NARROW-LEAVED PEPPERWORT (LEPIDIUM RUDERALE L.) FROM WESTERN KAZAKHSTAN - A NEW “GREEN” CORROSION INHIBITOR FOR CARBON STEEL

Tomiris Seilova

doi:10.37238/1680-0761.2023.90(2).46

Tomiris Seilova ЗКУ им. Утемисова

DOI: https://doi.org/10.37238/1680-0761.2023.90(2).46

Keywords: Keywords: Lepidium ruderale L.; plant extracts; inhibition efficiency; “green” inhibitors; metal protection.

Abstract

Annotation. In present work, the inhibitor properties of Lepidium ruderale L. aqueous extract (LRAE) was investigated by weight loss measurements and electrochemical techniques on the corrosion of carbon steel in typical acidic and saline media. It was established that the inhibitor efficiency of the LRAE reaches up to 91.05, 92.03, 93.84% in 1.0 mol/L hydrochloric, sulfuric, and phosphoric acids solutions respectively. Inhibition was found to increase with increasing in concentration of LRAE. In all tested media, the adsorption of the inhibitor molecules on metal surface was in accordance with Langmuir model and the high efficiency was achieved due to the spontaneous physisorption (ΔG⁰_abs ˃ -20 kJ/mol). Polarization curves revealed that LRAE act as a mixed type inhibitor and the inhibition efficiency of up to 95.34% can be obtained. Electrochemical data are in great agreement with gravimetrical experiment.