Polymerization with heterogeneous metalorganic catalysts. VI. Differences in polymerization activity of α‐olefins and some kinetic results on butene‐1 polymerization

Abstract

Relative changes in polymerization activity of ethylene, propylene, and butene‐1 in Ziegler‐Natta polymerization were compared by use of TiCl3 samples contaminated with O2 and H2O to various extents. Catalyst depletion varied for the three monomers which supported the existence of different active centers. In butene‐1 polymerizations with the system Al(C2H5)2Cl–TiCl3, the formation of active centers involves an irreversible and a reversible (adsorption) reaction, the former pertaining to the formation of Al(C2H5)Cl2 and dependent upon the purity of the TiCl3. The kinetic treatment of the rate curves suggests a mixed order of catalyst deactivation and again points to the importance of Al(C2H5)Cl2.

Impact of Process Poisons on the Performance of Post‐Phthalate Supported Ziegler–Natta Catalysts in Gas Phase Propylene Polymerization

“…The reactions of oxygen with alkyl aluminums have been investigated in many references where most of these studies were conducted on the first generation catalysts. [ 12–14 ] Oxygen is believed to react with the alkyl aluminum as follows: $$$$\begin{equation} {\mathrm{O}}_{2}+\mathrm{Al}{\mathrm{R}}_{3}\stackrel{\mathrm{yields}}{\to}{\mathrm{R}}_{2}\mathrm{AlOOR} \end{equation}$$$$…”

“…[ 15 ] More reactions with the different crystalline forms of TiCl 3 (first and second generation catalysts) have been proposed with varying positive and negative effects on catalyst activity depending on the form of TiCl 3 and the co‐catalyst used. [ 12–15 ]…”

“…[15] More reactions with the different crystalline forms of TiCl 3 (first and second generation catalysts) have been proposed with varying positive and negative effects on catalyst activity depending on the form of TiCl 3 and the co-catalyst used. [12][13][14][15] Reactions of alcohols and carbon oxides have been investigated extensively on the early generations of Ziegler-Natta catalysts within the contexts of counting active centers. [16][17][18][19] Carbon dioxide interaction with the catalyst is believed to be a selective adsorption on the formed active centers which is reversible in nature.…”

“…The reactions of oxygen with alkyl aluminums have been investigated in many references where most of these studies were conducted on the first generation catalysts. [12][13][14] Oxygen is believed to react with the alkyl aluminum as follows:…”

Effect of oxygen on Et2AlCl‐TiCl3 catalyst for propylene polymerization

“…Natta et al5 investigated the polymerization of propylene using EtAl(OEt)CI-TiCls catalyst and assumed that EtAl(0Et)CI reacts with AlCls contained as solid solution in Tic13 of AA grade to form EtZAIC1 [Eq. (2)] and that this Et2AlCI acts as an activator for TiCls. 2EtAI(OEt)CI + AlCls + Et2AIC1+ 2Al(OEt)C12 (2) However, the catalyst activity at O/Al = 1 is considerably higher as compared with the EtzAlC1-TiCb catalyst in Figure 1; consequently, it is difficult to explain this result by the assumption of Natta et al It is known that EtAI(0Et)CI is formed by the reaction between Et2AIC1 and ethanoL6 Consequently, the same effect should be obtained if ethanol is used in place of oxygen.…”