Improving the Thermal Conductivity of Natural Rubber Composites by Poly(catechol/polyamine) and Silane Surface Modification of Silicon Carbide

With the emergence of the 5G era, the high-precision operation of electronic devices usually results in high heat flux and increases the local heating power, seriously limiting their stability and service life. This paper presents a method for producing a thermally conductive filler by first noncovalently modifying silicon carbide (SiC) particle with poly(catechol/polyamine) (PCPA) and then covalently functionalizing it with 3-mercapto-propylethoxy-bis(tridecyl-pentaethoxy-siloxane) (Si747), which is labeled as SiC-PCPA-Si747. Next, the prepared SiC-PCPA-Si747 filler is added to the natural rubber (NR) matrix for producing SiC-PCPA-Si747/NR composites with high thermal conductivity (λ). The noncovalent modification of PCPA preserves the intrinsic λ of SiC, while the covalent functionalization with Si747 enhances the interfacial interaction between the filler and NR matrix. As a result of the reduced interfacial thermal resistance and the formation of high-efficiency heat conduction channels, the NR composite filled with 50 vol % SiC-PCPA-Si747 filler shows a λ value of 0.4980 W/(m·K), which is about 475% higher than that of pure NR (0.0866 W/(m·K)). In short, this method is cost-effective and feasible and can be used to fabricate polymeric composites with high λ that can meet the future demands of advanced electronic devices.