The influence of the electron beam modification of a dual-phase filler on the dynamic mechanical properties of styrene-butadiene rubber (SBR) is investigated in the presence and absence of trimethylol propane triacrylate or triethoxysilylpropyltetrasulfide. Electron beam modification of the filler results in reduction of the tan 8 at 70degreesC, a parameter for rolling resistance, and an increase in the tan 5 at 0degreesC, a parameter for wet skid resistance of SBR vulcanizates. These modified fillers give significantly better overall performance in comparison with the control dual-phase filler. This variation in properties is explained in terms of filler parameters such as the filler structure that leads to rubber occlusion and filler networking. These results are further corroborated using the master curves obtained by the time-temperature superposition principle. (C) 2003 Wiley Periodicals, Inc.