Abstract: A composition comprising a polyethylene wherein the composition is enriched in polymer molecules having topological variations by an enrichment factor ? and wherein the composition displays a long chain branching frequency of greater than about 0.5 long chain branches per 1000 total carbon atoms. A composition comprising an isolated Ziegler-catalyzed polyethylene having a long chain branching frequency of greater than about 0.5 long chain branches per 1000 total carbon atoms at the high molecular weight end.

Abstract: A catalyst composition comprising (a) a first metallocene complex represented by the general formula: where M1 is Ti, Zr or Hf, X1 and X2 are each independently F, Cl, Br, I, methyl, benzyl, phenyl, H, BH4, a hydrocarbyloxide group having up to 20 carbon atoms, a hydrocarbylamino group having up to 20 carbon atoms, a trihydrocarbylsilyl group having up to 20 carbon atoms, OBR?2 wherein R? may be an alkyl group having up to 12 carbon atoms or an aryl group having up to 12 carbon atoms, and SO3R? wherein R? may be an alkyl group having up to 12 carbon atoms or an aryl group having up to 12 carbon atoms, and Cp1 and Cp2 are each independently a substituted or unsubstituted cyclopentadienyl group, or a substituted or unsubstituted indenyl group, where any substituent on Cp1 and Cp2 is H, a hydrocarbyl group having up to 18 carbon atoms or a hydrocarbylsilyl group having up to 18 carbon atoms, (b) a second metallocene complex, (c) a non-group 4 metallocene transition-metal complex, (d) an activator or activato

Abstract: A method of preparing a medium-density polyethylene pipe comprising melting a multimodal metallocene-catalyzed polyethylene resin to form a molten polyethylene, wherein the multimodal metallocene-catalyzed polyethylene resin has a density of from about 0.925 g/ml to about 0.942 g/ml, a magnitude of slip-stick greater than about 300 psi, a stress for smooth to matte transition of greater than about 90 kPa of stress, and a shear rate for smooth to matte transition greater than about 10 s?1, wherein the magnitude of slip-stick, stress for smooth to matte transition, and shear rate for smooth to matte transition are determined by a capillary rheology test; and forming the molten polyethylene resin into pipe. A pipe prepared from a multimodal metallocene-catalyzed polyethylene resin having a density of from about 0.925 g/ml to about 0.

Abstract: The present techniques relate to catalyst compositions, methods, and polymers encompassing a Group 4 metallocene compound comprising bridging ?5-cyclopentadienyl-type ligands, typically in combination with a cocatalyst, and a activator. The compositions and methods presented herein include ethylene polymers with low melt elasticity.

Abstract: A method of preparing a medium-density polyethylene pipe comprising melting a multimodal metallocene-catalyzed polyethylene resin to form a molten polyethylene, wherein the multimodal metallocene-catalyzed polyethylene resin has a density of from about 0.925 g/ml to about 0.942 g/ml, a magnitude of slip-stick greater than about 300 psi, a stress for smooth to matte transition of greater than about 90 kPa of stress, and a shear rate for smooth to matte transition greater than about 10 s?1, wherein the magnitude of slip-stick, stress for smooth to matte transition, and shear rate for smooth to matte transition are determined by a capillary rheology test; and forming the molten polyethylene resin into pipe. A pipe prepared from a multimodal metallocene-catalyzed polyethylene resin having a density of from about 0.925 g/ml to about 0.

Abstract: A method of improving processing of polyethylene resins comprising obtaining a plurality of multimodal metallocene-catalyzed polyethylene samples measuring the shear stress as a function of shear rate for the plurality of multimodal metallocene-catalyzed polyethylene samples using capillary rheometry wherein the measuring yields values for a magnitude of slip-stick, a stress for smooth to matte transition, and a shear rate for smooth to matte transition; and identifying from the plurality of multimodal metallocene-catalyzed polyethylene samples individual multimodal metallocene-catalyzed polyethylene resins having a reduced tendency to melt fracture characterized by a magnitude of slip-stick greater than about 300 psi, a stress for smooth to matte transition greater than about 90 kPa, and a shear rate for smooth to matte transition greater than about 10 s?1.

Abstract: A system for improving processing of polyethylene resins, comprising a processor; a memory; an output device; and an analysis component stored in the memory, that when executed on the processor, configures the processor to receive a shear stress as a function of shear rate for a plurality of multimodal metallocene-catalyzed polyethylene samples, wherein the determination of the shear stress as a function of the shear rate comprises using capillary rheometry; determine values for a magnitude of slip-stick, a stress for smooth to matte transition, and a shear rate for smooth to matte transition for each of the plurality of multimodal metallocene-catalyzed polyethylene samples based on the shear stress and the shear rate measured from capillary rheometry; identify individual multimodal metallocene-catalyzed polyethylene resins from the plurality of multimodal metallocene-catalyzed polyethylene samples having a reduced tendency to melt fracture characterized by a magnitude of slip-stick greater than about 300 psi

Abstract: The present techniques relate to catalyst compositions, methods, and polymers encompassing a Group 4 metallocene compound comprising bridging ?5-cyclopentadienyl-type ligands, typically in combination with a cocatalyst, and a activator. The compositions and methods presented herein include ethylene polymers with low melt elasticity.

