Analyses of natural okra extracts as corrosion inhibitors on mild steel in acidic medium

Abstract

Plant extracts have been shown to effectively inhibit the corrosion of metals. Using the Box-Behnken, gravimetric, and electrochemical techniques, analyses were designed to investigate the anti-corrosion potential of okra in a 1M HCl medium. The inhibition performances derived from the various methods were in good agreement, demonstrating that physio-chemisorption was effective and adhered to the Langmuir isotherm. The efficiency of okra mucilage powder was 96% at a much lower concentration, compared to 91.2% and 88.4% for the unsieved extract and gelly-okra filtrate, respectively. FTIR results showed the presence of several functional groups that promoted adsorption, and TGA analysis revealed that the extract had high thermal stability. The FESEM analysis also revealed evidence of adsorption. It was determined that corrosion inhibition by okra mucilage extract was primarily influenced by temperature, followed by extract concentration, with immersion time having the least effect. From the model optimization goal, 200ppm, 60°C, and 24h for 89.98% IE gave a high desirability. The results showed the high capacity of okra as an efficient biodegradable corrosion inhibitor.