Electrochemical investigations of polypyrrole aluminum flake coupling

Polypyrrole (PPy) Al flake composite (PAFC) was synthesized by chemical oxidation of pyrrole in the presence of Al flake and was used to formulate a corrosion inhibiting primer. The anticorrosion performance of the PAFC coating for AA 2024-T3 was evaluated by accelerated salt spray, scanning vibrating electrode technique (SVET), galvanic coupling measurement and electrochemical impedance spectroscopy (EIS). The PAFC primer showed an enhanced anticorrosion ability for AA 2024-T3 compared to the Al flake primer and provided cathodic protection for AA 2024-T3 as evidenced by galvanic coupling measurement. A possible corrosion protection mechanism provided by the PAFC and the role of PPy in the formulation were discussed.