Recovery of photodegraded polymers by surface treatment

A two-step process has been developed in order to renovate highly photodegraded polymers. It was applied to clear and pigmented commercial PVC plates, which were exposed to accelerated weathering. The brown highly degraded top layer was first removed by sandpapering, which makes the color disappear and restores the original impact resistance of PVC. In a second step, a thin film of a UV-curable acrylic resin was sprayed onto the PVC plate, which thus recovered its initial transparency. After a 1s UV exposure, the coated PVC was found to exhibit an excellent resistance to chemicals, weathering and scratching. One of the distinct advantages of this new low-cost recycling process is that it is based on existing technologies and can be carried out directly on the plastic structures to be renovated.