Natural products of gum arabic and frankinences as green inhibitors for mild steel corrosion in acidic medium

Abstract

In terms of environmental impacts and cost considerations, plants source were used as a vital alternative approach to organic inhibitors in combating the risk of corrosion. In this work, the properties of corrosion inhibition in gum arabic and frankinences and their components were experimentally examined on mild steel in HCl solution using weight loss methods. and potentiodynamic polarizationte technique. Characterization physical technique, namely electron microscopy scanning (SEM) was employed. Two natural product species of same family viz., gum arabic and frankinences, were investigated in terms of their corrosion inhibition efficiencies for mildd steel in 1 M HCl. Inhibition effect of different concentrations of gum arabic and frankinences viz., 2.5, 5, 7.5 and 10 g/L were tested using weight loss method and electrochemical potentiodynamic polarization measurements. Weight loss measurements were conducted for 4 h at 25, 60 and 85°C. The electrochemical potentiodynamic polarization measurements were carried out at 25°C. Overall, the results showed that both the inhibitors inhibited the corrosion of mild steel in acidic media via adsorption process on mild steel. The inhibition efficiencies increased with the increase in concentrations of the extracts and varied at different temperatures and immersion time. The obtained inhibition efficiencies of products were ranging from 46.84 to 81.76% for gum arabic and was between 53.15 and 84.51% in frankincense. The obtained inhibition efficiencies of products from polarization measurements were from 39.5 to 81% for gum arabic and 40.81 to 28.28% for frankincense respectively. Thus, these results showed that the higher the concentration (7.5 g/L and 10 g/L) of the inhibitor the higher the inhibition efficiency. The SEM image clearly showed a smooth and rough surface due to the presence of inhibition on the surface of the mild steel by the natural products. Therefore, potentiodynamic polarization studies were able to shows the inhibition in the presence of both gum arabic and frankincense.