Polycarbonate polyol compositions and methods

Abstract

In one aspect, the present disclosure encompasses polymerization systems for the copolymerization of CO.sub.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.

Claims

1. A polycarbonate polyol composition comprising an epoxide CO.sub.2 copolymer, characterized in that the copolymer has: an Mn between about 1,000 and about 3,000 g/mol; and greater than 99% carbonate linkages; wherein the composition comprises epoxide CO.sub.2 copolymer chains denoted P.sup.1 that: (i) have the formula: ##STR00106## wherein each E comprises predominantly —CH.sub.2CH(CH.sub.3)— units derived from propylene oxide; p ranges from 5 to 10,000; and -A- is a polyether; or (ii) are derived from a diol chain transfer agent selected from a polyether; and wherein the composition is characterized in that more than 99% of the epoxide CO.sub.2 copolymer chains are of type P.sup.1.

2. The polycarbonate polyol composition of claim 1, further comprising epoxide CO.sub.2 copolymer chains denoted P.sup.2 having a formula selected from the group consisting of: ##STR00107## wherein X is a bound form of an anion capable of initiating only one polymer chain; wherein the ratio of P.sup.1 polymer chains to P.sup.2 polymer chains is greater than 100:1.

3. The polycarbonate polyol composition of claim 2, characterized in that the copolymer has an Mn of about 1,000 g/mol, about 2,000 g/mol, or about 3,000 g/mol.

4. The polycarbonate polyol composition of claim 3, wherein the composition comprises epoxide CO.sub.2 copolymer chains denoted P.sup.1 that have the formula: ##STR00108## wherein each E comprises predominantly —CH.sub.2CH(CH.sub.3)— units derived from propylene oxide; p ranges from 5 to 10,000; and -A- is a polyether.

5. The polycarbonate polyol composition of claim 4, wherein the chains of type P.sub.1 are derived from a diol chain transfer agent selected from a poly(propylene glycol) having a Mn from 234 to 2,000 g/mol.

6. The polycarbonate polyol composition of claim 4, characterized in that: the polydispersity index is less than about 1.1; and more than 99% of linkages between adjacent epoxide monomer units are head-to-tail linkages.

7. The polycarbonate polyol composition of claim 5, characterized in that: the polydispersity index is less than about 1.1; and more than 99% of linkages between adjacent epoxide monomer units are head-to-tail linkages.

8. A method for the synthesis of a polycarbonate polyol composition of claim 1, the method comprising the step of: a) providing a reaction mixture comprising: (i) propylene oxide; (ii) carbon dioxide; (iii) a metallosalenate metal complex; and (iv) a chain transfer agent selected from a poly(propylene glycol) having a Mn from 234 to 2,000 g/mol; b) allowing the polymerization reaction to proceed; and c) terminating the polymerization.

9. The method of claim 8, wherein the chain transfer agent and metal complex are present in a molar ratio ranging of greater than 1000:1.

10. A polycarbonate polyol composition comprising an epoxide CO.sub.2 copolymer, characterized in that the copolymer has: an Mn between about 400 and about 4,000 g/mol; and greater than 99% carbonate linkages; wherein the composition comprises epoxide CO.sub.2 copolymer chains denoted P.sup.1 that: (i) have the formula: ##STR00109## wherein each E comprises predominantly —CH.sub.2CH(CH.sub.3)— units derived from propylene oxide; p ranges from 5 to 10,000; and A- is ##STR00110## (mixture isomers); or (ii) are derived from a diol chain transfer agent selected from dipropylene glycol; and wherein the composition is characterized in that more than 99% of the epoxide CO.sub.2 copolymer chains are of type P.sup.1.

11. The polycarbonate polyol composition of claim 10, further comprising epoxide CO.sub.2 copolymer chains denoted P.sup.2 having a formula selected from the group consisting of: ##STR00111## wherein X is a bound form of an anion capable of initiating only one polymer chain; wherein the ratio of P.sup.1 polymer chains to P.sup.2 polymer chains is greater than 100:1.

12. The polycarbonate polyol composition of claim 11, characterized in that the copolymer has an Mn of about 1,000 g/mol, about 2,000 g/mol, or about 3,000 g/mol.

