INHIBITION OF COPPER CORROSION IN CHLORID E SOLUTION BY BENZO-HYDROXAMIC ACIDS

A comparative study was made on the inhibition effect of hydroxamic ac ids (substituted by chloro, methyl and nitro groups in the phenyl ring ) on copper corrosion in 0.5 mol dm(-3) NaCl solution in order to obta in information on the influence of substituents on the efficiency and to get deeper insight into processes at the metal/solution interface. For characterisation of inhibitors electrochemical (polarisation, impe dance spectroscopy) and EQCM methods were applied. The results showed that p-chloro substitution provided the best inhibitive effect. In a s olution which contains chloride ion a poorly soluble layer is formed w hich is responsible for the efficacy.