High-resolution thermogravimetry of poly(phenylene sulfide) film under four atmospheres

The thermal degradation of poly(phenylene sulfide) (PPS) film is investigated in air, nitrogen, helium, and argon with different physical and reactive characteristics at room temperature to 790degreesC as ascertained by high-resolution thermogravimetry (TG) at a variable heating rate in response to the changes in the sample's weight-loss rate. Only a one-step degradation process of the PPS is observed in nitrogen and argon, but a two-step degradation process of PPS is found in helium. A four-step degradation process of the PPS, which is hardly ever revealed by traditional TG, is found in this investigation, especially in air. The initial thermal degradation temperature and temperature at the first maximum weight-loss rate of the PPS increase in the following order: helium < nitrogen < argon < air. The first maximum weight-loss rate also increases with the variation of the atmosphere in the order nitrogen < air < argon < helium. The char yield at 700degreesC increases in the order air < helium < nitrogen < argon. The activation energy of the major degradation process of PPS, as calculated based on the high-resolution TG data, is very high and increases in the order nitrogen < argon < helium < air. The thermal decomposition parameters of the PPS determined by the high-resolution TG are systematically compared with those by traditional TG at a constant heating rate. (C) 2002 John Wiley Sons, Inc.