Complexes of stannic chloride and alkyl phenols and the influence of these complexes and of free phenol on the cationic polymerization of isobutene

Bauer, R. F.; LaFlair, Ronald T.; Russell, K. E.

doi:10.1139/v70-206

Cited by 13 publications

(15 citation statements)

References 2 publications

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“…Isobutene, ethyl chloride, and stannic chloride were purified by distillation on the vacuum line as described earlier (4). The solid phenols were recrystallized from methanol-water or ethanol-water mixtures and then sublimed at low pressure.…”

Section: Mnterinlsmentioning

confidence: 99%

“…Polynlerization mixtures for kinetic studies were prepared as described in an earlier study (4). The initial monomer concentration was 3.2 M, and the total stannic chloride concentration 0.185 M ; the temperature was norlnally -78.5"C but some measurements were made at -63°C.…”

Section: Procec1111ementioning

confidence: 99%

“…The magnitude of the change increases with stannic chloride concentration and with decrease in temperature. After due allowance for phenol dimerization, the results are interpreted (4) in terms of complex formation between stannic chloride and the phenol.…”

Section: Complex Formation Between Alkylyl~enols and Stannicmentioning

confidence: 99%

“…With most metal halides, a coinitiator of isobutene in ethyl chloride when stannic chloride such as water (3) or trichloracetic acid (2) is also required. Polymerizations proceed at measurable rates at -78.5"C with stannic chloride as the Lewis acid and alkylphenols as coinitiators (4); the polymerization mixtures are homogeneous over a wide range of reactant concentrations. Phenolic coinitiators have the advantage that the number, type, and position of alkyl substituents can be varied, and is used as initiator (4).…”

Section: Introductionmentioning

confidence: 99%

“…Polymerizations proceed at measurable rates at -78.5"C with stannic chloride as the Lewis acid and alkylphenols as coinitiators (4); the polymerization mixtures are homogeneous over a wide range of reactant concentrations. Phenolic coinitiators have the advantage that the number, type, and position of alkyl substituents can be varied, and is used as initiator (4). Over the concentration ranges studied, the rate continuously increased with phenol concentration for the coinitiators 2,6-dimethylphenol and 2,3,4,6-tetramethylphenol.…”

Section: Introductionmentioning

confidence: 99%

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The dual role of the coinitiator in the cationic polymerization of isobutene

Russell¹,

Vail²

1979

Can. J. Chem.

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. Can. J. Chem. 57,2355Chem. 57, (1979. The influence of 2,4-and 2,6-dimethylphenol, 2,3,6-and 2,4,6-trimethylphenol, 2,3,4,6-and 2,3,5,6-tetramethylphenol, 2,6-diisopropylphenol, 2-rert-butyl-4-methylphenol and 2,4-di-tert-butylphenol on the stannic chloride initiated polymerization of isobutene has been investigated. At -78.S°C and with 0.185 M stannic chloride, these phenols act as coinitiators.Rates of polymerizaiton reach maximum values at phenol concentrations which depend greatly on the number and positions of alkyl substituents; molecular weights decrease continuously with phenol concentration. Phenols without 4-substituents are incorporated in polyisobutenes as end groups and those with 4-substituents give rise largely to olefinic end groups. Termination of polymerization occurs mainly by attack at a free 4-position or at the O H group. The initial ferf-butyl carbenium ion is more readily terminated by 2,6-di-terr-butylphenol than the polymer carbenium ion.The rate and molecular weight results are interpreted in terms of a simplified reaction scheme in which termination occurs spontaneously or by reaction with uncomplexed phenol. Rate constants for termination by methyl-substituted phenols are of the order of one tenth of the propagation rate constant while those for 2-rerr-butyl-4-alkylphenols are about one hundredth of the propagation rate constant.On a etudik l'influence des dimCthyl-2,4 (et -2,6), des trimkthyl-2,3,6 (et -2,4,6), des tetramethyl-2,3,4,6 (et -2,3,5,6), du diisopropyl-2,6, du rerr-butyl-2 methyl-4 et du di-tert-butyl-2,4 phenols sur la polymerisation de l'isobutene catalysee par le chlorure stannique. A -78.0j0C et avec 0.18 M de chlorure stannique, ces phenols agissent comme coinitiateurs. Les taux de polymCrisation atteignent des valeurs maximales a des concentrations de phCnols qui dependent grandement du nombre et de la position des substituants alkyles; les poids moleculaires diminuent progressivement avec la concentration de phenol. Les phenols qui ne portent pas de substituants en position 4 sont incorpores dans les polyisobutylenes sous forme de groupes terminaux; ceux qui portent un substituant en position 4 donnent principalement lieu a des groupes terminaux portant des liaisons doubles. La terminaison de la polymerisation se produit principalement par une attaque au niveau de la position 4 vacante ou du groupe OH.Le carbocation rerr-butyle initial est plus facilenlent piegk par le di-re1.r-butyl-2,6 phCnol que le carbocation du polymere.On interprete la cinCtique et les poids moleculaires en termes d'un schCma reactionnel simplifiC dans lequel la terminaison se produit spontanement ou par reaction avec un phCnol qui n'est pas complexC. Les constantes de vitesse pour la terminaison par des phCnols porteurs de groupes mCthyles sont environ un dixieme de la constante de vitesse de propagation alors que celles des rerr-butyl-2 alkyl-4 phCnols sont Cgales a un centieme de la constante de vitesse de propagation.[Traduit par le journal]Introduction the influence of particular var...

