Polylactic Acid (PLA) Reinforced with Date Palm Sheath Fiber Bio-Composites: Evaluation of Fiber Density, Geometry, and Content on the Physical and Mechanical Properties

Significant interest for utilizing and processing natural fibers (NF) to develop sustainable and fully biodegradable composites evolved as the global environmental concerns upsurge. Date palm tree (DPT) accounts for more than 2.8 million tons of waste annually, making it the most abundant agricultural biomass waste in the MENA region. This study investigates the effect of date palm fiber (DPF) density, diameter size and content on both the mechanical and physical properties of polylactic acid (PLA) reinforced DPF bio-composite. The bio-composites are developed using melt-mixing technique which is followed by compression molding. The influence of the mechanical properties is investigated by evaluating the tensile, flexural and impact strengths. Meanwhile bio-composite thickness swelling (TS), moisture content (MC) and water absorption (WA) characteristics are evaluated. Bio-composite microstructures are examined using SEM to investigate the interfacial bonding between PLA matrix and DPF. Results showed that at 40 wt.% DPF, the TS, MC, and WA were the highest demonstrating an increase of 4.10%, 4.95%, and 8.22%, respectively. Although the results demonstrated a decrease in mechanical properties as DPF content increased (depending on DPF geometry), the results indicate that the developed technologies could be commercialized under the waste management scheme for non-structural applications.