Polytetrafluoroethylene decomposition in air and nitrogen

The kinetics of the thermal decomposition of polytetrafluoroethylene (PTFE) have been studied using dynamic TG-DTG at heating rates between 1 and 25 degreesC/min at atmospheric pressure. Two different atmospheres were used: on the one hand, an inert atmosphere (N-2) in order to study the pyrolysis of the material, and on the other hand an oxidative atmosphere (synthetic air) to study the combustion of the polymer. The same kinetic model has been applied simultaneously to runs performed at different heating rates and different atmospheres allowing a good correlation of the weight loss data. The kinetic model considers that the overall decomposition of the PTFE is done via two different parallel processes. Dynamic measurements were performed by combined thermogravimetry mass spectrometry (TG-MS) in order to determine the decomposition products. The evolution of C2F4, CF4, COF2, HF, hydrocarbons, benzene and some other compounds has been also analyzed.