Highly Hydrophobic Polyurethane Coatings Modified with an Organosilicon Block Copolymer and Amino-Functionalized Nano/Microdispersed SiO2–NH2

The joint effect exerted on the hydrophobic properties of two-component polyurethane coatings by SiO2–NH2 particles prepared from tetraethoxysilane and 3-aminopropyltriethoxysilane using the sol–gel procedure and by an organosilicon block copolymer was studied. The structure and size distribution of particles were determined by Fourier IR spectroscopy, differential thermal analysis, and laser light scattering. Introduction of SiO2–NH2 particles leads to an increase in the roughness and change in topography of the polyurethane coating surface, which was proved by atomic force microscopy and scanning electron microscopy. Variation of the content of the organosilicon block copolymer influences the SiO2–NH2 particle-size distribution in the composite, the surface topography, and wetting of the coatings and allows preparation of highly hydrophobic polyurethane coatings with the contact angle and hysteresis of 166.2° and 11.9°, respectively.