导电聚合物内嵌三维有序网络结构可控构筑机理及性能研究

Design and fabrication of an effective conductive network structure in conductive polymer composites(CPCS) are a key step to achieving its multi-functional development goals. However, the diversity and complexity of conductive network structures make it more difficult to mix conductive fillers into polymer-matrix materials. It is necessary to develop new manufacturing methods to promote the conductive network structure manufacturing technology. Therefore，the project puts forward a new method to build well organized three-dimensional network structures with carbon-based conductive particles to obtain high-performance conductive polymer composites. The traditionalconductive fillers and polymer base material blending process is decomposed into a micro jet printing forming process of many 2D filling area and an assembling process of layers. The impact behavior, the wetting behavior and the embedded behavior between carbon-based conductive particles such as graphite nanosheets (GN) and carbon black (CB) and polymer films are investigated. The micro-jet printing mechanism is revealed. The variation law of forming accuracy and forming process of essential features such as micro-jet printing points, lines, filling areas of one unit layer are studied. Carbon-based conductive particles are dispersed over a defined area and well organized three-dimensional network structures are built in a controlled way. The effect of different three-dimensional network structures on the electrical and mechanical properties of conductive polymer composite by computer simulation and experiments are investigated. Also the excellent function mechanism is discovered, and a comprehensive performance dynamic control model is built. If the project is successful, the results can provide the important theoretical basis and technical support for its development and application in multi-functions and devices.

设计制造有效的网络结构是实现导电聚合物多功能化发展目标的关键。然而，导电网络结构的多样性和复杂性增加了导电填料与聚合物基材的“复合”难度，需要开发新的方法推动其发展。为此，本项目提出一种面向高性能导电聚合物的碳基导电微粒三维有序网络结构可控构筑新方法，拟将传统的导电填料与聚合物基材共混过程设计成多个2D填充区微喷射打印成型过程和多个层单元组装过程。有待研究纳米石墨片/炭黑等导电微粒与聚合物薄膜基材的冲击、润湿和嵌合等交互作用行为，揭示微喷射打印成型机理；研究微喷射打印点、线、2D填充区等几何特征成形过程及精度变化规律，实现导电微粒分散区域精确控制、三维有序网络结构可控构建；通过建模仿真、试验研究分析三维有序网络结构对导电聚合物力学行为、电学行为的影响，揭示优异功能形成机理；建立导电聚合物综合性能动态调控模型。若获成功，将为导电聚合物多功能化、器件化发展和应用提供重要理论基础与技术支撑。

如何在基材内部快速有效地构筑三维导电网络结构是降低填充型导电聚合物的渗滤阀值并调控其力学性能和导电性能的重要途径之一，采取传统的工艺方法制备填充型导电聚合物时，难以对导电填料的分散过程及分散结构进行控制，难以实现多个技术目标的协同。本项目拟基于增材制造技术原理探索石墨、石墨烯等碳基导电填料的三维有序导电网络快速构筑新工艺，实现新型导电复合材料可控制备。研究内容如下：利用电学模拟仿真技术研究类蜂窝、类金刚石等三维有序网络结构导电通路形成过程，建立了新型导电复合材料电阻率计算模型；在制备石墨/酚醛树脂混合粉末基础上快速构筑了多孔石墨骨架，研究了提高多孔石墨骨架的电学、力学性能等后处理工艺措施，实现了多孔石墨骨架与酚醛树脂基体的复合，研究了类蜂窝三维有序网络结构变化对其力学性能和导电性能影响。在制备了石墨烯/聚乳酸复合微粒基础上，研究了石墨烯复合微粒喷射3D打印成型工艺和机理，研究了不同板前速度下单个石墨烯复合微粒、石墨烯复合微粒群冲击半固态酚醛树脂基体行为和结合机理，研究了石墨烯复合微粒喷射3D打印成型工艺参数、喷管结构对石墨烯复合微粒喷射速度及汇聚特性影响，快速构筑了石墨烯复合微粒导电网络。研究结果表明：在快速构筑多孔石墨骨架的基础上，通过两步法完全可以实现了新型导电复合材料的可控制备。在利用石墨烯复合微粒喷射打印构筑三维导电网络过程中，喷射成型压力、喷射距离以及喷嘴结构对复合微粒的喷射速度和分散范围均有较大影响，为了保证复合微粒完全嵌入半固化酚醛树脂基体内部，板前速度应达到600m/s以上，此时发生了绝热剪切现象，体系动能转化为内能，基体变软，石墨烯复合微粒可顺利嵌入其中。新工艺与传统的工艺方法相比，所制备的复合材料导电性能、力学性能稳定，不受外界环境温度的影响，同时通过多孔石墨骨架结构变化可实现其力学性能和电学性能主动调控，也可方便获得各项异性的导电复合材料。