Abstract: The invention describes the preparation of long chain branching in high density polyethylene by using metallocene catalysts in the presence of ethylene.

Abstract: A process for the gas-phase copolymerization of: (a) propylene, (b) at least one C4-C8 ?-olefin, and (c) optionally ethylene, the process being carried out in a reactor having two interconnected polymerization zones, wherein the growing polymer particles flow through the first of said polymerization zones (riser) under fast fluidization conditions, leave said riser and enter the second of said polymerization zones (downcomer) through which they flow downward in a densified form, leave said downcomer and are reintroduced into said riser, thus establishing a circulation of polymer between the riser and the downcomer, the gas mixture present in the riser being at least partially prevented from entering the downcomer by introducing into the upper part of said downcomer a liquid barrier having a composition different from the gaseous mixture present in the riser and comprising at least one C4-C8 ?-olefin in a total amount of from 0.1% to 35% by mol.

Abstract: Disclosed herein are processes for preparing procatalyst compositions and polymers, i.e., propylene-based polymers, produced therefrom. The present procatalyst compositions improve catalyst selectivity and also increase the bulk density of the formant polymer.

Abstract: Processes for the production of high strength polyethylene tape articles from high strength ultra-high molecular weight multi-filament yarns, and to the tape articles, fabrics, laminates and impact resistant materials made therefrom.

Abstract: The present invention pertains to a polyethylene film and a process for manufacturing such film. The polyethylene film may have a ratio between the strength in a first direction in the film plane and the strength in a second direction in the film plane perpendicular to the first direction in the range of 0.1-10:1, the strength in at least one direction being at least 0.2 Gpa. The process for manufacturing a polyethylene film may have a starting UHMWPE polymer with an average molecular weight of at least 500,000 grams/mole, an elastic shear modulus determined directly after melting at 160° C. of at most 1.4 MPa, and a Mw/Mn ratio of at most 6 to a solvent-free compacting process and a stretching process under such conditions that at no point during the process the temperature of the intermediate polymer film is raised to a value above its melting point.

Abstract: A manufacturing system for producing polyolefin includes a polymerization reactor, a flash chamber, and a purge column. In certain embodiments, the purge column may receive a solids stream directly from the flash chamber. Further, the purge column may function as a feed tank for an extruder within an extrusion/loadout system. According to certain embodiments, the manufacturing system may be configured to consume less than 445 kilowatt-hours of energy per metric ton of polyolefin produced based on consumption of electricity, steam, and fuel gas.

Abstract: Provided are ethylene-based polymer compositions, articles made therefrom, and methods of making the same. Ethylene-based polymer compositions include blends of a linear low density polyethylene prepared with metallocene catalyst and a low density polyethylene. The linear low density polyethylene may optionally have about five mole percent or less of monomer units derived from an alpha-olefin comonomer. Articles composed of such ethylene-based polymer compositions, such as blown films, exhibit favorable physical properties, including excellent optical properties and retained strength i.e., mitigation of expected decline in physical strength due to LDPE addition.

Abstract: Elevated temperature electrospinning apparatus comprises a pump upstream of or containing a resistance heater, means to shield applied electrostatic field from the resistance heater, and a temperature modulator for modulating temperature in the spinning region.

Abstract: New ethylene polymers having broad molecular weight distribution and long-chain branching, above all at high molecular weight fractions; the polymers have strain hardening equal or higher than 1.4 (at constant elongational rate of 0.5 s?1, at 150° C.), branching index g? equal or lower than 0.9 (at Mw of 2·106 g/mol). The polymers are prepared by using a mixed catalyst system comprising a polymerization catalyst based on a late transition metal component having a tridentate ligand, and a Ziegler polymerization catalyst annealed at a temperature higher than 100° C., for a time of at least 10 minutes.

Abstract: The invention relates to a process for the production of high density polyethylene by polymerisation of ethylene in the presence of a silylchromate based catalyst and a reducing agent is characterized in that the reducing agent comprises the reaction mixture of an alkyl aluminium compound and/or boron compound and a nitrogen containing compound. The alkyl aluminium compound is an organo aluminium compound having the formula AlR3, in which R is a hydrocarbon radical containing 1-10 carbon atom and the nitrogen containing compound comprises —NH2, —NHR, —NR2, wherein R may be alkyl or a substituted alkyl having from 1 to 40 carbon atoms.

