Two-component room temperature vulcanized silicone-rubber (RTV2) properties modification: effect of aluminum three hydrate and nanosilica additions on the microstructure, electrical, and mechanical properties

Abstract

This study focused on investigating the effect of adding aluminum three hydrate (ATH) and various amounts of silica nanoparticles on electrical, mechanical, hydrophobicity, and flame retardancy properties of the two-component room temperature vulcanized silicone rubber (RTV2). Electrical results indicated the dielectric constant and dielectric loss of the composites were higher than net RTV2, also the composites showed higher volume resistance than net RTV2. However, adding SiO2 nanoparticles and ATH reduced the surface resistivity of the RTV2 from 16.71 (TΩ) to 15.66 (TΩ) in RTV2 + ATH and 15.79 (TΩ) in RTV2 + ATH + 3%SiO2 composites. Evaluation of mechanical properties showed that the elastic modulus in net RTV2 (0.00405 MPa) enhanced to 0.00484 MPa in RTV2 + ATH and 0.0098 MPa in RTV2 + ATH + 3%SiO2. Similarly, hardness of the composites showed a rising trend by increasing the filler content. Also, there was no improvement in hydrophobicity of the composites without SiO2 nanoparticles compared with net RTV2, but adding silica nanoparticles enhanced the hydrophobicity and contact angles in composites. An improvement in flame retardancy of the composite was obtained by a decrease in the torch affected (burned) zone when ATH and silica were incorporated.