Embodiments are directed towards polyolefin compositions including a high molecular weight polyolefin and a low molecular weight polyolefin.

Embodiments are directed towards polyolefin compositions including a high molecular weight polyolefin and a low molecular weight polyolefin.

A polyethylene comprising of ethylene derived units and 0.5 wt % to 10 wt % C.sub.3 to C.sub.12 α-olefin derived units may be synthesized using a mixed catalyst that comprises rac-dimethylsilylbis(tetrahydroindenyl)zirconium dichloride and a zirconium co-catalyst in a mole ratio of 50:50 to 90:10, and wherein the zirconium co-catalyst is a poor comonomer incorporator as compared to the rac-dimethylsilylbis(tetrahydroindenyl)zirconium dichloride catalyst. Such a polyethylene may have a density of 0.91 g/cm.sup.3 to 0.93 g/cm.sup.3, an I.sub.2 value of 0.5 g/10 min to 2 g/10 min, an I.sub.21 value of 25 g/10 min to 75 g/10 min, an I.sub.21/I.sub.2 ratio of 25 to 75, a molar reversed-co-monomer index (RCI,m) of 30 to 180, a phase angle equal or lower than 70° at complex modulus G* of 10,000 Pa, a Θ.sub.2 of 1.5 radians to −1.5 radians, and a low density population of 50% and 70% by weight of the polyethylene.

A polyethylene comprising of ethylene derived units and 0.5 wt % to 10 wt % C.sub.3 to C.sub.12 α-olefin derived units may be synthesized using a mixed catalyst that comprises rac-dimethylsilylbis(tetrahydroindenyl)zirconium dichloride and a zirconium co-catalyst in a mole ratio of 50:50 to 90:10, and wherein the zirconium co-catalyst is a poor comonomer incorporator as compared to the rac-dimethylsilylbis(tetrahydroindenyl)zirconium dichloride catalyst. Such a polyethylene may have a density of 0.91 g/cm.sup.3 to 0.93 g/cm.sup.3, an I.sub.2 value of 0.5 g/10 min to 2 g/10 min, an I.sub.21 value of 25 g/10 min to 75 g/10 min, an I.sub.21/I.sub.2 ratio of 25 to 75, a molar reversed-co-monomer index (RCI,m) of 30 to 180, a phase angle equal or lower than 70° at complex modulus G* of 10,000 Pa, a Θ.sub.2 of 1.5 radians to −1.5 radians, and a low density population of 50% and 70% by weight of the polyethylene.

This invention relates bisindenyl metallocene catalyst compounds having long (at least 4 carbon atoms) linear alkyl groups substituted at the two position and substituted or unsubstituted aryl groups at the four position and process using such catalyst compounds, particularly in the solution process at higher temperatures.

This invention relates bisindenyl metallocene catalyst compounds having long (at least 4 carbon atoms) linear alkyl groups substituted at the two position and substituted or unsubstituted aryl groups at the four position and process using such catalyst compounds, particularly in the solution process at higher temperatures.

Provided are a pellet-type polyethylene resin composition capable of improving pipe pressure resistance property, dimensional stability, and processability at the same time, and a method of preparing the same.

Provided are a pellet-type polyethylene resin composition capable of improving pipe pressure resistance property, dimensional stability, and processability at the same time, and a method of preparing the same.

A diblock polymer composed of a first block and a second block is provided. The first block is a statistical copolymer comprising units of a 1,3-diene and more than 50 mol % of ethylene units. The second block is a polyethylene with a melting point above 90° C. and a number-average molar mass greater than or equal to 2000 g/mol and less than or equal to 10 000 g/mol. Such a diblock polymer has improved rheology compared to a statistical copolymer of the same microstructure and of the same macrostructure as the first block of the diblock polymer.

A diblock polymer composed of a first block and a second block is provided. The first block is a statistical copolymer comprising units of a 1,3-diene and more than 50 mol % of ethylene units. The second block is a polyethylene with a melting point above 90° C. and a number-average molar mass greater than or equal to 2000 g/mol and less than or equal to 10 000 g/mol. Such a diblock polymer has improved rheology compared to a statistical copolymer of the same microstructure and of the same macrostructure as the first block of the diblock polymer.