Some azodyes as corrosion inhibitors for iron in HCl solution

¹ Chemistry Department, Faculty of Science, El-Mansoura University, El-Mansoura Egypt.
² Chemistry Department, Faculty of Science, Aleppo University, Aleppo Syria.

Abstract

The inhibitor effect of the quinazol-4-one derivatives on the corrosion of iron in hydrochloric acid solution was investigated. Polarization curves indicated that these compounds act as mixed type inhibitors, but the cathode is more preferentially polarized. The effect of structural changes in these compounds on their inhibition efficiency has been studied. The inhibitors appear to function through general adsorption following the Langmuir adsorption isotherm. Results indicate that the rate of corrosion of iron increases with increasing temperature over the range 27-50°C both in absence and in the presence of inhibitors. Some thermodynamic functions were also computed and are discussed.

Résumé

L'effet inhibiteur des dérivés de quinazol-4-one sur la corrosion du fer dans les solutions d’acide chlorhydrique a été étudié. Les courbes de polarisation indiquent que ces composés agissent comme des inhibiteurs de type mixte, mais la cathode est préférentiellement polarisée. L effet des changements de structure sur l'efficacité de l'inhibition a été étudiée. La vitesse de corrosion augmente avec la température dans la zone de 27 à 50°C, en absence et en présence d’inhibiteur.