Oxidative Thermal Degradation of Selected Polymeric Spacecraft Materials

Abstract

A number of commercial polymeric materials used in U. S. spacecraft and airplanes were investigated from the point of view of oxidative thermal stability and toxicity of possible volatile oxidation products. To this end, methods of thermal analysis (dta, tga, dtg) were applied to study the oxidation profiles of five different groups of polymers in pure oxygen at 14.7 psi, at 5 psi, and in a mixture of 50% N₂ and 50% O₂ at 5 psi. The volatile reaction products were collected and then separated and identified by combined gas chromatography-mass spectrometry.

In a few preliminary experiments, thermal degradation was performed in steps corresponding to steps in the thermogram. The volatiles pertaining to each step were collected and analyzed. Results from the thermal and GC/MS analyses were correlated to possible oxidative degradation mechanisms.