Chasew (Anacardium Occidentale) Leaves Extract as Green Corrosion Inhibitor of API 5L X52 in Acidic Media

Chasew leaves extract has been investigated as green corrosion inhibitor to inhibit the corrosion process of API 5L X52 in acidic media. The inhibition effect of cashew leaves was analyzed using electrochemical measurement such as Tafel Polarization and Electrochemical Impedance Spectroscopy (EIS). FTIR, polyphenol content and phytochemical analysis were also employed to ensure the chemical compound of cashew leaves extract. Concentration of cashew leaves extract was varied for electrochemical measurement i.e. 0, 100, 200, 300, 400 and 500 ppm. Furthermore, immersion time variation (0, 30 and 60 min) was used prior to electrochemical measurement. The electrochemical measurement results indicate that cashew leaves extract work effectively as green corrosion inhibitor of API 5L X52 in acidic media. The performance of this green corrosion inhibitor was optimum at concentration of 500 ppm and 60 min of immersion time. Cashew leaves extract was mixed-type inhibitor because the corrosion potential value shifted less than 85 mV. The Increasing of surface resistance value and the decreasing in the capacitance of double layer due to the adsorption process of cashew leaves extract molecules on the API 5L X52 steel surface.