Nanocellulose is a promising candidate for fabricating high-performance cellulosic materials due to its extremely fine structure and excellent mechanical properties. However, converting the extraordinary properties of individual nanofibers to macroscopic fibers through large-scale preparation remains a challenge. Inspired by the staple spun yarns, herein, we demonstrate a facile and scalable strategy for continuously additive fabrication of nanocellulose yarns by twisting stacked short nanocellulose slivers. Benefiting from the wet-stretching and twisting process, the resultant yarns with tightly intertwined cellulose nanofibers (CNFs) exhibit outstanding toughness (42.9MJ m -3 ) and fracture strain (20 %), respectively. Importantly, this approach can be extended to develop functional yarns such as fluorescent yarns, magnetic yarns, and conductive yarns. This work provides a new method for large-scale preparation of tough nanocellulose yarns for future functional materials, such as smart textiles and wearable electronics.
The current widespread use of plastics is a significant source of environmental pollution and increases the carbon load in the atmosphere, which has precipitated an urgent drive to replace plastics with biomass-based materials. In this paper, we prepared a lignocellulose-based, high-strength, water-resistant composite based on eucalyptus waste sawdust combined with a polyurethane prepolymer. The preparation process included pretreating sawdust with deep eutectic solvents (DESs) to remove some of the lignin and hemicellulose. A prepolymer preparation involving isocyanate groups using the prepolymerization of polyethylene glycol (PEG) with hexamethylene diisocyanate (HDI) grafted the prepolymers to the hydroxyl of the pretreated wood fibers, which were subsequently blended with acetylated pretreated sawdust to create the composite. The composite contained 67% wood fibers, possessed good tensile strength, and exhibited Young’s moduli of 18 MPa and 484 MPa. It was water-resistant with a contact angle of 92° and had a low water absorption of 32%, and it maintained a wet tensile strength of 5.71 MPa. The composite offers several advantages, including UV protection and thermal stability. This high-performance wood waste composite provides an alternative green production option for producing plastic materials.
危险品化学品经营许可证（带存储）