Effect of Precipitated Silica Physical Properties on Silicone Rubber Performance

Abstract

Abstract Nitrogen BET surface area is a highly accurate predictor of the physical performance of silica-filled and silica and carbon black-filled, cured organic rubber compounds. The effectiveness of predicting performance of a high-temperature-vulcanized, high-consistency silicone rubber, based on precipitated silica physical properties, is presented. Correlation and regression analyses were performed for twenty-five silica physical properties and fourteen silicone rubber performance characteristics. Silica properties studied included measurements of surface area, structure, impurities, particle size, pH and adsorbed moisture. Silicone rubber performance included measures of processing, curing, reinforcement, resiliency, stress whitening, color and clarity. The present study confirms that no single silica physical property can predict silicone rubber performance. A combination of surface area, oil absorption, particle size, pH, adsorbed moisture, residual sodium and/or residual salt can qualitatively predict the physical performance of high-temperature-vulcanized, high consistency, precipitated silica-filled silicone rubber.