Lanthanide complexes mediated coordinative chain transfer polymerization of conjugated dienes

Wang, Feng; Liu, Heng; Hu, Yanming; Zhang, Xuequan

doi:10.1007/s11431-018-9256-6

Cited by 19 publications

(14 citation statements)

References 55 publications

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“…[4] The living coordinative polymerization constitutes a reliable alternative to perform controlled polymerizations of conjugated dienes; [5,6] nevertheless, this kind of polymerization produces only one polymer chain per active metal center in ideal reaction conditions, which can be very expensive because of the relatively high catalyst concentrations required by the technique and the high costs of the catalyst. [7] For these reasons, there still exist many reasons to investigate the controlled polymerization of dienes with more economical and efficient catalyst systems.…”

Section: Introductionmentioning

confidence: 99%

Modeling of Isoprene Solution Coordinative Chain Transfer Polymerization

Sá

Cordova

Gómez

et al. 2021

Macro Reaction Engineering

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The present manuscript investigates the solution coordinative chain transfer polymerization (CCTP) of isoprene initiated by the ternary Ziegler‐Natta catalyst system composed by neodymium versatate (NdV3), diisobutylaluminum (DIBAH), and dimethyldichlorosilane. A kinetic mechanism is proposed and the kinetic parameters are estimated to allow the appropriate description of dynamic trajectories of average molecular weights and isoprene conversions obtained in solution CCTP polymerizations for the first time. A data reconciliation strategy is applied to evaluate the amount of DIBAH used as a chain transfer agent, as this very active compound can be consumed by undesired side reactions. Additionally, the impacts of key operation variables on the control of the average molecular weights and monomer conversion are evaluated to elucidate the living nature of the polymerization. As observed experimentally, the temperature effect on the course of the polymerization is not so pronounced as the effect of NdV3, isoprene, and DIBAH initial concentrations. The kinetic mechanism is described better and kinetic constants are estimated more precisely when the dynamic trajectories of average molecular weights are fitted during the whole batch. In this case, the proposed model is able to predict well the experimental trajectories of average molecular weights of the produced polymer and monomer conversion.

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Section: Introductionmentioning

confidence: 99%

Modeling of Isoprene Solution Coordinative Chain Transfer Polymerization

Sá

Cordova

Gómez

et al. 2021

Macro Reaction Engineering

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show abstract

“…As seen in Table , the number of chains in the system was 12.7 times greater than Nd and remained at this level for both first and second steps, maintaining relatively small molecular weight distribution (MWD) and keeping M n grow linearly. Considering potential site of chain transfer, the most probable is the component (3) DIBAH as many earlier research indicated . Data in Table suggest that roughly 60% of DIBAH works as reversible chain transfer site.…”

Section: Resultsmentioning

confidence: 87%

“…Aluminum sites in PMAO (MAO) are not believed to serve as chain transfer sites in Nd/Al/Cl catalyst system as was shown in an earlier work by Wilson, in which MAO was used in the absence of other alkyl aluminum or alkyl aluminum hydride compounds and resulted in 0.6 chains per Nd. Recent review by Wang et al . mentioned about the recent progress of their research on higher performance reversible chain transfer with greater molecular weight range, but the details are not available.…”

Section: Resultsmentioning

confidence: 99%

“…Recent advancement of catalysis, especially those published by Gong, enabled many new applications by using Co‐based catalyst system to achieve part of such conditions but the catalyst dosage remains high. Introduction of reversible chain transfer may be desired to overcome this problem but currently available evidences are not satisfying the desired combination of high polymerization temperature, high enough molecular weight of resulting polymer and reversible chain transfer maintaining low catalyst dosage and living character of growing chains all at once.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis and property of end‐functionalized poly(cis‐1,4‐butadiene) and its application to rubber compound

Ozawa

Takata

2019

J of Applied Polymer Sci

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This article describes the successful quasi-living polymerization of 1,3-butadiene (BD) to high cis content butadiene rubber (HCBR) and the terminal functionalization of HCBR for application to rubber compound. A catalyst system based on neodymium carboxylate and organoaluminum compounds was prepared and employed to polymerize BD. Polymerization resulted in mostly proportional growth of molecular weight to the conversion while maintaining molecular weight distribution in relatively narrow range. The reactivity of chain end after the completion of polymerization was confirmed by comparing UV absorbance of polymers before and after the addition of chromophore compound to the unterminated polymerization mixture, as measured with size exclusion chromatography (SEC). A variety of functionalizing agents, which can provide end-groups of polymer with potential affinity to silica surface, was explored. Among them, compounds with epoxy, ketone, and ketimine groups produced polymers with clear evidences of functionalization. The HCBR functionalized with epoxy-containing alkoxysilane compound was tested in silica-filled rubber compound and showed remarkable improvement of silica dispersity as seen by change of viscoelastic responses.

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“…Lanthanide complexes mediated coordinative chain transfer polymerization of conjugated dienes features catalyst economy, well-controlling over both microstructure and architecture of the resulting polymers, and accessibility for novel (co)polymers [18]. Tremendous advances have been witnessed in the past few years and represent a novel strategy to prepare polydiene synthetic rubbers with controlled high molecular weight and narrow molecular weight distribution, which has reached the practical industrial application level, demonstrating a great potential in the future.…”

Section: +mentioning

confidence: 99%