Electrochemically synthesized polypyrrole films as primer for protective coatings on carbon steel

The use of electrochemically synthesized polypyrrole (a conducting polymer) film is investigated as a primer for protective coating on carbon steel. It provides excellent adherence and corrosion resistance, and is more environment-friendly. Polypyrrole was galvanostatically synthesized on carbon steel, and epoxy paint top coat was applied on it. The corrosion performance was evaluated using salt spray test, Tafel plots, and electrochemical impedance spectroscopy. The performance was compared to that of a commercial zinc primer. These tests coherently demonstrate that the use of polypyrrole film inhibits corrosion better than a zinc primer in salt and acid environments.