Studies on the inhibition potentials of Cochlospermum tinctorium extract on acid corrosion of brass

摘要

The objective of the present studies was to investigate the inhibitive effect of Cochlospermum tinctorium extract (CTE) on the corrosion of brass in 0.5 M HCIO_4 by mass loss and gasometric measurement at various time intervals and temperature. Cochlospermum tinctorium a medicinal plant, containing phytochemicals is rich in sulphur and oxygen atoms which generally serve as inhibitive adsorption centres. The corrosion rate is remarkably lower in acid environment containing PAE compared with those in extract free solution. The inhibition efficiency (74.19 - 84.26 %) is concentration and temperature dependent. Thermodynamic parameters (, A ) were calculated using the adsorption isotherm. Activation parameters of the corrosion process () were also calculated from the corrosion rates obtained from temperature studies. The adsorption isotherm indicates that the adsorption of CTE inhibitor on the surface of brass is physisorption and the thermodynamic values obtained indicates spontaneous and exothermic corrosion processes. The significance of the studies showed that Cochlospermum tinctorium extract can serve as a source of cheap, biodegradable and environmentally friendly corrosion inhibitor.