'Effect of silane coupling agent blend system on structure and properties of silica/solution-polymerized butadiene-styrene rubber/ natural rubber composite'

Silica/solution-polymerized butadiene-styrene rubber (SSBR)/natural rubber (NR) compo-sites were prepared by mechanical mixing method with silane coupling agent, bis[3-(triethoxysilyl)propyl]tetrasulfide (Si 69) and 3-mercaptopropyl-ethyoxyl-di(tridecyl-pentamethoxy)-silane (Si 747), as modifier and the effect of types and addtion amounts of silane coupling agent on the microstructure, curing characteristics, processing performance, physical and mechanical performance, dynamic mechanical properties, tire performance, and the relationship between structure and performance of the composite. The results showed that compared with the composite just only modified by Si 69, the incorporation of Si 747 resulted in the scorch time and optimum curing time of the composite shorten signi-ficantly, and the curing rate improved gradually with the increase in the addition amount of Si 747; the synergistic modification of Si 69 and Si 747 made the physical and mechanical properties, tensile strength, resilience and modulus at 300% of the composite all reduced; when the addition amount of Si 747 increased, the apparent activation energy which was used to characterize the temperature dependence of storage modulus of the composite reduced gradually; the dispersion of silica in the composite improved significantly after the addition of Si 747; the loss factor (tan δ) of the composite modified by Si 747 alone at 0 ℃ increased significantly and tan δ at 60 ℃ decreased significantly; the rolling resistance of the tire improved gradually with the increase in the addition amount of Si 747.