Cationic Polymerization of Isobutylene Using AlCl<sub>3</sub>OBu<sub>2</sub> as a Coinitiator: Synthesis of Highly Reactive Polyisobutylene

Vasilenko, Irina V.; Frolov, Alexander N.; Kostjuk, Sergei V.

doi:10.1021/ma1009275

Cited by 85 publications

(103 citation statements)

References 36 publications

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“…Until recently, only BF 3 ‐based initiating systems, i.e., complexes of BF 3 with alcohols or ethers in hexanes, are known to produce HR PIB containing 75–85% of exo ‐olefin end groups (BASF process) at elevated temperatures (from −30 to 0 °C) 21, 22. Very recently, we discovered that the use of AlCl 3 in a form of complex with ether allowed to synthesize HR PIB containing 85–95% of exo ‐olefin end groups in contrast to conventional PIB typically obtained using neat AlCl 3 23, 24. The similar initiating systems were later proposed by Wu and coworkers 25, 26.…”

Section: Room Temperature Polymerization Of Ibmentioning

confidence: 99%

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Cationic polymerization of isobutylene at room temperature

Kostjuk¹,

Yeong²,

Voit³

2012

J. Polym. Sci. A Polym. Chem.

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This review highlights recent approaches toward polyisobutylene (PIB) by an energy efficient room temperature cationic polymerization. Special focus is laid on our own work using modified Lewis acids and nitrile-ligated metal complexes associated with weakly coordinating anions. In both cases, suitable conditions have been found for efficient production of PIB characterized by medium to low molar masses and a high content of exo double bonds as end groups-the typical features of highly reactive PIB, an important commercial intermediate toward oil and gasoline additives. These and other approaches demonstrate that the cationic polymerization of isobutylene is still not fully explored, and new innovative catalyst systems can lead to surprising results of high commercial interest.

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Section: Room Temperature Polymerization Of Ibmentioning

confidence: 99%

“… A representative 1 H NMR spectrum of polyisobutylene synthesized with CumOH/AlCl 3 OBu 2 initiating system in CH 2 Cl 2 / n ‐hexane. (Reproduced from ref 23,. with permission from American Chemical Society).…”

Section: Room Temperature Polymerization Of Ibmentioning

confidence: 99%

Cationic polymerization of isobutylene at room temperature

Kostjuk¹,

Yeong²,

Voit³

2012

J. Polym. Sci. A Polym. Chem.

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“…The polymerization of IB could only be initiated with water, but monomer conversions and exo-olefin content (60−70%) were lower and polydispersity indices (PDIs) were much higher than in polar solvents. 9 Mechanistic studies suggested that the reaction of water with AlCl 3 ·R 2 O yields H + AlCl 3 OH − that initiates polymerization and releases free ether, which subsequently abstracts a β-proton from the growing chain end before it diffuses from the immediate vicinity of the polymer cation. 12 Since the AlCl 3 ·R 2 O complex yields PIB exoolefins with high selectivity only in polar solvent and only water initiates the polymerization, we have studied other Lewis acid/ Lewis base complexes that could potentially initiate polymerization of IB in conjunction with conventional cationic initiators in nonpolar solvents.…”

Section: ■ Introductionmentioning

confidence: 99%

Polymerization of Isobutylene by GaCl₃ or FeCl₃/Ether Complexes in Nonpolar Solvents

et al. 2012

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The carbocationic polymerization of isobutylene (IB), co-initiated by GaCl 3 or FeCl 3 ·dialkyl ether 1:1 complexes has been investigated in hexanes in the −20 to 10°C temperature range. In contrast to AlCl 3 ·diisopropyl ether (AlCl 3 ·i-Pr 2 O) complexes, 1 GaCl 3 ·i-Pr 2 O and FeCl 3 ·i-Pr 2 O readily co-initiate polymerization with 2-chloro-2,4,4-trimethylpentane (TMPCl) or tert-butyl chloride (t-BuCl) in the presence or absence of proton trap. In the absence of proton trap, chain transfer to monomer readily proceeded, resulting in close to complete monomer conversion and up to 85% exo-olefinic end group content. Diisopropyl ether complexes gave the highest polymerization rates, while nonbranched alkyl ether complexes were completely inactive. A polymerization mechanism is proposed to involve ether-assisted proton elimination to yield PIB exo-olefin, and the abstracted proton can subsequently start a new polymer chain by protonation of IB. Alternatively PIB + may be deactivated by ion collapse to yield PIBCl, which can be reactivated by the Lewis acid. The reasons for the difference in behavior between the Ga and Fe catalysts and the Al-based catalysts are described. ■ INTRODUCTIONLow molecular weight (M n ∼ 500−5000 g/mol) olefin end functional PIB is a precursor to motor oil and fuel additives. Currently two major industrial methods are utilized to produce low molecular weight IB homo or copolymers with olefinic end groups. The "conventional" method uses a C4 mixture and AlCl 3 or EtAlCl 2 based catalyst systems, which provides polybutenes with high trisubstituted olefinic content. 2,3 The other method employs pure IB and uses BF 3 complexes with either alcohols or ethers as catalysts, yielding highly reactive PIB (HR PIB) with high exo-olefinic end-group content. 4 In contrast to the trisubstituted olefins of conventional polybutenes, PIB exo olefins readily react with maleic anhydride in a thermal ene reaction to produce PIB succinic anhydride and subsequently polyisobutenyl succinimide ashless dispersants. Since chlorination is not necessary for maleation of HR PIB, the final product does not contain any chlorine, making HR PIB more desirable than conventional polybutenes.In recent decades, several new methods for the synthesis of HR PIB have been reported. For example, PIBCl was selectively dehydrochlorinated by a bulky base, e.g., potassium tertbutoxide to yield HR PIB. 5 Storey et al. used living cationic polymerization of IB at −80°C to obtain living PIB, which was then end-quenched with sterically hindered bases 6 or sulfides. 7 Another method used to produce HR PIB, developed by Kuhn and co-workers, involves inorganic/organometallic catalysts with weakly coordinating anions in dichloromethane (DCM). 8 Recently, Kostjuk and Wu independently reported that at moderate temperatures AlCl 3 ·dibutyl ether 9 (AlCl 3 ·Bu 2 O) and AlCl 3 ·i-Pr 2 O 10 complexes in DCM or DCM/hexanes 80/20 (v/ v) mixtures give HR PIB with exo-olefinic end-groups in excess of 90%. Shortly thereafter, Wu and co-workers also rep...

