Micromixing enhanced synthesis of HRPIBs catalyzed by EADC/bis(2-chloroethyl)ether complex

Zhu, Shenlin; Lu, Yangcheng; Faust, Rudolf

doi:10.1039/c7ra05246d

Cited by 19 publications

(19 citation statements)

References 32 publications

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“…In any case, other than a confusing shift in weather conditions, sub-atomic dissemination additionally assumes a key job in achieving mass movement in micromixers [14] where the role of catalysis is important. In fact, in-stream routines where the stream is carefully laminar, species blending happens for the most part because of atomic dispersion between layers of various fixations [15].…”

Section: Introductionmentioning

confidence: 99%

RETRACTED: Numerical Simulation of Micromixing of Particles and Fluids with Galloping Cylinder

Abdelmalek

Jamalabadi

2020

Symmetry

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Micromixers are significant segments inside miniaturized scale biomedical frameworks. Numerical investigation of the effects of galloping cylinder characteristics inside a microchannel Newtonian, incompressible fluid in nonstationary condition is performed. Governing equations of the system include the continuity equation, and Navier–Stokes equations are solved within a moving mesh domain. The symmetry of laminar entering the channel is broken by the self-sustained motion of the cylinder. A parameter study on the amplitude and frequency of passive moving cylinder on the mixing of tiny particles in the fluid is performed. The results show a significant increase to the index of mixing uses of the galloping body in biomedical frameworks in the course of micro-electromechanical systems (MEMS) devices.

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Section: Introductionmentioning

confidence: 99%

RETRACTED: Numerical Simulation of Micromixing of Particles and Fluids with Galloping Cylinder

Abdelmalek

Jamalabadi

2020

Symmetry

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“…Catalytic chain transfer polymerization (CCTP) in nonpolar solvents at moderate temperatures has developed into one of the most adaptable polymerization techniques for the synthesis of highly reactive polyisobutylene (HRPIB) in recent years. − Low molecular weight HRPIB ( M n = 500–5000 g/mol) is a valuable precursor in the preparation of motor oil and fuel auxiliaries. − Initially, metal halide (AlCl 3 , GaCl 3 , FeCl 3 , etc.) ether complexes (MX n ·ether) were shown to be better catalysts for the synthesis of HRPIB at moderate temperatures compared to traditional catalysts. − However, their application in nonpolar solvents is limited because of poor solubility, which affects the polymerization rate. − This issue was lately overcome by employing alkylaluminum dichloride ether complexes as hydrocarbon soluble catalysts. − We have shown that the ethylaluminum dichloride (EADC)·bis(2-chloroethyl) ether (CEE) complex is an effective catalyst, which not only polymerizes pure IB feed but also polymerizes mixed C4 olefin feeds at 0–10 °C to yield up to 88% exo-olefin content . In these studies, polymerization conditions and products have been optimized for a batch reactor.…”

Section: Introductionmentioning

confidence: 99%

“…In these studies, polymerization conditions and products have been optimized for a batch reactor. However, polymerization in a continuous stirred tank reactor (CSTR) under steady state conditions is of industrial interest, as a way of significantly increasing the mixing and temperature control that results in products with lower PDI …”

Section: Introductionmentioning

confidence: 99%

Controlled Catalytic Chain Transfer Polymerization of Isobutylene in the Presence of tert-Butanol as Exo-Enhancer

Rajasekhar¹,

Emert

Wolf³

et al. 2018

Macromolecules

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Catalytic chain transfer polymerization (CCTP) of isobutylene in the presence of alcohol as an exo-enhancer with tert-butyl chloride/ethylaluminum dichloride (EADC)·bis(2-chloroethyl) ether (CEE) has been investigated in hexanes at 0 °C. Increasing exo-olefin content was observed with increasing steric bulkiness of the alkyl group of the alcohol, i.e., tert-butyl > isopropyl > methyl. Here, we report that tert-butanol (t-BuOH) is an excellent exo-enhancer compared to other tert-alcohols such as tert-amyl alcohol (AmOH), 2-methyl-2-pentanol (MPOH), and 3-ethyl-3-pentanol (EPOH). The aromatic tert-alcohol cumyl alcohol was not an exo-enhancer but acted as an initiator. In the reaction of EADC.CEE and t-BuOH, t-butoxyaluminum dichloride (t-BuOAlCl2) was formed, which is the real exo-enhancer and is not stable at room temperature. Molecular weights were virtually unchanged in the presence t-BuOAlCl2 with [t-BuOAlCl2]:[EADC.CEE] < 0.5, and exo-olefin content increased ∼15% relative to polymerization in the absence of t-BuOAlCl2. This is presumably due to stabilization of the cation by t-BuOAlCl2 which slows isomerization of the PIB+. Stabilization of the cation was confirmed by 1H NMR and UV–vis spectroscopy at 0 °C by adding t-BuOAlCl2 to the diphenylmethyl cation, a representative stable cation. The rate constant of chain transfer (k tr) was determined to be 2 × 108 L mol–1 s–1 at 0 °C, which is not affected by t-BuOAlCl2. Addition of an exo-enhancer is especially important for polymerization at CSTR conditions at low steady state monomer concentrations. This is the first report identifying the role of alcohols in CCTP and opens new vistas in the synthesis of highly reactive polyisobutylene.

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“…[39] In addition, this initiating system also displayed improved efficiency toward synthesis of HR PIB under micromixing conditions. [40] In summary, t BuCl/EtAlCl 2 ÂCEE and H 2 O/ RAlCl 2 ÂO i Pr 2 initiating systems allowed to synthesize HR PIB with high exo-olefin content in non-polar reaction media. The great advantage of first initiating system is the use of initiator ( t BuCl) that allows controlling precisely the reaction rate and performing fast polymerization (<10 min for complete monomer conversion).…”

Section: H 2 O/ralcl 2 / I Pr 2 O Initiating Systemmentioning

confidence: 96%

Homogeneous and heterogeneous catalysts for the synthesis of highly reactive polyisobutylene: discovery, development and perspectives

Vasilenko

Kostjuk

2021

Journal of Macromolecular Science, Part A

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In this article, the current state and future perspectives in the application of complexes of Lewis acids with ethers in the synthesis of highly reactive polyisobutylene (HR PIB) were critically reviewed. The complexes of metal halides with ethers showed good activity and regioselectivity in the synthesis of HR PIB only in polar solvents due to their poor solubility in hydrocarbons. In strong contrast, HR PIB with high exo-olefin end group content was synthesized in non-polar nhexane using fully soluble in hydrocarbons complexes of alkylaluminum dichlorides as catalysts. The further improvement in the synthesis of HR PIB was achieved using heterogeneous catalysts (acidic ionic liquids or liquid coordination complexes), which provides polyisobutylenes with high exo-olefin end group content in conjunction with low polydispersity.

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Micromixing enhanced synthesis of HRPIBs catalyzed by EADC/bis(2-chloroethyl)ether complex

Abstract: Better mixing could produce more active centers to accelerate the polymerization by promoting the consumption of carbonium ions.

Cited by 19 publications

References 32 publications

RETRACTED: Numerical Simulation of Micromixing of Particles and Fluids with Galloping Cylinder

RETRACTED: Numerical Simulation of Micromixing of Particles and Fluids with Galloping Cylinder

Controlled Catalytic Chain Transfer Polymerization of Isobutylene in the Presence of tert-Butanol as Exo-Enhancer

Homogeneous and heterogeneous catalysts for the synthesis of highly reactive polyisobutylene: discovery, development and perspectives

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