Thermal oxidative stability of poly-p-xylylenes

The air oxidation of poly‐p‐xylylene films was studied at temperatures between 125 and 200°C. The oxidation kinetics were obtained from neutron activation (NA) oxygen analyses and infrared (IR) Spectroscopy. A correlation between the NA oxygen analyses and mechanical properties indicated that the amount of oxygen incorporated into these polymers before a significant degradation mechanical properties is about 1000 ppm for poly(dichloro‐p‐xylylene) and 5000 ppm for poly(monochloro‐p‐xylylene) or poly‐p‐xylylene. The activation energy for the oxidation of these polymers was about 30 kcal/mole. Long‐term‐use (100,000 hr) temperatures were also estimated for each of the poly‐p‐xylylenes studied. The 100,000‐hr maximum continuous‐use temperature is 112°C for poly(dichloro‐p‐xylylene), 72°C for poly(monochloro‐p‐xylylene), and 57°C for poly‐p‐xylylene.