CORROSION PROTECTION OF ALUMINUM-ALLOYS BY DOUBLE-STRAND POLYANILINE

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 a cidic salt solutions. Electrochemical impedance spectroscopy measureme nts show that the conducting polymer coated AA7075 alloy is highly res istant to corrosion. Mechanistic studies indicate that the conducting polymer is not a barrier polymer coating, but it chemically converts t he surface of the alloy to form a passive layer that protects the meta l from corrosion. The use of double-strand polyaniline facilitates a p aintable formulation for coating and provides good adhesion to the met al surface.