基于氢键自组装芳杂环螺旋结构形状记忆树脂的构筑及作用机制

In order to solve the lower shape fix ratio，weaker shape recovery force, poorermechanical properties and heat resistance, and easier fatigue fracture during the shape memory cycle of the shape memory resins used in the aerospace space, a high-performance shape memory resin containing aromatic-heterocyclic helical structure self-assembled by hydrogen bonds will be constructed in this project. The molecular skeleton consisting of aromatic heterocycles structure confers excellent heat resistance and mechanical properties to its cured networks ; the change of helical conformation, destruction / reformation of hydrogen bonds and transformation of intramolecular / intermolecular hydrogen bonds are conducive to the improvement of the shape fix ratio, shape recovery ratio and recovery force of the shape memory process; the reversible change of the hydrogen bonds can repair the micro-damage in the curing network, and thus improve the fatigue resistance of the cured resin and prolong the service life. A series of shape memory resin systems containing helical structure self-assembled by amide hydrogen bonds will be designed, prepared and characterized. The relationship between structure and properties will be summarized and analyzed in detail, and the shape memory mechanism will be revealed. Therefore, this research project, which provides a novel means for design and development of high-performance shape memory polymer, takes on great significance in academic research and potential engineering application.

针对航空航天器使用的形状记忆树脂存在形状保持稳定性差、回复力不足、力学及耐热性能欠佳、在形状记忆循环过程中易出现疲劳断裂等共性关键问题，本项目从分子结构设计出发，拟构筑一类基于氢键自组装芳杂环螺旋结构为分子骨架的高性能形状记忆树脂。芳杂环网链骨架赋予树脂固化网络优异的耐热性和力学性能；螺旋构象的变化、氢键的解离/重建以及分子内/分子间氢键的转变等因素均有利于形状记忆过程中形变量、形变固定率、形变回复率及回复力的提升；另外，氢键的可逆动态变化能够对固化网络中的微损伤进行修复，从而提高树脂固化物的抗疲劳性能、延长使用寿命。将设计制备多种基于酰胺氢键自组装螺旋结构形状记忆树脂体系，对其耐热性能、力学性能、形状记忆性能进行系统表征，分析结构与性能的关系，揭示形状记忆机理及作用机制。本项目的开展为高性能形状记忆聚合物的设计开发提供一种崭新的思路，具有重要的理论研究意义和潜在的工程应用价值。

针对航空航天器使用的形状记忆树脂存在形状保持稳定性差、回复力不足、力学及耐热性能欠佳、在形状记忆循环过程中易出现疲劳断裂等共性关键问题，本项目从分子结构设计出发，拟构筑一类基于氢键自组装芳杂环螺旋结构为分子骨架的高性能形状记忆树脂。首先，采用分子动力学模拟分析了含扭曲结构、螺旋结构聚合物的结构参数及形成机制，讨论了扭曲结构、螺旋结构及氢键对聚合物的耐热性、力学性能及形状记忆性能的影响规律；其次，采用实验手段，设计合成了含酞Cardo结构环氧树脂、双马树脂，系统研究了非共平面扭曲结构对固化物形状记忆性能的影响机制。最后，探究了电加热驱动复合材料的形状记忆行为及定量表征。研究结果过表明向聚合物交联网络中引入芳杂环螺旋结构及酞Cardo扭曲结构，既保持了固化网络的耐热性及力学性能，又能提高了其形状记忆响应速度及形状记忆回复率，酚酞Cardo扭曲结构和芳杂环螺旋分子对形状记忆聚合物的热性能、力学性能、形状记忆性能产生协同作用。本项目的研究成果为高性能形状记忆聚合物的设计开发提供一种崭新的思路，具有重要的理论研究意义和潜在的工程应用价值。