13A STUDY OF CORROSION INHIBITION EFFECT OF PYRIDINE BASED SCHIFF BASE
ON IRON METAL IN 0.5M HClNavin Maharia1, Sanjay Kumar2 and V. K. Swami3
Research Laboratory, Department of Chemistry, Govt. Lohia PG College, Churu, Raj., India
2Assistant Professor, S. N. K. P. Govt. College, Neemkathana, Sikar, Raj., India
3Principal, Govt. SBD College, Sardarshahar (Churu), Rajasthan, India
Email: sanjaysnkp@gmail.com

1How to cite this paper:Maharia Navin, Sanjay Kumarand Swami V. K. (2022) AStudy of Corrosion Inhibition
Effect of Pyridine Based Schiff
Base on Iron Metal in 0.5M
HCL, Journal of Global
Resources, Vol. 08 (02)DOI:
10.46587/JGR.2022.v08i02.013

Received: 15 May 2022
Reviewed: 30 May 2022
Revised: 11 June 2022
Final Accepted: 25 June 2022

Abstract: In this research study Schiff base (E)-N-(5bromopyridin-2-yl)-1-(4-ethylphenyl) methanimine (BPEPM)
synthesized by condensation of 4-ethyl benzaldehyde and 2amino-5-bromopyridine. The Schiff base was characterized byelemental analysis, IR and NMR spectroscopic methods. The
corrosion inhibition eﬀect of Schiff base BPEPM on thecorrosion of iron in 0.5M HCl was studied by using mass loss
method. The mass loss parameter like corrosion rate, inhibition
efficiency and surface coverage show that Schiff base BPEPM
is an efficient inhibitor for iron corrosion in 0.5M HCl solution.
The surface coverage and inhibition efficiency increase withconcentration of Schiff base BPEPM increases. In corrosive
medium inhibitor instantaneously forms a protecting layer oniron surface and retards the corrosion reaction. The plot log(𝜽/1-𝜽) versus logC (mol/L) show linearity it means adsorptionof inhibitor obey Langmuir adsorption isotherm pattern. Theinhibition efficiency of inhibitor increases with time duration. In72-hour time duration Maximum inhibition eﬃciency (95.7%) isshown towards iron corrosion at highest concentration ofinhibitor (5X10-5M).
Key words: Schiff Base, Corrosion Rate, Adsorption, Iron,
Mass Loss Method

Journal of Global Resources, July 2022, Volume 08 (02) Navin Maharia, Sanjay Kumar and Dr. V. K. Swami P a g e | 1 0 6

Introduction
Corrosion of material is a most observed process which occurs in nature. In corrosion process
metal reacts with its environment (humidity, gases, acid, alkaline etc.) and convert into the morestable form such as sulphide oxide etc. Corrosion has direct and indirect impact on economy,environment, materials and lives. It causes huge losses to building, automobiles, industries andtheir services [1-7]. Iron and its alloys which are widely used in a lot of industrial processes could
corrode during these acidic applications particularly with the use of hydrochloric acid and sulphuricacid [8]. During acid handling in industrial processes metals get corroded. Different corrosion
protection methods widely used in present time like using paints, coating and anodic protection.
But these methods are costly, so the use of organic inhibitor is one of the most convenientmethods for protection against corrosion to protect metal dissolution and acid consumption [9].
Those organic compounds which containing a heteroatom (N, O and S) and aromatic ring in theirstructure having excellent adsorption ability towards transition elements and act as efficientcorrosion inhibitors for metal corrosion in acidic medium [10-11]. The use of synthetic inhibitors
having environmental issues and they also modified structural properties of metal surface. Thus
it is big challenge to the researcher towards developing low cost and environmentally safe
corrosion inhibitors in present days [12-13].
Schiff bases are most widely used organic compounds in different field of science. Schiffbases widely tested as corrosion inhibitor for metals in acidic medium by many researchers. In
recent years, Thiourea, thiophene, pyridine, thiazole, phenol, thiasemicarbazide and itsderivatives have been examined as corrosion inhibitor for metals in acidic medium for more thanfour decades [14-22]. The Schiff base of pyridine (BPEPM) is nontoxic, soluble in aqueous media,
relatively cheap and easy to produce at high purity. These all properties would justify the use ofSchiff base (E)-N-(5-bromopyridin-2-yl)-1-(4-ethylphenyl) methanimine (BPEPM) as corrosion
inhibitor towards iron corrosion in acidic medium (0.5N HCl).
MATERIAL AND METHODS
Synthesis of (E)-N-(5-bromopyridin-2-yl)-1-(4-ethylphenyl) Methanimine (BPEPM)
Analytical grade reagents were used during synthesis. The Schiff base BPEPM was synthesized
and characterized on the basis of past reported study [23-29]. Schiff base (E)-N-(5-bromopyridin2-yl)-1-(4-ethylphenyl) methanimine (BPEPM) synthesized by condensation of 4-ethyl
benzaldehyde with 2-amino-5-bromopyridine. During synthesis process 2-amino-5-bromopyridine(0.1mole) and 4-ethyl benzaldehyde (0.1mole) dissolved in minimum quantity of ethanol has beentaken in round bottom flask. The mixture has been refluxed over heating mantle for 7 to 8 hours,
it was then cooled and resulting bright yellow-colored crystals of BPEPM (M.P. 80oC). The methodof synthesis is summarized in fig. (1).
Figure 01: Reaction Scheme

