The ring-opening polymerization (ROP) of cyclic esters using multifunctional initiators is an efficient methodology that allows the preparation of polyesters with well-defined architectures. Here a series of star-shaped poly(β-hydroxybutyrates) (PHBs) has been synthesized by ROP of β-butyrolactone (BBL) with an amido-oxazolinate zinc catalyst. The star-shaped structure is constructed via a core-first approach, in which several bio-based multifunctional alcohols serve as the initiator for ROP. Specifically, three-, four-, and multi-armed star polymers are obtained and characterized by various techniques including NMR, GPC, TGA, and DSC, and the incorporation of the core structure in the star-shaped PHBs has been confirmed. The thermal properties can be modified by changing the arm number and arm length of PHBs, and the thermal stability decreases as the number of arms increases when they have the same arm lengths. The wetting behavior determined from AFM studies demonstrates a minimum in the macroscopic contact angle as a function of the number of arms of a star-shaped PHB.

使用多功能引发剂的环酯开环聚合 (ROP) 是一种有效的方法，可以制备具有明确结构的聚酯。这里一系列星形聚（β羟基丁酸酯）（PHB的）的已通过的ROP合成β-丁内酯 (BBL) 和酰胺基恶唑啉酸锌催化剂。星形结构是通过核优先方法构建的，其中几种生物基多功能醇作为 ROP 的引发剂。具体而言，获得了三臂、四臂和多臂星形聚合物，并通过包括 NMR、GPC、TGA 和 DSC 在内的各种技术进行表征，并且已经证实了星形 PHB 中的核心结构的结合。通过改变PHBs的臂数和臂长可以改变热性能，当臂长相同时，热稳定性随着臂数的增加而降低。从 AFM 研究确定的润湿行为表明，作为星形 PHB 臂数量的函数，宏观接触角具有最小值。