A Study of Wire Croton as an Inhibitor of Mild Steel in HCL Using Electrochemical – SEM – GCMS and FTIR Measurements

The inhibition capability of aqueous extract of Codiaeum variegatum Brilliantissima – Zanzibar (Wire Croton – WC), (CVB-WC) on mild steel corrosion in 1 M HCl solution was studied using electrochemical polarization, Scanning Electron Microscopy (SEM), Fourier Transform-Infrared Spectrum (FT-IR) analysis and Gas Chromatrography-Mass Spectrometry (GC-MS) analysis. The inhibition efficiency extrapolated from potentiodynamic polarization curves showed that cold water extract of CVB-WC behaved mostly as mixed type inhibitor in hydrochloric acid. Scanning electron microscopy was used to characterize the surface morphology of uninhibited and inhibited mild steel specimens and the results show a remarkable inhibition of the corrosion process in the presence of the inhibitor. Analysis of the peaks of Fourier Transform-Infrared Spectrum (FT-IR) of the inhibitors indicated presence of functional groups containing Phosphorus, Oxygen, Nitrogen, -OH and -COOH while the peaks of the Gas Chromatrography – Mass Spectrometry (GC-MS) analysis is in agreement with the results of the FT-IR and indicate the presence of corrosion inhibiting compound such as Terpenes, Tannin, Alkaloid, Flavonoid and Phytate in different appreciable concentrations. An inhibition efficiency of 94.9 and 96.1% is reported for 16 and 67% volume concentration of the inhibitor from the electrochemical analysis.