Low-temperature dyeing performance of polylactic acid fabrics pretreated with natural deep eutectic solvent

Abstract

With growing concern over the environmental effects of petroleum-based plastics, significant strides have been made in developing bio-based materials. Polylactic acid (PLA) is a biodegradable material made from renewable starch. It has garnered considerable attention for its outstanding performance and ability to biodegrade in plastic products. However, the utilization of PLA fibers in fabrics has been restricted because of their challenges in dyeing and vulnerability to hydrolysis when exposed to high temperatures. In this study, we propose utilizing a natural and environmentally friendly deep eutectic solvent (NaDES) to modify PLA fibers, which results in outstanding dyeability at low temperatures. This modification technique offers the potential for sustainable textile processing. Under identical dyeing time conditions to C.I. Disperse Orange 30, NaDES-treated PLA exhibits comparable coloring performance to untreated PLA at 90 °C when dyed at 70 °C. Compared to conventional PLA dyeing, treating PLA with NaDES reduces the crystalline diffraction intensity of the fibers. This leads to a surface that is rougher and a looser structure. This leads to darker colors because the dye diffuses more easily into the fibers. Energy consumption and life cycle assessment results indicate that this process not only achieves a greater color depth of the PLA fabric but also reduces energy consumption by about 25.5%. The methodology proposed in this study presents a viable strategy for establishing a sustainable and circular economy with low carbon emissions, utilizing clean and alternative technologies.