Thermal degradation of bisphenol A polycarbonate by high‐resolution thermogravimetry

Abstract

Thermal degradation of bisphenol A polycarbonate (PC) has been studied in nitrogen and air from room temperature to 900 °C by high-resolution thermogravimetry (TG) with a variable heating rate in response to changes in the sample's degradation rate. A three-step (in nitrogen) or four-step (in air) degradation process of the PC, which was hardly ever revealed by traditional TG, has been found. The initial thermal degradation temperature of the PC is higher in nitrogen than in air, but the three kinetic parameters (activation energy E, decomposition order n, frequency factor Z) of the major degradation process are slightly lower in nitrogen. The average E, n and lnZ values determined by three methods in nitrogen are 154 KJ mol−1, 0.8 and 21 min−1, respectively, which are almost the same as those calculated by traditional TG measurements. © 1999 Society of Chemical Industry