Polymerization of ethylene oxide by alkali metal-naphthalene complexes in tetrahydrofuran

Kazanskii, K. S.; Solov’yanov, A. A.; Èntelis, S.G.

doi:10.1016/0014-3057(71)90036-x

Cited by 88 publications

(21 citation statements)

References 10 publications

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“…[34][35][36][37][38][39] Furthermore, it has been found that complexation of the RO À M þ ion pair by the growing PEO chain results in an auto-acceleration during the early stage of EO polymerization (degree of polymerization DP < 4-6). [2,40] Consequently, complexation of the Li þ counterion by the PEO macroinitiator might result in an additional weakening of lithium alkoxide aggregates. The apparent rate constants of propagation are almost identical for the first and second batch of EO (k app ¼ 4.56 Â 10 À3 min À1 , k p ¼ 0.042 L Á mol À1 Á s À1 ).…”

Section: Resultsmentioning

confidence: 99%

“…[1][2][3][4][5][6] For lithium counterions, however, only initiation but no propagation has been observed under conventional reaction conditions. [7,8] This effect was attributed to the strong aggregation of lithium alkoxides resulting from the comparatively high charge density of the lithium cation.…”

Section: Introductionmentioning

confidence: 99%

“…[2] Lithium as counterion was activated by dimethyl sulfoxide (DMSO) for EO polymerization. [10,11] In addition, there is a report stating that polymerization of ethylene oxide with Li þ counterions is possible by adding tetramethylethylenediamine (TMEDA) as complexing agent for Li þ , but there are no further hints concerning this reaction.…”

Section: Introductionmentioning

confidence: 99%

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Anionic Polymerization of Ethylene Oxide in the Presence of the Phosphazene Base Bu^tP₄ – Kinetic Investigations Using In‐Situ FT‐NIR Spectroscopy and MALDI‐ToF MS

Schmalz

Lanzendörfer

Abetz

et al. 2003

Macro Chemistry & Physics

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Fourier‐transform near‐infrared (FT‐NIR) fiber‐optic spectroscopy was successfully used to monitor the anionic polymerization of ethylene oxide (EO). Kinetic data are provided for the polymerization of EO with the sec‐BuLi/ButP4 initiating system under different reaction conditions. In addition, the influence of different initiators and reaction conditions on the polymerization of EO is investigated. Online monitoring using NIR spectroscopy reveals an unexpected induction period present in EO homopolymerizations as well as in the synthesis of PEO containing block copolymers with [Li/ButP4]+ counterions. The resulting polymers are characterized by size exclusion chromatography (SEC). A low‐molecular‐weight polystyrene‐block‐poly(ethylene oxide) (PS‐b‐PEO) diblock copolymer was synthesized to gain more insight into the observed induction period by matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry (MALDI‐ToF MS) on samples taken during EO polymerization. The induction period is believed to be a result of different factors involved in the formation of active centers, for example, the break up of lithium alkoxide aggregates by the phosphazene base ButP4, and chain length effects. It depends on reaction temperature, concentration of the phosphazene base ButP4, as well as the structure of the initiator.SEC traces for EO homopolymerizations using different initiating systems at 50 °C.magnified imageSEC traces for EO homopolymerizations using different initiating systems at 50 °C.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Anionic Polymerization of Ethylene Oxide in the Presence of the Phosphazene Base Bu^tP₄ – Kinetic Investigations Using In‐Situ FT‐NIR Spectroscopy and MALDI‐ToF MS

Schmalz

Lanzendörfer

Abetz

et al. 2003

Macro Chemistry & Physics

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“…This phenomenon has been attributed to ions association. 20 In fact, in THF, potassium alkoxides are associated in the form of trimers. Addition of a protic compound destroys this three-dimensional network responsible of a high viscosity of the reaction medium.…”

Section: Syntheses Of Ps(peo) 3 Star Block Copolymers From Ps Macroinmentioning

confidence: 99%

Synthesis of PS(PEO)3 star block copolymers from a heterotetrafunctional initiator

Glaied

Delaite

Dumas

2007

J. Polym. Sci. A Polym. Chem.

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“…Lithium alcoholates are known to be inefficient for such polymerizations. Alcoholate reactivity increases in the order Na' < K+ < Cs+ 16,17).…”

Section: Introductionmentioning

confidence: 99%

Synthesis of poly(ethylene oxide) with a terminal amino group by anionic polymerization of ethylene oxide initiated by aminoalcoholates

Mosquet

Chevalier

Perchec

et al. 1997

Macro Chemistry & Physics

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Lafarge-CoppCe recherche, Laboratoire Central de Recherches, BP 15, SUMMARYPoly(ethy1ene oxide)s having a primary or secondary amino group at one chain end have been synthesized by direct anionic polymerization of ethylene oxide initiated by aminoalcoholates. The ring opening reaction of ethylene oxide by the amino group could be avoided when the alcoholate was reactive enough, that is, with potassium alcoholates in dry aprotic medium (THF). In this case, a living anionic polymerization of ethylene oxide occurred, with full conversion of the monomer. This is shown by the NMR and molecular weight characterizations of the polymers and kinetic studies of the polymerization.

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Polymerization of ethylene oxide by alkali metal-naphthalene complexes in tetrahydrofuran

Cited by 88 publications

References 10 publications

Anionic Polymerization of Ethylene Oxide in the Presence of the Phosphazene Base Bu^tP₄ – Kinetic Investigations Using In‐Situ FT‐NIR Spectroscopy and MALDI‐ToF MS

Anionic Polymerization of Ethylene Oxide in the Presence of the Phosphazene Base Bu^tP₄ – Kinetic Investigations Using In‐Situ FT‐NIR Spectroscopy and MALDI‐ToF MS

Synthesis of PS(PEO)3 star block copolymers from a heterotetrafunctional initiator

Synthesis of poly(ethylene oxide) with a terminal amino group by anionic polymerization of ethylene oxide initiated by aminoalcoholates

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Polymerization of ethylene oxide by alkali metal-naphthalene complexes in tetrahydrofuran

Cited by 88 publications

References 10 publications

Anionic Polymerization of Ethylene Oxide in the Presence of the Phosphazene Base ButP4 – Kinetic Investigations Using In‐Situ FT‐NIR Spectroscopy and MALDI‐ToF MS

Anionic Polymerization of Ethylene Oxide in the Presence of the Phosphazene Base ButP4 – Kinetic Investigations Using In‐Situ FT‐NIR Spectroscopy and MALDI‐ToF MS

Synthesis of PS(PEO)3 star block copolymers from a heterotetrafunctional initiator

Synthesis of poly(ethylene oxide) with a terminal amino group by anionic polymerization of ethylene oxide initiated by aminoalcoholates

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Anionic Polymerization of Ethylene Oxide in the Presence of the Phosphazene Base Bu^tP₄ – Kinetic Investigations Using In‐Situ FT‐NIR Spectroscopy and MALDI‐ToF MS

Anionic Polymerization of Ethylene Oxide in the Presence of the Phosphazene Base Bu^tP₄ – Kinetic Investigations Using In‐Situ FT‐NIR Spectroscopy and MALDI‐ToF MS