DECOMPOSITION OF POLYVINYL-CHLORIDE IN BL ENDS WITH NITRILE RUBBERS

Thermal decomposition of PVC blends with nitrile rubbers SKN-18, SKN-2 6, and SKN-40 was studied. Due to the presence of nitrogen-containing groups, rubbers increase the rate of PVC decomposition. The rate of PV C dehydrochlorination also increases due to both the effect of nitroge n-containing groups and the effects of the products of their interacti on with HCl (hydrochloride complexes). The kinetics of thermal decompo sition of PVC-NR films was studied. The effective rate constants of PV C catalytic dehydrochlorination conditioned by nitrile groups and hydr ochloride complexes, the decomposition rate constant of hydrochloride complexes, and the complexation rate constant of HCl and nitrile group s were calculated. PVC decomposition in blends with NR in 1,2,3-trichl oropropane and cyclohexanone solutions were examined. Considerable dif ferences were found between the processes of PVC decomposition in blen ds with NR proceeding in the presence of a solvent as compared to with out one.