Polypyrrole Film Doped with Corrosion-Inhibitors Electropolymerized on AA 1100

Polypyrrole films doped with dodecylbenzenesulfonate (PPy/DBS) and with oxy-anions tungstate (PPy/DBS/TUN) and vanadate (PPy/DBS/VAN) were potentiostatically electropolymerized on aluminum alloy 1100 (AA1100). The corrosion protection of these films was evaluated by the variation of the corrosion potential (ECORR) with the immersion time and by electrochemical impedance spectroscopy (EIS) measurements in 0.05 mol L-1 NaCl and 0.05 mol L-1 HCl solutions. The EIS measurements suggest that the tungstate and the vanadate play the role of a dopant and an inhibitor. The results presented here show that PPy/DBS/TUN and PPy/DBS/VANprovide a protective effect against the corrosion of the AA1100. It was shown that the oxyanions’ inhibitory action is different depending on the electrolyte pH. In an HCl solution PPy/DBS/TUN films improve protection against aluminum alloy’s corrosion. On the other hand, in a NaCl solution, PPy/DBS/VAN films and PPy/DBS/TUN films act as inhibitor, the former being more effective.