Thermal degradation of PVC in the presence of polystyrene

The thermal degradation of poly(vinyl chloride) (WC) and blends of PVC with polystyrene has been studied using thermogravimetric analysis coupled to Fourier transform infrared spectroscopy. The degradation of WC commences at weak links by an ionic pathway, but there is evidence to suggest the presence of a radical pathway at high temperatures. While there is some chemical interaction between WC and polystyrene, the principal mode of stabilization is a physical process.