Journal of Global Resources, July 2022, Volume 08 (02) Navin Maharia, Sanjay Kumar and Dr. V. K. Swami P a g e | 1 0 7

Characterization of BPEPM
The Schiff base was characterized by elemental analysis, IR and NMR studies. The elemental
study shows the presence of C (59.71%), H (4.20%), N (9.1%) and Br (26.40%) in the structureof synthesized Schiff base. In the IR (Infra-red) spectra (fig. 4) of Schiff base band of azomethineυ(C=N) group observed at 1599.2 cm-1. In the NMR (Nuclear Magnetic Resonance) spectrum ofBPEPM (fig. 5) various signals like -CH3,-CH2,-CH=N, Ar-H were observed at 1.2772, 2.7363,7.3312, and 8.5232 𝛿(𝑝𝑝𝑚).
Experimental
Mass loss method is a fundamental method to study the mass loss during corrosion process. In
this method, iron specimens in the form of small coupons (size 3.0cm x 2.5cm x 0.1 cm) are
exposed to the corrosive media 0.5N HCl [in presence and absence of Schiff base BPEPM(0.01N)] for a stipulated period of time (4 hrs. to 72 hrs.) and the loss in weight for the specimen
is calculated. All corrosion parameters calculated by mass loss method shown in table 1.
The corrosion inhibition eﬃciency (η %) was calculated asη % = 100 (ΔMA – ΔMSB)/ ΔMA
Where, ΔMA = Mass loss of metal in acidic medium solution.
ΔMSB= Mass loss of metal in presence of Schiff base.
The degree of Surface coverage (𝜃) of metal specimen by inhibitor was calculated as:
𝜃 = (ΔMA – ΔMSB)/ ΔMA
The corrosion rates can be calculated by the following equation:
Corrosion rate (mm/yr) = (Mass loss x 87.6)/ DATWhere, D = density of iron
A = surface area of iron
T = immersion time
Result and Discussion
The corrosion inhibition of metals by organic inhibitors depends on various factors such as
electronic structure of inhibitor, concentration of inhibitor and immersion time. In this researchstudy we examine mainly eﬀect of two factors namely immersion time and inhibitor concentrationon corrosion inhibition process of iron metal in 0.5 N HCl. Immersion time can play an importantrole in the prevention of corrosion process. Inhibition performance of BPEPM increases by rising
exposure time or immersion time. The surface coverage and inhibition efficiency increase withconcentration of Schiff base BPEPM increases. Consequently, inhibition efficiency values
increase with the increase the concentration of inhibitor and maximum Inhibition eﬃciency is
95.7% shown at 5% (5X10-5M) inhibitor concentration. Inhibitor forms a monolayer by adsorption
on iron surface and retards corrosion rate. The plot log (𝜽/1-𝜽) versus logC (mol/L) show linearity
it means adsorption of inhibitor obey Langmuir adsorption isotherm pattern.
Conclusion
The eﬃciency of synthesized Schiff base BPEPM for corrosion inhibition of iron metal in acidic
media have been studies. Conclusions of study are:
• The inhibition efficiency of inhibitor increases with concentration.
• The inhibition efficiency increases according increasing immersion time exposure it means
it is effective over long range of time.
• The inhibitor obeys Langmuir adsorption isotherm pattern during inhibition process.
• This Schiff base act as effective inhibitor for iron corrosion in 0.5M HCl medium.
Journal of Global Resources, July 2022, Volume 08 (02) Navin Maharia, Sanjay Kumar and Dr. V. K. Swami P a g e | 1 0 8

Table 01: Schiff base Concentration (SBC), Mass Loss (ΔM) in mg, Inhibition Efficiency (η), Surface Coverage(𝜽) and Corrosion Rate (CR) in mm/year for Iron Metal in presence of Schiff base BPEPM at different TimeIntervalSBC(%)
Blank
12354 hours
ΔM
(mg)

η(%)

𝜃

1.89.91.66.50.25

…
5265
73
86

…
.52.65.73.86

24 hours
CR(mm/yr)

ΔM
(mg)

η

7.0
3.3
2.4
1.8.923.8
1.7
1.3.90
.40

…
55
65
7689

48 hours
CR𝜃

(%)

…
.55.65.76.89

η
(%)

𝜃

(mm/yr)

ΔM
(mg)

