Moisture absorption, desorption, and moisture-induced electrical performances of high-temperature vulcanized silicone rubber

This study focuses on the moisture absorption, moisture desorption, and moisture-induced electrical performances of high-temperature vulcanized (HTV) silicone rubber (SR). The influences of some parameters, such as filler (fumed silica and aluminum hydroxide) characteristics, relative humidity, temperature, tensile stress, and AC electric field, on moisture absorption/desorption are investigated. Results show that the tensile stress accelerates the moisture uptake and increases the saturated moisture absorption rate of HTV SR, and that the AC electric field has no significant influence on the moisture absorption of HTV SR. The dependencies of the dielectric constant, loss tangent, volume resistivity, AC breakdown strength, depolarization current, and polarization charge of HTV SR on the moisture absorption rate are examined. The depolarization current and the polarization charge as a whole increase with the increased moisture absorption rate of HTV SR.