Modified supported chromium catalysts and ethylene-based polymers produced therefrom
Supported chromium catalysts with an average valence less than +6 and having a hydrocarbon-containing or halogenated hydrocarbon-containing ligand attached to at least one bonding site on the chromium are disclosed, as well as ethylene-based polymers with terminal alkane, aromatic, or halogenated hydrocarbon chain ends. Another ethylene polymer characterized by at least 2 wt. % of the polymer having a molecular weight greater than 1,000,000 g/mol and at least 1.5 wt. % of the polymer having a molecular weight less than 1000 g/mol is provided, as well as an ethylene homopolymer with at least 3.5 methyl short chain branches and less than 0.6 butyl short chain branches per 1000 total carbon atoms.
1. An ethylene homopolymer having:
a number of methyl short chain branches (SCB's) in a range from about 3.5 to about 15 per 1000 total carbon atoms;
a number of butyl short chain branches (SCB's) of less than or equal to about 0.6 per 1000 total carbon atoms; and
a ratio of Mw/Mn in a range from about 4 to about 10.
2. The homopolymer of claim 1 , wherein the homopolymer has:
a ratio of Mz/Mw in a range from about 2.5 to about 7;
a Mw in a range from about 30,000 to about 200,000 g/mol; and
a density in a range from about 0.93 to about 0.96 g/cm 3 .
3. The homopolymer of claim 1 , wherein:
the number of methyl SCB's is in a range from about 5 to about 10 per 1000 total carbon atoms;
the number of butyl SCB's is less than or equal to about 0.2 per 1000 total carbon atoms; and
the ratio of Mw/Mn is in a range from about 4.5 to about 8.5.
4. The homopolymer of claim 3 , wherein the homopolymer has:
a ratio of Mz/Mw in a range from about 3 to about 6;
a Mw in a range from about 40,000 to about 135,000 g/mol; and
a density in a range from about 0.935 to about 0.955 g/cm 3 .
5. The homopolymer of claim 1 , wherein the homopolymer has a number of ethyl SCB's in a range from about 0.8 to about 5 per 1000 total carbon atoms.
6. The homopolymer of claim 1 , wherein the homopolymer has a ratio of vinyl chain ends to saturated chain ends per 1000 total carbon atoms of less than or equal to about 0.3.
7. The homopolymer of claim 1 , wherein the homopolymer contains less than 0.1 ppm by weight of nickel, iron, titanium, zirconium, or hafnium.
8. An article comprising the homopolymer of claim 1 .
9. The homopolymer of claim 1 , wherein the homopolymer has:
a ratio of Mz/Mw in a range from about 2.5 to about 7;
a Mw in a range from about 30,000 to about 200,000 g/mol;
a density in a range from about 0.93 to about 0.96 g/cm 3 ; or
any combination thereof.
10. The homopolymer of claim 9 , wherein:
the number of methyl SCB's is in a range from about 5 to about 10 per 1000 total carbon atoms;
the number of butyl SCB's is less than or equal to about 0.2 per 1000 total carbon atoms;
the ratio of Mw/Mn is in a range from about 4.5 to about 8.5; or
any combination thereof.
11. The homopolymer of claim 9 , wherein the homopolymer has a number of ethyl SCB's in a range from about 0.8 to about 5 per 1000 total carbon atoms.
12. The homopolymer of claim 9 , wherein the homopolymer has a ratio of vinyl chain ends to saturated chain ends per 1000 total carbon atoms of less than or equal to about 0.3.
13. The homopolymer of claim 9 , wherein the homopolymer contains less than 0.1 ppm by weight of nickel, iron, titanium, zirconium, or hafnium.
14. An article comprising the homopolymer of claim 9 .
15. The homopolymer of claim 1 , wherein the homopolymer has:
a ratio of Mz/Mw in a range from about 3 to about 6;
a Mw in a range from about 40,000 to about 135,000 g/mol;
a density in a range from about 0.935 to about 0.955 g/cm 3 ; or
any combination thereof.
16. The homopolymer of claim 15 , wherein:
the number of methyl SCB's is in a range from about 5 to about 10 per 1000 total carbon atoms;
the number of butyl SCB's is less than or equal to about 0.2 per 1000 total carbon atoms;
the ratio of Mw/Mn is in a range from about 4.5 to about 8.5; or
any combination thereof.
17. The homopolymer of claim 15 , wherein the homopolymer has a number of ethyl SCB's in a range from about 0.8 to about 5 per 1000 total carbon atoms.
18. The homopolymer of claim 15 , wherein the homopolymer has a ratio of vinyl chain ends to saturated chain ends per 1000 total carbon atoms of less than or equal to about 0.3.
19. The homopolymer of claim 15 , wherein the homopolymer contains less than 0.1 ppm by weight of nickel, iron, titanium, zirconium, or hafnium.
20. An article comprising the homopolymer of claim 15 .