牺牲键主导的形状记忆高分子微观结构构筑与性能调控

Shape memory polymers (SMPs) as typical and general intelligent material gradually get the focus both in industrial and academic field. It had great applications and development prospects in drug delivery devices, self-healing materials, actuator and sensors, etc. SMPs dominated by sacrificial bonds have aroused wide attention due to their stimulation sensitivity, rapid response and controllable performance. This project focuses on investigating the shape memory property of amorphous diene elastomer and crystalline polymers, like polyisoprene or trans-1,4-polyisoprene. With the incorporation of sacrificial bonds into the molecular chains and the addition of nanofillers, the materials with excellent shape memory and self-healing properties can be prepared, which is expected with higher shape memory fixity and recovery ratios, and larger recovery stress simultaneously. The critical factors that affect the shape memory and self-healing properties will be systematically investigated, including the response speed and functional mechanism of sacrificial bonds, the surface chemical property of nanofillers and the external field function. The microstructure evolution of the materials under external field will be explored. The project aims to elucidate the shape memory mechanism on the different levels from molecules, congregated structures to interfacial interaction, and then provide fundamental theoretical guidance for research and development of shape memory polymeric composites with excellent performance.

作为智能高分子材料的重要分支，形状记忆高分子是学术与工业界研究与开发的热点，在智能储药设备、辅助自修复材料、智能驱动与感应器等领域具有重要的应用和发展前景。牺牲键主导的形状记忆材料因其刺激敏感、响应快速、性能可控，而被广泛关注。本项目拟针对非晶的二烯烃弹性体及一般结晶性聚合物，在分子链上引入牺牲键结构，并通过纳米复合改性，获得优异的形状记忆性能及良好的自修复功能，通过金属配位等牺牲键作用实现较高的形状固定率与回复率、更高的回复应力。进一步系统研究影响复合体系形状记忆及自修复性能的关键因素与作用机制，探讨牺牲键的反应速度、作用过程、填料的表面化学性质与加工外场的作用机理，通过研究外场作用下材料微观结构的演化机理，阐明影响材料形状记忆性能的分子机理、凝聚态结构、表面界面作用等机理，为高性能形状记忆高分子材料的开发提供理论指导。

作为智能高分子材料的重要分支，形状记忆高分子和自修复高分子是学术与工业界研究与开发的热点，在辅助自修复材料、智能驱动与感应等领域具有重要的应用和发展前景。牺牲键主导的形状记忆及自修复材料因其具有多种刺激敏感性、响应快速、性能可控等特点，而被广泛关注。本项目针对聚氨酯弹性体及一般结晶性高分子，藉由多嵌段共聚物的微相分离特点，提出了“相锁定动态化学键”的策略。通过在分子链上引入牺牲键结构，利用软、硬相区相分离将牺牲键锁定在硬段相区中，实现了在低于硬段相区Tg时，材料具有高的力学强度和使用性能，在高于硬段相区Tg时，动态化学键启动，材料实现自修复功能。进一步通过金属离子配位复合改性方法，实现所得材料的力学性能大大超过本体聚合物，得到超高力学性能的复合材料。并探讨了牺牲键的反应速度、作用过程、金属离子配位作用等影响因素和影响机理，为快速自修复高分子材料的研究和制备提供了基础理论指导。