Nedeljkovic Dragutin
College of Engineering and Technology, American University of the Middle East, Egaila 54200, Kuwait.
Polymers (Basel). 2021 Oct 12;13(20):3505. doi: 10.3390/polym13203505.
Functional polymers have been an important field of research in recent years. With the development of the controlled polymerization methods, block-copolymers of defined structures and properties could be obtained. In this paper, the possibility of the synthesis of the functional block-copolymer polystyrene-b-poly(2-(methoxyethoxy)ethyl methacrylate) was tested. The target was to prepare the polymer of the number average molecular weight (Mn) of approximately 120 that would contain 20-40% of poly(2-(methoxyethoxy)ethyl methacrylate) by mass and in which the polymer phases would be separated. The polymerization reactions were performed by three different mechanisms for the controlled polymerization-sequential anionic polymerization, atomic transfer radical polymerization and the combination of those two methods. In sequential anionic polymerization and in atomic transfer radical polymerization block-copolymers of the desired composition were obtained but with the Mn significantly lower than desired (up to 30). The polymerization of the block-copolymers of the higher Mn was unsuccessful, and the possible mechanisms for the unwanted side reactions are discussed. It is also concluded that combination of sequential anionic polymerization and atomic transfer radical polymerization is not suitable for this system as polystyrene macroinitiator cannot initiate the polymerization of poly(2-(methoxyethoxy)ethyl methacrylate).
功能聚合物近年来一直是一个重要的研究领域。随着可控聚合方法的发展,可以获得具有特定结构和性能的嵌段共聚物。本文测试了合成功能性嵌段共聚物聚苯乙烯-b-聚(甲基丙烯酸2-(甲氧基乙氧基)乙酯)的可能性。目标是制备数均分子量(Mn)约为120的聚合物,该聚合物按质量计含有20 - 40%的聚(甲基丙烯酸2-(甲氧基乙氧基)乙酯),且聚合物相将分离。聚合反应通过三种不同的可控聚合机制进行——顺序阴离子聚合、原子转移自由基聚合以及这两种方法的组合。在顺序阴离子聚合和原子转移自由基聚合中,获得了所需组成的嵌段共聚物,但Mn明显低于预期(高达30)。较高Mn的嵌段共聚物的聚合未成功,并讨论了产生不良副反应的可能机制。还得出结论,顺序阴离子聚合和原子转移自由基聚合的组合不适用于该体系,因为聚苯乙烯大分子引发剂不能引发聚(甲基丙烯酸2-(甲氧基乙氧基)乙酯)的聚合。