Experiment And Theory Study On Heat Conductive Performance Of Composite Silicone Rubber

Thermal conductivity is one of the most important parameters characterizing thermal physical properties. Traditional heat conductive materials-metals have been limited in some special fields,for electric conductivity and erosion. Such as in the fields of electron and electric, electronic components and integrated circuit have much quantity of heat due to its miniaturization and micromation. All of this needs highly heat conductive and insulated materials to dissipate it in order to ensure the normal running of electronic equipments. Heat conductive silicone rubber not only possesses excellent thermal properties but also insulation and resistance to corrosion.Because the thermal conductivity of pure silicone rubber is poor, some heat conductive fillers are added into the pure silicone rubber so as to acquire its higher thermal conductivity. So composite silicone rubber filled with silicone carbide is studied by experiment methods and initial theory model in this paper. The results show that the thermal conductivities of composite will be increased with the increase of the amount of fillers. Furthermore, at a lower fraction of filler, the thermal conductivities of composite increase slowly, but the thermal conductivities of the composite increases obviously when the filling content surpasses a certain value. Besides silicone rubber filled with silicone carbide particle and whistler has better heat conductivities than that only filled with silicone carbide particle at a low filling content. Their thermal conductivities are close to each other with the further increase of the amount of fillers. The results also show that different coupling agents have different influences on the thermal conductivity of composites. Coupling agent (KH-602) has active impacts on the thermal conductivity. Moreover, the tensile strengthen and elongation at break of composite will be decreased, but Shore A hardness will be increased, with the increase of the amount of fillers. According to series-parallel connection principle, equivalent heat conductive coefficient equal law and thermal resistance network law, we initially study the thermal conductivity models and derivation of equation. On the basis of comparing equation with experiment results, we modify the equation to some extent.