No abstract

The existing methods of confering hydrophobic properties to various building materials are considered. Obtaining special, including hydrophobic, properties of water-emulsion paints is a very relevant task. Previously, a method was developed for producing an emulsion of a polysiloxane stabilized with polyvinyl alcohol. The paper describes the possibility of using a hydrophobisating emulsion of polyhydrosiloxane as a functional additive for an acrylic water-dispersion paint. This emulsion is capable of forming coatings on dense and porous surfaces with an adjustable contact angle up to 105 °. The use of this emulsion, with its sufficient coalescence for volumetric hydrophobization of coatings, makes it possible to obtain a high contact angle on the surface. In the paper, it was assumed that the partial introduction of small amounts (up to 10 %) of a hydrophobizing emulsion into water-dispersion paints would allow achieving the contact angle of wetting for similar coatings consisting exclusively of emulsion. It is shown that the introduction of small amounts of a hydrophobizing emulsion with an auxiliary coalescing action of ethylene glycol makes it possible to impart hydrophobic properties to the surface of the resulting coating. When the optimum concentration of ethylene glycol in the coating is reached, dissolution and transport (yield) of polysiloxane to the surface is ensured. The research carried out made it possible to develop a paint composition with a hydrophobizing emulsion with a contact wetting angle of about 100 °, which ensured the hydrophobicity of the previously hydrophilic coating of a water-dispersion acrylic paint.