Controlled anionic homo- and copolymerization of ethylene oxide and propylene oxide by monomer activation
CARLOTTI, Stéphane
Laboratoire de Chimie des polymères organiques [LCPO]
Team 1 LCPO : Polymerization Catalyses & Engineering
< Reduce
Laboratoire de Chimie des polymères organiques [LCPO]
Team 1 LCPO : Polymerization Catalyses & Engineering
Language
en
Article de revue
This item was published in
International Journal of Biological Macromolecules. 2007, vol. 40, n° 18, p. 6510-6514
Elsevier
English Abstract
The anionic polymerization of ethylene oxide initiated by alkali metal-based initiators suffers from low polymerization rates even in polar media. We found that the addition of triisobutylaluminum to initiators like alkali ...Read more >
The anionic polymerization of ethylene oxide initiated by alkali metal-based initiators suffers from low polymerization rates even in polar media. We found that the addition of triisobutylaluminum to initiators like alkali metal alkoxides or tetraalkylammonium salts strongly enhances the ethylene oxide polymerization rate, while keeping its living character. At ratio [i-Bu3Al]/[initiator] = 1.5, the controlled synthesis of poly(ethylene oxide) of relatively high molar masses is achieved in short time at room temperature in dichloromethane or toluene. Beside the formation of an aluminate 1:1 complex involving i-Bu3Al and the initiator, a second complex between the trialkylaluminum and the oxirane is formed, which strongly increases the reactivity of the epoxide monomer. Gradient di- and triblock ethylene oxide/propylene oxide copolymers of high molar mass are readily prepared with this system.Read less <
English Keywords
alkali metal initiator
additives
phase behavior
polymerization
poly(ethylene oxide)
block copolymers
reactivity ratios
aqueous solutions
trialkylaluminum monomer activation
Origin
Hal imported