Effects of filler-filler and polymer-filler interactions on rheological and mechanical properties of HDPE-wood composites

Abstract

High-density polyethylene (HDPE)-wood composite samples were prepared using a twin-screw extruder. Improved filler-filler interaction was achieved by increasing the wood content, whereas improved polymerfiller interaction was obtained by adding the eompatibilizer and increasing the melt index of HDPE, respectively. Then, effects of filler-filler and polymer-filler interactions on dynamic rheological and mechanical properties of the composites were investigated. The results demonstrated that enhanced filler-filler interaction induced the agglomeration of wood particles, which increased the storage modulus and complex viscosity of composites and decreased their tensile strength, elongation at break, and notched impact strength because of the stress concentration. Stronger polymer-filler interaction resulted in higher storage modulus and complex viscosity and increased the tensile and impact strengths due to good stress transfer. The main reasons for the results were analyzed. © 2008 Wiley Periodicals, Inc.