Corrosion protection of aluminum alloys by double-strand polyaniline

Abstract Corrosion protection of aluminum alloys was achieved by using a double-strand polyaniline as a surface conversion coating. The effectiveness of the coating was tested by salt-spray, and immersions in salt and acidic salt solutions. Electrochemical impedance spectroscopy measurements show that the conducting polymer coated AA7075 alloy is highly resistant to corrosion. Mechanistic studies indicate that the conducting polymer is not a barrier polymer coating, but it chemically converts the surface of the alloy to form a passive layer that protects the metal from corrosion. The use of double-strand polyaniline facilitates a paintable formulation for coating and provides good adhesion to the metal surface