The 3,5-bis(n-tolyl)-4-amino-1,2,4-triazoles as corrosion inhibitors of mildsteel in acidic media: electrochemical and quantum chemical studies

摘要

The corrosion inhibition of mild steel by some new synthesized triazole organic-typerncompounds, the 3,5-di(n-tolyl)-4-amino-1,2,4-triazoles (n-DTAT: n = 2, 3, 4), wasrninvestigated in 1 M HCl and 0.5 M H2SO4 using weight loss measurements, electrochemicalrnimpedance spectroscopy and polarization curves. The ability of the n-DTAT to inhibit therncorrosion of mild steel is dependent on the position of the CH3 group on the tolyl substituent.rnThe inhibition efficiency of the tested compounds has been found to decrease as follows: 4-rnDTAT > 3-DTAT > 2-DTAT. Polarization curves studies showed that 4-DTAT is a mixedtyperninhibitor in 1 M HCl and cathodic–type in 0.5 M H2SO4. This inhibitor acts on therncathodic reaction without changing the mechanism of the hydrogen evolution reaction. Thern4-DTAT appears to function through the general adsorption mode following the Langmuirrnadsorption isotherm model in acidic media. The electronic properties of isomers of DTATrnobtained by using the Hartree Fock AB initio 3-21G quantum chemical approach, wererncorrelated with their experimental efficiencies.