Ecofriendly\nDyeing Strategy Based on Dyeing Kinetics\nand Thermodynamic Analysis for Melt-Spun Polyurethane Fibers

Melt-spun polyurethane fibers (MSPUFs) have garnered\npopularity\nowing to efficient production methods and exceptional stability. However,\nthe development of the MSPUF has been restricted by challenges such\nas poor dyeability as well as energy and cost concerns associated\nwith the dyeing process. Herein, we devised a highly efficient dyeing\ntechnique that operates at a lower temperature and a shorter duration.\nIn comparison to conventional dyeing methods, our novel approach reduces\nthe temperature from 98 to 75 °C, while reducing the amount of\ndye utilized by 25% and the dyeing time by 50%. In this method, the\nmodifier increases both the positive charge and the amorphous zone\nof the fiber, while rational dyeing conditions are designed based\non thermodynamic and kinetic analyses. This strategy enabled a 76.3%\nincrease in <i>E</i>% and a 45.9% increase in K/S values\nat reduced temperatures and a shorter time while simultaneously improving\nthe dye–fiber bonding fastness. This research methodology not\nonly enhances the dyeing performance of MSPUF but also reduces energy\nconsumption and dyeing costs, presenting an ecofriendly and economically\nnovel approach for the development of dyeable MSPUF.