Polyethylene extrudates and methods of making the same

1. A polymer cable-coating and/or a wire-coating comprising a bimodal polyethylene comprising at least 80 mol % ethylene and at least one C 3 -C 20 olefin comonomer; a high molecular weight portion having a weight average molecular weight (M w ) of 100,000 g/mol to 1,000,000 g/mol; and a low molecular weight portion having a M w of 10,000 g/mol to 80,000 g/mol, wherein the bimodal polyethylene has:

(i) a density of 0.880 g/cm 3 to 0.960 g/cm 3 ;

(ii) a melt index (I 2 ) of 0.10 g/10 min to 20 g/10 min;

(iii) a melt index ratio (I 21 /I 2 ) (MIR) of 40 to 200;

(iv) a shear thinning index (SHI*) (at 0.1 rad/s)≤0.70 or a SHI* (at 2.0 rad/s)≤0.30;

(v) a percentage hot set ≤80%; and

(vi) a M w ≤200,000 g/mol.

2. The polymer cable-coating and/or a wire-coating of claim 1 , wherein the bimodal polyethylene has a molecular weight distribution (M w /M n ) of 3 to 30.

3. The polymer cable-coating and/or a wire-coating of claim 1 , wherein the bimodal polyethylene has one or more of the following:

(i) a density of 0.900 g/cm 3 to 0.950 g/cm 3 ;

(ii) a melt index (I 2 ) of 0.10 g/10 min to 10 g/10 min;

(iii) a melt index ratio (I 21 /I 2 ) (MIR) of 60 to 200;

(iv) a shear thinning index (SHI*) (at 0.1 rad/s)≤0.60 or a SHI* (at 2.0 rad/s)≤0.20;

(v) a percentage hot set ≤70%

(vi) a high load melt index (I 21 ) of 45 g/10 min to 250 g/10 min;

(vii) a complex viscosity (measured at 400 rad/s and 220° C.)≤550 Pa. s; and

(viii) a shear viscosity (measured at a die wall shear rate of 7,000 s −1 and 220° C.)≤70 Pa·s.

4. The polymer cable-coating and/or a wire-coating of claim 1 , wherein:

at a molecular weight range of 10,000 to 500,000 g/mol, the bimodal polyethylene has an orthogonal comonomer distribution; and

at a molecular weight range of 500,000 to 2,000,000 g/mol the bimodal polyethylene has a comonomer distribution with decreasing comonomer content.

5. The polymer cable-coating and/or a wire-coating of claim 1 , wherein the high molecular weight portion of the polyethylene bimodal is present in an amount of ≤50 wt % and the low molecular weight portion is present is an amount of ≥50 wt %, based on total weight of the bimodal polyethylene.

6. A method for preparing the polymer cable-coating and/or a wire-coating of claim 1 comprising:

contacting ethylene and at least one C 3 -C 20 olefin comonomer with a mixed catalyst in a single reactor to produce the bimodal polyethylene: and

extruding the bimodal polyethylene at an apparent die wall shear rate ≥500 s −1 and a melt temperature ≤250° C. to form the polymer cable-coating and/or wire-coating.

7. The method of claim 6 , wherein the shear rate is ≥1000 s −1 and/or the melt temperature is ≤220° C.

8. The method of claim 6 , wherein the mixed catalyst comprises: (i) a metallocene catalyst and a non-metallocene catalyst; (ii) a metallocene catalyst and a single-site catalyst; (iii) a non-metallocene catalyst and a single-site catalyst; (iv) two metallocene catalysts; (v) two non-metallocene catalysts; or (vi) two single-site catalysts.

9. A polymer cable-coating and/or a wire-coating produced according to the method of claim 6 .

10. A polymer film comprising a bimodal polyethylene comprising at least 80 mol % ethylene and at least one C 3 -C 20 olefin comonomer; a high molecular weight portion having a weight average molecular weight (M w ) of 100,000 g/mol to 1,000,000 g/mol; and a low molecular weight portion having a M w of 10,000 g/mol to 80,000 g/mol; wherein the bimodal polyethylene has:

(i) a density of 0.880 g/cm 3 to 0.940 g/cm 3 ;

(ii) a melt index (I 2 ) of 0.10 g/10 min to 10 g/10 min; and

(iii) a melt index ratio (I 21 /I 2 ) (MIR) of 40 to 200; and

(iv) a M w ≤200,000 g/mol;

and wherein the polymer film has:

(i) a 1% secant modulus (MD or TD) >32,000 psi; and

(ii) an Elmendorf Tear (MD or TD) of 40 g to 1000 g.

11. The polymer film of claim 10 , wherein the bimodal polyethylene has a molecular weight distribution (M w /M n ) of 3 to 30.

12. The polymer film of claim 10 , wherein the bimodal polyethylene has one or more of:

(i) a density of 0.900 g/cm 3 to 0.940 g/cm 3 ;

(ii) a melt index (I 2 ) of 0.10 g/min to 5.0 g/min;

(iii) a melt index ratio (I 21 /I 2 ) (MIR) of 60 to 200;

(iv) a melt strength of at least 4 cN;

(v) a melt elasticity (G′) of ≥1000 Pa; and

(vi) a high load melt index (I 21 ) of 45 g/10 min to 150 g/10 min; and

wherein the polymer film has one or more of:

(i) a 1% secant modulus (MD or TD) ≥34,000 psi;

(ii) an Elmendorf Tear (MD or TD) of 45 g to 900 g;

(iii) a film gel count (>200 μm particles) <30 ppm;

(iv) a dart drop impact ≥70 g; and

(v) an elongation at break (MD or TD) ≥350%.

13. The polymer film of claim 10 , wherein:

at a molecular weight range of 10,000 to 500,000 g/mol, the bimodal polyethylene has an orthogonal comonomer distribution; and

at a molecular weight range of 500,000 to 2,000,000 g/mol the bimodal polyethylene has a comonomer distribution with decreasing comonomer content.

14. The polymer film of claim 10 , wherein the high molecular weight portion is present in an amount of ≤50 wt % and the low molecular weight portion is present is an amount of ≥50 wt %, based on total weight of the bimodal polyethylene composition.

15. A method for preparing the polymer film of claim 10 comprising:

contacting ethylene and at least one C 3 -C 20 olefin comonomer with a mixed catalyst in a single reactor to produce the bimodal polyethylene; and

extruding the bimodal polyethylene at a die pressure ≤2900 psi and a motor load ≤70 amps to form the polymer film.

16. The method of claim 15 , wherein the die pressure is ≤2500 psi and the motor load is ≤60 amps.

17. The method of claim 15 , wherein the mixed catalyst comprises a metallocene catalyst and a non-metallocene catalyst.

18. A polymer film produced according to the method of claim 15 .