Effect of the structure factors of some amine carbonic acids (ACA) and of their derivatives (ACAD) on corrosion and electrochemical parameters of St3 steel in the 0,1 N HCl solution

Issue 24(2) 2019
Pages 43-51

Т.А. Аliyev1, Yashar Hasanoglu2

1Nakchivan state University, Az-7000 Azerbaijan, Nakchivan city, university campus, NSU, chair of chemistry
2Aghri Ibrahimat chechen University, TC-38000 (04100) Turkey, Agri city, University Campus Agri, provice chair of A.İ.С of science

Keywords: amine carbonic acids, corrosion inhibitors, electrochemical impedance spectroscopy, Nyquist plots, protection effect

By various electrochemical methods, namely, methods of polarization curves and electrochemical impedance spectroscopy the influence of structural factors of some amino carboxylic acids (aliphatic monoamino carboxylic acids – Al - MAMCA: glycine, an alanine, leucine) and their derivatives (aliphatic monoamine dicarboxylic acids – Al - MADCA: asparagic acid, glutamic acid; aliphatic diamines monocarboxylic acid – Al - DAMCA: an arginine, with the general formula R-CH(NH2)-COOH) was studied on corrosion and electrochemical parameters of St3 steel in the system 0.1 N aqueous solution of HCl. It is established that studied compounds inhibit the corrosion processes of St3 steel in a varying degree. The particular regularities were found in the interrelation “Chemical structure of studied compounds – protective effect”. It was revealed that under the influence of some compounds the value Ecor is shifted to a negative side, values Ва, Rp, Rc are increased, and values icor and Сdl– are decreased. It was shown that by the type of action these inhibitors belong to mixed ones. By both methods it was established that on the effectiveness ACC and PACA are located in the following order: arginine › leucine › glutamic acid ≥ asparagic acid › alanine = glycine. It was shown that existence of several functional groups and heteroatoms (particularly, COOH, -NH2, -NH- et. all) in the molecules of ACA and PACA give them a tendency to adsorption on the surface of metal. It was suggested that interrelations “chemical structure of ACA and PACA – protective effect” - can be used for improvement of theoretical bases for selecting inhibitors.