A system and method of producing polyethylene, including: polymerizing ethylene in presence of a catalyst system in a reactor to form polyethylene, wherein the catalyst system includes a first catalyst and a second catalyst; and adjusting reactor conditions and an amount of the second catalyst fed to the reactor to control melt index (MI), density, and melt flow ratio (MFR) of the polyethylene.

This invention relates to a method comprising contacting C3-C32 alpha olefin with catalyst system comprising activator and catalyst of the formula wherein: M is Hf or Zr; T is a bridging group; each X is independently a leaving group; R1 and R2 are independently hydrogen, or a Ci-Gto optionally substituted hydrocarbyl group, halide, or siloxyl group; R3, R4, R5 and R6 are independently a Ci-Gto optionally substituted hydrocarbyl, halocarbyl, silylcarbyl, aminocarbyl, or siloxyl group; and A is an aliphatic, aromatic or heteroaromatic ring, optionally bearing one or more additional fused rings which may be aliphatic, aromatic or heteroaromatic; obtaining a plurality of vinyl-terminated polyalphaolefins (PAOs) having at least 30 mol % vinyl terminated PAO's.

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Provided are a metallocene supported catalyst capable of greatly reducing generation of fine powder during preparation of olefin polymers while exhibiting excellent catalyst activity, and a method of preparing olefin polymers using the same.

Metallocene complexes represented by the structure below are useful for alpha olefin oligomerization in the presence of an activator to generate polyalphaolefins having a high percentage of vinylidene termination and relatively low Mn values. ##STR00001##
M is a group 4 transition metal. A is a bridging group having one bridging atom extending between a first indenyl ring and a second indenyl ring. Each X is independently an anionic ligand, or two Xs are joined and bound to M to form a metallocycle ring, or two Xs are joined to form a chelating ligand, a diene ligand, or an alkylidene ligand. R.sup.1, R.sup.1′, R.sup.3, R.sup.3′, R.sup.4, R.sup.4′, R.sup.7 and R.sup.7′ are hydrogen. R.sup.5, R.sup.5′, R.sup.6, and R.sup.6′ are independently a C.sub.1-C.sub.10, optionally substituted, hydrocarbyl group, or R.sup.5 and R.sup.6 and/or R.sup.5′ and R.sup.6′ are bonded together to form an optionally substituted hydrocarbyl ring structure.

Catalyst systems and methods for making and using the same. A method of methylating a catalyst composition while substantially normalizing the entiomeric distribution is provided. The method includes slurrying the organometallic compound in dimethoxyethane (DME), and adding a solution of RMgBr in DME, wherein R is a methyl group or a benzyl group, and wherein the RMgBr is greater than about 2.3 equivalents relative to the organometallic compound. After the addition of the RMgBr, the slurry is mixed for at least about four hours. An alkylated organometallic is isolated, wherein the methylated species has a meso/rac ratio that is between about 0.9 and about 1.2.

The alkylation of transition metal coordination catalyst complexes (such as metallocenes and/or post-metallocenes) in non-polar solvents with high conversion to the dialkylated transition metal coordination catalyst complex may be accomplished by reacting (a) a transition metal coordination catalyst complex comprising a transition metal linked to at least one an anionic donor ligand and at least one leaving group having a non-carbon atom directly linked to the transition metal, (b) an aluminum alkyl, and (c) a fluoride salt at 0° C. to 85° C. in a non-polar solvent to yield an alkylated transition metal coordination catalyst complex.

Catalyst systems and methods for making and using the same. A method of polymerizing olefins to produce a polyolefin polymer with a multimodal composition distribution, includes contacting ethylene and a comonomer with a catalyst system. The catalyst system includes a first catalyst compound and a second catalyst compound that are co-supported to form a commonly supported catalyst system. The first catalyst compound includes a compound with the general formula (C.sub.5H.sub.aR.sup.1.sub.b)(C.sub.5H.sub.cR.sup.2.sub.d)HfX.sub.2. The second catalyst compound includes at least one of the following general formulas:

##STR00001##

##STR00002##

In both catalyst systems, the R groups can be independently selected from any number of substituents, including, for example, H, a hydrocarbyl group, a substituted hydrocarbyl group, or a heteroatom group, among others.

I, II, III and IV,

##STR00001## wherein Y is a C.sub.1-C.sub.20 linear, branched or cyclic hydrocarbyl group, or a C.sub.6-C.sub.30 aryl or substituted aryl group; L is an electron-donating ligand; A is an element selected from Group 15 or 16; R is a C.sub.1-C.sub.30 alkyl, aryl, or substituted aryl group; n is an integer from 1 to 3; m is an integer from 1 to 4; B is a boron atom; M is selected from lanthanides or transition metals from group 3, 4, 5 or 6; X is an anionic ligand to M and z is the valence of M minus 2; and a catalyst comprising a 2-indenyl metallocene complex, a ligand precursor, a process for preparation of a ligand precursor, a process for preparation of olefin polymers in the presence of 2-indenyl metallocene complexes, articles comprising an olefin polymer, and methods of making the articles.

Provided is a polyethylene. More particularly, provided is a polyethylene which has excellent abrasion resistance and thus is suitable for fiber production.

Catalyst systems and methods for making and using the same. A method of polymerizing olefins to produce a polyolefin polymer with a multimodal composition distribution, includes contacting ethylene and a comonomer with a catalyst system. The catalyst system includes a first catalyst compound and a second catalyst compound that are co-supported to form a commonly supported catalyst system. The first catalyst compound includes a compound with the general formula (C.sub.5H.sub.aR.sup.1.sub.b)(C.sub.5H.sub.cR.sup.2.sub.d)HfX.sub.2. The second catalyst compound comprises the following formula:

##STR00001##

wherein each R.sup.3 or R.sup.4 is independently H, a hydrocarbyl group, a substituted hydrocarbyl group, or a heteroatom group, wherein each R.sup.3 or R.sup.4 may be the same or different, and each X is independently a leaving group selected from a labile hydrocarbyl, a substituted hydrocarbyl, a heteroatom group, or a divalent radical that links to an R.sup.3 group.