基于IPN的环氧形状记忆聚合物本征导电功能化研究

Shape memory polymer is a novel smart material, and the general trend for its further development is to add functional characteristics appropriate to specific application environment. A new idea is suggested in this project that characteristic structures of conductive polymer and shape memory polymer are combined into one polymer to obtain intrinsic conducting shape memory polymer. This idea is carried out by half-interpenetrating polymer network (IPN) technology. In order to obtain an intrinsic semi-conducting shape memory polymer material with semi-IPN structure,conducting Polyaniline molecular chains and epoxy shape memory polymer network is connected effectively through dual-phase continuous,interpenetrating and forced compatibility by emulsion polymerization reaction and copolymerization reaction. Conductive properties of the epoxy intrinsic conducting shape memory polymer is improved significantly by adjusting density and doping level of large conducting Polyaniline molecular chains. The synergistic effect between conductivity property and shape memory effect is studied based on energy condition before and after shape changing of shape memory network and other characteristics, and the relationship between structure - properties is analysized. According to the aboves, mechanism of multi-function on shape memory effect - intrinsic conducting function is disclosured. This project suggests a novel method for conductive functionalization of shape memory polymer, and supplys theoretical guidance for other multi-functionalization of shape memory polymer.

形状记忆聚合物是一种新型智能材料，增加与具体应用环境相适应的功能特性已成为其进一步发展的大趋势。本项目提出将导电聚合物和形状记忆聚合物的特征结构结合于同一种材料中以获得本征导电的形状记忆聚合物的新思路，拟采用半互穿聚合物网络(IPN)技术来实现这一分子结构设计思想。通过乳液聚合和共聚合反应，使环氧形状记忆聚合物网络和导电聚苯胺大分子链形成双相连续、相互贯穿和强迫互容的有效连接，获得一种半IPN结构的本征半导体形状记忆聚合物。通过调控IPN结构中导电大分子链的聚集密度和掺杂程度来提高本征导电环氧形状记忆聚合物的电导率。基于形状记忆网络变形前后的能量状态等特征来研究导电和形状记忆两种功能之间的协同效应，分析材料的构效关系，从而揭示形状记忆聚合物本征导电功能化机理。本项目为形状记忆聚合物导电功能化研究提供了新途径，将为形状记忆聚合物其它功能化研究提供理论指导。

本项目提出将导电聚合物和形状记忆聚合物的特征结构结合于同一种材料中以获得本征导电的形状记忆聚合物的新思路，并采用互穿聚合物网络(IPN)技术来实现这一分子结构设计思想。. 采用乳液聚合-共聚合方法制备了不同掺杂处理的聚苯胺/环氧(PANI/EP)本征导电形状记忆聚合物；表征PANI/EP本征导电形状记忆聚合物的热性能、力学性能、导电性能、形状记忆效应和微观结构等；结果表明所制备的PANI/EP本征导电形状记忆聚合物均具有显著的形状记忆效应，且苯胺单体用量对形状记忆效应影响高于掺杂酸的种类；优先选用无机酸掺杂处理、增大苯胺单体用量，可促进材料的结晶行为、提高其导电能力及硬度，材料电导率最高为9.0×10-5S/cm。所制备的PANI/EP本征导电形状记忆聚合物中均存在结晶成分（DSC、XRD）、不存在相分离（DSC、SEM）、包含环氧和聚苯胺的特征官能团（IR）和特征元素(SEM)，由此可确定PANI/EP本征导电形状记忆聚合物中已形成分子级别互溶的IPN结构。. 采用溶胀聚合法分别制备了聚苯胺/乙烯-醋酸乙烯共聚物 (PANI/EVA)和聚苯胺/聚碳酸酯 (PANI/PC)两种本征导电形状记忆聚合物；表征材料的热性能、力学性能、导电性能、形状记忆效应和微观结构等；研究结果表明，所制备的溶胀聚合物均具有显著的形状记忆效应；溶胀处理时间的增加和温度的升高，都会降低PANI/EVA溶胀聚合物的电导率，PANI/PC本征导电形状记忆聚合物的电导率随着溶胀时间的延长先增大后降低，溶胀时间为6h时，两种溶胀聚合物的电导率均达到最高（PANI/EVA为1.3×10-4S/cm, PANI/PC为2.10×10-4S/cm）且载流子数量最多。导电聚苯胺的不影响两种溶胀聚合物的结晶行为；进一步通过DSC提供的相分离和结晶行为信息、红外光谱的官能团信息和扫描电镜的元素分析和形貌分析等结论，来分析推断在EVA中和PC材料表层形均成了IPN结构。采用市售聚苯胺和环氧形状记忆聚合物制备聚苯胺/环氧形状记忆聚合物复合材料，研究其掺杂处理、导电性能、电驱动、形状记忆效应和力学行为的变化规律，盐酸掺杂处理的复合材料的最高电导率为2×10-3S/cm。