MISCIBLE BLENDS OF ATACTIC POLYSTYRENE AND POLY(2,6- DIMETHYL-1,4-PHENYLENE OXIDE): PART 1. NON-EQUILIBRIUM GLASSY BEHAVIOR PROBED BY CALORIMETRY AND DILATOMETRY

摘要

Temporal changes in properties below T_g are associated with the inherently non-equilibrium nature of the glassy state, and these thermoreversible changes are collectively termed physical aging. Physical aging rates were investigated as a function of composition for amorphous miscible blends of atactic polystyrene (a-PS) and poly(2,6-dimethyl-l,4-phenylene oxide) (PPO) using DSC and dilatometry to assess relaxation rates for enthalpy and volume, respectively. The influence of the changing thermodynamic state on mechanical creep compliance characteristics was also investigated for this blend system.