Abstract: In order to investigate the UV aging properties of polyethylene (PE) based wood plastic composites, five types of plant fibers (poplar, rice husk, bamboo, rice straw and straw fibers) were incorporated into PE. The 120-day artificially accelerated UV aging test was carried on to analysis the color stability, quality, mechanical properties, and microstructure of five types of plant/PE composites before and after aging. The results indicate that artificial UV aging causes stable color difference changes, a decreased quality (during the first 30 days) followed by an increase, and poorer mechanical properties, with cracks and warping in the sections in the five PE-based wood plastic composites. After the 120 days of UV aging, the reductions of the flexural and tensile strength of poplar/PE composites are 32.04% and 16.31%, respectively; for the rice husk/PE composites, the reductions are 34.95% and 26.41%, respectively; for the rice bamboo/PE composites, the reductions are 27.57% and 21.85%, respectively; for the rice straw/PE composites, the reductions are 33.06% and 27.85%, respectively; and for the straw/PE composites, the reductions are 25.57% and 23.95%, respectively.

Key words: plant fibers, polyethylene, wood plastic composites, UV aging, mechanical properties