Ethylene-propylene linear copolymers as viscosity modifiers

A method of polymerizing ethylene to produce at least one polyolefin composition, the method comprising

• (a) contacting ethylene and one or more C3 to C20 alpha-olefins with a catalyst system comprising an activator, a chain transfer agent, and a pyridyldiamido transition metal complex represented by the formula (A), (B), (C), or (D)
• wherein:
• M is a Group 3 or 4 metal;
• Q1 is a three atom bridge with the central of the three atoms being a group 15 or 16 element (said group 15 element may or may not be substituted with an R30 group) represented by the formula:
• -G1-G2-G3- where G2 is a group 15 or 16 atom (said group 15 element may be substituted with a R30 group), G1 and G3 are each a group 14, 15 or 16 atom (each group 14, 15 and 16 element may or may not be substituted with one or more R30 groups), where G1, G2 and G3, or G1 and G2, or G1 and G3, or G2 and G3 may form a singular or multi ring system;
• each R30 group is independently a hydrogen, a C1 to C100 hydrocarbyl radical, or a silyl radical;
• Q2 is —NR17 or —PR17, where R17 is a hydrocarbyl radical, a substituted hydrocarbyl radical, a silyl radical, or a germyl radical;
• Q3 is —(TT)— or —(TTT)— where each T is carbon or a heteroatom, and said carbon or heteroatom may be unsubstituted or substituted with one or more R30 groups that together with the “—C-Q3═C—” fragment, forms a 5- or 6-membered cyclic group or a polycyclic group including the 5- or 6-membered cyclic group;
• R1 is a hydrocarbyl radical, a substituted hydrocarbyl radical, or a silyl radical;
• each of R3, R4, and R5 is independently a hydrogen, a hydrocarbyl radical, a substituted hydrocarbyl radical, an aryl radical, a substituted aryl radical, an alkoxy radical, an aryloxy radical, a halogen, an amino radical, or a silyl radical, or two or more adjacent R3, R4, and R5 groups may independently join together to form a substituted or unsubstituted hydrocarbyl ring or heterocyclic ring, where the ring has 5, 6, 7, or 8 ring atoms and where substitutions on the ring can join to form additional rings;
• R2 is -E(R12)(R13)— where E is carbon, silicon, or germanium;
• Y is oxygen, sulfur, or -E*(R6)(R7)—, wherein E* is carbon, silicon, or germanium;
• each of R6, R7, R8, R9, R10, R11, R12, and R13 is independently a hydrogen, a hydrocarbyl radical, a substituted hydrocarbyl radical, an aryl radical, a substituted aryl radical, an alkoxy radical, a halogen, an amino radical, or a silyl radical, or two or more adjacent R6, R7, R8, R9, R10, R11, R12, and R13 groups may independently join together to form a saturated, substituted or unsubstituted hydrocarbyl ring or heterocyclic ring, where the ring has 5, 6, 7, or 8 ring carbon atoms and where substitutions on the ring can join to form additional rings;
• L is an anionic leaving group, where the L groups may be the same or different and any two L groups may be linked to form a dianionic leaving group;
• n is 1 or 2;
• L′ is neutral Lewis base;
• w is 0, 1, 2, 3 or 4;
• and
• (b) recovering a polyolefin composition comprising a random ethylene copolymer having an ethylene content of about 45 wt % to about 55 wt % based on the composition;
• and
• wherein the ethylene, the one or more C3 to C20 alpha-olefins, the activator, and the pyridyldiamido transition metal complex are contacted prior to addition of the chain transfer agent, wherein the method of polymerizing is performed in two stages with the chain transfer agent being introduced in the second stage and wherein the copolymer does not crystallize in the range from about −60° C. to about 30° C.