PROGRESS IN ORGANIC COATINGS, cilt.76, ss.720-728, 2013 (SCI İndekslerine Giren Dergi)
This study reports corrosion protection behaviour of various metal cations electrodeposited onto polypyrrole (PPy) coated copper (Cu) electrode. Before electropolymerization of pyrrole, the Cu electrode was passivated in 0.1 M oxalic acid via cyclic voltammetry method. After the coating process, metal cation electrodeposition onto PPy coating was carried out in 10(-2) M CuCl2, ZnCl2, FeCl2 and NiCl2 solutions. Corrosion behaviour of uncoated, PPy and PPy vertical bar metal coated Cu electrodes was studied in 0.1 M H2SO4 solution by using potentiodynamic polarization, chronoamperometric and impedance spectroscopic measurements. Surface morphologies were examined by scanning electron microscope (SEM). All the electrochemical measurements were in good agreement showing that metal electrodeposited PPy coated Cu electrodes have a higher corrosion resistance. Furthermore, SEM results show that while all the samples have a homogeneous distribution of metal cations, zinc and nickel have a much better homogeneous distribution compared to copper and iron. It was found that the best corrosion protection is provided by PPy vertical bar Zn and PPy vertical bar Ni coatings and there is a significant increase in their polarization resistance with increasing amounts of electrodeposited cations. (c) 2013 Elsevier B.V. All rights reserved.