Xu Bowen, Yin Qichen, Su Chang, Cheng Jue, Zhang Junying, Zhao Jingbo
Key Laboratory of Carbon Fiber and Functional Polymers, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.
ACS Macro Lett. 2022 Apr 19;11(4):517-524. doi: 10.1021/acsmacrolett.2c00084. Epub 2022 Mar 25.
Nonisocyanate polyurethane (NIPU) has been extensively studied because of its sustainability potential. However, the low reactivity of five-membered cyclocarbonates with amines and the side reactions at higher temperatures always sacrifice the performance of NIPUs. In this work, a bisphenol-S cyclic thiocarbonate and different amino-terminated dimer-acid polyamides (DAPAs) were used to prepare nonisocyanate polythiourethanes (SPTU-DAs). Wherein bisphenol-S acts as a hard segment due to a π-π package, plentiful hydrogen bonds introduced by DAPA units induce crystallization and nanophase separation. They both endow the NIPUs with high mechanical performance. Meanwhile, active cyclic thiocarbonate, instead of cyclic carbonate, ensures rapid synthesis under mild conditions without side reactions. The experimental results of DSC, WAXD, and DMA confirmed the existence of crystallization of SPTU-DAs. The as-prepared thermoplastic polythiourethane has a maximum strength of more than 10 MPa, which is stronger than those of the cross-linked nonisocyanate polythiourethanes reported. It is of key significance to obtain the high performance of nonisocyanate polythiourethanes.
非异氰酸酯聚氨酯（NIPU）因其潜在的可持续性而受到广泛研究。然而，五元环碳酸酯与胺的低反应活性以及高温下的副反应总是会牺牲NIPU的性能。在这项工作中，使用双酚-S环状硫代碳酸酯和不同的氨基封端二聚酸聚酰胺（DAPA）来制备非异氰酸酯聚硫脲（SPTU-DAs）。其中，双酚-S由于π-π堆积而充当硬段，DAPA单元引入的大量氢键诱导结晶和纳米相分离。它们都赋予NIPU高机械性能。同时，活性环状硫代碳酸酯而非环状碳酸酯确保了在温和条件下快速合成且无副反应。DSC、WAXD和DMA的实验结果证实了SPTU-DAs结晶的存在。所制备的热塑性聚硫脲的最大强度超过10 MPa，比报道的交联非异氰酸酯聚硫脲更强。获得高性能的非异氰酸酯聚硫脲具有关键意义。
