Effect of surface treatment of pigment particles with polypyrrole and polyaniline phosphate on their corrosion inhibiting properties in organic coatings

The effect of pigment particle surface treatment with conductive polymers on the corrosion inhibiting properties of organic paints was investigated. Mixed oxides possessing the spinel and perovskite structures were synthesised for the study. Natural graphite and pigments based on ferric oxide and silicate were studied. Coating materials based on a water-based epoxy resin were prepared for the investigation of the corrosion protection properties of the pigments, the surfaces of which had been provided with a conductive polymer layer. Laboratory corrosion tests were applied to the paint films. A commercial corrosion protection pigment, based on modified zinc phosphate, served as the corrosion protection efficiency standard. Polyaniline phosphate was found preferable to polypyrrole as the modifying agent of the pigment surface regarding the pigment's corrosion inhibiting efficiency. Surface treatment with the conductive polymers is also beneficial to the mechanical properties of the paint.