2.34
1.05.803
.556
.247

4.5
1.9
1.5.80
.31

…
5766
82
93

…
.57.66.82.93

72 hoursCRη(%)

𝜃(mm/yr)ΔM(mg)

1.39.587.463.247.095

5.7
2.3
1.8.95.24…
58.7
68.4
83.3
95.7

…
.58.68.83.95

CR(mm/yr)

1.17.484.370.195.049

Inhibition efficiency(%)

Figure 02: The Graph Inhibition Efficiency v/s Concentration of Schiff base (%) atdifferent Time Interval For Iron in 0.5M HCl
120

10080604 hr
24 hr
48 hr

402001235Concentration of Schiff base (%)
Figure 03: Langmuir Adsorption Isotherm for Iron at different Time Interval in
Presence of Schiff Base in 0.5 M HCllog (𝜽/1-𝜽)1.54 hr
24 hr
48 hr
72 hr

10.50-4-3.6989-3.5228-3.301logC(mol/L)
Figure 4: IR spectrum of BPEPM

Journal of Global Resources, July 2022, Volume 08 (02) Navin Maharia, Sanjay Kumar and Dr. V. K. Swami P a g e | 1 0 9

Figure 5: NMR spectrum of BPEPM

References
1.
2.
3.
4.

Ahamad, I., Prasad, R., Quraishi, M.A. (2010). Corrosion Science, 52, 3033-3041.
Al–Bayati S, Rasheed A, Zuhair E, Abid K and Khamis W, (2018). American Journal of Chemistry, 8(1)Ansari K R, Quraishi M A and Singh A, (2014). Corrosion Science, 79, 5-15.
Chetana P R, Somashekar M N, Srinatha B S, Policegoudra R S, Aradhya S M and Rao R, (2013).
ISRN Inorganic Chemistry, 1-11.
5. Desai P S and Indorwala N S, (2015). Research Journal of Chemical Sciences, 5(3) 30-36.
6. Fareles M, Keles H and Keles M, (2015). Corrosion Science, 98, 223-232.
7. Ghazoui A, Bencaht N, Al-Deyab S, Zarrouk A, Hammouti B, Ramdani M and Guenbour M, (2013). Int.
J. Electrochem. Sci., 8 2272 – 2292.
8. Jevaprabha C, Sathiyaharayanan S and Venkatacha G J, (2006). Appl. Polymer Science, 101(4) 2144.
9. Joseph X, Rajendra N, (2011). Inter J of Electrochem Science, 6 348.
10. Kajal A, Bala S, Kamboj S, Sharma N and Saini V, (2013). Journal of Catalysts, 1-14.
11. Karthiga N, Rajendran S, Prabhakar P and Rathish R J, (2015). Int. J. Nano Corrosion Science &Engineering, 2(4) 31-49.
12. Karthik G and Sundaravadivelu M, (2016). Egyptian Journal of Petroleum, 25 183-191.
13. Khaleel H, Ateeq A and Ali A, (2018). International Journal of Applied Engineering Research, 13(6).
14. Koch G, (2016). NACE International IMPACT, Houston, Texas, USA, 1-10.
15. Kosaria A, Moayeda M H, Davoodib A, Parvizia R, Momenia M, Eshghic H and Moradic H, (2014).
Corrosion Science, 78,138–150.
16. Kumar S and Swami V K, (2020). Journal of Advanced Scientific Research, 11(4) 337-340.
17. Mathur R, Pareek M and Swami V K, (2018). Global Journal for Res. Ana., 7(2) 2277-8160.
18. Pareek M and Swami V K, (2018). Indian Journal of Research, 7(7) 2250-1991.
19. Parrey I R and Hashmi A, Canadian Chemical Transactions, 3(2015) 65-71.
20. Popoola L T, Grema A S, Latinwo G K, Gutti B and Balogun A S, (2013). International Journal ofIndustrial Chemistry, 4 2-15.
21. Roberge R, (2020). Corrosion Accidents, Corrosion Doctors.
22. Shukla S N, Gaur P, Vaidya P, Chaurasia B, Jhariya S and Dehariya D, (2018). International Journalof Basic and Applied Chemical Sciences, 8(2) 1-19.
23. Sonnekar V S, Jadhav W N, Dake S A, Dhole S G, Narwade S and Pawar R P, (2014). Eur. Chem.
Bull., 3(8) 792-797.
24. Sorkabi H A, Seifzadeh D and Hosseini M G, (2008). Corrosion Science, 50, 3363.
25. Takjoo R, Akbari A, Ahmadi M, Rudbari H A and Bruno G, (2013). Cent. Eur. J. Chem., 11(11) 1844.
26. Xu B, Yang W, Liu Y, Yin X, Gong W and Chen Y, (2014). Corrosion Science, 78, 260-268.

Journal of Global Resources, July 2022, Volume 08 (02) Navin Maharia, Sanjay Kumar and Dr. V. K. Swami P a g e | 1 1 0