Ethylene-a-olefin-diene elastomers and methods of making them
A process to produce a branched ethylene-α-olefin diene elastomer comprising combining a catalyst precursor and an activator with a feed comprising ethylene, C3 to C12 α-olefins, and a dual-polymerizable diene to obtain a branched ethylene-α-olefin diene elastomer; where the catalyst precursor is selected from pyridyldiamide and quinolinyldiamido transition metal complexes. The branched ethylene-α-olefin diene elastomer may comprise within a range from 40 to 80 wt % of ethylene-derived units by weight of the branched ethylene-α-olefin diene elastomer, and 0.1 to 2 wt % of singly-polymerizable diene derived units, 0.1 to 2 wt % of singly-polymerizable diene derived units, and the remainder comprising C3 to C12 α-olefin derived units, wherein the branched ethylene-α-olefin diene elastomer has a weight average molecular weight (M w ) within a range from 100 kg/mole to 300 kg/mole, an average branching index (g′ avg ) of 0.9 or more, and a branching index at very high M w (g′ 1000 ) of less than 0.9.
1. A process to produce a branched ethylene-α-olefin diene elastomer (b-EDE) comprising combining a catalyst precursor and an activator with a feed comprising ethylene, C 3 to C 12 α-olefins, and a dual-polymerizable diene to obtain a b-EDE; where the catalyst precursor is selected from pyridyldiamide and quinolinyldiamido transition metal complexes, wherein the pyridyldiamido and quinolinyldiamido transition metal complexes are selected from one of the following structures:
wherein M is titanium, hafnium or zirconium;
R 1 and R 10 are independently selected from the group consisting of hydrocarbyls, substituted hydrocarbyls, heterohydrocarbyls, and silyl groups;
R 2 and R 9 are each, independently, divalent hydrocarbyls or a chemical bond;
R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 are independently selected from the group consisting of hydrogen, hydrocarbyls, substituted hydrocarbyls, alkoxy, aryloxy, halogen, amino, and silyl, and wherein adjacent R groups may be joined to form a substituted or unsubstituted hydrocarbyl 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;
X is an anionic leaving group, where the X groups may be the same or different and any two X groups may be linked to form a dianionic leaving group; and
Z is —(R 11 ) p QJ(R 12 ) q —, wherein Q is carbon, oxygen, nitrogen, or silicon, and where J is carbon or silicon, p is 1 or 2; and q is 1 or 2; and R 11 and R 12 are independently selected from the group consisting of hydrogen, hydrocarbyls, and substituted hydrocarbyls, and wherein adjacent R 11 and R 12 groups may be joined to form an aromatic or saturated, substituted or unsubstituted hydrocarbyl 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.
2. The process of claim 1 , combining at a temperature within a range from 80° C. to 160° C. and a pressure within a range from 0.5 MPa to 8 MPa.
3. The process of claim 1 , combining in a solution process.
4. The process of claim 1 , also combining a singly-polymerizable diene.
5. The process of claim 1 , wherein the α-olefins comprise propylene.
6. The process of claim 1 , wherein hydrogen is present to less than 5 sccm (standard cubic centimeter per min.).
7. The process of claim 4 , wherein the b-EDE comprises within a range from 40 to 80 wt % of ethylene-derived units by weight of the b-EDE, 0.05 to 2 wt % of the dual-polymerizable diene derived units by weight of the b-EDE, and 0 to 15 wt % of the singly-polymerizable diene derived units by weight of the b-EDE, the remainder comprising C 3 to C 12 α-olefin derived units.
8. The process of claim 1 , wherein the b-EDE has a weight average molecular weight (Mw) within a range from 100 kg/mole to 750 kg/mole.
9. The process of claim 1 , wherein the b-EDE has a g′ avg of 0.9 or more, and a g′ 1000 of less than 0.9.
10. A process to produce a branched ethylene-α-olefin diene elastomer (b-EDE) comprising combining a catalyst precursor and an activator with a feed comprising ethylene, C 3 to C 12 α-olefins, and a dual-polymerizable diene to obtain a b-EDE; where the catalyst precursor is selected from pyridyldiamide and quinolinyldiamido transition metal complexes, wherein the catalyst precursor is a transition metal complex selected from one of the following structures:
wherein the “Me” represents methyl and “iPr” represents iso-propyl.
11. A process to produce a branched ethylene-α-olefin diene elastomer (b-EDE) comprising combining a catalyst precursor and an activator with a feed comprising ethylene, C 3 to C 12 α-olefins, and a dual-polymerizable diene to obtain a b-EDE; where the catalyst precursor is selected from pyridyldiamide and quinolinyldiamido transition metal complexes, wherein the catalyst precursor is a transition metal complex selected from one of the following structures:
wherein the R1 and R2 are any C 1 to C 10 alkyl (normal, iso, and/or tertiary).