Biobased copolyesters: Synthesis, sequence distribution, crystal structure, thermal and mechanical properties of poly(butylene sebacate-co-butylene furandicarboxylate)

Fully biobased poly(butylene sebacate-co-butylene furandicarboxylate) (PBSFs) copolyesters were synthesized using a two-step melt polycondensation method from 2,5-furandicarboxylic acid (FDCA), sebacic acid(SA), and 1,4-butanediol (BDO). The composition, molecular weight, crystal structure, and thermal properties of PBSFs were investigated by 1H NMR, GPC, WAXD, DSC and TGA, respectively. Tensile properties were also evaluated. The number average molecular weight (Mn) ranges from 35600 to 46200 g/mol. PBSFs are all random copolyesters and exhibit excellent thermal stability. The glass transition temperature (Tg) and melting point temperature (Tm) of PBSFs gradually decreased with the increasing of butylene sebacate (BS) unit content (ФBS). Compared with poly(butylene furandicarboxylate) (PBF), PBSFs exhibit lower Tg and crystallinity. Thus, the ductility of PBF is substantially improved (the elongation at break (εb) of PBSFs ranges from 100 to 780%).