Evaluation of 2-Dimethylaminopropionamidoantipyrine as a Corrosion Inhibitor for Mild Steel in HCl Solution: A Combined Experimental and Theoretical Study

Acombined experimental and theoretical study investigated the corrosion inhibition potential of 2-dimethylaminopropionamidoanti-pyrine (DMAPAAP) on mild steel in 1 M hydrochloric acid (HCl) solution. The weight loss method was used to determine the corrosion rate of mild steel in HCl solution both in the absence and presence of different concentrations of DMAPAAP. The effect of exposure time and temperature on the corrosion inhibition efficiency of DMAPAAP was also investigated. The results showed that DMAPAAP exhibited good inhibitory properties against the corrosion of mild steel in an HCl solution. The corrosion rate of mild steel increased with increasing inhibitor concentration, exposure time, and temperature. The highest inhibition efficiency of 91.9 % was achieved at 5 mM concentration of DMAPAAP after 5 hours of exposure time at 333 K. Density functional theory (DFT) calculations were carried out to support the experimental results and understand the inhibition process's mechanism. The adsorption of DMAPAAP on the mild steel surface was found to be both chemisorption and physisorption and followed the Langmuir adsorption isotherm. The inhibition efficiency increased with increasing electron-donating groups in the molecule, which was attributed to forming a protective film on the metal surface. Overall, the combined experimental and theoretical study provides a deeper understanding of the corrosion inhibition mechanism of DMAPAAP on mild steel in HCl solution and demonstrates its potential as an effective corrosion inhibitor for mild steel in industrial applications.</em>