High conductivity thermoelectric insulation composite silicone rubber prepared by carbon nanotubes and silicon carbide composite filler

Abstract Polymer based materials with high conductivity and electric insulation are widely used in new electronic fields as thermal interface material (TIM). In this work, firstly we prepared the mixed fillers of silicon carbide (SiC) and carbon nanotubes (CNT), and then used them to modify silicone rubber (SR) preparing composite SR. The experimental results of TGA showed that the composite silicone rubber had strong thermal stability, and the mass loss was only 5% until about 370°C. Besides, the thermal conductivity was significantly enhanced, which increased from 0.2 (pure SR) to 1.103 W·m −1 ·k −1 (composite SR containing 3wt%CNT and 20wt%SiC), the enhancement ratio arriving as high as 483.05%. In addition, the composite silicone rubber maintained (water contact angle above 90 °) hydrophobicity and electrical insulation (volume resistivity of composite SR with 3wt%CNT and 20wt%SiC up to 10 13 Ω·cm), which effectively prevent leakage risk and reduce voltage loss. Therefore, a small number of mixed fillers of SiC and CNT can effectively improve the combination properties of silicone rubber and provide more ideas for TIM.