以多重氢键复合构筑自愈合型液晶弹性体

Due to the combined properties of ordering, fluidity and elasticity, liquid crystalline elastomers (LCEs) have a wide range of applications in functional and complex materials. However, the kind of materials are susceptible to damage and injure in the form of cracks in the process of the use, and this damage gives rise to their decrease of the mechanical property and lifetime. In this project, we try to import the self-healing feature into the LCEs inspired by nature, and expect this LCEs have the ability to spontaneously heal the injury and damage, which will improve the property and increase the lifetime in the using process. In order to realize the idea, a serial of novel LCEs will be reasonably designed through the introduction of the multiple hydrogen bonding. We will intend to design and prepare three kind of self-healing LCEs with different topological structures, namely, side-chain LCEs, rigid main-chain LCEs and block copolymer LCEs. Then, we are going to focus on the relationship of their chemical structures, topological structures, aggregated structures and their relative properties including self-healing character. Furthermore, the effect of external field such as force field, electric field and magnetic field on their mechanical and liquid crystalline properties and self-healing character will be investigated. We think that we can obtain the comprehensive and thorough understand the properties of the self-healing LCEs via the systematic studying on the design, synthesis, structure and properties. Based on such works, we will provide not only technological guidance but also theoretical basis for the preparation of new functional materials. Moreover, we wish we will obtain a kind of perspective and practicability self-healing LCEs at last.

液晶弹性体兼具有液晶的有序性、流动性和弹性体的高弹性，在功能材料和高级复合材料等领域具有广阔的应用前景。然而，该类材料在成型、加工和使用中均易产生局部微损伤，使得其力学性能和寿命将受到较大影响。在本项目中，我们将自愈合的功能引入该类液晶弹性体，期望能弥补该类材料在使用过程中的不足。本体系中，通过合理的分子设计将多重氢键的概念引入液晶弹性体中，设计并将制备侧链型、刚性主链型、嵌段型等多种不同拓扑结构的自愈合型液晶弹性体，研究其化学结构、拓扑结构和凝聚态结构的变化与液晶弹性体相关性能和愈合性能的之间的关系，考察外场作用对其弹性性能和自愈合性能及其他相关功能性质的影响。通过对该类液晶弹性体的分子设计、合成、结构与性能的系统全面的研究，从而对该类自愈合型液晶弹性做出更为深刻和全面的理解，为其进一步的功能材料的制备提供理论和实验依据，最终制备出具有应用前景的自愈合型液晶弹性体。

在本项目中，我们将含有液晶基元的单体与含有多重氢键作用位点的单体进行共聚，构筑了侧链型、刚性主链型、嵌段型等多种不同拓扑结构的自愈合型液晶弹性体。研究表明，该类弹性体相对传统的共价键交联方法，其制备方法更加简单、易行。可逆氢键的引入使得该类弹性体具有可塑性，相对于传统的化学交联体系有更好的加工性能，能多次成型，可制备成具有不同液晶取向和形状的样品。可逆氢键相互作用还赋予了该体系自愈合能力，有助于延长其使用寿命。该类基于多重氢键构筑的液晶弹性体具有自愈合性和多次加工性，可适用于不同功能和结构的器件的制备。我们还进一步研究了不同种类弹性体的化学结构、拓扑结构对其相行为和相结构的变化，考察了其结构与愈合性能、力学性能的之间的关系，进而为功能材料的制备提供理论和实验依据。相关实验结果已经在Chem. Commun.、Macromolecules、J. Mater. Chem. C等国际知名刊物上累计发表高影响力的SCI论文9篇，还有两篇审稿中，申请专利6项目，授权5项。与此同时，本课题组成员积极参加学术交流，先后13人次参加了6个学术会议，累计发表会议论文13篇。培养了1名博士生，培养了8名研究生，已经毕业的硕士研究生6人，2名研究生预计2018年7月毕业。同时，通过该项目的资助，有本科生12人在本实验室完成了毕业论文，目前本课题组在读硕士研究生10名，还有两名研究生在继续该课题的相关后续内容。