Abstract: One embodiment of the present invention provides polymer crystalline materials containing crystals of the polymer and satisfying the following requirements (I) and (II) or the following requirements (I) and (III): (I) the polymer crystalline materials a crystallinity of 70% or greater; (II) the crystals are 300 nm or less in size; and (III) the crystals have a number density of 40 ?m?3 or greater. This allows an embodiment of the present invention to provide polymer crystalline materials which are excellent in properties such as mechanical strength, heat tolerance, and transparency or, in particular, polymer crystalline materials, based on a general-purpose plastic such as PP, which is excellent in properties such as mechanical strength, heat tolerance, and transparency.

Abstract: The invention is directed to a metallocene catalyst system and a process for preparing the system. The metallocene catalyst system comprises a support and metallocene bound substantially throughout the support. The selection of certain supports facilitates the production of metallocene catalyst systems having increased catalytic activity than previously recognized.

Abstract: The present invention provides an ethylene-based polymer composition characterized by a Comonomer Distribution Constant in the range of from greater than 45 to less than 400, wherein the composition has less than 120 total unsaturation unit/1,000,000C, and method of producing the same.

Abstract: A solid catalyst component comprising the product of a process comprising (a) reacting a magnesium alcoholate of formula Mg(OR1)(OR2) compound, in which R1 and R2 are identical or different and are each an alkyl radical having 1 to 10 carbon atoms, with titanium tetrachloride carried out in a hydrocarbon at a temperature of 50-100° C., (b) subjecting the reaction mixture obtained in (a) to a heat treatment at a temperature of 110° C. to 200° C. for a time ranging from 3 to 25 hours (c) isolating and washing with a hydrocarbon the solid obtained in (b), said solid catalyst component having a Cl/Ti molar ratio higher than 2.5.

Abstract: The present disclosure includes a waterborne polyolefin based coating layer that has improved features as compared to epoxy coatings. The coating composition of the present disclosure include 40 to 80 weight percent (wt. %) of a base polymer; 10 to 30 wt. % of a polymeric stabilizing agent; 5 to 15 wt. % of a polymeric coupling agent; 0 to 35 wt. % of a polymeric performance improving agent; a neutralizing agent that partially or fully neutralize the polymeric stabilizing agent; and a fluid medium, where the wt. % values are based on the total weight of the base polymer, the polymeric coupling agent, the polymeric stabilizing agent and, when present, the polymeric performance improving agent (as used herein, this total weight of the base polymer, the polymeric coupling agent, the polymeric stabilizing agent and, when present, the polymeric performance improving agent may be referred to as the “solid content” of the coating composition).

Abstract: A multimodal polyethylene composition comprising at least three ethylene polymer fractions having distinct molecular weights or comonomer contents, the at least three ethylene polymer fractions comprising at least one first ethylene polymer fraction having a first molecular weight, at least one second ethylene polymer fraction having a second molecular weight higher than the first molecular weight, and at least one third ethylene polymer fraction having a third molecular weight higher than the first molecular weight, wherein the at least one first ethylene polymer fraction and the at least third ethylene polymer fraction are prepared by the use of a first and, respectively, third catalyst of the single site type.

Abstract: A process is taught, comprising polymerizing ethylene in the presence of a catalyst to form a crystalline ethylene-based polymer having a crystallinity of at least 50% as determined by DSC Crystallinity in a first reactor or a first part of a multi-part reactor and reacting the crystalline ethylene-based polymer with additional ethylene in the presence of a free-radical initiator to form an ethylenic polymer in at least one other reactor or a later part of a multi-part reactor.

Abstract: The application relates to a polyethylene composition having a base resin, the base resin comprising (A) a first polyethylene fraction, and (B) a second polyethylene fraction, wherein the melt flow rate MFR5/190° c. of the first fraction is higher than the melt flow rate MFR5/190° c. of the second fraction, the flow rate ratio FRR21/5 of the polyethylene composition, defined as the ratio of melt flow rate MFR21-6/190° c. to melt flow rate MFR5/190° c., is within the range of 15-28, and 10 the melt flow rate MFR5/190° c. of the polyethylene composition is within the range of 0.5-1.1 g/10 min.

