Synergistic Effect of Halide Ions on the Corrosion Inhibition of Zinc in Hydrochloric Acid using Schiff base compound, 1-phenyl-2, 3-dimethyl-4-(benzylamino)pyrazole-5-one

The inhibitive effect of1-phenyl-2, 3-dimethyl-4-(benzylamino) pyrazole-5-one (PD(B)PO) on zinc corrosion in 0.1 M hydrochloric acid solution was studied using gravimetric method. The influence of halides viz., KCl, KBr and KI on the corrosion inhibition of PD(B)PO were also investigated. Results show that PD(B)PO alone provided satisfactory inhibition on the corrosion of zinc and it was also found that the inhibition efficiency increased synergistically in the presence of halide ions. The synergistic effect of halide ions was found to follow the order: KI > KBr > KCl. The inhibitor reduced the corrosion rate through adsorption process and obeyed the Freundlich adsorption isotherm.