Synthesis And Corrosion Inhibition Studies Of Benzoylthiourea Derivatives On Mild Steel In 1.0 M HCI
Eight derivatives of thiourea namely: 1-cyclohexyl-3-(4-fluorophenyl)thiourea (Ti), 1-(4-fluoro-benzoyl)-3-(4-fluorophenyl)thiourea (T2), 1-(4-fluoro-benzoyl)-3-(4- nitrophenyl)thiourea (T3), 1-(4-chloro-benzoyl)-3-(4-nitrophenyl)thiourea (T4), 1-(4- bromophenyl)-3-(4-chloro-benzoyl)thiourea (T5)...
Saved in:
| Main Author: | |
|---|---|
| Format: | Thesis |
| Language: | English |
| Subjects: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Eight derivatives of thiourea namely: 1-cyclohexyl-3-(4-fluorophenyl)thiourea (Ti),
1-(4-fluoro-benzoyl)-3-(4-fluorophenyl)thiourea (T2), 1-(4-fluoro-benzoyl)-3-(4-
nitrophenyl)thiourea (T3), 1-(4-chloro-benzoyl)-3-(4-nitrophenyl)thiourea (T4), 1-(4-
bromophenyl)-3-(4-chloro-benzoyl)thiourea (T5), 1-(4-chloro-benzoyl)-3-(4-fluorophenyl)
thiourea (T6), 1-(4-chloro-benzoyl)-3-(3-chloro-2-fluoro-phenyl)thiourea
(T7), and 1-(4-chloro-benzoyl)-3-(6-chloro-2-fluoro-3-methoxy-phenyl)thiourea (T8),
were successfully synthesized and characterized via micro elemental analyzer, FTIR,
1H and 13C NMR spectroscopy methods. From the FTIR spectral data, the compounds
are common to have the vibration frequency of stretching of v(N-H) around 3500-
3100 cmi1, v(C=O) around 1660-1720 cm-1, v(C=S) around 680-1440 cm-1 and v(C-N)
in the range of 1350-1000 cm-1. Three of the eight compounds which are T6, T7 and
T8 were selected for further study on their anticorrosion activity. The inhibition
property of the resulted compounds on the corrosion of mild steel in 1M hydrochloric
acid has been investigated at room temperature using weight loss, potentiodynamic
polarization measurements and electrochemical impedance spectroscopy (EIS). It was
found that, all the synthesized thiourea derivatives are capable to inhibit the corrosion
of mild steel. It was found that the inhibition efficiency increases with inhibitor
concentration and maximum efficiency was obtained at concentration 0.0004 M.
Among the studied inhibitors, T8 shows the best inhibition efficiency of greater than
90 %. The impedance spectra indicate that the inhibition process was attributed to the
formation of an adsorbed film that protects the metal surface against corrosive
medium. The potentiodynamic study reveals that the compounds studied acts
essentially as mixed type inhibitor which inhibits both the cathodic and anodic parts of
the corrosion reaction.
Keywords: thiourea, weight loss, polarization, corrosion inhibition, mild steel. |
|---|