Effect of some new diazole derivatives on the corrosion behaviour of steel in 1 M HCl

Abstract

ab s t r ac tThe inhibiting properties of four diazole derivatives namely 2,2'-ethylene-bis(benzimidazole) (EBBI), 2,2'-buthylene-bis(benzimidazole) (BBBI), 2,2'-hexamethylene-bis(benzimidazole) (HBBI) and 2,2'-octamethylene-bis(benzimidazole) (OBBI), against the corrosion of mild steel in solutions of hydrochloric acid has been studied by various corrosion monitoring techniques and reported here for the first time. Preliminary screening of the inhibition efficiency was carried out using weight loss measurements. At the inhibitor concentration range of 10 -5 -5×10 -4 M) in 1 M HCl, the inhibitor efficiency increases with concentration of the organic substrate. Potentiodynamic polarisation studies showed that these compounds suppressed both cathodic and anodic processes of mild steel corrosion in 1 M HCl by adsorption on the metal surface according to Langmuir adsorption isotherm. The values of free energies of adsorption (ΔG 0 ads ) suggest a mixed physisorptions and chemisorption of diazole molecules on the steel surface. The inhibition efficiency of these inhibitors increases in the order OBBI > HBBI > BBI > EBBI.

Evaluation of the inhibitory action of essential oil from Eucalyptus globulus leaves on the corrosion of mild carbon steel in 1M HCl medium

“…Among these means of protection, we find corrosion inhibitors. It should be noted that most of the inhibitors used in an acid environment are of the synthetic organic type [4][5][6][7][8][9]. However, the disadvantage of these types of inhibitors lies in their high toxicity as well as the harmful impacts they can have on the environment.…”

Anti‐corrosion properties of bis(benzimidazole) derivatives for N80 steel in H2S solution

“…Benzimidazole derivatives are regarded as an important group of heterocycles, which can be frequently found in life science and functional material science owing to their low toxicity, long‐term stability and strong coordination ability. Especially as corrosion inhibitors, benzimidazole derivatives can effectively restrain metal corrosion through adsorbing on metal surface, and this adsorption capacity depends mainly on physicochemical properties of the molecule, such as functional groups, steric effect, molecular structure, aromaticity, electron density at the donor atoms and p ‐orbital character of donating electrons . Bis(benzimidazole) derivatives are often advantageous over single‐component systems for a range of fundamental studies and applications because the more heteroatoms in compositions and spatial distributions provide additional chance for adsorption on metal surface .…”