Alignment of anisotropic thermo-conductive filler, involving in-plane or out-of-plane orientation, is a significant strategy to extend thermal management applications of polymer materials, while the impact of the anisotropic thermal conductivity on thermal management performance is still lack of thoroughgoing study. Herein, a gradually thinning and re-assembling method is reported to fabricate in-plane and out-of-plane orientated polypropylene (PP)/graphite and PP/graphene composites, whose anisotropy could reach 8.37 and directional thermal conductivity achieves more than 4 W/m K. Based on this, a visualized study, supported by infrared imaging and finite simulation analysis, was carried out to investigate their thermal management performance for different applications. Results demonstrate that merely pursuing high directional thermal conductivity does not necessarily achieve optimal thermal management effect, it is equally important to customize oriented structure according to application scenarios. Our out-of-plane orientated polymer composites are proved beneficial to quick heat dispassion along vertical direction, making it perfect candidates as parallel thermal interface materials. However, when applied to scenarios where heat is generated from localized regions, this structure inevitably causes overheat due to the restricted heat flux, while the in-plane orientated composites show much better performance.

涉及面内或面外取向的各向异性导热填料的排列是扩展聚合物材料热管理应用的重要策略，而各向异性热导率对热管理性能的影响仍然缺乏全面性研究。在本文中，据报道，逐渐变薄和重新组装的方法可以制造面内和面外取向的聚丙烯（PP）/石墨和PP /石墨烯复合材料，其各向异性可以达到8.37，方向热导率达到4 W以上/ mK。在此基础上，进行了可视化研究，并辅以红外成像和有限模拟分析，以研究其在不同应用中的热管理性能。结果表明，仅追求高方向导热率并不一定能达到最佳的热管理效果，根据应用场景定制定向结构同样重要。经证明，我们的面外取向聚合物复合材料有利于沿垂直方向快速散热，使其成为平行热界面材料的理想之选。但是，当应用于局部区域产生热量的情况时，由于受限制的热通量，这种结构不可避免地会导致过热，而面内取向的复合材料则表现出更好的性能。经证明，我们的面外取向聚合物复合材料有利于沿垂直方向快速散热，使其成为平行热界面材料的理想之选。但是，当应用于局部区域产生热量的情况时，由于受限制的热通量，这种结构不可避免地会导致过热，而面内取向的复合材料则表现出更好的性能。经证明，我们的面外取向聚合物复合材料有利于沿垂直方向快速散热，使其成为平行热界面材料的理想之选。但是，当应用于局部区域产生热量的情况时，由于受限制的热通量，这种结构不可避免地会导致过热，而面内取向的复合材料则表现出更好的性能。