3‐Octanoylthio‐1‐propyltriethoxysilane (a new silane) grafted styrene butadiene rubber/ silica composites were prepared in the present work, where grafting weight percentage of the base rubber (0%, 2%, 4%, and 6%) and filler content of the composites (0, 5, 15, 35, and 50 phr) were varied to investigate dispersion of the filler in the rubber. A detailed quantitative study of morphology‐physical property relationship of the composites using dispersion degree parameter was carried out. Pronounced improvement of dispersion was observed with increasing grafting weight percentage of the base rubber. A mechanism of polymer to filler interaction was shown by Fourier transform infrared spectroscopy. The dispersion rate constant from the torque‐time curve increased with the grafting percentage. Bound rubber content and Payne effect measurement indicated improved rubber‐filler interaction for the grafted rubber compound. A relation between low strain modulus of the composites and grafting percentage was proposed. The nanoindentation studies gave further insight into the results. Other physico‐mechanical properties at different grafting weight percentages at particular filler loading (50 phr) and at different filler loadings at a particular grafting weight percentage (4%) were evaluated. The improved mechanical and dynamic mechanical properties with increasing grafting weight percentage are an indication that this methodology could be used in green tire application.

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Increasing the polymer‐filler interaction is a challenge to develop high performance rubber composites. In this study, a new blocked mercaptosilane (3‐Octanoylthio‐1‐propyltriethoxysilane) was used to increase the rubber‐silica interaction by modifying highly dispersible silica and fumed silica surface with this silane. A two‐step process was used for the modification. Successful hydrolysis and condensation reaction was proved by Fourier‐transform infrared spectroscopy. Grafting density and grafting percentage were determined using thermogravimetric analysis. The modified silica/rubber composites were compared with the compositions where silane was separately added during mixing. Dynamic modulus versus strain signatures demonstrated strong polymer‐filler interaction after functionalization of the silica surface. The composites containing modified silica demonstrated improved mechanical properties and abrasion resistance over the unmodified one, which were correlated with the dispersion index. Dynamic mechanical analysis showed 28% improvement of rolling resistance and 67% improvement of ice traction after modification. Amount of silane modified silica also varied in total filler loading for precipitated silica/rubber composites. Silica‐rubber composites, where hybrid silica structure (75/25 modified and pristine silica ratio) was used, displayed interesting property to fulfill the requirement of green tire composites. Such a finding can be extended to developing tires for energy efficient vehicles.

An interesting side-pathway leading to 1,3-dibromo-2-aryl-1H-indenes as opposed to isoquinoline N-oxides via NBS mediated bromination of 2-alkynylbenzaldoximes.

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