A review: From the whole process of making thermal conductive polymer, the effective method of improving thermal conductivity

Abstract With the development of high power‐density electronic devices on smaller scales and emerging new energy vehicles, high thermal conductive materials have attracted more attention for better thermal management to adapt to various applications. By combining both the advantages of polymer materials and thermally conductive fillers, thermal conductive polymer composite materials are widely used in packaging and the protection of electronic devices for their mechanical robustness, high thermal conductivity, excellent insulation properties, heat resistance, and chemical resistance. In this review, first, the basic theory of heat conduction of polymer composites is discussed. Second, according to the classification of the composition of the thermal conductive polymer, the filled thermal conductive material is emphatically introduced. In this paper, the construction process of a thermal conductive network of polymer and composites is discussed from the perspective of processing. The simple construction of a thermal conductive network includes core‐shell structure, external force orientation, electrostatic spinning, electrostatic spraying, induced orientation, and vacuum‐assisted filtration. The three‐dimensional thermal conductivity network can be constructed using self‐assembly and template methods. From the above processing methods, this paper analyzes how to effectively improve thermal conductivity and achieve the goal of high thermal conductivity and excellent mechanical properties under low filling. After that, the contribution of filler and polymer modification to thermal conductivity is explained in detail. Finally, the future research direction of functionalization is prospected.