Process for preparation of polyolefins via degenerative transfer polymerization

1. A method of producing a polyolefin composition comprising contacting a metallocene pre-catalyst with a substoichiometric amount of a co-catalyst; adding a first olefin monomer; and polymerizing by degenerative transfer polymerization said first monomer for a time sufficient to form said polyolefin, wherein said metallocene pre-catalyst has the formula:

wherein the dotted lines indicate a delocalized bond;

M is V, Nb or Ta;

each R 1 is independently hydrogen or alkyl or two adjacent R 1 form an aromatic ring;

each R 2 , R 3 and R 4 is independently alkyl, cycloalkyl, Si(alkyl) 3 , Si(aryl) 3 , phenyl, optionally substituted phenyl, or alkylphenyl; and

each R 5 is halo, alkyl, cycloalkyl, aryl or arylalkyl.

2. The method of claim 1 , wherein:

said optional substituents on phenyl are amino, hydroxy, alkoxy, amide, aryl, alkyl, halo, ketone, ester, —SO 3 H, aldehyde, carboxylic acid, cyano, nitro and ammonium.

3. The method of claim 1 , wherein said co-catalyst has one of the formulae:

[A] + [BR 6 4 ] ⊖ or BR 6 3

wherein A + is Si(R 7 ) 3 , a cationic Lewis acid or a cationic Brønsted acid;

B is the element boron;

R 6 is phenyl or a phenyl optionally substituted by alkoxy, amide, aryl, alkyl, halo, ketone, ester, —SO 3 H, aldehyde, carboxylic acid, cyano, nitro and ammonium;

each R 7 is independently selected from alkyl and optionally substituted phenyl.

4. The method of claim 3 , wherein said co-catalyst is [PhNMe 2 H][B(C 6 F 5 ) 4 ] or Si(CH 2 CH 3 ) 3 [B(C 6 F 5 ) 4 ].

5. The method of claim 1 , wherein said metallocene pre-catalyst and said co-catalyst are contacted in a metallocene pre-catalyst:co-catalyst ratio of about 1.2:1-100:1.

6. The method of claim 5 , wherein said metallocene pre-catalyst and said co-catalyst are contacted in a metallocene pre-catalyst:co-catalyst ratio of about 2:1.

7. The method of claim 1 , wherein said co-catalyst is added in an amount of about 1-5 mole % of said metallocene pre-catalyst.

8. The method of claim 1 , wherein said metallocene pre-catalyst is contacted with a substoichiometric amount of a co-catalyst in an inert solvent.

9. The method of claim 8 , wherein said solvent is chlorobenzene, dichlorobenzene, isopentane, hexane, cyclohexane, heptane, benzene, toluene, trifluorotoluene, pentane, octane, isooctane or dichloromethane.

10. The method of claim 1 , wherein said metallocene pre-catalyst and said co-catalyst are contacted at a temperature of about −20° C. to about 10° C.

11. The method of claim 1 , wherein said first olefin monomer is ethene, propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, styrene, alpha-methyl styrene, butadiene, isoprene, acrylonitrile, methyl acrylate, methyl methacrylate, vinyl acetate, vinyl chloride, vinyl fluoride, vinylidene chloride, N-vinyl pyrrolidone, 3-methylbutene, 3-methyl-1-pentene, vinylcyclohexane, vinylcyclobutane, vinylcyclopentane, vinylcyclooctane, 1-decene, enantiomerically pure β-citronellene, 3,5,5-trimethyl-1-hexene or 4-methyl-1-pentene.

12. The method of claim 1 , wherein said first olefin monomer is a non-conjugated diene having the formula:

wherein X=CH 2 , CO, N(R 13 ), O or S;

R 11 , R 12 and R 13 are each independently H, alkyl or phenyl; and

n and m are each independently an integer from 0-5.

13. The method of claim 1 , wherein said first olefin monomer is 1,4-pentadiene, 1,5-hexadiene, 5-vinyl-2-norbornene, 1,7-octadiene, vinylcyclohexene, dicyclopentadiene, butadiene, isobutylene, isoprene or ethylidene norbomene.

14. The method of claim 1 , wherein said metallocene pre-catalyst and said first olefin monomer are added in a metallocene pre-catalvst:first monomer ratio of about 1:10-1:10,000.

