Reinforcement of elastomers with in situ formed silica

Rubber nanocomposites were prepared with in situ formed silica (in situ silica), obtained through condensation of alcoxysilanes in the rubber medium. Compounds based on either isoprene or styrene-butadiene rubber were prepared with in situ and precipitated silicas, with experimental conditions traditionally applied in the industrial manufacturing. In situ silica gave rise to comparable stress-strain curves with better ultimate properties and, in particular, to remarkably lower compound hysteresis.