Poly(sodium acrylate) and Poly(acrylic acid sodium) as an eco-friendly corrosion inhibitor of mild steel in normal hydrochloric acid: experimental, spectroscopic and theoretical approach

The anticorrosive performance of two acrylic polymers (PANa) and (PAA) on smild steel in the 0.1 M hydrochloric acid medium was investigated using numerous techniques, such as weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), Scanning electron spectroscopy (SEM), Energy-dispersive X-ray Analysis (EDAX), and DFT simulation. The obtained results through all tested methods are in good agreement. The polarization curves revealed that PANa and PAA belonged to mixed-type inhibitors. The influence of temperature on the corrosion of mild steel in 1.0 M HCl was also studied. The adsorption of PANa and PAA on mild steel surface in the studied medium follows the Langmuir isotherm. Scanning electron spectroscopy and Energy-dispersive X-ray analyses were carried out in order to study the mechanism which controls the corrosion inhibition of mild steel. Theoretical calculations realized using density functional theory (DFT), molecular dynamic (MD), and Monte Carlo (MC) simulations explored the most reactive sites of the investigated polymers.