Relationship between the molecular structure and the inhibition performance of triazole compounds using electrochemical methods

Corrosion inhibitors represent the most cost effective and flexible means of controlling internal corrosion associated with oil and gas production. Tests were carried out to demonstrate the structure/effect relationships which are effective in controlling the inhibition efficiency. To illustrate this approach, the substituent field effect at the paraposition of 1(Benzyl)1-H-4,5-Dibenzoyl-1,2,3-Triazole (BDBT) on corrosion inhibition has been investigated. Mild steel rotating cylinder electrode in acid media was used in conjunction with Tafel polarization technique, AC impedance measurements and continuous linear polarization resistance method. The nitro group was found to cause a considerable decrease in the corrosion inhibition of the parent compound BDBT. Owing to the induction effects of Br on the aromatic ring the bromo derivative has better inhibition protection than the methyl derivative. The corrosion rate profiles obtained from on-line polarization technique showed that the inhibition capacity of the studied substituents at the para-position increases as follows: NO₂ < CH₃ < Br < H.