Chemical recycling of poly(ethylene terephthalate). application to the synthesis of multiblock copolyesters

Abstract

The chemical recycling of the poly(ethylene terephthalate), (PET), has been successfully carried out by glycoly-sis in the presence of bis (2-hydroxyethyl) terephthalate (BHET) resulting in the formation of hydroxytelechelic oligomers. These oligomers were then treated with carboxytelechelic poly(!-caprolactone) oligomers of Mn = 2300 and Mn = 730 g·mol-1 molecular weight, in the absence or presence of the titanium tetrabutyloxide (Ti(OBu)4) as a catalyst to get multiblock copolyesters. The chemical structure of the synthesized copolyesters was investigated by size exclusion chro-matography (SEC) and proton Nuclear Magnetic Resonance (1H NMR) spectroscopy. Moreover the differential scanning calorimetry (DSC) was used to explore their thermal properties. The ester-ester interchange reaction was observed between the two oligopolyesters, was studied and discussed in detail. © BME-PT.