Dynamic rheological behaviors of silica white (SiO2) filled solutionpolymerized styrene-butadiene rubber (SSBR) compounds were investigated

and application of the time-concentration superposition (TCS) principle to this system was verified.Master curves were obtained by shifting the frequency sweep rheological data of the filled compounds with respect to the unfilled SSBR.The master curves disclosed the existence of modulus plateaus in the low frequency region while the complex viscosity exhibited marked shearthinning.The master tanδ curves displayed maximum at a characteristic frequency that decreased with increasing filler volume fraction φ .The modulus and the frequency shift factors

AG and Aω

were introduced into the TCS principle on the basis of strain amplification effect due to the presence of rigid undeformable SiO2 particles as well as the constrained molecular motion of SSBR among the particles.Scaling relations were revealed to AG and Aω as a function of φ.However

the AG-φ relation did not follow the cluster-cluster aggregation (CCA) model that was usually suggested for particle suspensions or particle filled polymers.Influence of 3-octanoylthio-1-propyltriethoxysilane (NXT) as coupling agent to the dynamic rheological behaviors was also discussed.NXT did not influence the modulus plateaus and the shear-thinning index whereas it caused a reduction in characteristic relaxation time and marked increments in consistency and AG in comparison with the NXT-free compounds.