13. The polycarbonate polyol composition of claim 12, wherein the composition comprises epoxide CO.sub.2 copolymer chains denoted P.sup.1 that have the formula: ##STR00112## wherein each E comprises predominantly —CH.sub.2CH(CH.sub.3)— units derived from propylene oxide; p ranges from 5 to 10,000; and -A- is ##STR00113## (mixture isomers).

14. The polycarbonate polyol composition of claim 12, wherein the chains of type P.sup.1 are derived from a diol chain transfer agent selected from dipropylene glycol.

15. The polycarbonate polyol composition of claim 13, characterized in that: the polydispersity index is less than about 1.1; and more than 99% of linkages between adjacent epoxide monomer units are head-to-tail linkages.

16. The polycarbonate polyol composition of claim 14, characterized in that: the polydispersity index is less than about 1.1; and more than 99% of linkages between adjacent epoxide monomer units are head-to-tail linkages.

17. A method for the synthesis of a polycarbonate polyol composition of claim 10, the method comprising the step of: a) providing a reaction mixture comprising: (i) propylene oxide; (ii) carbon dioxide; (iii) a metallosalenate metal complex; and (iv) a chain transfer agent selected from a dipropylene glycol; wherein the chain transfer agent and metal complex are present in a molar ratio ranging of greater than 1000:1; b) allowing the polymerization reaction to proceed; and c) terminating the polymerization.

18. A polycarbonate polyol composition comprising an epoxide CO.sub.2 copolymer, characterized in that the copolymer has: an Mn between about 800 and about 4,000; and greater than 99% carbonate linkages; wherein the composition comprises epoxide CO.sub.2 copolymer chains denoted P.sup.1 that: (i) have the formula: ##STR00114## wherein each z is independently 0 or 1; each E comprises predominantly —CH.sub.2CH(CH.sub.3)— units derived from propylene oxide; p ranges from 5 to 10,000; and A- is a polyether; or (ii) are derived from a diol chain transfer agent selected from polypropylene oxide triol; and wherein the composition is characterized in that more than 99% of the epoxide CO.sub.2 copolymer chains are of type P.sup.1.

19. The polycarbonate polyol composition of claim 18, further comprising epoxide CO.sub.2 copolymer chains denoted P.sup.2 having a formula selected from the group consisting of: ##STR00115## wherein X is a bound form of an anion capable of initiating only one polymer chain; wherein the ratio of P.sup.1 polymer chains to P.sup.2 polymer chains is greater than 100:1.

20. The polycarbonate polyol composition of claim 19, characterized in that the copolymer has an Mn of about 1,000 g/mol, about 2,000 g/mol, or about 3,000 g/mol.

21. The polycarbonate polyol composition of claim 20, wherein the composition comprises epoxide CO.sub.2 copolymer chains denoted P.sup.1 that have the formula: ##STR00116## wherein each z is independently 0 or 1; each E comprises predominantly —CH.sub.2CH(CH.sub.3)— units derived from propylene oxide; p ranges from 5 to 10,000; and -A- is a polyether.

22. The polycarbonate polyol composition of claim 20, wherein the chains of type P.sup.1 are derived from a diol chain transfer agent selected from polypropylene oxide triol.

23. A method for the synthesis of a polycarbonate polyol composition of claim 18, the method comprising the step of: a) providing a reaction mixture comprising: (i) propylene oxide; (ii) carbon dioxide; (iii) a metallosalenate metal complex; and (iv) a chain transfer agent selected from a polypropylene oxide triol; b) allowing the polymerization reaction to proceed; and c) terminating the polymerization.

24. The method of claim 23, wherein the chain transfer agent and metal complex are present in a molar ratio ranging of greater than 1000:1.

Description

EXAMPLES

Example 1

(1) This example demonstrates the use of the polymerization system of the present invention with a chain transfer agent Y-A-(Y).sub.n and a catalyst L-M-(L.sub.I).sub.m utilizing a co-catalyst PPN+ Cl—, where n is 1, each —Y is —OH, -A- is

(2) ##STR00068## -L.sub.p is a salcy ligand

(3) ##STR00069## -M- is Co(III), -L.sub.I is a chain transfer agent -Q′-A′(Z′).sub.n, where Q′ is COO.sup.−, -A- is —CH.sub.2—, and Z′ is —OH, and

(4) n is 1.

