Preparation and corrosion resistance study of two‐dimensional mica‐based composite coatings modified with UIO‐66 and polyethyleneimine

Abstract

AbstractNumerous challenges arise from metal corrosion, including economic loss, environmental pollution, and safety issues. Epoxy coatings, as a solution to metal corrosion problems, have been widely used worldwide. The improvement of epoxy coating performance is also a major focus of research. In this paper, we employed a hydrothermal method to load UIO‐66 crystals onto a two‐dimensional mica substrate, while simultaneously modifying the surface with polyethyleneimine (PEI) to enhance the compatibility of the filler in the epoxy coating. The water absorption and adhesion of the PMC‐UIO(4:1)/EP coating were optimized after the addition of the modified filler, with the adhesion strength of the PMC‐UIO(4:1)/EP coating improved to 8.28 MPa. In terms of electrochemical impedance spectroscopy, the PMC‐UIO(4:1)/EP coating manifested long‐lasting and superior corrosion resistance. Specifically, the electrochemical impedance modulus of this coating reached as high as 1011. Remarkably, even after immersion in a 3.5 wt% sodium chloride solution for 30 days, the coating maintained an impedance value order of magnitude at 109, which is unparalleled among all the composite coatings studied, demonstrating its exceptional corrosion resistance.