Abstract The inhibitive and adsorptive characteristics of Januviafor the corrosion of zinc in HCl solutions have been studied using weight loss and gasometric methods of monitoring corrosion. The results obtained reveal that various concentrations of Januvia inhibited the corrosion of zinc in HCl between the temperature ranges of 303-333K. The inhibition efficiency of the inhibitor was found to decrease with temperature.Kinetic consideration reveals that the inhibited and uninhibited corrosion of zinc in the acid proceeded via first order kinetics with half-life values for the inhibited reactions being higher than values for the uninhibited systems. Thermodynamics consideration also reveals that this inhibitor is adsorbed on zinc surface by spontaneous physical adsorption mechanism. Values of free energy were lower than the threshold value of 40 kJ/mol. Also Temkin adsorption isotherms best described the adsorption characteristics of the inhibitor.
Keywords acid corrosion, weight loss, drugs, zinc, HCl