Stabilization of PVC by epoxidized sunflower oil in the presence of zinc and calcium stearates

摘要

Sunflower oil was epoxidized and characterized. Epoxidized sunflower oil (ESO) was used as an organic thermal co-stabilizer for plasticized polyvinyl chloride (PVC) in the presence of Zn and Ca stearates. The thermo-oxidative degradation of PVC was studied in the presence of this ternary stabilizer system at 170℃. The rates of dehydrochlorination were measured by potentiometric titration and the extents of discoloration were evaluated. The formation of polyene sequences was investigated by UV-visible spectroscopy. The influence of the ratio of Zn and Ca stearates (1/2,1/1 and 2/1) and of the amount of oxirane oxygen in the HTE were considered. Synergistic effects were found.