碳质纳米填料在聚合物导热复合材料中的研究进展

Progress in Research of Carbon-Based Nanofillers Filled Polymer-Based Thermal Conductive Composites

碳质纳米粒子填充聚合物制备的导热复合材料,因其质量轻、比强度高、成本低和加工性能好等优势受到研究者关注。聚合物因其自身导热系数低,无法适应电子元件高功率化、高密度化和高集成化所产生的高热量散热要求。因此,研究开发高导热且力学性能优异的聚合物基导热复合材料对于电子产品的设计和扩展具有迫切的理论意义和实用价值。而目前聚合物基导热复合材料还存在一些不足,如碳质纳米填料含量较低时,导热能力不足;而其含量较高时,复合材料综合性能难以平衡。如何高效地构建有效导热通路以减少界面热阻是研究的难点和重点。鉴于此,文中不仅分析了碳质纳米填料和聚合物本征导热机理及聚合物基复合材料的导热机理,讨论碳质纳米填料本征结构以及在导热聚合物基复合材料中的聚集态结构对构建高通量导热通路的影响,而且提出近期或将来需要解决的关键问题。最后,就聚合物基导热复合材料未来的发展方向与趋势进行了展望。

Thermally conductive polymer composites filled with carbon nanoparticles are of high scientific and industrial significance due to the distinct featurs of light weight, high specific strength, low cost and favorable processability. However, the low thermal conductivity of polymer matrices largely thwarts their widespread applications especially in the fields of electronic components, mainly arising from the challenges in heat transfer caused by the high power, high density and high integration of materials. From the theoretical and practical points, it is therefore urgent to investigate polymer-based thermally conductive composites with a high thermal conductivity and excellent mechanical properties for the design and expansion of electronic products. Unfortunately, the exploitation of thermally conductive composites remains unsatisfying due to the inferior thermal conductivity in insufficient carbon-based filler contents and the poor balance between thermal and mechanical properties at high carbon-based filler contents. How to build effective thermal conducting paths to reduce the interface thermal resistance herein, the thermal conducting mechanisms of carbon nanofillers, polymers and carbon-based polymer composites were firstly analyzed. Then, the influence of the bulk structure of carbon nanoparticles and the assembly morphologies of carbon-based polymer composites on the construction of high-flux heat transfer pathways were discussed in details. The main focuses on enhancing the thermal conductivity were further given. Moreover, the development directions and trends of polymer-based thermally conductive composites were proposed.