Identification of stiffness and damping characteristics of magnetorheological elastomers due to immersion in seawater

Magnetorheological elastomer (MRE) materials are commonly used as vibration dampers in offshore structures. Therefore, it is urgent to investigate the degradation of this smart material because of seawater interaction. This work focuses on the immersion of MRE material in seawater, which alters its rheological and mechanical characteristics. Hence, it is important to investigate the impact of seawater immersion on the rheological characteristics of substances. This study contributes to the assessment of the stiffness and damping characteristics of MRE materials after exposure to seawater for one year. The MRE samples comprise MRE with a silicone matrix devoid of any Carbonyl Iron Particle (CIP) and MRE with 70% CIP, exhibiting both isotropic and anisotropic properties. Immersing the subject in seawater was carried out for one year. The study involved doing multiple tests, such as scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and rheological testing. The findings indicated that the samples underwent harm, erosion, and deterioration of their rheological characteristics during immersion. The stiffness values for isotropic MRE and anisotropic MRE decreased by 97% and 11%, respectively. Meanwhile, the deterioration of the damping characteristics values of isotropic MRE and anisotropic MRE was 96% and 14%, respectively.