Thermo-oxidative degradation of poly(vinyl chloride) in the presence of derivatives of Khaya seed oil

Thermal degradation studies of poly(vinyl chloride) in the presence of epoxidised Khaya seed oil and metal soaps (barium, cadmium, lead and zinc) of the oil under oxidative conditions were carried out at 190 °C. Changes in average molecular weight of the number polymer, chain scission per polymer molecule, obtained from intrinsic viscosity measurements in cyclohexanone solution and levels of unsaturation in degraded polymer samples were used to evaluate the effect of epoxidised Khaya seed oil and its metal soaps on the susceptibility of poly(vinyl chloride) to thermal degradation. It was found that the metal soaps of epoxidised Khaya seed oil reduced the level of unsaturation in the degraded polymer sample and the extent of the polymer chain scission, which accompanied dehydrochlorination. The stabilising effect of barium and cadmium soaps of the seed oil was also indicated from thermogravimetric and IR spectrophotometric studies.