INFLUENCE OF END-FUNCTIONALIZED SOLUTION STYRENE-BUTADIENE RUBBER ON SILICA-FILLED VULCANIZATES WITH VARIOUS SILICA-SILANE SYSTEMS

摘要

We investigated how end-functionalized solution styrene-butadiene rubber (SSBR) affects the vulcanizate structures and the physical properties of silica-filled vulcanizates using non-functionalized and end-functionalized SSBRs with aminopropylalkoxysilane. Two silane agents were used. Triethoxy(octyl) silane was used as a covering agent, and bis-[3-(triethoxysilyl) propyl] disulfide was applied as a coupling agent. The effects of three different silica-silane systems with a covering agent (CV), a coupling agent (CP), or with no silane (NS) were analyzed. In the CV and NS systems, the cross-link densities induced by the polymer and curing system were similar with respect to the end-functionalization. Further, the cross-link densities induced by the silica-silane system were similar, regardless of the end-functionalization. However, the CP system exhibited similar cross-link densities, irrespective of functionalization. Both the coupling agent and end-functional group chemically bonded with the silanol groups of silica, thus competing with each other and affecting the vulcanizate structure. However, increasing the silica content decreased the effect of end-functionalization because the content of the coupling agent increased, and the end-functional group was less mobile than the coupling agent's alkoxy group.