Abstract:
Catalyst systems having both a metallocene catalyst component and a Ziegler-Natta component are disclosed. Such catalyst systems can contain a metallocene compound, an activator-support, an organoaluminum compound, and a Ziegler-Natta component comprising titanium supported on magnesium chloride.
Abstract:
A method of determining multimodal polyethylene quality comprising the steps of (a) providing a multimodal polyethylene resin sample; (b) determining, in any sequence, the following: that the multimodal polyethylene resin sample has a melt index within 30% of a target melt index; that the multimodal polyethylene resin sample has a density within 2.5% of a target density; that the multimodal polyethylene resin sample has a dynamic viscosity deviation (% MVD) from a target dynamic viscosity of less than about 100%; that the multimodal polyethylene resin sample has a weight average molecular weight (Mw) deviation (% MwD) from a target Mw of less than about 20%; and that the multimodal polyethylene resin sample has a gel permeation chromatography (GPC) curve profile deviation (% GPCD) from a target GPC curve profile of less than about 15%; and (c) responsive to step (b), designating the multimodal polyethylene resin sample as a high quality resin.
Abstract:
Disclosed herein are ethylene-based polymers generally characterized by a density from 0.89 to 0.93 g/cm3, a ratio of Mw/Mn from 3 to 6.5, a Mz from 200,000 to 650,000 g/mol, a CY-a parameter at 190° C. from 0.2 to 0.4, and a reverse short chain branching distribution. The ATREF profile of these polymers can have a high temperature peak from 92 to 102° C., and a low temperature peak from 18 to 36° C. less than that of the high temperature peak. These polymers can have comparable physical properties to that of a metallocene-catalyzed LLDPE, but with improved processability, shear thinning, and melt strength, and can be used in blown film and other end-use applications.
Abstract:
A method of preparing a polymer article comprising determining a zero-shear viscosity for a polymer sample; sieving the polymer sample to produce a plurality of sieved polymer samples; determining a molecular weight distribution for each of the plurality of sieved polymer samples; determining a zero-shear viscosity for each of the plurality of sieved polymer samples; determining a compositional diversity of each of the plurality of sieved polymer samples based on a ratio of the zero shear viscosity for each of the plurality of sieved polymer samples to the zero shear viscosity for the polymer sample; identifying a polymer sample having a ratio of the zero shear viscosity to zero shear viscosity for the polymer sample of from about 0.5 to equal to or greater than about 3; and preparing a polymer article from the identified polymer sample.
Abstract:
Catalyst systems having both a metallocene catalyst component and a Ziegler-Natta component are disclosed. Such catalyst systems can contain a metallocene compound, an activator-support, an organoaluminum compound, and a Ziegler-Natta component comprising titanium supported on magnesium chloride.
Abstract:
Disclosed herein are polymerization processes for the production of olefin polymers. These polymerization processes use a catalyst system containing three metallocene components, often resulting in polymers having a reverse comonomer distribution and a broad and non-bimodal molecular weight distribution.
Abstract:
Disclosed herein are polymerization processes for the production of olefin polymers. These polymerization processes can use a dual catalyst system containing a zirconium or hafnium based metallocene compound and a titanium based half-metallocene compound containing an indenyl group.
Abstract:
Disclosed herein are polymerization processes for the production of olefin polymers. These polymerization processes use a catalyst system containing three metallocene components, often resulting in polymers having a reverse comonomer distribution and a broad and non-bimodal molecular weight distribution.
Abstract:
Methods of controlling polymerization reactions using a synergistic amount of hydrogen and an organozinc compound are disclosed. The resulting polymers have lower molecular weights and higher melt flow indices.
Abstract:
Disclosed herein are polymerization processes for the production of olefin polymers. These polymerization processes can use a dual catalyst system containing a zirconium or hafnium based metallocene compound and a titanium based half-metallocene compound containing an indenyl group.