Micromechanical analysis of an elastomer filled with particles organized in chain-like structure

Organization of iron filler particles inside an elastomer is obtained by curing the polymer in presence of a magnetic field. We have studied the effect of structuring the particles in chains on the quasistatic behavior in elongation in the absence of magnetic field. The effect of a coupling molecule between the surface of the particles and the elastomer is also analyzed. It is shown that the modulus of the first loading curve is strongly increased by structuring the particles, and also by the use of a coupling agent. Using an effective medium approach we well reproduce the experimental behavior of the elastic modulus and we deduce that a thick layer of elastomer is still present between the particles. A finite element calculation allows to distinguish between two modes of rupture at high strains, depending on the strength of the coupling between the particles and the matrix.