CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Patent Application No. 60/839,682, filed Aug. 24, 2006, the whole of which is incorporated herein by reference.

This invention was made at least in part with U.S. Government support under NSF grant numbers CHE-0243605 and DMR-0079992. The Government has certain rights in the invention.

TECHNICAL FIELD

This invention is directed to homopolymerization of propylene oxide and copolymerization of propylene oxide and carbon dioxide, using double metal cyanide catalysts.

BACKGROUND OF THE INVENTION

Zinc hexacyanometalates have been used for epoxide/carbon dioxide copolymerization. A drawback to these catalysts is that undesired by-product propylene carbonate (requiring purification) is also formed unless such low temperatures are utilized that catalyst activity is significantly reduced.

SUMMARY OF THE INVENTION

It has been discovered herein that tetracyanometallate containing double metal cyanide complexes readily catalyzed the copolymerization of propylene oxide and carbon dioxide without the formation of propylene carbonate. These complexes are also functional to catalyze the homopolymerization of propylene oxide.

In one embodiment of the invention herein, denoted the first embodiment, the invention is directed to a method for the non-alternating copolymerization of rac-propylene oxide or enantomerically enriched propylene oxide and carbon dioxide to produce

[Image Omitted]

where x ranges from 1.0 to 0.46 and M_nranges from 500 to 500,000 g/mol, e.g. 10,000 to 500,000 g/mol. This method comprises the step of copolymerizing rac-propylene oxide or enantomerically enriched propylene oxide and carbon dioxide in the presence of a catalytically effective amount of a double metal cyanide complex containing a tetracyanometallate moiety, e.g., anhydrous Co[M(CN)₄] where M is selected from the group consisting of Ni, Pd and Pt and combinations thereof, or hydrated or partially dehydrated form thereof.

In another embodiment of the invention herein, denoted the second embodiment, the invention is directed to a method for the homopolymerization of rac-propylene oxide or enantomerically enriched propylene oxide, comprising the step of polymerizing rac-propylene oxide or enantomerically enriched propylene oxide in the presence of a catalytically effective amount of a double metal cyanide complex containing a tetracyanometallate moiety, e.g., anhydrous Co[M(CN)₄] where M is selected from the group consisting of Ni, Pd and Pt and combinations thereof, to produce poly(propylene oxide) having M_nranging from 500 to 250,000 g/mol.

In another embodiment of the invention, denoted the third embodiment, the invention is directed to a method of preparing Co[M(CN)₄] comprising reacting cobalt salt, preferably Co(SO₄), and K₂[M(CN)₄] to form hydrated Co[M(CN)₄] and dehydrating the hydrated Co[M(CN)₄] to produce anhydrous Co[M(CN)₄] where M is selected from the group consisting of Ni, Pt and Pd.

In another embodiment herein, denoted the fourth embodiment, the invention is directed to the method of preparing anhydrous Co[M(CN)₄], where M is selected from the group consisting of Ni, Pt, and Pd, comprising the step of dehydrating microcrystalline Co(H₂O)₂[M(CN)₄].4H₂O. As used herein the term microcrystalline means having crystal dimensions less than 1.0 mm in the narrowest dimension.

In another embodiment herein, denoted the fifth embodiment, the invention is directed at Co[Pt(CN)₄].

In still another embodiment herein, denoted the sixth embodiment, the invention is directed at Co[Pd(CN)₄].

In still another embodiment, denoted the seventh embodiment, the invention is directed to a method for non-alternating copolymerization of

[Image Omitted]

where R in (I) is selected from the group consisting of hydrogen, C₂-C₁₈-alkyl, C₆-C₁₈-aryl, C₁-C₂₀halide (e.g., F, I, Cl, Br) containing alkyl, and C₁-C₂₀oxygen-containing alkyl, and

carbon dioxide (II),

comprising the step of copolymerizing (I) and (II) in the presence of a catalytically effective amount of double metal cyanide complex containing a tetracyanometallate moiety, to produce polyether-polycarbonate having the formula

[Image Omitted]

where x ranges from 1.0 to 0.46 and M_nof (III) ranges from 500 to 500,000 g/mol, e.g., 10,000 to 500,000 g/mol.

In another embodiment herein, denoted the eighth embodiment, the invention is directed to a method for homopolymerization of

[Image Omitted]

where R in (I) is selected from the group consisting of hydrogen, C₂-C₁₈-alkyl, C₆-C₁₈-aryl, C₁-C₂₀halide (e.g., F, I, Cl, Br) containing alkyl, and C₁-C₂₀oxygen-containing alkyl, comprising the step of polymerizing (I) in the presence of a double metal cyanide complex containing a tetracyanometallate moiety to produce poly(substituted ethylene oxide (I)) having the formula

[Image Omitted]

where R is as defined above, and M_nranges from 500 to 250,000 g/mol.

