Polymerisation von propylen mit Al‐haltigen und Al‐freien titantrichloriden verschiedener korngrößen. 8. Mitt.. Zur polymerisation mit metallorganischen mischkatalysatoren

Schnecko, Von H.; Dost, W.; Kern, Werner

doi:10.1002/macp.1969.021210114

Cited by 28 publications

(3 citation statements)

References 22 publications

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“…that the catalyst size impacts the catalyst activity by affecting mass and energy-transfer limitations. This is supported by experimental data from Schnecko et al and more recently from Philippaerts et al during slurry polymerization. However, this conclusion remains in contrast with the studies of Dall’Occo et al, who observed an insignificant effect of particle size on catalyst activity.…”

Section: Introductioncontrasting

confidence: 87%

Insight into the Synthesis Process of an Industrial Ziegler–Natta Catalyst

Klaue

Kruck

Friederichs

et al. 2018

Ind. Eng. Chem. Res.

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In Ziegler–Natta catalysis, the catalyst particle size has a strong influence not only on catalyst performance but also on the morphology and particle size distribution of the final polymer particles. Fundamental insight into the catalyst particle formation process is therefore of industrial importance when addressing specific requirements in the final products. In the present work, we fully characterize a single-step catalyst preparation process, which comprises a reactive precipitation of a MgCl2-supported Ziegler–Natta catalyst, through decomposition of the hetero-bimetallic complex, Mg(OR)2·Ti(OR)4, by addition of ethyl aluminum dichloride (EADC). We track the evolution of both of the concentrations of the metals (Mg, Ti, Al) as well as Cl in the liquid phase and the size of the formed catalyst particles. It is observed that the liquid-phase composition is governed by the EADC feed rate under fully Cl-starved conditions. The process can be divided into two stages: The first stage is dominated by the precipitation of the Mg-based support, and the second stage involves complex adsorption–precipitation of the Ti species. The growth of the catalyst particle size occurs only in the first stage and is controlled by the aggregation and breakage events during the MgCl2 precipitation. It follows that the hydrodynamic stress in the reactor plays the essential role in controlling the catalyst size. In the second stage, no further particle growth occurs, not only because of the depletion of Mg in the liquid phase but also because the adsorbed Ti complex stabilizes the particles against aggregation. Finally, we have performed polymerization tests with the prepared catalysts and found that the size distribution of the polymer particles indeed closely replicates the one of the used catalyst particles.

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Section: Introductioncontrasting

confidence: 87%

Insight into the Synthesis Process of an Industrial Ziegler–Natta Catalyst

Klaue

Kruck

Friederichs

et al. 2018

Ind. Eng. Chem. Res.

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“…The inhibiting effect of CO and the subsequent recovery of polymerization activity may be interpreted in terms of the following reaction sequence proposed by Caunt ( where is a free coordination site and -CH2P is a polymer chain. Schnecko et al (1969Schnecko et al ( , 1975 using other methods in the slurry polymerization of propene with 6-TiC13/A1(CzH5)zC1 catalyst. Examples of irreversible insertion of CO into a titanium-alkyl bond have been reported by Fachinetti et al (1974Fachinetti et al ( ,1977 in the reaction of CO with dicyclopentadienylhaloalkyltitanium, (q5-C5H5)2Ti(X)R, to give the acyl derivative, (v5-C6H5),Ti-(X)(COR).…”

Section: M"mentioning

confidence: 99%

Gas-phase polymerization of propene with the supported Ziegler catalyst: TiCl4/MgCl2/C6H5COOC2H5/Al(C2H5)3

Doi¹,

Murata²,

Yano³

et al. 1982

Ind. Eng. Chem. Prod. Res. Dev.

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The gas-phase polymerization of propene with the MgCI,-supported Ti CI , / C, H, COOC, H, catalyst in conjunction with AI(C2H,), has been investigated. The rate of polymerization depends on both titanium content and surface area of the MgCITsupported catalyst and decreases with the polymerization time. The number of active centers in the catalyst at different polymerization times is estimated by the inhibition method using carbon monoxide. As a result, the number of active centers decreasesjuring the course of polymerization, but the mean propagation rate constant k , remains constant. The value of k , is one order of magnitude larger than that in the conventional TiCI, catalyst.Potassium-graphite intercalation compounds were shown to catalyze the addition of ethylene to C, to C, n-olefins to give a preponderance of linear olefinic products. Addition of ethylene to 2-pentenes with KC, -KC, , mixtures made from pure graphite gave 57% linear 3-heptenes and 37% 3-ethyI-1-pentene compared to 19% 3-heptenes and 54 % 3-ethyl-1-pentene produced at similar conditions with catalyst prepared from potassium metal dispersion.With catalysts varying from KC8 to KC24, the rate of reaction was proportional to the amount of KC, and not to the amount of potassium. Varying the reaction temperature had only a small effect on reaction rates. Olefin isomerization was catalyzed by potasslum-graphite catalysts made from graphite containing a significant amount of ash. A new method of preparing potassium-graphite intercalation compounds by reaction of graphite with molten potassium dispersions in liquid hydrocarbon is described.

