Abstract:
Polymers, and systems and methods for making and using the same are described herein. A polymer includes ethylene and at least one alpha olefin having from 4 to 20 carbon atoms. The polymer has a melt index ratio (MIR) greater than about 40. The polymer also has a value for Mw1/Mw2 of at least about 2.0, wherein Mw1/Mw2 is a ratio of a weight average molecular weight (Mw) for a first half of a temperature rising elution (TREF) curve from a cross-fractionation (CFC) analysis to an Mw for a second half of the TREF curve. The polymer also has a value for Tw1 - Tw2 of less than about -15 °C, wherein Tw1 - Tw2 is a difference of a weight average elution temperature (Tw) for the first half of the TREF curve to a Tw for the second half of the TREF curve.
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 R 1 is a C 1 to C 20 alkyl, aryl or aralkyl group, wherein R 2 is an C 1 to C 20 alkyl, aryl or aralkyl group, and where R 3 is a C 1 to C 20 alkyl or a hydrogen, and where each X is independently a halide, C 1 to C 20 alkyl, aralkyl group or hydrogen.
Abstract:
Polymers, and systems and methods for making and using the same are described herein. A polymer includes ethylene and at least one alpha olefin having from 4 to 20 carbon atoms. The polymer is formed by a trimmed catalyst system including a supported catalyst including bis(n-propylcyclopentadienyl) hafnium (R 1 )(R 2 ) and a trim catalyst comprising meso-O(SiMe 2 lnd) 2 Zr 2 (R 1 )(R 2 ), wherein R 1 and R 2 are each, independently, methyl, chloro, fluoro, or a hydrocarbyl group.
Abstract:
Catalyst systems and methods for making and using the same are described. A method includes selecting a catalyst blend using a blend polydispersity index (bPDI) map. The polydispersity map is generated by generating a number of polymers for at least two catalysts. Each polymer is generated at a different hydrogen to ethylene ratio. At least one catalyst generates a higher molecular weight polymer and another catalyst generates a lower molecular weight polymer. A molecular weight for each polymer is measured. The relationship between the molecular weight of the polymers generated by each of the catalysts and the ratio of hydrogen to ethylene is determined. A family of bPDI curves for polymers that would be made using a number of ratios of a blend of the at least two catalysts for each of a number of ratios of hydrogen to ethylene. A ratio for the catalyst blend of the catalysts that generates a polymer having a bPDI that matches a polymer fabrication process is selected, and the product specific polyolefin is made using the catalyst blend.
Abstract:
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.
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 R 1 is a C 1 to C 20 alkyl, aryl or aralkyl group, wherein R 2 is an C 1 to C 20 alkyl, aryl or aralkyl group, and where R 3 is a C 1 to C 20 alkyl or a hydrogen, and where each X is independently a halide, C 1 to C 20 alkyl, aralkyl group or hydrogen.
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 R 1 and R 2 are each independently, phenyl, methyl, chloro, fluoro, or a hydrocarbyl group.