Volume relaxation in amorphous polymers around glass-transition temperature.

Abstract

Relaxation of volume, enthalpy, and dielectric polarization have been studied for poly(vinyl acetate) and polystyrene around a glass-transition point. It has been concluded that the correlation time of microbrownian motion in glassy polymers shifts with time during the period of volume relaxation. The time dependence of dielectric relaxation time ηD has been represented approximately bylogτD=alogt−b where a and b denote constants. By application of this equation to the volume and enthalpy relaxation processes, the time dependence of the specific volume V(t) or enthalpy H(t) can be represented in the form V(t)−V(∞)=ct−B where B and c are constants. The values of B for the volume relaxation agree well with those for the enthalpy. © 1978, The Society of Polymer Science, Japan. All rights reserved.