Abstract: Provided are blends of branched hydrocarbon comb polymers having tailored branching and molecular weight parameters, with substantially linear polymers. Such blends have been found to have improved extensional rheological properties, while maintaining nearly the viscosity of the substantially linear polymers. The blends of the hydrocarbon comb polymers with the substantially linear polymers thus maintain the extrusion processing characteristics of the linear polymer alone, but have improved extensional flow processability, with strain hardening ratios (SHR) greater than 1. The blends are effective in blown film processing. Also disclosed are related methods for improving extensional flow processability using the branched hydrocarbon comb polymers, as well as the branched hydrocarbon comb polymers themselves, including as a property enhancing additive for such substantially linear polymers.

Abstract: Provided are blends of branched hydrocarbon comb polymers having tailored branching and molecular weight parameters, with substantially linear polymers. Such blends have been found to have improved extensional rheological properties, while maintaining nearly the viscosity of the substantially linear polymers. The blends of the hydrocarbon comb polymers with the substantially linear polymers thus maintain the extrusion processing characteristics of the linear polymer alone, but have improved extensional flow processability, with strain hardening ratios (SHR) greater than 1. The blends are effective in blown film processing. Also disclosed are related methods for improving extensional flow processability using the branched hydrocarbon comb polymers, as well as the branched hydrocarbon comb polymers themselves, including as a property enhancing additive for such substantially linear polymers.

Abstract: A film comprising a polyethylene composition, the polyethylene composition in one embodiment comprising a high molecular weight component having a weight average molecular weight of greater than 50,000 amu and a low molecular weight component having a weight average molecular weight of less than 50,000 amu; the polyethylene composition possessing a density of between 0.940 and 0.970 g/cm3, and an I21 value of less than 20 dg/min; characterized in that the polyethylene composition extrudes at an advantageously high specific throughput at an advantageously low melt temperature, and wherein the film has a gel count of less than 100.

Abstract: A film comprising a polyethylene composition, the polyethylene composition in one embodiment comprising a high molecular weight component having a weight average molecular weight of greater than 50,000 amu and a low molecular weight component having a weight average molecular weight of less than 50,000 amu; the polyethylene composition possessing a density of between 0.940 and 0.970 g/cm3, and an I21 value of less than 20 dg/min; characterized in that the polyethylene composition extrudes at an advantageously high specific throughput at an advantageously low melt temperature, and wherein the film has a gel count of less than 100.

Abstract: A process of producing a bimodal polyolefin composition is described, which includes in one embodiment contacting monomers with a supported bimetallic catalyst composition for a time sufficient to form a bimodal polyolefin composition that includes a high molecular weight polyolefin component and a low molecular weight polyolefin component; wherein the supported bimetallic catalyst includes a first catalyst component that is preferably non-metallocene, and a second catalyst component that includes a metallocene catalyst compound having at least one fluoride or fluorine containing leaving group, wherein the bimetallic catalyst is supported by an enhanced silica, dehydrated at a temperature of 800° C. or more in one embodiment.

Abstract: A film comprising a polyethylene composition, the polyethylene composition in one embodiment comprising a high molecular weight component having a weight average molecular weight of greater than 50,000 amu and a low molecular weight component having a weight average molecular weight of less than 50,000 amu; the polyethylene composition possessing a density of between 0.940 and 0.970 g/cm3, and an I21 value of less than 20 dg/min; characterized in that the polyethylene composition extrudes at an advantageously high specific throughput at an advantageously low melt temperature, and wherein the film has a gel count of less than 100.

Abstract: A process of producing a bimodal polyolefin composition is described, which includes in one embodiment contacting monomers with a supported bimetallic catalyst composition for a time sufficient to form a bimodal polyolefin composition that includes a high molecular weight polyolefin component and a low molecular weight polyolefin component; wherein the supported bimetallic catalyst includes a first catalyst component that is preferably non-metallocene, and a second catalyst component that includes a metallocene catalyst compound having at least one fluoride or fluorine containing leaving group, wherein the bimetallic catalyst is supported by an enhanced silica, dehydrated at a temperature of 800° C. or more in one embodiment.

