Giant reed ( Arundo donax L.) enhanced polylactic acid composites: processing, characterization, and performance of injection moulded and water degraded samples

Abstract

This study explores the incorporation of renewable resources from Arundo donax into a polylactic acid matrix to enhance mechanical properties and sustainability. This approach uses lignocellulosic fillers from this fast-growing plant species to cut plastic waste and support a circular economy. Two types of fillers, stem fibres and shredded plant particles, were added to the PLA matrix, focusing on how they affect water interactions and material properties. Characterization tests, including rheology, TGA, DSC, WAXS, and DMTA, were conducted to assess the structure and performance of the composites. Results indicate that Arundo fillers minimally alters composite chemical structures, while rheological behaviour is significantly influenced by the filler type and loading. Thermal degradation varies slightly with filler content, ensuring stability for injection moulding. Mechanical performance is optimized with 10 % and 20 % filler content, enhancing stiffness and impact strength, while 40 % fibres leads to increased brittleness. The study highlights the impact of filler type on moisture absorption. Water saturation weakens tensile strength, but re-drying helps recover some properties, demonstrating PLA/Arundo composites’ resilience under moderate loads. This research emphasizes the complex interplay between filler characteristics, composite structure, and their effects on mechanical properties, crucial for evaluating the suitability of PLA composites in various applications.