Institute of Organic Chemistry, Johannes Gutenberg-University Mainz , Duesbergweg 10-14, D-55128 Mainz, Germany.
Graduate School Materials Science in Mainz , Staudingerweg 9, D-55128 Mainz, Germany.
Chem Rev. 2016 Feb 24;116(4):2170-243. doi: 10.1021/acs.chemrev.5b00441. Epub 2015 Dec 29.
The review summarizes current trends and developments in the polymerization of alkylene oxides in the last two decades since 1995, with a particular focus on the most important epoxide monomers ethylene oxide (EO), propylene oxide (PO), and butylene oxide (BO). Classical synthetic pathways, i.e., anionic polymerization, coordination polymerization, and cationic polymerization of epoxides (oxiranes), are briefly reviewed. The main focus of the review lies on more recent and in some cases metal-free methods for epoxide polymerization, i.e., the activated monomer strategy, the use of organocatalysts, such as N-heterocyclic carbenes (NHCs) and N-heterocyclic olefins (NHOs) as well as phosphazene bases. In addition, the commercially relevant double-metal cyanide (DMC) catalyst systems are discussed. Besides the synthetic progress, new types of multifunctional linear PEG (mf-PEG) and PPO structures accessible by copolymerization of EO or PO with functional epoxide comonomers are presented as well as complex branched, hyperbranched, and dendrimer like polyethers. Amphiphilic block copolymers based on PEO and PPO (Poloxamers and Pluronics) and advances in the area of PEGylation as the most important bioconjugation strategy are also summarized. With the ever growing toolbox for epoxide polymerization, a "polyether universe" may be envisaged that in its structural diversity parallels the immense variety of structural options available for polymers based on vinyl monomers with a purely carbon-based backbone.
本文综述了自 1995 年以来过去二十年中环氧烷烃聚合反应的最新趋势和进展，重点关注最重要的环氧化物单体——环氧乙烷（EO）、环氧丙烷（PO）和丁基氧化物（BO）。简要回顾了环氧烷烃（环氧化合物）的经典合成途径，如阴离子聚合、配位聚合和阳离子聚合。本文的主要重点是最近的、在某些情况下无金属的环氧化物聚合方法，如活性单体策略、使用有机催化剂，如氮杂环卡宾（NHCs）和氮杂环烯烃（NHOs）以及磷杂环戊二烯基碱。此外，还讨论了商业相关的双金属氰化物（DMC）催化剂体系。除了合成进展，还介绍了通过 EO 或 PO 与功能性环氧化物共聚单体共聚得到的新型多功能线性 PEG（mf-PEG）和 PPO 结构，以及复杂的支化、超支化和树枝状聚醚。还总结了基于 PEO 和 PPO 的两亲性嵌段共聚物（泊洛沙姆和 Pluronics）以及聚乙二醇化作为最重要的生物偶联策略的进展。随着环氧化物聚合的工具不断增加，可以设想一个“聚醚宇宙”，它在结构多样性上与基于纯碳主链的乙烯基单体聚合物的结构多样性相媲美。
