Surface modification of silica by two-step method and properties of solution styrene butadiene rubber (SSBR) nanocomposites filled with modified silica

The traditional method for directly compounding rubber, silica, and bis(3-triethoxysilylpropyl)tetrasulfide (TESPT) by shear force, which we called it One-Step Method (OSM), results in a modification of uncertain mechanism: it is not clear whether chemisorption or physisorption is involved. In addition, OSM leads to large processing energy consumption (PEC). In view of these issues, we used a novel method (Two-Step Method, TSM) to investigate the modification process in detail. The TSM modification indicated that the TESPT hydrolyzed firstly to generate the silanol (Si–OH), and the silanol reacted with the hydroxyl groups on the surface of silica, which characterized by FTIR. The properties of modified silica were studied. Furthermore, the SSBR nanocomposites filled with modified silica by TSM and OSM were prepared and the properties comparisons were carried out. The obtained results exhibited the advantages of TSM, and also revealed that 8% TESPT amount was suitable than 12% and 15% TESPT amount.