| Abstract: | The water‐resistance properties of wood‐fiber‐reinforced recycled plastic composites (WRPCs) prepared from postconsumer high‐density polyethylene (HDPE) and wood fibers from saw mills were studied. Three methods consisting of an alkaline method (AM), a silane method (SM), and a combination of the alkaline and silane methods (ASM) were used to modify the wood fibers. The effects of fiber/matrix mix ratio and surface treatment on the moisture content, thickness swelling, and flexural strength change of the WRPCs, before and after immersion in 60°C water for 8 weeks, were studied and analyzed. The flexural fractured surfaces of the WRPCs before and after immersion in hot water were examined, and the fracture mechanism of the WRPCs was discussed. The results showed that the different surface treatments of the wood fibers had significant effects on the moisture content, thickness swelling, and flexural strength of the WRPCs after a long immersion time in hot water. For WRPCs treated by ASM, the moisture content was the lowest, the thickness swelling was at a minimum, and the flexural strength was the highest. Higher water absorption of composites with fiber treated by the AM or SM methods, as compared to those treated by ASM, could be attributed to the incomplete adhesion and wettability between the wood fibers and the polymer matrix, which may have caused more gaps and flaws at the interface. J. VINYL ADDIT. TECHNOL., 2008. © 2008 Society of Plastics Engineers. |
