J. Buchweishaija,*G.S. Mhinzi
Chemistry Department, University of Dar es Salaam, P.O. Box 35061, Dar es Salaam, Tanzânia
Received 6 June 2007; accepted 26 September 2007
Abstract
]]> The inhibitive effect of the gum exudate from Acacia seyal var. seyal on the corrosion of mild steel in drinking water was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results obtained show that gum exudates could serve as effective inhibitors for the corrosion of steel in drinking water network. The percentage inhibition increases with increasing the concentration of the gum at 30 oC. The percentage inhibitor efficiency above 95 % was attained at gum concentration ³400 ppm. The corrosion rates of steel and inhibition efficiencies of the gum exudates obtained from impedance and polarization measurements were in good agreement. Potentiodynamic polarization studies clearly reveal that the gum behaves predominantly as an anodic inhibitor. The study also shows that the inhibition efficiency was insignificantly affected by the temperature rise of the medium.Keywords: corrosion, inhibitor, acacia seyal, gum exudates, mild steel.
Texto disponível em PDF
Full text only in PDF format
References
]]>
1. A.M. Shams El din, Desalination 60 (1986) 75. [ Links ]
2. Guidelines for Drinking Water Quality, Vol. 1, WHO Publications, Geneva (1984).
3. P.B. Benett, W.S. Gerald, Proc. Int. Congr. Met. Corrosion 2 (1984)291.
4. T.H.Y. Tebbut, Principles of Water Quality Control, Pergamon Oxford, (1983), p. 76.
5. E. Khamis, N. AlAndis, Mat.-wiss. u. werkstofftech 33 (2002) 550.
6. H.I. Farooqi, M.A. Quraishi, P.A. Saini, Proceedings from European Federation of Corrosion (EUROCORR.’97) (1997) p. 247.
7. D. Mukherjee, J. Berchman, A. Rajsekkar, N. Sundarsanan, R. Mahalingam, S. Maruthamuthu, T. Thiruchelvam, D. Karaikudi, Anti-Corrosion Methods and Materials 44(3) (1997) 186.
8. A.M. Abdel-Gaber, B.A. Abd-El Nabey, I.M. Sidahmed, A.M. El-Zayady, M. Saadawy, Corrosion 62(4) (2006) 293.
9. JECFA/FAO; Specifications for Identity and Purity of Certain Food Additives, Food and Nutrition, Paper No. 49, FAO, Rome (1990).
10. M. Glicksman, Ed.; Food hydrocolloids, Vol. I and II, CRC Press, Inc., Boca Raton, Florida (1983).
]]> 11. D.M.W. Anderson, J.F. Stoddart, Carbohydr. Res. 2 (1966) 104.12. G. Trabanelli, Corrosion/89, Paper No 133 (1989).
13. O.L. Riggs, Theoretical aspects of corrosion inhibitors and inhibition in corrosion inhibitors, by C.C Nathan (Ed.) NACE (1973).
14. J.Y.N. Philip, J. Buchweishaija, and L.L. Mkayula, Tanz. J. Sci. 27 (2001) 9.
15. K. Juttner, Electrochim. Acta 35 (1990) 1501.
16. T. Szauer, A. Brand, Electrochim. Acta 26 (1981) 1219.
17. S. Sankarapapavinasam, F. Pushpanaden, M. Ahmed, Corros. Sci. 32 (1991) 193.
* Corresponding author. E-mail address: buchwe@chem.udsm.ac.tz
]]>