Influence of UV stabilizers on photo-degradation of PVC/wood flour and PVC/corncob composites by natural weathering test

Abstract

Long-term exposure to sunlight of wood plastic composites (WPCs) leads to photo-degradation. Therefore, it is essential to develop the durability of products by adding UV stabilizers into WPCs. In this research, polyvinyl chloride (PVC) is a matrix and two types of fillers, which are teak wood and corncob with particle sizes 250-425 µm and a fixed content of 60 phr, were used. UV stabilizers used in this study were two types of commercial grade UV absorber. The samples were exposed to sunlight for 4 months. The color change and mechanical properties of samples were determined every week and every month, respectively by natural weathering test method. The results showed that UV stabilizers can delay the lightness change and the color change of PVC but did not significantly affect on PVC/composites. In addition, the lightness of PVC/teak wood flour (PVC/TWF) composites changed more than that of PVC/corncob (PVC/CC) composites after weathering test. Moreover, UV stabilizer can delay the loss in flexural and tensile properties of PVC and PVC composites. The type and loading of UV stabilizer had no significantly affect on the lightness change, flexural and tensile property loss.