AI Summary & Key Takeaways
AI InsightThe results showed that compared to untreated bagasse and rice straw/HDPE composite, the addition of bagasse and rice straw pulp fibers increased significantly the mechanical properties such as tensile strength and modulus, flexural strength and modulus, and hardness.
📌 3 Key Takeaways
Abstract
Natural fibres are renewable, biodegradable, low-cost, low-density raw materials with high stiffness and strength compared to the other conventional products such as glass, aramid and carbon. There are a large variety of natural fibers such as rice straw, rice husk, wheat straw, corn stalks, palm, bagasse, hemp, flax and other agricultural residues. Natural fibers contain various organic materials (mainly celluloses as well as hemicelluloses and lignin) and there are several chemical treatments such as bleaching, esterification, silane treatment, use of compatibilizer, acetylation, alkali treatment and treatment with other chemicals in order to enhance the fiber matrix adhesion, which improve the physical and mechanical properties of composites. This study investigates different pulping processes as a novel chemical treatment on bagasse and rice straw fibers and consequently, properties of biocomposites. By pulping processes, the treated natural fibers as a biofiller could be used to produce the new classes of bio composites defined as pulp- plastic composites (PPCs). Different pulping processes which are categorized in mechanical, semi-chemical and chemical methods led to natural fibers with different anatomical and chemical properties such as surface modification and delignification in comparison with untreated fibers. Furthermore, the comparison of natural fibers treated by chemical and mechanical pulping processes and effects of these treatments on physical and mechanical properties of natural fibers are worth considering. Therefore in this paper, High-density polyethylene (HDPE), bagasse and rice straw fibers treated by four pulping processes (AS-AQ (alkaline sulfite anthraquinone), SODA-AQ (soda anthraquinone), MEA (monoethanolamine) and chemical mechanical pulping (CMP)) and maleic anhydride polyethylene as coupling agent were used to produce pulp plastic composites (PPCs) by injection molding. The physical and mechanical properties of corresponding composites were evaluated according to ASTM standards. The results showed that compared to untreated bagasse and rice straw/HDPE composite, the addition of bagasse and rice straw pulp fibers increased significantly the mechanical properties such as tensile strength and modulus, flexural strength and modulus, and hardness. The chemical pulps-reinforced composites showed better mechanical strengths than that of CMP-reinforced composites, but in some properties, CMP pulp composites have comparable results to the chemical pulp-reinforced composites. Natural fibers (untreated and treated) increased water absorption and thickness swelling of composites compared to pure HDPE. The comparison of PPCs from bagasse and rice straw untreated and treated fibers will be also presented and discussed.