FACTORS AFFECTING STABILITY OF POLY(VINYL CHLORIDE) IN A POLY(VINYL CHLORIDE)-POLY(METHYL METHACRYLATE) BLEND IN SOLUTION

Thermal stability of poly(vinyl chloride) (PVC) in PVC-poly(methyl met hacrylate) blends in cyclohexanone and 1,2,3-trichlorpropane was studi ed. It was shown that the rate of degradation of PVC is determined by two factors: On the one hand, the rate of degradation depends on the e ffect of the solvent on the decomposition of PVC, in particular, throu gh its solvating action; on the other hand, the rate of degradation is affected by the other polymer. The effect of the second polymer is ex plained by the fact that methyl ether, which is formed as the result o f decomposition of poly(methyl methacrylate) (PMMA), can influence the thermal stability of polyvinylchloride. At the same time, PMMA can ch ange the states of dissolved PVC macromolecules, thus causing changes in the rate of PVC dehydrochlorination.