Effect of Silane on the Dispersion and Properties of Silica in Natural Rubber for Use in Tyre Tread Compounds

摘要

Synthetic silicas are used increasingly in tyre tread compounds. Their benefit to rubber properties is problematic unless a silane coupling agent is also used. The silane is added to silica often by in situ reaction. The effect of the coupling agent bis-(3-triethoxysilylpropyl) tetrasulphane (TESPT) on the properties of a sulphur-cured natural rubber compound containing a small amount of precipitated amorphous white silica was studied. TESPT was added to bind the silica to the rubber, and to prevent it from interfering with the reaction mechanism of the sulphur-cure system. This study showed that bound rubber, hardness, cyclic fatigue life, and cohesive tear strength were improved, whereas tensile strength, elongation at break, and stored energy density at rupture deteriorated with the addition of TESPT to the rubber. The inclusion of TESPT offered limited benefits to the silica dispersion and rubber properties.