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

Authors received financial support of the Spanish Ministry of Science, Innovation, and Universities to the project CICEP (ref. TED2021-131039B-C31) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) from Argentina. Open Access funding provided thanks to the CRUE-CSIC agreement with Elsevier

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