Abstract: A resin composition includes a polyolefin resin. A viscosity of the resin composition is within a range of not less than 500 Pa·s and not more than 2300 Pa·s under measurement conditions of a measurement temperature of 170° C. and a measurement frequency of 1 Hz. A strain hardening rate of the resin composition in uniaxial elongational viscosity measured under measurement conditions of a measurement temperature of 150° C. and a strain rate of 3.0 s?1 is not less than 800%. A foam insulated wire includes a conductor, and a foam insulation of the resin composition extruded on an outer periphery of thereof. A diameter of the conductor is 3.5 to 18 mm, and an outer diameter of the foam insulation is not less than 8 mm.

Abstract: An ethylene polymer having (i) a density defined by equation (1) ?>a?b Log M??(1) where ? is a density of the polymer in g/cc, log M is a log weight average molecular weight of the polymer, a is about 1.0407, and b is about 0.0145; and (ii) a polydispersity index of greater than about 5.

Abstract: Pyridyldiamido transition metal complexes are disclosed for use in alkene polymerization.

Abstract: Process for the preparation of ethylene homopolymers or copolymers in the presence of free-radical polymerization initiator at from 100° C. to 350° C. and pressures in the range of from 160 MPa to 350 MPa in a high-pressure polymerization unit comprising a high-pressure reactor with one or more reaction zones, to each of which free-radical polymerization initiator is fed, which is controlled by a model based predictive controller carrying out the steps.

Abstract: The invention relates to a creep-optimized ultrahigh molecular weight polyethylene (UHMWPE) fiber obtained by spinning an UHMWPE comprising olefinic branches (OB) and having an elongational stress (ES), and a ratio (OB/1000 C/ES) between the number of olefinic branches per thousand carbon atoms (OB/1000 C) and the elongational stress (ES) of at least 0.2, wherein said UHMWPE fiber when subjected to a load of 600 MPa at a temperature of 70° C., has a creep lifetime of at least 90 hours.

Abstract: A method comprising (a) contacting a support and a chromium-containing compound to form chromium-containing support, (b) heat treating the chromium-containing support in an oxidizing atmosphere to form a treated support, (c) contacting the treated support with carbon monoxide to form a CO-contacted support, and (d) contacting the CO-contacted support with hydrogen to form a catalyst. A method comprising oxidizing a chromium-treated support to form a polymerization catalyst, contacting the polymerization catalyst with carbon monoxide to form a reduced polymerization catalyst, contacting the reduced polymerization catalyst with hydrogen to form an activated polymerization catalyst, and contacting the activated polymerization catalyst with ethylene in a reaction zone under suitable reaction conditions to form a random copolymer.

Abstract: A plastic pallet having a fire retardant. The fire retardant is prepared in an FR masterbatch before mixing with HDPE to form the pallet. In one embodiment, the FR masterbatch includes a brominated fire retardant, a hydrated mineral, antimony trioxide and a carrier resin. In some embodiments, the brominated fire retardant is a non-blooming brominated fire retardant such as poly pentabromobenzyl acrylate or ethylenebistetrabromophthalamide. The hydrated mineral advantageously enhances both the vapor phase and condensed phase fire retardant properties of the final product and may be magnesium hydroxide. In other embodiments, melamine pyrophosphate or a blend of melamine pyrophosphate and polyhydric compound may be substituted for the hydrated mineral or used as the sole fire retardant. The polyhydric compound may be bis-pentaerythritol phosphate alcohol. A method of manufacturing a plastic pallet is also disclosed.

Abstract: Thiobis phenolic antioxidants are efficiently dry or melt blended with a tree-resistant, crosslinkable polyethylene by first forming a blend, preferably a dry blend, of the antioxidant with a polyalkylene glycol (PAG), and then mixing the blend with the polyethylene. The incorporation of thiobis phenolic antioxidant and PAG blend into polyethylene provides the PE with high oxidative induction time (OIT) which is a measure of the oxidative stability of the PE.

