无规聚甲基丙烯酸甲酯在聚乙二醇齐聚物溶液中的自组织及凝胶行为

高度立构规整的聚甲基丙烯酸甲酯在许多有机溶剂中都有形成热可逆凝胶的倾向[1] .高间规度的聚甲基丙烯酸甲酯 ( s PMMA)在溶液及凝胶中的自组织行为可以通过核磁共振、光散射、小角中子散射及红外光谱来研究 [2～ 5] .在甲苯、邻二甲苯和邻二氯苯等溶剂中 ,s PMMA链中的大部分单元都处于有序状态 ;而在苯和氯仿等溶剂中 ,没有这种有序结构形成 ,分子链处于无规线团状态 [5,6] .一般认为 ,这种有序结构的形成与分子链中一定长度间规序列结构单元的存在有关 [7] .对于无规聚甲基丙烯酸甲酯 ( a PMMA) ,由于其较低的间规度 ( <66% ) ,在…

Self-aggregation and Gelation Behavior of Atactic Poly(methyl methacrylate) in Poly(ethylene glycol) Oligomers

The self|aggregation and gelation behaviors of atactic poly(methyl methacrylates)(aPMMA) in poly(ethylene glycol)(PEG) oligomers were studied by using FTIR spectroscopic measurements. The in|situ variable temperature IR studies in aPMMA/PEG gel suggested that some aPMMA segments were in the aggregated state in solution, which became a node in the solution. With decreasing temperature, the fraction of aggregated aPMMA in solution increases, resulting in the gelation of aPMMA.