Embodiments are directed to catalyst systems comprising: a procatalyst; and a co-catalyst dissolved in a non-halogenated aprotic hydrocarbon solvent, the co-catalyst comprising: a non-coordinating borate dianion having the formula: (III) and two cations, each cation being independently chosen from a cation according to formula (I) or formula (II).

A method for preparing polymer includes the steps of enabling olefin and unsaturated carboxylate be subjected to a polymerization reaction in the presence of a catalyst to generate an olefin-unsaturated carboxylate polymer. The catalyst has a primary catalyst and optionally a cocatalyst. The primary catalyst has at least one complex represented by formula I, formula I, or formula I. By selecting a reacted unsaturated carboxylate monomer, catalysts, and a suitable polymerization process, a spherical and/or sphere-like polymer having good shape is directly prepared without subsequent processing steps such as granulation, and the obtained polymer product is not prone to fouling in a reactor and is convenient for transportation.

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Methods for determining the concentration of transition metal compounds in a solution containing more than one transition metal compound are described. Polymerization reactor systems providing real-time monitoring and control of the concentrations of the transition metal components of a multicomponent catalyst system are disclosed, as well as methods for operating such polymerization reactor systems and for improving methods of preparing the multicomponent catalyst system.

Methods of preparing a polymerization catalyst component is provided, in which a magnesium component, a Lewis acid solubilizing component, a titanium compound, optionally a transition metal compound different than the titanium compound, and typically an inert filler are combined in a slurrying agent and spray-dried to produce a catalyst precursor in the form of a substantially spherical and porous solid particle. The methods and catalysts of this disclosure can provide ethylene homopolymer and copolymer resins having a high molecular weight tail and a broadened molecular weight distribution as compared to more traditional Ziegler-Natta catalysts.

Disclosed herein are methods for synthesizing low valence, titanium-aluminum complexes from half-metallocene titanium compounds and alkylaluminum compounds. The titanium-aluminum complexes can be used as components in catalyst systems for the polymerization of olefins.

A process may include contacting ethylene monomer with Ziegler-Natta catalyst to form polyethylene. The Ziegler-Natta catalyst may be formed by contacting an alkyl magnesium compound with an alcohol and a metal reagent to form a blend, and contacting the blend with a first agent to form a solution of reaction product A. The solution of reaction product A may be contacted with a second agent to form a solid reaction product B, and the solid reaction product B may be contacted with a third agent to form a solid reaction product C. The solid reaction product C may be contacted with a fourth agent to form a solid reaction product D, and the solid reaction product D may be contacted with a fifth agent to form a catalyst component.

Compositions and methods for selective olefin (e.g., ethylene) polymerization comprising metal organic frameworks (MOFs) are generally provided. In some embodiments, a MOF comprises a plurality of metal ions, each coordinated with at least one ligand comprising at least two unsaturated N-heterocyclic aromatic groups arranged about an organic core.

The present invention provides a spherical supported transition metal catalyst. The catalyst carrier is a spherical titanium/zirconium hydrophosphate compound, the primary catalyst is a transition metal compound, the co-catalyst is methylaluminoxane; the spherical titanium/zirconium hydrophosphate compound comprises one or several combinations of titanium hydrophosphate, modified titanium hydrophosphate and zirconium hydrophosphate. The present invention also provides a preparation method of said spherical supported transition metal catalyst and a use thereof in olefin polymerization, as well as the spherical titanium/zirconium hydrophosphate compound and its preparation method. The spherical, supported transition metal catalyst in the present invention has a high catalytic activity, and the polymer particles obtained have good morphology.

The present invention relates to a catalyst composition including a transition metal compound represented by the following Formula 1; and one or more of a compound represented by the following Formula 2, a compound represented by the following Formula 3 and a compound represented by the following Formula 4. The catalyst composition according to the present invention has excellent copolymerization properties, and can be usefully used as a catalyst for a polymerization reaction for preparing an olefin-based polymer having a high molecular weight.

A catalyst component for olefin polymerization includes magnesium, titanium, a halogen, an internal electron donor compound, and a precipitation aid. The precipitation aid includes a precipitation aid represented by general formula (I). The precipitation aid represented by general formula (I) includes isomers represented by general formula (I-a) and/or (I-b). ##STR00001##