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05~ 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。
关键词: 聚酰胺 / 碳化硅 / 钛酸钡 / 级配效应 / 导热系数 / 介电常数
Abstract:
With polyamide (PA6) as matrix,silicon nitride (SiC) as thermal conductive filer and barium titanate (BT) as the dielectric fier, aseries of composite materials are prepared by hot pressing method. The effect of different configurations with fillers of various particle sizes onthe thermal conductive and dielectrie properties of the materals are studied, The resuits show that when the filing amount is low the use othermal conductive filler of mixed particle size can produce a certain gradation elfect,thus improving the thermal conductivity of the compositematerial. 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. 7um and 3um at a proportion of4 : 1 when the total filing amount is 26% ,while the fillers with different particle size and diferent functiorare mixed .they could produce synergistic effect,further improving the thermal conductivity and obtaining beter dielectric properties at the samtime. When the filing amount of SiC is 20% and the BT is 20% ,the thermal conductivity of the composite material is 1. 1110 W/(m * K),thedielectric constant is 16 (100Hz),and the loss is kept at about 0.075 (100Hz).
Keywords: polyamide / silicon carbide / barium titanate / gradation effect / coefficient of thermal conductivity / dielectric constant