Lacking available eco-friendly aliphatic-aromatic copolyesters with balanced mechanical properties, gas barrier properties and biodegradability is a foremost challenge in the field of degradable materials. 2,5-thiophenedicarboxylic acid (2,5-TDCA) as a new aromatic monomer with five-membered aromatic-ring can be synthesized from the renewable glucaric or muconic acid. In this work, a series of poly(butylene succinate-co-butylene 2,5-thiophenedicarboxylate) (PBSTh) copolyesters with TDCA units ranging from 10 to 80 mol% were synthesized by melt polycondensation. The results of ¹H-NMR, ¹³C-NMR and GPC revealed that the obtained random copolyesters possessed high number-average molecular weight from 54,800 to 88,600 g/mol. The copolymerized TDCA units was beneficial to improve the thermal stability, and T_d,5% in N₂ rose from 324°C of poly(butylene succinate) (PBS) to 344∼371°C of PBSThs. The mechanical properties of PBSThs were good with tensile modulus >29 MPa, tensile strength >11.4 MPa and elongation at break >523%, respectively. PBSThs showed better gas barrier properties than the well-known poly(butylene adipate-co-butylene terephthalate) (PBAT) and the BIFps of CO₂ and O₂ were 5.1∼60.2 times and 5.1∼32.0 times to PBAT, respectively. Also, the excellent biodegradability was proved both in enzymatic and compost environments and PBSThs have higher degradation rates than PBAT when the content of TDCA unit is lower than 60 mol%. In conclusion, the investigation of PBSThs has shown that the incorporation of 2,5-TDCA is effective in enhancing the overall properties of PBS and PBSTh can be a promising candidate in the field of biodegradable polymers.

缺乏具有平衡机械性能、气体阻隔性能和生物降解性的环保型脂肪族-芳香族共聚酯是可降解材料领域的首要挑战。2,5-噻吩二甲酸（2,5-TDCA）作为一种具有五元芳环的新型芳香族单体，可由可再生的葡糖二酸或粘康酸合成。在这项工作中，通过熔融缩聚合成了一系列 TDCA 单元为 10 至 80 mol% 的聚（丁二酸丁二醇酯-共聚 2,5-噻吩二甲酸丁二醇酯）（PBSTh）共聚酯。¹ H-NMR的结果， ¹³C-NMR 和 GPC 表明，所得无规共聚酯具有 54,800 至 88,600 g/mol 的高数均分子量。共聚的TDCA单元有利于提高热稳定性，N _{2中的T d,5%}从聚丁二酸丁二醇酯（PBS）的324℃上升到PBSThs的344～371℃。PBSThs的力学性能良好，拉伸模量>29 MPa，拉伸强度>11.4 MPa，断裂伸长率>523%。PBSThs表现出比众所周知的聚（己二酸丁二醇酯-共聚对苯二甲酸丁二醇酯）（PBAT）和CO ₂和O _{2的BIFps更好的阻气性能}分别是 PBAT 的 5.1～60.2 倍和 5.1～32.0 倍。此外，在酶促和堆肥环境中均证明了优异的生物降解性，并且当TDCA单元的含量低于60 mol％时，PBSThs比PBAT具有更高的降解率。总之，对 PBSThs 的研究表明，2,5-TDCA 的掺入可有效提高 PBS 的整体性能，并且 PBSTh 可以成为可生物降解聚合物领域的有希望的候选者。