Investigation of autocatalytic thermal degradation of poly(vinyl chloride) by ESR spectroscopy

Abstract

The dehydrochlorination of PVC under vacuum with continuous removal of HCl and in the presence of HCl, has been studied at 200 °C. The dependences of the intensity of the ESR signal of degraded PVC on time of degradation and HCl loss conversion have been obtained. In PVC degradation in the presence of HCl, they have an autocatalytic character. At the same percentage of dehydrochlorination, the spin concentration is significantly more in the PVC degradation in the presence of HCl than with removal of HCl. The conclusion has been made that the formation of paramagnetic centers in degraded PVC is intensified by the presence of HCl. It has been shown that during autocatalytic PVC degradation, H 2 practically does not form. The obtained results are discussed in terms of a theory of the autocatalytic thermal degradation of PVC as a branched chain reaction with degenerate branching of the chain.