Experimental and Theoretical Evaluations: Green Synthesis of New Organic Compound bis ethanethioyl oxalamide as Corrosion Inhibitor for Copper in 3.5% NaCl

Abstract

A newly synthesized (carbamothiol) oxalamide derivative N1, N2-bis (2-(((2-((2 aminoethyl) amino) ethyl) amino) ethanethioyl) oxalamide (bis N), was investigated for its ability to suppress corrosion of copper in 3.5% NaCl. The chemical structure was demonstrated using FT-IR, 1H-NMR, and 13C-NMR. According to weight loss (WL), potentiodynamic polarization (PDF), and electrochemical impedance spectroscopy (EIS) techniques, the synthetic inhibitor exhibits higher corrosion inhibition efficiency. The corrosion rate decreases and the inhibition efficiency increases linearly with the concentration of inhibitor, reaching 93.3% at 0.01M. The adsorption of bis N obeys the Langmuir adsorption isotherm. The calculated adsorption isotherm parameter ΔGads is a negative value equals to-10.14 KJ/mol, suggesting that the bis N is adsorbed on the copper surface and achieves the spontaneous process. The efficiency of bis N for metal protection enhancement is assessed using density functional theory (DFT). Evaluation and discussion of quantum different descriptors are also included.