Ethylene-based polymers having a density of 0.952 to 0.968 g/cm3. a ratio of HLMI/MI from 185 to 550. an IB parameter from 1.46 to 1.80, a tan δ at 0.1 sec.sup.-1 from 1.05 to 1.75 degrees, and a slope of a plot of viscosity versus shear rate at 100 sec.sup.-1 from 0.18 to 0.28 are described, with low melt flow versions having a HLMI from 10 to 30 g/10 min and a Mw from 250,000 to 450,000 g/mol, and high melt flow versions having a HLMI from 30 to 55 g/10 min and a Mw from 200,000 to 300,000 g/mol. These polymers have the processability of chromium-based resins, but with improved stress crack resistance and topload strength for bottles and other blow molded products.

A nucleating agent-free and LLDPE-free polyolefin composition for making films with enhanced barrier properties against water vapor and oxygen gas. Related aspects include formulations, manufactured articles, films, and methods.

A nucleating agent-free and LLDPE-free polyolefin composition for making films with enhanced barrier properties against water vapor and oxygen gas. Related aspects include formulations, manufactured articles, films, and methods.

Apparatuses and processes that produce multimodal polyolefins, and in particular, polyethylene resins, are disclosed herein. This is accomplished by using two reactors in series, where one of the reactors is a multi-zone circulating reactor that can circulate polyolefin particles through two polymerization zones optionally having two different flow regimes so that the final multimodal polyolefin has improved product properties and improved product homogeneity.

Apparatuses and processes that produce multimodal polyolefins, and in particular, polyethylene resins, are disclosed herein. This is accomplished by using two reactors in series, where one of the reactors is a multi-zone circulating reactor that can circulate polyolefin particles through two polymerization zones optionally having two different flow regimes so that the final multimodal polyolefin has improved product properties and improved product homogeneity.

Pellet-stable olefinic copolymer bimodal rubber is made using parallel reactors, with one reactor synthesizing higher molecular weight (MW) rubber with dual catalysts, with an improved molecular weight split ratio and an improved composition distribution of the moderate and ultra-high MW components, while another reactor synthesizes random isotactic polypropylene copolymer (RCP). The effluents are reactor-blended and result in pellet-stable bimodal rubber (P-SBR), which may be pelletized. When making thermoplastic vulcanizates (TPVs) with P-SBR, the need to granulate rubber bales and subsequently use talc, clay, or other anti-agglomeration agents to prevent granulated rubber crumbs from agglomerating are eliminated. TPVs made with P-SBR have vulcanized rubber particles that are smaller and more uniform in size, resulting in TPVs with higher particle counts and more thermoplastic “ligaments” between the particles, with such ligaments being made stronger by the added RCP. Such thus-produced TPVs have a lower hysteresis and flexural modulus, and better elastic properties.

Pellet-stable olefinic copolymer bimodal rubber is made using parallel reactors, with one reactor synthesizing higher molecular weight (MW) rubber with dual catalysts, with an improved molecular weight split ratio and an improved composition distribution of the moderate and ultra-high MW components, while another reactor synthesizes random isotactic polypropylene copolymer (RCP). The effluents are reactor-blended and result in pellet-stable bimodal rubber (P-SBR), which may be pelletized. When making thermoplastic vulcanizates (TPVs) with P-SBR, the need to granulate rubber bales and subsequently use talc, clay, or other anti-agglomeration agents to prevent granulated rubber crumbs from agglomerating are eliminated. TPVs made with P-SBR have vulcanized rubber particles that are smaller and more uniform in size, resulting in TPVs with higher particle counts and more thermoplastic “ligaments” between the particles, with such ligaments being made stronger by the added RCP. Such thus-produced TPVs have a lower hysteresis and flexural modulus, and better elastic properties.

The present invention relates to a multimodal ethylene copolymer composition having a density of 920 to 949 kg/m.sup.3 and a flexural modulus, wherein said flexural modulus is following the equation: Flexural modulus [MPa]<21.35.Math.density [kg/m3]−19585 [1]. The multimodal ethylene copolymer composition according to the invention can be used in a highly flexible cable jacket, preferably a power cable jacket.

A pipe (10) includes a polyethylene-based resin layer (21) containing a polyethylene-based resin composition as a major component. The polyethylene-based resin layer (21) forms a pipeline member inner surface (10a). The polyethylene-based resin composition has a calcium concentration of 10 ppm or more and 60 ppm or less.

A pipe (10) includes a polyethylene-based resin layer (21) containing a polyethylene-based resin composition as a major component. The polyethylene-based resin layer (21) forms a pipeline member inner surface (10a). The polyethylene-based resin composition has a calcium concentration of 10 ppm or more and 60 ppm or less.