Fourier Transform IR Studies of the Uninhibited Autoxidation of Elastomers

The oxidative degradation of elastomers is an autocatalytic process and is termed autoxidation, A plot of time versus the oxygen consumed during the degradation results in an S-shaped curve which is characteristic of autocatalysis. The autoxidation of hydrocarbons is a chain reaction of free radicals and can be represented in general form by the following set of equations ( 1, 2 ): The autocatalytic process can be initiated by thermal, photo, chemical, or mechanical means. It usually begins by the decomposition of small amounts of hydroperoxides which were formed during the preparation and fabrication of the polymer. The decomposition may occur either uni- or bimolecularly to form alkoxy and peroxy radicals. These oxy radicals abstract a labile hydrogen from the hydrocarbon to produce either an alcohol or a hydroperoxide. The alkyl radical thus formed readily adds oxygen to reform a peroxy radical, and the process continues. When the autoxidation occurs in the