Grignard-based anionic ring-opening polymerization of propylene oxide activated by triisobutylaluminum

Better known as alkylating agents, Grignard reagents are investigated as deprotonating agents of an alcohol to generate magnesium alkoxides for the initiation and propagation of the anionic ring-opening polymerization of propylene oxide. By using an excess of triisobutylaluminum, this magnesium-aluminum system enables a full conversion polymerization in a few hours yielding controlled poly(propylene oxide) up to 10000 g/mol with relatively low dispersity. Characterizations by NMR and MALDI-ToF-mass spectrometry allowed the determination of the chain-ends and therefore the associated initiation mechanisms. This study revealed that propylene oxide can be polymerized in presence of a magnesium-based counter-ion. Concomitant initiations by alkoxide, halide and hydride are discussed. (C) 2015 Elsevier Ltd. All rights reserved.