Degradation processes in polyvinylchloride

The isothermal degradation of polyvinylchloride in the temperature range 393÷423K is studied using mechanical methods. A transition from 2 overlapping first order decay processes towards a single one, as the degradation temperature is raised, has been noticed. This feature is associated with the glass transition temperature. The experimental data are consistent with an Arrhenius dependence of the preexponential factor on the degradation temperature and with a WLF like dependence of the rate constant on the degradation temperature. The estimated glass transition temperature is about 342 K. The glass transition temperature of pristine samples has been estimated to be 353 K, by electrical methods