investigating the effect of wood particle size on the rheology and physical-mechanical properties of wood-polypropylene composite

the growing interest in using natural fibers as reinforcing agents of polymer-based composites is mainly due to their advantages such as lower cost, lower density, ease of preparation, lower energy requirements for processing, biodegradability, wide availability and relative non-abrasiveness over traditional reinforcing fibers such as glass and carbon. in this study, wood-plastic composite (wpc) containing 40 wt % of wood was prepared using an intermeshing co-rotating twin screw extruder. the effect of wood particle size in three levels (100, 250, and 400 μm) was studied on the physicalmechanical properties of wpc such as: tensile properties, heat distortion temperature (hdt), melt flow index (mfi) and notched izod impact resistance. in addition, the rheological behaviors were studied as function of wood particle size. the data showed an increase in the modulus and a decrease in the tensile strength with increase of wood particle size while there was no considerable change in the elongation-at-break. the results also showed that mfi decreased and impact resistance increased with decreases of wood particle size. hdt was independent from variation of wood particle size. complex viscosity and storage modulus increased with decrease of wood particle size while tan δ did not change with variation of particle size.