AN IN-SITU RAMAN-SPECTROSCOPIC STUDY OF THE DEGRADATION OF PVC

Raman spectroscopy has been used to study the in situ degradation of PVC in nitrogen and in air at different temperatures. After a rapid initial increase in the number of polyenes, the rate decreases and eventually the concentration becomes constant while the rate of dehydrochlorination is constant over the same period. These results are interpreted using a 'steady-state' approach. After a certain time the rate of formation of polyenes equals the rate of consecutive reactions of polyenes, i.e. cross-linking and oxidation. A higher degradation temperature and a higher oxygen concentration both result in lower steady-state concentration of polyene.