New polypropylene composition which combines low sealing initiation temperature (SIT), high hot-tack and good mechanical properties, like high dart drop strength (DDI), and its use especially for film applications.

A method can be used for manufacturing an ethylene-propylene-diene terpolymer for a fuel cell. A polymerization step includes subjecting an organic chelate compound forming a coordinate bond, a vanadium-based Ziegler-Natta catalyst, an organoaluminum compound, and ethylene, propylene, and diene monomers, together with a solvent, to polymerization in a reactor. A separation step includes recovering residual catalysts and unreacted monomers from the stream discharged from the reactor. An acquisition step includes recovering the solvent from the stream deprived of the residual catalysts and unreacted monomers to acquire the ethylene-propylene-diene terpolymer.

Provided are methods for producing bimodal polyolefins comprising the steps of contacting α-olefin monomers with a catalyst in slurry polymerization conditions in the presence of zero to minimum hydrogen to produce a high molecular weight polyolefin and contacting additional α-olefin monomers in gas phase polymerization conditions and the high molecular weight polyolefin and the catalyst to produce bimodal polyolefin having high stiffness and broad molecular weight distribution. An additional step of polymerizing the bimodal polyolefin with a comonomer in a second gas phase can provide a bimodal impact copolymer having high stiffness and broad molecular weight distribution. Among the advantages of the present methods, bimodal polyolefins can be produced in a continuous process between a slurry polymerization reactor and a gas phase polymerization reactor without a venting step in between and with minimal hydrogen in the slurry polymerization reactor.

Disclosed herein are ethylene-based polymers generally characterized by a density of at least 0.94 g/cm.sup.3, a high load melt index from 4 to 20 g/10 min, a zero-shear viscosity at 190° C. from 20,000 to 400,000 kPa-sec, and a relaxation time at 190° C. from 225 to 3000 sec. These ethylene polymers can be produced by peroxide-treating a broad molecular weight distribution Ziegler-catalyzed resin, and can be used in large diameter, thick wall pipes and other end-use applications.

Polymer compositions may include a matrix phase comprising a polypropylene-based polymer; and an elastomeric rubber phase; wherein the polymer composition has melt flow rate (MFR) according to ASTM D1238 at 230° C./2.16 kg equal to or greater than 90 g/10 min and at least one feature selected from (I) an Izod impact resistance according to ASTM D256A at 23° C. equal to or greater than 400 J/m; (II) an instrumented drop impact at −30° C., average total energy, equal to or greater than 17 J; or (III) an instrumented drop impact at −30° C., average percent ductility, equal to or greater than 60%.

A polyethylene composition for producing blow-molded hollow articles, having the following features: 1) density from 0.940 to 0.955 g/cm.sup.3, determined according to ISO 1183 at 23° C.; 2) ratio MIF/MIP from 12 to 40; 3) Mz from 500,000 to 3,500,000 g/mol; 4) η.sub.0.02 from 80,000 to 300,000 Pa.Math.s; 5) HMWcopo index from 1 to 15; and 6) Mz/Mw*LCBI lower than 6.4.

The invention relates to a process for production of copolymers, in particular for the polymerization of propylene, and another monomer chosen from a group comprising ethylene and a C4-C12 α-olefin in a horizontal stirred reactor comprising an agitated bed and several reaction zones for forming polymer particles.

The present invention relates to a heterophasic polypropylene composition with an improved property profile, e.g. improved balance of toughness, softness and haze, comprising a heterophasic propylene copolymer and a copolymer of propylene and 1-hexene.

Embodiments of polymer compositions and articles comprising such compositions contain at least one multimodal ethylene-based polymer having at least three ethylene-based components, wherein the multimodal ethylene-based polymer exhibits improved toughness.

Provided herein are methods of polymerizing α-olefin monomer with a catalyst and hydrogen in a slurry to produce low molecular weight polyolefins. Hydrogen is vented from the low molecular weight polyolefins and then the low molecular weight polyolefins are further polymerized in a gas phase to produce a polyolefin having a molecular weight distribution of between 4.0 and 30 and a flexural modulus between 1500 mPa and 2500 mPa.