Feasibility of Malus domestica (Apple) Pomace as an Organic Corrosion Inhibitor for Carbon Steel in Hydrochloric Acid

Abstract

Carbon steel is one of the most widely used metals in construction and manufacturing industries. Corrosion is one of the problems in the industrial environment because of its structural effects that include the loss of strength, fatigue, reduction of bond strength, limited ductility, and reduced shear capacity in metals. Pectin of Malus domestica (apple) pomace was extracted and liquefied. Three sets of carbon steel specimens with four pieces of steel were used in the experiment. The number of coating of Malus domestica (apple) pomace extract was different in each set of metal specimen. The same procedure for salt-spray test using hydrochloric acid (HCl) was conducted after the application of the extract. Weight loss measurement and rust formation were evaluated. The result showed that the steel carbon set with three coatings of Malus domestica (apple) pomace yielded the lowest amount of metal weight loss of 0.12g compared to the untreated carbon steel with 0.24g. Steel specimen with two and one extract coating yielded 0.21g and 0.18g weigh loss respectively. The rust formation is also more evident in the untreated carbon steel compared to the treated samples. Thus, Malus domestica (apple) pomace is an effective inhibitor of corrosion of carbon metal in an acidic solution.