3D printing with high content of lignin enabled by introducing polyurethane

• Published in: International journal of biological macromolecules 2022-11, Vol.221, p.1209-1217
• Main Authors: Zhou, Xinyuan, Ren, Zechun, Sun, Hao, Bi, Hongjie, Gu, Tongfei, Xu, Min
• Format: Article
• Language: English
• Subjects: 3D printing; Biocomposite; Mechanical properties; Rheological properties
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2022.09.076

The efficient utilization of lignin in 3D printing had attracted increasing attention using this abundant and eco-friendly material. However, the large-scale utilization of lignin in 3D printing remains a great challenge due to its inherent brittleness and non-thermoplasticity. In this study, thermoplastic polyurethane (TPU) was introduced to regulate the rheological properties of lignin for 3D printing. The Lignin/TPU composite of 3D printing exhibited a smooth surface, non-plastic, warm wood touch, and natural color at 50 wt% lignin loading. To further improve the mechanical properties of the composite, carbon fiber (CF) was added to the Lignin/TPU composite. The resulting CF/Lignin/TPU composites possessed 1.7 times higher tensile strength and 2.4 times higher elongation at break compared to Lignin/TPU composite. Meanwhile, the smooth surface of filament and dense interlayer bonds of printed specimens are also achieved. This work provides new insights to realize the high-value utilization of lignin and expands the practical application of lignin in 3D printing. [Display omitted] •TPU imparts lignin flexibility and thermoplastic properties.•Up to 50 wt% lignin composites available for 3D printing•The addition of carbon fiber enhances the mechanical properties of the composite.•Excellent interlayer bonding properties of 3D printed specimens after CF addition