Study of Combination of Physalis angulata Leaf and Cassia angustifolia Leaf Extract with a 50:50 Ratio as Green Inhibitor for API 5L in 1M HCl Solution

Study of mixed-type Green Inhibitor for API 5L in HCl Solution

Abstract

The effect of combination of Physalis angulata leaf and Cassia angustifolia leaf extract as green inhibitor with a 50:50 ratio for API 5L steel was investigated. This experiment was carried in 1M HCl solution by using different concentrations as variables which is 10 ml, 30 ml, and 50 ml inhibitor extracts. Evaluation of this experiment was performed using potentiodynamic polarization and EIS. The antioxidant compound was investigated using FTIR and was found to be flavonoid. It was found that the capability of the inhibitor to inhibit the steel surface from the environment increases with increasing concentration, which 50 ml concentration is found to have the best efficiency of all concentrations. Combination of Physalis angulata leaf and Cassia angustifolia leaf extract is identified as mixed-type inhibitor with predominant cathodic effectiveness. The adsorption of this inhibitor on the steel surface was predominantly through physisorption and obeyed Langmuir adsorption isotherm.