KINETICS OF THE THERMAL-DEGRADATION OF POLY(PHENYLENE SULFIDE)

The thermal degradation behaviour of two commercial samples of poly(phenylene sulfide) (PPS), Ryton P-4 and Fortron 0205B4, has been examined by both dynamic and isothermal thermogravimetric analysis. The kinetic parameters, i.e. the pre-exponential term, log A, and the apparent activation energy E have been determined by applying the Kissinger and Ozawa-Flynn methods to the dynamic heating rate data, together with the values derived from the isothermal experiments using initial reaction rate data and using the whole data analysed by reduced-time-plots. The E values determined for the Ryton sample using these analyses were found to be 162, 183, 166 and 179 kJ mol-1 respectively. The Fortron sample gave the values 178, 169, 145 and 147 kJ mol-1. Application of lifetime estimates to the kinetic data yields 10-year maximum temperature values of between 198 and 235-degrees-C and between 180 and 222-degrees-C for the Ryton and Fortron samples respectively. Lower values were obtained from the isothermal data which may reflect a thermal lag effect upon introduction of the samples.