Magnetorheological gel based on mineral oil and polystyrene-b-poly(ethene-co-butadiene)-b-polystyrene

Magnetorheological (MR) materials can have their properties reversibly altered by exposure to a magnetic field. Currently they can be divided into three categories: magnetorheological fluids (MRF), magnetorheological elastomer, and magnetorheological gel (MRG). MRFs present sedimentation problems inherent to the densities of their components. MRG are an alternative to MRF, but they still need to be further studied for their preparation. This study aims to prepare and evaluate the rheological behavior of eight MRG samples using iron carbonyl (HQ and OM) particles, SEBS copolymer and commercial mineral oil in different compositions. The samples were characterized by creep-recovery and angular frequency sweep, without magnetic field, and under magnetic fields (B) of 88 and 180 mT. The sample OM4 (7.47% vol/vol OM, 2.10% vol/vol KRT and 90.43% vol/vol mineral oil) showed a viscosity increase around ten thousand times under B = 180 mT, favoring a wide range of control. Through the results, the study concludes that the magnetorheological response of MRG was more affected by the gelatinous matrix (OIL + SEBS) than the particle size used. Even so, there are indications that the interparticle separation distance (IPS) in the polymer matrix of the material also influences the behavior of the sample.