Cationic polymerization of isobutylene catalyzed by iBuAlCl2 in the presence of ethers: Effect of catalyst pre-activation and mixture of two ethers

Shiman, Dmitriy I.; Vasilenko, Irina V.; Kostjuk, Sergei V.

doi:10.1016/j.polymer.2016.07.014

Cited by 32 publications

(35 citation statements)

References 43 publications

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“…Protons of endo‐end groups (structure B) and coupled polyisobutylene chains (structure D) appeared at 5.15 ppm (peak e) and 4.81 ppm (peak f), respectively. It illustrated that the synthesized polyisobutylene contains predominantly exo‐double bond end groups (90 mol %), while the endo‐end groups (structure B, 7 mol %) and coupled polyisobutylene chains(structure D, 3 mol %) are observed in very minor amounts . It demonstrates that β‐H elimination predominates the chain transfer reaction to form the vinylidene tail end groups (Fig.…”

Section: Synthesis Of Polyisobutylene and Isobutylene–isoprene Copolymentioning

confidence: 92%

Cationic half‐sandwich scandium complex for the synthesis of polyisobutylene with high molecular weight under mild conditions

Shen

et al. 2017

J. Polym. Sci. Part A: Polym. Chem.

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Section: Synthesis Of Polyisobutylene and Isobutylene–isoprene Copolymentioning

confidence: 92%

Cationic half‐sandwich scandium complex for the synthesis of polyisobutylene with high molecular weight under mild conditions

Shen

et al. 2017

J. Polym. Sci. Part A: Polym. Chem.

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“…This was confirmed by the results of polymerization with water as the initiator in the presence or absence of impurities (Supporting Information Table S33–S36). In these experiments, water with EADC · CEE yields H + EADCOH − , which initiates the polymerization. By increasing the concentration of acetone, the polymerization rate decreases, and at [acetone] = [H 2 O] polymerization was absent.…”

Section: Resultsmentioning

confidence: 99%

Catalytic chain transfer polymerization of isobutylene: The role of nucleophilic impurities

Rajasekhar

Haldar

Emert

et al. 2017

J. Polym. Sci. Part A: Polym. Chem.

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Fast polymerization of isobutylene (IB) initiated by tert‐butyl chloride using ethylaluminum dichloride·bis(2‐chloroethyl) ether complex (T. Rajasekhar, J. Emert, R. Faust, Polym. Chem. 2017, 8, 2852) was drastically slowed down in the presence of impurities, such as propionic acid, acetone, methanol, and acetonitrile. The effect of impurities on the polymerization rate was neutralized by using two different approaches. First, addition of a small amount of iron trichloride (FeCl3) scavenged the impurity and formed an insoluble FeCl3··impurity complex in hexanes. The polymerization rate and exo‐olefin content were virtually identical to that obtained in the absence of impurities. Heterogeneous phase scavenger (FeCl3) exhibited better performance than homogenous phase scavengers. In the second approach, conducting the polymerization in wet hexanes, the fast polymerization of IB was retained in the presence of impurities with a slight decrease in exo‐olefin content. 1H NMR studies suggest that nucleophilic impurities are protonated in the presence of water, and thereby neutralized. Mechanistic studies suggest that the rate constant of activation (ka), rate constant of propagation (kp), and rate constant of β‐proton elimination (ktr) are not affected by the presence of impurities. To account for the retardation of polymerization in the presence of impurities, delay of proton transfer to monomer in the chain transfer step is proposed. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3697–3704

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“…However, iPr 2 O has little inuence on isomerization due to steric hindrance, leading to a high content of exo-olen. 32 From these results, it can be concluded that Et 2 O may have a stronger inuence on the rate of b-H abstraction in pure n-hexane, while iPr 2 O may better stabilize the carbocations.…”

Section: Introductionmentioning

confidence: 86%

Tailoring the AlCl₃/iPr₂O/Et₂O initiation system for highly reactive polyisobutylene synthesis in pure n-hexane

2020

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Cationic polymerization of isobutylene catalyzed by iBuAlCl2 in the presence of ethers: Effect of catalyst pre-activation and mixture of two ethers

Cited by 32 publications

References 43 publications

Cationic half‐sandwich scandium complex for the synthesis of polyisobutylene with high molecular weight under mild conditions

Cationic half‐sandwich scandium complex for the synthesis of polyisobutylene with high molecular weight under mild conditions

Catalytic chain transfer polymerization of isobutylene: The role of nucleophilic impurities

Tailoring the AlCl₃/iPr₂O/Et₂O initiation system for highly reactive polyisobutylene synthesis in pure n-hexane

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Cationic polymerization of isobutylene catalyzed by iBuAlCl2 in the presence of ethers: Effect of catalyst pre-activation and mixture of two ethers

Cited by 32 publications

References 43 publications

Cationic half‐sandwich scandium complex for the synthesis of polyisobutylene with high molecular weight under mild conditions

Cationic half‐sandwich scandium complex for the synthesis of polyisobutylene with high molecular weight under mild conditions

Catalytic chain transfer polymerization of isobutylene: The role of nucleophilic impurities

Tailoring the AlCl3/iPr2O/Et2O initiation system for highly reactive polyisobutylene synthesis in pure n-hexane

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Tailoring the AlCl₃/iPr₂O/Et₂O initiation system for highly reactive polyisobutylene synthesis in pure n-hexane