DECOMPOSITION OF POLY(VINYL CHLORIDE) IN BLENDS WITH NITRILE RUBBERS

Thermal decomposition of PVC blends with nitrile rubbers SKN-18, SKN-26, and SKN-40 was studied. Due to the presence of nitrogen-containing groups, rubbers increase the rate of PVC decomposition. The rate of PVC dehydrochlorination also increases due to both the effect of nitrogen-containing groups and the effects of the products of their interaction with HCl-(hydrochloride complexes). The kinetics of thermal decomposition of PVC-NR films was studied. The effective rate constants of PVC catalytic dehydrochlorination conditioned by nitrile groups and hydrochloride complexes, the decomposition rate constant of hydrochloride complexes, and the complexation rate constant of HCl and nitrile groups were calculated. PVC decomposition in blends with NR in 1,2,3-trichloropropane and cyclohexanone solutions were examined. Considerable differences were found between the processes of PVC decomposition in blends with NR proceeding in the presence of a solvent as compared to without one.