Research On The Effect Of Compound Addition Of Al₂O₃ And ZnO On Thermal Conductivity Of Epoxy Resin Composites

As the development of science and technology, especially the development of micro-electronic technique, the demand of thermal conductivity of packaging materials becomes higher and higher. Epoxy resin as polymer matrix materials attracts widely attention, because it has fine electrical insulation property, chemical stability and mechanical property. As the thermal conductivity of epoxy resin is very low, add in the epoxy resin with inorganic filler which has high thermal conductivity to ensure that the composites have high thermal conductivity and fine electrical insulation. In this paper, use the Al₂O₃ particles as the body to coat and grow the microstructure of ZnO, then to prepare core-shell structure of Zn O@Al₂O₃ and analyze the effect of microstructure of ZnO on the thermal conductivity of the composite. Use SEM, XRD and EDS to study the microstructure of ZnO, then fill in epoxy resin with prepared ZnO@Al₂O₃ to get the composite. Use three different coupling agents which are KH-560, KH-570 and KH-590 to treat tetrapod-like Zn O whiskers, then research the effect of treatment process on the interface bonding between ZnO whiskers and epoxy resin with different test methods such as activation index,contact angle and FT-IR analysis. Experiment results showed that:?1?When the pH of the solution was 11, the reaction temperature was 130?, the reaction time was 6h and the concentration of Zn2+ was 0.125mol/L, the coating results were the best while the Zn O@Al₂O₃ was prepared by hydrothermal method. At the same time, the microstructure of ZnO on the Al₂O₃ particles was rod-like, which was benefit of the establishment of thermal conductive network chain. The thermal conductivity of composite was 0.639W·?m·K?-1 which was highest when the volume filling rate was 10%.?2?When the pH of the solution was 5, the quality score of coupling agent was 1.5% and the hydrolysis time was 2h, the results of treatment were best while three different coupling agents were used to treat tetrapod-like Zn O whiskers. Then fill in epoxy with tetrapod-like ZnO whiskers whose volume fraction was 3% and the highest thermal conductivity was 0.569W·?m·K?-1 when ZnO whiskers were treated with KH-560.In this paper, in order to study the effect of different patterns of overlap, distances of overlap and thickness of interface layer on the establishment of thermal conductive network chain, models have been built to analyze the thermal simulation. Simulation results showed that: ZnO whiskers established consistent thermal conductive network chain in epoxy resin which greatly improved the thermal conductivity of composite. When the interface layer was existed between ZnO whiskers and epoxy resin and the thickness was 0.75?m, the thermal conductivity of compositewas highest which meant that the interface bonding between ZnO whiskers and epoxy resin was best.