Synthesis of poly(ethylene terephthalate)-block-poly (tetramethylene oxide) copolymer by direct polyesterification of reactive oligomers

Abstract

The object of this study was the synthesis of thermoplastic elastomer compounds by direct copolyesterification of reactive oligomers of poly(ethylene terephthalate) (PET) and of poly(tetramethylene oxide) (PTMO). PET was glycolysed to synthesise hydroxytelechelic oligomers of PET. Commercially available hydroxytelechelic PTMO was modified to synthesise carboxytelechelic oligomers. The chemical structures of these oligomers were investigated by 1H NMR and size exclusion chromatography. Multiblock poly(ester-ether) was then obtained by polyesterification of the hydroxytelechelic and carboxytelechelic oligomers, using different catalysts and different reaction conditions. The best stoichiometric ratio was determined to lead to the highest M̄n. The chemical structure of the synthesised poly(ester-ether) was investigated by size exclusion chromatography and 1H NMR. The thermal and thermomechanical behaviour of the synthesised poly(ester-ether) was investigated by differential scanning calorimetry and by dynamic mechanical analysis, and showed a thermoplastic elastomer behaviour. This product could also be an interesting way of chemically recycling PET waste.