Abstract

ECO FRIENDLY EXTRACT OF PORTULACA QUADRIFIDA AS CORROSION INHIBITOR FOR CARBON STEEL IN 1M HYDROCHLORIC ACID SOLUTION

Dr. S. K. Selvaraj*

Abstract

Plant extracts as corrosion inhibitors are found as an alternative to synthetic organic compounds. The extract of Portulaca Quadrifida and its major active constituent namely, Kaempferol were investigated for their corrosion inhibition properties on mild steel in 1M hydrochloric acid solution using weight loss, electrochemical methods.The formulation consisting of 3mL of PortulacaQuadrifida Extract (PQE) and 50 ppm Zn2+ offers 95% inhibition efficiency to carbon steel immersed in 1M hydrochloric acid solution. Influence of duration of immersion on the Inhibition Efficiency of PQE-Zn2+ has been evaluated Potentiodynamic polarization investigations revealed that the inhibitors performed as mixed type inhibitors. The mechanistic aspects of corrosion inhibition have been investigated by polarization study and AC impedance spectra. The surface morphology and the roughness of the metal surface have been analysed by atomic force microscopy. The FT-IR reveals that the protective film is formed on the metal surface consists of Fe2+ - PQE complex and Zn(OH)2.

Keywords: Carbon steel, Synergism Parameter, Portulaca Quadrifida, Kaempferol, Protective film.