Large-Scale Production of Continuous Sheath-Core Composite Phase Change Fibers for Personal Thermal Management in Cold Alpine Environments by Coaxial Wet Spinning Technology

In response to the need for personal thermal management in the sudden temperature changes in cold environments, a scalable sheath-core phase change composite fiber (PCF) has been successfully fabricated on a large scale through coaxial wet spinning. The PCF composition includes a protective polyurethane (PU) sheath and solid-liquid phase change materials (PCMs) with heat storage components. Encapsulation stability, encapsulation efficiency, thermal properties, morphology, mechanical properties, and fabric insulation properties have all been systematically studied. The results obtained from differential scanning calorimetry (DSC) indicate that PCFs exhibit obvious endothermic and exothermic enthalpies and possess similar melting and solidification temperature ranges that are comparable to PCMs. Based on the encapsulation stability and DSC experiments, it has been determined that PCF4 has the highest encapsulation efficiency among the encapsulation-stabilized fibers. PCF4 has an encapsulation efficiency of 77.77% and storage and exothermic enthalpies of 157.98 and 152.36 J/g, respectively. The PCF4 was tested and found to have an ultimate tensile of 4.08 +/- 0.26 MPa and an elongation at a break of 258.52 +/- 8.22%. A composite fabric woven with PCF4 and cotton yarn demonstrated an obvious temperature plateau and a heat release process during thermal insulation testing.