Tensile Properties of Mechanically-Defibrated Cellulose Nanofiber-Reinforced Polylactic Acid Matrix Composites Fabricated by Fused Deposition Modeling; [熔融沉积法制备纤维素纳米纤维增强聚乳酸基复合材料的拉伸性能]

Biodegradable polymers are highly attractive as potential alternatives to petroleum-based polymers in an attempt to achieve carbon neutrality whilst maintaining the mechanical properties of the structures. Among these polymers, polylactic acid (PLA) is particularly promising due to its good mechanical properties, biocompatibility and thermoplasticity. In this work, we aim to enhance the mechanical properties of PLA using mechanically-defibrated cellulose nanofibers (CNFs) that exhibit remarkable mechanical properties and biodegradability. We also employ fused deposition modeling (FDM), one of the three-dimensional printing methods for thermoplastic polymers, for the low-cost fabrication of the products. Mechanically-defibrated CNF-reinforced PLA matrix composites are fabricated by FDM. Their tensile properties are investigated in two printing directions (0°/90° and +45°/-45°). The discussion about the relationship between printing direction and tensile behavoir of mechanically-defibrated CNF-reinforced PLA matrix composite is the unique point of this study. We further discuss the microstructure and fracture surface of mechanically-defibrated CNF-reinforced PLA matrix composite by scanning electron microscope. © 2021, Editorial Department of Transactions of NUAA. All right reserved.