Univation Technologies, LLC

Methods described herein are directed to decreasing triboelectric charging of, and/or reactor fouling by, polyolefin particles, the methods comprising: feeding an argon gas/nitrogen gas mixture upward through the distributor plate into the reaction zone to fluidize the polyolefin particles in the reaction zone, wherein the argon gas/nitrogen gas mixture consists of from 5 volume percent (vol %) to no more than 65 vol % argon gas, from 95 vol % to no less than 10 vol % nitrogen gas, and from 0 vol % to no more than 5 vol % helium gas, wherein the sum of all these vol % equals 100 vol % of the argon gas/nitrogen gas mixture.

A unimodal ethylene-co-1-butene copolymer that, when in melted form at 190 degrees Celsius, is characterized by a unique melt property space defined by combination of shear thinning and melt elasticity properties. A blown film consisting essentially of the unimodal ethylene-co-1-butene copolymer. A method of synthesizing the unimodal ethylene-co-1-butene copolymer. A method of making the blown film. A manufactured article comprising the unimodal ethylene-co-1-butene copolymer.

According to one embodiment, a process for producing unimodal ethylene/α-olefin copolymer, the process comprising contacting ethylene and, optionally, one or more (C 3 -C 12 )α-olefin comonomers with a catalyst system in a gas-phase polymerization reactor, wherein the catalyst system comprises a chromium-based catalyst; wherein the unimodal ethylene copolymer comprises: a density from 0.942 g/cm 3 to 0.950 g/cm 3 according to ASTM D792-13; a flow index (I 21 ) from 5.5 to 7.5 dg/min, when measured according to ASTM D1238 at 190° C. and a 21.6 kg load; a strain hardening modulus of 40 to 50 MPa; and a molecular weight distribution (MWD) as determined by a conventional gel permeation chromatography method or absolute gel permeation chromatography.

A method of independently changing a melt rheology property value of a bimodal polyethylene polymer being made using a bimodal catalyst system in a single gas phase polymerization reactor. The method comprises process conditions comprising alkane(s) in the reactor. The method comprises a bimodal catalyst system that is characterized by an inverse response to alkane(s) concentration. The method comprises changing concentration of the alkane(s) in the reactor by an amount sufficient to effect a measurable change in the melt rheology property value; wherein the bimodal catalyst system is characterized by an inverse response to alkane(s) concentration such that when the alkane(s) concentration is increased, the melt rheology property value of the resulting bimodal polyethylene polymer is decreased, and when the alkane(s) concentration is decreased, the melt rheology property value of the resulting bimodal polyethylene polymer is increased.

A unimodal ethylene-co-1-butene copolymer that, when in melted form at 190 degrees Celsius, is characterized by a unique melt property space defined by combination of shear thinning and melt elasticity properties. A blown film consisting essentially of the unimodal ethylene-co-1-butene copolymer. A method of synthesizing the unimodal ethylene-co-1-butene copolymer. A method of making the blown film. A manufactured article comprising the unimodal ethylene-co-1-butene copolymer.

Embodiments are directed towards methods of making binodal polyethylenes, wherein the methods include a plurality of cycles of ratio adjustments.

According to one embodiment, a process for producing a unimodal ethylene/α-olefin copolymer, the process comprising contacting ethylene and one or more (C 3 -C 12 ) α-olefin comonomers with a chromium-based catalyst system in a gas-phase polymerization reactor to produce the unimodal ethylene/α-olefin copolymer; wherein the unimodal ethylene/α-olefin copolymer comprises: a density from 0.952 g/cm 3 to 0.957 g/cm 3 ; a flow index (I 21 ) from 4.0 to 6.2 dg/min; a melt viscosity ratio (V 0.1 /V 100 ) at 190° C. of 55 to 75; a molecular weight distribution (MWD) as calculated by the weight average molecular weight (M w ) divided by the number-average molecular weight (M n ) (M w /M n ); and a peak molecular weight (M p ), all as measured by gel permeation chromatography.

Disclosed herein is a method for polymerizing a compound in a gas phase reactor. The method includes at least passing a liquid catalyst to a catalyst inlet of a manifold assembly, passing a carrier gas to a carrier gas inlet of the manifold assembly, combining the liquid catalyst and the carrier gas in the main channel of the manifold assembly, and passing the combination of the liquid catalyst and the carrier gas to the reaction chamber. The present disclosure is also directed to manifold assemblies for communication with reaction chambers.

A unimodal ethylene-co-1-hexene copolymer that, when in melted form at 190 degrees Celsius, is characterized by a unique melt property space defined by combination of melt elasticity and complex viscosity ratio (shear thinning) properties. A blown film consisting essentially of the unimodal ethylene-co-1-hexene copolymer. A method of synthesizing the unimodal ethylene-co-hexene copolymer. A method of making the blown film. A manufactured article comprising the unimodal ethylene-co-1-hexene copolymer.

A method of independently changing a melt rheology property value of a bimodal polyethylene polymer being made using a bimodal catalyst system in a single gas phase polymerization reactor. The method comprises process conditions comprising alkane(s) in the reactor. The method comprises a bimodal catalyst system that is characterized by an inverse response to alkane(s) concentration. The method comprises changing concentration of the alkane(s) in the reactor by an amount sufficient to effect a measurable change in the melt rheology property value; wherein the bimodal catalyst system is characterized by an inverse response to alkane(s) concentration such that when the alkane(s) concentration is increased, the melt rheology property value of the resulting bimodal polyethylene polymer is decreased, and when the alkane(s) concentration is decreased, the melt rheology property value of the resulting bimodal polyethylene polymer is increased.