POLARON MECHANISM IN THE THERMAL-DEGRADATION OF POLY(VINYL CHLORIDE)

On the basis of the soliton theory of electronic conductivity in polymers with conjugated polyenes, a mechanism of the thermal degradation of poly(vinyl chloride) (PVC) is proposed. The new mechanism, named the polaron mechanism, shows that in the thermal degradation of PVC, the main features of the propagation reaction should be explained in terms of polarons rather than in terms of allylic chlorines or radicals as previously suggested. This polaron mechanism describes the chain degradation well, and establishes the unique process by which electron acceptors like Lewis acids or oxygen accelerate the degradation.