Preparation of thermal interface material filled with micro-nano-composite particles into the polymer

With the rapid development of industrial production and micro-packing technology, the demand of thermal conductivity performance of materials becomes increasingly growing. Traditional metal materials have been unable to meet the use of certain special occasions. The thermal conductivity of pure polymer materials is poor, however, which can generally be changed by filling thermal conductive composite materials. This method to prepare high performance composite materials attracts more and more attention in recent years. The structures and performances of micro-nano core-shell composite particles can be designed. In this work, we synthesized a few core-shell composite particles with different sizes using sol-gel method, such as SiO₂/Al₂O₃, SiO₂/AlN, TiO₂/Al₂O₃, Al₂O₃/AlN. The composite particles were filled into epoxy resin. The thermal conductivity and mechanical properties of SiO₂/Al₂O₃ composite particles filled polymer composites are improved compared to SiO₂&Al₂O₃-physical mixing particles filled polymer composites. The results show that particles of core-shell structure improve the thermal conductivity coefficient of the thermal interface polymer materials and reduce the interfacial heat resistance. The storage modulus in glassy state and rubbery state of SiO₂/ Al₂O₃composite particles filled epoxy resin increased 15.4% and 85% compared to the 40wt% physical mixing particles filled epoxy resin and pure epoxy resin respectively. Furthermore, the bending strength of SiO₂/Al₂O₃ composite particles filled epoxy resin is 1.9% lower than that of the 40wt% physical mixing particles filled epoxy resin. The thermal conductivity coefficient of epoxy resin with content of 30wt% micro-nano particles of core-shell structure is 34.4% higher tha- that of pure epoxy resin, and 8.8% higher than that of 30wt% physical mixing particles filled epoxy resin composite. It indicated that the composite particles of core-shell structure have good heat conduction paths to improve the thermal conductivity of thermal interface polymer materials.