Electropolymerization of m-aminophenol on mild steel and its corrosion protection effect

Poly-m-aminophenol (PMAP) films were synthesized using cyclic voltammetric (CV), chronoamperometric (CA) and chronopotentiometric (CP) methods in basic hydro-alcoholic medium on mild steel (MS). The structure and properties of these films were characterized by FTIR, UV–vis and scanning electron microscopy (SEM). SEM microphotographs reveal that the surface of MS was coated with PMAP films using CV, CP and CA methods. Some pinholes were seen in the SEM microphotograph of PMAP films prepared using CP method. The anti-corrosion behavior of PMAP films synthesized by CV, CA and CP has been investigated in 3.5% NaCl solution using potentiodynamic polarization and electrochemical impedance spectroscopy. The results show that PMAP films synthesized by CV and CA methods are much more effective in reducing the corrosion of MS than PMAP films synthesized by CP method. Corrosion performance of these films arises from the barrier effect for the diffusion of O2.