Electrochemical synthesis of nanostructure poly(3-aminobenzoic acid), polyaniline and their bilayers on 430SS and their corrosion protection performances

• Monolayer and bilayer poly(3-aminobenzoic acid)/polyaniline coatings have been successfully coated by cyclic voltammetry technique on the 430 stainless steel surface to obtain adhering coating.
• SEM images showed that the prepared coatings have a uniform, compact and nanostructure morphology.
• Cyclic voltammetric curves obtained shown electrochemical stability of prepared bilayer coating.
• Also, the EIS and polarization measurements illustrated that the bilayer coatings have better corrosion protection properties and the best corrosion protectability is related to PABA (10)/PANI (10) coating in 3.5% NaCl solution.

For the first time, adhesive and nanostructure monolayer and bilayer coatings of poly(3-aminobenzoic acid) (PABA) and polyaniline (PANI) have been electrodeposited on 430 stainless steel (430SS) from oxalic acid 0.3 M solution by cyclic voltammetry in order to protect 430SS against corrosion. The electrosynthezied coatings were characterized by cyclic voltammetry, UV–vis and FT-IR. The morphology and structure of the films were characterized by scanning electron microscopy (SEM). Corrosion protection performances of the coatings were evaluated in 3.5% NaCl solution by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The results of this study showed that monolayer and bilayer coatings have more ordered and uniform nanosize morphology and supplied significant protection against corrosion.