A Circular Manufacturing Platform for High‐Performance Cellulosic Fibers via Hydrogen‐Bond Unzipping and Rezipping

This study outlines a closed‐loop manufacturing process for cellulosic fibers designed to meet the textile industry's urgent demand for eco‐friendly, cost‐effective solvents, circular‐design principles, and superior material performance. The process utilizes a deep eutectic solvent composed of calcium chloride, formic acid, and water, which effectively facilitates cellulose dissolution and partial esterification. Followed by dry‐jet wet spinning and ethanol‐induced coagulation, the initially disordered cellulose chains are reorganized into an ordered, compact fibrillar structure. The resulting fibers showcase a relative crystallinity of 63.9%, tensile strength of 222 MPa, elongation exceeding 20%, and thermal stability above 180°C. Furthermore, they possess textile‐relevant properties including thermal conductivity of 0.064 W·m −1 ·K −1 , moisture regain of 12.4%, and luster comparable to cuprammonium rayon. Significantly, the process allows for the concurrent recovery of both the solvent and coagulant, maintains fiber reusability, and minimizes waste and costs. The life‐cycle assessment indicates that this approach significantly reduces the carbon footprint and resource depletion compared to conventional rayon production. These findings establish a cost‐effective, eco‐friendly alternative to current solvent systems, addressing both environmental and industrial needs.