Aminolytic Depolymerisation of Polyethylene Terephthalate Wastes using Sn doped ZnO Nanoparticles

Abstract Poly(ethylene terephthalate) (PET) is one of the most consumed polymers because of its excellent thermal and mechanical properties. By increasing in PET production and since the disposal of PET waste has growing to be a major global environmental issue each year. Chemical recycling is a most successful method to achieve circular economy in the PET utilizing industries. Current research work aims to complete depolymerization of waste PET from soft drink bottles by the aminolysis method to produce bis (2-hydroxy ethylene) terephthalamide (BHETA) in the presence of Sn doped ZnO. To evaluate catalytic activity, pure and Sn2+ doped ZnO nanoparticles prepared using different Sn2+ molar ratios at 0.5, 1.0 and 2.0 mol% and calcined at 500 0C for 1h. The synthesized catalysts characterised using FT-IR, XRD, and UV-vis spectroscopy. The surface morphology and percentage doping obtained from SEM and SEM-EDS, respectively. We have observed a reduction in optical band gap and crystallite size of ZnO due to tin doping. Aminolytic depolymerization of PET waste using ethanolamine promoted by Sn doped ZnO effectively under conventional thermal method. Increase in the yield of the BHETA observed with respect to increasing doping percentage of Sn and 1-2 mol% Sn doped ZnO nanoparticles afforded over 90% of BHETA. Structure and purity of BHETA, depolymerised product characterized by FT-IR, 1HNMR, 13C NMR, and MS.