基于单晶相的双向可逆形状记忆高分子

Shape memory polymers typically exhibit only one way (irreversible) shape memory behavior. Recent progress has illustrated that a thermoset polymer with two distinct crystalline transitions can show two way (reversible) shape memory behavior. However, its operating mechanism remains unclear and polymers meeting the structure requirement are scarce, thus limiting its practical potential in terms of material selection and property tunability. This applicant has been working on shape memory polymers for years and recently made significant impacts on: discovery of new shape memory effect, mechanistic elucidation of polymer shape memory behaviors, exploration of novel applications of shape memory polymers. This proposed project aims to develop a two way shape memory system with a single crystalline transition, achieved by replacing the higher temperature crystalline phase with a high temperature amorphous phase. The advantage of the proposed system is that the amorphous phase has much better tunability (such as the transition temperature). As such, the proposed work will significantly widen the material selection and the system can serve as a better platform in elucidating the melecular mechanism of two way shape memory polymers. Building upon the investigation of reversible shape memory behaviors at the bulk level, this project will also explore such a behavior at the surface level, with the goal to estalish a solid base for future device applications.

形状记忆高分子通常只具备单向（不可逆）形状记忆行为。最新研究表明具有两个不同相转变温度的双结晶相热固性高分子可以表现出双向（可逆）形状记忆行为，然而其基本分子机理尚不明确，且符合这些结构要素的高分子种类较少，这些都限制此类材料的可选择性、性能的可调性，及其应用前景。申请者长期从事形状记忆高分子的研究工作，近期在新型记忆效应的开拓、形状记忆分子机理研究及性能调控、应用开发等方面取得了重要的进展。本项目拟在这些研究的基础上，利用一个高温无定形相来取代双结晶可逆形状记忆高分子中的高温结晶相，以此开拓只具有单结晶相的可逆形状记忆高分子。由于无定形相比结晶相具有更优越的可调性（例如热转变温度），此研究将大大提高可逆形状记忆高分子的材料选择性，并为阐明其分子机理提供优越的平台。在本体可逆形状记忆行为的研究基础上，本项目还将探索其表面形态可逆行为，为未来多功能器件的应用奠定更广泛的基础。

在本基金支持下成功探索了三类具有双向形状记忆行为的高分子网络：具有高温无定形相的单晶相双向形状记忆；基于肉桂酸光交联的单晶相双向形状记忆；具有热伸长冷收缩的反常双向形状记忆。实现了目前文献中最高可逆应变（40%）以及可逆形变的空间选择性控制，推动了双向形状记忆领域的发展。发表12篇通讯作者论文，其中5篇入选ESI高被引。