Tough and Strong All-Biomass Plastics from Agricultural and Forest Wastes via Constructing an Aggregate of Hydrogen-Bonding Networks

The development of all-biomass materials to replace conventional plastics has been gradually becoming a focus. However, all-biomass plastics, especially those fabricated from agricultural and forestry wastes, have the obstacles of poor formability and/or low toughness. Herein, we demonstrated a facile, efficient, and easy-to-scale method to significantly improve the formability and toughness of biomass materials via constructing an aggregate of hydrogen-bonding networks, where the relatively weak hydrogen bonding could be sacrificed during stretching. After a continuous preparation process that combined a paper-making process with an in situ welding process, the regenerated cellulose material with a layered microstructure was spontaneously formed. The interlayer hydrogen-bonding interactions could dissipate energy during stretching. As a result, the cellulose plastics were tough and strong. The tensile strength, strain, and toughness reached 154.9 MPa, 57.7%, and 81.76 MJ/m3, respectively, which were markedly higher than those of previous cellulose-based materials. The corresponding cellulose hydrogel exhibited an excellent strength of 9.5 MPa and a high strain of 171.4% also. During this scalable process, a 1-ethyl-3-methylimidazolium acetate (EmimAc) aqueous solution worked as a dispersant and a solvent, and a high solid content of cellulose/EmimAc (20 wt %) was used. Based on such an effective method, various agricultural and forestry wastes, including corn straw, wheat straw, grass, and wood powder, could be directly processed into high-tough all-biomass films, indicating a huge potential in ecofriendly materials, environmental protection, and bioresource utilization.