Preparation of Silica Reinforced Vinyltriethoxysilane Active Grafted Styrene Butadiene Rubber Composites

The vinyltriethoxysilane grafted styrene-butadiene rubber (SBR-g-VTES) was successfully synthesized using the ARGET-ATRP (electron transfer activated regenerative atom transfer radical polymerization) method in latex. Then, SBR-g-VTES/SiO₂ composites were prepared without a silane coupling agent. The effect of various reaction conditions on the grafted yield, properties, and morphology of SBR-g-VTES was investigated, and the influence of different silica amounts on the properties of SBR-g-VTES/SiO₂ composites was also discussed. The polymerization process conformed to the characteristics of active/controllable. The reaction condition SBR/CuBr₂/TPMA/VC (100.00/0.0010/0.0015/0.30) was chosen. The tensile strength of SBR-g-VTES reached 4.20 MPa, and the tear strength reached 40.00 MPa. When the amount of silica was 30 wt%, the bound rubber, tensile strength, tear strength, and hardness of SBR-g-VTES/SiO₂ composites reached 78%, 12.30 MPa, 97 MPa, and 91 shore A, respectively. The Akron abrasion is 0.03 cm³; a good balance between the wet sliding resistance and the low rolling resistance of the material can be realized. Meanwhile, SEM analysis results showed that the compatibility between silica and the rubber matrix was greatly improved by grafting VTES; SiO₂ was uniformly dispersed in the SBR matrix with a regular round shape.