Thermal‐oxidative degradation of poly(ethyl acrylate)

Abstract

AbstractThe thermal‐oxidative degradation of films of poly(ethyl acrylate) about 35 μ thick were studied in the temperature range of 80 to 120°C. The degradation was followed by determining intrinsic viscosity changes, absorption of oxygen, and production of titratable acidity in the polymer. From viscosity results an apparent activation energy of 28.6 kcal. was calculated. Only very slight degradation occurred when the polymer was heated in a vacuum. In air, the reaction is inhibited by the presence of hydroquinone, while the addition of benzoyl peroxide caused a rapid degradation even in a vacuum. The rate of oxygen absorption was found to be similar to that typical of autocatalytic oxidations. Oxygen diffusion did not appear to be the rate‐determining factor in the degradation of films 10 to 70 μ thick. The weight loss during degradation was very small, but infrared and mass spectra indicated the presence of carbon dioxide, ethanol, formic acid, and water among the volatile products. A degradation mechanism based on hydroperoxide formation and decomposition is suggested.