Models for the impedance behavior of poly(2-mercaptobenzimidazole) protective coatings on copper-zinc alloys

摘要

This paper reports the in-situ electro polymerization of poly (2-Mercaptobenzimidazole) on metal substrates. We also report the study of the electrochemical and corrosion behavior of the coated electrode. The kinetics of the electro polymerization of 2-mercaptobenzimidazole (2-MBI) in alkalin methanolic medium was studied by various stationary and non-stationary techniques of polarization: the chronoamperometry, the cyclic voltammetry and the electrochemical spectroscopy of impedance. It was shown that three different quantities can be evaluated from impedance measurements for polymer protective coatings on metals in artificial solution at 3% of NaCl. The use of this technique for the determination of protective surface properties and their degradation with exposure time to corrosive environments was illustrated.