Sun Xin, Ma Wen-Xuan, Zhang Jian-Xin, Wang Zheng-Yi, Wang Yang, Zhang Heng, Du Xiang-Yun, Liu Ji-Dong, Li Weili, Zhao Zheng-Bai
School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, PR China.
Tesa (Suzhou) Tape Technology Co., Ltd., Suzhou 215000, PR China.
Langmuir. 2024 Aug 6;40(31):16538-16548. doi: 10.1021/acs.langmuir.4c01981. Epub 2024 Jul 23.
The theory of heat conduction paths has been widely recognized and widely studied in the research about the thermal conductivity of thermal conductive polymer composites at present. Encapsulating polymer pellets with thermally conductive fillers and processing them into thermally conductive polymer composites is a simple and effective method for constructing heat conduction paths. It is meaningful to investigate the related heat conduction mechanism of this method. Otherwise, this approach can significantly preserve the performance of the polymer substrate, making it highly valuable for practical material applications. In this work, polyethylene-octene elastomer (POE) pellets were encapsulated with thermal conductive fillers by physical absorption. Subsequently, the composite films containing heat conduction paths were fabricated using the encapsulated POE pellets through a heating press. Alumina (AlO), boron nitride (BN), and alumina/boron nitride hybrid (AlO/BN) fillers were used to prepare AlO@POE, BN@POE, and BN/AlO@POE composite films to investigate the influence of filler shapes on heat conduction path construction. The influence of the constitute and density of heat conduction paths on the thermal conductivity of composite films was analyzed by infrared thermal imaging, finite element analysis, and thermal resistance theory in detail. Owing to the reserved good adhesion and flexibility of the POE substrate, the composite films could be directly used as thermal interface materials for chip cooling, which presented a good heat dissipation effect. Furthermore, a series of integrated composite materials were prepared by the combination of encapsulated pellets with various functional films (copper foil, aluminum foil, and graphite sheet) through a one-pot heating press, exhibiting a good electromagnetic shielding effect. The performance of the composites and the corresponding preparation method demonstrate the strong significance of this research for practical applications.
目前，在导热聚合物复合材料的热导率研究中，热传导路径理论已得到广泛认可和深入研究。用导热填料包覆聚合物颗粒并将其加工成导热聚合物复合材料是构建热传导路径的一种简单有效的方法。研究该方法的相关热传导机制具有重要意义。此外，这种方法能够显著保留聚合物基体的性能，使其在实际材料应用中具有很高的价值。在本工作中，通过物理吸附用导热填料包覆聚乙烯-辛烯弹性体（POE）颗粒。随后，使用包覆后的POE颗粒通过热压制备含热传导路径的复合薄膜。使用氧化铝（AlO）、氮化硼（BN）以及氧化铝/氮化硼混合（AlO/BN）填料制备AlO@POE、BN@POE和BN/AlO@POE复合薄膜，以研究填料形状对热传导路径构建的影响。通过红外热成像、有限元分析和热阻理论详细分析了热传导路径的组成和密度对复合薄膜热导率的影响。由于POE基体保留了良好的附着力和柔韧性，复合薄膜可直接用作芯片冷却的热界面材料，散热效果良好。此外，通过一锅法热压将包覆颗粒与各种功能薄膜（铜箔、铝箔和石墨片）结合制备了一系列集成复合材料，表现出良好的电磁屏蔽效果。复合材料的性能及相应制备方法表明了本研究对于实际应用具有重要意义。
