A robust self-healing polyurethane elastomer: From H-bonds and stacking interactions to well-defined microphase morphology  

一种高强高韧自修复聚氨酯弹性体:通过多重氢键及其堆积作用实现微相结构的精确调控（英文）

作　　者：Cheng-Jie Fan Zi-Chun Huang Bei Li Wen-Xia Xiao En Zheng Ke-Ke Yang Yu-Zhong Wang 范诚杰;黄子纯;李蓓;肖文霞;郑恩;杨科珂;王玉忠(Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), State Key Laboratory of Polymer Materials Engineering,National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University)

机构地区：[1]Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), State Key Laboratory of Polymer Materials Engineering,National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University

出　　处：《Science China Materials》2019年第8期1188-1198,共11页中国科学（材料科学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(51773131,51811530149and 51721091);the International S&T Cooperation Project of Sichuan Province(2017HH0034)

摘　　要：Self-healing materials have attracted considerable attention because of their improved safety, lifetime, energy efficiency and environmental impact. Supramolecular interactions have been extensively considered in the field of self-healing materials due to their excellent reversibility and sensitive responsiveness to environmental stimuli. However,development of a polymeric material with good mechanical performance as well as self-healing capacity is very challenging. In this study, we report a robust self-healing polyurethane(PU) elastomer polypropylene glycol-2-amino-5-(2-hydroxyethyl)-6-methylpyrimidin-4-ol(PPG-mUPy) by integrating ureidopyrimidone(UPy) motifs with a PPG segment with a well-defined architecture and microphase morphology.To balance the self-healing capacity and mechanical performance, a thermal-triggered switch of H-bonding is introduced. The quadruple H-bonded UPy dimeric moieties in the backbone induce phase separation to form a hard domain as well as enable further aggregation into microcrystals by virtue of the stacking interactions, which are stable in ambient temperature. This feature endows the PU with high mechanical strength. Meanwhile, a high healing efficiency can be realized, when the reversibility of the H-bond was unlocked from the stacking at higher temperature. An optimized sample PPG1000-mUPy50%with a good balance of mechanical performance(20.62 MPa of tensile strength) and healing efficiency(93% in tensile strength) was achieved. This strategy will provide a new idea for developing robust self-healing polymers.自修复材料具有优异的使用安全性、更长的寿命、节能和对环境更低的影响等优势,因此受到研究者高度关注.超分子相互作用以其优异的可逆性和对环境刺激的快速响应性,在自修复材料中得到广泛应用.但如何通过合理的分子结构设计获得兼具优异机械性能和自修复能力的高分子材料仍是研究者面临的巨大挑战.本文通过将脲基嘧啶酮(UPy)基团引入到聚丙二醇(PPG)链段中,并精确调控其微相结构,得到了一种强韧的可自修复聚氨酯弹性体PPG-mUPy.聚合物链段中的UPy基团通过二聚形成四重氢键,不仅可以诱导相分离从而形成软硬段结构,还可通过π-π堆积相互作用,在环境温度下形成稳定的微晶,进一步提高聚氨酯材料的机械强度.此外,柔性PPG链段上氨基甲酸酯基团之间存在的弱氢键,赋予了材料超韧特性.通过温度调控启动微晶熔融,释放UPy的可逆特性,赋予材料优异的自修复性能.通过调控PPG链段长度、各组分含量及微观形态,得到综合性能最优样品PPG1000-mUPy50%,其拉伸强度可达20.62 MPa,强度修复效率可达93%.该方法为开发高强高韧自修复高分子材料提供了新的思路.

关 键 词：POLYURETHANE H-BONDS stacking interaction microphase morphology SELF-HEALING 

分 类 号：TQ334.1[化学工程—橡胶工业]