Abstract: The present disclosure provides for a system and method for producing a polyethylene polymer (PE) that includes measuring a melt flow index (MFI) of the PE, comparing the measured value of the MFI to a predetermined desired range for the MFI, changing a catalyst feed rate to the polymerization reactor based on the compared values of the MFI, where changes in the catalyst feed rate preemptively compensate for subsequent changes in an oxygen flow rate to the polymerization reactor that maintain a predetermined residence time and bring the MFI of the PE into the predetermined desired range for the MFI; and changing the oxygen flow rate to the polymerization reactor thereby maintaining both the predetermined residence time and bringing the MFI of the PE into the predetermined desired range for the MFI. The measuring and comparing steps are repeated to ensure the measured value of the MFI is within the predetermined desired range of the MFI at the predetermined residence time.

Abstract: Provided are various bimodal polyethylene, including but not limited to a bimodal polyethylene for a pipe having a density of from 0.9340 to 0.9470 gram/cubic centimeters (g/ccm), a melt index (12) of from 0.1 to 0.7 gram/10 minute, a melt flow ratio (121/12) of from 20 to 90. The bimodal polyethylene includes a high molecular weight polyethylene component and a low molecular weight polyethylene component which are a reaction product of a polymerization process performed in a single reactor and that employs a bimodal polymerization catalyst system. The bimodal polymerization catalyst system includes a bimodal catalyst system of bis(2-pentamethylphenylamido)ethyl)amine Zirconium dibenzyl and either (tetramethylcyclopentadienyl)(n-propylcyclopentadienyl)Zirconium dichloride or (tetramethylcyclopentadienyl)(n-propylcyclopentadienyl)zirconium dimethyl in a 3.

Abstract: A high density, high polydispersity polyethylene having improved properties, and a process of producing same.

Abstract: Novel polyethylene copolymers having a relatively high comonomer partitioning tendency are disclosed as are methods for their preparation. The comonomer partitioning tendency is the tendency for a copolymer to have comonomer in the higher molecular weight chains. Novel metrics for describing the comonomer partitioning tendency are also disclosed.

Abstract: Embodiments of the present disclosure directed towards polymerization catalysts having improved ethylene enchainment. As an example, the present disclosure provides a polymerization catalyst having improved ethylene enchainment, the polymerization catalyst comprising a zirconocene catalyst of Formula (I) where R1 is a C1 to C20 alkyl, aryl or aralkyl group, wherein R2 is an C1 to C20 alkyl, aryl or aralkyl group, and where R3 is a C1 to C20 alkyl or a hydrogen, and where each X is independently a halide, C1 to C20 alkyl, aralkyl group or hydrogen.

Abstract: Embodiments of the present disclosure directed towards bimodal polymerization catalysts. As an example, the present disclosure provides a bimodal polymerization catalyst system including a non-metallocene olefin polymerization catalyst and a zirconocene catalyst of Formula I: (Formula I) where each of R1, R2, and R4 are independently a C1 to C20 alkyl, aryl or aralkyl group or a hydrogen, where R3 is a C1 to C20 alkyl, aryl or aralkyl group, and where each X is independently a halide, C1 to C20 alkyl, aralkyl group or hydrogen.

Abstract: Catalyst systems and methods for making and using the same are disclosed. A catalyst composition is provided that includes a catalyst compound supported to form a supported catalyst system, the catalyst compound including: where each of R1, R2, R3, R4, R5, R6, R7 and X are as discussed herein.

Abstract: A system and method for charging a chromium-based catalyst to a mix vessel; introducing a reducing agent through an entrance arrangement into the mix vessel, and agitating a mixture of the chromium-based catalyst, the reducing agent, and a solvent in the mix vessel to promote contact of the reducing agent with the chromium-based catalyst to give a reduced chromium-based catalyst.

Abstract: Supported catalyst compositions, useful in olefin polymerization, and having improved flow properties are disclosed. The catalyst compositions may be characterized by low macro pore volume and high bulk density. Methods for preparing the catalyst compositions are also disclosed.

