Anticorrosion and physical properties of organic coatings containing perovskites surface modified by polyaniline or polypyrrole phosphates

The work describes the properties of perovskites pigments subjected to surface treatment with conductive polymers for use in protective coatings. The perovskites (XYO3; X = Zn, Ca, Sr; Y = Ti, Mn) were synthesised by high-temperature solid-phase reaction, and their surface was modified with a conductive polymer, specifically polyaniline phosphate (PANI) or polypyrrole phosphate (PPy), by chemical oxidative polymerisation. Conductive polymers are currently attracting considerable interest in a number of sectors, among them the paint industry owing to their non-toxicity and high stability. Paints consisting of a solvent-based epoxy-ester resin as the binder and the above-mentioned perovskite/PANI/PPy pigments were formulated. Corrosion resistance of the coatings was evaluated in dependence on the type of particle surface treatment with the conductive polymer, chemical composition of the pigment, and pigment volume concentration (PVC) in simulated corrosive atmospheres. The effect of the surface-treated inorganic composite pigments on the corrosion rate was investigated using electrochemical tests and accelerated corrosion tests.