UNIVERSAL PROPERTIES IN THE DYNAMICAL DEFORMATION OF FILLED RUBBERS

Starting from the observation that the filler particles in filled rubb ers form fractal clusters which are connected to each other, a theoret ical model is developed which establishes a connection between the amp litude dependence of the elastic deformation of filled rubbers and the structural properties of the filler. It is assumed that the elastic m odulus is dominated by the rigid filler network at very low strain, wh ereas at higher strain the rubber matrix provides the main contributio n because of cluster break-up. Within this model the exponent arising in an empirical description of the amplitude dependence is derived fro m the connectivity of the filler clusters.