The term â€œtetracyanometallate moietyâ€ is used herein to refer to metal surrounded by and bound to four cyanides where the metal is bound to the carbon atoms of the cyanide ligands.

The term â€œenantomerically enriched propylene oxide is used herein to mean propylene oxide where the ratio of enantiomers is not 50:50.

Alternating polymerization provides A-B-A-B-A-B-A-B, etc. where A represents propylene oxide unit (PO unit) and B a CO₂unit, i.e., there are no adjacent propylene oxide units. In non-alternating polymerization, the product contains adjacent propylene oxide units.

In many cases there are more PC units than PO units. PO/CO₂copolymers, with approximately 15% carbonate units are considered to be soluble in supercritical CO₂apparently because of surfactant functionality. (Sarbu, J., et al., Nature 405, 165-168 (2000)).

As used herein M_n, M_wand M_w/M_n(PDI) are determined by gel permeation chromatography calibrated with polystyrene standards in tetrahydrofuran at 40Â° C.

DETAILED DESCRIPTION

Elements of the invention and working examples are found in Robertson, N. J., et al., Dalton Trans., 2006, 5390-5395 and Electronic Supplementary Information, pages S1-S10, the whole of both of which are incorporated herein by reference.

We turn firstly to the catalyst.

The catalyst for the first embodiment has the formula Co[M(CN)₄] where M is selected from the group consisting of Ni, Pt and Pd and combinations thereof. For the first embodiment the catalyst can be in hydrated form, e.g., Co(H₂O)₂[M(CN)₄].4H₂O, partially dehydrated form, e.g., Co(H₂O)₂[M(CN)₄], or anhydrous form, i.e., Co[M(CN)₄].

The catalyst for the second embodiment has the formula Co[M(CN)₄] where M is selected from the group consisting of Ni, Pd and Pt and combinations thereof, in the anhydrous form, i.e., homopolymerization was obtained with the anhydrous form but not with the hydrated or partially dehydrated forms.

The catalysts are prepared by forming hydrated form using a modified procedure of that described in Niu, T., Crisci, G., Lu, T. and Jacobson, A. J., Acta Cryst., Sect. C, 54, 565-567 (1998), the whole of which is incorporated herein by reference. An aqueous solution of K₂[M(CN)₄] is reacted with aqueous solution of Co^II-based salt to produce Co(H₂O)₂[M(CN)₄].4H₂O. The use of Co(SO₄) was used in place of the Co(SCN)₂used by Jacobson. It was found that the use of Co(SO₄) in this synthesis yields the Co[M(CN)₄] complexes with higher activities in the as made form, i.e., without extensive washing, that is higher than when the complexes were made utilizing other cobalt sources. For example, when Co(SCN)₂is used, extensive washing is required to obtain the same activity as when Co(SO₄) is used without extensive washing, and when CoCl₂is used, extensive washing is required to prevent chloride poisoning of the active catalyst. Vacuum filtering of reaction product yields hydrated catalyst. Drying in vacuo for a protractice time, e.g., overnight, gives anhydrous catalyst. Drying in vacuo for a short time, e.g., 1 hour, gives partially dehydrated catalyst.

The starting materials K₂[Ni(CN)₄], K₂[Pt(CN)₄] and K₂[Pd(CN)₄] are all commercially available.

Working Example I, hereinafter, is directed to preparation of Co(H₂O)₂[Ni(CN)₄].4H₂O and Co[Ni(CN)₄]. Working Example II, hereinafter, is directed to synthesis of Co[Pt(CN)₄] and Co[Pd(CN)₄].

We turn now to reaction conditions for the first embodiment besides the description of the catalyst.

The mole ratio of propylene oxide charged to catalyst charged PO:Co mole ratio basis, can range, for example, from 100:1 to 100,000:1, e.g., 100:1 to 5000:1, e.g., 500:1 to 2000:1.

The carbon dioxide pressure can range, for example, from ambient pressure (e.g., 1 atmosphere) to 1500 psig. When the carbon dioxide pressure is greater than 1 atmosphere, e.g., is 800 psig, the pressure defines the amount of carbon dioxide. When the carbon dioxide pressure is ambient, the amount of carbon dioxide is provided by the headspace in the reactor, e.g., 200 to 1000 ml. When the pressure is increased, the amount of carbonate units increases but catalyst activity decreases,

The copolymerization can be carried out neat (without other solvent, i.e., the liquid propylene oxide acts as the reaction medium) or in hydrocarbon solvent, e.g., toluene or xylene.

