Exploring the Application Potentials of Silatrane Coupling Agents in “Green Tire” Compounding

Herein, we report an optimized synthetic pathway and application of S-functionalized 3,7,10-trimethylsilatrane derivatives (Sil69, Sil266, and SilNXT) as silatrane coupling agents (SilCAs) dedicated to preparation of SSBR/BR/SiO2 composites. The tire performance of silatrane-based elastomers was compared to reference samples prepared with commercial triethoxysilyl compounds─Si 69, Si 266, and NXT. We discovered that the melting point of SilCAs can critically affect the degree of silica surface coverage during rubber mixing, as indicated by bound rubber content and the Payne effect. Furthermore, we proved vulcanization accelerating properties of the silatranyl moiety, as well as trialcoholamine through model reactions. The unique chemistry of the cage-shaped silica-binding group allowed us to achieve with SilNXT, 14% greater tensile strength, 8% higher wet traction, and comparable rolling resistance and abrasion resistance, in reference to NXT.