Effects of UV Weathering and a CeO2-Based Coating Layer on the Mechanical and Structural Changes of Wood/PVC Composites

摘要

Composite samples (WPVCs) of poly(vinyl chloride) (PVC) and wood flour were prepared in the PVC:wood weight ratio of 1:1, and the mechanical and structural changes of the composites were assessed in terms of UV aging time and condensation temperature. Acrylic coating containing cerium dioxide as a UV absorber was used for moderation of the mechanical and structural changes of PVC in the WPVC composites. The experimental results indicated that the tensile and flexural properties of the composites monotonically decreased when the aging time was increased, the effect being more pronounced at high condensation temperatures. It was observed that the polyene and yellowness indexes of the WPVC composites increased with UV aging time. The hydrophilicity of the WPVC was quantified by contact angle results and found to increase with increasing UV aging because of hydrogen bonding between —OH groups on the wood surfaces and water molecules. The acrylic coating containing CeO2 proposed in this work was sufficiently effective for maintaining the levels of hydrophilicity and mechanical properties of the WPVC composites. J. VINYL ADDIT. TECHNOL., 17:9-16, 2011.