Temperature-Dependent Mechanical Properties and Model of Magnetorheological Elastomers

Magnetorheological elastomers (MREs) are composed of magnetizable particles (iron particles) and a soft rubberlike matrix. Their mechanical properties, including modulus and damping capability, depend on both an external magnetic field and an environmental temperature. To systematically investigate thetemperature-dependent mechanical properties, six different kinds of MREs samples based on a mixed rubber matrices (cis-polybutadiene rubber and natural rubber) and their mass ratios of BR and NR were 100:0, 80:20, 60:40, 40:60, 20:80, and 0:100, were fabricated in this study. The steady-state and dynamic mechanical properties of the samples were measured under different conditions by using a rheometer. The results revealed that storage modulus ( G ′) and loss modulus ( G ′′) of samples, which contained only cis-polybutadiene rubber (BR), decreased linearly with the temperature increment. However, the modulus of sample which contained much natural rubber (NR) showed different characteristic, and the relationships between stress and strain also exhibited different characteristics with different rubber matrix. An improved constitutive equation was developed to model these properties under different magnetic fields and temperatures. The comparison between modeling predicting results with experimental data demonstrated that the model can well-predict the modulus of MRE in different conditions.