膨胀石墨-碳纤维/尼龙三元导热复合材料制备

以尼龙6（PA6）为基体，膨胀石墨（EG）和碳纤维（CF）作为导热填料，采用熔融共混法制备了EG/PA6、CF/PA6和CF-EG/PA6导热复合材料。重点研究当固定导热填料（CF和EG）填充量为40wt%时，CF与EG不同的填充比例对CF与EG的接触方式及CF-EG/PA6复合材料的导热性和力学性能的影响。结果表明，相比单一CF填充，EG的加入有利于CF-EG/PA6复合材料热导率的增加；CF:EG质量比是25:15时的EG-CF/PA6三元复合材料，热导率可以达到2.554 W/（m·K），是PA6的8倍，拉伸强度提高了125.34%，弯曲强度提高了119.8%，同时具有优异的耐热性。SEM结果表明，纤维状CF与蠕虫状EG片层在适当的填充比例下可以形成"面接触"的三维网络结构，这种三维网络结构不仅显著增大EG-CF/PA6复合材料的热导率，而且明显提高了其力学性能和耐热性能。为研制填充型导热高分子材料提供了一条新思路。 

Preparation of expanded graphite-carbon fiber/nylon ternary thermally conductive composites

With nylon 6 (PA6) as the matrix and carbon fiber (CF), expanded graphite (EG) as the thermal conductive filler, EG/PA6, CF/PA6 and CF-EG/PA6 thermal conductive composites were prepared by melt-mixing. Fixed the filling content of 40wt%, the effects of different ratios of CF to EG on the contact mode between CF and EG, and the thermal conductivity and mechanical properties of CF-EG/PA6 composites were studied. The results indicate that the addition of EG is beneficial to increase of the thermal conductivity of CF-EG/PA6 composites compared to single CF filling; When CF:EG mass ratio is 25:15, the thermal conductivity of CF-EG/PA6 composite reaches 2.554 W/(m·K), which is 7 times higher than that of PA6, the tensile strength is increased by 125.34%, the flexual strength is increased by 119.8%, and the heat resistance demonstrates excellent. The SEM results show that fibrous CF and worm-like EG can form a 3D network structure with "Terms contact" under the appropriate filling ratio. The 3D network structure not only significantly increases the thermal conductivity of CF-EG/PA6 composite, but also significantly improves the mechanical and thermal properties of the composite. It provides a new idea for the development of filled thermally conductive polymer materials.