基于二阶段固化的新型形状记忆环氧制备及组织调控研究

To solve the problem of easily shape changing and low strength emerged by shape memory polymer under space environment, the applicant put forward a new idea to synthesize a novel shape memory polymer epoxy which can be cured by the process of two-stage. The novel shape memory polymer epoxy can be cured for two separate stages under their different curing mechanism. Form molecular structure design perspective, the novel shape memory polymer epoxy have two kind of active groups and thus the process of curing can be controlled precisely. The controllable two-stage curing technology will be investigated. The effect of content and proportion of polymer molecule’s active groups on two-stage curing reaction activity and the microstructure of materials will also be discussed. Besides, the variation of polymer’s molecular structure, network topology and phase structure during different curing stages will also be studied. At the same time, we also focus on the research about reaction kinetics of ring opening of epoxides and double-bond radical polymerization during new polymer’s curing process in order to control the microstructure effectively. After that, the mapping relationship among polymer’s crosslinking network structure, microscopic phase structure and shape memory properties can be revealed. Based on all these studies, we can adjust shape memory polymer’s microscopic structure and optimize its properties at a more precise level. And eventually, lay the theoretical and practical foundation for the ultimate realization of SMP’s controllable two-stage curing.

针对形状记忆聚合物在空间环境下易变形、强度低的问题，本项目将二阶段固化的思路引入形状记忆环氧，拟合成一种新型的形状记忆聚合物，该聚合物可根据不同的固化机理进行二个阶段独立的固化。从分子结构设计角度出发，合成具有不同活性基团的聚合物，制备二阶段固化可控的新型形状记忆环氧。研究聚合物的分段固化控制技术，探讨聚合物分子结构中活性基团含量和比例对分段固化反应活性以及材料微观结构的影响；研究各固化阶段聚合物的分子结构、网络拓扑结构和相结构的变化规律；探索该聚合物固化过程中环氧开环反应和双键自由基聚合反应动力学，调控其组织结构；揭示不同固化阶段形状记忆环氧的共交联网络结构和微观相结构与其形状记忆性能的映射关系。在更加精细的层次上调节形状记忆环氧微观结构，优化聚合物性能，为最终实现形状记忆环氧的二阶段可控固化奠定理论和实践基础。

针对形状记忆聚合物在空间环境下易变形、强度低的问题，本项目提出了二阶段固化的思路对形状记忆聚合物组织结构进行有效调控。在地面进行一阶段固化制备出具有良好形状记忆性能的聚合物材料，在轨进行二阶段固化调增聚合物网络交联密度，赋予材料优异的耐热性、耐候性和力学稳定性。本项目主要研究内容包括：设计制备出热-热二阶段固化形状记忆环氧树脂体系、热-光二阶段固化形状记忆环氧树脂体系以及热-光二阶段固化聚丙烯酸酯体系，基于不同的固化机理进行二个阶段独立的固化，实现了不同阶段固化的可控性。确定了分段固化控制方法，建立了不同固化阶段树脂体系的动力学模型，研究了不同固化阶段聚合物分子间的反应历程，获得了各阶段反应程度和微观结构对形状记忆性能等的影响规律。该项目的研究为推动热固性形状记忆聚合物在空间展开结构中的应用奠定了基础。