Synthesis, inhibition effects and quantum chemical studies of a novel coumarin derivative on the corrosion of mild steel in a hydrochloric acid solution

Abstract

Background The acid corrosion inhibition process of mild steel in 1 M HCl by 4-[(2-amino-1, 3, 4-thiadiazol-5-yl)methoxy]coumarin (ATC), has been investigated using weight loss technique and scanning electron microscopy (SEM). ATC was synthesized, and its chemical structure was elucidated and confirmed using spectroscopic techniques (infrared and nuclear magnetic resonance spectroscopy).FindingsThe results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. The adsorption equilibrium constant (K) and standard free energy of adsorption (ΔGads) were calculated. Quantum chemical parameters such as highest occupied molecular orbital energy, lowest unoccupied molecular orbital energy (EHOMO and ELUMO, respectively) and dipole moment (μ) were calculated and discussed. The results showed that the corrosion inhibition efficiency increased with an increase in both the EHOMO and μ values but with a decrease in the ELUMO value.ConclusionsOur research show that the synthesized macromolecule represents an excellent inhibitor for materials in acidic solutions. The efficiency of this macromolecule had maximum inhibition efficiency up to 96 % at 0.5 mM and diminishes with a higher temperature degree, which is revealing of chemical adsorption. An inhibitor molecule were absorbed by metal surface and follow Langmuir isotherms low and establishes an efficient macromolecule inhibitor having excellent inhibitive properties due to entity of S (sulfur) atom, N (nitrogen) atom and O (oxygen) atom.

New Corrosion Inhibitor Derived from Coumarin

“…Structure modification of coumarin moiety exhibit inhibition of unit enzyme both in vitro and in vivo [16][17][18][19][20]. Corrosion inhibitors increase the impedance of mild steel toward corrosive solutions and inhibit or retard the corrosion through adsorbing the molecules of inhibitor on the surface of mild steel [21][22][23][24][25][26][27] in order to generate a barrier on the surface that block dynamic sites for mild steel [28][29][30]. Natural or synthesized organic corrosion inhibitors may have adsorbed on metal surface.…”

Experimental and Quantum Chemical Studies on the Corrosion Inhibition of Mild Steel By 2-((Thiophen-2-Ylmethylene) Amino)Benzenethio in 1M HCl

“…Mild steel coupons texture of C (0.21%), Si (0.38%), Mn (0.05%), P (0.09%), Al (0.01%), and Fe (99.21%) were utilized for weight loss investigations. The coupons were cleaned according to the standard procedure to be specific ASTM G1-03 (13)(14)(15)(16)(17)(18)(19)(20)(21)(22). In a typical methodology, coupons were suspended volume 200 mL of a corrosive solution (in duplicate) to try or not of 2-((thiophen-2-ylmethylene) amino) benzenethiol.…”

Inhibitive impacts extract ofCitrus aurantiumleaves of carbon steel in corrosive media

“…Anticorrosion coatings are generally employed to inhibit the average of corrosion and increase the longevity of the mild steel. A broad range of organic adsorption inhibitors presently applied in the corrosion domain is expensive (10)(11)(12)(13)(14)(15)(16). Inhibitor adsorption on mild steel is affected by the nature of the mild steel, type of electrolyte, and molecular structure of the inhibitor (17)(18)(19)(20)(21).…”