Through a two-stage transesterification/esterification and polycondensation method, three biobased poly(hexamethylene 2,5-furandicarboxylate-co-adipate) (PHFA) copolyesters with low contents of hexamethylene adipate (HA) units were synthesized in this research. The thermal properties, crystal structure, and tensile properties of PHFA copolyesters and poly(hexamethylene 2,5-furandicarboxylate) (PHF) homopolymer were extensively studied and compared with each other. All PHFA copolyesters still maintained good thermal stability. The glass transition temperatures, melting point temperatures, and equilibrium melting point temperatures of PHFA copolyesters gradually decreased with the increase of HA units. PHFA copolyesters displayed the same crystal structures as PHF. The elongation at break remarkably increased to 498.3 ± 12.0% for the PHFA copolyester containing 30 mol% of HA units (PHFA30) from 197.3 ± 12.2% for PHF; moreover, PHFA30 still showed a relatively high melting point temperature of 116.4 °C, similar to that of biodegradable poly(butylene succinate) (about 114 °C).

通过两个阶段的酯交换反应/酯化和缩聚法，三个生物基聚（六亚甲基2,5- furandicarboxylate-共本研究合成了己二酸己二酸 (HA) 单元含量低的共聚多酯。对 PHFA 共聚酯和聚（六亚甲基 2,5-呋喃二甲酸酯）（PHF）均聚物的热性能、晶体结构和拉伸性能进行了广泛的研究并相互比较。所有 PHFA 共聚酯仍保持良好的热稳定性。随着HA单元的增加，PHFA共聚酯的玻璃化转变温度、熔点温度和平衡熔点温度逐渐降低。PHFA 共聚酯显示出与 PHF 相同的晶体结构。含有 30 mol% HA 单元 (PHFA30) 的 PHFA 共聚酯的断裂伸长率从 PHF 的 197.3 ± 12.2% 显着增加到 498.3 ± 12.0%；而且，