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The dependence of the corrosion-inhibiting properties of zinc-filled organic coatings on the nature of the conducting polymers and conducting pigments added and on the pigment particles’ surface coating with conducting polymer layers were investigated. The following materials were selected to examine the corrosion-inhibiting properties of the conducting polymers: polyaniline phosphate (PANI), polypyrrole (PPy), natural graphite, and carbon nanotubes. Conducting pigment combinations for application in coating materials were formulated by applying pigment volume concentrations (PVC) of 0.3%, 0.5% and 1%, which were completed with Zn dust to obtain pigment volume concentrations/critical pigment volume concentrations (PVC/CPVC) = 0.64. Such conducting pigment/zinc dust combinations represented corrosion inhibitors to be used as ingredients in protective coatings. Solvent-based 2K epoxy resin based coating materials containing the corrosion inhibitors so formulated were prepared to examine their anticorrosion properties. The pigmented coatings were subjected to laboratory corrosion tests in simulated corrosion atmospheres and to standardized mechanical resistance tests. The protective coatings so obtained exhibited a higher efficiency than coating materials containing zinc dust alone. The coating material containing carbon nanotubes at PVC = 1% and the coating material containing graphite coated with polypyrrole (C/PPy) at PVC = 0.5% emerged as the best zinc-filled coating materials with respect to their corrosion-inhibiting efficiency. Treatment with the conducting polymers had a beneficial effect on the coating materials’ mechanical properties. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this work was to identify the anticorrosive efficiency of synthesized, MeO/core pigments and of MeO pigments (MeO=ZnO, MgO) with varied morphology of particles. The synthesized MeO-type pigments displayed varied particle morphologies and the MeO/core core–shell pigments exhibited surface of particles made of zincite and periclase. These core–shell pigments have the properties of both the ZnO layer and of the core (wollastonite or graphite). Epoxy-ester based coatings containing the synthesized pigments were also formulated. To test the anticorrosion properties of the coatings, accelerated corrosion tests were carried out in the environment of condensed water, of NaCl mist, and of condensing water and SO2. The synthesized core–shell pigments have good anticorrosion efficiency in an epoxy-ester coating. [Copyright &y& Elsevier]

Abstract: The paper deals with research into the effects of treating the surface of pigment particles with polyaniline layers in anticorrosion paints. The pigments involved were tested in a form coated with a polyaniline layer and in an uncoated form. To study anticorrosion properties, mixed metal oxides with the structure of spinel and perovskite were synthesized to be later coated with polyaniline. Polyaniline was also used to coat the pigments based on iron trioxide, silicates and graphite. Water-borne, epoxy resin-based paints containing the pigments with and without the surface layer of polyaniline were formulated. The coatings were tested by means of laboratory corrosion tests. These involved corrosion tests accelerated with an increased temperature, with high atmospheric humidity, and with the presence of corroding substances such as SO2 and NaCl. [Copyright &y& Elsevier]

Abstract: Four pigments of various morphology – specularite, α-Fe2O3; goethite, α-FeO(OH); talc, (Mg3(OH)2(Si4O10); and graphite, C – without and with polyaniline phosphate coating, were tested for the anticorrosion performance in coatings produced by epoxy binders on iron plates. The corrosion tests were carried out in a condenser chamber with continuous water condensation or humidity with sulfur dioxide, and in a salt mist cabinet. Polyaniline coating of pigments in all cases improved the anticorrosion properties. Graphite coated with polyaniline performed the best among eight systems under investigation. The role of graphite and polyaniline conductivity in the electron transfers associated with corrosion of iron has been proposed. [Copyright &y& Elsevier]