Elektrokimyasal İnceleme ve DFT Yaklaşımı: 2-izopropil-4-metil-1,3-tiyazol-5-karboksilik asidin Yumuşak Çeliğin Korozyonuna Karşı İnhibisyon Etkisi

Abstract

The demand of metals and alloys is increasing in parallel with the world population and industrialization. In order to meet need, difficulties such as limited resources and environmental concerns during metallurgical processes come to the fore. In order to contribute to the elimination of these problems, it is an important research topic to protect the material from negative effects such as corrosion by increasing its strength. Organic inhibitors applied in low concentrations to corrosive aqueous media are the most common methods used for this purpose. In this study, the inhibitory properties of 2-isopropyl-4-methyl-1,3-thiazole-5-carboxylic acid (2I4MTA5C) against mild steel corrosion in acidic medium were investigated by electrochemical and quantum theoretical methods. Electrochemical impedance spectroscopy measurements and polarization curves were obtained in the presence and absence of 5 mM 2I4MTA5C in 0.5 M HCl during 168 hours of immersion, and the adsorption isotherm is presented. Experimental results were compared with quantum theoretical parameters in order to establish a relationship between molecular structure and electrochemical behavior and to investigate it in depth. According to the results obtained for the 168 hour immersion time, the resistance values for MS were 9.8 in the absence of 5 mM 2I4MTA5C and 200 ohm.cm-2 in the presence. The calculated corrosion current density values were 2.65 and 0.13 mA.cm-2 for MS in HCl and 5 mM 2I4MTA5C + HCl solution, respectively. The theoretically calculated HOMO and LUMO values were -6.88 eV and -1.80 eV. According to the results obtained, we can say that 2I4MTA5C is a suitable inhibitor candidate with 95.1% protection against mild steel corrosion.