PBMA-b-PSt磺化嵌段离聚体在DMF溶液中的聚集行为

采用激基缔合物荧光光谱法研究了轻度磺化聚甲基丙烯酸丁酯－b－聚苯乙烯（PBMA-b－PSt）嵌段离聚体在极性溶剂N，N－二甲基甲酰胺（DMF）溶液中的聚集行为；发现嵌段离聚体的磺化度和浓度强烈影响溶液中聚合物链的聚集态结构，不同的磺化度样品具有不同的临界聚集浓度；随磺化度增加，聚合物链缠绕密集，形成具有多苯环的聚集体，而且当磺化度为摩尔分数x＝3．59％时，荧光发射光谱最大发射峰波长出现最大红移，临界聚集浓度最低，说明最容易形成多苯环聚集体，该磺化点可以认为是磺化聚甲基丙烯酸丁酯－b－聚苯乙烯体现离聚体行为和聚电解质行为的临界磺化度。

Aggregation Behavior of Sulfonated PBMA- b- PSt Block Ionomers in DMF Solutions

Aggregation behavior of sulfonated poly(butylmethacrylate-b-styrene(PBMA-b-PSt)block iono_mer in polar solvent DMF was investigated by excimer fluorescence spectrum. It is found that the sulfonation degree and concentration of the block ionomers strongly effect on chains state of aggregate. The block ionomers with different sulfonation degrees have different critical aggregation concentration. The maximum emission wavelength of the excimer increases with the concentration of the block ionomers. The red shift of the maximum emission wavelength is the largest at sulfonation degree of 3.59%(mole fraction). In this case polymer chains of sulfonated PBMA-b-PSt block ionomers have the most aggregative compactibility. The sulfonation degree of 3.59% may be regarded as a critical sulfonation degree at which the polymers would display behavior as an ionomer or a polyelectrolyte.