Use of cryptates in anionic polymerization. III. Alkali‐metal hydroxides and salts

Boileau, Sylvie; Hémery, Patrick; Kaempf, B.; Schué, François; Viguier, Michel

doi:10.1002/pol.1974.130120407

Cited by 23 publications

(9 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The purification of toluene and MMA as well as the experimental techniques are described elsewhere.17 Potassium salts of the alcohols were prepared by the reaction of potassium metal with an excess of alcohol in toluene followed by removing solvent and alcohol under vacuum at 100°C during at least 15 hours. This gave the alkoxides as snow-white powders.…”

Section: Methodsmentioning

confidence: 99%

Homogeneous Polymerization of Methyl Methacrylate Initiated by Potassium Salts of Methanol and t-Butyl Alcohol in the Presence of Cryptand [222]

Viguier

Collet

Schué

1982

Polym J

View full text Add to dashboard Cite

ABSTRACT:Homogeneous polymerization of methyl methacrylate initiated by potassium salts of methanol and t-butyl alcohol was studied in toluene in the presence of cryptand [222). The polymers prepared were predominantly syndiotactic. The isotacticities increased slightly with an increase in temperature. More than thirty years ago, it was claimed that alkali metal salts of primary alcohols could not initiate the polymerization of methyl methacrylate (MMA) in ether.' More recently, the oligomerization of MMA by CH 3 0-jCH 3 0H solutions has been studied.Z· 3 Oligomers having a degree of polymerization up to six were isolated and characterized. Initiation proceeded by the addition of CH 3 0-to the double bond, and termination by protonation from the methanol.t-Alkoxides, n-butoxides, derivatives of poly(ethylene oxide) of alkali metals as well as ethylmagnesium alkoxides for the initiation of the homogeneous polymerization of methacrylic acid esters have been described in previous papers. 4 -10 It has also been shown that the polymerization of MMA by alkali metal salts of 2-methoxyethanol and like compounds can be carried out in aprotic dipolar solvents such as hexamethylphosphoramide, dimethyl sulfoxide, and dimethylacetamide." Polymerization was greatly promoted by these solvents, even when in small quantities. It is also well known that cryptands such as (I) complex cationic species very strongly and hence promote nucleophilic reactionsY Several studies on the polymerization using such complexing agents have been reported. 13 _,In this paper, we report on the homogeneous polymerization of MMA in toluene by potassium salts of methanol and t-butyl alcohol in the presence of cryptand (1). It was accepted, according to our previous communication, 17 that such complexing agents increase the reactivity of the alkoxide. (Potassium methoxide and t-butoxide are noted respectively MeOK and t-BuOK.) EXPERIMENTAL MaterialsThe purification of toluene and MMA as well as the experimental techniques are described elsewhere.17 Potassium salts of the alcohols were prepared by the reaction of potassium metal with an excess of alcohol in toluene followed by removing solvent and alcohol under vacuum at 100°C during at least 15 hours. This gave the alkoxides as snow-137

show abstract

Section: Methodsmentioning

confidence: 99%

Homogeneous Polymerization of Methyl Methacrylate Initiated by Potassium Salts of Methanol and t-Butyl Alcohol in the Presence of Cryptand [222]

Viguier

Collet

Schué

1982

Polym J

View full text Add to dashboard Cite

show abstract

“…The 5 wt % decomposition temperatures were 328, 432, and 456 °C, respectively. The decomposition temperature is strongly dependent on the molecular weight of the polymers 51 and generally increases with an increase of the molecular weight. The P3HT(solvent free) had a branched structure with a smallest M n compared to the other materials (see GPC and 1 H NMR results), and the TGA results reflect the effect of M n on the decomposition temperature.…”

