Methods for modulated degenerative transfer living polymerization and isotactic-atactic stereoblock and stereogradient poly(olefins) thereby
Methods for modulated degenerative transfer living polymerization and isotactic-atactic stereoblock and stereogradient poly(olefins) thereby Abstract A method of producing a multiblock, stereoblock polyolefin having substantially uniform microstructure is disclosed. The method includes contacting a Ziegler-Natta pre-catalyst with a co-catalyst and an olefin to polymerize the olefin and form a first stereoblock, adding a methyl donator that changes the stereoregularity of the polymerization, and polymerizing the olefin to form a second stereoblock. The methods of the present invention allow for the production of poly(olefin)s having predictable degrees of incorporation of stereoerrors of a known type. The methods allows for the production of a variety of poly(olefin) microstructures, ranging from stereoblock to stereogradient poly(olefin)s and poly(olefin)s having fully isotactic to fully atactic microstructures.
1. A composition comprising an elastomeric isotactic-atactic multiblock stereoblock poly(olefin) having substantially uniform microstructure, wherein the multiblock is a triblock, tetrablock, pentablock, hexablock, heptablock, octablock, nonablock, or decablock.
2. The composition of claim 1 , wherein said poly(olefin) is a poly(olefin) of propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, styrene, alpha-methyl styrene, 3-methylbutene, 3-methyl-1-pentene, vinylcyclohexane, vinylcyclobutane, vinylcyclopentane, vinylcyclooctane,1-decene, enantiomerically pure β-citronellene, 3,5,5-trimethyl-1-hexene, 4-methyl-1-pentene; a non-conjugated diene having the formula:
wherein X is CH 2 , CO, N(R 13 ), O or S;
R 12 and R 13 are independently H, alkyl or phenyl; and
n and m are each independently an integer from 0-5; or mixtures thereof.
3. The composition of claim 1 , wherein said poly(olefin) is poly(propylene).
4. The composition of claim 3 , wherein the block length for each stereoblock of said isotactic-atactic poly(olefin) is the substantially same for all polymer chains.
5. The composition of claim 3 , wherein said poly(propylene) is a monomodal elastomeric isotactic-atactic poly(propylene) having a substantially uniform microstructure.
6. The poly(propylene) of claim 5 , wherein said poly(propylene) has polydispersity index of about 1.07 to about 1.25.
7. The poly(propylene) of claim 5 , further comprising a number average molecular weight of about 18,300 to about 5,000,000.
8. The poly(propylene) of claim 5 , having an ultimate elongation to break of about 1000 to about 1500%.
9. The poly(propylene) of claim 8 , having a residual elongation of less than about 5% after a strain of about 150 to about 250%.
10. The poly(propylene) of claim 5 , having a single melting point and a single crystallization point.
11. The poly(propylene) of claim 5 , comprising isotactic poly(propylene) content in the range of about 10 to about 40%.
12. The poly(propylene) of claim 5 , wherein said isotactic stereoblocks have (mmmm) pentad ratio of about 0.70 to about 0.75.
13. The poly(propylene) of claim 5 , wherein said poly(propylene) exhibits microphase separation on the nanometer scale.
14. The poly(propylene) of claim 5 , comprising monomodal isotactic-atactic-isotactic poly(propylene) having a substantially uniform microstructure.
15. The poly(propylene) of claim 14 , wherein each poly(propylene) chain independently has the formula:
wherein g, h and i are independently an integer between 0 and 10,000; and
the polydispersity of said poly(propylene) chains is about 1.07 to about 1.25.
16. The composition of claim 1 , wherein said isotactic-atactic poly(olefin) comprises about 10-40% isotactic poly(olefin).
17. The composition of claim 1 , wherein said poly(olefin) has number average molecular weight greater than about 18,300.
18. The composition of claim 17 , wherein said poly(olefin) has number average molecular weight of about 18,300 to about 5,000,000.
19. The composition of claim 1 , wherein said poly(olefin) has monomodal molecular weight distribution.
20. The composition of claim 1 , wherein said poly(olefin) has polydispersity index in the range of about 1.07 to about 1.25.
21. The composition of claim 1 , wherein said isotactic stereoblock has (mmmm) pentad ratio in the range of about 0.70 to about 1.0.
22. The composition of claim 21 , wherein said isotactic stereoblock has less than about 0.5% stereoerrors.
23. The composition of claim 22 , wherein said isotactic stereoblock has about 0.1 to about 0.5% (2,1)-misinsertions.
24. The composition of claim 1 , further comprising an isotactic-atactic triblock, tetrablock, pentablock, hexablock, heptablock, octablock, nonablock or decablock stereoblock poly(olefin) microstructure.
25. The composition of claim 1 , further comprising an isotactic-atactic-isotactic triblock stereoblock poly(olefin).
26. The composition of claim 25 , wherein said poly(olefin) is isotactic-atactic-isotactic triblock stereoblock poly(propylene).
27. The composition of claim 25 , wherein each poly(olefin) chain independently has the formula:
wherein g, h and i are independently zero or an integer between 1 and 10,000;
R 10 , R 11 and R 15 are independently alkyl, cycloalkyl or optionally substituted phenyl; and
the polydispersity of said poly(olefin) composition is about 1.07 to about 1.25.
28. The composition of claim 1 , wherein said isotactic and atactic stereoblocks comprise different poly(olefin)s.
29. The composition of claim 1 , wherein said poly(olefin) exhibits microphase separation in the solid state.
30. The composition of claim 29 , wherein said poly(olefin) exhibits microphase separation on the nanometer scale.
31. The composition of claim 1 , wherein said elastomeric isotactic-atactic stereoblock poly(olefin) has substantially uniform and stereogradient microstructure.
32. A composition comprising isotactic-atactic stereogradient poly(olefin) having uniform microstructure, wherein said stereogradient poly(olefin) is a triblock, tetrablock, pentablock, hexablock, heptablock, octablock, nonablock, or decablock stereogradient poly,(olefin).
33. Tne composition of claim 32 , wherein said poly(olefin) is poly(propylene).
34. The composition of claim 32 , wherein said isotactic-atactic stereogradient microstructure comprises a mmmm pentad transition from greater than about 0.7 to less than about 0.5 over a fixed length of chiral centers.
35. The composition of claim 34 , wherein said isotactic-atactic stereogradient microstructure comprises a mmmm pentad transition from greater than about 0.7 to less than about 0.3 over a fixed length of chiral centers.