Modified silane-coated carbonyl iron/natural rubber composite elastomer and its magnetorheological performance

To improve the dispersion of carbonyl iron (CI) particles in a rubbery medium, CI particles were pretreated with (3-aminopropyl) triethoxy silane (APTES), and processed with natural rubber for the fabrication of magnetorheological (MR) elastomers. In particular, for its anisotropic state, the MR elastomer sample was cured under a specific magnetic field to align the magnetic particles in the direction of the magnetic field. Scanning electron microscopy and mapping analysis were carried out to observe not only the coating of the CI particles with APTES but also the anisotropic state and the dispersion of CI particles in the MR elastomers. Viscoelastic experiments, such as strain amplitude and frequency sweep tests, were measured using a rotational rheometer under a range of applied magnetic fields. The CI/APTES-based MR elastomers demonstrated superior MR properties to the CI-based MR elastomer according to the rheological tests.