Organocatalytic Ring-Opening Copolymerization of Trimethylene Carbonate and Dithiolane Trimethylene Carbonate: Impact of Organocatalysts on Copolymerization Kinetics and Copolymer Microstructures
Organocatalytic Ring-Opening Copolymerization of Trimethylene Carbonate and Dithiolane Trimethylene Carbonate: Impact of Organocatalysts on Copolymerization Kinetics and Copolymer Microstructures
复制标题
三亚甲基碳酸酯和二硫杂环戊烷三亚甲基碳酸酯的有机催化开环共聚：有机催化剂对共聚动力学和共聚物微观结构的影响
DOI：
10.1021/acs.biomac.8b00415
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发表时间：
2018
影响因子：
6.2
通讯作者：
Meng Fenghua
中科院分区：
文献类型：
--
作者：
Wei Jingjing;Meng Hao;Guo Beibei;Zhong Zhiyuan;Meng Fenghua
采用酸性和碱性有机催化剂，即，磷酸二苯酯（DPP）和三氮杂双环[4.4.0]癸-5-烯（TBD）的反应。有趣的是，DPP和TBD引起完全不同的聚合动力学和共聚物序列。以甲氧基聚乙二醇（mPEG-OH）为引发剂，DPP为催化剂，TMC和DTC的共聚反应按一级反应进行，两种单体均在72 h内接近聚合完成，得到了分子量可预测、分散性低（Mw/Mn= 1.09-1.19）、序列无规的共聚物。相比之下，TBD在类似条件下使TMC和DTC的共聚速度快得多（2-4 h内实现高单体转化率），得到具有受控摩尔质量和中等分散度（Mw/Mn= 1.27-1.80）的共聚物。此外，聚合动力学研究表明，DTC优先聚合，其次是TMC的一级聚合，导致嵌段共聚物。这些结果表明，有机催化剂的类型有一个关键的环状碳酸酯的聚合动力学，共聚物序列，和摩尔质量控制的影响。
The ring opening copolymerization of trimethylene carbonate (TMC) and dithiolane trimethylene carbonate (DTC) using acidic and basic organocatalysts, i.e., diphenyl phosphate (DPP) and triazabicyclo[4.4.0]dec-5-ene (TBD), was systemically investigated. Interestingly, DPP and TBD gave rise to completely different polymerization kinetics and copolymer sequences. The copolymerization of TMC and DTC using methoxy poly(ethylene glycol) (mPEG–OH) as an initiator and DPP as a catalyst proceeded in a first-order manner and to near completion in 72 h for both monomers, yielding well-controlled copolymers with random sequences, predictable molar mass, and low dispersity (Mw/Mn= 1.09–1.19). By contrast, TBD brought about much faster copolymerization of TMC and DTC under similar conditions (high monomer conversion achieved in 2–4 h), to furnish copolymers with controlled molar mass and moderate dispersity (Mw/Mn= 1.27–1.80). Moreover, polymerization kinetics revealed that DTC was preferentially polymerized followed by first-order polymerization of TMC, leading to blocky copolymers. These results signify that type of organocatalysts has a critical influence on polymerization kinetics of cyclic carbonates, copolymer sequence, and molar mass control.