Efektivitas Ekstrak Bunga Telang (Clitoria ternatea L.) sebagai Inhibitor Korosi Besi dan Seng dalam Medium Asam Klorida (HCl) dan Natrium Klorida (NaCl)

Abstract

The utilization of corrosion inhibitors as inhibitors of corrosion events is the best alternative in providing resistance to metals in corrosive media. Corrosion inhibitors can be sourced from organic and inorganic compounds. The use of inorganic inhibitors is prone to environment hazard, high toxicity, high price, and health hazard. Therefore, organic inhibitors are preferred as sustainable resource. In this study, telang flower (Clitoria ternatea L.) extract was selected as an iron and zinc corrosion inhibitor. The purpose of this study was to analyze the corrosion rate and corrosion inhibition efficiency of iron and zinc using corrosion inhibitor from telang flower extract in HCl and NaCl medium. Inhibitors extracts were varied with concentrations of 2%, 4%, 6% and 8% at immersion times 2, 4, 6, and 8 days in 50 mL medium of 3% HCl and 3% NaCl. The corrosion rate of metal plate was determined by weight reduction method. Based on the results, the highest extract yield was obtained at a powder:solvent ratio (1:10 w/v) of 39.5%. The results of FTIR analysis powder and extract telang flower contain flavonoids, terpenoids, steroids, and alkaloids. HPLC analysis total flavonoids from telang extract 20.474 ppm quercetin. The lowest corrosion rate of iron plate in 8-day immersion without inhibitor in 3% HCl and 3% NaCl was 273.169 and 13.858 (mpy), respectively, while the corrosion rate of zinc plate was 128.880 and 8.251 (mpy). After the addition telang flower extract inhibitor with 8% concentration, the lowest corrosion rate in HCl and NaCl medium on iron was 11.702 and 1.539 (mpy), respectively, while on zinc 7.859 and 0.786 (mpy). The highest inhibition efficiency was obtained with 8% inhibitor concentration in HCl and NaCl medium, on iron 95.72% and 88.88%, respectively, while zinc was 93.90% and 90.47%. The effectiveness of telang flower extract as corrosion inhibitor for iron and zinc resulted in the lowest corrosion rate and highest efficiency when 8% inhibitor was used and immersed for 8 days.