CORROSION STUDIES WITH ANTIGONON LEPTOPUS IN 1M HCl
S.Aejitha 1, P P.K.Kasthuri 2andGeethamani 3
1 Department of Chemistry, Asian College of Engineering & Technology, Coimbatore- 641110, India
2 Department of Chemistry, L.R.G.Government Arts College for Women, Tirupur- 638604, India
3 Department of Chemistry, Sriguru Engineering College of Technology, Tamil Nadu, Coimbatore -641110, India
Correspondence should be addressed to S.Aejitha ,aejitha_subbaian@yahoo.co.in
ABSTRACT
The inhibition efficiency of an acid extract of Antigonon Leptopus used as corrosion inhibitor for mild steel in 1M HCl medium is inspected by weight loss, temperature and electrochemical studies in the presence and absence of extract . The polarization studies …show more content…
(1)
Wu –weight loss in the absence of inhibitor
WI –weight loss in the presence of inhibitor
2.3.1.Determination of corrosion rate
In this present study, the rate of dissolution of metal (CR) is expressed in American units, mpy (mils per year). The corrosion rate was calculated using the following expression (Eq.2).
Corrosion rate (CR) = (534 ×W)/DAT mpy (2)
Where, mpy -mils per year, W -Weight loss in mg, D-Density in g / cm2 (7.9g / cm2 for mild steel) , A-Area in square inch and T- immersion time in hours
2.3.2.Determination of activation energy (Ea)
Ea = - 2.303 RT x slope (3)
Where, Ea is the activation energy, T is the absolute temperature and R is the universal gas constant.
2.4.Electrochemical Method
To analyze the electrochemical feature of corrosion with the help of polarization cell. Polarization cell made up of three electrodes, platinum electrode, mild steel as working electrode and calomel electrode which were immersed in 1M HCl acid in with and with out inhibitor at room temperature …show more content…
The mild steel specimens, immersed in acid solutions in the presence and absence of inhibitor for 6 hour at room temperature were taken out washed carefully with doubly distilled water and dried. Then the surfaces were analyzed by using Shimadzu FTIR, Energy Dispersive X-ray fluorescence spectrometer and photographed at appropriate magnification.
3.RESULT AND DISCUSSION
3.1.Preliminary phytochemical screening of 1M HCl extract of Antigonon Leptopus
The results of the preliminary phytochemical screening are given in Table 1. The extract was found to contain alkaloids, terpenoids, Flavanoids,glycosides, Steroids and saponins. Phytochemical screening tests of the AL extract matches with the earlier work done by Johnson Marimuthu @ Antonisamy et al (2012).
Table1Preliminary phytochemical screening of HCl extract of AL
Plant AL
Tannins -
Alkaloids +
Triterpenoids +
Glycosides +
Flavanoids +
Saponins
S.Aejitha 1, P P.K.Kasthuri 2andGeethamani 3
1 Department of Chemistry, Asian College of Engineering & Technology, Coimbatore- 641110, India
2 Department of Chemistry, L.R.G.Government Arts College for Women, Tirupur- 638604, India
3 Department of Chemistry, Sriguru Engineering College of Technology, Tamil Nadu, Coimbatore -641110, India
Correspondence should be addressed to S.Aejitha ,aejitha_subbaian@yahoo.co.in
ABSTRACT
The inhibition efficiency of an acid extract of Antigonon Leptopus used as corrosion inhibitor for mild steel in 1M HCl medium is inspected by weight loss, temperature and electrochemical studies in the presence and absence of extract . The polarization studies …show more content…
(1)
Wu –weight loss in the absence of inhibitor
WI –weight loss in the presence of inhibitor
2.3.1.Determination of corrosion rate
In this present study, the rate of dissolution of metal (CR) is expressed in American units, mpy (mils per year). The corrosion rate was calculated using the following expression (Eq.2).
Corrosion rate (CR) = (534 ×W)/DAT mpy (2)
Where, mpy -mils per year, W -Weight loss in mg, D-Density in g / cm2 (7.9g / cm2 for mild steel) , A-Area in square inch and T- immersion time in hours
2.3.2.Determination of activation energy (Ea)
Ea = - 2.303 RT x slope (3)
Where, Ea is the activation energy, T is the absolute temperature and R is the universal gas constant.
2.4.Electrochemical Method
To analyze the electrochemical feature of corrosion with the help of polarization cell. Polarization cell made up of three electrodes, platinum electrode, mild steel as working electrode and calomel electrode which were immersed in 1M HCl acid in with and with out inhibitor at room temperature …show more content…
The mild steel specimens, immersed in acid solutions in the presence and absence of inhibitor for 6 hour at room temperature were taken out washed carefully with doubly distilled water and dried. Then the surfaces were analyzed by using Shimadzu FTIR, Energy Dispersive X-ray fluorescence spectrometer and photographed at appropriate magnification.
3.RESULT AND DISCUSSION
3.1.Preliminary phytochemical screening of 1M HCl extract of Antigonon Leptopus
The results of the preliminary phytochemical screening are given in Table 1. The extract was found to contain alkaloids, terpenoids, Flavanoids,glycosides, Steroids and saponins. Phytochemical screening tests of the AL extract matches with the earlier work done by Johnson Marimuthu @ Antonisamy et al (2012).
Table1Preliminary phytochemical screening of HCl extract of AL
Plant AL
Tannins -
Alkaloids +
Triterpenoids +
Glycosides +
Flavanoids +
Saponins