2022 Volume 21 Issue 2 Pages 113-128
Wood plastic composites (WPCs) have been gaining market share in exterior materials, such as decking, owing to their good decay resisting properties. However, recently, as the domestic exterior market of WPCs has not been showing an increasing trend, the expansion of applications is required. In this study, WPCs with wood percentages of 60% to 75% were exposed to the marine environment to obtain basic knowledge about the WPCs deterioration in marine environments where they have not been used much. In particular, the influences of wood percentages in WPCs on its characteristics changes, such as discoloration, mass change, dimensional change, bending elasticity change, and surface chemical change due to deterioration, were examined. As a result, in the underwater exposure test, almost no feeding damage by marine borers was observed throughout the test period of 21 months, with several percentage levels of mass reduction. Furthermore, the flexural modulus decreased greatly at the early exposure stage as the WPC with higher wood percentages. However, in the splash zone exposure test conducted for 18 months, the WPC surfaces photodegraded and discolored greatly in the early exposure stage. Moreover, the flexural modulus showed a decreasing tendency similar to that in the underwater exposure test. However, the water contact time was shorter in the splash zone exposure test than in the undersea exposure test. Based on the results obtained, the availability of WPCs in the marine environment was discussed.
