A novel fiber-reinforced silicone rubber composite with Al particles for enhanced dielectric and thermal properties

Aluminum (Al) reinforced silicone rubber (SR) composites were prepared, and the effects of the content, particle size, shape, and surface modification of Al particles on the dielectric properties and thermal conductivity of the Al/SR were investigated. Dielectric permittivity, dissipation factor and thermal conductivity of the Al/SR increase with increasing the filler content. The dissipation factors still remain at a low level at high filler content because of the insulating alumina shell on the surface of core Al. Decrease in particle size and surface modification of Al can increase the dielectric permittivity and thermal conductivity of the Al/SR composites. Compared with spherical Al/SR, the flaky Al/SR composites present higher dielectric permittivity and thermal conductivity. Dielectric permittivity and thermal conductivity of the Al/carbon fiber (CF)/SR composites reach 72.1 and 2.01W/m K at 75wt% of the total filler content, respectively, suggesting that the ternary composites has potential applications in electromechanical actuators because of their high dielectric permittivity and thermal conductivity but low dissipation factor, and good elasticity.