Embodiments of the present disclosure are directed towards method for modifying a polymer flow index. As an example, a method for modifying a polymer flow index can include providing monomers to a polymerization reactor, providing a chromium catalyst to the polymerization reactor, and providing an active amount of a flow index modifier to the polymerization reactor, wherein the flow index modifier is selected from carbon dioxide, carbon monoxide, 2,4-hexadiene, and combinations thereof.

Embodiments of the present disclosure are directed towards method for modifying a polymer flow index. As an example, a method for modifying a polymer flow index can include providing monomers to a polymerization reactor, providing a chromium catalyst to the polymerization reactor, and providing an active amount of a flow index modifier to the polymerization reactor, wherein the flow index modifier is selected from carbon dioxide, carbon monoxide, 2,4-hexadiene, and combinations thereof.

Embodiments of the present disclosure are directed towards method for modifying a polymer flow index. As an example, a method for modifying a polymer flow index can include providing monomers to a polymerization reactor, providing a chromium catalyst to the polymerization reactor, and providing an active amount of a flow index modifier to the polymerization reactor, wherein the flow index modifier is selected from carbon dioxide, carbon monoxide, 2,4-hexadiene, and combinations thereof.

Methods for preparing supported chromium catalysts containing a chromium (III) compound and an activator-support are disclosed. These supported chromium catalysts can be used in catalyst compositions for the polymerization of olefins to produce polymers having low levels of long chain branching, and with greater sensitivity to the presence of hydrogen during polymerization.

Supported chromium catalysts with an average valence less than +6 and having a hydrocarbon-containing or halogenated hydrocarbon-containing ligand attached to at least one bonding site on the chromium are disclosed, as well as ethylene-based polymers with terminal alkane, aromatic, or halogenated hydrocarbon chain ends. Another ethylene polymer characterized by at least 2 wt. % of the polymer having a molecular weight greater than 1,000,000 g/mol and at least 1.5 wt. % of the polymer having a molecular weight less than 1000 g/mol is provided, as well as an ethylene homopolymer with at least 3.5 methyl short chain branches and less than 0.6 butyl short chain branches per 1000 total carbon atoms.

Supported chromium catalysts with an average valence less than +6 and having a hydrocarbon-containing or halogenated hydrocarbon-containing ligand attached to at least one bonding site on the chromium are disclosed, as well as ethylene-based polymers with terminal alkane, aromatic, or halogenated hydrocarbon chain ends. Another ethylene polymer characterized by at least 2 wt. % of the polymer having a molecular weight greater than 1,000,000 g/mol and at least 1.5 wt. % of the polymer having a molecular weight less than 1000 g/mol is provided, as well as an ethylene homopolymer with at least 3.5 methyl short chain branches and less than 0.6 butyl short chain branches per 1000 total carbon atoms.

The present invention relates to a ligand compound, a catalyst system for olefin oligomerization and a method for oligomerizing an olefin using same. The catalyst system for olefin oligomerization according to the present invention exhibits high selectivity to 1-hexene or 1-octene while having excellent catalytic activity, thus enabling more efficient preparation of alpha-olefins.

The present invention relates to a ligand compound, a catalyst system for olefin oligomerization and a method for oligomerizing an olefin using same. The catalyst system for olefin oligomerization according to the present invention exhibits high selectivity to 1-hexene or 1-octene while having excellent catalytic activity, thus enabling more efficient preparation of alpha-olefins.

A polyethylene composition comprising a granular polyethylene resin characterized by a resin solid density of from 0.91 to 0.97 g/cm.sup.3, a ratio of intraparticle void volume to interparticle void volume of from 0.33 to 0.67, and a total resin porosity, total, of equal to or greater than 0.45 is provided. Further provided are articles made from the polyethylene composition.

A polyethylene composition comprising a granular polyethylene resin characterized by a resin solid density of from 0.91 to 0.97 g/cm.sup.3, a ratio of intraparticle void volume to interparticle void volume of from 0.33 to 0.67, and a total resin porosity, total, of equal to or greater than 0.45 is provided. Further provided are articles made from the polyethylene composition.