keywords: Acid corrosion, acid fluids, corrosion inhibitor, Delonix regia, mild steel
The corrosion inhibition properties of Delonix regia leaf extract (DLE), flower extract (DFE) and seed extract (DSE) in 0.5M HCl solutions were studied using weight loss technique. Delonixregia extracts inhibited the corrosion of mild steel in HCl solution. The inhibition efficiency increased with increasing concentration of the extracts at 30oC. The seed extract (DSE) was found to be more effective than both the leaf (DLE) and flower extracts (DFE) at the lowest concentration. The results obtained revealed that the adsorption of the inhibitor molecule onto mild steel surface accords with Langmuir adsorption isotherm.
Abdel-Gaber AM, Abd-El-Nabey BA, Sidahmed IM, El-Zayady AM & Saadawy M 2006. Inhibition action of some plant extracts on the corrosion of steel in acidic media. Corrosion Science, 48: 2765-2779. Abiola OK, Aliyu AOC & Muhammed S 2016. Eco-friendly corrosion inhibitors: Effect of Delonixregia extract on corrosion and kinetics of corrosion process of aluminium alloy 2S in HCl solution. African Corrosion J., 2: 11 – 16. Abiola OK, Aliyu AOC, Elemike EE & Adeyemi O 2015. Eco-friendly corrosion inhibitor from TagetespatulaL. for aluminium alloy (3SR) in acid fluid used in industrial operations. NISEB Journal, 15: 25 – 28. Abiola OK & James AO 2010. The effects of Aloe vera extract on corrosion kinetics of corrosion process of zinc in HCl solution. Corrosion Science, 52: 661 – 664. Abiola OK, John MO, Asekunowo PO, Okafor PC & James AO 2011. 3-(4-amino-2-2methyl-5-pyrimidylmethyl)-4-methylthiazolium chloride as green corrosion inhibitor of copper in HNO3 solution and its adsorption characteristics. Green Chemistry Letters & Reviews, 4: 273 – 279. Abiola OK, Odin EM, Olowoyo DN & Adeloye TA 2011. GossipiumhirsutumL. extract as green corrosion inhibitor for aluminium in HCl solution. Bull. Chem. Soc. Ethiop., 25: 475-480. Abiola OK &Oforka NC 2002. Inhibition of the Corrosion of mild steel in hydrochloric acid by (4-amino-2-methyl-5-pyrimidinyl methylthio) acetic acid and its precursor. Journal of Corrosion Sci. & Engr., 3: 1-10. Abiola OK &Oforka NC 2004. Adsorption of (4-amino-2-methyl-5-pyrimidinyl methylthio) acetic acid on mild steel from Hydrochloric acid solution (HCl) – part 1. Materials Chemistry & Physics 83: 315-322. Abiola OK, Oforka NC, Ifelebuegu AO, Fasina TM & Babatunde AI 2009. Effect of diphenylthiocarbazone and diphenylcarbazone on acid corrosion of aluminium in HCI solution – Part 1. J. Scient. Res. & Devt., 11: 1 – 8. Abiola OK, Oforka NC, Ebenso EE & Nwinuka NM 2007. Eco-friendly corrosion inhibitors: the inhibitive action of DelonixRegia on the corrosion of aluminium in acidic media. Anti – Corrosion Methods and Materials, 54: 219 – 224. Abiola OK & Tobun Y 2010. CocosnuciferaL. water as green corrosion inhibitor for acid corrosion of aluminium in HCl solution. Chinese Chemical Letters, 21: 1449-1452. Babatunde AI, Ogundele O, Oyebola OT & Abiola OK 2012. The inhibitive effect of Irvingiagabonensis extract on the corrosion of aluminium in 1 M HCl solution. Advances in Appl. Sci. Res., 3: 3944 – 3949. Bhawsar J, Jain PK & Jain P 2015. Experimental and computational studies of Nicotinatabacum leaves extract as green corrosion inhibitor for mild steel in acidic medium. Alexandria Engr. J., 54: 769-775. Chou CH & Lev LL 1992. Allelopathic substances and interactions of Delonixregia. J. Chem. Ecol., 18: 2285 – 2295. Noor EA 2006. The inhibition of mild steel corrosion in phosphoric acid solutions by some N – heterocyclic compounds in salt form. Corrosion Science, 47: 33 – 35. Obi- Egbedi NO, Obot IB & Umoren SA 2012. SpondiaMonmbinL. as green corrosion inhibitor for aluminium in sulphuric acid: Correlation between inhibitive effect and electronic properties of extracts of major constituents using density functional theory. Arabian J. Chem., 5: 351 – 373. Sharma S & Arora S 2015. Phytochemicals and pharmaceutical potential of Delonixregia (Bojer ex hook). Int. J. Pharmacy & Pharmac. Sci., 7: 17-29.