Abstract: Embodiments of the present disclosure are directed towards methods of adjusting melt index and/or density utilizing a metallocene complex represented by Formula (I): wherein each n-Pr is n-propyl, and each X is independently CH3, CI, Br, or F.

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: A film formed from a polyethylene copolymer using a reduced chromium oxide catalyst, ethylene monomers and a co-monomer selected from butene monomers or 1-hexene, where the polyethylene copolymer has a density in the range of from about 0.935 to about 0.950 g/cm3 and an I21/I5 in a range of about 18.0 to about 30.0. The film formed from the polyethylene copolymer has a dart drop impact (g/?m) that significantly greater as compared to a film of the polyethylene copolymer formed using a silyl chromate catalyst in place of the reduced chromium oxide catalyst. A method of making such films is also provided.

Abstract: 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 (C5HaR1b)(C5HcR2d)HfX2. The second catalyst compound includes at least one of the following general formulas: 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.

Abstract: A method including contacting a chromium-based catalyst with a reducing agent in a solvent to lower an oxidation state of at least some chromium in the chromium-based catalyst to give a reduced chromium-based catalyst, drying the reduced chromium-based catalyst at a temperature, and adjusting the temperature to affect the flow index response of the reduced chromium-based catalyst.

Abstract: Embodiments of the present disclosure are directed towards method for modifying a polymer flow index. As an example, a method for modifying a polymer flow index can include providing monomers to a polymerization reactor, providing a chromium catalyst to the polymerization reactor, and providing an active amount of a flow index modifier to the polymerization reactor, wherein the flow index modifier is selected from carbon dioxide, carbon monoxide, 2,4-hexadiene, and combinations thereof.

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: A polymerization catalyst system, a method of using the polymerization catalyst system, and a polymer produced with the catalyst system. The polymerization catalyst system has a non-metallocene catalyst and a metallocene catalyst. The metallocene catalyst has the formula: wherein R1 and R2 are each independently, phenyl, methyl, chloro, fluoro, or a hydrocarbyl group.

Abstract: Methods for producing polyolefin polymers may use a predictive melt index regression to estimate the melt index of the polyolefin during production based on the composition of the gas phase and, optionally, the concentration of catalyst in the reactor or reactor operating conditions. Such predictive melt index regression may include multiple terms to account for concentration of ICA in the reactor, optionally concentration of hydrogen in the reactor, optionally concentration of comonomer in the reactor, optionally the catalyst composition, and optionally reactor operating conditions. One or more terms may independently be represented by a smoothing function that incorporates a time constant.

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: A method including contacting a chromium-based catalyst with a reducing agent in a solvent to lower an oxidation state of at least some chromium in the chromium-based catalyst to give a reduced chromium-based catalyst, drying the reduced chromium-based catalyst at a temperature, and adjusting the temperature to affect the flow index response of the reduced chromium-based catalyst.

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

Abstract: Methods and systems for olefin polymerization are provided. The method for olefin polymerization can include flowing a catalyst through an injection nozzle and into a fluidized bed disposed within a reactor. The method can also include flowing a feed comprising one or more monomers, one or more inert fluids, or a combination thereof through the injection nozzle and into the fluidized bed. The feed can be at a temperature greater than ambient temperature. The method can also include contacting one or more olefins with the catalyst within the fluidized bed at conditions sufficient to produce a polyolefin.

Abstract: A method comprising synthesizing a cyclic organic compound (3) via reaction of an substituted alkene (1) with an unsubstituted or substituted acrylic acid (2) in the presence of a sulfonic acid reagent to make the cyclic organic compound (3) R1(II)C?C(H)R2 (I)

Abstract: A system and method for feeding a chromium-based catalyst to a polymerization reactor; adding a reducing agent to the chromium-based catalyst, and polymerizing an olefin into a polyolefin in the polymerization reactor in the presence of the chromium-based catalyst.

Abstract: Embodiments of the present disclosure are directed towards metal complexes that can be utilized to form polymers. As an example, the present disclosure provides a metal complex of Formula (I) wherein M is Zr, Hf, or Ti; each Het is independently a heterocyclic; each L is independently a bridging group; each X is independently Cl, Br, I, or alkyl; each R1 is independently selected from the group including hydrogen, alkyls, alkenyls, alkynyls, cycloalkyls, aryls, acyls, aroyls, alkoxys, aryloxys, alkylthiols, dialkylamines, alkylamidos, alkoxycarbonyls, aryloxycarbonyls, carbomoyls, alkyl- and dialkyl-carbamoyls, acyloxys, acylaminos, aroylaminos, aromatic rings, fused aromatic rings, and combinations thereof; and each n is independently an integer having a value of one to five.

Abstract: An improved method of characterizing the PSD of particles.

Abstract: Methods and systems for olefin polymerization are provided. The method for olefin polymerization can include flowing a catalyst through an injection nozzle and into a fluidized bed disposed within a reactor. The method can also include flowing a feed comprising one or more monomers, one or more inert fluids, or a combination thereof through the injection nozzle and into the fluidized bed. The feed can be at a temperature greater than ambient temperature. The method can also include contacting one or more olefins with the catalyst within the fluidized bed at conditions sufficient to produce a polyolefin.

Abstract: Disclosed are novel bis(aminophenylphenol) ligands and transition metal compounds derived therefrom. Also disclosed are methods of making the ligands and transition metal compounds.

Abstract: New methods for preparing bridged bi-aromatic ligands are disclosed. The methods employ aryl coupling of unprotected phenols. The ligands may be used to prepare transition metal compounds useful as catalysts in olefin polymerization.