Tailoring carbanion structures for controlled anionic polymerization of acrylonitrile

Sivaram, S.; Dhal, Pradeep K.; Kashikar, S. P.; Khisti, R. S.; Shinde, B. M.; Baskaran, Durairaj

doi:10.1021/ma00007a040

Cited by 26 publications

(15 citation statements)

References 2 publications

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“…The types of initiators which can be used in metal-free anionic polymerization were supplemented by Sivaram et al [13][14][15][16]. Their resonance-stabilized carbanions, derived from 2-methyl-1,3-oxazoline, 2-benzyl-1,3-oxazoline, diethyl 2-phenylmalonate, and 2-benzyl-1,2-dihydro-1-isoquinoline carbonitrile, with tetrabutylammonium counter-cations, are said to tolerate a-hydrogens.…”

Section: Support For This Interpretationmentioning

confidence: 99%

Metal-free anionic polymerization of methyl methacrylate

Fieberg

Broska

Heibel

et al. 1998

Designed Monomers and Polymers

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Abstract�Results on the metal-free anionic polymerization of methyl methacrylate (MMA) are presented. MMA was polymerized in tetrahydrofuran, using tetrabutylammonium diethyl 2-ethylmalonate and tetrabutylammonium 2-nitropropanate as initiators. Immediate polymerization was observed only in cases where the initators did not contain traces of their precursor molecules, the presence of which causes an appreciable inhibition period. This is attributed to the transfer reaction between active species and the precursor molecules. Only after their consumption can the major polymerization start. Using very pure initiators, no inhibition period was observed. Curves from dilatometric measurements showed the existence of an induction period. As usual, this is attributed to an initiation reaction which is slower than the propagation reaction. It is more clearly marked for tetrabutylammonium diethyl 2-ethylmalonate than for tetrabutylammonium 2-nitropropanate as initiator. All polymerizations of MMA usually go to complete consumption of the monomer. However, termination reactions have to be taken into account as well. The well-known intramolecular cyclization reaction was not observed in the MMA system. Here, a Hofmann elimination reaction terminates the growing of chains, which is due to the butyl ligands of the ammonium cation, where a β-hydrogen atom can be transferred to the growing chain under the formation of tri-n-butylamine and 1-butene. To eliminate this termination step, tetramethylammonium diethyl 2-ethylmalonate was synthesized and used as the initiator for the polymerization of MMA. Now transalkylation under the formation of a methyl group terminated the saturated chain end and trimethyl amine could be detected as a second termination reaction. Neither of the termination reactions seems to be very fast. The molecular weight distributions of the synthesized polymers are relatively broad.

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Section: Support For This Interpretationmentioning

confidence: 99%

Metal-free anionic polymerization of methyl methacrylate

Fieberg

Broska

Heibel

et al. 1998

Designed Monomers and Polymers

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“…[8][9] In view of these difficulties, a range of alternative initiating systems has been investigated with the overall aim of increasing the livingness of the polymerization and reducing the complexity of the reaction setup. Major contributions include tailoring of the aggregation equilibria by application of coordinating additives (both of the counter ion and the enolate), 10 the development of group-transfer polymerization 11 and the use of metal-free counter ions, [12][13][14][15] as well as discrete organometallic porphyrin- [16][17] or metallocenebased [18][19][20] catalysts. More recently, Lewis pairs have been described by Lu, 21 Chen and Cavallo [22][23] as well as Rieger, 24 which enable very controlled polymerizations at room temperature, relying on the strong activating power of aluminium compounds such as Al(C 6 F 5 ) 3 or AlPh 3 .…”

Section: Introductionmentioning

confidence: 99%

N-Heterocyclic olefins as initiators for the polymerization of (meth)acrylic monomers: a combined experimental and theoretical approach

et al. 2017

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“…To get a high molecular weight polymer in any step growth polymerization, two requirements are the absence of side reactions and quantitative conversion to product. These factors necessitated exploration of the synthesis of model bis(Reissert compound) 14 by reacting isoquinoline with adipoyl chloride under various reaction conditions (Scheme IV). Popp et al have reported the synthesis of bis(Reissert compound) 14 in 8-10% yield by a two-phase method.17-20 We employed trimethylsilyl cyanide (TMSCN) as the cyanide ion source in a single-phase (dry methylene chloride) method21-22 and obtained 14 in 71% yield (entry 2, Table I), but when a catalytic amount of aluminum chloride was present, we obtained a quantitative yield (entry 3, Table I).…”

Section: Resultsmentioning

confidence: 99%

Poly(isoquinoline Reissert compounds): chemically reactive polyamides. 4

Jois¹,

Gibson²

1993

Macromolecules

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Reissert compounds, 2-benzoyl-l,2-dihydroisoquinaldonitrile (3) and 2,2'-adipoylbis[l,2dihydroisoquinaldonitrile] (14), have been prepared utilizing jVJV-dimethylformamide as solvent in quantitative yields. Lithium cyanide as a cyanide source in Reissert compound 3 synthesis is reported for the first time.Synthesis and characterization of novel, reactive poly(isoquinoline Reissert compound)s 17a-d are reported. Chemical modification of these polyamides via formation of the Reissert anion was demonstrated by methylation of the polyanion derived from 17b.

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Tailoring carbanion structures for controlled anionic polymerization of acrylonitrile

Cited by 26 publications

References 2 publications

Metal-free anionic polymerization of methyl methacrylate

Metal-free anionic polymerization of methyl methacrylate

N-Heterocyclic olefins as initiators for the polymerization of (meth)acrylic monomers: a combined experimental and theoretical approach

Poly(isoquinoline Reissert compounds): chemically reactive polyamides. 4

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