Abstract: To explore the feasibility of waterless or low-water dyeing for bio-based fibers, this paper developed a non-aqueous medium dyeing system using decamethylcyclopentasiloxane for polylactic acid (PLA) fibers. The effects of dyeing temperature, time, dye concentration, and bath ratio on PLA’s dyeing performance were examined and compared with traditional water-bathed dyeing. Results showed that when the dye dosage is 2% (o.w.f.), the dyeing temperature is 140 °C, the holding time is 40 min, and the liquor ratio is 1:20, the non-aqueous dyeing system can achieve high-temperature dyeing of PLA. The properties of PLA fabrics dyed under this process are comparable to those dyed by traditional water bath dyeing, with superior colorfastness and minimal impact on fiber mechanical strength.

Key words: non-aqueous media; polylactic acid fabrics; D5; disperse dye; high-temperature dyeing