Synthesis, thermal and mechanical properties of fully biobased poly(butylene-co-propylene 2,5-furandicarboxylate) copolyesters with low contents of propylene 2,5-furandicarboxylate units

To modify the physical properties and promote the practical application of biobased poly(butylene 2,5-furandicarboxylate) (PBF), fully biobased poly(butylene-co-propylene 2,5-furandicarboxylate) (PBPF) copolyesters with low contents (6 and 10 mol%) of propylene 2,5-furandicarboxylate (PF) units were synthesized from 2,5-dimethylfuran dicarboxylate, 1,4-butanediol and 1,3-propanediol via a transesterification and polycondensation reaction. The compositions, intrinsic viscosities, thermal stability, basic thermal parameters, crystal structures, and tensile mechanical properties of PBF and PBPF copolyesters were investigated in detail and compared with each other. Compared with those of PBF, PBPF copolyesters not only displayed high thermal decomposition temperatures (about 370 °C), slightly increased glass transition temperatures (about 40 °C), and still relatively high melting points (above 150 °C) but also exhibited the same crystal structures. The incorporation of a small amount of PF units significantly improved the tensile mechanical properties of PBPF copolyesters. [Display omitted] •Fully biobased PBPF copolyesters with low contents of PF units were synthesized.•PBPF displayed high Td, slightly increased Tg, and relatively high Tm (above 150 °C).•A small amount of PF units significantly improved the mechanical properties of PBPF.