Abstract: Synthetic methods for the preparation of ligands and metal-ligand complexes are disclosed.

Abstract: Polymerization process control methods for making polyethylene are provided. The process control methods include performing a polymerization reaction in a polymerization reactor to produce the polyethylene, where ethylene, and optionally one or more comonomers, in the polymerization reaction is catalyzed by an electron donor-free Ziegler-Natta catalyst and an alkyl aluminum co-catalyst. A melt flow ratio (I21/I2) of the polyethylene removed from the polymerization reactor is measured and an amount of long chain branching (LCB) of the polyethylene from the polymerization reactor is controlled by adjusting a weight concentration of the alkyl aluminum co-catalyst present in the polymerization reactor.

Abstract: 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.

Abstract: Novel polyethylene copolymers having a relatively high comonomer partitioning tendency are disclosed as are methods for their preparation. The comonomer partitioning tendency is the tendency for a copolymer to have comonomer in the higher molecular weight chains. Novel metrics for describing the comonomer partitioning tendency are also disclosed.

Abstract: The present disclosure provides a method of measuring a percent solids content (PSC) of solids by mass in a slurry catalyst composition, where the solids include a catalyst. The method includes obtaining a first time domain (TD) 1H-nuclear magnetic resonance (NMR) spectrum using a time domain (TD)-NMR spectrometer and a test sample of the slurry catalyst composition from which a value of a voltage signal (a) that represents the slurry catalyst composition is determined. A second TD 1H-NMR spectrum using the TD NMR spectrometer is obtained for a neat sample of the suspension liquid for the solids of the slurry catalyst composition, where a value of a voltage signal (b) from the second TD 1H-NMR spectrum that represents the suspension liquid for the solids of the slurry catalyst composition is determined.

Abstract: Synthetic methods for the preparation of ligands and metal-ligand complexes are disclosed.

Abstract: Catalyst systems and methods for making and using the same are disclosed. A catalyst composition is provided that includes a catalyst compound supported to form a supported catalyst system, the catalyst compound including: where each of R1, R2, R3, R4, R5, R6, R7 and X are as discussed herein.

Abstract: Synthetic methods for the preparation of ligands and metal-ligand complexes are disclosed.

Abstract: Methods for olefin polymerization are described. The methods include a) forming a first polyolefin under a first set of polymerization conditions in the presence of a first catalyst composition and a first concentration of at least a first continuity additive composition, the first polyolefin composition having a target density, ?1, and a target Flow Index, FI1; and b) forming a second polyolefin composition under a second set of polymerization conditions in the presence of a second catalyst composition and a second concentration of a second continuity additive composition, the second polyolefin composition having a target density, ?2, and a target Flow Index, FI2; wherein the process is essentially free of providing a polymerization neutralizing composition between steps a) and b).

Abstract: Methods for extrusion of polyolefins (110) that utilize melt temperature to control molecular weight and also reduce gels. Disclosed herein is an example method for controlling polymer chain scission in an extrusion system (100), comprising: melting a polyolefin resin (110) in extruder (102) at a first melt temperature to form a first melt (112); passing the first melt (112) through a screen pack (106); forming the first melt 112) into a first polyolefin product (116, 118); melting additional polyolefin resin (110) of the same grade in the extruder (102) at a second melt temperature to form a second melt (112), wherein the second melt temperature differs from the first melt temperature by 5° C. or more to control chain scission in the extruder (102); passing the second melt (112) through the screen pack (106); and forming the second melt (112) into a second polyolefin product (116, 118).

Abstract: A system and method for charging a chromium-based catalyst to a mix vessel; introducing a reducing agent through an entrance arrangement into the mix vessel, and agitating a mixture of the chromium-based catalyst, the reducing agent, and a solvent in the mix vessel to promote contact of the reducing agent with the chromium-based catalyst to give a reduced chromium-based catalyst.