Synthesis of (co-)polyethylene with broad molecular weight distribution by the heterogenous Ziegler–Natta catalysts via one-pot strategy

“…inactivated MgCl 2 has a needle-like structure [14]. At 30° 2θ and 35° 2θ, inactivated MgCl 2 exhibits intense intermediate reflection peaks which result from the diagonal planes in the needle-like structure.…”

Section: Introductionmentioning

confidence: 98%

Heterogeneous Ziegler–Natta catalysts with various sizes of MgCl2 crystallites: synthesis and characterization

et al. 2016

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“…14 HDPE is among the most demanded thermoplastic polymers with variable micro structures and vast ranges of applications. [15][16][17] There are four grades of HDPE (film, injection, pipe, and blow molding) depending on its processing techniques, and each one is best suited for different applications.…”

Section: Introductionmentioning

confidence: 99%

Structure–property relationship in film and blow molding type high‐density polyethylene polymers from a slurry‐process industrial plant

Mansouri

Emami

Yousefi

et al. 2022

J of Applied Polymer Sci

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In this study, the microstructural, flow, and mechanical properties of two commercially available high‐density polyethylene (HDPE) samples with different particle sizes were quantified. Specifically, two different blow molding and film grade HDPEs produced by the same catalyst under different conditions were acquired in powder form after dryer section of an industrial plant. They were fractioned according to their particle sizes into six samples: ≤125, 125–200, 200–315, 315–400, 400–500, and ≥ 500 μm. According to sieve analysis, the film grade (D50 = 304 μm) had larger particle sizes related to the counterpart injection sample (D50 = 289 μm). A peak value in density, bulk density, viscosity molecular weight (Mv), melt flow index (MFI), and comonomer content characteristics was found in the particles with the diameter of 125–200 μm in both samples, indicating extremely non‐homogeneity of these HDPE samples. Chemical composition distribution (CCD) of the as received polymers as well as sieved fractions was surveyed via SSA or TREF analyses. The film sample represented lower MFI and density and higher Mv and comonomer content in all fractions, originated from different reactor conditions during the samples synthesis, which translate into improved mechanical properties comparing with the blow molding sample.

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“…In the previous research, we synthesized four kinds of alkoxy silane compounds employed as IEDs for ethylene polymerization to obtain broad molecular weight distribution by the heterogeneous Ziegler–Natta catalysts via one-pot strategy [ 22 ]. In the present research, two kinds of novel cyclo alkoxy silane compounds were synthesized and employed as EEDs based on the spherical MgCl 2 supported Ziegler–Natta catalysts.…”

Section: Introductionmentioning

confidence: 99%

Study on Hydrogen Sensitivity of Ziegler–Natta Catalysts with Novel Cycloalkoxy Silane Compounds as External Electron Donor

Wang

et al. 2016

Polymers

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Two novel cycloalkoxy silane compounds (ED1 and ED2) were synthesized and used as the external electron donors (EEDs) in Ziegler-Natta catalysts with diethyl 2,3-diisopropylsuccinate as internal electron donor. The results indicated that the Ziegler-Natta catalysts using ED1 and ED2 as EEDs had high catalytic activities and good stereoselectivities. The melt flow rate (MFR) and gel permeation chromatography (GPC) results revealed that the obtained polypropylene has higher MFR and lower average molecular weights than the commercial EED cyclohexyl methyl dimethoxysilane. The differential scanning calorimetry (DSC) results indicated that new isospecific active centers formed after the introduction of new external donors. The work implied that the novel EEDs could improve the hydrogen sensitivities of the catalyst system and obtain polymers with high melt flow rate.

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Synthesis of (co-)polyethylene with broad molecular weight distribution by the heterogenous Ziegler–Natta catalysts via one-pot strategy

Cited by 13 publications

References 43 publications

Heterogeneous Ziegler–Natta catalysts with various sizes of MgCl2 crystallites: synthesis and characterization

Heterogeneous Ziegler–Natta catalysts with various sizes of MgCl2 crystallites: synthesis and characterization

Structure–property relationship in film and blow molding type high‐density polyethylene polymers from a slurry‐process industrial plant

Study on Hydrogen Sensitivity of Ziegler–Natta Catalysts with Novel Cycloalkoxy Silane Compounds as External Electron Donor

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