Bio-based high gas barrier polyesters based on furandicarboxylic acid: Trade-off between ethylene and propylene diols

Abstract

A series of bio-based poly(ethylene-co-propylene furandicarboxylate) (PEPF) copolyesters with different compositions were synthesized from dimethyl-2,5-furandicarboxylate, ethylene glycol and 1,3-propanediol by transesterification and melting polycondensation. Their chemical structure, composition and sequence distribution were confirmed by 1H NMR and 13C NMR. The results of GPC showed that the obtained copolyesters had a high number average molecular weight between 25000 g/mol and 30900 g/mol. The thermal properties characterized by DSC showed that the Tg increased with the mole fraction of EF from 64.4℃ for PEPF-23 to 83.2℃ for PEPF-84 as well as the samples displayed a high Young's modulus between 2800 and 3360 MPa and tensile strength between 56 and 89 MPa. Furthermore, the PEPF copolyesters exhibited excellent CO2, O2 and H2O barrier properties compared with poly(ethylene terephthalate) with the BIFp of 8.7–10 times, 3.7–4.4 times and 1.5–1.6 times, respectively. The transparency of PEPFs was up to 89% by cutoff at 700 nm and had better solvent resistance. This work builds a bridge between poly(ethylene 2,5-furandicarboxylate) and poly(propylene 2,5-furandicarboxylate) and PEPFs owned excellent thermo-mechanical and gas barrier properties could be used in food packaging fields.