Abstract: A method of treating a polymerization reactor effluent stream comprising recovering the reactor effluent stream from the polymerization reactor, flashing the reactor effluent stream to form a flash gas stream, separating the flash gas stream into a first top stream, a first bottom stream, and a side stream, wherein the side stream substantially comprises hexane, separating the first top stream into a second top stream and a second bottom stream, wherein the second bottom stream substantially comprises isobutane, and separating the second top stream into a third top stream and a third bottom stream; wherein the third top stream substantially comprises ethylene, and wherein the third bottom stream is substantially free of olefins.

Abstract: This invention relates to processes to produce polyethylene involving contacting ethylene with a metallocene catalyst system; wherein the catalyst system comprises: a stoichiometric activator; and a metallocene compound. The metallocene catalyst system is also disclosed.

Abstract: An apparatus for forming particles from a liquid, including a rotor assembly having at least one surface sized and shaped so as to define at least one capillary. Each capillary has an inner region adjacent an axis of rotation of the rotor assembly, an outer region distal from the axis of rotation, and an edge adjacent the outer region. The rotor assembly is configured to be rotated at an angular velocity selected such that when the liquid is received in the inner region of the at least one capillary, the liquid will move from the inner region to the outer region, adopt an unsaturated condition on the at least one surface such that the liquid flows as a film along the at least one surface and does not continuously span the capillary, and, upon reaching the edge, separates from the at least one surface to form at least one particle.

Abstract: A method of treating a polymerization reactor effluent stream comprising recovering the reactor effluent stream from the polymerization reactor, flashing the reactor effluent stream to form a flash gas stream, separating the flash gas stream into a first top stream, a first bottom stream, and a side stream, wherein the side stream substantially comprises hexane, separating the first top stream into a second top stream and a second bottom stream, wherein the second bottom stream substantially comprises isobutane, and separating the second top stream into a third top stream and a third bottom stream; wherein the third top stream substantially comprises ethylene, and wherein the third bottom stream is substantially free of olefins.

Abstract: A method of producing an improved polyethylene, especially an ultra-high molecular weight polyethylene utilizes a sequential irradiation and annealing process to form a highly cross-linked polyethylene material. The use of sequential irradiation followed by sequential annealing after each irradiation allows each dose of irradiation in the series of doses to be relatively low while achieving a total dose which is sufficiently high to cross-link the material. The process may either be applied to a preformed material such as a rod or bar or sheet made from polyethylene resin or may be applied to a finished polyethylene part.

Abstract: The present invention generally provides implantable articles and methods of forming implantable articles from a crosslinked ultrahigh molecular weight polyethylene (“UHMWPE”) blend stabilized with Vitamin E. The crosslinked UHMWPE blend may be prepared by combining the UHMWPE material and vitamin E prior to irradiating the UHMWPE blend with electron beam radiation at a sufficient radiation dose rate to induce crosslinking. The crosslinked UHMWPE blend may be incorporated into a variety of implants, and in particular, into endoprosthetic joint replacements.

Abstract: Disclosed herein is a method for separating from the reactor effluent of an olefin oligomerization procedure those catalyst materials and polymeric by-products which can cause difficulties in the downstream processing of such effluent. Polymer by-products and catalyst in the effluent are separated from reaction products by flash vaporization utilizing an in-situ hot solvent which is contacted with the effluent and serves as the heating medium to promote this flash vaporization step. Subsequent processing of a liquid portion of the effluent which is left after flash vaporization involves recovery of catalyst and polymeric by-products therefrom in a steam stripping vessel. Also disclosed is a multiple reactor system which can be used for continuous trimerization of ethylene to 1-hexene while at the same time washing polymeric by-products from one of the reactors in the series using a wash oil solvent.

Abstract: A molded polyethylene component that comprises polyethylene having a melt flow index of about 3.5 g/10 min or greater as measured by ASTM D1238 at 190° C./21.5 kg weight and having an ash content of about 500 ppm or less may be useful biomedical devices, including kits and methods relating thereto.

