EFFECT OF INCORPORATING STARCH/SILICA COMPOUND FILLERS INTO UNCURED SSBR ON ITS DYNAMIC RHEOLOGICAL PROPERTIES

The dynamic rheological properties of a composite composed of solution-polymerized styrene butadiene rubber (SSBR) filled with starch/silica (SiO2) compound fillers were studied by means of temperature, frequency and strain sweeps, respectively, and the influence of the starch content in the compound fillers (SCCF) on the rheological behaviors was discussed. It is found from frequency sweeps that a maximum of loss tangent (tan delta) appears at 20 rad/s, which is independent of SCCF. G' of the composites decreases whereas tan delta and critical strain (gamma(c)) of Payne effect increase with increasing SCCF. The reasons for these are believed to be that both SiO2 and starch could form filler networks due to interaction of hydrogen bounding between them, and the interactions between SiO2 and SSBR are stronger than those between starch and SSBR. Moreover, increasing SCCF in the compound fillers is in favor of improving the stability of the filler networks. Furthermore, tand values at 0 degrees C and 60 degrees C representing the properties for the wet traction and the rolling resistance of SSBR composites respectively can be improved by partial replacing SiO2 with starch. However, the reinforcement effect of starch to SSBR is weaker than that of SiO2 due to starch agglomeration.