Properties of lignocellulosic material filled polypropylene bio-composites made with different manufacturing processes

Using polypropylene as the matrix polymer and rice-husk flour and wood flour as the reinforcing filler, the tensile and Izod impact properties of lignocellulosic filler reinforced polypropylene bio-composites made with different extruding systems were examined by assessing their mechanical properties and the morphology of the fracture surfaces. The test samples were injection molded, in order to determine the mechanical and morphological properties of the bio-composites made with two different extruding systems and at different filler loadings. The tensile strength and modulus of the biocomposites fabricated using the twin-screw extruding system were improved as compared with those fabricated using the single-screw extruding system, due to the improved dispersion of the fillers in the composite. There was no difference in the Izod impact strength of the composites fabricated using the twin-screw and single-screw extruding systems, the similar impact strength of both samples with different extruding processes might be due to the fact that impact test is not discriminating enough to reveal the difference in dispersion status of the present composites. The SEM micrographs revealed well-dispersed fillers on the fracture surfaces of the test samples fabricated using a twin-screw extruding system. (C) 2006 Elsevier Ltd. All rights reserved.