On the kinetics of polymer degradation. X—Laser flash photolysis of poly-α-methylstyrene in chloroform solution

Abstract

The essential step in the photolysis of poly-α-methylstyrene in chloroform solution is the interaction of singlet excited repeating units with solvent molecules (in about 10 −9s) leading to CT-complexes (decay constant 3·1 × 10 6 s −1, maxima of the optical absorption spectrum at 320 and 520–540 nm). Lateral macroradicals are formed upon the decomposition of the CT-complexes rather than via attack by solvent radicals. Oxygen does not interfere with the formation of macroradicals at concentrations up to oxygen-saturation at p O 2 = 1 bar but it reacts with macroradicals, thus preventing main-chain scission.