Molecular Interaction of Lactams With Mild Steel in Hydrochloric Acid Environment

Abstract

The inhibition effect of some lactams (Pyrrolidin‐2‐one, δ‐valerolactam, and ε‐caprolactam) on the corrosion behaviour of mild steel in 1M Hydrochloric acid solution was studied by weight loss and electrochemical techniques. The results demonstrated that both δ‐valerolactam, and ε‐caprolactam significantly inhibit corrosion. Specifically, δ‐valerolactam achieved an inhibition efficiency of 85.2%, while ε‐caprolactam exhibited a higher inhibition efficiency of 91.5%. The thermodynamic parameters governing the adsorption process such as adsorption heat, adsorption entropy, and adsorption free energy were determined and discussed. The adsorption of lactam compounds on the mild steel surface in 1M HCl follows the Langmuir adsorption isotherm model.