Study On Thermal Conductive And Insulating Properties Of Silicone Rubber Materials

Silicone rubber materials have excellent properties such as high and low temperature resistance,chemical resistance,weather resistance,etc.,and are widely used in industrial and agricultural production and people's daily life.However,the thermal conductivity of silicone rubber materials is low,which limits its application in some fields.In this paper,the filling material is used to improve the thermal conductivity of the silicone rubber material,taking into account the insulation properties,mechanical properties and aging properties of the material.In order to obtain the silicone rubber composite with better comprehensive performance,the type and particle size of the filler are systematically studied in this paper.The influence of factors such as size and dosage on materials.Taking thermal conductivity,dielectric constant,hardness and tensile strength as the main indicators,the effects of filler type,size and dosage on the properties of silicone rubber materials were investigated.The results show:(1)The thermal conductivity of the rubber rubber material is significantly improved by the filling of alumina and magnesia,and with the increase of the amount of filler,the heat conduction network is formed inside the silicone rubber and gradually improved,and the thermal conductivity of the system increases;barium titanate and glass fiber powder It contributes a lot to the insulation properties of the composite.As the amount increases,the interfacial polarization between the filler and the matrix increases,and the dielectric constant of the material increases.(2)Under the same filling dosage,the small particle size filler has higher thermal conductivity and dielectric constant,because of its high volume fraction and large specific surface area,it is easier to disperse in the silicone rubber matrix;the addition of filler makes the material The hardness is increased,the tensile strength is lowered,and the mechanical properties are affected.(3)Using orthogonal test to optimize the optimal filling formula of silicone rubber material,namely,5 parts of 800 mesh magnesia,2 parts of nano-alumina,10 parts of barium titanate,and 5 parts of glass fiber powder.In pure silicone rubber,the thermal conductivity and dielectric constant are increased by 68.7%and 28.5%,respectively,and the thermal stability of the material can be improved.The effects of different temperature aging on the properties of silicone rubber materials were studied.The results show that:(1)At high temperatures,as time increases,the hardness of the silicone rubber material increases,while the tensile strength decreases,but the thermal and insulating properties of the material are hardly affected;the low temperature has little effect on the properties of the silicone rubber material.(2)After the introduction of Fe₂O₃ and Ce O₂,the hardness of the composite decreases,and as the amount increases,the tensile strength of the material decreases,and the thermal stability of the material is enhanced.The vulcanization process of the silicone rubber material is optimized,and the optimum process conditions are as follows:(1)Primary vulcanization:300?×60 s.(2)Primary vulcanization:200?×2h,the performance of various aspects of silicone rubber material after secondary vulcanization is significantly improved.(3)The optimum amount of vulcanizing agent is 0.8 part.