Opuntia Ficus Indica Seed Oil:Characterization and Application in Corrosion Inhibition of Carbon Steel in Acid Medium

The aim of this work is to characterise seed oil of opuntia ficus indica and to develop a new formulation to inhibit carbon steel corrosion in acidic medium. “OTH”, is a new environmentally friendly corrosion inhibitor containing Opuntia ficus indica seed oil. Fatty acid composition was analysed by Gas-chromatography after transesterification to Fatty Methyl esters (FAMES). The Electrochemical Impedance Spectroscopy (EIS) and voltamperometry measurements were carried out for different concentrations and immersion times. Surface analyses were carried out by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). The results obtained show that the main fatty acids of prickly pear seed oil were C16:0, C18:0, C18:1, C18:2. The content of unsaturated fatty acids was high (83%). Electrochemical measurements show that OTH acts as a good mixed corrosion inhibitor. This inhibitor formulation forms a thick film that plays a barrier layer on the iron surface to minimize the contact area with corrosive solution and hinder metal oxidation.