Abstract: The PP/SF wood-plastic composites were prepared through masticating and melt-compounding. The effect of water immersion of SF on the mechanical properties, thermal properties and micro-structure of the wood-plastic composites was studied. When the SF content was 50 %, water immersion time was 8 d, the impact and flexural strengths of the wood-plastic composites decreased sharply, decreased by 33.74 % and 51.42 %, from 9.88 kJ/m2 and 21.02 MPa, respectively. The thermal stability of composites, crystallization rate and degree of crystallinity of PP were also decreased. All these changes were attributed to the water molecules diffused into the wood-plastic composites.

Key words: wood-plastic composite, sisal fiber, polypropylene, water resistance