Closed-loop recycling of colored regenerated cellulose fibers from the dyed cotton textile waste

Worldwide, 45 million tons of waste cotton textiles are produced annually, of which 75% is burned and buried, leading to serious environmental pollution. In this study, a method for directly preparing colored regenerated cellulose fibers (CRCFs) from dyed cotton textile waste (DCTW) was demonstrated. The tensile strength of CRCFs reached 226 MPa, which was equivalent to that of commercial viscose fibers. CRCFs exhibited excellent color fastness and hydrophilicity. In addition, CRCFs can be reprocessed into secondary CRCFs. The tensile strength of secondary CRCFs was 14.64% less than that of the primary CRCFs due to the reduction in the polymerization degree of secondary CRCFs; however, it also can be woven into fabrics. The exploration of the secondary utilization of CRCFs provides an experimental basis for prolonging the service life of DCTW. This approach of preparing CRCFs achieves closed-loop recycling of waste colored cellulose textiles and prevents environmental pollution caused by decoloring and dyeing.