Inhibition by some Thiocompounds of the Corrosion of Copper in Monochloracetic Acid Solution

The inhibitory action of ethanolthiol, 2-mercaptoethanol and dodecyl mercaptan towards the corrosion of copper (99·8 %) in 0·1 M monochloracetic acid has been investigated. The inhibitive efficiency of these compounds may be arranged in the following order: dodecyl mercaptan > 2-mercaptoethanol > ethanolthiol. Polarisation measurements indicated that the compounds were principally cathodic corrosion inhibitors. I.R. spectra of the protective film formed on copper in solution inhibited with 2-mercaptoethanol, and of the pure chelate synthesised from 2-mercaptoethanol and copper ions in solution, were found to be identical.