Anticorrosive properties of PANI–ATMP polymer containing organic coating

The conducting polymer polyaniline–amino trimethylene phosphonic acid (PANI–ATMP) was prepared by chemical oxidative method using ammonium persulphate. The polymer was characterized by FTIR, UV and X-ray fluorescence spectroscopy and XRD. The conductivity of the polymer was measured by four probe resistivity meter. The polymer was dispersed in epoxy resin and the corrosion protection property of the coating for steel has been evaluated by salt spray, open circuit potential measurements and EIS. It has been found that the open circuit potentials of coated steel have been shifted to noble direction after the initial shift in the active direction in 3% NaCl. Besides, the charge transfer resistance values have been found to increase with time due to passivation of steel by PANI–ATMP pigment, indicating the protective nature of the coating.