Sustainable and malleable polyurethane networks from castor oil and vanillin with tunable mechanical properties
Sustainable and malleable polyurethane networks from castor oil and vanillin with tunable mechanical properties
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DOI：
10.1016/j.indcrop.2021.114198
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发表时间：
2021-12
影响因子：
5.9
通讯作者：
D. Xie;De-Xin Lu;Xiao-Li Zhao;Yi-dong Li;J. Zeng
中科院分区：
文献类型：
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作者：
D. Xie;De-Xin Lu;Xiao-Li Zhao;Yi-dong Li;J. Zeng
蓖麻油（CSO）衍生聚氨酯（pu）由于其具有高交联密度和柔性网络骨干的永久交联结构而产生的低机械性能和不可再加工性受到限制。在这项研究中，我们报道了以香兰素衍生希夫碱（VSB）为多功能单体，由CSO和六亚甲基二异氰酸酯制备的可塑聚氨酯网络。一方面，具有多个刚性苯环和两个羟基的VSB作为结构改进剂来调节pu的网络刚度和交联密度，这使我们能够根据VSB的含量在广泛的范围内调整其机械性能，从软到韧和硬。另一方面，具有动态亚胺键的VSB在高温下通过亚胺交换反应，通过网络拓扑重排，为pu提供了包括延展性、热加工性和可回收性在内的玻璃聚合性能。因此，我们获得了具有可调机械性能（从弹性体到坚韧和硬塑料）的可延展性，可加工性和可回收性的cso衍生PU玻璃体，这将提高cso基PU的可行性和可持续性。
Castor oil (CSO)-derived polyurethanes (PUs) are limited by the low mechanical performance and non-reprocessability arisen from their permanently crosslinked structures with high crosslink density and flexible network backbone. In this study, we report malleable polyurethane networks prepared from CSO and hexamethylene diisocyanate with vanillin derived Schiff base (VSB) as a multifunctional monomer. On one hand, VSB with multiple rigid benzene rings and two hydroxyl groups works as a structure modifier to regulate network stiffness and crosslink density of the PUs, which allows us to tailor their mechanical properties over a broad range from soft to tough and hard depending on the content of VSB. On the other hand, VSB with dynamic imine bonds provides the PUs with vitrimeric properties including malleability, thermal processability, and recyclability via network topological rearrangement as a result of imine exchange reaction at elevated temperatures. Consequently, we achieved malleable, processable, and recyclable CSO-derived PU vitrimers with tunable mechanical properties (from elastomer to tough and hard plastics), which would improve the viability and sustainability of CSO-based PUs.