Temperature effects of silane coupling on moisture treated silica surface

Moisture and temperature effects were investigated on silica/ (triethoxysilylpropyl) disulfide (TESPD)/carbon black (CB)/S-SBR compounds with respect to processability, vulcanization characteristics, physical properties, and alcohol residues. The moisture-treated compounds exhibited lower rates of viscous heat generation during mixing, lower discharging temperatures (drop temperatures), lower Mooney viscosities, shorter cure times (T-c -90), higher torque rises (M-H - M-L), less heat build ups (HBU), and equal or less alcohol residues than the control. As the drop temperatures of the compound were increased, decreased temperature differences between mixer sensor (set drop) and real (proven) temperatures, increased the scorch times (T-s-2), decreased the cure times (T-c-90), increased the tensile moduli, and decreased the alcohol residues remaining in the compound. The higher temperature drop compounds (160 and 176degreesC) exhibited no reversion behavior; however, the lower temperature (120 and 140degreesC) drop compounds exhibited marching behavior. The treatment of moisture on the silica surface influenced the hydrolysis reaction to the silane and improved coupling on the silica surface. (C) 2004 Wiley Periodicals, Inc.