APPLICATION OF POLYMERIC DISPERSION FOR CLEANING SURFACE OF ARCHITECTURE MONUMENTS

The use of aqueous polymer dispersions of butyl acrylate-methyl-acrylate-methacrylic acid and polyvinyl acetate for purifying the surface of tiles of the 18th and 19th centuries, fragments of carved stone blocks of window frames XVII, bricks of the sixteenth and nineteenth centuries, and plaster brackets of the late nineteenth century, tiled tiles from the facade of the building of the city of Lviv, the areas of the surface of the Boim's chapel in Lviv, metal plates of models of coriand and stucco decor from the main building of the National University of Lviv Polytechnic. Contamination on the surface of these materials results from the chemical reactions of the surface with air, water and water solutions, components of exhaust gases of internal combustion engines, adsorption of atmospheric bombs and other substances, growth of molds and moss, they form chemical and intermolecular bonds with the surface layer and are characterized by different energy and strength. It is shown using a well-known film forming mechanism that surface contamination can be included in their composition. According to the known bonding energies during the formation of films from aqueous dispersions between the surface and the film, there are no chemical bonds, but only realized intermolecular interactions - orientation, induction and dispersion, and in the case of the use of a carboxyl-containing polymer - tangles with a significant ionic nature, which are close to hydrogen for durability. This makes it possible to state that the contamination that is held on the surface by intermolecular bonds can be included in the dispersion films and removed with them. The peculiarities of film formation on the surface of architectural monuments and their removal from the surface together with pollution are analyzed. Contaminants form micomolecular bonds with films of polymer dispersions during their formation and, accordingly, during film removal, there is an opposition between the bonds of particles of contamination with films and with a stone. If the contamination is kept by the chemical bonds, then during the film they will remain on the floor and if intermolecular - then removed with the film. This was also observed during the removal of films obtained from polymeric dispersions on purified surface. The considered technique allows you to quickly and easily clean the monuments without damaging their surface, as well as valuable lower layers. The materials used do not adversely affect the physical size and aesthetic properties of the monument. The used materials are easily accessible, do not harm human health and the environment. It should be noted that during restoration it is necessary to use a complex technique, conditioned by the uniqueness of monuments and features of contamination of its surface. It is also desirable to take into account the state of preservation of the work: deep structural changes, existing chips, cracks, shifted parts, layers of polychrome, etc..