High molecular weight linear poly(ethylene terephthalate-co-ethylene 2

5-furandicarboxylate) (PEFT) was synthesized via direct esterification method based on terephthalic acid

2

5-furandicarboxylic acid(FDCA) and ethylene glycol.Tetrabutyl titanate was used as catalyst.Magnetic resonance spectroscopy (1H-NMR and 13C-NMR) confirmed the expected PEFT structure.The results of X-ray diffraction (XRD) displayed that the PEFT copolyesters were amorphous at original ecology.The results of differential scanning calorimeter (DSC) showed that the PEFT copolyesters had a single glass-transition temperature Tg (73.3~84.2 ℃) and Tg increased continuously with the increase of PEF content.The Tgs of PEFT copolyesters were between that of PET and PEF.The results of thermo gravimetric analysis (TGA) indicated that PEFT copolyesters had excellent thermal stability

although it was slightly lower than that of PET.The PEFT copolyesters were thermally stable up to 390 ℃.The thermal properties of PEFT copolyester were between those of PET and PEF.The results of tensile tests showed that PEFT-10

PEFT-70 and PEFT-90 copolyesters had good mechanical properties compared with PET.The results showed that FDCA could partially replace terephthalic acid to synthesis polyester.