A Simplified Approach for the Metal-free Polymerization of Propylene Oxide

Overview

Journal RSC Adv

Publisher Royal Society of Chemistry

Specialty Chemistry

Date 2022 May 6

PMID 35519681

Authors

Charlotte Vogler

Stefan Naumann

Affiliations

Soon will be listed here.

Abstract

Triethyl borane (EtB), in combination with phosphazene-type superbases, has recently emerged as a powerful co-catalyst for the anionic polymerization of epoxides. Here, it is demonstrated that the monomer-activating property of EtB can also compensate for the application of much gentler organobases. This not only results in simpler setups, but also significantly reduces nucleophilicity/basicity-derived side reactions. Notably, this principle applies to such a degree that simple 4-dimethylaminopyridine (DMAP) or 1,4-diazabicyclo[2.2.2]octane (DABCO) can serve to polymerize propylene oxide (PO). With suitable initiators, this results for example in very well-defined block copolyethers ( ≤ 1.03) without requiring work-up to remove side products such as PPO homopolymer. Performance correlates nicely with the corresponding organobase proton affinities (PAs), and a limiting PA of 220-230 kcal mol was identified for successful PO polymerization.

Citing Articles

Synthesis of Poly(propylene oxide)-Poly(-dimethylacrylamide) Diblock Copolymer Nanoparticles via Reverse Sequence Polymerization-Induced Self-Assembly in Aqueous Solution.

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PMID: 38222027 PMC: 10782481. DOI: 10.1021/acs.macromol.3c01939.

Chiral diboranes as catalysts for the stereoselective organopolymerization of epoxides.

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