Poly(2-anisidine) Coating on Aluminum Alloy 5052: Electrosynthesis, Characterization and Its Corrosion Protection Properties in Marine Environment

Abstract

The electrosynthesis of poly(2-anisidine) on aluminum alloy 5052 (AA5052) surface was carried out by a galvanostatic method. Various constant current densities of 5, 10, 15 and 20 mA cm -2 at deposition times of 900, 1800, 2700 and 3600 s were applied to the formation of the coatings. The results showed that the current density of 15 mA cm -2 at the deposition time of 2700 s for the polymerization stage is the best condition for the synthesis of more compact and strongly adherent coatings. The coatings were characterized by FT-IR, UV-Vis and scanning emission microscopy (SEM) techniques. The corrosion protection performance of the coatings was investigated in 3.5% NaCl solution as a corrosive environment by the potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS). The corrosion current decreases significantly from 5.338 µAcm -2 for uncoated electrode to 0.004 µAcm -2 for coated electrode (under optimal conditions). The results clearly ascertain that the poly(2-anisidine) has outstanding potential to protect the AA5052 alloy against corrosion in a chloride environment.