Relaxations of damped Debye lattice; partially brominated poly(2,6-dimethyl-1,4-phenylene oxide)

Abstract

The damped Debye lattice (DDL) has been applied to the viscoelastic behavior of the partially brominated poly(2,6-dimethyl-1,4-phenylene oxide) (PBrPO). PBrPO ordinarily conforms to a two-dimensional DDL model with the steepness index (SI) of 1.0. When PBrPO was plasticized with dioctyl phtalate and dioctyl sebacate, as predicted by the model, an unusual sharpening of the transition region in stress relaxation master curve is shown by an increase in the SI from 1.5 to 0.5, on further plasticization. This behavior is associated with changes in the size of interchain force constants produced by various concentration of plasticizer