取向碳化硅晶须硅橡胶复合材料导热性及绝缘性  

Research on thermal conductivity and insulation of oriented silicon carbide whisker silicone rubber composites

作　　者：于天骄 宋伟 冯景涛 彭修峰 宋文宏 YU Tianjiao;SONG Wei;FENG Jingtao;PENG Xiufeng;SONG Wenhong(Key Laboratory of Engineering Dielectric and Its Application,Ministry of Education,School of Electrical and Electronic Engineering,Harbin University of Science and Technology,Harbin 150086,China;Shanghai Baigao Polymer Material CO.,LTD.,Shanghai 201400,China)

机构地区：[1]哈尔滨理工大学电气与电子工程学院,工程电介质及其应用教育部重点实验室,哈尔滨150086 [2]上海拜高高分子材料有限公司,上海201400

出　　处：《复合材料学报》2024年第1期134-143,共10页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51541702,51607048)。

摘　　要：随着电子产品的集成密度和功率密度不断增加,优化热界面材料变的尤为重要。本文以一维碳化硅晶须(SiC_(w))为填料,硅橡胶为基体制备出导热硅橡胶复合材料,综合分析了复合材料的微观形貌、物相结构、导热性及绝缘性。首先通过共沉淀法制备出Fe_(3)O_(4)对SiC_(w)包覆的改性材料,其次将包覆Fe_(3)O_(4)的SiC_(w)在液体硅橡胶基体中分散均匀,最后将其置于恒稳磁场中完成晶须取向及基体固化。结果表明:SiC_(w)晶须表面包覆一层Fe_(3)O_(4)纳米颗粒且在硅橡胶基体中呈现取向排列,制备出SiC_(w)取向结构的硅橡胶复合材料。当取向SiC_(w)含量达到10wt%时,相比于纯硅橡胶导热系数可提升72%,比未取向10wt%SiC_(w)填充的高40%。相比于纯硅橡胶体积电阻率下降两个数量级,但仍然具有良好的绝缘性。通过COMSOL对SiC_(w)随机分散与取向排列的硅橡胶复合材料进行模拟仿真,仿真结果表明,含量10wt%的SiC_(w)可使硅橡胶导热系数提升60%,体积电阻率在10^(15)Ω∙cm以上,而10wt%取向SiC_(w)可使硅橡胶导热系数提升170%,体积电阻率在10^(14)Ω∙cm以上,与实验结果的趋势相一致。With the increasing integration density and power density of electronic products.It is particularly important to optimize the research of thermal interface materials.In this paper,one-dimensional silicon carbide whisker(SiC_(w))was used as filler and silicone rubber was used as matrix to prepare thermal conductive silicone rubber composites.The microstructure,phase structure,thermal conductivity and insulation of the composites were comprehensively analyzed.Firstly,the modified material of SiC_(w) coated by Fe_(3)O_(4) was prepared by coprecipitation method.Secondly,SiC_(w) coated with Fe_(3)O_(4) was evenly dispersed in the liquid silicone rubber matrix.Finally,it is placed in a constant magnetic field to complete whisker orientation and matrix curing.The results show that the surface of SiC_(w) whiskers is coated with Fe_(3)O_(4) nanoparticles,and they are oriented in the silicone rubber matrix.Silicone rubber composites with SiC_(w) oriented structure were prepared.When the oriented SiC_(w) reaches 10wt%,the thermal conductivity can be increased by 72%compared with pure silicone rubber,and it is 40%higher than that filled with non-oriented 10wt%SiC_(w).Compared with pure silicone rubber,the volume resistivity decreases by two orders of magnitude.But it still has good insulation.The silicone rubber composites with randomly dispersed and oriented SiC_(w) were simulated by COMSOL.The simulation results show that the thermal conductivity of silicone rubber can be improved by 60%with 10wt%SiC_(w).The volume resistivity is above 10^(15)Ω∙cm.However,10wt%oriented SiC_(w) can improve the thermal conductivity of silicone rubber by 170%and the volume resistivity is above 10^(14)Ω∙cm.It is consistent with the trend of experimental results.

关 键 词：硅橡胶 碳化硅晶须 取向 导热性 绝缘性 

分 类 号：TM211[一般工业技术—材料科学与工程] TB333[电气工程—电工理论与新技术]