Long chain branched polymers and methods of making same
A polymer having a long chain branching content peaking at greater than about 20 long chain branches per million carbon atoms, and a polydispersity index of greater than about 10 wherein the long chain branching decreases to approximately zero at the higher molecular weight portion of the molecular weight distribution. A polymer having a long chain branching content peaking at greater than about 8 long chain branches per million carbon atoms, a polydispersity index of greater than about 20 wherein the long chain branching decreases to approximately zero at the higher molecular weight portion of the molecular weight distribution. A polymer having a long chain branching content peaking at greater than about 1 long chain branches per chain, and a polydispersity index of greater than about 10 wherein the long chain branching decreases to approximately zero at the higher molecular weight portion of the molecular weight distribution.
1. A polymer of C 2 -C 8 monoolefin monomers having a polydispersity index of greater than about 20 and a long chain branching content peaking at greater than about 8 long chain branches per million carbon atoms, wherein the long chain branching decreases to approximately zero at the higher molecular weight portion of the molecular weight distribution.
2. The polymer of claim 1 wherein the polymer comprises polyethylene.
3. The polymer of claim 1 wherein the long-chain branching content peaks at about 20 long chain branches per million carbon atoms.
4. The polymer of claim 1 wherein the long-chain branching content peaks at about 25 long chain branches per million carbon atoms.
5. The polymer of claim 1 wherein the long-chain branching content peaks at about 30 long chain branches per million carbon atoms.
6. The polymer of claim 1 wherein the long-chain branching content peaks at greater than about 1.0 long-chain branches per chain.
7. The polymer of claim 1 wherein the long-chain branching content peaks at greater than about 1.3 long-chain branches per chain.
8. The polymer of claim 1 wherein the long-chain branching content peaks at greater than about 1.5 long-chain branches per chain.
9. The polymer of claim 1 having a melt index of from about 0 dg/min to about 100 dg/min.
10. The polymer of claim 1 having a density of from about 0.90 g/cc to about 0.97 g/cc.
11. A method of polymerizing C 2 -C 8 monoolefin monomers comprising contacting the monomers with a chromium supported catalyst under conditions suitable for the formation of a polymer, and recovering the polymer;
wherein the chromium supported catalyst comprises a silica support having a surface area of less than about 200 m 2 /g; and
wherein the polymer has a polydispersity index of greater than about 20 and a long chain branching content peaking at greater than about 8 long chain branches per million carbon atoms, wherein the long chain branching decreases to approximately zero at the higher molecular weight portion of the molecular weight distribution.
12. The method of claim 11 wherein conditions suitable for formation of a polymer further comprises a cocatalyst.
13. The method of claim 11 wherein the chromium-supported catalyst further comprises titanium.
14. The method of claim 11 wherein the monomer comprises ethylene and the polymer comprises polyethylene.