Abstract: A method of mixing crosslinkable elastomeric polymers and reinforcing fillers has been developed that yields significant improvements in physical properties compared to like polymers mixed by conventional methods. The method entails working a filler-polymer mixture at a temperature between the glass transition temperature and the liquid-liquid temperature of the uncrosslinked polymer to enhance filler integration. The mixture is then heated to a temperature greater than the flow temperature of the uncrosslinked polymer and worked so that air bubbles dispersed in the mixture are eliminated. The heating and cooling steps are repeated until the filler particles are thoroughly integrated and substantially all air bubbles are eliminated.