Preparation of graphene oxide-based polyaniline composites with synergistic anticorrosion effect for waterborne polyurethane anticorrosive coatings

Abstract In order to improve the service life of steel in harsh environment, functionalized graphene oxide (FGO)/polyaniline (PANIPA) nanocomposites with effective synergistic enhancement of corrosion resistance were prepared by in-situ redox polymerization in phytic acid (PA) solution. The structure and surface morphology of GO, FGO and FGO/PANIPA composites were characterized by Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), atomic force microscope (AFM), and ultraviolet-visible spectrophotometry (UV–vis). The corrosion protection property of FGO/PANIPA containing coating on mild steel was investigated by electrochemical impedance spectroscopy (EIS) technique in 3.5 % sodium chloride solution. The results confirmed that the WPU composite coating with FGO/PANIPA additive had a high corrosion resistance in the long term. Under the optimum conditions, where FGO accounted for 2.5 % of PANIPA, it had excellent long-term corrosion resistance due to the synergistic effect of the barrier effect of GO, the passivation mechanism of PANI and the Chelation of phytic acid in the coating.