Conformational recovery of poly(vinyl chloride) glasses prepared under pressure

Abstract

The recovery of polyvinyl chloride glasses prepared at high temperature and pressure (120 °C, 7 kbar) have been observed using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Changes in absorbance associated with conformational reequilibration occur above 80 °C, the normal glass temperature of polyvinyl chloride (PVC). Peaks are observed in Cp 15–20 °C below Tg which are attributed to relaxation of volume strain or holes. Since the enthalpy and the conformational recovery occur at different temperatures and time scales, we conclude that neither free volume models nor flexed bond models are adequate to explain the properties of glasses prepared at high pressure.