Evaluation of corrosion inhibition characteristics of an N-propionanilide derivative for mild steel in 1 M HCl: Gravimetrical and computational studies

Due to its low cost, mild steel is frequently employed as a construction material in many industries. Unfortunately, due to the limited corrosion resistance of mild steel, it should be protected with barrier layers to keep it from corrosion in acidic or basic environments. An N- propionanilide derivative, namely 3-keto-3-((indolin-2-oneylidene)hydrazinyl)-N-propion-anilide (KIHP), was studied as a corrosion inhibitor of mild steel in a hydrochloric acid solution at a temperature of 303 K using gravimetrical measurements and density functional theory (DFT) simulation. The findings demonstrate that KIHP performs well as a mild steel corrosion inhibitor in 1 M HCl, with a greater inhibition efficacy of 95.3 percent for gravimetrical analysis at 0.0005 M KIHP concentration. The gravimetrical measurements at various temperatures (303 K to 333 K) were also studied at 5 hours immersion time. It was found that he protection efficacy decreases as the temperature rises. Based on our findings, we believe that KIHP could efficiently inhibit the acidic damage on a mild surface through physical and chemical adsorption. We computed separately the Gibbs free energy parameter. Quantum chemical simulations at the B3LYP/6-31G* level of theory were also applied to compute some electronic properties of molecules in an effort to see if there was a relationship between the inhibitory action and the structure of KIHP molecule.

Automated summary

Due to its limited corrosion resistance, mild steel needs to be protected with corrosion inhibitors in acidic or basic environments. This study investigated the corrosion inhibition performance of KIHP on mild steel in hydrochloric acid solution, and found that KIHP showed high inhibition efficiency at a concentration of 0.0005 M, with 95.3% corrosion inhibition. The protection efficacy decreased with increasing temperature, and there was a possible relationship between the inhibitory action and the structure of KIHP molecule.