The present invention concerns a process for the preparation of a copolymer comprising the steps of copolymerizing under suitable reaction conditions at least one first type of olefin monomer and at least one second type of functionalized olefin monomer using a catalyst system to obtain a polyolefin main chain having one or multiple functionalized short chain branches, the catalyst system comprising: i) a single-site catalyst or catalyst precursor comprising a metal selected from Ti3+ or Cr3+; ii) a co-catalyst; iii) optionally a scavenger.

The present invention concerns a process for the preparation of a copolymer comprising the steps of copolymerizing under suitable reaction conditions at least one first type of olefin monomer and at least one second type of functionalized olefin monomer using a catalyst system to obtain a polyolefin main chain having one or multiple functionalized short chain branches, the catalyst system comprising: i) a single-site catalyst or catalyst precursor comprising a metal selected from Ti3+ or Cr3+; ii) a co-catalyst; iii) optionally a scavenger.

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.

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 are bimodal linear low density polyethylene copolymers (B-LLDPE copolymers) that have a combination of improved properties comprising at least one processability characteristic similar or better than that of an unblended monomodal ZN-LLDPE and a dart impact property similar or better than that of an unblended monomodal MCN-LLDPE. For the various aspects, the B-LLDPE copolymer has a density from 0.8900 to 0.9300 g/cm.sup.3; a melt index (I.sub.2) from 0.1 g/10 min. to 5 g/10 min.; a M.sub.z from 600,000 to 1,900,000 g/mol; and a SHI from 5.35 to 75 η*(1.0)/η*(100). The B-LLDPE copolymer can be further characterized by a first melt flow ratio (I.sub.21/I.sub.2) from 32 to 140 and a first molecular weight ratio (M.sub.z/M.sub.w) from 4.5 to 11.

Provided are bimodal linear low density polyethylene copolymers (B-LLDPE copolymers) that have a combination of improved properties comprising at least one processability characteristic similar or better than that of an unblended monomodal ZN-LLDPE and a dart impact property similar or better than that of an unblended monomodal MCN-LLDPE. For the various aspects, the B-LLDPE copolymer has a density from 0.8900 to 0.9300 g/cm.sup.3; a melt index (I.sub.2) from 0.1 g/10 min. to 5 g/10 min.; a M.sub.z from 600,000 to 1,900,000 g/mol; and a SHI from 5.35 to 75 η*(1.0)/η*(100). The B-LLDPE copolymer can be further characterized by a first melt flow ratio (I.sub.21/I.sub.2) from 32 to 140 and a first molecular weight ratio (M.sub.z/M.sub.w) from 4.5 to 11.

Provided is an ethylene/1-butene copolymer having excellent processability and stress cracking resistance. The ethylene/1-butene copolymer according to the present invention may be applied to a high-pressure resistant heating pipe, a PE-RT pipe, a large diameter pipe, etc.

Provided is an ethylene/1-butene copolymer having excellent processability and stress cracking resistance. The ethylene/1-butene copolymer according to the present invention may be applied to a high-pressure resistant heating pipe, a PE-RT pipe, a large diameter pipe, etc.

Supported chromium catalysts containing a solid oxide and 0.1 to 15 wt. % chromium, in which the solid oxide or the supported chromium catalyst has a particle size span from 0.5 to 1.4, less than 3 wt. % has a particle size greater than 100 μm, and less than 10 wt. % has a particle size less than 10 μm, can be contacted with an olefin monomer in a loop slurry reactor to produce an olefin polymer. Representative ethylene-based polymers produced using the chromium catalysts have a HLMI of 4 to 70 g/10 min, a density from 0.93 to 0.96 g/cm.sup.3, from 150 to 680 ppm solid oxide (such as silica), from 1.5 to 6.8 ppm chromium, and a film gel count of less than 15 catalyst particle gels per ft.sup.2 of 25 micron thick film and/or a gel count of less than or equal to 50 catalyst particles of greater than 100 μm per five grams of the ethylene polymer.

Supported chromium catalysts containing a solid oxide and 0.1 to 15 wt. % chromium, in which the solid oxide or the supported chromium catalyst has a particle size span from 0.5 to 1.4, less than 3 wt. % has a particle size greater than 100 μm, and less than 10 wt. % has a particle size less than 10 μm, can be contacted with an olefin monomer in a loop slurry reactor to produce an olefin polymer. Representative ethylene-based polymers produced using the chromium catalysts have a HLMI of 4 to 70 g/10 min, a density from 0.93 to 0.96 g/cm.sup.3, from 150 to 680 ppm solid oxide (such as silica), from 1.5 to 6.8 ppm chromium, and a film gel count of less than 15 catalyst particle gels per ft.sup.2 of 25 micron thick film and/or a gel count of less than or equal to 50 catalyst particles of greater than 100 μm per five grams of the ethylene polymer.