A Study of Corrosion Resistance of PANI/Epoxy Resin Composite Conversion Film on Galvanized Sheet

Polyaniline synthesized with chemical oxidation of aniline, water-soluble epoxy resin, silane, and inorganic inhibitor were used to prepare a composite passivation solution, which was further applied to obtain a composite conversion film with good corrosive resistance. The corrosion resistance and surface morphology of the composite conversion on the galvanized sheet were studied with Tafel electrochemical polarization curves, electrochemical impedance, neutral salt spray test and atomic force microscopy. The results show that the polyanilineepoxy resin composite conversion film on the galvanized sheet surface is dense, with excellent corrosion resistance. The obtained composite passivation solution is a green product, and consequently has no harm to the environment. Moreover, the passivation process is relatively simple and the raw materials are inexpensive, which makes it promising in industrial application.