This project will investigate lateral variation in the polymer autoxidation reaction mechanism. The first step is a chemiluminescence (very low intensity light emission) imaging survey of several polymers in the steady state, autocatalytic and oxygen limited stages of autoxidation. Other laterally resolved analytical techniques will be used to relate polymer attributes to the mechanistic heterogeneity. Brief ultraviolet irradiation will be used to stimulate polymer chemiluminescence. Lateral variations in relaxation of the stimulated chemiluminescence to steady state intensity will be examined. The capability for laterally resolved measurement of the glass-to-gel transition temperature will be developed. The analytical methods used will be related to polymer aging and used to develop polymer failure prediction models. A potential new instrument resulting from the research would provide non-destructive field testing to predict useful service life of polymeric materials.