Study of the degradation of poly(vinyl chloride) compounds by dielectric spectroscopy

A continuously recording dielectric spectrometer was constructed to investigate the effects of degradation on the dielectric spectra and ac conductivities of poly(vinyl chloride) (PVC) compounds. Dielectric spectra were found to be affected by the thermal history of the sample. The elimination‐type degradation in hard PVC and in plasticized PVC compounds could be kinetically studied by recording ac conductivity as a function of reaction time. The method was found to be useful for studying the efficiency of stabilizers in a simple way. Changes in the physical structure during the course of degradation could be measured by observing shifts and distortions of the Tg‐dispersion signals.