Enhanced thermal conductivity for polydimethylsiloxane composites with core-shell CFs@SiC filler

With the increasing demand for thermal management materials in the highly integrated electronic area, high thermal conductive polymer composites are of great significance. Carbon fiber (CFs) is also considered to be an excellent choose when it is added into the polymer matrix as a filler owing to the high thermal conductivity. Nevertheless, the electrical conductivity of carbon fiber limits its application in the field of electronic packaging. In this work, a new type of CFs@SiC filler with core-shell structure was prepared by coating a layer of silicon carbide (SiC) on the surface of carbon fiber via chemical vapor deposition, and it was mixed with polydimethylsiloxane (PDMS) to fabricate a high thermal conductive and electric insulation thermal interface material (TIM). The thermal conductivity of PDMS composite with 55 wt% CFs@SiC filler reached 4.0 W m⁻¹ K⁻¹, which is 2402% higher than that of pure PDMS (0.16 W m⁻¹ K⁻¹), the measured tensile stress was 1.1 MPa and the volume resistivity of 15.1 Ω·cm. Combined with these superior properties, the PDMS composites have great potential for thermal management in electronic products.