Degradation mechanism of γ-irradiated polytetrafluoroethylene (PTFE) powder by low-temperature matrix-isolation infrared spectroscopy and chemiluminescence spectroscopy

In order to elucidate the mechanism of degradation of γ-irradiated polytetrafluoroethylene (PTFE), gases evolved by isothermal heating under vacuum were trapped in low-temperature argon matrices. Infrared spectra of the evolved gases were assigned to COF2 and CF4 by comparison with the corresponding literatures. Kinetic analyses of the IR absorbance and chemiluminescence intensity changes against heating time were carried out to determine the rate constants of the thermal reactions, showing that CF4 was produced more rapidly than COF2. By comparison between the rate constants obtained by infrared spectroscopy and chemiluminescence spectroscopy, we propose a new thermal reaction mechanism of γ-irradiated PTFE at the molecular level.