ALKALOID EXTRACT OF ALNUS NEPALENSIS BARK AS GREEN INHIBITOR FOR MILD STEEL CORROSION IN 1 M H2SO4 SOLUTION
Date
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Amrit Campus
Abstract
Extraction of alkaloids from Alnus nepalensis bark has been successfully carried out,
and used as green inhibitor for mild steel corrosion exposed to 1 M H2SO4 solutoin.
Corrosion inhibition has been monitored by weight loss measurement and
electrochemical methods (open circuit potential method and potentiodynamic
polarization method). Alkaloids have been tested by two qualitative chemical
analysis: Mayers test and FTIR spectroscpic test. Weight loss measurement was
employed to study the inhibitor concentration and immersion time effect. Similarly,
temperature effect on inhibition efficiency was also carried out by this method. The
corrosion inhibition efficiency with concentration at the various time showed that the
maximum efficiency occurs at 3 h for 1000 ppm solution is 71.94 % at 25 C. These
results concluded that the inhibition efficiency was incresed with inhibitor
concentration.
Potentiodynamic polarization for 3 h immersed samples in the presence and absence
of inhibitors has been carried out. The maximum efficiency of immersed sample is
90.00 % for 1000 ppm solution. The corrosion potential density was decreased with
increase in concentration. The OCP measurement revealed that alkaloids acted as a
mixed type of inhibitor. The adsorption isotherm and theromdynamic parameters are
calculated and energy of activation (Ea) is found to be 74.48 kJ/mol. The positive
value of enthalpy indicated that the reaction involves is endothermic in nature.