The effects of structural variation in some isoxazolidines on the corrosion inhibition of carbon steel in 0.5 M sulfuric acid

Abstract

Purpose

The aim is to demonstrate corrosion inhibition capabilities of several isoxazolidines, containing hydrophobic substituents and having varying degree of steric congestion around nitrogen.

Design/methodology/approach

A number of isoxazolidines were prepared. Corrosion inhibition efficiencies of these organic compounds were determined by gravimetric and electrochemical methods, using carbon steel as the substrate metal and 0.5 M H₂SO₄ at 40‐70°C as the corrosive environment. Concentration of inhibitor was varied between 5 and 400 ppm.

Findings

Increase in steric congestion around the nitrogen centre and hydrophobic chain lengths as well as increase in temperature (in the presence of the inhibitor in the higher concentration range 100‐400 ppm) were found to increase the corrosion inhibition efficiency of the isoxazolidines. Electrochemical measurements corroborated these results. Thermodynamic parameters (ΔG_ads⁰,ΔH_ads⁰,ΔS_ads⁰) for the adsorption process and kinetic parameters for the metal dissolution (or hydrogen evolution) reaction were determined.

Originality/value

This is the first time the corrosion inhibition characteristics of isoxazolidines, an important class of readily accessible compounds, have been evaluated in H₂SO₄ medium.

Citation

Al‐Ghamdi, R.F., El‐Shareef, A.M., Saeed, M.T. and Ali, S.A. (2008), "The effects of structural variation in some isoxazolidines on the corrosion inhibition of carbon steel in 0.5 M sulfuric acid", Anti-Corrosion Methods and Materials, Vol. 55 No. 5, pp. 270-277. https://doi.org/10.1108/00035590810903863