Adsorption Behavior of Glucosamine-Based, Pyrimidine-Fused Heterocycles as Green Corrosion Inhibitors for Mild Steel: Experimental and Theoretical Studies

Abstract

Effects of electron donating (−CH 3 and −OH) and electron withdrawing (−NO 2 ) substituents on the corrosion inhibition efficiency of four glucosamine-based, substituted, pyrimidine-fused heterocycles (CARBs) on mild steel corrosion in 1 M HCl have been investigated using gravimetric, electrochemical, surface morphology (SEM, AFM, and EDX), and computational techniques. Gravimetric studies showed that protection performances of the compounds increase with increase in concentration. Both electron withdrawing (−NO 2 ) and electron donating (−CH 3 and −OH) groups were found to enhance the inhibition efficiency, but the effect is more pronounced with electron-donating substituents. The compounds were found to be cathodic-type inhibitors as inferred from the results of potentiodynamic polarization studies. EIS studies suggested that the studied compounds inhibit metallic corrosion by adsorbing on metallic surface. The adsorption of the inhibitor molecules on steel surface was further supported by SEM, AFM, and EDX analyses. Adsorption of CARBs on a mild steel surface obeyed the Langmuir adsorption isotherm. Theoretical studies using quantum chemical calculations and molecular dynamics simulations provided additional insights into the roles of the −OH, −CH 3 , and −NO 2 substituents on the corrosion inhibition performances of the studied inhibitors.

Corrosion inhibition of mild steel in 1M HCl by D-glucose derivatives of dihydropyrido [2,3-d:6,5-d′] dipyrimidine-2, 4, 6, 8(1H,3H, 5H,7H)-tetraone

“…In continuation of our works on corrosion inhibition property of carbohydrate based corrosion inhibitors8, the present study considers the synthesis and investigation of corrosion inhibition effect of three novel D-glucose derivatives of dihydropyrido [2,3-d:6,5-d′] dipyrimidine-2, 4, 6, 8(1H,3H, 5H,7H)-tetraone namely, 5-((1S,2R,3R,4R)-1,2,3,4,5-pentahydroxypentyl)-10-phenyl-9,10-dihydropyrido[2,3-d:6,5-d′]dipyrimidine-2,4,6,8 (1H,3H, 5H,7H)- tetraone (GPH-1), 10- (4-hydroxy phenyl)- 5-((1S, 2R, 3R, 4R) -1,2,3,4,5-pentahydroxypentyl)-9,10-dihydropyrido [2,3-d:6,5-d′] dipyrimidine-2, 4, 6, 8(1H,3H, 5H,7H)-tetraone (GPH-2) and 10- (4-(methoxyphenyl)-5-((1S, 2R, 3R, 4R)-1, 2, 3, 4, 5-pentahydroxypentyl)-9,10-dihydropyrido[2,3-d:6,5-d′]dipyrimidine-2, 4, 6, 8(1H, 3H, 5H, 7H)-tetraone (GPH-3). The synthesized compounds were tested as prospective inhibitors of mild steel corrosion in hydrochloric acid using gravimetric, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), quantum chemical calculations and Monte Carlo simulations techniques.…”

Green Corrosion Inhibitors, Past, Present, and Future

“…This is achieved by density functional theory (DFT). DFT is one of the most important methods used in theoretical chemistry for corrosion inhibition to accurately predict the inhibition efficiencies based on the calculations provided by mechanistic information about metal-inhibitor interactions and can be performed for inhibitor molecules even before their synthesis [100][101][102][103][104][105].…”

Pyrimidine derivatives as potential corrosion inhibitors for steel in acid medium – An overview

“…Polarization results indicated that majority of these compounds behave as mixed type inhibitors. However, there are some compounds which act as cathodic-type inhibitors [16,28] and anodic inhibitors [21]. The adsorption of many of these compounds on steel surface followed Langmuir adsorption isotherm, where as few of the compounds were found to obey the Dubinin-Radushkevich adsorption isotherm [33,34], Frumkin adsorption isotherm [7] and Temkin's adsorption isotherm [21].…”