الفهرس 
Material and experimentsOnly 14 pages are availabe for public view
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Abstract
The environmental pollution from leaking oil lines due to corrosion
is one of the important problems in petroleum sector. Corrosion inhibitors
are used in acidic solutions to decrease the dissolution of the metallic
materials In this study, naturally occurring vanillin was chemically
modified into cationic surface active agents and non ionic surface active
agents containing hydrocarbon chains with different lengths.
Three new environmental friendly surfactants of cationic type were
synthesized using natural vanillin. Their chemical structures were
determined using elemental, IR, 1H NMR and 13C NMR spectroscopic
analyses. The surface activity of the synthesized surfactant solutions was
determined using surface and interfacial tension measurements at 25 ◦C.
The emulsification powers of these surfactants were measured against
light paraffin oil. The biodegradation ability of the surfactants reached the
maximum (75%) within 21 days. Corrosion inhibition characteristics of
the green surfactants were determined on carbon steel in 1 N HCl at 25 ◦C
using gravimetric and potentiodynamic techniques. The adsorption of
inhibitors on carbon steel in 1N HCl follows Langmuir adsorption
isotherm. Thermodynamic adsorption parameters (Kads, _Gads) of
studied inhibitors were calculated using the Langmuir adsorption
isotherm. The Tafel polarization results indicate that the inhibitors act as
mixed inhibitors. The inhibition efficiency increases with an increase in
the inhibitor dose, side chain length and surface activity of the inhibitors
The maximum inhibition efficiencies ranged between 95.09% and
98.53% at 400 ppm.
Four environmentally friendly corrosion inhibitors were derived
from vanillin and were evaluated gravimetrically
and electrochemically as corrosion inhibitors for carbon steel in 1 M HCl.
The inhibition efficiencies
of these inhibitors were depending on their concentration and the
chemical structures. The
adsorption of these inhibitors was found to obey Langmuir adsorption
model. Polarization measurements showed the mixed type behavior of
these inhibitors, which inhibits the cathodic and anodic parts of the
corrosion reaction in 1 M HCl.