Abstract: This invention relates to a co-oligomer having an Mn of 300 to 30,000 g/mol comprising 10 to 90 mol % propylene and 10 to 90 mol % of ethylene, wherein the oligomer has at least X % allyl chain ends, where: 1) X=(?0.94(mole % ethylene incorporated)+100), when 10 to 60 mole % ethylene is present in the co-oligomer, and 2) X=45, when greater than 60 and less than 70 mole % ethylene is present in the co-oligomer, and 3) X=(1.83*(mole % ethylene incorporated)?83), when 70 to 90 mole % ethylene is present in the co-oligomer. This invention also relates to a homo-oligomer, comprising propylene, wherein the oligomer has: at least 93% allyl chain ends, an Mn of about 500 to about 20,000 g/mol, an isobutyl chain end to allylic vinyl group ratio of 0.8:1 to 1.2:1.0, and less than 100 ppm aluminum. This invention also relates to a process of making homo-oligomer, comprising propylene, wherein the productivity is greater than 4500 g/mmol Hf (or Zr)/hour.

Abstract: The invention relates to an improved process for manufacturing an olefin polymer composition, in particular polyethylene, that incorporates two or more reaction zones in an optimized configuration that ease product transitions and allows for improved reactor quality control.

Abstract: A novel polymer composition is described comprising ethylene homopolymers and/or copolymers of ethylene with C3-C8-alpha-olefins which polymer composition has a density of from 0.940 to 0.949 g/cm3, a melt index (HLMI) according to DIN EN ISO 1133:2005, condition G at 190° C. and 21.6 kg, of from 3 to 7 g/10 min. and a Hostalen Long Chain Branching Index (HLCBI) of from 3 to 8, and which polymer composition is produced by polymerisation with one or more Ziegler catalysts in a series of at least two polymerization reactors. The new polymer composition can in particular be used for blow moulding of intermediate bulk containers.

Abstract: The invention relates to a process for preparing polyolefin in a loop reactor. The polymer is prepared by polymerizing olefin monomers in the presence of a catalyst to produce a polyolefin slurry while pumping said slurry through said loop reactor by means of a pump. The present process is characterized in that the catalyst is fed in the loop reactor at a distance to the pump. The invention allows production of the polymer with advantageous properties while leading to fewer blockages of the reactor.

Abstract: Solid-state shear pulverization of semi-crystalline polymers and copolymers thereof and related methods for enhanced crystallization kinetics and physical/mechanical properties.

Abstract: The field of the invention relates generally to a method for preparing very-high or ultra-high molecular weight polyethylene. More particularly, the present invention related to a method of preparing very-high or ultra-high molecular weight polyethylene using a supported catalyst comprising a support, an activator and a metal-ligand complex, as well as the catalyst itself. The present invention additionally relates to a method of using a supported catalyst comprising a support, an activator and co-supported metal-ligand complexes to obtain a bi-modal molecular weight distribution of polyethylene.

Abstract: The present invention provides a highly functional polyethylene fiber exhibiting reduction of change in their physical properties in a wide range of temperatures for processing for products and in a wide range of temperatures for usage as products, thereby enabling improvement of dimensional stability. In addition, the present invention provides a highly functional polyethylene fiber exhibiting a high degree of dye exhaustion to be obtained in a simple dyeing operation, and excellent color fastness. The highly functional polyethylene fiber of the present invention is characterized in that an intrinsic viscosity [?] is higher than or equal to 0.8 dL/g, and not higher than 4.9 dL/g, ethylene is substantially contained as a repeating unit thereof, and a maximum thermal shrinkage stress is less than or equal to 0.4 cN/dtex in TMA (thermo-mechanical analysis), and a thermal shrinking percentage at 100° C. is less than or equal to 2.5%.

Abstract: A polyethylene powder is described having a molecular weight in the range of from 3,000,000 g/mol to less than 4,000,000 g/mol as determined by ASTM 4020 and a bulk density of 0.10 to 0.20 g/cm3. On sintering, the polyethylene powder produces a porous article having an elastic modulus of at least 90 MPa.

Abstract: Disclosed is a high-density polyethylene (HDPE) composition that comprises at least a first high density polyethylene component having a density of 0.940-0.968 g/cm3 and a melt index I2.16 of 0.5-10.0 dg/min and a melt flow ratio (flow index I21.6 at 190° C. divided by melt index I2.16 at 190° C.) of at least 25. A second HDPE component may be included in the composition with melt index I2.16 of greater than 10 dg/min and melt flow ratio of 30 or less. The disclosed compositions are suitable for use in living hinge closure applications.

