Quantitative relationships between the parameters of thermal degradation of polyvinyl chloride and the loss of mechanical properties

摘要

Thermal degradation of polyvinyl chloride (PVC) was studied to obtain quantitative relationships between temperature and duration of polymer degradation and the corresponding loss of tensile strength, flexural modulus, and impact strength. Test specimens of rigid PVC containing different concentrations of dibutyltin bis(isooctylthioglycolate) and barium-cadmium stearate were subjected to five different temperatures for five different durations. The selected test properties were determined before and after degradation. Percentage property retention was plotted against logarithm of heating time. Values of log heating time corresponding to acceptable levels of property retention obtained from these plots were then plotted against temperature to obtain Arrhenius-type relationships between the parameters of thermal degradation and the deterioration of properties.