Pembuatan Biosurfaktan dari Alga Coklat Sargassum sp sebagai Corrosion Inhibitor

Abstract

Surfactant is an active surface agent, which functions to reduce surface tension, surface tension and can be used as an emulsifier. In general, surfactants are made from raw material based petrochemical that cannot be renewable. So from this research we uses brown algae as a renewable resource. Other advantages of brown algae such as biosurfactant including cleaner product, also containing fluorotanine, a phenolic compound that contains an antioxidant to reduce oxidation due to corrosion. Therefore, brown algae surfactants in this research will be tried for anti-corrosion through oxidation resistance on metal surfaces. The main process is the extraction of brown algae at a temperature of 80˚C which produces alkyl alginate, and then esterification using isopropyl alcohol and oleic acid with ratio (1: 1); (1: 2); (2: 1), producing biosurfactant isopropyl oleyl alginate. Corrosion tests were carried out by immersing galvanic metal in sea water, faucet water, and pond waters, then compare it with galvanic metals that have been coated using biosurfactants. The method to determine the corrosion rate on the galvanic surface is by weighing the original galvanic without biosurfactants with weight galvanic after coated with biosurfactants. The results of the analysis showed biosurfactants with ratio IPA: Oleic Acid (1: 2) can reduce the corrosion rate best by 78.33% compared to using IPA: Oleic Acid (1: 1) which is 58.64% and using IPA: Oleic Acid (2: 1)  62.25%. The corrosion rate of galvanized metal soaked in sea water, faucet water, and pond water without coated with biosurfactant was 0.0341 g / day, 0.0044 g / day, and 0.0012 g / day. While the corrosion rate of galvanized metal that coated biosurfactant by ratio IPA: Oleic Acid (1: 2) is 0.0077 g / day, 0.0015 g / day, 0.0001 g / day.