THE EFFECT OF HOT DRAWN ON THE PHYSICAL AGING OF ATACTIC POLYSTYRENE

• 来源期刊: 高分子科学（英文版）
• 学科: 化学
• 年，卷（期）: 1998,（2）
• 页码范围: 176-184
• 页数: 9页
• 分类号: O6
• 语种: 英文

摘要

The physical aging behavior of atactic polystyrene (aPS) films achieved under different drawing conditions has been studied by optical birefringence and modulate differential scanning calorimeter (m.d.s.c.). The results show that on annealing at specific temperature below glass transition temperatue (Tg), the enthalpy relaxation (△H) and Tg decrease with increasing of birefringence (△n). On the other hand, the effect of molecular draw ratio (MDR) is confusing: △H and Tg decrease with increasing of MDR in the early stage of aging, but the MDR's effect become unobvious with the development of aging.It may be concluded that the ordered domain generated by the drawing below or above glass transition temperature will affect the development of physical aging behavior. The viewpoint of cohesional entanglement is used to account for the above observations.