CORROSION INHIBITORY ACTIVITY OF 1-(4-DIMETHYLBENZYLIDENE) AMINOTHIOUREA AND ITS METAL COMPLEX.

Abstract

The synthesis of 1-[4-(Dimethylamino)benzylidene]aminothiourea  from N-amino thiourea and 4-Dimethylamino Benzaldehyde  in  1:1 molar ratio and its complexation with  copper(II) chloride dehydrate, CuCl2.2H2O in  2:1 molar ratio respectively was carried out via refluxing method . Fourier transform infrared (FT-IR) spectroscopy was used to characterize both the Schiff base ligand and its copper(II) complex which revealed the formation of the Schiff base and  the metal complex. Melting points for both compounds were determined to verify the purity of the compounds. The corrosion inhibitory activity of both the ligand and its metal complex was also determined in 1M H2SO4 using weight loss method and their corrosion rates and inhibition efficiencies were obtained and compared. Results obtained showed that both compounds have inhibitory effect on  corrosion. It was also revealed that an increase in the concentration of the inhibitor leads to a decrease in weight loss of the mild steel thereby reducing the corrosion rate. It was observed that, at a ligand concentration of 0.021% to 0.11%,weight loss decreases from 12.16mg to 9.40mg after 30 mins leading to a total reduction in corrosion rate from 3.16mdd to 2.36mdd while the inhibition efficiency increased from 62.51% to 72.0% Keywords: Schiff base, metal complex, concentration, corrosion rate, inhibition efficiency.