Photostabilization of wood flour filled/polyvinyl chloride composites by addition of pigments during natural weathering

Natural weathering of Wood-Plastic Composites (WPCs) is a casual problem for outdoor applications. Surface properties of the WPCs are affected by natural weathering. Any changes in these properties could be prohibited by pigments as additives in WPCs. The main objective of the current research work was to apply rutile- titanium dioxide and iron oxide as pigments in wood-flour-filled/poly vinyl chloride composites as additives to study their effects on surface properties during natural weathering, such as variations in colors, contact angle, as well as mechanical properties. Surface properties were analyzed within nine month periods of natural weathering. The results showed that the TiO2 prevented lightening of the products and protected the surface from micro-cracks during the weathering. Any added titanium dioxide could also reduce color changes up to 90% versus untreated samples. The amount of protection was also influenced by concentration of TiO2.