Synthesis and characterization of poly(isosorbide-co-butylene 2,5-furandicarboxylate) copolyesters

Fully biobased copolyesters poly(isosorbide-co-butylene 2,5-furandicarboxylate) (PISBF) were synthesized from 2,5-dimethylfuran dicarboxylate (DMFD), isosorbide (IS) and 1,4-butanediol (BDO) via transesterification and polycondensation reactions. The resulting copolymers were characterized by 1H NMR, 13C NMR, GPC, intrinsic viscosity, DSC, TGA and tensile testing, respectively. The NMR characterizations had confirmed that BDO was successfully introduced into the poly(isosorbide 2,5-furandicarboxylate) (PIF) polyester chains. Over the IS experimental composition range 20–80 % in copolymer chains, PISBF copolymers had TD, 5% values higher than 370 °C and TDM higher than 405 °C, and Tg values within the range of 55 °C and 150 °C. Introduction of BDO units into PIF chains imparted the PISBF copolyester with better mechanical performance than PIF, thus PISBF copolyesters with IS content of 20–50% were strong and toughened copolymers with Young's modulus about 1400 MPa, tensile strength at break higher than 53 MPa, and elongation at break higher than 46%.