Cellulose Acetate/Thermoplastic Polyurethane Porous Fibers: Fabrication and Thermal Insulation Optimization

Thermal insulation materials play a critical position in daily life and industrial processes, as they not only protect humans from cold environments but also reduce energy consumption and contribute to sustainable development. Biomass‐based porous fibers, featuring excellent thermal insulation properties and environmental sustainability, demonstrate substantial potential in the field of personal thermal management. In this work, a series of cellulose acetate (CA)/thermoplastic polyurethane (TPU) porous fibers were prepared via a combination of wet spinning and freeze‐drying techniques. The structure–property relationships among the preparation process, microstructure, and thermal insulation behavior were systematically investigated. Notably, at a CA/TPU mass ratio of 9/7 and a winding speed of 3.9 mm/s, the obtained porous fibers achieved a breaking stress of 2.84 MPa and a breaking strain of 7.41%. Such superior mechanical property not only ensures the stable continuous production of fibers during wet spinning, but also satisfy the tensile and weaving requirements of subsequent textile processing. Furthermore, the corresponding plain weave fabric exhibited optimal thermal insulation performance with a low thermal conductivity of 0.029 W/(m K). This work provides valuable guidance for the structural design and performance improvement of porous fibers, laying a solid foundation for their prospective applications in energy‐efficient textiles.