Photostabilization of poly(vinyl chloride) by protective coatings

The light stability of poly(vinyl chloride) plates has been substantially increased by protecting their surface with a UV-cured acrylic clearcoat containing both a UV absorber and a HALS radical scavenger. To ensure a long-lasting adhesion, the coating was photochemically grafted onto the PVC substrate. The coated PVC sample remained transparent, non-colored, and glossy upon accelerated QUV-B weathering for up to 3000 hours. An additional advantage of this method of photostabilization is to improve some of the surface properties of the coated polymer, such as its resistance to solvents, abrasion, and scratching. The method was also successfully used to recover highly photodegraded PVC and make it even more weathering-resistant than the original polymer.