THERMAL-DEGRADATION OF BLENDS OF PVC WITH POLY(ETHYLENE ADIPATE)

The thermal degradation of PVC-PEAD blends has been studied over the whole composition range, using thermal volatilisation analysis and thermogravimetry. In the TVA studies, degradation products have been separated and characterised and in the TG experiments both temperature programmed and isothermal conditions have been used. The blend system has been found to show very similar behaviour to the PVC-poly(tetramethylene sebacate) system previously investigated, involving some stabilisation of PVC at low to moderate PEAD compositions, but destabilisation at high PEAD contents. A similar degradation mechanism in the blends is proposed, involving interaction of chlorine radicals from the PVC with PEAD, following by cross-linking.