THERMAL OXIDATIVE STABILITY OF POLY-P-XYLYLENES

In the reported experiments, the air oxidation of poly-p-xylylene films was studied at temperatures between 125 and 200 degree 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 in 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 degree C for poly(dichloro-p-xylylene), 72 degree C for poly-p-xylylene.