Modification of epoxy-polyester and polyester powder coatings with silicone-acrylic
nanopowders – effect on surface properties of coatings (in English)
Polimery 2014, No 9, 643
The effect of modification with 3 wt % of nanopowders containing silicone-acrylic core-shell nanoparticles (size ca. 100 nm) on surface properties of epoxy-polyester and polyester powder coatings was investigated. Contact angle (CA) determinations, atomic force microscopy (AFM), confocal microscopy (CM), scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS), and X-ray photoelectron spectroscopy (XPS) were used to assess this effect. It was found that the modified coatings showed significantly higher CA values and significantly lower surface-free energy (SFE) values as compared to unmodified ones what could be explained by migration of silicone resin contained in nanopowder to the coating surface due to specific features of silicone polymer. Using XPS and EDS the presence of silicone on the surface was confirmed, and AFM of modified coatings revealed structures on the surface which could be attributed to nanoparticles of silicone resin. It was stated that the chemical structure of silicone resin influenced very much surface properties of the coatings.