Abstract: Two kinds of polypropylene/waste ground rubber tire (PP/WGRT) blends with different viscosities of PP as the matrix were prepared by melt blending using a self-developed chaotic mixing extruder. Phase morphology, rheological properties, and mechanical properties of PP/WGRT blends taken from four positions along the extruder were investigated. The results showed that along the extruder the size of the WGRT agglomerates decreased and their dispersion became increasingly uniform in PP matrix due to the chaotic mixing provided by the extruder in this work. This led to higher values of both the complex viscosity (η*) and storage modulus () of the blend samples taken from four positions than those of the corresponding PP. The values of η* and of the blend samples in the low frequency increased gradually along the extruder. The introduction of the WGRT obviously improved the impact strength of the PP with higher viscosity but slightly increased that of the PP with lower viscosity.

Key words: polypropylene;waste ground rubber tire, phase morphology, rheology behavior;mechanical properties