Three guanidinium zinc complexes (C1–C3) with distinct backbones and coordination modes were synthesized and utilized as catalysts for ring-opening polymerization (ROP) testing of racemic lactide (rac-LA) under industrially relevant conditions. In the presence of excess epoxide, even with monomer/catalyst ratios as high as 10⁴, the monomers were successfully polymerized at 150 °C or even 180 °C, resulting in linear polymers with molecular weights ranging from 8.2 kg mol⁻¹ to 28.5 kg mol⁻¹. The results of the experimentation, computation, and mass spectrometry analysis confirmed that the purposefully designed C3 has the greatest polymerization activity and is capable of producing PLA with a molecular weight of approximately 20.0 kg mol⁻¹ even in the presence of transesterification. Additionally, the catalytic system also facilitated copolymerization between various cyclic esters, yielding well-defined random copolymers. This research introduces innovative concepts for producing environmentally friendly catalytic systems that exhibit versatile application potential.

中文翻译：

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一种高活性锌基催化剂系统，用于在工业相关条件下进行丙交酯均聚和共聚反应


合成了三种具有不同主链和配位模式的胍锌配合物 （C1-C3），并用作在工业相关条件下对外消旋丙交酯 （rac-LA） 进行开环聚合 （ROP） 测试的催化剂。在过量环氧化物存在的情况下，即使单体/催化剂比高达 10：⁴，单体也可以在 150 °C 甚至 180 °C 下成功聚合，从而产生分子量范围为 8.2 kg ^mol-1 至 28.5 kg ^mol-1 的线性聚合物。实验、计算和质谱分析的结果证实，专门设计的 C3 具有最大的聚合活性，即使在酯交换作用下也能产生分子量约为 20.0 kg ^mol-1 的 PLA。此外，该催化体系还促进了各种环状酯之间的共聚，产生了定义明确的无规共聚物。本研究介绍了生产具有广泛应用潜力的环保催化系统的创新概念。