Thermal degradation of polybis(p‐isopropylphenoxy)‐phosphazene

Polybis(p‐isopropylphenoxy)phosphazene was treated thermally at 100, 135, 200, and 300°C. The resulting reductions in weight‐average molecular weights were monitored by gel‐permeation chromatography, and the experimental observations led to the adoption of a random chain‐scission model. An effective energy of activation and entropy of activation were calculated for the degradation process, and these values were found to be consistent with a random‐scission model. The analysis was, in part, based on a computer‐simulated first‐order degradation model. This polymer showed higher thermal stability than previously reported polyaryloxyphosphazenes.