A new approach to synthesizing amphiphilic miktoarm star polymers (MPEG)₂(PCL)₂ based on sydnone-maleimide double cycloaddition (SMDC) was investigated using “coupling-onto”, “in–out” and “one-pot” methods. The double 1,3-dipolar cycloadduct could be conveniently obtained by a SMDC reaction between the “arms” maleimide-terminated prepolymers and the “core” N-phenylsyndone. No matter what the molar ratio of sydnone and maleimide groups was, the double cycloaddition products would not be changed. The star polymers synthesized by the “coupling-onto” approach had the narrowest polydispersity, and the “one-pot” approach was the most convenient. The SMDC reaction greatly simplified the synthesis procedure, moreover it had a good control of the structure of miktoarm star polymers. All the polymers’ structures were characterized by ¹H NMR, FT-IR and GPC. Their thermal properties were also investigated by DSC. Compared with the linear block polymer, the corresponding miktoarm star polymer showed lower crystallization and melting temperatures and better phase separation.

中文翻译：

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基于丁烯二酮-马来酰亚胺双环加成的两亲性米克星型聚合物的合成和表征†

研究了一种基于sydnone-顺丁烯二酰亚胺双环加成（SMDC）的合成两亲miktoarm星型聚合物（MPEG）₂（PCL）₂的新方法，该方法使用“偶联到”，“由内向外”和“一锅法”进行。双“ 1，3-偶极环加合物”可通过“臂”马来酰亚胺封端的预聚物与“核” N之间的SMDC反应方便地获得-苯基亚砜。不管亚砜基和马来酰亚胺基团的摩尔比是多少，双环加成产物都不会改变。通过“偶合”方法合成的星形聚合物的多分散性最窄，“一锅法”最方便。SMDC反应极大地简化了合成过程，而且对miktoarm star聚合物的结构有很好的控制。所有聚合物的结构均通过¹ H NMR，FT-IR和GPC表征。DSC还研究了它们的热性能。与线性嵌段聚合物相比，相应的米克星形聚合物显示出较低的结晶和熔融温度以及更好的相分离。