Bifunctional silane [bis(triethoxysilylpropyl)disulfide (TESPD)] was added to a silica-containing ethylene-propylene-diene terpolymer mold Compound, and its effects with respect to the vulcanization properties, processability, and physical properties were investigated. The addition of TESPD caused reduced heat generation during mixing, low minimum torque, low drop temperature, and low extrusion pressure buildup in the extruder. It also caused a high vulcanization torque, high torque rise, high torque maximum, and high elongational modulus. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 116: 237-244, 2010