Indonesia Conference Directory

Turmeric is one of the plants that contains antioxidant compounds called curcumin. Antioxidants in curcumin include flavonoids and tannins. Antioxidants can be used as corrosion inhibitors and paint additives. This study aims to utilize turmeric extract as an inhibitor and additive coating agent for aluminum metal in the seawater environment. Turmeric is extracted using a methanol or acetone solvent with a sample: solvent ratio of 1: 8. Phytochemical and DPPH (1,1-Diphenyl-2-Picrylhydrazyl) analyzes were performed. Testing of extracts as inhibitors and coating additives was carried out by varying the concentration and time of corroding. The results showed that the extract produced contained flavonoids and tannins through qualitative tests using 1% FeCl3 and 10% NaOH, each of which gave a blackish green and a blackish red color. Antioxidant activity was tested by the DPPH method in acetone and methanol, which respectively showed 4509 ppm and 2057 ppm. The testing of turmeric extract as a coating additive was immersed for five days and obtained the best level of 1% which produced the lowest corrosion rate of 0.0228 mmpy with a protection efficiency of 68.60%. Turmeric extract corrosion test as a coating additive was achieved within eight days with a corrosion rate of 0.0011 mmpy and a protection efficiency of 88.89%.