Understanding the reinforcing behaviors of polyaniline-modified carbonyl iron particles in magnetorheological elastomer based on polyurethane/epoxy resin IPNs matrix

In this study, in order to improve the interface between the carbonyl iron particles (CIPs) and polyurethane/epoxy resin IPNs matrix, we prepared a novel magnetorheological elastomer (MRE) containing polyaniline (PANI)-modified CIPs. Particles characterization results illustrate the changes of morphology, surface functional property, magnetic property and surface absorption behavior between the pure CIPs and PANI-modified CIPs. Scanning electron microscopy (SEM) analysis shows enhanced interfacial interaction of MRE. The test results of rheometer indicate that the MRE sample with PANI-modified CIPs exhibit larger storage modulus, smaller loss factor, and lower magnitude of Payne effect. The results also revealed that the MR performances, including the field-induced storage modulus and the storage modulus sensitivity, have also been promoted by improving the interfacial interaction between the CIPs and matrix. In addition, a modified phenomenological model is adopted to determine the influencing mechanism of Payne effect. The influences of interfacial interactions and magnetic field on the quantitative fitting parameters are discussed, and a relevant physical mechanism is proposed to qualitatively explain the mechanism.