolymers was developed. The photodegradable behavior of the styrene-benzylideneacetophenone copolymers was traced in terms of molecular weight determination by GPC, UV and IR spectra after irradiation to their benzene solution with high-pressure mercury lamp. It was found that the decarboxylation occurs at side chains and at the same time the scission of main chains proceeds markedly in terms of the. Norrish II mechanism.