THERMAL STABILIZATION OF PVC VIA THE POLARON MECHANISM .3. STABILIZATION WITH ORGANOTIN COMPOUNDS

By the polaron theory, it has been shown that the stabilisation of pol y(vinyl chloride) (PVC) with organotin compounds is due to many differ ent reactions: (1) substitution of the-activated hydrogen in PVC by th e stabiliser molecule or by-products of the stabiliser, this reaction being one of the most important because it takes place throughout the stabilisation; (2) substitution by the stabiliser of labile chlorine a toms, which occurs only in the early stages of the induction period; ( 3) saturation of the degraded PVC by by-products of tin compounds or H Cl; and (4) stabilisation due to the interaction of organo groups with the degraded PVC. (C) 1996 Published by Elsevier Science Limited.