Kinetic and chemical studies of polymer cross-linking using thermal gravimetry and hyphenated methods. Degradation of polyvinylchloride

The chemistry and kinetics of polyvinylchloride (PVC) degradation have been studied using thermal gravimetry and hyphenated spectroscopic methods to identify condensed phase and vapour phase products. A method of kinetic modelling has been devised to estimate Arrhenius parameters for the sequential and competing processes which comprise the thermal decomposition, and to plot concentrations of decomposition intermediates which make up the TG curve. MS and GC-MS have been used to relate the composition of volatile materials to the TG curve and FTIR has related this to changes in the condensed phase. The chemical studies have highlighted a char forming mechanism based on hydrogen disproportionation which results in carbon enrichment and the formation of aliphatic hydrocarbons. (C) 1999 Elsevier Science Ltd. All rights reserved.