Ultraviolet irradiation of poly(ethyl acrylate) in vacuum. II. Mechanism of the reaction

摘要

AbstractIrradiation of poly(ethyl acrylate) films in the absence oxygen with ultraviolet light of 254 mp wavelength results in chain scission and crossliking. The effects of film thickness, light intensity, and temperature of irradiation on this process have been determined, and the volatile reaction products have been analyzed in the mass spectrograph. The data suggest that the primary result of irradiation is splitting off ester side chains. The polymer radicals remaining can crosslinked by combination with one another or cleaved a decomposition reaction. There is a large change observed in the rate of the crosslinking reaction in the neighborhood of the glass transition temperature (−17°C.), but scission reaction shows only a very small temperat