Photodegradation of High Polymers Iniin Solution. Part 1. Solvent Effects in the Photolysis of Poly (Alpha-Methylstyrene)

摘要

The photodegradation of poly (alpha-methylstyrene) was investigated in the presence and absence of air in a series of solvents under irradiation by a low pressure mercury lamp at about 25C. Changes in the intrinsic viscosities of the solutions as well as spectral changes are used to follow the course of the degradation. Under most conditions, random scission is the major degradation reaction; no crosslinking is observed. Empirical comparisons of the ultraviolet spectral changes resulting from the irradiation of poly (alpha-methylstyrene), poly(styrene), and analogous hydrocarbons indicate that a free radical reaction occurs initially at the methylene group in the polymer backbone. Mechanisms are suggested. (Author)