Abstract: A method of transitioning catalysts for polyolefin polymerization is provided. In one aspect, the process includes providing a polymerization reactor that includes a first catalyst system, contacting olefin monomers with the first catalyst system to form polyolefin in a first polymerization reaction and introducing a catalyst killer to the polymerization reactor in an amount sufficient to terminate the first polymerization reaction. The method further includes introducing a second catalyst system to the polymerization reactor in the presence of at least a portion of the catalyst killer, wherein the at least a portion of the catalyst killer is an amount sufficient to activate the second catalyst system and contacting olefin monomers with the second catalyst system to form polyolefin in a second polymerization reaction.

Abstract: A method of transitioning catalysts for polyolefin polymerization is provided. In one aspect, the process includes providing a polymerization reactor that includes a first catalyst system, contacting olefin monomers with the first catalyst system to form polyolefin in a first polymerization reaction and introducing a catalyst killer to the polymerization reactor in an amount sufficient to terminate the first polymerization reaction. The method further includes introducing a second catalyst system to the polymerization reactor in the presence of at least a portion of the catalyst killer, wherein the at least a portion of the catalyst killer is an amount sufficient to activate the second catalyst system and contacting olefin monomers with the second catalyst system to form polyolefin in a second polymerization reaction.

Abstract: A gas phase polymerization process for producing a polyolefin composition is described, which includes passing a gaseous stream containing hydrogen gas and one or more monomers, including ethylene monomers, through a reactor that includes a fluidized bed, under reactive conditions, in the presence of a catalyst that includes metallocene, to provide a polyolefin composition, wherein in one embodiment the fluidized bulk density is 60% or more of the settled bulk density (or, a voidage of 40% or less); and wherein the voidage is controlled by a number of factors including, in certain embodiments, (a) the reactor temperature being maintained at 100° C. or below; (b) the molar ratio of hydrogen gas to ethylene introduced into the reactor being 0.015 or below.

Abstract: A process of producing a bimodal polyolefin composition is described, which includes in one embodiment contacting monomers with a supported bimetallic catalyst composition for a time sufficient to form a bimodal polyolefin composition that includes a high molecular weight polyolefin component and a low molecular weight polyolefin component; wherein the supported bimetallic catalyst includes a first catalyst component that is preferably non-metallocene, and a second catalyst component that includes a metallocene catalyst compound having at least one fluoride or fluorine containing leaving group, wherein the bimetallic catalyst is supported by an enhanced silica, dehydrated at a temperature of 800° C. or more in one embodiment.

Abstract: A gas phase polymerization process for producing a polyolefin composition is described, which includes passing a gaseous stream containing hydrogen gas and one or more monomers, including ethylene monomers, through a reactor that includes a fluidized bed, under reactive conditions, in the presence of a catalyst that includes metallocene, to provide a polyolefin composition, wherein in one embodiment the fluidized bulk density is 60% or more of the settled bulk density (or, a voidage of 40% or less); and wherein the voidage is controlled by a number of factors including, in certain embodiments, (a) the reactor temperature being maintained at 100° C. or below; (b) the molar ratio of hydrogen gas to ethylene introduced into the reactor being 0.015 or below.

Abstract: The invention relates to alteration of a linear low density polyethylene which is ordinarily free of long chain branching to introduce long chain branching into the polymer.

Abstract: The invention relates to the production of high performance conduits. The invention includes the high performance conduits, the polyethylene resin used to make them, and the process for producing the resin which produces a resin with properties which are required, in accordance with the invention to yield the performance characteristics of the resin in conduits. The resin used in accordance with the invention exhibits a bimodal molecular weight distribution or broad molecular weight distribution and is of high molecular weight.

Abstract: A catalyst composition is described for preparing a high activity catalyst in silica which produces, in a single reactor, polyethylene with a broad or bimodal molecular weight distribution. The catalyst is prepared from the interaction of silica, previously calcined at 600.degree. C., with dibutylmagnesium, 1-butanol and titanium tetrachloride and a solution of methylalumoxane and ethylenebis[1-indenyl]zirconium dichloride.