Abstract: A low density polyethylene composition characterized by having a density in range of 0.91 to 0.94 gm/cm3, a melt index in the range of 1 to 5 g/10 minutes, a gel permeation chromatography branching index in the range of 1.2 to 1, a polydispersity index in the range of 3.5 to 7.5, a viscosity ratio in the range of 0.7 to 1, and a long chain branching frequency greater than zero at a log molecular weight (log(MW)) value in the range of 4 to 5.5. Film formed from the polyethylene compositions with favorable haze and gloss characteristics, and a process for forming such film, are also described.

Abstract: The present disclosure provides a peroxide-modified polyethylene and related compositions as well as films, sheets, and multilayer structures made therefrom. A film composition is made from or containing a peroxide-modified polyethylene composition made from or containing a peroxide-modified polyethylene made from or containing the reaction products of a polyethylene composition made from or containing a first Ziegler-Natta-catalyzed polyethylene and a first amount of an organic peroxide to the second reactor.

Abstract: A low density polyethylene composition characterized by having a density in range of 0.91 to 0.94 gm/cm3, a melt index in the range of 1 to 5 g/10 minutes, a gel permeation chromatography branching index in the range of 1.2 to 1, a polydispersity index in the range of 3.5 to 7.5, a viscosity ratio in the range of 0.7 to 1, and a long chain branching frequency greater than zero at a log molecular weight (log(MW)) value in the range of 4 to 5.5. Film formed from the polyethylene compositions with favorable haze and gloss characteristics, and a process for forming such film, are also described.

Abstract: The present disclosure provides a peroxide-modified polyethylene and related compositions as well as films, sheets, and multilayer structures made therefrom. A film composition is made from or containing a peroxide-modified polyethylene composition made from or containing a peroxide-modified polyethylene made from or containing the reaction products of a polyethylene composition made from or containing a first Ziegler-Natta-catalyzed polyethylene and a first amount of an organic peroxide to the second reactor.

Abstract: Disclosed is a method for improving the barrier properties of polyethylene films. The method comprises mixing a substantially linear, high density polyethylene with a nucleating agent and converting the mixture into a film. The film made by the method of the invention has at least a 15% improvement on the water vapor barrier property and/or in the oxygen barrier property compared with the control film made from the same substantially linear, high density polyethylene but does not contain the nucleating agent.

Abstract: Disclosed are polyethylene blends and films. The blend comprises from 1 to 99%, based on the weight of the blend, of a medium density polyethylene (MDPE) and from 1 to 99% a polyolefin selected from the group consisting of high density polyethylene (HDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), polypropylene, polybutene, and mixtures thereof. The MDPE is made by high pressure, free radical polymerization and has a density within the range of greater than 0.928 to 0.940 g/cm3 and an MI2 within the range of 0.1 to 1 dg/min. The shrink films made from the blend have strong contraction force and low creep.

Abstract: Disclosed is a method for improving the barrier properties of polyethylene films The method comprises mixing a substantially linear, high density polyethylene with a nucleating agent and converting the mixture into a film The film made by the method of the invention has at least a 15% improvement on the water vapor barrier property and/or in the oxygen barrier property compared with the control film made from the same substantially linear, high density polyethylene but does not contain the nucleating agent.

Abstract: Disclosed is a method for improving the barrier properties of polyethylene films. The method comprises mixing a substantially linear, high density polyethylene with a nucleating agent and converting the mixture into a film. The film made by the method of the invention has at least a 15% improvement on the water vapor barrier property and/or in the oxygen barrier property compared with the control film made from the same substantially linear, high density polyethylene but does not contain the nucleating agent.

Abstract: Disclosed are polyethylene blends and films. The blend comprises from 1 to 99%, based on the weight of the blend, of a medium density polyethylene (MDPE) and from 1 to 99% a polyolefin selected from the group consisting of high density polyethylene (HDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), polypropylene, polybutene, and mixtures thereof. The MDPE is made by high pressure, free radical polymerization and has a density within the range of greater than 0.928 to 0.940 g/cm3 and an MI2 within the range of 0.1 to 1 dg/min. The shrink films made from the blend have strong contraction force and low creep.

Abstract: A polyolefin composition is disclosed. The composition comprises a single-site linear low density polyethylene (mLLDPE) and an elastoplastic polypropylene. The elastoplastic polypropylene is present in an amount sufficient to improve the processability and physical property of the mLLDPE. The composition preferably comprises from 70 wt % to 99 wt % of mLLDPE and from 1 wt % to 30 wt % of the elastoplastic polypropylene. The polyolefin composition of the invention exhibits improved bubble stability in the blown film extrusion compared to the mLLDPE and improved film properties such as tear strength and modulus compared to the traditional blend of mLLDPE and low density polyethylene.

