Evaluation of Poly(ethylene-terephthalate) Products of Chemical Recycling by Differential Scanning Calorimetry

摘要

Poly (ethylene-terephthalate), (PET) bottles waste was chemically recycled by glycolysis and hydrolysis. The depolymerization processes were carried out in different time intervals from 5 to 360 min, in two different molar ratios of PET/EG, 1:5 and 1:18 and at different temperatures. The PET glycolysis leads to formation of bis(2-hydroxy-ethyl)terephthalate (BHET) monomer and PET oligomers with hydroxyl and carboxyl end groups while PET hydrolysis is followed by formation of monomers terephthalic acid (TPA) and ethylene glycol (EG). Fractions of monomers and oligomers were further characterized by FTIR spectroscopy and by differential scanning calorimetry (DSC). The results show that DSC is successful method to describe the different structures of oligomers formed during chemical recycling of PET.