Ge Hao, Shi Wencheng, He Chen, Feng Anchao, Thang San H
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China.
Center of Advanced Elastomer Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
Polymers (Basel). 2023 Apr 23;15(9):2002. doi: 10.3390/polym15092002.
Styrene-based thermoplastic elastomers (TPEs) demonstrate excellent overall performance and account for the largest industrial output. The traditional methods of preparation styrene-based thermoplastic elastomers mainly focused on anionic polymerization, and strict equipment conditions were required. In recent years, controlled/living radical polymerization (CRP) has developed rapidly, enabling the synthesis of polymers with various complex topologies while controlling their molecular weight. Herein, a series of core crosslinked star-shaped poly(styrene--isoprene--styrene)s (SISs) was synthesized for the first time via reversible addition-fragmentation chain transfer (RAFT) polymerization. Meanwhile, linear triblock SISs with a similar molecular weight were synthesized as a control. We achieved not only the controlled/living radical polymerization of isoprene but also investigated the factors influencing the star-forming process. By testing the mechanical and thermal properties and characterizing the microscopic fractional phase structure, we found that both the linear and star-shaped SISs possessed good tensile properties and a certain phase separation structure, demonstrating the characteristics of thermoplastic elastomers.
苯乙烯基热塑性弹性体（TPEs）具有优异的综合性能，在工业产量中占比最大。传统的苯乙烯基热塑性弹性体制备方法主要集中在阴离子聚合，需要严格的设备条件。近年来，可控/活性自由基聚合（CRP）发展迅速，能够在控制聚合物分子量的同时合成具有各种复杂拓扑结构的聚合物。在此，首次通过可逆加成-断裂链转移（RAFT）聚合合成了一系列核交联星形聚（苯乙烯-异戊二烯-苯乙烯）（SISs）。同时，合成了具有相似分子量的线性三嵌段SISs作为对照。我们不仅实现了异戊二烯的可控/活性自由基聚合，还研究了影响星形形成过程的因素。通过测试力学和热性能以及表征微观分数相结构，我们发现线性和星形SISs都具有良好的拉伸性能和一定的相分离结构，展现出热塑性弹性体的特性。
