Methods of controlling molecular weight distribution of polymers and compositions thereof

• US 7,858,729 B2
• Filed: 05/29/2008
• Issued: 12/28/2010
• Est. Priority Date: 05/29/2008
• Status: Active Grant

• Current Assignee: Saudi Aramco Technologies Company
• Original Assignee: Novomer, Inc (Danimer Scientific, Inc.)
• Inventors: Allen, Scott D.
• Primary Examiner(s): Boykin; Terressa M
• Application Number:
  US12/129,106
• Publication Number:
  US 20090299032A1
• Time in Patent Office: 943 Days
• Field of Search: 502/102, 502/103, 502/117, 502/140, 502/150, 502/155, 502/160, 526/126, 526/127, 526/160, 526/161, 528/200
• US Class Current: 528/200
• CPC Class Codes: C08G 64/34 and cyclic ethers

Abstract

A catalyst, co-catalyst, and/or chain transfer agent is added at a time after initiation of an addition polymerization reaction to produce a polymer product with a widened molecular weight distribution relative to having all of the components in the original reaction mixture. The catalyst, co-catalyst, or chain transfer agent may be added discretely or continuously to the reaction to produce a product with a bimodal, trimodal, or other broadened molecular weight distribution.

Claims

1. A method of broadening a molecular weight distribution of a polymer product of an addition polymerization reaction comprising the steps of:

a) starting the addition polymerization reaction at a start time with monomer of the polymer product; and

b) adding at least one reaction component to the reaction during at least one reaction time after the start time;

wherein the reaction component is selected from the group consisting of;

i) at least one catalyst;

ii) at least one co-catalyst;

iii) at least one reversible chain transfer agent; and

iv) any combination of i), ii), and iii).

2. The method of claim 1, wherein the catalyst comprises at least one metal-based catalyst selected from the group consisting of:

A) an aluminum-based catalyst;

B) a manganese-based catalyst;

C) a chromium-based catalyst;

D) a cobalt-based catalyst;

E) a yttrium-based catalyst;

F) a zinc-based catalyst;

G) a cadmium-based catalyst;

H) a nickel-based catalyst; and

I) any combination of A) through H).

3. The method of claim 1, wherein the reaction component is added continuously to the reaction.

4. The method of claim 3, wherein a rate of continuous addition is varied with time.

5. The method of claim 1, wherein the product of the addition polymerization reaction is a polycarbonate.

6. The method of claim 5, wherein the addition polymerization is a co-polymerization of carbon dioxide and an epoxide.

7. The method of claim 6, wherein the addition polymerization is a co-polymerization of carbon dioxide and propylene oxide.

8. The method of claim 1, wherein the reaction component is added in one or more discrete steps to the reaction.

9. The method of claim 1, wherein the reaction component is added in a single step such that the molecular weight distribution of the product is bimodal.

10. The method of claim 1, wherein the reaction component is added in two steps such that the molecular weight distribution of the product is trimodal.

11. The method of claim 1 further comprising adding a chain termination agent prior to an end time when the reaction is stopped.

12. A product made by the method of claim 1.

13. A method of broadening a molecular weight distribution of a polycarbonate product of an addition polymerization reaction comprising the steps of:

a) starting the addition polymerization reaction at a start time with monomer of the polycarbonate product; and

b) adding at least one reaction component to the reaction during at least one reaction time after the start time.

14. The method of claim 13, wherein the reaction component is selected from the group consisting of:

i) at least one catalyst;

ii) at least one co-catalyst;

iii) at least one chain transfer agent; and

iv) any combination of i), ii), and iii).

15. The method of claim 14, wherein the catalyst comprises at least one metal-based catalyst selected from the group consisting of:

A) an aluminum-based catalyst;

B) a manganese-based catalyst;

C) a chromium-based catalyst;

D) a cobalt-based catalyst;

E) a yttrium-based catalyst;

F) a zinc-based catalyst;

G) a cadmium-based catalyst;

H) a nickel-based catalyst; and

I) any combination of A) through H).

16. The method of claim 13, wherein the reaction component is added continuously to the reaction.

17. The method of claim 16, wherein a rate of continuous addition is varied with time.

18. The method of claim 13, wherein the addition polymerization is a co-polymerization of carbon dioxide and an epoxide.

19. The method of claim 18, wherein the addition polymerization is a co-polymerization of carbon dioxide and propylene oxide.

20. The method of claim 13, wherein the reaction component is added in one or more discrete steps to the reaction.

21. The method of claim 13, wherein the reaction component is added in a single step such that the molecular weight distribution is bimodal.

22. The method of claim 13, wherein the reaction component is added in two steps such that the molecular weight distribution is trimodal.

23. A method of synthesizing a polymer product of an addition polymerization reaction having a predetermined molecular weight distribution, the method comprising the steps of:

a) determining an initial condition for the reaction;

b) calculating at least one addition amount of at least one reaction component to be added to the reaction during at least one reaction time after a start time for the reaction using at least one rate constant for the reaction;

c) starting the reaction with the initial condition at the start time; and

d) adding the addition amount of the reaction component to the reaction during the reaction time;

wherein the reaction component is selected from the group consisting of;

i) at least one catalyst;

ii) at least one co-catalyst;

iii) at least one reversible chain transfer agent; and

iv) any combination of i), ii), and iii).

24. The method of claim 23, wherein the catalyst comprises at least one metal-based catalyst selected from the group consisting of:

A) an aluminum-based catalyst;

B) a manganese-based catalyst;

C) a chromium-based catalyst;

D) a cobalt-based catalyst;

E) a yttrium-based catalyst;

F) a zinc-based catalyst;

G) a cadmium-based catalyst;

H) a nickel-based catalyst; and

I) any combination of A) through H).

25. The method of claim 23, wherein the reaction component is added continuously to the reaction.

26. The method of claim 23, wherein the product of the addition polymerization reaction is a polycarbonate.

27. The method of claim 26, wherein the addition polymerization is a co-polymerization of carbon dioxide and an epoxide.

28. The method of claim 27, wherein the addition polymerization is a co-polymerization of carbon dioxide and propylene oxide.

29. The method of claim 23, wherein the reaction component is added in one or more discrete steps to the reaction.

30. The method of claim 23, wherein the reaction component is added in a single step such that the molecular weight distribution is bimodal.

31. The method of claim 23, wherein the reaction component is added in two steps such that the molecular weight distribution is trimodal.

32. The method of claim 23 further comprising adding a chain termination agent prior to an end time when the reaction is stopped.