Development and characterization of mechanical,thermal,and rheological performance of PLA -sisal fiber composite filament for FDM printing application

Polylactic acid (PLA) has low thermal resistance and is brittle, which makes it hard to utilize in fused deposition modeling (FDM) applications that need biodegradable materials. To improve fiber-matrix adhesion, this study creates PLA composite filaments with 6 wt.% short sisal fibers (2–4 mm) that have been chemically treated with 5% sodium chloride (NaOH) and 2% benzoyl chloride (C₆H₅COCl). In addition, fused filaments are added with 2% polyethylene glycol (PEG) and maleic anhydride (MA) to enhanced strengthen and wettability. It revealed, treatments applied to the surface raised the point of thermal breakdown by 18.5% and reduced hydrophilic peaks by 30%–40% confirmed via FTIR. At 400°C, treated composites had a 12% higher melt flow index and a 10% lower mass loss, at which they broke down were 150°C–300°C higher. Biodegradation and water absorption tests verified the material’s reduced hydrophilicity; after 72 h, less than 6% of the material was absorbed. Tensile strength of untreated composites as 43 MPa showed of 10% fall in contrast to 48 MPa for neat PLA. C₆H₅COCl treated composites had a tensile strength of 68 MPa (42% higher than PLA), and NaOH-treated samples had a tensile strength of 82 MPa (70% higher) with 12% strain. The SEM results demonstrate that the composites have improved ductility and fiber-to-matrix bonding. Composites made of PLA filler of sisal exhibit superior mechanical properties and thermal stability; as a result, they are well-suited for usage in bio-based additive printing of environmental consumer items, structural components, and tableware’s.