Bio‐Based High Toughness and Gas Barrier Properties Copolyesters Synthesized From Furandicarboxylic Acid

ABSTRACT

The transition from fossil feedstocks to bio‐based alternatives with tunable properties is a crucial step towards establishing a sustainable materials industry. In this study, a series of high molecular weight bio‐based poly (pentamethylene‐ co ‐ethylene glycol 2,5‐furandicarboxylate) (PPEF) copolyesters were successfully synthesized by the conventional melt polycondensation method from 2,5‐furandicarboxylic acid and 1,5‐pentanediol (PeDO) derived from biomass resource. The intrinsic viscosities [ η ] of PPEF copolyesters ranged from 0.70 to 0.84 dL/g with the number‐average molecular weights ( M _n ) ranging from 30,200 to 36,300 g/mol. The thermal stability, mechanical properties, and optical clarity of PPEF copolyesters were significantly improved with the increase in 1,5‐pentanediol content. Among them, the elongation at break of PPEF‐36 was as high as 182%, while maintaining a tensile modulus of up to 2350 MPa and a tensile strength of 75 MPa. In addition, PPEF copolyester demonstrated excellent gas barrier properties, with carbon dioxide and oxygen barrier improvement factors (BIFp) of 5.7–8.1 times and 3.1–5.5 times, respectively, compared with polyethylene terephthalate (PET). Therefore, bio‐based PPEF copolyesters with high toughness and excellent gas barrier properties will demonstrate significant application potential in food and medical packaging as well as specialized industrial sectors.