The study of degradable polystyrene: Photolysis in solution and photo-oxidation in films

Radical copolymerization of styrene with benzalacetophenone or benzalacetone in bulk or in suspension yielded copolymers with as much as 10 wt% of carbonyl monomer. They were characterized by GPC, viscometry and spectroscopy. Photolysis of copolymers was investigated in benzene at 313 nm. Quantum yields for main chain scissions were about 0.005 and the life-time of the triplet state was 5 nsec. Photo-oxidation in films was followed by monitoring the decrease in molecular weight and by i.r. and emission spectra. Quantum yield for main chain scission in films was about 0.0002. During photooxidation in film, the molecular weight distribution widened. A new i.r.-band appeared at 3580 cm^?1 and the carbonyl band was spread between 1700 and 1800 cm^?1. In the emission spectra, the vibrational resolved emission (typical of the carbonyl chromophore) disappeared.