Polycarbonate polyol compositions and methods
In one aspect, the present disclosure encompasses polymerization systems for the copolymerization of CO 2 and epoxides comprising 1) a catalyst including a metal coordination compound having a permanent ligand set and at least one ligand that is a polymerization initiator, and 2) a chain transfer agent having two or more sites that can initiate polymerization. In a second aspect, the present disclosure encompasses methods for the synthesis of polycarbonate polyols using the inventive polymerization systems. In a third aspect, the present disclosure encompasses polycarbonate polyol compositions characterized in that the polymer chains have a high percentage of —OH end groups and a high percentage of carbonate linkages. The compositions are further characterized in that they contain polymer chains having an embedded polyfunctional moiety linked to a plurality of individual polycarbonate chains.
1. A polycarbonate polyol composition comprising polymer chains denoted P 1 having the formula T-Y-A-(Y-T) n wherein:
each -T is a polycarbonate chain having a formula independently selected from the group consisting of:
wherein:
E is an optionally substituted C 2 unit derived from an epoxide, where E may represent a monomer unit derived from one type of epoxide, or a mixture of two or more types of epoxide, and
p ranges from about 5 to about 10,000,
each —Y-A-(Y—) n derives from a chain transfer agent where each —Y group is independently a functional group capable of initiating chain growth of epoxide CO 2 copolymers and each Y group may be the same or different,
-A- is a polyolefin chain or an optionally substituted C 3-20 aliphatic chain; and
n is an integer between 1 and 10 inclusive.
2. The polycarbonate polyol composition of claim 1 , further comprising polymer chains denoted P 2 having a formula selected from the group consisting of:
wherein
X is a bound form of an anion capable of initiating only one polymer chain.
3. The polycarbonate polyol composition of claim 2 , wherein the ratio of P 1 polymer chains to P 2 polymer chains is greater than 20:1.
4. The polycarbonate polyol composition of claim 2 , wherein ratio of P 1 polymer chains to P 2 polymer chains is greater than 40:1.
5. The polycarbonate polyol composition of claim 2 , wherein ratio of P 1 polymer chains to P 2 polymer chains is greater than 100:1.
6. The polycarbonate polyol composition of claim 1 , wherein n is 1.
7. The polycarbonate polyol composition of claim 1 , wherein chains of type P 1 have the formula:
8. The polycarbonate polyol composition of claim 7 , wherein -A- is an optionally substituted C 3-20 aliphatic chain.
9. The polycarbonate polyol composition of claim 1 , wherein chains of type P 1 have the formula:
where each z is 1.
10. The polycarbonate polyol composition of claim 9 , wherein -A- is an optionally substituted C 3-20 aliphatic chain.
11. The polycarbonate polyol composition of claim 1 , wherein the chain transfer agent is a diol, triol, or tetraol.
12. The polycarbonate polyol composition of claim 11 , wherein -A- is an optionally substituted C 3-20 aliphatic chain.
13. The polycarbonate polyol composition of claim 11 , wherein the chain transfer agent is an α-ω diol comprising an optionally substituted C 3-20 aliphatic chain.
14. The polycarbonate polyol composition of claim 13 , wherein the chain transfer agent is selected from 1,8-octanediol, 1,10-decanediol, and 1,12-dodecanediol.
15. The polycarbonate polyol composition of claim 11 , wherein the chain transfer agent is a hydroxyl-terminated polyolefin.
16. The polycarbonate polyol composition of claim 15 , wherein the chain transfer agent is selected from a hydroxyl-terminated polybutadiene, a hydroxyl-terminated polyisobutylene, and a hydroxyl-terminated polybutadienestyrene.
17. The polycarbonate polyol composition of claim 16 , wherein the chain transfer agent is selected from Krasol®, Polytail® H, or Polytail® HA.
18. The polycarbonate polyol composition of claim 1 , wherein the chain transfer agent is a diacid, triacid, or tetracid or a salt thereof.
19. The polycarbonate polyol composition of claim 18 , wherein -A- is an optionally substituted C 3-20 aliphatic chain.
20. The polycarbonate polyol composition of claim 18 , wherein the chain transfer agent is selected from pimelic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid.
21. The polycarbonate polyol composition of claim 18 , wherein the chain transfer agent is a carboxy-terminated polyolefin.
22. The polycarbonate polyol composition of claim 21 , wherein the chain transfer agent is selected from a NISSO-PB C-series resin.
23. The polycarbonate polyol composition of claim 1 , wherein the chain transfer agent is a hydroxyacid or a salt thereof.
24. The polycarbonate polyol composition of claim 23 , wherein -A- is an optionally substituted C 3-20 aliphatic chain.
25. The polycarbonate polyol composition of claim 23 , wherein the chain transfer agent is an α-ω hydroxy acid comprising an optionally substituted C 3-20 aliphatic chain.
26. The polycarbonate polyol composition of claim 25 , wherein the chain transfer agent is 7-hydroxyheptanoic acid, 9-hydroxynonanoic acid, 10-hydroxydecanoic acid, or 12-hydroxydodecanoic acid.
27. The polycarbonate polyol composition of claim 1 , wherein the chain transfer agent is an amino alcohol.
28. The polycarbonate polyol composition of claim 27 , wherein -A- is an optionally substituted C 3-20 aliphatic chain.
29. The polycarbonate polyol composition of claim 1 , characterized in that the polycarbonate polyol has a Mn between 400 and 20,000 and greater than 95% of the polymer end groups are hydroxyl groups.