About the corrosion protection of copper by dicarboxylic acids

Some salts of dicarboxylic acids were investigated as corrosion inhibitors (CI) for copper in neutral chloride-containing solutions. One of them, sodium succinate, in borate buffer solution (pH 7.4) containing 10 mmol NaCl, decreases the value of passivation current density ip and increases the local depassivation potential E_ld. Mixture of alkenylsuccinic acids sodium salts (SAS) with the number of carbon atoms in the alkenyl n_C=12–15 (KAP-25) are more hydrophobic than sodium succinate and due to this show better protective properties. In the same solution, they decrease i_p at lower concentrations of Cinh and significantly increase E_ld. Another hydrophobic CI, sodium tridecanoate with n_C=12, showed better efficiency in stabilizing the passive state of copper. The passivation properties of the sodium oleate, well-known CI, also having a double bond, and SAS were shown to be close. In order to compare the efficiency of these CIs, accelerated corrosion tests were carried out in a humid atmosphere with daily condensation of moisture on copper samples passivated in aqueous solutions of SAS, sodium oleate or sodium tridecanoate. It was shown that in the absence of chlorides, the best protective properties were shown by the SAS solution, but if after passivation of copper samples they were immersed for 10 seconds in water containing 1 g/L NaCl, the protective properties of the SAS became weaker than those of sodium tridecanoate. To enhance the protection of copper by AS anions in the presence of chlorides, additives of 2-mercaptobenzothiazole (2-MBT), capable of forming hard-soluble complexes with Cu(I), were used. Studies were carried out by electrochemical impedance spectroscopy (EIS) and by corrosion tests. It was shown that in the 3.5% NaCl solution containing only SAS, the obtained hodographs were described by the equivalent electrical scheme of Randles-Erschler, and in the presence of 2-MBT the R_c–C_c chain characterizing the properties of the formed complex layer was added. Comparison of the calculated R_c values made it possible to identify the best CI compositions. It was shown that small additions of 2-MBT significantly enhance the protective effect of SAS, and a synergistic effect is observed: the composition of these CIs can be more effective than 2-MBT itself, which is little soluble in neutral media. The conclusion about mutual strengthening of copper protection by these CIs was confirmed by corrosion tests.

1. Yu.I. Kuznetsov and L.P. Kazansky, Physicochemical aspects of metal protection by azoles, Russ. Chem. Rev., 2008, 77, no. 3, 219–232. doi: 10.1070/RC2008v077n03ABEH003753

2. N.K. Allam, A.A. Nazeer and E.A. Ashour, A review of the effects of benzotriazole on the corrosion of copper and copper alloys in clean and polluted environments, J. Appl. Electrochem., 2009, 39, 961–969. doi: 10.1007/s10800-009-9779-4

3. M. Finšgar and I. Milošev, Inhibition of copper corrosion by 1,2,3-benzotriazole: A review, Corros. Sci., 2010, 52, 2737–2749. doi: 10.1016/j.corsci.2010.05.002

4. M. Petrović Mihajlović and M.M. Antonijević, Copper Corrosion Inhibitors. Period 2008–2014. A Review, Int. J. Electrochem. Sci., 2015, 10, 1027–1053. doi: 10.1016/S1452-3981(23)05053-8

5. Yu.I. Kuznetsov, Organic corrosion inhibitors: Where are we now? A review. Part II. Passivation and the role of chemical structure of carboxylates, Int. J. Corros. Scale Inhib., 2016, 5, no. 4, 282–318. doi: 10.17675/2305-6894-2016-5-4-1

6. O.A. Goncharova, A.Yu. Luchkin, N.N. Andreev, Yu.I. Kuznetsov, N.P. Andreeva and S.S. Vesely, Protection of copper by treatment with hot vaporous of octadecylamine, 1,2,3-benzotriazole and their mixture, Mater. Corros., 2018, 70, no. 1, 161–168. doi: 10.1002/maco.201810366

7. Yu.I. Kuznetsov, Triazoles as a class of multifunctional corrosion inhibitors. A review. Part I. 1,2,3-Benzotriazole and its derivatives. Copper, zinc and their alloys, Int. J. Corros. Scale Inhib., 2018, 3, 271–307. doi: 10.17675/2305-6894-2018-7-3-1

8. E. Rocca, G. Bertrand, C. Rapin and J.C. Labrune, Inhibition of copper aqueous corrosion by non-toxic linear sodium heptanoate: mechanism and ECAFM study, J. Electroanal. Chem., 2001, 503, no. 1–2, 133–140. doi: 10.1016/S0022-0728(01)00384-9

9. P. Wang, R. Qiua, D. Zhanga, Z. Lina and B. Hou, Fabricated super-hydrophobic film with potentiostatic electrolysis method on copper for corrosion protection. Electrochim. Acta, 2010, 56, 517–522. doi: 10.1016/j.electacta.2010.09.017

10. Ю.И. Кузнецов, И.А. Кузнецов и Н.П. Андреева, Формирование адсорбционных слоев на меди из водных растворов лаурата натрия и их защитное действие во влажной атмосфере, Коррозия: материалы, защита, 2017, 4, 26–32.

