Si_3N_4/SiC/环氧树脂纳米导热复合材料的制备

Preparation of silicon nitride/silicon carbide whisker/epoxy resin thermal conductive nanocomposites

以硅烷偶联剂KH-560改性的微米氮化硅/纳米碳化硅晶须Si3N4/SiCw为导热填料,浇注制备Si3N4/SiC/环氧树脂纳米导热复合材料。研究了环氧树脂种类、Si3N4/SiCw用量、复配比及表面改性对环氧树脂导3434热、力学和介电性能的影响。结果表明,环氧树脂的热导率随Si3N4/SiCw用量的增加而增大,当改性Si3N4/SiCw用3434量为50%[m(Si3N4)/m(SiCw)]=3/1时,环氧树脂的热导率为0.98W/(m·K);复合材料的介电常数随Si3N4/SiCw用量的增加而增大,而力学性能则先增加后降低。

The epoxy resin thermal conductive composites were prepared with micro-silicon nitride/nano-silicon carbide whisker （Si3N4/SiC） hybrid fillers modified with silane coupling agent of KH-560.The influence of epoxy resin type,content and ratio of Si3N4/SiC,and surface modification on the thermal conductivity,mechanical and dielectric properties of the epoxy resin were investigated.The thermal conductivity of the epoxy resin composites increased with increasing the content of Si3N4/SiC hybrid fillers.And the thermal conductivity coefficient was 0.98 W/mK for 50 wt% Si3N4/SiC hybrid fillers （mass fraction,Si3N4/SiC =3/1）.The dielectric constant of the epoxy resin composites increased with increasing the content of Si3N4/SiC hybrid fillers,however,the flexural and impact strength of the composites increased firstly,but decreased with excessive addition of Si3N4/SiC hybrid fillers.