Rapid fiber-to-fiber recycling of poly (ethylene terephthalate) and its dye from waste textiles without damaging their chemical structures

Recycling waste poly(ethylene terephthalate) (PET) textiles faces significant obstacles due to lack of cost-effective and non-destructive technologies to purify PET. Unsuccessful purification led to processing and property problems. PET recycling via depolymerization-repolymerization is economically unviable and environmentally irresponsible. Here we demonstrate a cost-effective and clean fiber-to-fiber recycling technology, converting afterlife apparels into pure and colorless PET followed by fiber spinning and dyeing of the recycled PET fibers with recycled disperse dyes, for the time-efficient and cost-effective PET recycling. The disruption of dye-polymer interactions in PET driven by controlled swelling using environmentally benign solvents ensures a complete dye separation from PET fabrics within less than 30 min. PET with 100% property retention and disperse dyes with the same intact structure and dyeability are recovered via our technology. Given that our recycling obtained pure PET from waste textiles, the fiber-to-fiber recycling potentially has lower material and energy costs than conventional PET production.