基于高分子熔体加工的导电微层复合材料制备及其各向异性研究

Constructing physically functional structures in polymer articles during melt processing is an important way to expand their application scope and enhance their added value. However, how to green and efficiently construct physically functional structures during processing is an urgent problem needed to be solved. In this project, a home-made “Extrusion-calendaring” machine will be employed to green and continuously fabricate alternating microlayered composites with anisotropically electrical conductivity. In view of the scientific problems concerning the building process of microlayers, the following work will be done: ①influence of conductive filler on the development of interface in incompatible polymer blends as well as their rheological properties; ②simulation the complex physical fields during melt extrusion and calendaring process, influence of rheological properties of each component on the phase behavior in the incompatible systems; ③ mechanisms for the evolution of alternating microlayers during “Extrusion-calendaring” process, the relationship between microlayers and mechanical, electrical properties; ④ the response of such anisotropically electrical conductive composites to external fields as well as their applications in electromagnetic shielding and heat conduction. This project will not only provide new ideas for the functional structure building via easy and green processing method, but also expand the functional application scope of common polymers. At the same time, this project will promote the added value of the common polymers, showing great significance both in academic theory and practical application.

在熔体成型加工过程中赋予高分子制品某种物理功能结构是拓展其应用领域、提升附加值的重要途径。然而，在此过程中如何高效绿色地构筑功能结构是亟待解决的问题。我们改装的高分子熔体“挤出-辊压”装置，能够绿色连续地制备具有交替微层特征的导电各向异性复合材料。基于此，针对微层结构在熔体成型加工过程中构筑的科学问题，拟开展如下工作：①导电填料对共连续不相容高分子共混体系界面的形成、发展以及流变性能的影响; ②模拟挤出和辊压过程中的物理场，在此基础上理解各组分流变特性对不相容共混体系相结构影响; ③“挤出-辊压”作用下导电交替微层结构的形成和演变机制，微层结构和力学性能、电性能的关系; ④导电各向异性微层复合材料对外场响应及其在电磁屏蔽、导热等领域的功能应用。本研究不但能为高分子材料功能结构的简单绿色制备提供新思路，而且能拓展通用高分子材料的功能应用并提升其附加值，具有一定的理论意义和应用前景。

导电各向异性是指电性能在材料中各个方向都不一样的特性。导电各向异性高分子复合材料已广泛应用于电子器件、光学元件、传感器、场发射器件、电子封装连接、散热器件等诸多领域，因此得到很多学者的关注。本项目的主要研究内容和研究结果如下：. （1）通过挤出-辊压方法制备了可控的润湿各向异性表面. HDPE微纤结构的样品表面具有高黏附性，并且蒸发过程不影响HDPE表面的润湿各向异性。可将具有HDPE微纤结构的样品作为“机械手臂”进行液滴转移工具，它表现出出色的液滴转移运输能力，有望应用于化学元素分析、生物监测和微反应等领域（ACS Applied Polymer Materials，2021, 3, 9, 4470-4477）.（2）通过挤出-辊压方法制备了一种微带结构的压电PVDF多孔片材.这种具有交替微带结构的PVDF片材可组装成压电传感器，它相对于实心PVDF具有较高的压电输出性能，较高的灵敏度和较短的响应时间。同时，它还具有优异的工作循环稳定性。结合自制的通信模块，该传感器可以通过无线传输远程监测运动员运动时的步频和步态（ACS Applied Polymer Materials，2021, 3, 2411-2419）。.（3）利用挤出-辊压制备热塑性高分子基“三明治”微层薄膜.此类“三明治”结构微层薄膜主要基于热塑性高分子材料来开发的，它们所展示出的功能性，为提升价格低廉的热塑性高分子材料的附加值提供了新思路。例如，此类薄膜在气敏响应行为（Sensors and Actuators B: 2021, 330,129370.）、透明和非透明转换智能窗（Chemical Engineering Journal, 2022,442, 136205.）、大面积自供电装置（Nano Energy, 2022, 103, 107771）等方面展示出了较大的应用潜力。.（4）其它成果.基于以上研究成果，获得河南省自然科学二等奖一项（郑国强排名第一，当年二等奖共8项）、出版著作一部（《Functionalized Processing for Thermoplastic Polymers》, ISBN: 978-1-64997-533-1, Scientific Research Publishing, Inc. 郑国强主编）、授权发明专利两项(郑国强为第一发明人)。