Hydrothermal method-assisted synthesis of self-crosslinked all-lignin-based hydrogels

• Published in: International journal of biological macromolecules 2022-09, Vol.216, p.670-675
• Main Authors: Lv, Zilu, Zheng, Yong, Zhou, Hao, Pan, Zheng, Li, Chenyu, Dai, Lin, Zhang, Meng, Si, Chuanling
• Format: Article
• Language: English
• Subjects: Hydrogel; Hydrothermal method; Lignin
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2022.07.003

Lignin, as the most abundant aromatic biopolymer, is being widely studied to replace phenol and some other petroleum-based materials in the polymer industry. However, the low substitution of lignin and high levels of additives greatly limited the applications of lignin-based materials. Herein, we first propose a simple but effective hydrothermal method assisted synthesis for the fabrication of self-crosslinked lignin-based hydrogels (Lig-Scgel) with super-high-contents (75 wt%) of lignin and controllable mechanical properties. The self-crosslink mechanism was inspired by the repolymerization of lignins under a hydrothermal environment. The employment of self-condensation of lignin subunits in the synthesis of Lig-Scgel can significantly improve the degree of crosslinking, thereby greatly reducing the addition of toxic crosslinkers. The appearances, microstructures, crosslink densities, and mechanical properties of Lig-Scgels can be well controlled by simply altering the hydrothermal temperatures. This strategy not only promotes green and large-scale applications of lignin but also provides insights in the development of environment-friendly polymeric materials. •The hydrothermal method was used to synthesized self-crosslinking hydrogel.•The self-crosslink mechanism was inspired by the repolymerization of lignins.•Lig-Scgel has super-high-content of lignin and low-content of organic crosslinker.•The mechanical properties of Lig-Scgel can be tuned by hydrothermal temperatures.