Particle-reinforced polypropylene biocomposites based on lignocellulosic wastes

This study presents the production of polypropylene (PP) biocomposites utilizing different biomasses such as apricot kernel shell (AKS, 48% lignin), hazelnut shell (HS, 40%), walnut shell (WS, 35% lignin), and corn cob (CC, 15% lignin, 40% cellulose). The biocomposites were manufactured using a twin-screw extruder by varying the type and amount (5% to 20%) of biomass used as filler. The characterizations are done using spectral, thermal, and mechanical methods. In addition, using two different brands of PP samples the effects of crystallinity on thermal and mechanical properties of the biocomposites were examined. The composition of the biomass was important; higher lignin content (as in AKS) resulted in better compounding due to its hydrophobic behavior. Another important factor affecting the performance of the biocomposites was filler content. The optimum performance was obtained 10% content. In general, addition of the filler caused an increase in crystallinity which was detected by spectral and thermal methods.