In Situ Kinetics Reveal the Influence of Solvents and Monomer Structure on the Anionic Ring‐Opening Copolymerization of Epoxides. Issue 1 (1st September 2022)

• Record Type: Journal Article
• Authors: Dreier, Philip; Matthes, Rebecca; Barent, Ramona D.; Schüttner, Sandra; Müller, Axel H. E.; Frey, Holger
• Other Names: Lederer Albena guestEditor.; Mutlu Hatice guestEditor.
• Is Part Of: Macromolecular chemistry and physics. Volume 224:Issue 1(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-09-01
• Subjects: anionic ring‐opening polymerization -- copolymerization -- epoxide monomers -- in situ kinetics -- polyethers; Polymers -- Periodicals; Polymerization -- Periodicals; Synthetic products -- Periodicals; Macromolecules -- Periodicals; 547.7
• DOI: 10.1002/macp.202200209
• Languages: English
• ISSNs: 1022-1352

Abstract

Abstract: In‐depth understanding of copolymerization kinetics and the resulting polymer microstructure is crucial for the design of materials with well‐defined properties. Further, insights regarding the impact of solvents on copolymerization kinetics allows for precisely tuned materials. In this regard, in situ 1 H NMR spectroscopy enables precise monitoring of the living anionic ring‐opening copolymerization (AROP) of ethylene oxide (EO) with the glycidyl ethers allyl glycidyl ether (AGE) and ethoxy vinyl glycidyl ether (EVGE), respectively. Determination of reactivity ratios reveals slightly higher reactivity of both glycidyl ethers compared to EO, emphasizing a pronounced counterion chelation effect by glycidyl ethers in AROP. Implementation of density functional theory (DFT) calculations further illustrates the complexation capability of ether‐containing side groups in glycidyl ethers, in analogy to crown ethers ("crown ether effect"). Investigation of the copolymerization in i) THF‐ d 8 and ii) DMSO‐ d 6 shows an increasing disparity of reactivity ratios for both glycidyl ethers compared to EO, clearly related to decreasing solvent polarity. Abstract : In situ monitoring of copolymerizations is a key tool for the investigation and validation of the resulting copolymer microstructure, providing detailed information up to full monomer conversion. The role of i) solvent polarity and ii) the comonomer structure on the copolymerization of ethylene oxide with two different glycidyl ethers is investigated via in situ 1 H NMR spectroscopy.