Preparation And Properties Of Thermal Conductive Additional Silicone Rubber Composite

Thermal management is more and more concerned as the improvement of the electronic components. The thermal conductive material with the property of low hardness and high thermal conductivity can play a good role in the thermal dissipation and shock absorption. In this paper, additional liquid silicone rubber and vinyl silicone oil filled with alumina, graphite nanosheet, carbon nanotube and aluminum hydroxide were investigated to be used as thermal conductive material. The effects of matrix, silicone oil, filler type, filler content, filler size and filler mixture on the structure, thermal conductivity, hardness, filler network, flame retardant property and volume resistivity were investigated in detail. Besides, we developed a new product and its property is better than Gap Pad VO manufactured by Bergquist. Our work can be summarized as followed:Graphite nanosheet/alumina/silicone rubber composites were prepared. Scanning electron microscope (SEM) was used to observe the dispersion of graphite nanosheet in SiR. Thermal conductivity and filler network were measured. The SEM imagines indicated that alumina can improve the dispersion of the graphite nanosheet in the matrix. The thermal conductivity analysis result showed that graphite nanosheet and alumina have a synergetic effect on the thermal conductivity improvement. We used RPA and SEM to study the mechanism of the synergetic effect. Besides, we used the Agari model to predict the P value.Carbon nanotube/alumina/silicone rubber composites were prepared. SEM was used to observe the morphology of the composites. Thermal conductivity, volume resistivity and filler network were measured. SEM imagines showed that the filler network was weak. Thermal conductivity analysis result showed that a small amount of carbon nanotube can improve the thermal conductivity of the composites. Carbon nanotube and alumina have a synergetic effect on the thermal conductivity improvement. Volume resistivity was dropped as the carbon nanotube loading was increased to2phr.An elastomeric thermal conductive pad was prepared using additional liquid silicone rubber. The processing method and the bubble problem were improved. Thermal conductivity is higher with the spherical alumina loading increasing. The silicone oil can not only reduce the flame retardant property but also the thermal conductivity of the composites. The flame retardant property is grade UL94V-0as the aluminum hydroxide loading excess50phr.An elastomeric thermal conductive pad was prepared using additional vinyl silicone oil. The hardness is bigger and the flame retardant property is better as the crosslinker loading was increased. Thermal conductivity of composites filled with flake alumina is higher than that filled with spherical alumina. A mixture of flake alumina and spherical had no influence on thermal conductivity. Increasing the nano alumina mixing ratio can improve the thermal conductivity. Thermal conductivity is1.001W/m.K as the small size alumina weight fraction is33%.