高导热高介电BT/SiC/PA6复合材料的制备及性能研究

以聚酰胺(PA6)为基体,氮化硅(SiC)为导热填料,钛酸钡(BT)为介电填料,通过热压法制备出系列复合材料;研究了不同粒径填料的搭配对材料导热与介电性能的影响。结果表明:在填充量较低时,使用混合粒径导热填料能产生一定的级配效应,从而提高复合材料的导热性能。总填充量为26%时,以4∶1的比例,用粒径为0.5~0.7μm和3μm的SiC共同填充PA6,制备获得了最高导热系数为0.9198W/(m·K)的复合材料,而不同粒径、不同功能的混合功能填料还能产生协同效应,进一步提升材料的导热性能并使材料同时获得较好的介电性能,当SiC填充量为20%,BT填充量为20%时,复合材料的导热系数达到1.1110W/(m·K),介电常数到达16(100Hz),损耗保持在0.075(100Hz)左右。

Preparation and Property Research of BT/SiC/PA6 Composite Materials with High Thermal Conductivity and High Dielectric Properties

With polyamide(PA6)as matrix,silicon nitride(SiC)as thermal conductive filler and barium titanate(BT)as the dielectric filler,a series of composite materials are prepared by hot pressing method.The effect of different configurations with fillers of various particle sizes on the thermal conductive and dielectric properties of the materials are studied.The results show that when the filling amount is low,the use of thermal conductive filler of mixed particle size can produce a certain gradation effect,thus improving the thermal conductivity of the composite material.The composite material with the highest thermal conductivity of 0.9198 W/(m·K)is prepared by filling PA6 with SiC particles of 0.5-0.7μm and 3μm at a proportion of 4∶1 when the total filling amount is 26%,while the fillers with different particle size and different function are mixed,they could produce synergistic effect,further improving the thermal conductivity and obtaining better dielectric properties at the same time.When the filling amount of SiC is 20%and the BT is 20%,the thermal conductivity of the composite material is 1.1110 W/(m·K),the dielectric constant is 16(100 Hz),and the loss is kept at about 0.075(100 Hz).