In this study, the homopolymerization of 2,2‐dimethyltrimethylene carbonate (DTC) and its copolymerizations with ε‐caprolactone (CL) were carried out in detail using the isothiourea‐based Lewis pairs comprised 2,3,6,7‐tetrahydro‐5H‐thiazolo(3,2‐a)pyrimidine and magnesium halides (MgX₂) with benzyl alcohol (BnOH) as the initiator. The copolymerization of DTC and CL via one‐pot addition produced randomly sequenced copolymers. On the other hand, a well‐defined linear poly(ε‐caprolactone)–block–poly(2,2‐dimethyltrimethylene carbonate) (PCL‐b‐PDTC) diblock copolymer was prepared by simple sequential ring‐opening polymerization of CL and DTC. In addition, poly(ω‐pentadecalactone)–block–PDTC diblock copolymer was successfully prepared by the same strategy. Moreover, PDTC–poly(ethylene glycol) (PEG)–PDTC triblock copolymer was synthesized in the presence of PEG 2000. The effects of different polymerization conditions on the polymerization reactions have been systematically discussed. The resulting polymers were characterized by the ¹H and ¹³C NMR spectra, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐ToF MS). The block copolyester structures were confirmed by the ¹³C NMR spectroscopy and DSC characterizations. These results indicated that the supposed mechanism was a dual catalytic mechanism. The proposed mechanism involved activation of the monomer via coordination to the MgX₂, and the initiator alcohol was deprotonated by base. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2349–2355

中文翻译：

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基于异硫脲的路易斯对，用于碳酸2,2-二甲基三亚甲基酯与ε-己内酯和ω-十五烯内酯的均聚和共聚

在这项研究中，使用由2,3,6,7-四氢-5组成的基于异硫脲的Lewis对，详细进行了2,2-二甲基碳酸三亚甲基酯（DTC）的均聚及其与ε-己内酯（CL）的共聚。H-噻唑啉（3,2-a）嘧啶和卤化镁（MgX ₂），以苄醇（BnOH）为引发剂。DTC和CL通过一锅加成进行共聚产生了无序排列的共聚物。在另一方面，明确定义的线性聚（ε -己内酯） -嵌段-聚（2,2-二甲基亚丙基碳酸酯）（PCL- b -PDTC）二嵌段共聚物的制备是通过CL和DTC的简单的顺序开环聚合。另外，聚（ω-十五碳内酯）–嵌段-PDTC二嵌段共聚物是通过相同的策略成功制备的。此外，在PEG 2000存在下合成了PDTC-聚乙二醇（PEG）-PDTC三嵌段共聚物。系统地讨论了不同聚合条件对聚合反应的影响。所得聚合物的特征在于¹ H和¹³ C NMR光谱，凝胶渗透色谱（GPC），差示扫描量热法（DSC）和基质辅助激光解吸/电离飞行时间质谱（MALDI-ToF MS） 。嵌段共聚酯的结构得到了^13个的证实C NMR光谱和DSC表征。这些结果表明，推测的机理是双重催化机理。所提出的机制涉及通过与MgX ₂配位来活化单体，并且引发剂醇被碱去质子化。分级为4 +©2019 Wiley Periodicals，Inc.J.Polym。科学，A部分：Polym。化学 2019，57，2349–2355