Sustainable Strategy\nfor Promoting the Color Strength\nand Dimensional Stability of Polylactic Acid Fabrics

In the realm of environmental protection and sustainable\ndevelopment,\npolylactic acid (PLA) materials have garnered significant attention\ndue to their biodegradability. Moreover, PLA is more widely used in\nthe clothing and home textile industries. However, the application\nof PLA in the textile industry is constrained by hydrolysis issues\nduring conventional aqueous dyeing processes. This paper investigates\na waterless dyeing technique utilizing linear silicone (LS) as a nonaqueous\ndyeing medium. Because PLA fibers are dyed in a nonaqueous environment,\nthe breaking strength of PLA fabrics in the LS waterless dyeing system\nincreased by 4% to 10%, and the breaking elongation improved by 7%\nto 20% at dyeing temperatures of 110 and 120 °C. However, it\nshowed a reduction of 23.4% at 120 °C in water-bathed dyeing.\nThe LS waterless dyeing system facilitates high-temperature dyeing\nof PLA fibers, ensuring that the fibers remain intact at temperatures\nbelow 140 °C. In contrast, when subjected to traditional water\nbath dyeing at 120 °C, the fibers exhibit significant breakage.\nThe hydrolysis concerns are mitigated in the LS waterless dyeing bath,\nresulting in enhanced thermal stability and mechanical properties\ncompared to that in fibers dyed in a conventional water-bathed dyeing\nsystem. At equivalent temperatures, the <i>K</i>/<i>S</i> value of dyed PLA fabric can be improved when a small\ndosage of acetic acid is employed in a waterless dyeing bath, while\ncolor fastness to washing, rubbing, and light remain uninfluenced.\nThe selected dyeing medium can be recycled and reused, which not only\nsignificantly improves the resource utilization efficiency of the\ndyeing process but also effectively reduces the generation and emission\nof waste. This study provides a promising approach for waterless dyeing\nof PLA fiber, facilitating their practical application and marking\nan important milestone toward sustainability in the textile industry.