Influence of βRelaxation on Isothermal Structural Recovery using KAHR Model

摘要

The classic Kovacs-Aklonis-Hutchinson-Ramos (KAHR) model of structural recovery is used to simulate polystyrene aging deep in the glassy state for long aging times by adding the ? relaxation mechanism to the model. Two sets of parameters for the modified model are considered. The goal is to investigate whether the ? relaxation processes is the origin of recent controversial observations, including multiple steps or plateaus in isothermal structural recovery and a broad shallow DSC peak observed in the glassy state on heating after low temperature aging. The results indicate that the ? relaxation is not the cause of these anomalous observations.