Chemical recycling of polyester textile wastes using silver-doped zinc oxide nanoparticles: an economical solution for circular economy

The waste management of polyethylene terephthalate (PET)-derived polyester (PES) textile is a global issue, and material recovery through chemical recycling can restore a circular economy. In our investigation, microwave-induced catalytic aminolysis and glycolysis of PES textile wastes using Ag-doped ZnO nanoparticles have been proposed. Ag-doped ZnO is prepared by the sol-gel method and characterised by XRD, FT-IR, UV-Vis, SEM-EDX and TEM. The reaction parameters such as PET-to-catalyst ratio, microwave power and irradiation time, temperature and catalyst recycling have been optimised. The catalyst was found to be more stable and could be recycled up to six times without losing its activity. Both the aminolysis and glycolysis of PES showed 100% conversion and afforded of bis (2-hydroxy ethylene) terephthalamide (BHETA) and bis (2-hydroxy ethylene) terephthalate (BHET), respectively. The depolymerisation of PES wastes using Ag-doped ZnO afforded BHETA and BHET for about 95 and 90%, respectively. The monomers BHET and BHETA confirmed by FT-IR, H-1 NMR and mass spectroscopy. According to the findings, 2 mol% Ag-doped ZnO has higher catalytic activity.