Enhancing polyester composites with nano Aristida hystrix fibers: Mechanical and microstructural insights

The utilization of natural fibers in polymer composites is increasingly popular due to their sustainability, cost-effectiveness, and favorable mechanical properties. This study introduces the novel use of Aristida hystrix fibers, processed for the first time into nano-sized particles via ball milling, to enhance dispersion and bonding within a polyester matrix. These nanoparticles were incorporated into polyester resin at various weight percentages (0 wt%, 1 wt%, 3 wt%, 5 wt%, 7 wt%, and 9 wt%), and composite laminates were fabricated using solvent casting and compression molding techniques. Mechanical properties were evaluated through tensile, flexural, and impact strength tests following ASTM standards. The composite containing 5 wt% nano fiber exhibited the optimum mechanical performance, with tensile strength of 30.13 MPa, flexural strength of 43.685 MPa, and impact strength of 1.87 kJ/m². At higher fiber loadings, particle agglomeration led to performance reduction. Water absorption studies indicated that increased nano fiber content resulted in higher moisture uptake, influencing long-term durability. Scanning Electron Microscopy (SEM) provided insights into fiber–matrix interfacial behavior, dispersion quality, and fracture mechanisms. Overall, this work establishes the first-time development of polyester composites reinforced with nano Aristida hystrix fibers, demonstrating their potential as a sustainable and high-performance material for lightweight structural applications in automotive, aerospace, and marine sectors.