Ekstraksi Daun Gambir Menggunakan Pelarut Metanol-Air Sebagai Inhibitor Korosi

Abstract

Corrosion is the most damaging effect on metal and need a way to handle it.Corrosion prevention process can be carried out, such as by coating the metalsurface, cathodic protection, corrosion inhibitor addition, and others. The use ofinhibitors is safe, readily available, biodegradable, low cost, and environmentallyfriendly is necessary, such as with gambier extract. This study aims to determine theeffectiveness of leaf extract gambier using methanol-water as a corrosion inhibitor.Soaking ferrous iron plate samples in seawater media (pH 3; 6; and 9) for corrosiontest performed with varying contact time 5; 10; 15; and 20 days. After the time is upnext ferrous iron plate samples are cleaned, dried, and weighed. Experiment wasrepeated by adding inhibitor leaf extract gambier extract gambier with varyingweight 1000; 3000; and 5000 ppm. Calculation is then performed and the rate ofcorrosion inhibition efficiency of leaf extract gambier with methanol-water solvent.On the immersion of iron without inhibitor, the result that the longer the contacttime, the weight of the iron is reduced. The addition of inhibitors of leaf extractgambier with methanol-water solvent into the corrosive media can reduce the rate ofcorrosion. The greater the concentration of inhibitor were added and the longer thecontact time the corrosion rate decreases. Conditions of acidic sea water will increasethe rate of corrosion of iron. The results of this research showed that the lowestcorrosion rate of iron is 0,000547 gr/cm2 day at concentration of inhibitor 5000 ppmand contact time of 20 days with the inhibition efficiency is 51,78%. At variation pHof seawater are obtained the lowest corrosion rate of iron at pH of seawater 9 is0,000503 gr/cm2 day.

Keywords: corrosion, extraction, gambier leaves, inhibitors, methanol-watersolvent