Microwave-Induced Chemical Recycling of Colored Polyester Textile Wastes Promoted by Zn[(L)Proline]₂, as a Recyclable Homogeneous Catalyst

Textile waste made of post-consumer 100% polyester (PES) made of polyethylene terephthalate (PET), is complicated and contains chemicals and colorants, thus recycling is not given priority. To produce monomers like bis(2-hydroxyethyl) terephthalate (BHET) and bis(2-hydroxyethyl) terephthalamide (BHETA) through chemical recycling, PES is depolymerised in this study. PES with characteristics akin to virgin materials is synthesized mostly from the recovered monomer products. We synthesized [Zn(L)-Proline]₂, an environmentally friendly Lewis acidic catalyst, and evaluated its catalytic performance in glycolysis and aminolysis to depolymerize PES textile waste of various colors. A thorough understanding of the molecular structure of the pure monomers BHET and BHETA was obtained using FT-IR, mass spectrometry, ¹H, and ¹³C-NMR techniques. Further, the mechanism underlying PES depolymerization was proposed. This work highlights the recovery of monomers from PES wastes employing an environmentally friendly catalyst to overcome the obstacles in recycling post-consumer polyester textile waste. It plays an important role in establishing sustainable practices in the PES based textile sector.