Preparation and magneto-mechanical properties of 3D microporous magnetorheological foam

Magnetorheological (MR) materials with excellent magneto-mechanical properties have great application values in the field of vibration reduction and buffering. By combining the advantages of light weight and excellent energy absorption of porous polymer materials, the development of porous MR materials can improve the buffer performance of MR technology. In this paper, we proposed a one-step method for fabricating the 3D microporous MR foam based on polyurethane matrix. Micromorphology of MR foam character by scanning electron microscope shows the existence of a 3D network structure with embedded carbonyl iron particles (CIPs). The unique 3D microporous structure ensures the excellent magneto-mechanical properties of MR foam. The test results analyzed by a rheometer reveal that its compressive modulus and shear storage modulus enhanced significantly with the magnetic field. The influence factors such as CIP content, shear frequency, and shear strain have been systematically studied under the oscillating shear mode. It indicated that the MR foam exhibits obvious viscoelasticity, the dynamic modulus depends on the shear frequency and shear strain, and it has excellent magneto-mechanical properties. This work can provide a new technical solution for fabrication of MR porous materials for MR buffer technology.