(5) 24 mg of catalyst E1 (0.04 mmol), 0.45 g (3.1 mmol) 1,4-cyclohexanedimethanol and 20 mg (0.04 mmol) PPN.sup.+Cl.sup.− were held under vacuum in a Fisher-Potter bottle. The bottle was filled with nitrogen and 20 ml propylene

(6) ##STR00070##
oxide was added. The bottle was pressurized with 100 psi CO.sub.2. After 41 h at 30° C. the bottle was opened and the polymer was isolated by pouring into methanol. GPC analysis showed formation of a polymer of M.sub.n=4460, M.sub.w=4610, PDI=1.035. The polymer has a carbonate content of >97%.

(7) The polycarbonate polyol composition thus obtained consists predominantly of three types of polymer chains: chains P.sup.1 arising from initiation by the cyclohexanedimethanol, chains P.sup.1′ arising from initiation by the glycolic acid (L.sub.I) and chains P.sup.2 arising from the chloride counterion on the PPN co-catalyst:

(8) ##STR00071##
where each p is on average approximately 20-21. In this particular composition, the ratio of P.sup.1 to P.sup.1′ to P.sup.2 is approximately 89:1:1. The polycarbonate polyol composition contains approximately 99% OH end groups.

Example 2

(9) This example demonstrates the use of the polymerization system of the present invention with a chain transfer agent Y-A-(Y).sub.n and a catalyst L.sub.p-M-(L.sub.I).sub.m utilizing a co-catalyst PPN+ Cl—, where n is 3, each —Y is —OH, -A- is

(10) ##STR00072## -L.sub.p is a salcy ligand

(11) ##STR00073## -M- is Co(III), and -L.sub.I is trifluoroacetate.

(12) ##STR00074##

(13) 51 mg of catalyst E2 (0.07 mmol), 0.5 g (1.4 mmol) of propoxylated pentaerythritol and 41 mg (0.08 mmol) PPN.sup.+Cl.sup.− were held under vacuum in a Fisher-Potter bottle. F.sub.3 E-2 The bottle was filled with nitrogen and 20 ml propylene oxide was added. The bottle was pressurized with 100 psi CO.sub.2. After 22 h at 30° C. the bottle was opened and the polymer was isolated by pouring into methanol. GPC analysis showed formation of a polymer formation of a polymer of M.sub.n=13660, M.sub.w=15420, PDI=1.129. The polymer has a carbonate content of >97%.

(14) The polycarbonate polyol composition thus obtained consists predominantly of three types of polymer chains: chains p.sup.1a arising from initiation by the propoxylated pentaerythritol, chains P.sup.2a arising from initiation by the trifluoroacetate (L.sub.I) and chains P.sup.2 arising from the chloride counterion on the PPN co-catalyst:

(15) ##STR00075##
where each p is on average approximately 30-32. In this particular composition, the ratio of P.sup.1n to P.sup.2n to P.sup.2 is approximately 20:1:1. The polycarbonate polyol composition contains approximately 97% OH end groups.

Example 3

(16) Example 3 was conducted using conditions similar to Example 2, except Poly(caprolactone) diol having an Mn of 530 g/mol was used as the chain transfer agent.

Example 4

(17) Example 4 was conducted using conditions similar to Example 3, except Poly(ethylene glycol) having an Mn of 400 g/mol was used as the chain transfer agent.

Example 5

(18) Example 5 was conducted using conditions similar to Example 3, except Poly(propylene glycol) having an Mn of 760 g/mol was used as the chain transfer agent.

Example 6

(19) Example 6 was conducted using conditions similar to Example 3, except 1,2-cyclohexane diol was used as the chain transfer agent.

Example 7

(20) This example demonstrates the use of the polymerization system of the present invention with a chain transfer agent Y-A-(Y).sub.n and a catalyst L.sub.p-M-(L.sub.I).sub.m utilizing a co-catalyst PPN+ Cl—, where n is 1, each —Y is —OH, -A- is

(21) ##STR00076## -L.sub.p is a salcy ligand

(22) ##STR00077## -M- is Co(III), and -L.sub.I is trifluoroacetate.

