|
NISCAIR ONLINE PERIODICALS REPOSITORY (NOPR) >
NISCAIR PUBLICATIONS >
Research Journals >
Indian Journal of Chemical Technology (IJCT) >
IJCT Vol.18 [2011] >
IJCT Vol.18(3) [May 2011] >
| Title: | Inhibition efficiency of two bipyrazole derivatives on steel corrosion in hydrochloric acid media |
| Authors: | Tebbji, K
Aouniti, A
Attayibat, A
Hammouti, B
Oudda, H
Benkaddour, M
Radi, S
Nahle, A |
| Keywords: | Pyrazole
Steel
Hydrochloric acid
Corrosion inhibition
Adsorption |
| Issue Date: | May-2011 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | The inhibitor effect of two isomers namely
2-(1',5,5'-trimethyl-1H,1'H-3,3'-bipyrazol-1-yl)ethanol (1-TBE) and
2-(1',5,5'-trimethyl-1H,2'H-3,3'-bipyrazol-2-yl)ethanol (2-TBE) on the
corrosion of mild steel in 1.0
M hydrochloric acid has been investigated at 308 K using
weight loss measurements and electrochemical techniques (impedance spectroscopy
and polarisation curves). Inhibition efficiency is dependent upon the pyrazole
structure, with 1-TBE serving as a better inhibitor than 2-TBE and its
inhibition efficiency increases with the increase of concentration of inhibitor
to attain 93% in the presence of 10-3M. Polarisation curves indicate
that 1-TBE and 2-TBE act essentially as cathodic inhibitors. Efficiency (E) percent values obtained by various
methods are reasonably good in agreement. EIS measurements show an increase of
the transfer resistance with the inhibitor concentration. The temperature
effect on the corrosion behaviour of steel in 1.0 M HCl without and with
the inhibitor at 10-3M is studied in the temperature range 308-333
K, Some thermodynamic parameters such as adsorption heat ( H°), adsorption entropy (S°) and adsorption free energy (G°) have been calculated by employing thermodynamic equations. Kinetic
parameters such as apparent activation energy and pre-exponential factor have
also been calculated. Adsorption of 1-TBE on the mild steel surface in 1.0 M HCl follows the
Langmuir isotherm model. |
| Page(s): | 244-253 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-0991 (Online); 0971-457X (Print) |
| Source: | IJCT Vol.18(3) [May 2011]
|
|
