刚玉粉对室温硫化导热硅橡胶性能的影响

Effect of corundum power on the performance of RTV silicone rubber.

以α ω -二羟基封端聚二甲基硅氧烷为基胶 ,刚玉粉为导热填料 ,制备了填充型室温硫化(RTV)导热硅橡胶。研究了刚玉粉的填充量、表面处理方式、粒径及不同粒径刚玉粉的配比对RTV导热硅橡胶性能的影响。结果表明 :随着刚玉粉用量的增加 ,RTV硅橡胶的导热系数增大 ,但力学性能降低 ,基料的粘度增大 ,工艺性能变差 ,刚玉粉的用量以 2 0 0份为宜 ;采用经表面处理的刚玉粉 ,可以改善其与基胶的相容性 ,提高RTV硅橡胶的导热性能 ;且采用硅烷偶联剂处理的刚玉粉还可提高RTV硅橡胶的力学性能 ;大粒径刚玉粉填充的RTV硅橡胶的导热性能优于小粒径刚玉粉填充的RTV硅橡胶 ,但力学性能下降 ;当填充量达到 2 0 0份后 ,二者导热性能的差距明显缩小 ;不同粒径刚玉粉并用可以提高RTV硅橡胶的导热性能 ,降低基料粘度 ,改善工艺性能 ;当大粒径与小粒径刚玉粉的质量比为 1 /3或 3 /5时 ,所得RTV导热硅橡胶的综合性能较好。

The room temperature vulcanized (RTV) silicone rubber with thermal conductibility was prepared by taking αω-dihydroxyl polydimethylsiloxane as basic gum and corundum power as heat conductive filler.The influence of the amount and surface treatment method and particle size of filler and proportion of corundum power of the different particles size to the properties of RTV silicone rubber were studied.The results showed that the heat conductive of the RTV silicone rubber increased with increasing the content of corundum power,but its mechanical properties declined,the viscosity of the filled compound increased,and the processability became worse.The preferable content of corundum power was 200 portions.The compatibility of corundum power with the filled compound and the heat-conductivity of RTV silicone rubber could be improved if adding surface-treated corundum power.Conundrum treated with silane coupling could also improve the mechanical properties of RTV silicone rubber.The heat conductivity of RTV silicone rubber filled with the conundrum with bigger grainsize was superior to that filled with the conundrum with smaller grainsize,but its mechanical properties decreased.When the filler level reached 200 portion,both showed very much similarly thermal conductivity.When adding the blend of the different grainsize corundum,the thermal conductivity and processing properties of RTV silicone rubber could improved,and the viscosity of the filled compound decline.When the mass ratio of between bigger grain size and smaller grain size corundum was 1/3 or 3/5,the combined properties of RTV heat conductive silicone rubber were good.