Mica as additional filler in SBR–silica compounds

The mechanical properties of mica–silica–SBR (styrene butadiene rubber) compositions were studied with special emphasis on fatigue resistance, using the Monsanto Fatigue-to-Failure Tester (FTFT) and De Mattia flexing machine. It was found that the addition of mica, in little concentrations, has a positive contribution to modulus, and does not change tensile strength, elongation at break and tear strength. Moreover, the addition of silane coupling agent enhances silica–rubber interactions, whereas the fatigue life of silica filled elastomeric compounds is adversely affected by the addition of mica. These behaviours were supported by scanning electron microscopy observations of the fracture surfaces.