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

Abstract

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.

Polymerization of olefins through heterogeneous catalysis. XVII. Experimental study and model interpretation of some aspects of olefin polymerization over a TiCl4/MgCl2 catalyst

“…This is reported for both slurry phase systems 14,15 and gas phase reactor systems. 30 Consequently, an experimental study focusing only on ethylene homopolymerization with different Al/Ti ratios was conducted. A reaction temperature of 50ЊC and a catalyst aging time of Ç 25 min were employed.…”

Propylene polymerization with Mg(OEt)2/benzoyl chloride/TiCl4–triethyl aluminum/external donor catalyst systems

“…Upon an increase of TEA concentration in the range of low concentration, the increase of activity might be attributed to the progressive activation of potential catalytic sites by interaction with TEA. 26 The decrease of the overall rate or increase of the decay rate for larger TEA concentration beyond certain limits might be due to the overreduction of titan i~m .~~…”

Polymerization of olefins through heterogeneous catalysis. II. Kinetics of gas phase propylene polymerization with Ziegler–Natta catalysts

“…To observe the rate decay phenomenon, we carried out an interruption experiment similar to that performed by Doi et al 23 As shown in Figure 17, propylene was replaced by nitrogen during the polymerization, and, after about an hour of intermission, propylene was reintroduced to resume polymerization. Note that the rate decay seems to continue during the Note that the first-order decay law fits the reaction rate data very well and that the decay constant is not very sensitive to the [Al]/[Ti] ratio.…”