ISSN 3041-1815. Physicochemical Mechanics of Materials. 2026.
Volume 62, Issue 3
Mechanism of iron corrosion inhibition with morpholine based quaternary ammonium salts in methanesulfonic acid
Amirulloieva N. V. 
Ukrainian State University of Science and Technologies, SEI “Prydniprovska State Academy of Civil Engineering and Architecture”, Dnipro, Ukraine. (https://ror.org/052pe2w94)
University of Latvia, Riga, Latvia (https://ror.org/05g3mes96)
Sknar Yu. Ye.
Ukrainian State University of Science and Technologies, SEI “Ukrainian State University of Chemical Technology”, Dnipro, Ukraine. (https://ror.org/052pe2w94)
Amirulloiev R. S.
Ukrainian State University of Science and Technologies, SEI “Ukrainian State University of Chemical Technology”, Dnipro, Ukraine. (https://ror.org/052pe2w94)
Keywords
morpholine, inhibitor, corrosion, iron, adsorption, inhibiting effect, “blocking” model.
Cite as
Amirulloieva N. V., Sknar Yu. Ye., and Amirulloiev R. S. Mechanism of iron corrosion inhibition with morpholine based quaternary ammonium salts in methanesulfonic acid. Physicochemical Mechanics of Materials. 2026. 62(3), 39-47.
Abstract
Corrosion resistance of iron in the presence of morpholine‑based quaternary ammonium salts (QASM) in methanesulfonic acid, selected as the background electrolyte, was investigated. The adsorption and kinetic properties of QASM were studied using the coulostattic method. The adsorption equilibrium constants of QASM on iron in an acidic medium increase in the sequence C11H22BrNO < C10H18BrNO < C18H22ClNO < (C16H28NO7Cl)n. The obtained dependences of the corrosion current of iron on the electrode surface coverage by QASM indicate their significantly lower inhibiting effect than predicted by the “blocking” model, due to a substantial contribution of the energy retardation. The results confirm the prospects of using QASM as inhibitors of acid corrosion of steel and indicate the possibility of applying the most effective compounds (C18H22ClNO < (C16H28NO7Cl)n) under industrial conditions.