以聚醚多元醇和甲苯二异氰酸酯为主要原料、硅烷偶联剂改性氮化铝(A1N)为填料制备了适用于特种车辆中央处理器的电源密封的聚氨酯导热绝缘密封胶,讨论了A1N的平均粒径和用量对该密封胶导热系数、绝缘性能以及力学性能的影响.结果表明,纳米级改性A1N在明显改善密封胶导热性的同时,可以保持材料优异的力学性能；当改性A1N质量分数达到48％时,聚氨酯导热绝缘密封胶的导热系数达到0.453 W/(m·K),表面电阻为1.5×109 Ω,体积电阻为2.6×1010 Ω,拉伸强度达到0.9 MPa,满足特种车辆中央处理器的电源密封要求.%With polyether polyol and toluene diisocynate as the main materials and modified aluminum nitride ( A1N ) as filler, the thermally conductive and electrically insulating polyurethane sealant which was used for special vehicle central centroller was produced. The effect of the average diameter size and the content of modified A1N on the thermal conductivity, insulating and mechanical properties of sealant was discussed. The result showed that modified A1N not only improved the thermal conductivity of sealant but also maintained the satisfying mechanical properties. When the mass content of modified A1N was 48% , the thermal conductivity of polyurethane sealant was 0. 453 W/( m·K) , the surface resistance was 1. 5 × 109Ω, the volume resistance was 2. 6 × 1010 Ω, with the tensile strength 0. 9 Mpa. This sealant could fit the central controller of special vehicles demand.
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