Abstract: The disclosed process is for the production of polyethylene by gas phase polymerisation of ethylene in the presence of a supported chromium oxide based catalyst which is modified with an amino alcohol wherein the molar ratio of amino alcohol:chromium ranges between 0.5:1 and 1:1, wherein the support is silica having a surface area (SA) between 250 m2/g and 400 m2/g and a pore volume (PV) between 1.1 cm3/g and less than 2.0 cm3/g and wherein the amount of chromium in the supported catalyst is at least 0.1% by weight and less than 0.5% by weight.

Abstract: The present invention relates to a method for optimizing the sequential feeding of at least two ethylene polymerization catalysts to an ethylene polymerization reactor, comprising: transferring to a mixing vessel a first ethylene polymerization catalyst and a first diluent, decreasing the concentration of said first ethylene polymerization catalyst in said mixing vessel, transferring to said mixing vessel a second ethylene polymerization catalyst and a second diluent, progressively replacing said first ethylene polymerization catalyst by said second ethylene polymerization catalyst and said first diluent by said second diluent, increasing the concentration of said second ethylene polymerization catalyst in said mixing vessel, sequentially transferring said first ethylene polymerization catalyst and said second ethylene polymerization catalyst from said mixing vessel to an ethylene polymerization reactor.

Abstract: The invention relates to A process for the polymerization of ethylene to produce a polyethylene resin in at least two slurry loop reactors connected to each other in series, the resin having a bimodal molecular weight distribution, a molecular weight distribution MWD of at least 7.0, an HLMI of from 1 to 100 g/10 min, and a density of from 0.935 to 0.960 g/cm3, wherein in one reactor 30 to 47 wt % based on the total weight of the polyethylene resin of a high molecular weight (HMW) polyethylene fraction is produced having an HL275 of from 0.05 to 1.8 g/10 min (the equivalent of HLMI of from 0.01 to 1.56 g/10 min), a density of from 0.925 to 0.942 g/cm3 and an MWD of at least 5.0, and in the other reactor a low molecular weight (LMW) polyethylene fraction is produced having an HLMI of from 10 to 1500 g/10 min and a density of from 0.960 to 0.975 g/cm3, in the presence of a Ziegler-Natta catalyst system.

Abstract: Disclosed is a high-density polyethylene (HDPE) composition that comprises at least a first high density polyethylene component having a density of 0.940-0.968 g/cm3 and a melt index I2.16 of 0.5-10.0 dg/min and a melt flow ratio (flow index I21.6 at 190° C. divided by melt index I2.16 at 190° C.) of at least 25. A second HDPE component may be included in the composition with melt index I2.16 of greater than 10 dg/min and melt flow ratio of 30 or less. The disclosed compositions are suitable for use in living hinge closure applications.

Abstract: The present invention relates to an apparatus and process for the gas phase polymerisation of olefins, the apparatus comprising: a) a reaction zone comprising a grid at its base, b) an inlet located in the lower half of the reaction zone for introduction of a reaction gas to the reaction zone, c) an outlet located in the upper half of the reaction zone for removal of the reaction gas from the reaction zone, and d) a solids separation unit having an inlet fluidly connected to the outlet for removal of the reaction gas from the reaction zone, characterised in that the inlet of the solids separation unit is located at a vertical height lower than the outlet for removal of reaction gas from the reaction zone and such that the angle to the horizontal of a straight line drawn between the inlet of the solids separation unit and the outlet for removal of reaction gas from the reaction zone is greater than 20°.

Abstract: Group 4 metal complexes comprising a polyvalent, heteroaryl donor ligand and their use as components of olefin polymerization catalysts, especially suited for preparing propylene/ethylene copolymer products having high isotacticity and low molecular weight, are disclosed.

Abstract: The present invention provides dual catalyst systems containing a metallocene catalyst and a hydrogen scavenging catalyst, and polymerization processes employing these dual catalyst systems. Due to a reduction in hydrogen levels in the polymerization processes, olefin polymers produced from these polymerization processes may have a higher molecular weight, a lower melt index, and higher levels of unsaturation.