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“…On the other hand, AlC13, present in another reference binary chloride, i.e., AlC1~3TiC13, participates actively in ligand exchange with AlR3, since it produces alkylaluminum halide^.^ The layer lattice structure of y-Tic13 is capable of incorporating MgClz and also MnC12 even though the latter yields a larger deformation of the Tic13 structure, due to the higher ionic radius of Mn2+ (0.82 A) with respect to that of Mg2+ (0.65 A) and of Ti3+ (0.67 A).l As a consequence, the 'solid solutions of the binary chlorides described in this work lead to very disordered structures when the difference between the ionic radius of Ti3+ and that of the second metal ion is significant.l From these disordered structures a high number of exposed Ti atoms, i e., potential active centers,5 can result, and this means, in principle, high catalyst efficiency. 6 This potentiality can become an actual result when the environment of the Ti atom can stabilize the active centers resulting from the interaction with AlR3. This seems the caseof MgC1~3TiC13 solid solution, whereas AlC13~3TiC13, which shows a more ordered crystalline structure,l may loose many potential active centers because of the strong interaction with AIR3 and the preferred coordination of RzAlCl formed inside the solid solution.…”

Section: Introductionmentioning

confidence: 99%

Novel binary chlorides containing TiCl₃ as components of coordination catalysts for ethylene polymerization. II. Behavior of the resulting catalyst systems

Greco

Bertolini

Bruzzone

et al. 1979

J of Applied Polymer Sci

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Synopsis /Binary chlorides described in part I yielded very active catalyst systems for HDPE synthesis when they were associated with (i-C4H&Al. Very high initial polymerization rates were observed for systems bases on MnC12-TiC13, MnC1~2TiC13, or FeC12~2TiC13 (III), but high yields, i.e., above 30 kg polymer/g Ti, could be reached only using moderate pressure of ethylene. Hydrogen consumption during ethylene polymerization was observed in the case of catalysts based on AlC1~3TiC13, CrC13-3TiC13, and other binary chlorides containing elements of the VIII group. Relevant amounts of ethane were found in the case of systems 111, V, and VIII. All the mixed chlorides studied were able to reduce cyclohexene in the presence of H2 and (i-CdH&Al, even though with different kinetic courses. Compounds 11,111, V, and VIII and (MgC12)1,yTiC13 and AlCl~3TiC13 were very active. The results have been explained on the basis of soluhilization processes involving the heterogeneous catalysts which actually were experimentally verified during cyclohexene reduction. Analogous processes may occur also during HDPE synthesis. INTRODUCTIONIn part I,' new binary chlorides CrC13-3(TiC13) (I), MoC1r3TiC13 (II), FeClY 2TiC13 (III), MnC1~2TiC13 (IV), NiC1~2TiC13 (V), and MnCl2.TiCl3 (VI) containing usually the y-modification of TiC13 were described. Their ability to give catalyst systems for the low-pressure polymerization of ethylene when associated to A1R3 was also mentioned.In this paper, the dependence of the polymerization rate on time and the influence of hydrogen used as regulator of the polymer molecular weight on some side processes, i.e., monomer hydrogenation and catalyst solubilization, are presented. Relevant differences have been encountered among the systems based on different binary halides and depending on the element associated with Tic13 in the solid solution. RESULTS AND DISCUSSION Ethylene PolymerizationProducts 1 through VI, and also VTil.lC16.~ (VII) and CoTil.6C16.6 (VIII), have been associated with Al(i-C4H9)3 to investigate their catalytic activity toward low-pressure ethylene polymerization. By working in the presence of HZ as Journal of Applied Polymer Science, Vol. 23,1333-1344(1979 Table I were obtained. They are referred to the catalytic activity shown by AlC13-3TiC13, while the possible contribution to the catalyst efficiency of the binary chloride due to the second transition metal has been neglected only in a first approximation. In fact, this assumption is not rigorous.2 However, Table I shows that catalyst systems based on 111, IV, and VI are about three times more efficient than the system based on AlC13-3TiC13. The hydrogen sensitivity, i.e., the dependence of the polymer molecular weight on the Hz concentration, can be considered satisfactory in the case of VI, whereas it is rather poor in the case of I11 and I.In part I, mention has been made of the difficulty to relate the overall catalyst efficiency to the surface area ( S A ) value of the binary chlorides used. Analogous difficulties in correlating th...

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Polymerisation von propylen mit Al‐haltigen und Al‐freien titantrichloriden verschiedener korngrößen. 8. Mitt.. Zur polymerisation mit metallorganischen mischkatalysatoren

Cited by 28 publications

References 22 publications

Insight into the Synthesis Process of an Industrial Ziegler–Natta Catalyst

Insight into the Synthesis Process of an Industrial Ziegler–Natta Catalyst

Gas-phase polymerization of propene with the supported Ziegler catalyst: TiCl4/MgCl2/C6H5COOC2H5/Al(C2H5)3

Novel binary chlorides containing TiCl₃ as components of coordination catalysts for ethylene polymerization. II. Behavior of the resulting catalyst systems

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Polymerisation von propylen mit Al‐haltigen und Al‐freien titantrichloriden verschiedener korngrößen. 8. Mitt.. Zur polymerisation mit metallorganischen mischkatalysatoren

Cited by 28 publications

References 22 publications

Insight into the Synthesis Process of an Industrial Ziegler–Natta Catalyst

Insight into the Synthesis Process of an Industrial Ziegler–Natta Catalyst

Gas-phase polymerization of propene with the supported Ziegler catalyst: TiCl4/MgCl2/C6H5COOC2H5/Al(C2H5)3

Novel binary chlorides containing TiCl3 as components of coordination catalysts for ethylene polymerization. II. Behavior of the resulting catalyst systems

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Novel binary chlorides containing TiCl₃ as components of coordination catalysts for ethylene polymerization. II. Behavior of the resulting catalyst systems