Comparative investigation of treated bagasse and rice straw on physical and mechanical properties of natural fiber reinforced composites (NFRC)

This study investigated the effects of lignocellulosic materials (bagasse and rice straw) and four pulping processes as fiber’s treatment on physical and mechanical properties of natural fiber reinforced composites. lignocellulosic material in form of pulp flour (alkaline sulfite anthraquinone, soda anthraquinone, monoethanolamine, and chemical–mechanical pulping), 5 wt.% maleic anhydride polyethylene as coupling agent and High-density polyethylene (HDPE) were used to produce bio-composites by injection molding process. Polymer-to-fibers ratio for all reinforced composites was 60:40 wt.%. Mechanical properties including tensile properties, flexural properties, notched Izod impact strength and physical properties such as water absorption and thickness swelling were evaluated according to ASTM standards. The results showed that treated fibers compared to untreated fibers led to increase and decrease of flexural modulus in bagasse and rice straw reinforced composites, respectively. On the other hand, these treatments increased tensile modulus of both bagasse and rice straw reinforced composites. The results indicated that flexural and tensile strength of bagasse composites were significantly higher than rice straw composite. In contrast, rice straw composites showed higher impact strength, water absorption (WA), and thickness swelling (TS) in comparison with bagasse reinforced composites. The four pulping processes decreased WA and TS of both lignocellulosic composites.