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( 1)H NMR, C-13 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 T-D,( 5%) values higher than 370 degrees C and T-DM higher than 405 degrees C, and Tg values within the range of 55 degrees C and 150 degrees 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%.