Abstract: The present invention provides a polymerization process which is conducted by contacting an olefin monomer and at least one olefin comonomer in the presence of hydrogen and a metallocene-based catalyst composition. Polymers produced from the polymerization process are also provided, and these polymers have a reverse comonomer distribution, low levels of long chain branches, and a ratio of Mw/Mn from about 3 to about 6.

Abstract: The present techniques relate to catalyst compositions, methods, and polymers encompassing a Group 4 metallocene compound comprising bridging ?5-cyclopentadienyl-type ligands, typically in combination with a cocatalyst, and a activator. The compositions and methods presented herein include ethylene polymers with low melt elasticity.

Abstract: A composition comprising a polyethylene wherein the composition is enriched in polymer molecules having topological variations by an enrichment factor ? and wherein the composition displays a long chain branching frequency of greater than about 0.5 long chain branches per 1000 total carbon atoms. A composition comprising an isolated Ziegler-catalyzed polyethylene having a long chain branching frequency of greater than about 0.5 long chain branches per 1000 total carbon atoms at the high molecular weight end.

Abstract: The present invention provides a polymerization process which is conducted by contacting an olefin monomer and at least one olefin comonomer in the presence of hydrogen and a metallocene-based catalyst composition. Polymers produced from the polymerization process are also provided, and these polymers have a reverse comonomer distribution, low levels of long chain branches, and a ratio of Mw/Mn from about 3 to about 6.

Abstract: The present techniques relate to catalyst compositions, methods, and polymers encompassing a Group 4 metallocene compound comprising bridging ?5-cyclopentadienyl-type ligands, typically in combination with a cocatalyst, and a activator. The compositions and methods presented herein include ethylene polymers with low melt elasticity.

Abstract: A catalyst composition comprising (a) a first metallocene complex represented by the general formula: where M1 is Ti, Zr or Hf, X1 and X2 are each independently F, Cl, Br, I, methyl, benzyl, phenyl, H, BH4, a hydrocarbyloxide group having up to 20 carbon atoms, a hydrocarbylamino group having up to 20 carbon atoms, a trihydrocarbylsilyl group having up to 20 carbon atoms, OBR?2 wherein R? may be an alkyl group having up to 12 carbon atoms or an aryl group having up to 12 carbon atoms, and SO3R? wherein R? may be an alkyl group having up to 12 carbon atoms or an aryl group having up to 12 carbon atoms, and Cp1 and Cp2 are each independently a substituted or unsubstituted cyclopentadienyl group, or a substituted or unsubstituted indenyl group, where any substituent on Cp1 and Cp2 is H, a hydrocarbyl group having up to 18 carbon atoms or a hydrocarbylsilyl group having up to 18 carbon atoms, (b) a second metallocene complex, (c) a non-group 4 metallocene transition-metal complex, (d) an activator or activato

Abstract: The present techniques relate to catalyst compositions, methods, and polymers encompassing a Group 4 metallocene compound comprising bridging ?5-cyclopentadienyl-type ligands, typically in combination with a cocatalyst, and a activator. The compositions and methods presented herein include ethylene polymers with low melt elasticity.

Abstract: The present invention provides a polymerization process which is conducted by contacting an olefin monomer and at least one olefin comonomer in the presence of hydrogen and a metallocene-based catalyst composition. Polymers produced from the polymerization process are also provided, and these polymers have a reverse comonomer distribution, low levels of long chain branches, and a ratio of Mw/Mn from about 3 to about 6.

Abstract: The present invention provides several methods of determining values of physical or chemical properties of polymers. In these methods, at least two polymer training samples are provided. Characteristics of the polymer microstructures of the training samples are correlated with values of physical or chemical properties of the training samples. These correlations are subsequently applied to the respective characteristics of polymer test samples in order to determine the values of physical or chemical properties of the test samples.

Abstract: Systems and methods for predicting or calculating a virtual polymer property that is related to polymer architecture of a semi-crystalline polymer or calculating various virtual polymer properties related to polymer architecture as a means to design resins for particular end-use applications that require various mechanical and physical properties.

Abstract: The present invention provides several methods of determining values of physical or chemical properties of polymers. In these methods, at least two polymer training samples are provided. Characteristics of the polymer microstructures of the training samples are correlated with values of physical or chemical properties of the training samples. These correlations are subsequently applied to the respective characteristics of polymer test samples in order to determine the values of physical or chemical properties of the test samples.

Abstract: The present invention is directed to PE-100 ethylene copolymers and pipe made thereof having a Tabor abrasion between about 0.01 and about 0.001 grams lost/1000 revolutions. These copolymers are formed by contacting ethylene with at least one mono-1-olefin comonomer having from 2 to about 10 carbon atoms per molecule in a reaction zone under polymerization conditions in the presence of a hydrocarbon diluent, a catalyst system, and a cocatalyst. Additionally, the comonomers may be selected from mono-1-olefins having 4 to 10 carbon atoms, such as, 1-hexene, 1-butene, 4-methyl-1-pentene, 1-octene, and 1-decene. Further, these ethylene copolymers may be employed to produce PE-100 pipe having both small diameters and diameters in excess of 42 inches substantially without sagging or other gravitational deformation. Copolymers of ethylene and 1-hexene are disclosed which are used to produce PE-100 pipe.