BN表面改性对BN/环氧树脂复合材料导热性能的影响

Effects of BN surface modification on thermal conductivity of BN/epoxy composites

采用十八烷基三甲基溴化铵(OTAB)阳离子表面活性剂对BN微米片进行有机化改性,研究了BN表面改性对BN/环氧树脂复合材料导热性能的影响。当OTAB浓度为0.6g·L^(-1)时,BN表面的OTAB吸附量接近饱和。BN表面改性提高了环氧树脂对BN的浸润性,降低了BN的导热系数。SEM观察及黏度测试结果表明:BN表面改性改善了BN/环氧树脂复合材料的界面性能及体系相容性。由于界面热阻的降低,改性BN/环氧树脂复合材料的导热系数高于未改性BN/环氧树脂复合材料,当BN填充量为30%(填料与树脂基体的质量比)时,改性BN/环氧树脂复合材料的导热系数为1.03W(m·K)^(-1),是未改性BN/环氧树脂导热系数(0.48 W(m·K)^(-1))的2.15倍。

Octadecyltrimethyl ammonium bromide（OTAB）was used as a cationic surfactant to modify micron BN platelets with an organic surface.The effects of BN surface modification on the thermal conductivity of BN/epoxy composites were studied.The adsorption of OTAB on BN surface is close to saturation at OTAB concentration of 0.6 g·L^-1.BN surface modification improves the wettability of epoxy resin on BN surface and decreases the thermal conductivity of BN.SEM and viscosity characterization show that the interfacial and compatible properties of BN/epoxy composites are improved by the surface modification of BN.Due to the decrease in interfacial thermal resistance,the thermal conductivity of the modified BN/epoxy composites is higher than original BN/epoxy composites.When the filler loading is 30%（mass ratio of filler to matrix resin）,the thermal conductivity of the modified BN/epoxy composite is 1.03 W（m·K）^-1,2.15 times of the thermal conductivity（0.48 W（m·K）^-1）of original BN/epoxy composites.