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“…However, AlCl 3 has poor solubility in organic solvents . To enhance the selectivity of polymerization reaction, ethyl acetate (EtOAc) was introduced to AlCl 3 for developing an AlCl 3 .EtOAc complex . This coinitiator complex was utilized herein to synthesize laccol polymer (LP) and laccol‐styrene copolymers.…”

Section: Introductionmentioning

confidence: 99%

Synthesizing radiation‐hard polymer and copolymers usinglaccolmonomers extracted from lacquer treetoxicodendron succedaneavia cationic polymerization

Arachchilage

Patel

Harmon

2019

Polymer Engineering & Sci

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In recent years, lacquer chemistry stimulated more attention from the scientific community due to its environmental friendly applications. Additionally, the “laccol” possesses promising radiation resistance due to its highly crosslinked polymer network. In nature, lacquer polymerization is induced via enzymatic radical initiation. Herein, as a novel approach, lacquer polymer was synthesized via cationic polymerization with aluminum chloride‐ethyl acetate coinitiator. This approach was further improved by polymerizing copolymers of laccol and styrene designed for use in radiation‐hard materials. The infrared spectroscopic data clearly provide evidence for reactions with trans conjugated double bonds present in long side chain (988 and 966 cm−1 are bending vibrations of conjugated alkenes) of laccol monomer accompanying polymerization. This was further verified with proton nuclear magnetic resonance analysis. An increase in hardness was observed for all the compositions: remarkably for neat laccol polymer, and 90% and 70% laccol‐styrene copolymers after the gamma irradiation using Co‐60 gamma irradiator. Properties such as thermal stability and hardness were improved after irradiation due to the increase in physical and small amounts of chemical crosslinking. Therefore, the developed materials are suitable candidates to produce radiation‐hard polymer and copolymer coatings for aerospace operations, nuclear reactors, and medicinal and automobile sectors. POLYM. ENG. SCI., 59:1611–1623 2019. © 2019 Society of Plastics Engineers

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Cationic Polymerization of Isobutylene Using AlCl₃OBu₂ as a Coinitiator: Synthesis of Highly Reactive Polyisobutylene

Cited by 85 publications

References 36 publications

Cationic polymerization of isobutylene at room temperature

Cationic polymerization of isobutylene at room temperature

Polymerization of Isobutylene by GaCl₃ or FeCl₃/Ether Complexes in Nonpolar Solvents

Synthesizing radiation‐hard polymer and copolymers usinglaccolmonomers extracted from lacquer treetoxicodendron succedaneavia cationic polymerization

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Cationic Polymerization of Isobutylene Using AlCl3OBu2 as a Coinitiator: Synthesis of Highly Reactive Polyisobutylene

Cited by 85 publications

References 36 publications

Cationic polymerization of isobutylene at room temperature

Cationic polymerization of isobutylene at room temperature

Polymerization of Isobutylene by GaCl3 or FeCl3/Ether Complexes in Nonpolar Solvents

Synthesizing radiation‐hard polymer and copolymers usinglaccolmonomers extracted from lacquer treetoxicodendron succedaneavia cationic polymerization

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Cationic Polymerization of Isobutylene Using AlCl₃OBu₂ as a Coinitiator: Synthesis of Highly Reactive Polyisobutylene

Polymerization of Isobutylene by GaCl₃ or FeCl₃/Ether Complexes in Nonpolar Solvents