(23) An oven dried glass vessel was charged with 11.5 mg of catalyst E2 (0.016 mmol) and 9.2 mg of PPN.sup.+Cl.sup.− (0.016 mmol). The vessel was purged with nitrogen and 1,4 butane diol (0.073 g, 0.8 mmol) was added as a solution in dry THF (0.5 mL). Propylene oxide (4.5 mL, 64 mmol) was then added. The reaction vessel was pressurized with 300 psig dry carbon dioxide gas and stirred at 30° C. for 3 hours. The reaction was quenched with acid, diluted with 25 mL acetone and concentrated to yield 2.6 g of crude polymer. The polymer had an Mn of 4072 g/mol, and a PDI of 1.04. The polymer contained no detectable ether linkages and had greater than 98% —OH end groups.

(24) The polycarbonate polyol composition thus obtained consists predominantly of three types of polymer chains: chains P.sup.1a arising from initiation by the 1,4 butanediol, chains P.sup.2a arising from initiation by the trifluoroacetate (L.sub.I) and chains P.sup.2 arising from the chloride counterion on the PPN co-catalyst:

(25) ##STR00078##
where each p is on average approximately 20.

(26) In this particular composition, the ratio of P.sup.1a to P.sup.2a to P.sup.2 is approximately 50:1:1.

Example 8

(27) This example demonstrates the use of the polymerization system of the present invention with a chain transfer agent Y-A-(Y).sub.n and a catalyst L.sub.I-M-(L.sub.I).sub.m utilizing a co-catalyst PPN+ Cl—, where n is 1, each —Y is —OH, -A- is

(28) ##STR00079## -L.sub.p is a salcy ligand

(29) ##STR00080## -M- is Co(III), and -L.sub.I is trifluoroacetate.

(30) An oven dried glass vessel was charged with 11.5 mg of catalyst E2 (0.016 mmol) and 9.2 mg of PPN.sup.+Cl.sup.− (0.016 mmol). The vessel was purged with nitrogen and 1,4 propane diol (0.061 g, 0.8 mmol) was added as a solution in dry THF (0.5 mL). Propylene oxide (4.5 mL, 64 mmol) was then added. The reaction vessel was pressurized with 300 psig dry carbon dioxide gas and stirred at 30° C. for 3× hours. The reaction was quenched with acid, diluted with 25 mL acetone and concentrated to yield 2.7 g of crude polymer. The polymer had an Mn of 4336 g/mol, and a PDI of 1.04. The polymer contained no detectable ether linkages and had greater than 98% —OH end groups.

(31) The polycarbonate polyol composition thus obtained consists predominantly of three types of polymer chains: chains P.sup.1a arising from initiation by the 1,3 propanediol, chains P.sup.2a arising from initiation by the trifluoroacetate (L.sub.I) and chains P.sup.2 arising from the chloride counterion on the PPN co-catalyst:

(32) ##STR00081##
where each p is on average approximately 21.

(33) In this particular composition, the ratio of P.sup.1a to P.sup.2a to P.sup.2 is approximately 50:1:1.

Example 9

(34) This example demonstrates the use of the polymerization system of the present invention with a chain transfer agent Y-A-(Y).sub.n and a catalyst L.sub.p-M-(L.sub.I).sub.m utilizing a co-catalyst PPN+ Cl—, where n is 1, each —Y is —OH, -A- is

(35) ##STR00082## -L.sub.p is a salcy ligand

(36) ##STR00083## -M- is Co(III), and -L.sub.I is trifluoroacetate.

(37) An oven dried glass vessel was charged with 11.5 mg of catalyst E2 (0.016 mmol) and 9.2 mg of PPN.sup.+ Cl.sup.− (0.016 mmol). The vessel was purged with nitrogen and 1,4 butene diol (0.079 g, 0.8 mmol) was added as a solution in dry THF (0.5 mL). Propylene oxide (4.5 mL, 64 mmol) was then added. The reaction vessel was pressurized with 300 psig dry carbon dioxide gas and stirred at 30° C. for 3 hours. The reaction was quenched with acid, diluted with 25 mL acetone and concentrated to yield 1.5 g of crude polymer. The polymer had an Mn of 2431 g/mol, and a PDI of 1.06. The polymer contained no detectable ether linkages and had greater than 98% —OH end groups.

