Stress relaxation behavior of magnetorheological elastomer: Experimental and modeling study

Magnetorheological elastomer is a smart magnetic-control polymer material. The aim of this work is to study the stress relaxation behavior of magnetorheological elastomer and expected to improve the anti-stress-relaxation property of magnetorheological elastomer. As a consequence, in this article, we developed an excellent magnetorheological elastomer based on the polyurethane/epoxy interpenetrating polymer networks matrix. The influences of constant strain level, matrix, magnetic field, and temperature on the stress relaxation behavior of magnetorheological elastomer were carefully measured. As expected, results suggested that the incorporation of interpenetrating polymer networks improved the anti-stress-relaxation property of magnetorheological elastomer. In addition, results revealed that the stress relaxation behavior of magnetorheological elastomer was highly dependent on magnetic field and temperature. In order to obtain a deeper insight into the influence mechanism of matrix and magnetic field, the power law model and stretched-exponential Kohlrausch equation were used to fit the experimental relaxation curves. Results showed that the experimental curves fitted well with these theoretical models. The influences of content of epoxy and magnetic field on fitting parameters were discussed, and relevant physical mechanism was proposed to explain it qualitatively.