Rheological Behavior of Hdpe-wood Flour Composites with Different Wood Contents

Rheological behavior of high-density polyethylene (HDPE)-wood flour composites with different wood contents was examined using steady shear sweep, oscillatory frequency sweep, creep test, and stress relaxation test. The samples were prepared using a melt compounding method in a twin-screw extruder. The results showed that the yield stress did not appear for the composites prepared under the processing conditions used in this work. Oscillatory frequency sweep showed that both storage and loss moduli of the composites increased with increasing wood content. However, they exhibited a plateau for the composites with wood contents higher than 30% at low frequency. The creep test showed that the composites with high wood content were difficult to deform. The relaxation modulus of the composites obtained from stress relaxation test increased with increasing the wood content.