热致相分离法调控三元导电高分子纳米复合材料的形态、结构与性能

Three kinds of conductive nano-particles, fullerenes, carbon nanotubes and graphenes will be selected as fillers and compounded with binary polymer blends with critical phase behavior.The matrix phase-separation will be used as a tool to control the dispersion of conductive fillers and the high-performance ternary conductive polymeric nanocomposites with low percolation thresholds will be prepared. In vitue of electron microscopic analysis and simultaneous measurement of rheological and conductive behaviors, the influence of nanofillers with different toplogical shapes on the evolution of condensed structure and phase-separation behaviors for the partiall miscible blend matrix will be investigated and the effect of different conductive fillers on stabilizing the droplets against flow induced coalescence will be also detected. Furthermore, the influence law of the morphology evolution for the blend matrix with time and temperature during phase-separation on the dispersion of conductive fillers in the nanocomposites will be explored to clarify the migration, aggregation of condunctive fillers in the blend matrix and the formation of conductive network. The correlation among the morphology, viscoelastic response and conductive properties of such conductive polymeric composites will be established to provide a theoretical guidance for the development and preparation of high performance conductive polymer nanocomposites.

以富勒烯（零维球状）、碳纳米管（一维管状）和石墨烯（二维层状）三种富勒碳族纳米导电粒子为填料，与具有临界相行为的二元共混物复合，以共混基体的相分离为手段有效调控导电填料分布，制备高性能、低渗流阈值的三元导电聚合物基纳米复合材料。借助流变响应与导电性能同步测试结合电子显微分析方法，考察不同拓扑形态的纳米填料对部分相容的共混物基体的凝聚态结构演变和相分离行为的影响，探明不同拓扑形态的导电填料对于稳定共混物基体相形态以抑制流动导致的基体分散相粗化的作用，寻求相分离过程中共混物基体相形态随时间和温度的演变对导电填料在共混物基体中分布状态的影响规律，阐明导电填料在聚合物共混基体中的迁移、聚集及网络形成过程，建立该类导电纳米复合材料的相形态-粘弹响应-导电性能之间的关联，为高性能导电高分子纳米复合材料的开发和制备提供理论指导。

项目采用纳米炭黑（零维球状）、碳纳米管（一维管状）和石墨烯（二维层状）三种碳族纳米导电粒子为填料，与具有临界相行为的二元共混物复合，以基体的相分离为手段有效调控导电填料分布，制备高性能、低渗流阈值的三元导电聚合物基复合材料。借助流变响应与导电性能同步测试结合电子显微分析方法，全面考察三类导电复合材料中的形态结构演化，研究纳米填料对部分相容的共混物基体的相行为的影响，探明纳米填料通过阻碍大分子链的终端流动行为来限制共混物基体的浓度涨落及相区粗化以稳定其相形态结构，发现导电填料在聚合物共混物基体相分离后受其与基体组分间的相互作用影响迁移至某一组分，再进一步在该富集相中聚集形成导电网络。因而导电填料的聚集过程主要受周围富集相中的大分子运动能力影响。在此基础上，初步建立该类导电复合材料的相形态-粘弹响应-导电性能之间的关联。基体相分离所导致导电填料的选择性分布，使复合材料由室温下的绝缘体转变为熔体中的导电材料，大幅降低材料的填料渗流阈值，故热致相分离可以作为有效手段调节填料在基体中的分布从而优化材料的导电性能。