In some embodiments, ethylene-propylene random copolymers as viscosity modifiers were synthesized with pyridyldiamido catalyst systems and a chain transfer agent. In some embodiments, the present disclosure provides for ethylene-propylene random copolymers having an ethylene content between about 45 wt % and about 55 wt %. In some embodiments, the ethylene-propylene random copolymer is used as a viscosity modifier in a lubricating composition and a fuel composition.

In some embodiments, ethylene-propylene random copolymers as viscosity modifiers were synthesized with pyridyldiamido catalyst systems and a chain transfer agent. In some embodiments, the present disclosure provides for ethylene-propylene random copolymers having an ethylene content between about 45 wt % and about 55 wt %. In some embodiments, the ethylene-propylene random copolymer is used as a viscosity modifier in a lubricating composition and a fuel composition.

Activators may comprise compounds represented by the Formula [Ar(EHR.sup.1R.sup.2)(OR.sup.3)]d+[M.sup.k+Q.sub.n].sup.d, wherein: Ar is an aryl group; E is nitrogen or phosphorous; R.sup.1 is a C.sub.1-C.sub.30, optionally substituted, linear alkyl group; R.sup.2 is a C.sub.1-C.sub.30, optionally substituted, linear alkyl group; R.sup.3 is a C.sub.10-C.sub.30, optionally substituted, linear alkyl group; M is an element selected from group 13 of the Periodic Table of the Elements; d is 1, 2 or 3; k is 1, 2, or 3; n is 1, 2, 3, 4, 5, or 6; n−k=d; and each Q is independently hydride, bridged or unbridged dialkylamido, halide, alkoxide, aryloxide, hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, or halosubstituted-hydrocarbyl radical. Catalysts systems may comprise these activators and methods of preparing polyolefins may use these catalysts systems.

Activators may comprise compounds represented by the Formula [Ar(EHR.sup.1R.sup.2)(OR.sup.3)]d+[M.sup.k+Q.sub.n].sup.d, wherein: Ar is an aryl group; E is nitrogen or phosphorous; R.sup.1 is a C.sub.1-C.sub.30, optionally substituted, linear alkyl group; R.sup.2 is a C.sub.1-C.sub.30, optionally substituted, linear alkyl group; R.sup.3 is a C.sub.10-C.sub.30, optionally substituted, linear alkyl group; M is an element selected from group 13 of the Periodic Table of the Elements; d is 1, 2 or 3; k is 1, 2, or 3; n is 1, 2, 3, 4, 5, or 6; n−k=d; and each Q is independently hydride, bridged or unbridged dialkylamido, halide, alkoxide, aryloxide, hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, or halosubstituted-hydrocarbyl radical. Catalysts systems may comprise these activators and methods of preparing polyolefins may use these catalysts systems.

In some embodiments, ethylene-propylene branched copolymers are synthesized with pyridyldiamido catalysts and a chain transfer agent, and their performance as viscosity modifiers in oil are detailed. In some embodiments, the present disclosure provides for ethylene-propylene branched copolymers having a shear thinning onset of less than about 0.01 rad/s and an HTHS value of less than about 3.3. In some embodiments, the ethylene-propylene branched copolymer is used as a viscosity modifier in a lubricating composition and a fuel composition.

In some embodiments, ethylene-propylene branched copolymers are synthesized with pyridyldiamido catalysts and a chain transfer agent, and their performance as viscosity modifiers in oil are detailed. In some embodiments, the present disclosure provides for ethylene-propylene branched copolymers having a shear thinning onset of less than about 0.01 rad/s and an HTHS value of less than about 3.3. In some embodiments, the ethylene-propylene branched copolymer is used as a viscosity modifier in a lubricating composition and a fuel composition.

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.

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.