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 is an olefin-based rubber composition having low hardness, good thermal conductivity, and good electrical insulation, and applying little load on a manufacturing facility. The olefin-based rubber composition of the present disclosure contains an ethylene-α-olefin-nonconjugated polyene copolymer, at least two types of magnesium carbonate which are small-particle size magnesium carbonate with 0.3 to 5 μm of an average particle size and large-particle size magnesium carbonate with 7-60 μm of an average particle size, and a cross-linking agent, wherein the composition contains 400 to 1200 parts by mass of a total content of the two types of magnesium carbonate per 100 parts by mass of the ethylene-α-olefin-nonconjugated polyene copolymer, Shore A hardness conforming to JIS K 6253-3 : 2012 of the olefin-based rubber composition after cross-linking is 80, and thermal conductivity conforming to ASTM D7984 of the olefin-based rubber composition after cross-linking is 2.0 W/m.Math.K or more.

Provided is an olefin-based rubber composition having low hardness, good thermal conductivity, and good electrical insulation, and applying little load on a manufacturing facility. The olefin-based rubber composition of the present disclosure contains an ethylene-α-olefin-nonconjugated polyene copolymer, at least two types of magnesium carbonate which are small-particle size magnesium carbonate with 0.3 to 5 μm of an average particle size and large-particle size magnesium carbonate with 7-60 μm of an average particle size, and a cross-linking agent, wherein the composition contains 400 to 1200 parts by mass of a total content of the two types of magnesium carbonate per 100 parts by mass of the ethylene-α-olefin-nonconjugated polyene copolymer, Shore A hardness conforming to JIS K 6253-3 : 2012 of the olefin-based rubber composition after cross-linking is 80, and thermal conductivity conforming to ASTM D7984 of the olefin-based rubber composition after cross-linking is 2.0 W/m.Math.K or more.

Embodiments of this disclosure are directed to ethylene-based polymers. The ethylene-based polymer are polymerized units derived from ethylene, diene, and optionally, one or more C3-C12 α-olefins. The ethylene-based polymer includes a melt viscosity ratio (V0.1/V100) at 190 C greater than 20. The V0.1 is the viscosity of the ethylene-based polymer at 190 C at a frequency of 0.1 radians/second, and the V100 is the viscosity of the ethylene-based polymer at 190 C at a frequency of 100 radians/second. Additionally, the ethylene-based polymer includes an average g greater than 0.86, where the average g′ is an intrinsic viscosity ratio determined by gel permeation chromatography using a triple detector.

Embodiments of this disclosure are directed to ethylene-based polymers. The ethylene-based polymer are polymerized units derived from ethylene, diene, and optionally, one or more C3-C12 α-olefins. The ethylene-based polymer includes a melt viscosity ratio (V0.1/V100) at 190 C greater than 20. The V0.1 is the viscosity of the ethylene-based polymer at 190 C at a frequency of 0.1 radians/second, and the V100 is the viscosity of the ethylene-based polymer at 190 C at a frequency of 100 radians/second. Additionally, the ethylene-based polymer includes an average g greater than 0.86, where the average g′ is an intrinsic viscosity ratio determined by gel permeation chromatography using a triple detector.

Embodiments of this disclosure are directed to ethylene-based polymers. The ethylene-based polymer are polymerized units derived from ethylene, diene, and optionally, one or more C3-C12 α-olefins. The ethylene-based polymer includes a melt viscosity ratio (V0.1/V100) at 190 C greater than 20. The V0.1 is the viscosity of the ethylene-based polymer at 190 C at a frequency of 0.1 radians/second, and the V100 is the viscosity of the ethylene-based polymer at 190 C at a frequency of 100 radians/second. Additionally, the ethylene-based polymer includes an average g greater than 0.86, where the average g′ is an intrinsic viscosity ratio determined by gel permeation chromatography using a triple detector.

The ethylene-based polymers include a low molecular weight polymer fraction and a high molecular weight polymer fraction, which are divided by S.sub.max on a molecular weight distribution (MWD) curve determined via absolute gel permeation chromatography. The low molecular weight polymer fraction and the high molecular weight polymer fraction include a Ladder character, L, defined for a given absolute molecular weight (MW) as the fit of the log of the intrinsic viscosity [h] versus the log of the absolute MW (M) curve using the expression, log[η]=log(β)+α log(M)−L*α log(2) according to a Mark-Houwink-Sakurada curve, in which log(β) is the intercept and ax is the slope. The low molecular weight polymer fraction has an MW below S.sub.max and all values of L between −0.35 to 0.35; and the high molecular weight polymer fraction has an MW above S.sub.max and a maximum value of L between 0.8 and 1.5.

The ethylene-based polymers include a low molecular weight polymer fraction and a high molecular weight polymer fraction, which are divided by S.sub.max on a molecular weight distribution (MWD) curve determined via absolute gel permeation chromatography. The low molecular weight polymer fraction and the high molecular weight polymer fraction include a Ladder character, L, defined for a given absolute molecular weight (MW) as the fit of the log of the intrinsic viscosity [h] versus the log of the absolute MW (M) curve using the expression, log[η]=log(β)+α log(M)−L*α log(2) according to a Mark-Houwink-Sakurada curve, in which log(β) is the intercept and ax is the slope. The low molecular weight polymer fraction has an MW below S.sub.max and all values of L between −0.35 to 0.35; and the high molecular weight polymer fraction has an MW above S.sub.max and a maximum value of L between 0.8 and 1.5.

The ethylene-based polymers include a low molecular weight polymer fraction and a high molecular weight polymer fraction, which are divided by S.sub.max on a molecular weight distribution (MWD) curve determined via absolute gel permeation chromatography. The low molecular weight polymer fraction and the high molecular weight polymer fraction include a Ladder character, L, defined for a given absolute molecular weight (MW) as the fit of the log of the intrinsic viscosity [h] versus the log of the absolute MW (M) curve using the expression, log[η]=log(β)+α log(M)−L*α log(2) according to a Mark-Houwink-Sakurada curve, in which log(β) is the intercept and ax is the slope. The low molecular weight polymer fraction has an MW below S.sub.max and all values of L between −0.35 to 0.35; and the high molecular weight polymer fraction has an MW above S.sub.max and a maximum value of L between 0.8 and 1.5.

The disclosure are directed to a process for polymerizing ethylene-based polymers. The process includes polymerizing ethylene and optionally one or more (C.sub.3-C.sub.14)α-olefin monomer, and at least one diene, in the presence of at least one multi-chain catalyst and at least one single-chain catalyst. The process may include a solvent. The multi-chain catalyst in the process includes a plurality of polymerization sites. Long-chain branched polymers are synthesized by connecting the two polymer chains of the multi-chain catalyst with the diene, the joining of the two polymer chains being performed in a concerted manner during the polymerization. The ethylene-based polymers are produced and include at least two molecular weight polymer fractions. The multi-chain catalyst produces the high molecular weight fraction, which is the long-chain branched polymer.