Sustainable Cross-Linking of Man-Made Cellulosic Fibers with Poly(carboxylic acids) for Fibrillation Control

Lyocell-type fibers often exhibit a high tendency to fibrillate under wet abrasion conditions, and fibrillation must be diminished for a better quality of the textile product. In this study, we propose a green route for cross-linking regenerated cellulose fibers using citric acid (CA) and 1,2,3,4-butanetetracarboxylic acid (BTCA) to prevent the fibers from fibrillation. We investigated the influence of process conditions and additives on the fibrillation tendency and fiber properties. The fibrillation tendency of the cross-linked fibers highly depended on the concentration of cross-linker solution, curing temperature, and curing time. BTCA showed better cross-linking performance in comparison to CA. CA cross-linked fibers also suffer from yellowing issues due to the formation of unsaturated side products during curing. Thus, glycerol and xylitol were added during cross-linking to avoid the reaction that led to the unsaturated compound. Washing fastness tests confirmed that the cross-linking has high stability when the cross-linker concentration is 100 g/L and fibers are cured at 180 °C for 5 min. The disadvantage of the CA and BTCA cross-linked fibers was a relatively low mechanical performance. The study demonstrated that adding softener in the cross-linker solution enhanced the mechanical properties and was also able to reduce the curing temperature without deteriorating the fibrillation index of the cross-linked fibers.