Volume Relaxation Rate in a-PMMA and a-PMMA/PEO Amorphous Blends

Abstract

Volume relaxation in a-PMMA and a-PMMA/PEO amorphous blends was investigated by employing a mercury-in-glass dilatometer after a temperature down-jump from equilibrium above glass transition temperature, Tg, to an aging temperature below Tg. From volume contraction isotherms, volume relaxation rate, βv = -1/V(dV/d log t), was determined as a parameter quantifying the rate of volume changes, where V is the volume and t the aging time. The addition of PEO into blends has been found to considerably increase βv.