The anticorrosion properties of pigments based on molybdates and tungstates surface-modified with conducting polymers

The objective of this work was to examine the properties of molybdate or tungstate based pigments whose surface has been coated with a conductive polymer, viz. either polyaniline phosphate (PANI) or polypyrrole phosphate (PPY), if used as pigments in organic coating materials. The anticorrosion pigments were prepared by high-temperature solid-state synthesis from the respective oxides, carbonates. The composite pigments (pigment/conductive polymer) were dispersed in a solvent-type epoxy-ester resin binder to obtain a series of paints whose anticorrosion properties were assessed by means of corrosion tests in accelerated corrosion test and by the linear polarisation method. Focus was on the anticorrosion properties of the paints depending on the pigment surface treatment, initial pigment composition, and pigment volume concentration (PVC) in the paint. The surface-treated pigment particles were expected to have a favourable effect on the anticorrosion and the mechanical properties of epoxy-ester resin based paints.