11. M.O. Agafonkina, Yu.I. Kuznetsov and N.P. Andreeva, Inhibitor Properties of Carboxylates and Their Adsorption on Copper from Aqueous Solutions, Russ. J. Phys. Chem., 2015, 89, no. 6, 1070–1076. doi:10.1134/S0036024415060023

12. J.E.O. Mayne, The mechanism of the inhibition of the corrosion of iron in the pH range 5–13, In Proceed. of the 4th Europ. Symp. on Corros. Inhib. Ferrara (Italy), 1975, 1, 1–5.

13. A.D. Mercer, The properties of carboxilates as corrosion inhibitors for steel and other metals in neutral aqueous solutions, In Proceed. of the 5th Europ. Symp. on Corros. Inhib. Ferrara (Italy), 1980, 2, 563–581.

14. G.T. Hefter, N.A. North and S.H. Tan, Organic corrosion inhibitors in neutral solutions. Part 1. Inhibition of steel, copper and aluminum by straight chain carboxylates, Corrosion, 1997, 53, 657–667. doi: 10.5006/1.3290298

15. K. Aramaki and T. Shimura, Self-assembled monolayers of carboxylate ions on passivated iron for preventing passive film breakdown, Corros. Sci., 2004, 46, 313–328. doi: 10.1016/S0010-938X(03)00156-2

16. P. Taheri, J. Wielant, T. Hauffman, J.R. Flores, F. Hannour, J.H.W. Dewit, J.M.C. Mol and H. Terryn, A comparison of the interfacial bonding properties of carboxylic acid functional groups on zinc and iron substrates, Electrochim. Acta, 2011, 56, no. 4, 1904–1911. doi: 10.1016/j.electacta.2010.10.079

17. U. Rammelt, S. Köhler and G. Reinhard, Electrochemical characterization of the ability of dicarboxylic acid salts to the corrosion inhibition of mild steel in aqueous solutions, Corros. Sci., 2011, 53, 3515–3520. doi: 10.1016/j.corsci.2011.06.023

18. D. Lahem, M. Poelman, F. Atmani and M.G. Olivier, Synergistic improvement of inhibitive activity of dicarboxylates in preventing mild steel corrosion in neutral aqueous solutions, Corros. Eng. Sci. Technol., 2012, 47, 463–471. doi: 10.1179/1743278212Y.0000000030

19. Yu.I. Kuznetsov, Organic corrosion inhibitors: where are we now? A review. Part II. Passivation and the role of chemical structure of carboxylates, Int. J. Corros. Scale Inhib., 2016, 5, 282–318. doi 10.17675/2305-6894-2016-5-4-1

20. G. Chan-Rosado and M.A. Pech-Canul, Influence of native oxide film age on the passivation of carbon steel in neutral aqueous solutions with a dicarboxylic acid, Corros. Sci., 2019, 153, 19–31. doi: 10.1016/j.corsci.2019.03.033

21. А.М. Семилетов, Ю.И. Кузнецов и А.А. Колесникова, О защите от атмосферной коррозии алюминиевого сплава АД31 антикоррозионной присадкой КАП-25, Коррозия: материалы, защита, 2019, 12, 17–22.

22. R.A. Scherrer and S.M. Howard, Use of distribution coefficients in quantitative structure-activity relationships, J. Med. Chem., 1977, 20, no. 1, 53–58. doi: 10.1021/jm00211a010

23. Yu.I. Kuznetsov, I.A. Kuznetsov and N.P. Andreeva, Adsorption of sodium tridecanoate on copper from aqueous solutions and copper protection from atmospheric corrosion, Int. J. Corros. Scale Inhib., 2018, 7, no. 4, 648–656. doi: 10.17675/2305-6894-2018-7-4-11

24. А.А. Чиркунов, Д.О. Чугунов и Ю.И.Кузнецов, Влияние винилтриметоксисилана на эффективность пассивирующих пленок на модифицированной фосфонатами поверхности стали, Коррозия: материалы, защита, 2019, 9, 14–18.

25. L.P. Kazansky, I.A. Selyaninov and Yu.I. Kuznetsov, Adsorption of 2-mercaptobenzothiazole on copper surface from phosphate solutions, Appl. Surf. Sci., 2012, 258, 6807–6813. doi: 10.1016/j.apsusc.2012.03.097.