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.

Embodiments of polyethylene compositions and articles comprising polyethylene compositions are disclosed. The polyethylene compositions may include a first polyethylene fraction area defined by an area in the elution profile in a temperature range of 70° C. to 97° C. via improved comonomer composition distribution (iCCD) analysis method; a first peak in the temperature range of 70° C. to 97° C. in the elution profile; a second polyethylene fraction area defined by an area in the elution profile in a temperature range of 97° C. to 110° C.; and a second peak in the temperature range of 97° C. to 110° C. The polyethylene composition may have a density of 0.935 g/cm.sup.3 to 0.955 g/cm.sup.3 and a melt index (I.sub.2) of 1.0 g/10 minutes to 10.0 g/10 minutes. A ratio of the first polyethylene fraction area to the second polyethylene fraction area may be less than 2.0.

Embodiments of polyethylene compositions and articles comprising polyethylene compositions are disclosed. The polyethylene compositions may include a first polyethylene fraction area defined by an area in the elution profile in a temperature range of 70° C. to 97° C. via improved comonomer composition distribution (iCCD) analysis method; a first peak in the temperature range of 70° C. to 97° C. in the elution profile; a second polyethylene fraction area defined by an area in the elution profile in a temperature range of 97° C. to 110° C.; and a second peak in the temperature range of 97° C. to 110° C. The polyethylene composition may have a density of 0.935 g/cm.sup.3 to 0.955 g/cm.sup.3 and a melt index (I.sub.2) of 1.0 g/10 minutes to 10.0 g/10 minutes. A ratio of the first polyethylene fraction area to the second polyethylene fraction area may be less than 2.0.

Provided in this disclosure are zirconium and hafnium complexes that contain 1) a cyclopentadienyl ligand; 2) an adamantyl-phosphinimine ligand; and 3) at least one other ligand. The use of such a complex, in combination with an activator, as an olefin polymerization catalyst is demonstrated. The catalysts are effective for the copolymerization of ethylene with an alpha olefin (such as 1-butene, 1-hexene, or 1-octene).

Provided in this disclosure are zirconium and hafnium complexes that contain 1) a cyclopentadienyl ligand; 2) an adamantyl-phosphinimine ligand; and 3) at least one other ligand. The use of such a complex, in combination with an activator, as an olefin polymerization catalyst is demonstrated. The catalysts are effective for the copolymerization of ethylene with an alpha olefin (such as 1-butene, 1-hexene, or 1-octene).

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Embodiments of the present application are directed to procatalysts, and catalyst systems including procatalysts, including a metal-ligand complex having the structure of formula (I):

##STR00001##

Embodiments of the present application are directed to procatalysts, and catalyst systems including procatalysts, including a metal-ligand complex having the structure of formula (I):

Disclosed are a spherelike supermacroporous mesoporous material, a polyolefin catalyst, and a preparation method therefor and an olefin polymerization process. The spherelike supermacroporous mesoporous material has a twodimensional hexagonal ordered pore channel structures. The mesoporous material has an average pore size of 10 nm to 15 nm, a specific surface area of 300 m.sup.2/g to 400 m.sup.2/g, and an average particle size of 1 .Math.m to 3 .Math.m, based on the total mass of the mesoporous material. The mass content of water in the mesoporous material is < 1 ppm. The mass content of oxygen in the mesoporous material is < 1 ppm. When a polyolefin catalyst prepared with the mesoporous material as a carrier is used for an olefin polymerization reaction, the a polyolefin product with a narrow molecular weight distribution and a good melt index can be obtained.

Disclosed are a spherelike supermacroporous mesoporous material, a polyolefin catalyst, and a preparation method therefor and an olefin polymerization process. The spherelike supermacroporous mesoporous material has a twodimensional hexagonal ordered pore channel structures. The mesoporous material has an average pore size of 10 nm to 15 nm, a specific surface area of 300 m.sup.2/g to 400 m.sup.2/g, and an average particle size of 1 .Math.m to 3 .Math.m, based on the total mass of the mesoporous material. The mass content of water in the mesoporous material is < 1 ppm. The mass content of oxygen in the mesoporous material is < 1 ppm. When a polyolefin catalyst prepared with the mesoporous material as a carrier is used for an olefin polymerization reaction, the a polyolefin product with a narrow molecular weight distribution and a good melt index can be obtained.

This disclosure relates to ethylene interpolymer product having intermediate branching. Intermediate branching was defined as branching that was longer than the branch length due to comonomer and shorter than the entanglement molecular weight (M.sub.e). Intermediately branched ethylene interpolymer products were produced in a continuous solution polymerization process employing an intermediate branching catalyst formulation. Intermediately branched ethylene interpolymer products were characterized by a Non-Comonomer Index Distribution (NCID.sub.i), a melt index from 0.3 to 500 dg/minute, a density from 0.858 to 0.965 g/cm.sup.3, a polydispersity (M.sub.w/M.sub.n) from about 2 to about 25 and a CDBI.sub.50 from about 10% to about 98%. A method based on triple detection cross fractionation chromatography (3D-CFC) was disclosed to measure NCID.sub.i.