Poly(O-anisidine) coatings on low carbon steel

Poly(O-anisidine) (POA) coatings have been synthesized on low carbon steel (LCS) substrate by electrochemical polymerization of O-anisidine monomer in aqueous solution of oxalic acid. These coatings were characterized by cyclic voltammetry (CV), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) measurements and scanning electron microscopy (SEM). It is observed that the polarization of the LCS substrate in an aqueous oxalic acid medium results into passivation of its surface via the formation of crystalline iron oxalate (FeC2O4, 2H2O) layer. In the presence of O-anisidine monomer, the electrochemical polymerization of O-anisidine takes place and uniform, strongly adherent dark green POA coating is obtained on the substrate. The molecular structure of the POA coating is similar to that of deposited on SnO2:F coated glass substrates.