Polyaniline/polyvinyl chloride blended coatings for the corrosion protection of carbon steel

Abstract

Abstract This article presents the corrosion protection ability of blended polyaniline (PANI) and polyvinyl chloride (PVC) polymers applied on 1010 steel. The PANI/PVC blends, as well as pure PANI coatings, were fabricated via a casting method and characterized using infrared spectroscopy. Carbon steel substrates protected with the coatings were subjected to 40 day exposure tests in saline (3% NaCl) and acidic (0.1 M HCl) environments and subsequently analyzed using electrochemical methods Electron microscopy (SEM) and spectroscopic methods (EDS and XPS) were used to study the corroded surface of the 1010 steel underlying the protective coating, as well as the polymer coating itself. The PANI/PVC blends demonstrated superior corrosion protection in both environments as compared to pure PANI and pure PVC coatings. The PANI/PVC blend with a 1/1 proportion offered the most effective corrosion protection in acidic and saline environments based on high charge transfer resistance values and corrosion potential values that approach zero volts. The corrosion protection abilities of the blended coatings are attributed to a combination of barrier protection from the PVC and the formation of a protective oxide layer at the steel-to-polymer interface that is facilitated by the conductivity of PANI.