15. The method of claim 14 , wherein said ratio is about 1:10.

16. The method of claim 14 , wherein said ratio is about 1:100.

17. The method of claim 14 , wherein said ratio is about 1:1000.

18. The method of claim 1 , further comprising contacting said polyolefin with a second amount of said co-catalyst; adding a second olefin monomer; and polymerizing said second olefin monomer to form a block-polyolefin composition.

19. The method of claim 18 , wherein said second amount of co-catalyst is about a stoichiometric amount or more of said metallocene pre-catalyst.

20. The method of claim 18 , wherein said second amount is a metallocene pre-catalyst:co-catalyst ratio of about 0.5:1-2:1.

21. The method of claim 18 , wherein said metallocene pre-catalyst and said second olefin monomer are added in a metallocene pre-catalyst:second monomer ratio of about 1:10-1:10,000.

22. The method of claim 21 , wherein said ratio is about 1:10.

23. The method of claim 21 , wherein said ratio is about 1:100.

24. The method of claim 21 , wherein said ratio is about 1:1000.

25. The method of claim 18 , wherein said first olefin and second olefin are independently ethene, propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, styrene, alpha-methyl styrene, butadiene, isoprene, acrylonitrile, methyl acrylate, methyl methacrylate, vinyl acetate, vinyl chloride, vinyl fluoride, vinylidene chloride, N-vinyl pyrrolidone, 3-methylbutene, 3-methyl-1-pentene, vinylcyclohexane, vinylcyclobutane, vinylcyclopentane, vinylcyclooctane, 1-decene, enantiomerically pure β-citronellene, 3,5,5-trimethyl-1-hexene or 4-methyl-1-pentene.

26. The method of claim 18 , wherein said first olefin monomer and said second olefin monomer are independently non-conjugated dienes having the formula:

wherein X=CH 2 , CO, N(R 13 ), O or S;

R 11 , R 12 and R 13 are each independently H, alkyl or phenyl; and

n and m are each independently an integer 0-5.

27. The method of claim 25 , wherein said first olefin and said second olefin are the same.

28. The method of claim 18 , wherein said polyolefin is an atactic living polyolefin.

29. The method of claim 18 , wherein said block-polyolefin composition comprises a diblock copolymer having the formula: atactic-poly(first olefin)-b-isotactic-poly(second olefin).

30. The method of claim 29 , wherein said atactic-poly(first olefin) block has degree of polymerization about equal to said isotactic-poly(second olefin) block.

31. The method of claim 29 , wherein said diblock copolymer composition has polydispersity about 1.02-1.1.

32. The method of claim 31 , wherein said polydispersity is about 1.05.

33. The method of claim 29 , wherein said diblock copolymer is monomodal.

34. The method of claim 1 , wherein said polyolefin is an isotactic polyolefin having polydispersity index of about 1.02-1.1.

35. The method of claim 1 , wherein said contacting said metallocene pre-catalyst with said substoichiometric amount of said co-catalyst comprises forming an active metallocene catalyst; and said polymerizing by degenerative transfer comprises reacting said first monomer with said active metallocene catalyst to form an active propagating center.

36. The method of claim 35 , wherein said polymerizing by degenerative transfer further comprises reacting said propagating center with said metallocene pre-catalyst to form a dormant chain and an active metallocene catalyst.

37. The method of claim 36 , wherein said reacting comprises transferring a methyl group from said metallocene pre-catalyst to said active propagating center to form said active metallocene catalyst and said dormant chain.

38. The method of claim 36 , wherein said polymerizing by degenerative transfer further comprises transferring a methyl group between said active propagating center and said dormant chain.

39. A method of producing a polyolefin composition comprising contacting a metallocene pre-catalyst with a co-catalyst and an olefin; and polymerizing said olefin by degenerative transfer Ziegler-Natta polymerization, wherein said metallocene has the formula:

wherein each R 1 is independently hydrogen or alkyl or two adjacent R 1 form an aromatic ring;

each R 2 and R 3 is independently alkyl, cycloalkyl, Si(alkyl) 3 , Si(aryl) 3 , phenyl, optionally substituted phenyl, or alkylphenyl; and

each R 5 is halo, alkyl, cycloalkyl, aryl or arylalkyl.

40. The method of claim 39 , wherein said metallocene pre-catalyst has the formula: