Adsorption and corrosion inhibitive properties

of some tripodal pyrazolic compounds on mild steel

in hydrochloric acid systems


H. Bendaha1 A. Zarrouk1*, A. Aouniti1, B. Hammouti1, S. El Kadiri1, R. Salghi2, R. Touzani1,3

1Université Mohammed Premier, Faculté des Sciences,  LCAE-URAC 18,  Oujda-Morocco.

2 Equipe de Génie de l’Environnement et Biotechnologie, ENSA, Université Ibn Zohr, BP1136 Agadir, Morocco.  

3 Université Mohammed Premier, Faculté Pluridisciplinaire Nador-Morocco. 

* Corresponding author. E-mail:

Received: 30 January 2012; revised version accepted: 02 February 2012



     The corrosion and inhibitors adsorption processes in mild steel / two tripodal pyrazolic compounds namly3-[Bis-(3,5-dimethyl-pyrazol-1-ylmethyl)-amino]-propan-1-ol(Tpyr1) and 1-[Bis-(3 carbomethoxy-5-methyl-pyrazol-1-ylmethyl)-amino]-propan-2-ol (Tpyr2) / hydrochloric acid systems were studied at different temperatures (308-323 K) by means weight loss (WL) measurements. It has found that the studied compounds exhibit a very good performance as inhibitors for mild steel corrosion in 1.0 M HCl. Results show that the inhibition efficiency increases with decreasing temperature and increasing concentration of inhibitors. It has been determined that the adsorption for the studied inhibitors on mild steel complies with the Langmuir adsorption. The kinetic and thermodynamic parameters for mild steel corrosion and inhibitor adsorption were determined and discussed, respectively. On the bases of thermodynamic adsorption parameters, comprehensive adsorption (physisorption and chemisorption) for the studied inhibitors on mild steel surface has been suggested.


Keywords: Mild steel; Corrosion; Thermodynamic; tripodal pyrazolic compounds; Adsorption; HCl.



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