Macro and micromechanical preliminary assessment of the tensile strength of particulate rapeseed sawdust reinforced polypropylene copolymer biocomposites for its use as building material

The growing environmental awareness promotes the research of greener and more sustainable materials for their use in building materials. Polyolefin-based wood plastic composites (WPCs) have attracted the attention of researchers in the last decades mainly due to their improved mechanical properties, low weight and low cost. On the other hand, rapeseed is one of the most extended harvests in the world and their production is expected to increase in the next years, according to FAO (Food and Agriculture Organization). Rapeseed is mainly used for the production of biodiesel, and moving from an oil-based economy to a bio-based economy will presumably involve increases of rapeseed production. Its harvest produces high amount of agroforestry residue in the shape of integral stems which can be exploited as polymer reinforcing element, although very little information is found in the literature in this respect. In this work, the viability of rapeseed sawdust reinforced polypropylene copolymer composites was analysed regarding its mechanical tensile strength. Besides, the coupling agent percentage to ensure the best performance was also studied. The tensile strength of the produced composites has been modelled using well-known micromechanical models which allow the determination of the fibre and matrix contributions to the composite strength. The results showed that competitive green composite materials can be obtained using a byproduct of rapeseed harvesting.