Decomposition of poly(propylene carbonate) with UV sensitive iodonium salts

The decomposition characteristics of poly(propylene carbonate) containing a photoacid generator have been studied. The influence of casting solvent, photoacid concentration and type, UV exposure dose, substrate surface, and ambient gas were included in this study. Dynamic thermogravimetric analysis was used to analyze the decomposition characteristics. Kinetic parameters were extracted using the Kissinger method and the Coats-Redfern method. Fourier Transform Infrared Spectroscopy was used to analyze effects of casting solvent. The highest thermal stability was found to occur in high molecular weight, high-purity poly(propylene carbonate) samples. Cyclohexanone and trichloroethylene solvents were found to increase the thermal stability. Photoacid generators based on diphenyliodonium salts lowered the onset decomposition temperature and activation energy.