Inhibition of Brass (80/20) by 5-Mercaptopentyl-3-Amino-1,2,4-Triazole in Neutral Solutions

• Main Authors: Ivan А. Arkhipushkin, Khidmet S. Shikhaliev, Andrei Y. Potapov, Lyudmila V. Sapronova, Leonid P. Kazansky
• Format: Article
• Language: English
• Published: MDPI AG 2017-11-01
• Series: Metals
• Subjects: brass; neutral solution; corrosion inhibition; electrochemistry; XPS; mercaptopentylaminotriazole
• Online Access: https://www.mdpi.com/2075-4701/7/11/488
• ISSN: 2075-4701

The effect of the adsorption of 5-mercaptopentyl-3-amino-1,2,4-triazole (MPATA) on the corrosive behavior of brass (Cu80/Zn20) in neutral (pH 7.4) borate buffer solutions with and without 0.01 M NaCl was studied. Electrochemical methods show significant decrease of the anodic and cathodic currents on the polarization curves in the presence of MPATA. X-ray photoelectron spectroscopy (XPS) reveals MPATA adsorption on the brass surface from an inhibitor solution. After 17 h of exposure, a mixed complex [CuxZnyMPATAz] with a thickness of about 3–3.5 nm is formed on the surface. This nanolayer has sufficient protective ability to withstand corrosion tests in a salt fog chamber: after 5 days of testing, the samples remain glossy and less than 1% of the surface has been damaged. After corrosion tests in a salt fog chamber, the surface of unprotected samples is enriched with zinc, while at the surface of inhibitor-treated samples, the copper and zinc are present in practically equal contents.