Abstract: A two-stage cascade polymerization process for the production of multimodal polyethylene film resins with improved bubble stability is provided. The process comprises polymerizing ethylene or a mixture of ethylene and a C4-8 ?-olefin in two reactors arranged in series using a mixed single-site catalyst comprised of a bridged and a non-bridged indenoindolyl transition metal complex to form a multimodal polyethylene resin comprised of a lower molecular weight, higher density component and a higher molecular weight, lower density component.

Abstract: A thick film and process to prepare polyethylene useful for the film are disclosed. Ethylene is polymerized in two reaction zones with a C6-C10 ?-olefin in the presence of a catalyst system comprising an activator, a supported bridged zirconium complex, and a supported non-bridged zirconium complex. The process yields medium density to linear low density polyethylene having a melt index from 0.20 to 1.0 dg/min. Thick films from the polyethylene have a superior combination of high impact strength and high modulus.

Abstract: A thick film and process to prepare polyethylene useful for the film are disclosed. Ethylene is polymerized in two reaction zones with a C6-C10 ?-olefin in the presence of a catalyst system comprising an activator, a supported bridged zirconium complex, and a supported non-bridged zirconium complex. The process yields medium density to linear low density polyethylene having a melt index from 0.20 to 1.0 dg/min. Thick films from the polyethylene have a superior combination of high impact strength and high modulus.

Abstract: A process for making polyethylene having an uncommon but valuable balance of broad molecular weight distribution and a low level of long-chain branching is disclosed. The process comprises polymerizing ethylene in a single reactor in the presence of an ?-olefin and a catalyst comprising an activator and a supported dialkylsilyl-bridged bis(indeno[1,2-b]indolyl)zirconium complex. The polyethylene, which has an Mw/Mn greater than 10 and a viscosity enhancement factor (VEF) of less than 2.5, is valuable for making blown films.

Abstract: A two-stage cascade polymerization process for the production of multimodal polyethylene film resins with improved bubble stability is provided. The process comprises polymerizing ethylene or a mixture of ethylene and a C4-8 ?-olefin in two reactors arranged in series using a mixed single-site catalyst comprised of a bridged and a non-bridged indenoindolyl transition metal complex to form a multimodal polyethylene resin comprised of a lower molecular weight, higher density component and a higher molecular weight, lower density component.

Abstract: A lubricating oil suitable for use in ?-olefin compressors and a high-pressure ethylene polymerization process is disclosed. The oil comprises a base fluid and a hindered C6-C30 alkyl 4-hydroxybenzoate. The hindered C6-C30 alkyl 4-hydroxybenzoate stabilizes the lubricating oil and does not interfere with the high-pressure ?-olefin polymerization.

Abstract: A process for making polyethylene having an uncommon but valuable balance of broad molecular weight distribution and a low level of long-chain branching is disclosed. The process comprises polymerizing ethylene in a single reactor in the presence of an ?-olefin and a catalyst comprising an activator and a supported dialkylsilyl-bridged bis(indeno[1,2-b]indolyl)zirconium complex. The polyethylene, which has an Mw/Mn greater than 10 and a viscosity enhancement factor (VEF) of less than 2.5, is valuable for making blown films.

Abstract: Disclosed is a method for improving the barrier properties of polyethylene films. The method comprises mixing a substantially linear, high density polyethylene with a nucleating agent and converting the mixture into a film. The film made by the method of the invention has at least a 15% improvement on the water vapor barrier property and/or in the oxygen barrier property compared with the control film made from the same substantially linear, high density polyethylene but does not contain the nucleating agent.

Abstract: A blend comprising a high molecular weight, medium density polyethylene (HMW, MDPE) and a linear low density polyethylene (LLDPE) is disclosed. The blend comprises from about 20 wt % to about 80 wt % of HMW MDPE. The HMW MDPE has a density from about 0.92 to about 0.944 g/cc, a melt index MI2 from about 0.01 to about 0.5 dg/min, and a melt flow ratio MFR from about 50 to about 300. The blend also comprises about 20 wt % to about 80 wt % of LLDPE. The LLDPE has a density within the range of about 0.90 to about 0.925 g/cc and an MI2 within the range of about 0.50 to about 50 dg/min. The blend provides films with significantly improved toughness and tear strength compared to MDPE or HDPE, and high modulus compared to LLDPE.

Abstract: Phillips' process high density polyethylene resin compositions having improved processing stability are obtained using a combination of stabilizers comprised of a hindered phenol and a phosphite compound having three cyclic phosphite moieties linked via a nitrogen atom. More specifically, the phosphite compound is 2, [[2,4,8,10-tetrakis(1,1-dimethylethyl)dibenzo[d,f][1,3,2]-dioxaphosphepin- 6-yl]oxy]-N,N-bis [2-[[2,4,8,10-tetrakis (1,1-dimethylethyl) dibenzo[d,f][1,3,2]dioxaphosphenpin-6-yl]oxy]-ethyl]ethanamine. With the HDPE compositions stabilized in accordance with the invention, it is possible to eliminate undesirable rapid changes in melt viscosity which can occur when Phillips' process HDPE resins are processed under conditions of high shear.