Photoaging and stabilization of rigid PVC/wood‐fiber composites

Abstract

AbstractUltraviolet (UV) weathering performance of unpigmented and rutile titanium dioxide pigmented rigid polyvinyl chloride (PVC)/wood‐fiber composites has been studied. The composite samples were manufactured by dry‐blending PVC, wood fibers, and other processing additives in a high‐intensity mixer. The dry‐blended compounds were extruded and compression molded into panel samples. The manufactured samples were artificially weathered using laboratory accelerated UV tests. Composite samples were exposed to 340‐nm fluorescent UV lamps and assessed every 200 h, for a total of 1200 h of accelerated weathering. Each assessment consisted of a visual examination of surface roughness or erosion, a contact angle measurement, a FTIR collection, and a color measurement. The experimental results indicated that wood fibers are effective sensitizers and that their incorporation into a rigid PVC matrix has a deleterious effect on the ability of the matrix to resist degradation caused ultraviolet irradiation. The light stability of these composites could be improved quite efficiently with the addition of rutile titanium dioxide photoactive pigment during formulation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1943–1950, 2001