(38) The polycarbonate polyol composition thus obtained consists predominantly of three types of polymer chains: chains P.sup.1a arising from initiation by the 1,4 butenediol, chains P.sup.2a arising from initiation by the trifluoroacetate (L.sub.I) and chains P.sup.2 arising from the chloride counterion on the PPN co-catalyst:

(39) ##STR00084##
where each p is on average approximately 12. In this particular composition, the ratio of P.sup.1a to P.sup.2a to P.sup.2 is approximately 50:1:1.

Example 10

(40) This example demonstrates the use of the polymerization system of the present invention with a chain transfer agent Y-A-(Y).sub.n and a catalyst L.sub.p-M-(L.sub.I).sub.m utilizing a co-catalyst PPN+ Cl—, where n is 1, each —Y is —CO.sub.2H, -A- is

(41) ##STR00085## -L.sub.p is a salcy ligand

(42) ##STR00086## -M- is Co(III), and -L.sub.I is trifluoroacetate.

(43) An oven dried glass vessel was charged with 11.5 mg of catalyst E2 (0.016 mmol); 9.2 mg of PPN.sup.+Cl.sup.− (0.016 mmol); succinic acid (0.095 g, 0.8 mmol) and 0.5 mL THF. Propylene oxide (4.5 mL, 64 mmol) was then added. The reaction vessel was pressurized with 300 psig dry carbon dioxide gas and stirred at 30° C. for 3 hours. The reaction was quenched with acid, diluted with 25 mL acetone and concentrated to yield 3.0 g of crude polymer. The polymer had an Mn of 13,933 g/mol, and a PDI of 1.04. The polymer contained no detectable ether linkages and had greater than 98% —OH end groups.

(44) The polycarbonate polyol composition thus obtained consists predominantly of three types of polymer chains: chains P.sup.1a arising from initiation by the succinic acid, chains P.sup.2a arising from initiation by the trifluoroacetate (L.sub.I) and chains P.sup.2 arising from the chloride counterion on the PPN co-catalyst:

(45) ##STR00087##
where each p is on average approximately 68.
In this particular composition, the ratio of P.sup.1a to P.sup.2a to P.sup.2 is approximately 50:1:1.

Example 11

(46) This example demonstrates the use of the polymerization system of the present invention with a chain transfer agent Y-A-(Y).sub.n and a catalyst L.sub.p-M-(L.sub.I).sub.m utilizing a co-catalyst PPN+ Cl—, where n is 1, each —Y is —CO.sub.2H, -A- is

(47) ##STR00088## -L.sub.p is a salcy ligand

(48) ##STR00089## -M- is Co(III), and -L.sub.I is trifluoroacetate.

(49) An oven dried glass vessel was charged with 11.5 mg of catalyst E2 (0.016 mmol); 9.2 mg of PPN.sup.+Cl.sup.− (0.016 mmol); adipic acid (0.12 g, 0.8 mmol) and 0.5 mL THF. Propylene oxide (4.5 mL, 64 mmol) was then added. The reaction vessel was pressurized with 300 psig dry carbon dioxide gas and stirred at 30° C. for 3 hours. The reaction was quenched with acid, diluted with 25 mL acetone and concentrated to yield 3.0 g of crude polymer. The polymer had an Mn of 13,933 g/mol, and a PDI of 1.04. The polymer contained no detectable ether linkages and had greater than 98% —OH end groups.

(50) The polycarbonate polyol composition thus obtained consists predominantly of three types of polymer chains: chains Pia arising from initiation by the adipic acid, chains P.sup.2a arising from initiation by the trifluoroacetate (L.sub.I) and chains P.sup.2 arising from the chloride counterion on the PPN co-catalyst:

(51) ##STR00090##
where each p is on average approximately 68.

(52) In this particular composition, the ratio of P.sup.1a to P.sup.2a to P.sup.2 is approximately 50:1:1.

Example 12

(53) This example demonstrates the use of the polymerization system of the present invention with a chain transfer agent Y-A-(Y).sub.n and a catalyst L.sub.p-M-(L.sub.I).sub.m utilizing a co-catalyst PPN+ Cl—, where n is 1, each —Y is —CO.sub.2H, -A- is

(54) ##STR00091## -L.sub.p is a salcy ligand

(55) ##STR00092## -M- is Co(III), and -L.sub.I is trifluoroacetate.

