碳包覆纳米铜颗粒/硫化硅橡胶导热复合材料的制备及性能

Preparation and Properties of Carbon Coated Copper/Room Temperature Vulcanized Silicone Rubber Thermal Conductive Composites

选用实验室自制的碳包覆纳米铜颗粒(Cu@C)为导热填料,以α,ω-二羟基聚二甲基硅氧烷为基体,采用机械共混法制备了碳包覆纳米铜颗粒/室温硫化(Cu@C/RTV)硅橡胶导热复合材料。通过透射电子显微镜、BET法、热导率测试仪、热重分析仪、万能材料试验机及邵氏硬度计等方法和手段,完成Cu@C纳米颗粒填料的微观形貌分析和比表面积测定,并研究了Cu@C填料在低填充量下(<30%)(质量分数,下同)对于Cu@C/RTV硅橡胶导复合材料热导率、热稳定性及力学性能的影响。结果表明,Cu@C纳米颗粒为球形、包覆型核壳结构,平均粒径在50 nm左右,其比表面积为69.66 m2/g。Cu@C/RTV硅橡胶导热复合材料的热导率随着Cu@C纳米颗粒填充量的增加而增大;填充量为30%时,复合材料的热导率可达2.41 W/m K;加入Cu@C纳米颗粒填料能够将RTV硅橡胶的热分解起始温度提高到422℃,并延缓其最终分解温度至625℃;随着Cu@C/RTV硅橡胶导热复合材料中Cu@C纳米颗粒填充量的增加,复合材料的拉伸强度和断裂伸长率呈下降趋势,而100%定伸应力和硬度则呈增大趋势。

By mechanical blending,the conductive filler,carbon coated copper（ Cu@C） nanoparticles prepared in lab,were added into α,ω-dihydroxydimethylpolysiloxa base rubber and then the carbon coated copper（ Cu@C） nanoparticles / the room temperature vulcanized（ RTV） silicone rubber conductive composites were prepared. The morphology and specific surface area of Cu@C nanoparticles,the effect of Cu@C fillers at low filling content（ 〈30%） on the thermal conductivity,thermal stability and mechanical properties of Cu@C / RTV silicone rubber conductive composites were investigated by transmission electron microscopy（ TEM）,BET method,thermal conductivity analyzer,thermo gravimetric analyzer（ TGA）,universal material testing machine and Shore durometer. The results show that Cu@C nanoparticles are nearly spherical in shape and possess good core-shell structure,and most of them are in size of 50 nm. The specific surface area of Cu@C nanoparticles is 69. 66 m2/ g. With increasing the Cu@C filler content,the thermal conductivity of the composites increases correspondingly and achieves 2. 41 W / mK when the filler content reaches 30%. Also,the initial and finish thermal decomposition temperature of Cu@C / RTV silicone rubber raise to 422 ℃ and 625 ℃ respectively with addition of Cu@C nanoparticles. Furthermore,the elongation at break and tensile strength of Cu@C /RTV silicone rubber decrease with the Cu@C filler content increasing,while the stress at 100% strain and hardness are increased.