Thermal stability characterization of plasticized PVC compounds using calcium and zinc stearates

Thermal stability of plasticized PVC compounds (50 phr di(2-ethyl hexyl) phthalate and 0 or 5 phr of epoxidized soybean oil) was studied. The effect of Ca/Zn stearate ratio (0.0/1.0, 0.2/0.8, 0.4/0.6, 0.6/0.4, 0.2/0.8 and 1.0/0.0) and total amount of stearates (0.25, 0.5, 1.0 and 2.0 phr) was considered. The effect of presence of epoxidized soybean oil was evaluated only in formulations containing 2.0 phr of stearates. Degradation behavior was followed by color evolution (yellow index and Lab color coordinates), measurement of gel content, total amount of HCl and polyene produced and mass loss rate