(56) An oven dried glass vessel was charged with 11.5 mg of catalyst E2 (0.016 mmol); 9.2 mg of PPN.sup.+Cl.sup.− (0.016 mmol); terephthalic acid (0.13 g, 0.8 mmol) and 0.5 mL THF. Propylene oxide (4.5 mL, 64 mmol) was then added. The reaction vessel was pressurized with 300 psig dry carbon dioxide gas and stirred at 30° C. for 3 hours. The reaction was quenched with acid, diluted with 25 mL acetone and concentrated to yield 1.52 g of crude polymer. The polymer had an Mn of 13,621 g/mol, and a PDI of 1.35. The polymer contained no detectable ether linkages and had greater than 98% —OH end groups.

(57) The polycarbonate polyol composition thus obtained consists predominantly of three types of polymer chains: chains Pa arising from initiation by the terephthalic acid, chains P.sup.2a arising from initiation by the trifluoroacetate (L.sub.I) and chains P.sup.2 arising from the chloride counterion on the PPN co-catalyst:

(58) ##STR00093##
where each p is on average approximately 68. In this particular composition, the ratio of P.sup.1a to P.sup.2a to P.sup.2 is approximately 50:1:1.

Example 13

(59) This example demonstrates the use of the polymerization system of the present invention with a chain transfer agent Y-A-(Y).sub.n and a catalyst L.sub.p-M-(L.sub.I).sub.m utilizing a co-catalyst PPN+ Cl—, where n is 1, each —Y is —CO.sub.2H, -A- is

(60) ##STR00094## -L.sub.p is a salcy ligand

(61) ##STR00095## -M- is Co(III), and -L.sub.I is trifluoroacetate.

(62) An oven dried glass vessel was charged with 11.5 mg of catalyst E2 (0.016 mmol); 9.2 mg of PPN.sup.+Cl.sup.− (0.016 mmol); maleic acid (0.095 g, 0.8 mmol) and 0.5 mL THF. Propylene oxide (4.5 mL, 64 mmol) was then added. The reaction vessel was pressurized with 300 psig dry carbon dioxide gas and stirred at 30° C. for 3 hours. The reaction was quenched with acid, diluted with 25 mL acetone and concentrated to yield 3.3 g of crude polymer. The polymer had an Mn of 5919 g/mol, and a PDI of 1.03. The polymer contained no detectable ether linkages and had greater than 98% —OH end groups.

(63) The polycarbonate polyol composition thus obtained consists predominantly of three types of polymer chains: chains P.sup.1a arising from initiation by the succinic acid, chains P.sup.2a arising from initiation by the trifluoroacetate (L.sub.I) and chains P.sup.2 arising from the chloride counterion on the PPN co-catalyst:

(64) ##STR00096##
where each p is on average approximately 29. In this particular composition, the ratio of P.sup.1a to P.sup.2a to P.sup.2 is approximately 50:1:1.

Example 14

(65) This example demonstrates the use of the polymerization system of the present invention with a chain transfer agent Y-A-(Y).sub.n and a catalyst L.sub.p-M-(L.sub.I).sub.m utilizing a co-catalyst PPN+ Cl—, where n is 1, each —Y is —OH, -A- is

(66) ##STR00097## -L.sub.p is a salcy ligand

(67) ##STR00098## -M- is Co(III), and -L.sub.I is trifluoroacetate.

(68) An oven dried glass vessel was charged with 11.5 mg of catalyst E2 (0.016 mmol) and 9.2 mg of PPN.sup.+Cl.sup.− (0.016 mmol). The vessel was purged with nitrogen and isosorbide (0.12 g, 0.8 mmol) was added as a solution in dry THF (0.5 mL). Propylene oxide (4.5 mL, 64 mmol) was then added. The reaction vessel was pressurized with 300 psig dry carbon dioxide gas and stirred at 30° C. for 3 hours. The reaction was quenched with acid, diluted with 25 mL acetone and concentrated to yield 1.53 g of crude polymer. The polymer had an Mn of 2342 g/mol, and a PDI of 1.05. The polymer contained no detectable ether linkages and had greater than 98% —OH end groups.

