TITLE:
Corrosion Inhibitory Studies of Novel Schiff Bases Derived from Hydralazine Hydrochloride on Mild Steel in Acidic Media
AUTHORS:
Romanus N. Njong, Bridget N. Ndosiri, Emmanuel N. Nfor, Offiong E. Offiong
KEYWORDS:
Mild Steel, Hydralazine Hydrochloride, Weight Loss, Corrosion Inhibition
JOURNAL NAME:
Open Journal of Physical Chemistry,
Vol.8 No.1,
February
26,
2018
ABSTRACT: The inhibition performance of 1-hydralazinophthalazine (HPZ) (1), and
synthesized1-(2-[(5-methylfuran-2-yl)methylene)] hydrazono) phthalazine (MFHPZ) (2),
1-(phthalazin-1(2H)-one) [(pyridin-2-yl) ethylidene] hydrazone (ACPHPZ) (3) and (2-acetylthiophene hydrazono) phthalazine (ACTHPZ) (4) has been
investigated for mild steel in 1 M HCl. Compound 4 shows maximum inhibition
efficiency of 93% at 5.0 × 10-3 M concentration. The
evaluation of thermodynamics and activation parameters indicated spontaneous
adsorption of the inhibitor molecules which takes place through chemisorption.
The adsorption of 3 and 2 follows Langmuir adsorption isotherm
and Temkin adsorption isotherm for 4 and 1. The inhibitor
efficiency was of the order 4 > 3 > 1 > 2. Impedance study for the representative inhibitor compounds 4 and 3 showed that decrease in charge transfer resistance is responsible for
effective protection of mild steel surface by the tested inhibitor.