Search for a command to run...
The paper presents the results of developing paint and varnish coatings for protecting metal bridge structures, featuring high durability under operating conditions. The focus is on preparing metal surfaces for painting, specifically developing a formulation for a pre-treatment composition prior to paint and varnish application. The composition is a solution based on mixed solvents, one of which is an ester and the other an aromatic hydrocarbon, containing nanomaterials. The specific solvents used in the composition, as well as the types and amounts of nanomaterials, depend on the type of film-forming agent in the applied paint and varnish. The conducted studies on a specific example of a composition formulation, including a solution based on mixed solvents (butyl acetate (52-55 wt.%) and toluene (45-48 wt.%), containing a concentrate with carbon nanotubes and silicon dioxide, in an amount of 0.01-0.2 wt.%, including 10 wt.% single-wall carbon nanotubes and silicon dioxide nanoparticles and 90 wt.% mixture of triethylene glycol dimethacrylate and alkylammonium salt of high-molecular copolymers showed that acrylic paint and varnish coatings acquire increased physical and mechanical properties (adhesive strength, abrasion resistance, resistance to deformation effects, etc.). At the same time, there is an increase in the dielectric constant of the coating (from 16.45 to 18.39), which characterizes its increased conductivity, as well as a decrease in the dielectric loss tangent (from 0.017 to 0.008), which indicates the production of antistatic coatings. The chemical resistance of the coatings increases, which characterizes their resistance to aggressive environments, expressed in better preservation of properties according to the criteria: change in gloss (hue), whitening, blistering, peeling, wrinkling. When considering the formation of interaction on the metal surface during its contact with the coating during surface treatment with nanomaterials, the following mechanisms of action of nanomaterials with a metal surface were revealed, which are consistent with the provisions of the electrical theory of adhesion and the theory of the physical chemistry of polymers: interaction of nanomaterials with surface atoms of the metal with the formation of electrovalent interaction by the donor-acceptor mechanism; Chemical interaction (chemisorption) of the active sites on the surface of carbon nanotubes with the metal surface layer. Industrial testing of the resulting solution yielded a positive result: after 28 months of operation, the coating obtained by surface treatment with the nanomaterial composition, compared to the untreated coating, performs its functions and exhibits superior decorative and protective properties. The technical and economic efficiency of the developed approach is ensured by improved adhesive-cohesive interaction of paint and varnish coatings, which creates conditions for extending their service life and periods between repairs; and by reducing resource and energy costs without compromising coating quality due to the use of a small amount of binary nanomaterials in the developed composition.