Adsorption behavior of tautomeric forms of 2-aminino-5-mercato-1,3,4 – thiadizole as corrosion inhibitor on copper surface

Abstract

Purpose The purpose of this study is to evaluate the effect of the four tautomeric forms of 2-amino-5-mercatpo-1,3,4-thiadizole (AMT) absorbed on copper surface by the polar or non-polar groups. Polar group of AMT is mostly electronegative with larger N and S atoms as central atoms. 5-amino-1,3,4-thiadiazole-2(3H)-thion (AMT-c) has the highest adsorption energy and is easy to react with copper. The interaction between AMT-c and copper conforms to chemisorption, which is to be further verified by the experiment on the weight loss measurement. Design/methodology/approach Adsorption behavior of AMT as corrosion inhibitor on copper surface in oil field was studied by weight loss measurement, and the corrosion inhibition mechanism was analyzed. Reactive sites and distributions of tautomeric forms of AMT as inhibitor on Cu(100) crystal plane were calculated by density functional theory. Findings All atoms of AMT are in the same plane, and AMT is an aromatic ring structure by large p-chain adsorbed on the metal surface by a plane configuration. AMT-c has the highest adsorption energy and also the most stable isomerized product. The determinate locations of AMT on the Cu(100) surface are the bridge and the hollow sites using molecular dynamics. Corrosion of copper can be effectively inhibited by AMT, which is a kind of excellent corrosion inhibitor, and this property is attributed to the polar groups and non-polar groups of AMT that play a role as absorption and shielding on copper surface, respectively. Inhibition efficiency is increased with the increase in the concentration of the inhibitor. The maximum efficiency of 92 per cent is obtained for 50 ppm AMT concentration at 373 K, which is attributed to the presence of extensively delocalized electrons of the phenyl rings, planarity and the presence of lone pair of electrons on N and S atoms, which favored a greater adsorption of inhibitors on copper surface. Originality/value Corrosion of copper can be effectively inhibited by AMT, which is a kind of excellent corrosion inhibitor, and this property is attributed to the polar groups and non-polar groups of AMT that play a role as absorption and shielding on copper surface, respectively. Adsorption of AMT as corrosion inhibitor on copper surface obeys Langmuir isotherm. The interaction between AMT and copper conforms to chemisorption, which is to be further verified by the experiment on the weight loss measurement.

Understanding the Inhibition Mechanism of a Supramolecular Complex as the Corrosion Inhibitor for Mild Steel in the Condensate Water

“…There are several kinds of adsorption isotherm presented to evaluate the adsorption phenomenon on the metal surface (e.g., Frumkin, Langmuir, Temkin, and Freundlich isotherms, etc.). Based on the general method mentioned in the literature [38], the degree of surface coverage (θ, %) for the inhibitor could be evaluated from corrosion inhibition efficiencies. Thus, the corrosion inhibition efficiencies in Table 4 derived from gravimetric measurements (Table 2) were investigated graphically for fitting the aforementioned adsorption isotherms.…”

Corrosion Characteristics of Rolling Oil on the Rolled Copper Foil

“…In recent years, compounds containing B elements have gradually been of concern for the sake of environmental protection [14,15]. Corrosion inhibitors can be employed to reduce the corrosion of copper foil caused by the rolling oil [16,17]. Organic heterocyclic compounds containing heteroatoms such as N, O and S have been used as corrosion inhibitors to hinder the corrosion on copper [16][17][18][19].…”

“…Corrosion inhibitors can be employed to reduce the corrosion of copper foil caused by the rolling oil [16,17]. Organic heterocyclic compounds containing heteroatoms such as N, O and S have been used as corrosion inhibitors to hinder the corrosion on copper [16][17][18][19]. However, there is little research on what the main components are causing the corrosion of rolled copper foil and the corrosion mechanism of rolling oil on the rolled copper foil.…”