In runs carried out, copolymerizations were carried out neat and in toluene.

The temperature at which the copolymerization is carried out, can range, for example from 10Â° C. to 150Â° C., e.g., 25 to 135Â° C. Catalyst activity increases with increasing temperature. Longer reaction time can accommodate for lower temperature.

Reaction times range, for example, from 15 minutes to 5 days, e.g. 30 minutes to 30 hours. A representative copolymerization procedure is as follows: A 100 mL Parr autoclave equipped with a mechanical stirrer is dried under vacuum at 80Â° C. for 2 h and then transferred to a drybox to cool to 22Â° C. Co[Ni(CN)₄] (10.0 mg, 0.0450 mmol) is put into a glass sleeve in the autoclave. Toluene (8.0 mL) and PO (8.0 mL, 0.11 mol) were added under nitrogen via an injection port. The autoclave is pressurized to 34.0 atm and then heated to 90Â° C. over 20 min. During this time the pressure increases to the desired 54.4 atm. If the CO₂pressure is lower than desired once heating is complete, additional CO₂is added to reach the desired pressure. The total reaction time from initial pressurizing is 1 h. The autoclave is cooled and vented to yield a large polymer mass, which was dissolved in CHCl₃to ensure the same was homogeneous before taking an aliquot for ¹H NMR analysis. The solvent is removed by rotary evaporation and the resulting polymer is dried in vacuo at 50Â° C. to a constant weight to determine polymer yield (4.77 g, 60%). The resulting polymer is dissolved in toluene and treated with 10% aqueous NH₄OH(20 mL) to remove the catalyst and then dried in vacua to a constant mass.

Working examples of copolymerization are given in Working Examples III-XVI hereinafter.

In all cases the copolymers formed are regioregular and atactic as determined by ¹³C{¹H}NMR spectroscopy and are amorphous.

M_ncan range, for example, from 500 to 500,000 g/mol, e.g., 10,000 to 500,000 g/mol or 15,000 to 250,000 g/mol, with M_w/M_n(PDI) ranging, for example, from 1.9 to 5.8, usually about 2.0 to 4.0. The M_ncan be reduced by an order of magnitude, e.g., to 500 to 25,000 or 5,000 g/mole, by addition of chain transfer agent (CTA), e.g., alcohol, e.g., methanol, glycerol or polyhydroxy compound such as PG425 polyol (which is polypropylene glycol of molecular weight of 425 g/mol, or carboxylic acid, e.g., acetic acid., into the reaction mixture, e.g., in an amount of 1 to 500 equivalents of CTA versus Co(Ni(CN)₄]. No propylene carbonate formation was observed in ¹H NMR spectroscopic analysis in any of the runs carried out.

We turn now to the second embodiment.

The catalyst and its preparation is described above.

The mole ratio of propylene oxide charged to catalyst charged, can range, for example, from 100:1 to 5000:1. Working examples were carried out at 2530:1 PO:Co mole ratio.

The polymerization is readily carried out at ambient pressure.

The reaction can be carried out neat (i.e., without other solvent and the liquid propylene oxide acts as the reaction medium) or in the solvents described for the first embodiment.

Temperatures at which homopolymerization can be carried out range, for example, from 10Â° C. to 150Â° C., e.g. 50-100Â° C.

Times at which the homopolymerization is carried out, ranges, for example, from 15 minutes to 5 days, e.g. 30 minutes to 24 hours.

Working Example XVII is directed to the homopolymerization reaction.

The homopolymers formed have M_nranging from 500 to 500,000 g/mol, e.g., 10,000 to 500,000 g/mol or e.g., about 40,000 to 200,000 g/mol, with PDI ranging from 1.5 to 5, e.g., 1.9 to 2.5. The M_ncan be reduced by an order of magnitude, e.g., to 500 to 25,000 or 5,000 g/mole, by addition of chain transfer agent, e.g., those mentioned as CTAs above, into the reaction mixture, e.g., in an amount of 1 to 500 equivalents of CTA versus Co(Ni(CN)₄].

The homopolymers formed are regioregular and atactic and are amorphous.

The copolymers and homopolymers made herein are useful for polyurethane synthesis and the polyurethanes are useful as materials for forming foam cushions.

We turn now to the third embodiment.

