what Is polyurethane finish?

a polyurethane coating (pu coating , also known as Pu paint) is a high-qualityand long-lasting surface coating that is able to offer structural and aesthetic benefits for a variety of applications. This coating is popular for its resistance scratches, chemical, moisture corrosion, as well as the natural process of aging, the polyurethane coatings are made available in multiple forms including sheets, foam and blocks, beads, roofing tiles, shingles…