Sol-Gel Hybrid Coatings for Wood Products with Improved Surface Durability and Repellence Properties
Sol-gel hybrid coatings provide a new approach to improve surface properties of different materials. These coatings can be applied on metals, ceramics, glass, polymers, concrete and even on wood. Due to the inorganic components, the inorganic/organic hybrid coatings possess high thermal and mechanical stability, whereas the organic components are responsible for the flexibility and film-forming nature of the coatings. By tailoring the composition, thin hybrid coatings with high abrasion and scratch resistance can be created.1
Wood as a renewable and economical natural resource is one of the most important raw materials for a variety of furnishing and building applications. The appealing appearance and feel of wood and wood composite surfaces are most preferably protected with thin and transparent coatings that do not remarkably change the appearance of the substrate. A sol-gel technique enables formation of such coatings with a thickness of only a few microns. Sol-gel deposition has been successfully used to treat wood with alkoxysilanes in order to protect wood against weathering.2 In addition, sol-gel deposition of alkoxysilanes on wooden surfaces is suggested to result in a polysiloxane network that is covalently bonded to the substrate.2-4 Furthermore, treatment parameters, i.e., curing temperature of the coatings, can be adjusted so that no thermal degradation takes place in the substrate.