Hard coatings on polycarbonate plate by sol–gel reactions of melamine derivative, poly(vinyl alcohol), and silicates

Hard coatings were deposited on a polycarbonate plate using a sol–gel process with a melamine derivative, poly(vinyl alcohol) (PVA), and silicates and examined as potential substitutes for glass in cars. PVA was partially functionalized with (3-isocyanatopropyl)triethoxysilane, and the synthesized polymer was used to form a coating solution with methylated poly(melamine-co-formaldehyde), tetraethoxysilane, and methyltriethoxysilane. The coatings that contained both the melamine and silicate structures were deposited using a sol–gel process. The optimum conditions and formulation to obtain excellent physical properties of the coating were determined. Smooth coatings with the hardness of a 3H class pencil, excellent abrasion resistance and transparency were formed.