The Modeling System of Isotherm Adsorption in Mechanism of Myrmecodia Pendans Extracts as the Corrosion Inhibitor in 3, 5% NaCl Solution

In this research, the weight loss experiment is conducted by using the material of API 5L Grade B in 3.5 % NaCl solution. Sarang Semut extract (Myrmecodia pendans) is used as the corrosion inhibitor. The immersion time period of weight loss experiment is 10, 20, and 30 days. The concentration of Sarang Semut extract which is used ranges to 100-500 mg/L. This research aims to determine the appropriate method of isotherms adsorption on each system. This is related to the surface protective layer which is formed on the surface of the Sarang Semut extract adsorption. The result of this experiment shows that with the time period of 10 days immersion, it follows the equation of the mixture adsorption type. Meanwhile, with the time period of 20 and 30 days, it follows the equation of Freundlich with the physical adsorption type.