Temperature and concentration effects on polar‐modified alkyllithium polymerizations and copolymerizations

Antkowiak, Thomas A.; Oberster, A. E.; Halasa, Adel F.; Tate, D. P.

doi:10.1002/pol.1972.150100504

Cited by 152 publications

(73 citation statements)

References 8 publications

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“…This kinetic problem can be tackled by the addition of a polar compound, such as THF or diethyl ether 20) . This strategy has been studied again by 7 Li NMR spectroscopy at room temperature.…”

Section: Resultsmentioning

confidence: 99%

Anionic synthesis of [1,4-poly(diene)-b-syndiotactic poly(methyl methacrylate)] diblock copolymers:7Li NMR study of the intermediate reaction of lithium poly(diene) anion with 1,1-diphenylethylene

Zune

Dubois

Jérôme

et al. 1999

Macromol. Chem. Phys.

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SUMMARY:The end-capping with 1,1-diphenylethylene (DPE) of living 1,4-poly(diene) lithiated anions prepared in cyclohexane (Chx) and toluene is a major but poorly controlled step in the synthesis of syndiotactic poly(methyl methacrylate) (sPMMA) containing block copolymers. The kinetics of the reaction have been studied by means of 7 Li NMR not only in Chx and toluene but also in their mixtures with polar solvents, since the solvent polarity must be increased for MMA to be predominantly converted into sPMMA. Although the addition of a polar solvent (tetrahydrofuran (THF), diethyl ether) to Chx and toluene is known to increase the reactivity of living polymeric anions, contaminating lithium salts, such as lithium hydroxide, slow down the end-capping reaction even when 10 vol.-% polar solvent is added. Moreover, the polymeric diphenylalkyllithium anions are unstable in 1/9 (v/v) THF/Chx mixture, as a result of the nucleophilic attack of THF. On the basis of all these observations, new experimental conditions are proposed for improving the control of the anionic block copolymerization of 1,3-dienes and MMA to yield 1,4-poly(diene) and sPMMA containing block copolymers.

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Section: Resultsmentioning

confidence: 99%

Anionic synthesis of [1,4-poly(diene)-b-syndiotactic poly(methyl methacrylate)] diblock copolymers:7Li NMR study of the intermediate reaction of lithium poly(diene) anion with 1,1-diphenylethylene

Zune

Dubois

Jérôme

et al. 1999

Macromol. Chem. Phys.

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“…By adding polar compounds (modifiers) to the a1ky11ithium initiated SIB copo1ymerisation, the vinyl content in the butadieny1 fraction may be increased [7]. This provides an extra degree of freedom in varying the Tg and imparting certain properties to the polymer.…”

Section: Effect Of Modifiers On Sib Copolyherisation Kineticsmentioning

confidence: 98%

Polymer Design in the Anionic Polymerisation of Butadiene and Styrene

Graafland

Ballegooijen

1990

Integration of Fundamental Polymer Science and Technology—4

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As a result of the improved understanding of the relation between styrenejbutadiene copolymer architecture and the relevant tyre properties there is an increasing demand for tailor-made 'mu1tip1e-Tg' SBR copolymers. In this paper it is shown how the 'semi-steady-state batch process' in combination with a simple kinetic model of the SIB copo1ymerisation can be used to prepare various random SBR block copolymers in which the blocks may differ substantially in styrene and vinyl content.

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“…5 By selecting a polar environment for the copolymerization, the terminal double bond can be changed from a 1,4-configuration to a 1,2-or vinyl configuration. 6 Isoprene may also be used as the comonomer to add further variety to the chemical and configurational structure, and hence to the reactivity of the end-group. Living polyanions have distinctive absorptions in the UV-visible spectral range, leading to characteristic colours.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Fourier transform Raman spectroscopic study of diene-terminated polystyrene oligomers

Ward

Edwards

Johnson

2005

J. Raman Spectrosc.

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Polystyrene oligomers capped with a known number of butadiene or isoprene units were synthesized by 'living' anionic polymerization in cyclohexane. The FT-Raman spectra of these compounds show small but significant differences in n(C C) wavenumber position depending on whether just a single unit or several units of the diene are present at the chain end. However, if the butadiene experiments are repeated under polar-modified conditions, so that 1,2-rather than 1,4-addition takes place, the n(C C) Raman band position is found to be independent of the number of 'out-of-chain' vinyl double bonds which are present. This conclusion is explained in terms of the mass change on diene addition to the polymer chains. Application of the method for the quantitation of polymer chain-end diene termination is proposed.

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Temperature and concentration effects on polar‐modified alkyllithium polymerizations and copolymerizations

Cited by 152 publications

References 8 publications

Anionic synthesis of [1,4-poly(diene)-b-syndiotactic poly(methyl methacrylate)] diblock copolymers:7Li NMR study of the intermediate reaction of lithium poly(diene) anion with 1,1-diphenylethylene

Anionic synthesis of [1,4-poly(diene)-b-syndiotactic poly(methyl methacrylate)] diblock copolymers:7Li NMR study of the intermediate reaction of lithium poly(diene) anion with 1,1-diphenylethylene

Polymer Design in the Anionic Polymerisation of Butadiene and Styrene

Synthesis and Fourier transform Raman spectroscopic study of diene-terminated polystyrene oligomers

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