Polyethylenes with increased molecular weight distribution
Methods for making olefin polymerization catalysts and methods for making polyethylene polymers using the catalysts are provided. The polyethylenes can have a molecular weight distribution (MWD) of about 4.5 to about 14, a slope of strain hardening greater than about 0.75, and a melt flow ratio (MFR) greater than or equal to 8.33+(4.17×MWD).
1. A polyethylene comprising:
a molecular weight distribution (MWD) of about 4.5 to about 14;
a slope of strain hardening greater than about 0.75, as measured by extensional viscosity fixture (EVF); and
wherein the polyethylene has a heterogeneous distribution of short chain branching (SCB) and a melt flow ratio (I 21 /I 2 ) greater than or equal to 8.33+(4.17×MWD).
2. The polyethylene of claim 1 , wherein the polyethylene has a MWD of about 6.8 to about 14.
3. The polyethylene of claim 1 , wherein the polyethylene has a MWD of about 6.9 to about 14.
4. The polyethylene of claim 1 , wherein the polyethylene has a MWD of about 7.0 to about 14.
5. The polyethylene of claim 1 , wherein the polyethylene has a long chain branching (LCB) greater than about 0.01 per 1,000 carbon atoms and less than about 0.07 per 1,000 carbon atoms.
6. The polyethylene of claim 1 , wherein the polyethylene has a long chain branching (LCB) between about 0.05 and 0.06 per 1,000 carbon atoms.
7. The polyethylene of claim 1 , wherein the polyethylene has a long chain branching (LCB) having a length of 4 or more carbon atoms.
8. The polyethylene of claim 1 , wherein the polyethylene has a ratio of weight-average molecular weight calculated using an LS detector to weight-average molecular weight calculated using an RI detector, M w (LS)/M w (RI), of from about 1.4 to about 3.0.
9. The polyethylene of claim 1 , wherein the polyethylene has a ratio of weight-average molecular weight calculated using an LS detector to weight-average molecular weight calculated using an RI detector, M w (LS)/M w (RI), of from about 1.4 to about 2.8.
10. The polyethylene of claim 1 , wherein the polyethylene has a comonomer homogeneity index (CHI) of less than about 0.5.
11. The polyethylene of claim 1 , wherein the polyethylene has a melt flow ratio (I 21 /I 2 ) ranging from about 30 to about 60.
12. The polyethylene of claim 1 , wherein the polyethylene has a melt flow ratio (I 21 /I 2 ) ranging from about 45 to about 60.
13. The polyethylene of claim 1 , wherein the polyethylene has a density of from 0.91 g/cm 3 to about 0.965 g/cm 3 .
14. The polyethylene of claim 1 , wherein the polyethylene has a density greater than or equal to 0.945 g/cm 3 and a melt strength greater than or equal to a ×(3.7463×exp(−1.485×log(MI))), wherein a is equal to 1.5.
15. The polyethylene of claim 1 , wherein the polyethylene has a density greater than or equal to 0.945 g/cm 3 and a melt strength greater than or equal to a ×(3.7463×exp(−1.485×log(MI))), wherein a is equal to 1.75.
16. The polyethylene of claim 1 , wherein the polyethylene has a density greater than or equal to 0.945 g/cm 3 and a melt strength greater than or equal to a ×(3.7463×exp(−1.485×log(MI))), wherein a is equal to 1.9.
17. The polyethylene of claim 1 , wherein the polyethylene has a density less than or equal to 0.945 g/cm 3 and a melt strength greater than or equal to a ×(3.7463×exp(−1.485×log(M1))), wherein a is equal to 1.2.
18. The polyethylene of claim 1 , wherein the polyethylene has a density less than or equal to 0.945 g/cm 3 and a melt strength greater than or equal to a ×(3.7463×exp(−1.485×log(MI))), wherein a is equal to 1.5.
19. The polyethylene of claim 1 , wherein the polyethylene has a density less than or equal to 0.945 g/cm 3 and a melt strength greater than or equal to a ×(3.7463×exp(−1.485×log(MI))), wherein a is equal to 1.9.
20. The polyethylene of claim 1 , wherein the polyethylene is made using a catalyst that is free or essentially free from any electron donors or donor compounds.