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.
This work was supported by the Program for Creation of Interdisciplinary Research and Ensemble Program of Frontier Research Institute for Interdisciplinary Sciences, Tohoku University.
Clc Number:
R318
图1 3D-printed specimens using the fused deposition modeling in the 0°/90° and +45°/-45° directionsFig.1
图2 Dimension of tensile specimens (JIS K 7161 1BA [14])Fig.2
图3 Relationship between specimen shape and stage temperatureFig.3
图4 Printed PLA-CNF 0.5% (volume fraction) tensile specimen in the 0°/90° directionFig.4
图5 CNF agglomeration in PLA-CNF 0.1% (volume fraction) tensile specimenFig.5
图6 Typical stress-strain curves of PLA-CNF composites printed at 0°/90° and +45°/-45°Fig.6
图7 CNF volume fraction versus ultimate tensile strength and fracture elongation of PLA-CNF composites printed in 0°/90° and +45°/-45°Fig.7
图8 Mechanical behavior of PLA-CNF composites printed a 0°/90° and +45°/-45° under tensile loadFig.8
图9 SEM fractographs of PLA-CNF 0.1 % (volume fraction) composite printed in the 0°/90° direction.Fig.9
图10 CNF agglomeration on fracture surface of PLA-CNF 0.3 % (volume fraction) composite printed in the 0°/90° direction.Fig.10