Melt rheological properties of polypropylene–wood flour composites

Abstract This article presents study of melt rheological properties of composites of polypropylene (i‐PP) filled with wood flour (WF), at filler concentrations of 3–20 wt%. Results illustrate the effects of (i) filler concentration and (ii) shear stress or shear rates on melt viscosity and melt elasticity properties of the composites. Incorporation of WF intoi‐PP results in an increase of its melt viscosity and a decrease of melt elasticity such as die swell and first normal stress differences; these properties, however, depend on filler concentration. Processing temperature of the filledi‐PP increases as compared to the nonfilled polymer.