Abstract:
Blown films and processes of forming the same are described herein. The processes generally include providing a bimodal ethylene based polymer, blending the bimodal ethylene based polymer with at least about 30 ppm peroxide to form modified polyethylene and forming the modified polyethylene into a blown film.
Abstract:
Fibers and methods of forming the fibers are described herein. The fibers generally include an ethylene based polymer exhibiting a molecular weight distribution of from about 2 to about 8.
Abstract:
This invention relates to high density polyethylene blown films having good barrier properties and improved processing characteristics. The method incorporates the use of peroxide which results in improved bubble stability without sacrifice in barrier properties. The polyethylenes have a density greater than about 0.950g/cc, are relatively narrow in molecular weight distribution MWD (in the range of from about 2.0 to about 6.5), and are of medium molecular weight. In an embodiment, the films also have a rheological breadth parameter, a, that has been reduced by at least about 5%, but not more than 45%, by addition of a peroxide to the polyethylene. The addition of peroxide improves processability without sacrificing strength and barrier properties such as oxygen transmission rate.
Abstract:
Disclosed is a bimodal Ziegler-Natta catalyzed polyethylene, having a density of from.930 g/cc to 0.960 g/cc, and a molecular weight distribution of from 10 to 25, wherein an article formed therefrom has a PENT of at least 1500. Also disclosed is a method of preparing a tubular article including obtaining a bimodal polyethylene having a density of from.930 g/cc to 0.960 g/cc and a molecular weight distribution of from 10 to 25, and processing the polyethylene under conditions where a specific energy input (SEI) is less than 300kW.h/ton, and wherein the article has a PENT of at least 1500. Further disclosed is a method for controlling the degradation of polyethylene including polymerizing ethylene monomer, recovering polyethylene, extruding the polyethylene, and controlling the degradation of polyethylene by measuring the SEI to the extruder and adjusting throughput and/or gear suction pressure keep SEI less than 300kW.h/ton, and forming an article.
Abstract:
It has been discovered that certain compounds serve as polymerization accelerators when employed together with peroxide initiators for the polymerization of vinylaromatic monomers. Suitable accelerators that increase the rate of decomposition of the peroxide initiator include, but are not necessarily limited to, hydroperoxides and/or metallic salts. Representative examples of suitable hydroperoxide accelerators include t-butyl hydroperoxide (TBH), cumyl hydroperoxide, and p-isopropyl cumyl hydroperoxide, whereas suitable metallic salt accelerators include cobalt naphthenate and cobalt acetoacetonate. Use of these accelerators when vinylaromatic monomers are polymerized in the presence of polybutadienes and peroxide initiators results in an increase in grafting as compared with similar copolymers made without the accelerator.
Abstract:
Blown films and processes of forming the same are described herein. The blown films generally include high density polyethylene exhibiting a molecular weight distribution of from about 1.5 to about 8.0 and a density of from 0.94 g/cc to less than 0.96 g/cc.
Abstract:
Disclosed are novel non-linear vinyl polymers comprised of a multifunctional peroxide, and a cross-linking agent and/or a chain transfer agent, and methods of making such polymers having: at least 0.03 branches/1000 backbone carbons; linear portions with a molecular weight (Mw) of 350,000 or less; 0.2 to 3.0 branches/molecule; or, a Mz/Mw of from 1.7 to 5.7. Methods of quantifying branching are disclosed using a linear reference having 0.0 to 0.06 branches/1000 backbone carbons along with SEC techniques and measurements of molecular weight, molecular size, and concentration. Also discovered is a vinyl polymer resin comprised of from 0.1 to 50 weight percent of non-linear polymers having at least 0.06 branches/1000 backbone carbons, where branching is measured using a heat polymerized polystyrene having from 0.0 to 0.06 branches/1000 backbone carbons as a linear reference.
Abstract:
Polymer articles and processes of forming the same are described herein. The processes generally include providing an ethylene based polymer, blending the ethylene based polymer with a modifier to form modified polyethylene and forming the modified polyethylene into a polymer article, wherein the polymer article exhibits a haze that is at least about 10% less than a polymer article prepared, with a similarly modified polyethylene.
Abstract:
Disclosed are novel non-linear vinyl polymers comprised of a multifunctional peroxide, and a cross-linking agent and/or a chain transfer agent, and methods of making such polymers having: at least 0.03 branches/1000 backbone carbons; linear portions with a molecular weight (Mw) of 350,000 or less; 0.2 to 3.0 branches/molecule; or, a Mz/Mw of from 1.7 to 5.7. Methods of quantifying branching are disclosed using a linear reference having 0.0 to 0.06 branches/1000 backbone carbons along with SEC techniques and measurements of molecular weight, molecular size, and concentration. Also discovered is a vinyl polymer resin comprised of from 0.1 to 50 weight percent of non-linear polymers having at least 0.06 branches/1000 backbone carbons, where branching is measured using a heat polymerized polystyrene having from 0.0 to 0.06 branches/1000 backbone carbons as a linear reference.
Abstract:
Disclosed is a bimodal Ziegler-Natta catalyzed polyethylene, having a density of from.930 g/cc to 0.960 g/cc, and a molecular weight distribution of from 10 to 25, wherein an article formed therefrom has a PENT of at least 1500. Also disclosed is a method of preparing a tubular article including obtaining a bimodal polyethylene having a density of from.930 g/cc to 0.960 g/cc and a molecular weight distribution of from 10 to 25, and processing the polyethylene under conditions where a specific energy input (SEI) is less than 300kW.h/ton, and wherein the article has a PENT of at least 1500. Further disclosed is a method for controlling the degradation of polyethylene including polymerizing ethylene monomer, recovering polyethylene, extruding the polyethylene, and controlling the degradation of polyethylene by measuring the SEI to the extruder and adjusting throughput and/or gear suction pressure keep SEI less than 300kW.h/ton, and forming an article.