流延法制备高热导率定向石墨/高分子复合片层材料

Preparation of oriented graphite/polymer composite sheets with high thermal conductivities by tape casting

摘要: 以天然鳞片石墨为原料，PVB为黏结剂，PEG和DBP混合物为增塑剂，通过流延工艺在室温下制备了定向排列的石墨/聚合物片层复合材料。系统分析了不同黏结剂用量和流延刀口高度下复合片层材料的定向排列状况，并探讨了定向排列程度对其热导率的影响。XRD和SEM的结果表明，石墨/聚合物复合片层材料显示了不同程度的定向排列。热导率测试结果表明，片层复合材料的热导率随着定向排列程度的提高而增大。通过优化黏结剂的用量和流延刀口高度制备了具有较高热导率的片层复合材料，其热导率最高可达490 W/(m · K)。

Abstract: Oriented graphite/polymer composite sheets were prepared using natural, crystalline flake graphites as raw materials, polyvinyl butyral as binders, polyethylene glycol and dibutyl phthalate as plasticizers by a tape-casting method at room temperature. The dependences of the binder contents and the blade heights on the orientation of the composite sheets were studied, and the effect of the orientation on the thermal conductivity was investigated. X-ray diffraction patterns and scanning electron microscope images showed that as-prepared samples showed different degrees of orientation. The thermal conductivity increased with the degree of orientation. The highest thermal conductivity of 490 W/(m · K) could be achieved by optimizing the binder contents and the blade heights.