Monomer-activated Copolymerization of Ethylene Oxide and Epichlorohydrin: In Situ Kinetics Evidences Tapered Block Copolymer Formation

作     者：Ann-Kathrin Danner Daniel Leibig Lea-Marie Vogt Holger Frey 

作者机构：Institute of Organic Chemistry Johannes Gutenberg- Universitat Mainz Duesbergweg 10-14 55128 Mainz Germany Graduate School Materials Science in Mainz Staudinger Weg 9 55128 Mainz Germany 

出 版 物：《Chinese Journal of Polymer Science》 (高分子科学（英文版）)

年 卷 期：2019年第37卷第9期

页      面：912-918页

核心收录：

学科分类：07[理学] 0817[工学-化学工程与技术] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 

基　　金：the Excellence Initiative by the Graduate School Materials Science in Mainz (GSC 266) 

主　　题：Epichlorohydrin Polymerization Ring-opening Copolymerization Reactivity ratios Epoxide 

摘      要：The monomer-activated anionic ring-opening copolymerization (AROP) of ethylene oxide (EO) and epichlorohydrin (ECH) using tetraoctylammonium bromide as an initiator and triisobutylaluminum (i-Bu3Al) as an activator was studied. The properties of the copolymers as well as the microstructure have been analyzed in detail via an in situ NMR kinetics study. The statistical copolymers exhibited molecular weights ranging from 2350 g·mol^-1 to 38000 g·mol^-1 (measured by SEC, PEG-standards) and moderate dispersities of 1.27-1.44. The thermal property tests revealed both a glass transition and melting for all copolymers, supporting a block-like nature. Applying in situ NMR kinetic measurements, the reactivity ratios of EO and ECH were determined to be strongly disparate, i.e., rEo = 9.2 and rECH = 0.10. This shows that the simple one-pot statistical anionic copolymerization of EO and ECH via the monomer-activated AROP resulted in the formation of strongly tapered, block-like structures. Furthermore, post-polymerization functionalization of the reactive chloromethyl groups by nucleophilic displacement was investigated for the copolymers. Copolymerization of EO and ECH offers a broad platform for further functionalization and therefore the possibility to prepare a variety of multifunctional PEGs.