Poly(butylene adipate-co-terephthalate) (PBAT) is one of the major commercialized biodegradable polymers. But modification of PBAT is still necessary to satisfy requirements of various applications. In this study, PBAT-based sulfonated copolyesters (PBATsI) with various compositions (7–12 mol% sulfonated unit) were synthesized by copolycondenation using dimethyl isophthalate-5-sulfonate sodium (SIPM) as a functional comonomer. The copolyesters were characterized with ¹H NMR, viscometer, DSC and XRD, and evaluated with TGA, tensile, gas barrier, contact angle and water dispersion testing. For the first time, it was found that the sulfonated copolyesters manifest improved color, clearly higher O₂ and CO₂ barrier properties, better hydrophilicity and excellent water dispersibility when compared with PBAT. The copolyesters containing 9–12 mol% BsI unit can be facilely dispersed in water to obtain stable dispersions with unimodal particle size distribution in < 100 nm range. These advantages may help them to find uses in tuning biodegradation rate of PBAT and further physical modification of PBAT.

聚（己二酸丁二酯-对苯二甲酸对苯二甲酸酯）（PBAT）是主要的商业化可生物降解聚合物之一。但是，仍然需要对PBAT进行修改以满足各种应用的需求。在这项研究中，使用间苯二甲酸二甲酯-5-磺酸钠（SIPM）作为功能性共聚单体，通过共缩聚反应合成了具有各种组成（7-12 mol％磺化单元）的基于PBAT的磺化共聚酯（PBATsI）。共聚酯用¹ H NMR，粘度计，DSC和XRD表征，并通过TGA，拉伸，阻气，接触角和水分散测试进行评估。首次发现磺化共聚酯具有改善的颜色，明显更高的O ₂和CO ₂与PBAT相比，具有阻隔性，更好的亲水性和出色的水分散性。可以轻松地将包含9-12 mol％BsI单元的共聚酯分散在水中，以获得单峰粒度分布在<100 nm范围内的稳定分散体。这些优点可以帮助他们找到在调整PBAT的生物降解率和进一步物理修饰PBAT中的用途。