Corrosion Inhibitive Effects of Coconut Water for Al 7075 Alloy in Acidic Medium

Abstract

Excess molar volumes, VE, at T = 303.15 K, have been measThe corrosion inhibitive effect of coconut water as an eco-friendly inhibitor for the corrosion control of Al 7075 alloy in 0.5 Molar solution of H2SO4 acid have been investigated using the weight loss method which is considered more informative than other laboratory techniques. The studies were carried out using 30-110ml of the coconut water. The test coupons were totally immersed in the corroding medium containing various concentration of the inhibitor at the time intervals of 24-192 hours. The results obtained showed that the concentration of the inhibitor in the corrodent impacted differently on the test coupons. The corrosion rate was found to decrease while the inhibitor efficiency increases as the inhibitor concentration was increased. The plateau of maximum inhibition efficiency of 89.07% and 81.57% was obtained at the concentration of 90ml and 110ml for 24hours and 48hours immersion time respectively. The study showed that coconut water possesses inhibiting properties for reducing the corrosion of Al 7075 alloy in the acidic medium.ured for binary liquid mixtures of ketocyclohexane (C6H10O) + dichloromethane (CH2Cl2), + trichloromethane (CHCl3), + l,2 dichloroethane (CH2ClCH2Cl), + trichloroethene (CHClCCl2), and + 1,1,1- trichloroethane (CCl3CH3). The values of VE have been fitted in appropriate equations using a least-squares method. VE has been found to be negative throughout the entire range of composition for mixtures of C6H10O + CH2Cl2, + CHCl3, + CHClCCl2, and + CCl3CH3. For C6H10O + CH2ClCH2Cl, VE has been found to be positive at lower mole fractions of C 6H10O, and negative at higher mole fractions. The results obtained have been discussed from the viewpoint of existence of specific interactions between the components.