Studies of the anticorrosion property of a newly synthesized Green isoxazolidine for API 5L X60 steel in acid environment

Abstract

The potential of an environmentally friendly novel synthesized and characterized isoxazolidine derivative namely 5-(4-dodecyloxy-3-methoxybenzyl)-2-methylisoxazolidine (DMBMI) as anticorrosion agent for carbon steel in 1 mol/L HCl solution was investigated using gravimetric and electrochemical techniques. Kinetics parameters of the corrosion process and the thermodynamic data of adsorption of the organic molecule on the carbon steel surface was also assessed in order to characterize the performance of the studied compound as a corrosion inhibitor. The solubility, toxicity and the state of the molecule at the acidic pH (1 mol/L HCl) was predicted. It was found that the synthesized compound is green (environmentally friendly) with an optimum solubility of 23.8 mg/L. Also the molecule exists 100 percent in protonated form in 1 mol/L HCl (pH = 0). The molecule possesses anticorrosion property against steel corrosion in acid environment. Corrosion retardation efficacy is dependent on concentration and temperature. DMBMI exhibited concentration dependent corrosion inhibition ability influencing mainly anodic metal dissolution based on potentiodynamic polarization data. Addition of KI through the mechanism of competitive adsorption enhanced the inhibition efficiency considerably. The active sites for the interaction of DMBMI with steel surface was calculated using quantum chemical method while the adsorption energy between the inhibitor and steel surface was derived via Monte Carlo simulations. Results from theoretical studies and surface analysis are in conformity and reveal that the O and N heteroatoms in the synthesized molecule are the interaction centers. Keywords: Isoxazolidine compounds, Theoretical studies, Corrosion inhibitor, Acid corrosion, Steel