中文摘要：

用共沉淀法制备了具有超顺磁性Fe3O4-MWCNTs（多壁碳纳米管）复合粒子，加入环氧树脂（EP）中，在0.6 T的弱定磁场下固化成型。采用TEM研究其定向程度及分散性，并进行动态热机械分析、差热分析和导热率测试。结果表明，MWCNTs表面包覆了磁性Fe3O4纳米粒子，Fe3O4-MWCNTs复合物按照首尾衔接的方式沿着磁场方向定向排列。Fe3O4-MWCNTs/EP纳米复合材料表现出明显的各向异性，垂直于Fe3O4-MWCNTs轴向导热率低于平行方向的导热率，Fe3O4-MWCNTs的加入对于平行方向的导热率影响不大。Fe3O4-MWCNTs的加入使环氧树脂的储能模量变小，损耗模量变大，损耗因子均大于纯环氧树脂，表现出良好的阻尼性能。当Fe3O4-MWCNTs与EP质量比为0.3%时，损耗因子在20 ℃的温域内大于0.7，最高值达到1.16。

英文摘要：

Nanoparticles Fe3O4 were synthesized with co-precipitation method and coated on the surface of multi-walled carbon nanotubes （MWCNTs） to prepare the magnetic Fe3O4-MWCNTs hybrid. The magnetic Fe3O4-MWCNTs hybrid was aligned in the epoxy resin under weak magnetic field （0.6 T）. Alignment and dispersion of Fe3O4-MWCNTs were studied by transmission electron microscope （TEM）. Dynamic mechanical analysis （DMA）, differential scanning calorimetry （DSC） and thermal conductivity were tested. As a result, nanoparticles Fe3O4 are coated on the surface of MWCNTs, hybrids are aligned end-to-up under 0.6 T magnetic field. Thermal conductivity is anisotropy, with lower thermal conductivity in vertical direction, while Fe3O4-MWCNTs hybrid has little effect on the parallel thermal conductivity. With adding Fe3O4-MWCNTs hybrid into epoxy resin, storage modulus decreases and loss modulus increases. In the meantime, loss factors of nano Fe3O4-MWCNTs/epoxy composites are higher than those of the pure epoxy resin exihibiting good damping property. When the mass ratio of Fe3O4-MWCNTs hybrid to epxy resin is 0.3%, loss factor is more than 0.7 and up to 1.16 at about 20 ℃.