物理老化无规聚苯乙烯屈服机理的研究  

A Study of Stress-Yielding Mechanism of Aged Atactic Polystyrene

作　　者：宋锐[1] 赵军[1] 杨娟[1] 令狐欣[1] 高金贵[1] 范庆荣[1] 

机构地区：[1]高分子物理与化学国家重点实验室

出　　处：《高等学校化学学报》2001年第2期303-306,共4页Chemical Journal of Chinese Universities

基　　金：国家基础研究重大项目!"高分子凝聚态基本物理问题研究"资助

摘　　要：利用机械拉伸、示差扫描量热 (DSC)以及溶剂溶胀等方法研究了物理老化后的无规聚苯乙烯 (α PS)的应力屈服行为 ,并从凝聚缠结的观点对实验结果进行了解释 .实验结果表明 ,经物理老化后的α PS在拉伸过程中出现应力屈服峰实质上是逐步打开凝聚缠结的过程 .凝聚缠结是聚合物非晶相在物理老化过程中相邻的两三条链的局部链段由于范德华吸引力的作用形成的一种有序结构 ,其作用能很弱 ,升温至Tg 附近 ,机械拉伸至屈服点以及溶胀剂都可将其完全破坏 .The stess yielding mechanism of aged atactic polystyrene(α-PS) was studied by use of mechanical tension, differential scanning calorimetry(DSC) and solvent-swelling. The viewpoint of cohensional entaglement(CE) was empolyed to interpret the experimental results, which indicated that the stress yielding of aged α-PS was the destruction of the CE formed during aging. CE was a kind of ordered structure, which was formed by local parallel alignment of several segments of several nearest neighboring chains. Its interaction energy was so low that heating beyond theT_g region, mechanical drawing over the yield point and solvent swelling all could destroy it completely.

关 键 词：无规聚苯乙烯 应力屈服 凝聚缠结 物理老化 机械拉伸 DSC 溶剂溶胀 

分 类 号：O632.13[理学—高分子化学] O631.21[理学—化学]