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Section: Mnterinlsmentioning

confidence: 99%

Section: Procec1111ementioning

confidence: 99%

Section: Complex Formation Between Alkylyl~enols and Stannicmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The dual role of the coinitiator in the cationic polymerization of isobutene

Russell¹,

Vail²

1979

Can. J. Chem.

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Macromonomers based on low‐molecular‐weight polyisobutenes

Maenz

Stadermann

1996

Angew. Makromol. Chem.

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Radically polymerizable macromonomers were synthesized by alkylation, epoxidation and SH-en addition of low-molecular-weight polyisobutenes followed by esterification with methacrylic acid derivatives. Highly functionalized products (1 95%) can be obtained from polyisobutenes with double bond content G 1 by separation of non-functionalized polymer by column chromatography. ZIJSAMMENFASSUNG:.Auf der Basis niedermolekularer Polyisobutene wurden durch Alkylierung, Epoxidierung und SH-en-Addition sowie anschliel3ende Veresterung mit Methacrylsaiirederivaten radikalisch polymerisierbare Makromonomere hergestellt. Durch chromatographische Abtrennung unfunktionalisierter Polyisobutenanteile konnen hochfunktionalisierte Produkte (2 95%) auch aus Polyisobutenen erhalten werden, welche Doppelbindungsgehalte 4 1 aufweisen.

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Synthesis of phenol‐terminated polyisobutylene: Competitive chain transfer reactions

Rooney

1980

J of Applied Polymer Sci

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SynopsisPolymerizations of isobutylene initiated by either aluminum trichloride or tin tetrachloride were conducted in the presence of alkyl phenols in both n-heptane and methylene dichloride solutions at temperatures between -10 and -7OOC. The resultant polymers contained both unsaturated and phenolic endgroups in varying proportions dependent upon reaction conditions. Increased phenol concentrations in the polymerization medium resulted in decreased polymer molecular weights and increased phenol endgroup content. Increased reaction temperature reduced polymer molecular weights and phenol endgroup content. Chain lengths governed by ring alkylation were found to be less sensitive to polymerization temperature than those determined by other modes of chain transfer.

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Complexes of stannic chloride and alkyl phenols and the influence of these complexes and of free phenol on the cationic polymerization of isobutene

Cited by 13 publications

References 2 publications

The dual role of the coinitiator in the cationic polymerization of isobutene

The dual role of the coinitiator in the cationic polymerization of isobutene

Macromonomers based on low‐molecular‐weight polyisobutenes

Synthesis of phenol‐terminated polyisobutylene: Competitive chain transfer reactions

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