Preparation of Silica/Natural Rubber Latex Nanocomposite Emulsion and Its Application in Tire Puncture Sealing

Developing tire sealants that effectively combine rapid sealing and mechanical durability remains a key challenge. This study presents a novel, high-performance sealant based on a natural rubber latex (NRL) matrix reinforced with uniformly dispersed hydrophobic nano-silica (SiO2). A stable and homogeneous composite was achieved by employing sodium dodecylbenzene sulfonate (SDBS) as a surfactant and using ultrasonic processing. In simulated puncture tests, the optimized composite demonstrated superior performance, reducing the critical repair distance by approximately 3 km and the tire pressure loss by more than 75% compared to the reference samples. The repair mechanism was investigated through rheological analysis, electron microscopy, and mechanical testing. The enhanced performance correlates with electrical double-layer compression and particle aggregation and is accompanied by increased storage modulus and viscosity recovery that contribute to the sealing efficiency. These effects collectively increase the sealant’s storage modulus, enabling rapid sealing and effective resistance to shear under mechanical loading during tire rotation. This work provides both a practical formulation strategy and mechanistic insight for the development of next-generation, high-performance tire puncture sealant.