A new material, silica-filled rubber nanocomposite can be prepared from acid coagulation of the mixture of nanosilica slurry and natural rubber latex. By employing wet grinding process of conventional silica with grinding machine, nanosilica slurry can be formed. This efficient preparation method produces nanosilica slurry within a short time and in very large amount per batch. The selected modifying agents were silane coupling agents, polymer with low molecular weight and derivatives of polyethylene glycol. The effects of type and amount of treating agents on mechanical properties such as tensile strength, tear strength, elongation at break and abrasion resistance of natural rubber/silica nanocomposites were investigated. These coupling agents provided the dispersibility of silica nanoparticles in natural rubber. The silane coupling agents could form strong chemical bond with silanol groups of silica nanoparticles and double bonds in natural rubber. Moreover, the larger amount of treating agents in natural rubber/silica nanocomposite affected curing behavior by reducing both scorch time and cure time. Furthermore, the natural rubber/silica nanocomposites prepared from this method can decrease air pollution by using small amount or absence of silica powder in mixing process to prepare rubber compounding.
