Sustainable Preparation of SiOC-SiC-C Hybrid Filler-Reinforced Epoxy Composites from Organosilicon Waste with Balanced Thermal Conductivity and Electrical Insulation

With the rapid development of 5G communication and high-power chips, thermal interface materials (TIMs) for electronic packaging struggle to balance high thermal conductivity, robust electrical insulation, and low cost. Here, we propose a sustainable strategy: converting solid waste from organosilicon monomer production into SiOC-SiC-C hybrid fillers through controlled pyrolysis, followed by compounding with epoxy resin to prepare high-performance TIMs. Systematic investigation of pyrolysis conditions revealed that treating the waste at 1300 °C for 2 h achieves complete phase separation. Amorphous SiOC decomposes into nano-β-SiC, turbostratic carbon, and insulating SiO2, forming a synergistic architecture. Nano-SiC acts as a thermally conductive phase, and carbon constructs a thermal bridge. The resulting composite exhibits a thermal conductivity of 0.76 W/(m·K) at 25 °C and 0.87W/(m·K) at 60 °C, which is 3.4-fold higher than that of pure epoxy. It also maintains a volume resistivity of 48.26 × 1010 Ω·cm. Infrared thermography confirms its superior thermal management capability, with faster heating/cooling rates compared to composites modified by other waste-derived fillers. This work demonstrates a scalable “waste-to-material” approach that valorizes organosilicon industry waste into high-performance TIMs. It offers a feasible technical route for sustainable electronic packaging and promotes a circular economy in the organosilicon industry.