Effect of nano-silica surface-capped by bis[3-(triethoxysilyl)propyl] tetrasulfide on the cure behaviors, mechanical properties, swelling resistance and microstructure of styrene-butadiene rubber/acrylonitrile-butadiene rubber nanocomposites

In an in-situ surface modification method, nano-silica (NS) underwent treatment with bis[3-(triethoxysilyl)propyl]tetrasulfide, often referred to as TESPT, a commercially available SCA (silane coupling agent). This produced surface-functionalized NS, also known as modified nanosilica (mNS). The influence of using this mNS as a filler in styrene-butadiene rubber/acrylonitrile-butadiene rubber (SBR/NBR) composites was examined in this study. The results show that the silanol groups in TESPT form chemical connections with the surface of the NS, which significantly increases the rubber-matrix nanocomposite's curing efficiency and improves its mechanical properties. The reason for this enhancement is the in-situ surface modification of the NS by the SCA, which significantly raises the filler's miscibility and compatibility with the rubber matrix. The SBR/NBR nanocomposites filled with NS and mNS exhibited notable enhancements in tensile and tear strength, demonstrating improvements of 161% and 70%, respectively, in comparison to SBR/NBR vulcanizates.