Weathering performance of delignified pine-based polyvinyl chloride composites

The influence of pine fiber treatments on the color and chemical changes of polyvinyl chloride-based wood plastic composites exposed to outside and xenon-arc accelerated weathering was investigated. The wood plastic composites were produced from pine fiber (untreated control, acetone extracted, and holocellulose (delignified)) and polyvinyl chloride. Different analytical tools (colorimetry, microscopy, infrared spectroscopy, and gel permeation chromatography) were employed for weathered wood plastic composites characterization. The study showed that longer exposure time in both outside and accelerated weathering regimes caused an increase in color change and lightness, cracking, higher oxidation but decrease in wood (lignin) content of the weathered wood plastic composites’ surface for all the wood fiber types. The polyvinyl chloride molecular weight decreased with increase in exposure time of the composites. From this study, delignified wood fiber-based wood plastic composites had less color (lightness) change and reduced surface cracking with lowest weathered surface oxidation. Furthermore, relationships between accelerated and outside weathered wood plastic composite surfaces were observed.