Oriented flaky carbonyl iron and MoS₂/polyurethane composite with improved microwave absorption at thin thickness by shear force

Oriented flaky carbonyl iron and MoS₂/polyurethane (FCI & MoS₂/PU) composite with wide absorption bandwidth at thin thickness was successfully prepared by shear force. The morphology, electromagnetic, and microwave absorption properties in the frequency of 2.6–18 GHz of the composites were investigated. It was observed that the flaky FCI and MoS₂ particles became orienting along the tape-casting direction under shear force and parallel to each other. Compared with the un-oriented FCI & MoS₂/PU composite, the higher complex permittivity and permeability were obtained after oriented, which was superior in achieving improved microwave absorption performance at thin thickness. Wider absorption bandwidths of reflection loss (RL) values below − 5 dB were obtained at the thin thicknesses of 0.5–1.2 mm for the oriented FCI & MoS₂/PU composite. It suggests that the orientation by shear force is a promising approach for the preparation of materials with good microwave absorption property at thin thickness.