Thermoluminescence (TL) and oxyluminescence (OL) have been observed in polyacylonitrile (PAN) films heat-treated at elevated temperatures in vacuum and in air. In the TL curve of untreated PAN, two peaks was observed at 110 and 160°C. The peak at 110°C was attributed to the molecular motions in the paracrystalline and the peak at 110°C was the amorphous phases, respectively. The pattern of TL glow curves, in both shape and intensity, vary in a characteristic manner reflecting the heat-treatment condition.
When polymers are heated in air or oxygen atmosphere at high temperature, a light emission caused by oxydation is observed as a function of temperature. This phenomenon is called OL. The OL peak observed in the heat-treated PAN was also attributed to the molecular relaxation of PAN. It was shown that these two analysis are useful tool for investigation of the degradation and oxydation of PAN, since these are very sensitive method compared with conventional analysis such as IR spectra or DSC.