Extracting value from spent yerba mate residue: Lignocellulose-reinforced poly-l-lactic acid composites for fused deposition modeling

Abstract

Developing sustainable, biodegradable materials for 3D printing is vital to addressing global environmental challenges and reducing dependency on fossil-based resources. This study introduces novel filaments for fused deposition modeling (FDM) by incorporating yerba mate powder (YMP), an agro-industrial waste, into a poly-L-lactic acid (PLLA) matrix. By upcycling post-consumer yerba mate waste, a rich lignocellulosic material, this research demonstrates a practical approach to material circularity. Composite mixtures with specific YMP ratios were extruded into filaments, tested for their mechanical, thermal, and morphological properties, and evaluated for their compostability. A formulation with 2.5 wt% YMP, 1 wt% polyethylene glycol (PEG), and 2 wt%rheological modifier (RM) showed superior tensile strength, increasing this property by ~35 % in the printed specimens. Compostability tests revealed a weight loss of over 25 % in home compost conditions, demonstrating the potential of PLLA-YMP composites as a sustainable 3D printing alternative with improved biodegradation rates compared to standard PLLA. These findings underline the importance of integrating waste valorization and material sustainability in the additive manufacturing industry.