Hodnocení vlivu pøipravených polyanilinových solí na korozní vlastnosti organických povlakù/ Assessment of the impact of polyaniline salts on corrosion properties of organic coatings

At present, conductive polymers, including their notable representative - polyaniline (PANI), belong to the substances largely studied by various fields of science. Its usability for formulation of organic coatings is especially studied owing to their simple preparation, non-toxicity and high stability. The goal of this work is to assess the impact of polyaniline salts on corrosion properties of protective organic coatings by accelerated corrosion tests and the linear polarization technique (LPR). Polyaniline salts were prepared by oxidation polymerization in an acidic environments, where phosphoric acid (H₃PO₄), sulphuric acid (H₂SO₄) and hydrochloric acid (HCl) were used as the doping acids. In total, three types of polyaniline salts were prepared: PANI-H₃PO₄, PANI-H₂SO₄ and PANI-HCl that were characterised on the basis of physical-chemical methods and used for the formulation of organic coatings at the following levels of volume pigment concentration (VPC) = 0,1; 0,5; 1; 2; 3; 5; 10; 15; 20 % and the threshold volume pigment concentration (TVPC). The results of accelerated corrosion tests and the linear polarization method imply that both the type and volume concentration of polyaniline salts substantially affect the resulting corrosion properties of organic coatings. The results also indicate that namely the low levels of VPC of polyaniline salts positively influence the resulting corrosion properties compared to non-pigment organic coating.