环氧树脂/氧化锌晶须/氮化硼导热绝缘复合材料的研究

以环氧树(脂EP)为基体,分别以氧化锌晶(须ZnOw)和ZnOw/氮化硼(BN)混合物为导热填料,制备了EP导热绝缘复合材料。研究了填料含量对复合材料导热性能、电绝缘性能及力学性能的影响,并利用扫描电镜对复合材料的断面形貌进行了观察。结果表明:随着导热填料含量的增大,复合材料的导热系数和介电常数增大,体积电阻率下降,而拉伸强度呈先增大后减小的趋势;在填料含量相同的情况下,EP/ZnOw/BN复合材料比EP/ZnOw复合材料具有更好的导热性能;当填料体积分数为15%时,EP/ZnOw/BN复合材料的热导率为1.06W/(mK)而,EP/ZnOw复合材料的热导率仅为0.98W/(mK)。

Study on Thermally Conductive and Electric-Insulating Epoxy/ZnOw/BN Composite

Thermally conductive and electric-insulating epoxy composites were prepared using zinc oxide whisker (ZnOw) and ZnOw/boron nitride (BN) blend as thermally conductive fillers respectively. The effects of the filler content on thermal conductivity, electric-insulating properties and mechanical properties of epoxy composite were investigated. The fracture surface of the composite was also observed by SEM. The results indicate that as the content of filler increases, the thermal conductivity and dielectric constant of the composite increases, while the volume resistivity decreases; besides, the tensile strength exhibits a tendency to increase firstly and then decrease; the thermal conductivity of epoxy/ZnOw/BN composite is higher than that of epoxy/ZnOw composite with the same filler content; when the volume fraction of fillers is 15%, the thermal conductivity of epoxy/ZnOw/BN composite is 1.06W/(m K), and that of epoxy/ZnOw composite is only 0.98W/(m K).