Section: Synthesis and Characterization Of P3htmentioning

confidence: 99%

Poly(3-hexylthiophene) Grains Synthesized by Solvent-Free Oxidative Coupling Polymerization and Their Use as Light-Responsive Liquid Marble Stabilizer

et al. 2019

View full text Add to dashboard Cite

Solvent-free oxidative coupling polymerization of 3-hexylthiophene using FeCl3 oxidant was conducted to synthesize poly(3-hexylthiophene) grains. Optical and scanning electron microscopy studies confirmed production of submillimeter-sized atypical grains with rough surfaces. Solubility test, Fourier transform infrared spectroscopy, and 1H nuclear magnetic resonance studies indicated the branching and cross-linking of the poly(3-hexylthiophene). Elemental microanalysis and X-ray photoelectron spectroscopy studies confirmed that the poly(3-hexylthiophene) grains were doped with chloride ions. The poly(3-hexylthiophene) grains showed hydrophobic character due to hexyl side chains, and the critical surface tension was determined to be 25.9 mN m–1. The poly(3-hexylthiophene) showed a light-to-heat photothermal property, and near-infrared laser irradiation to the poly(3-hexylthiophene) grains induced a rapid temperature increase up to 664 °C. The poly(3-hexylthiophene) grains can work as an effective liquid marble stabilizer with a photothermal property, and the liquid marble exhibited locomotion on a water surface due to near-infrared laser-induced Marangoni flow.

show abstract

“…7,28,29 The use of LiCl as an additive results in its interaction with living chain ends through formation of a µ-type The ion-pair association is known to be strongly influenced by the nature of cations. 32,33 The presence of organic and inorganic salts capable of interacting with the growing ion pair has a great influence on the course of anionic polymerization of alkyl (meth)acrylates. 34 This type of salt effect influencing the position of ionic dissociation equilibria of the anionic polymerization of alkyl (meth)acrylates mainly depends on the Lewis acidity and steric factor of the added salt.…”

Section: Introductionmentioning

confidence: 99%

“…The ion-pair association is known to be strongly influenced by the nature of cations. , The presence of organic and inorganic salts capable of interacting with the growing ion pair has a great influence on the course of anionic polymerization of alkyl (meth)acrylates .…”

Section: Introductionmentioning

confidence: 99%

Specific Salt Effect of Lithium Perchlorate in Living Anionic Polymerization of Methyl Methacrylate and tert-Butyl Acrylate

Baskaran

Sivaram

1997

Macromolecules

View full text Add to dashboard Cite

Living anionic polymerization of methyl methacrylate can be achieved at −40 °C in tetrahydrofuran (THF) and at −78 °C in toluene/THF (9/1 v/v) using (1,1-diphenylhexyl)lithium as the initiator in the presence of lithium perchlorate (LiClO4) as the additive. Polymerization of tert-butyl acrylate also proceeds in a living manner at −78 oC in THF. Polymers with narrow molecular weight distributions and high initiator efficiencies can be obtained. The use of lithium perchlorate retards the rate of polymerization. The ratio of LiClO4 to initiator has a greater influence in determining the control of polymerization. The beneficial effect of lithium perchlorate is attributed to its efficient interaction with growing ester−enolate ion pairs.

show abstract

Use of cryptates in anionic polymerization. III. Alkali‐metal hydroxides and salts

Cited by 23 publications

References 4 publications

Homogeneous Polymerization of Methyl Methacrylate Initiated by Potassium Salts of Methanol and t-Butyl Alcohol in the Presence of Cryptand [222]

Homogeneous Polymerization of Methyl Methacrylate Initiated by Potassium Salts of Methanol and t-Butyl Alcohol in the Presence of Cryptand [222]

Poly(3-hexylthiophene) Grains Synthesized by Solvent-Free Oxidative Coupling Polymerization and Their Use as Light-Responsive Liquid Marble Stabilizer

Specific Salt Effect of Lithium Perchlorate in Living Anionic Polymerization of Methyl Methacrylate and tert-Butyl Acrylate

Contact Info

Product

Resources

About