Utilization of Natural Tannin Extract for Copper Corrosion Inhibitor in Hydrochloric Acid Solution

Abstract

Inhibitor of copper corrosion in 1M hydrochloric acid (HCl) solution by utilizing natural tannin extracted from raw gambier (Uncaria gambier Roxb.), areca nut (Areca catechu) and mangosteen peel (Garcinia mangostana) was investigated. Tannin functional groups were detected by FTIR analysis, the effect of tannin source and tannin concentration in copper corrosion inhibition were investigated by weight loss method (gravimetric). The ability of the best inhibitors was derived from raw gambier-based solution with lowest corrosion rate of 37.06 mils per year (mpy), followed by areca nut 45.34 mpy and mangosteen peel 49.49 mpy. The best concentraction of inhibitor was 0.75% which gives highest activation energy value and good surface appearance of the copper plate.

Keywords: copper, corrosion rate, corrosion inhibitor, raw gambier, areca nut, mangosteen peel