Chemically synthesized polyaniline/polyvinyl chloride blended coatings for the corrosion protection of AA7075 aluminum alloy

Blended Polyaniline and Polyvinyl chloride coatings (thicknesses 5-30 μm) were used to protect AA7075-T6 aluminum in 3.5% NaCl solution. Electron microscopy revealed a well-defined structure with PCV predominating at the surface and constituting the bulk matrix; PANI formed agglomerates within the bulk and concentrated in a layer at the substrate/coating interface. Electrochemical tests demonstrated good performance over 15 days of exposure to saline solution; evidence includes high resistance to water uptake, low susceptibility to corrosion, and low corrosion current densities. Thick, smooth layers had the best performance and the blend outperforms a comparable pure PANI coating.