Polycarbonates made using highly selective catalysts

• US 20070255039A1
• Filed: 06/15/2007
• Published: 11/01/2007
• Est. Priority Date: 10/08/2004
• Status: Active Grant

• Current Assignee: Cornell Research Foundation Incorporated (Cornell University)
• Original Assignee: Cornell Research Foundation Incorporated (Cornell University)
• Inventors: Qin, Zengquan, Cohen, Claire, Coates, Geoffrey
• Granted Patent: US 7,674,873 B2
• Time in Patent Office: Days
• US Class Current: 528/392
• CPC Class Codes: B01J 2231/14 Other (co) polymerisation, e.g. of lactides, epoxides "ROMP", i.e. ring-opening metathesis polymerisation B01J2231/54
• CPC Class Codes: B01J 2531/0252 Salen ligands or analogues, e.g. derived from ethylenediamine and salicylaldehyde
• CPC Class Codes: B01J 2531/845 Cobalt
• CPC Class Codes: B01J 31/1805 the ligands containing nitrogen
• CPC Class Codes: C07F 15/065 without a metal-carbon linkage

Abstract

Poly(propylene carbonates) are prepared from propylene oxide and CO₂ with less than 10% cyclic propylene carbonate by product using cobalt based catalysts of structure
preferably in combination with salt cocatalyst, very preferably cocatalyst where the cation is PPN⁺ and the anion is Cl⁻ or OBzF₅⁻. Novel products include poly(propylene carbonates) having a stereoregularity greater than 90% and/or a regioregularity of greater than 90%.

Claims

1-4. -4. (canceled)

5. A catalyst system for epoxide/CO₂ copolymerization comprising as a catalyst

6. The catalyst system of claim 5 where the cocatalyst is a salt where the cation is:

7. The catalyst system of claim 6 where the catalyst has the structural formula (VIII) where X is OBzF₅ and the cocatalyst is PPNCl.

8. The catalyst system of claim 6 where the catalyst has the structural formula (VIII) where X is Cl and the cocatalyst is [PPN][BzF₅].

9. The catalyst system of claim 6 where the catalyst has the structural formula (VIII) where X is Cl and the cocatalyst is [PPN]Cl.

10. The catalyst system of claim 6 where the cocatalyst is NBu₄Cl and the catalyst has the structural formula (VIII) where X is OBzF₅.

11. The catalyst system of claim 6, the catalyst has the structural formula (XI) where R¹⁰ and R¹¹ are CPh(CH₃)₂ and the cocatalyst is [PPN]Cl.

12-18. -18. (canceled)

19. Poly(propylene carbonate) of M_n ranging from 1,000 to 1,000,000 g/mol and PDI ranging from 1.05 to 5.0 with greater than 90% head-to-tail linkages.

20. The poly(propylene carbonate) of claim 19 which has random stereochemistry.

21. The poly(propylene carbonate),of claim 19 where more than 90% of adjacent stereocenters have the same relative stereochemistry.

22. The poly(propylene carbonate) of claim 19 where more than 60% of adjacent stereocenters have the opposite relative stereochemistry 23. Poly(propylene carbonate) of M_n ranging from 1,000 to 1,000,000 g/mol and PDI ranging from 1.05 to 5.0 where greater than 90% of the stereocenters are of the same stereochemistry.

24. (canceled)