Thermal degradation of polyethylene and polytetrafluoroethylene during vacuum evaporation

Abstract The thermal breakdown of polyethylene and PTFE has been studied by means of an MS 10 Mass Spectrometer. Spectrometer traces are presented which show that polyethylene degrades to homologous series of hydrocarbons including the paraffins, olefins and higher order acetylenes. The polyethylenes. The polyethylene was maintained at 400°C during degradation at a total indicated pressure of 10 −5 torr. The PTFE samples were evaporated at 500° C at a total indicated pressure of 1.5×10 −5 torr and degraded to give mainly CF, CF 2 , C 2 F 3 , OCF 2 and OC 2 F 5 compounds. No homologous series of fluorocarbons were observed.