Penghambatan Korosi Tembaga Menggunakan Ekstrak Tanin dari Gambir Asalan, Biji Pinang dan Kulit Manggis

Abstract

Copper is a metal widely used in industry because of its ability to conduct electricity and good mechanical ability. Although it has many advantages, copper faces problem relating with corrosion. The impact of corrosion can cause equipment damage, explosion, fire and death. Corrosion can not be avoided, but its rate can be decreased. In this research was made experimental corrosion inhibitor from material derived from raw gambier (Uncaria gambir Roxb.), areca nut (Areca catechu) and mangosteen peel (Garcinia mangostana). Those three materials are natural resources that owned by Indonesia. The general objective of this research was to produce the best solution on copper corrosion inhibitors that are environmentally friendly, while the specific objective of this study were to determine the effect of the source of tannins on the rate of corrosion on copper in 1 M HCl solution and to determine concentration of inhibitor that is effective in inhibiting corrosion on copper in solution of 1M HCl. Extract tannins from raw gambier, areca nut and mangosteen peel have the ability to inhibit corrosion on copper when soaked in a solution of HCl 1 M. The ability of the best inhibitors obtained from raw gambier-based solution with the lowest corrosion rate is 37.06 mpy, followed by areca nut 45.34 mpy and mangosteen peel 49.49 mpy while in the blank, the corrosion rate 190.46 mpy. Inhibitor efficiency of gambier amounted to 80.54%, betel nut 75.19% and mangosteen peel 74.01%. Activation energy value which needed by system with concentration of 0.00%, 0.50%, 0.75% and 1.00% are respectively 6285 J/mol, 26347 J/mol, 31551 J/mol and 28749 J/mol. Therefor, the addition of inhibitors as much as 0.75% at temperature of 303 K, 308 K, 313 K and 318 K was effective in inhibiting the corrosion rate. This is supported the copper appearance data which not change into greenich blue color while given by 0.75% tannin concentration.