(69) The polycarbonate polyol composition thus obtained consists predominantly of three types of polymer chains: chains P.sup.1a arising from initiation by the isosorbide, chains P.sup.2a arising from initiation by the trifluoroacetate (L.sub.I) and chains P.sup.2 arising from the chloride counterion on the PPN co-catalyst:

(70) ##STR00099##
where each p is on average approximately 11.

(71) In this particular composition, the ratio of to P.sup.1a to P.sup.2a to P.sup.2 is approximately 50:1:1.

Example 14

(72) This example demonstrates the use of the polymerization system of the present invention with a chain transfer agent Y-A-(Y).sub.n and a catalyst L.sub.p-M-(L.sub.I).sub.m utilizing a co-catalyst PPN+ Cl—, where n is 1, each —Y is —OH, -A- is

(73) ##STR00100## where n′ is 10-30 and the avg. MW is 600 g/mol; -L.sub.p is a salcy ligand

(74) ##STR00101## -M- is Co(III), and -L.sub.I is trifluoroacetate.

(75) An oven dried glass vessel was charged with 11.5 mg of catalyst E2 (0.016 mmol); 9.2 mg of PPN.sup.+ Cl.sup.− (0.016 mmol); paraformaldehyde (24 mg, 0.04 mmol); and dry THF (0.5 mL). Propylene oxide (4.5 mL, 64 mmol) was then added. The reaction vessel was pressurized with 300 psig dry carbon dioxide gas and stirred at 30° C. for 3 hours. The reaction was quenched with acid, diluted with 25 mL acetone and concentrated to yield 1.0 g of crude polymer. The polymer had an Mn of 13,262 g/mol, and a PDI of 1.18.

(76) The polycarbonate polyol composition thus obtained consists predominantly of three types of polymer chains: chains P.sup.aa arising from initiation by the isosorbide, chains P.sup.2a arising from initiation by the trifluoroacetate (L.sub.I) and chains P.sup.2 arising from the chloride counterion on the PPN co-catalyst:

(77) ##STR00102##
where n′ is 10-30 and each p is on average approximately 60.

(78) In this particular composition, the ratio of p.sup.1a to P.sup.2a to P.sup.2 is approximately 2:1:1.

Example 15

(79) This example demonstrates the use of the polymerization system of the present invention with a chain transfer agent Y-A-(Y).sub.n and a catalyst L.sub.p-M-(L.sub.I).sub.m, where, n is 1, each —Y is —OH, -A- is

(80) ##STR00103##
(mixture of isomers); -L.sub.p is

(81) ##STR00104##
where each X is trifluoroacetate. -M- is Co(III), and -L.sub.I is trifluoroacetate.

(82) In a glovebox, catalyst (5.4 mg, 1.0 equiv) was charged to an oven-dried 20 mL glass liner. The liner was inserted into a stainless steel high pressure reactor. The system was purged with N.sub.2 five times and purged with CO.sub.2 twice. While under the positive flow of CO.sub.2, a solution of dipropylene glycol (75 μL) in propylene oxide (5 mL, 25,000 equiv) was charged to the reaction vessel. The reaction was heated to 50° C., then pressurized with carbon dioxide (300 psi) and stirred.

(83) After 6 h the reaction was vented and quenched with acidic methanol (0.2 mL). The reaction was cooled to room temperature, and the resulting polymer was diluted with acetone (5 mL) and transferred to a foil pan. The unreacted propylene oxide and acetone were removed by evaporation to produce 2.19 g of an off-white polymer (M.sub.w=5,600, M.sub.w/M.sub.n=1.03.

(84) The polycarbonate polyol composition thus obtained consists predominantly of two types of polymer chains: chains P.sup.1 arising from initiation by the dipropylene glycol, and chains P.sup.2 arising from initiation by the trifluoroacetate (from L.sub.I and X).

(85) ##STR00105##

(86) where each p is on average approximately 27.

(87) In this particular composition, the ratio of P.sup.1 to P.sup.2 is approximately 4:1.

Other Embodiments

(88) The foregoing has been a description of certain non-limiting embodiments of the invention. Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.