Corrosion Inhibition Efficacy of Hybrid Organic Extracts from Prosopisafricana and Citrulluslanatus on Mild Steel in Acidic Medium

Résumé

Each of Prosopis Africana pod extract (PAPE) and Citrulluslanatus (WMPE) performed quite well as green inhibitors in the electrochemical corrosion in acidic solution at ambient temperature in previous research. However, the hybridization of these compounds was varied with the concentration ratio in this study to optimize the efficiency of the green inhibitor in a hydrochloric acid medium using mild steel. The extraction process of the inhibitor samples was carried out with the Soxhlet apparatus using n-hexane as the solvent. Furthermore, the potential inhibition efficiency was monitored using various corrosion measurement techniques at room temperature. The inhibitive response of the extracts could be attributed  to the adsorption of the extracts’ components on mild steel surface by physisorption mechanism according to the Langmuir adsorption isotherm model. The results revealed that inhibition efficiency (IE%) depends on the concentration of the extracts. The peak IE% values were obtained with a hybrid ratio of 3:1 (PAPE: WMPE) for gravimetric technique. The Tafel polarization and gasometrical measurement technique is 96.7%, 98.5% and 83.1% respectively at the concentration of 1.0 g/L, which are above the peak IE% for PAPE (93.7%, 80.96% and 77.8%) and WMPE (92.7%, 80.5% and 75.6%).