具有多重响应形状记忆和自修复两性离子聚合物的制备研究

Research on Multi-Responsive Shape Memory and Self-Healing Zwitterionic Polymer

以磺酸甜菜碱(SBMA)和2,3-二羟基甲基丙烯酸丙酯(GMMA)为共聚单体、硼酸为交联剂通过自由基聚合制备了一种两性离子聚合物,该聚合物表现出良好的温度、湿度多重响应形状记忆性能。氯化钠与磺酸甜菜碱之间静电屏蔽作用,降低形状记忆转变温度,使形变行为满足不同环境要求。动态硼酯键和可逆离子静电作用赋予了材料优异的自修复功能。本研究模拟两性离子聚合物作为伤口敷料通过湿度响应形状记忆行为实现对伤口位置紧密贴合的过程,为设计新型功能性伤口敷料提供新方法。

Sulfobetaine methacrylate(SBMA) is copolymerized with 2,3-dihydroxypropyl methacrylate(GMMA) in the presence of boric acid as crosslinking agent. The prepared material exhibits multi-stimuli responsive shape memory behaviors: it can rapidly recover to its initial shape upon heating,absorbing and moisture in humid environments. The shape memory effect can be well adjusted via incorporation of sodium chloride to induce the dissociation of electrostatic interactions between PSBMA chains, leading to reduced transition temperature and faster shape recovery rate. The dynamic nature of boron ester bonds and electrostatic interaction endows the material with effective and rapid self-healing ability. We also demonstrate the deployment process of the dressing that a sample with an initially circular shape can perfectly fit and tightly bound to the wound site after moisture-induced shape recovery. The proposed zwitterionic polymer can possibly extend the application scope of shape memory polymers and pave a new way for the design of wound dressings.