悬挂链增韧的可再加工热固性聚氨酯的合成  

Synthesis of Reprocessable Thermoset Polyurethane Toughened by Dangling Chains

作　　者：呼延辰熙 韩祥 王子币 王天雨 刘栋 陈飞 HUYAN Chenxi;HAN Xiang;WANG Zibi;WANG Tianyu;LIU Dong;CHEN Fei(School of Chemical Engineering and Technology,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学化学工程与技术学院,西安710049

出　　处：《功能高分子学报》2025年第1期71-77,共7页Journal of Functional Polymers

基　　金：国家重点研发项目(2022 YFF0503502);国家自然科学基金(22178278,22205174);西安交通大学基本科研业务费(xzy012024087)。

摘　　要：以4,4'-二环己基甲烷二异氰酸酯(HMDI)、1,2-己二醇(HDO)为反应单体进行预聚,丙三醇(GI)进行后交联,制备了一种具备微相分离的纯硬段热固性聚氨酯(HMDI-HDO-GI)。采用傅里叶变换红外光谱(FT-IR)、小角X射线散射(SAXS)和动态热机械分析(DMA)等对聚氨酯的微相结构和力学性能进行了详细研究。结果表明:通过调节含有悬挂链的HDO含量,可以调控HMDI-HDO-GI的微相分离结构,并赋予其高韧性。同时通过HMDI与HDO和GI反应过程中形成的大量氨基甲酸酯键与氢键可使交联网络实现再加工及自修复。该材料的微相分离结构使得纯硬段聚氨酯具有高达540.29 MPa的杨氏模量和63.89 MJ/m3的韧性,并且在160℃热压1 h的条件下可实现再加工。A pure hard-segmented thermosetting polyurethane with microphase separation was developed using 4,4'-dicyclohexylmethane diisocyanate(HMDI)and 1,2-hexanediol(HDO)as the reactive monomers for prepolymerization and glycerol(GI)for post-crosslinking.Its mechanical properties and microphase structure were investigated in detail.Through the post-crosslinking process of GI,the branched chain of HDO can act as a dangling chain to enhance the motility of the rigid main chain and act as a plasticizer.Meanwhile,based on the difference between the flexibility of the side chains and the rigid backbone of the crosslinked network,after the post-crosslinking of GI,the dangling chains can form domains,which form a micro-phase separation from the rigid main chain network,and thus enhance the toughness.By adjusting the proportion of HDO,the microphase-separated structure of thermoset polyurethanes can be modulated,thus conferring high toughness and allowing ductile fracture under uniaxial tensile conditions.In addition,by taking advantage of the dynamic behavior of the urethane bonds without introducing additional dynamic units,the large number of urethane bonds and hydrogen bonds formed by the reaction of HMDI with HDO and GI can confer reprocessing properties to the crosslinked network.The results show that the microphase-separated structure imparts a Young’s modulus of up to 540.29 MPa and a toughness of 63.89 MJ/m3 to the pure hard-segmented polyurethane, which can be reprocessed at 160 ℃ for 1 h.

关 键 词：聚氨酯 微相分离 韧性 再加工 悬挂链 

分 类 号：TQ433[化学工程]