The potential of petai peel as a zinc corrosion inhibitor in sodium chloride solution

Abstract

The use of corrosion inhibitors is one of the methods for metal protection in acidic media and salt media. At present, the organic corrosion inhibitor is widely used in industry, because organic inhibitors are more environmentally friendly than inorganic inhibitors. One of the organic corrosion inhibitors is the Petai peel (Parkia speciosa). This study aims to apply the Petai peel as a zinc corrosion inhibitor in sodium chloride (NaCl) solution. This research applies Petai peel as an inhibitor in 3 forms, namely in the form of powder, extract, and tannin. Petai peel is used as a corrosion inhibitor because it contains tannins. The influential variables in this study include the inhibitors form, inhibitors concentration, and duration of immersion. The concentrations of inhibitors used are 2%, 4%, and 6% (w/v), respectively, and the immersion time in 3% NaCl solution varied up to 12 days. The measured parameters are corrosion rate and inhibition efficiency. The results showed that the three forms of inhibitors with a concentration of 2% are able to reduce the rate of corrosion of zinc in the NaCl solution, but the corrosion rate would decrease with increasing concentration of the inhibitor. During 12 days immersion, the lowest corrosion rate of zinc is 1.46 mpy, and the best inhibition efficiency is achieved at 90% on the third day.