Abstract: Polypropylene (PP)/glass fiber(GF)composites were prepared by a co-rotating twin-screw extruder, and the effect of screw rotation on GF in the composites and the properties of composites was investigated. The results indicated that the content of GF increased with an increase of rotation speed and achieved a maximum value of 48.2 %. However,the fiber length tended to decrease gradually with increasing rotation speed. The tensile strength, bending strength, heat-resistant temperature and hardness of the composites were improved with the increase of rotation speed, but the impact strength showed a slow decline. The incorporation of maleic anhydride-grafted PP improved the fiber length significantly, and meanwhile, the GF content, tensile strength, bending strength, notched and no-notched impact strength increased 1.8 %,95.1 %,90.1 %,50 % and 110.4 %, respectively.

Key words: screw rotation, maleic anhydride-grafted polypropylene, polypropylene/glass fiber composite, glass fiber