As indicated above, the use of Co(SO₄) as the cobalt salt results in as made catalyst with much higher activity than when other cobalt salts, e.g., CoCl₂or Co(SCN)₂are used. Catalysts made with other salts require extensive washing, e.g., multiple washings of the complex on filter paper with water, for the same activity. The higher activity is manifested by amount of polymer formed per amount of catalyst being higher in a given amount of time.

We turn now to the fourth embodiment.

Microcrystalline hydrated catalyst is better as a starting compound for dehydration because it has a higher surface area than larger crystalline hydrated catalyst.

We turn now to the fifth embodiment.

Co[Pt(CN)₄] can be prepared as described above starting with K₂[Pt(CN)₄] which is commercially available.

We turn now to the sixth embodiment.

Co[Pd(CN)₄] can be prepared as described above starting with K₂[Pd(CN)₄] which is commercially available. It catalyzes more CO₂incorporation than does Co[Ni(CN)₄] at the same conditions.

We turn now to the seventh embodiment. A species of this is the method of the first embodiment.

We turn now to the eighth embodiment. A species of this is the method of the second embodiment.

The complex used as catalyst for the seventh and eighth embodiments is preferably Co[M(CN)₄], e.g., where M is Ni.

The invention is illustrated by the following working examples.

WORKING EXAMPLE IPreparation of Co[Ni(CN)₄]

The complex Co(H₂O)₂[Ni(CN)₄].4H₂O was prepared using a modified procedure of Niu et al., cited above, substituting CoSO₄for Co(SCN)₂. With vigorous stirring, 10 mL of a 0.23 M aqueous K₂[Ni(CN)₄] solution and 10 mL of a 0.23 M aqueous CoSO₄solution were mixed. A pink precipitate instantly formed, and an additional 10 mL of distilled water were added to reduce the viscosity of the suspension. The mixture was stirred vigorously for 1 h and then vacuum filtered to yield a pink microcrystalline material. The powder X-ray data of this complex matched the calculated data for Co(H₂O)₂Ni(CN)₄.4H₂O. The complex was dried in vacuo at 60Â° C. for 10 h yielding the deep purple solid Co[Ni(CN)₄] (0.42 g, 83%) that was subsequently ground into a powder with a mortar and pestle and then used in polymerizations. Thermogravimetric and elemental analyses revealed that >97% of the inter-layer water molecules were removed.

WORKING EXAMPLE IIPreparation of Co[M(CN)₄] Where M=Pd Or Pt

The analogous complexes Co[Pd(CN)₄] and Co[Pt(CN)₄] were prepared using the same procedure as used in Working Example I for Co[Ni(CN)₄]. In each case, with vigorous stirring 10 mL of a 0.23 M aqueous K₂[M(CN₄)] solution and 10 mL of a 0.23 M aqueous CoSO₄solution were mixed and a pink precipitate instantly formed. In each case an additional 10 mL of distilled water was added, followed by vigorous stirring for 1 hour and vacuum filtering to recover product. Isolated yields were 89 and 84%, respectively. Thin pink-orange plates of Co(H₂O)₂[Pd(CN)₄].4H₂O for X-ray analysis were obtained by layering a solution of CoCl₂.6H₂O in ethanol onto a solution of K₂[Pd(CN)₄].3H₂O in water and storing in a sealed test-tube at 22Â° C. for a period of two weeks.

WORKING EXAMPLE IIICopolymerization Using Co[Ni(CN₄)]

The representative copolymerization procedure described above was varied as necessary to provide the conditions following. The catalyst was anhydrous Co[Ni(CN)₄]. Copolymerization was carried out for 1 hr with 16 mL of 7.1 M rac-PO in toluene, [PO]/[Co]=2530. Initial CO₂pressure was 34 atm. The autoclave was heated to 130Â° C. The CO₂pressure increased to 54.4 atm. Copolymer yield on drying in vacuo at 50Â° C. for 8 hours was 5.57 g. The carbonate fraction determined by ¹H NMR spectroscopy (CDCl₃, 300 MHz) referenced versus non-deuterated solvent shifts (¹H, CHCl₃, Î´ 7.25) f_co2was 0.20. The propylene oxide conversion (equal to polymer mass/(0.114 mol PO)[102Ã—_fco2+(58Ã—(1âˆ’_fco2)] was 73%. The turnover frequency, i.e. TOF, was 1860 where TOF equals (mole PO)Â·(mole Co)^âˆ’1Â·h^âˆ’1. M_nwas 74,300 g/mol. M_w/M_nwas 3.1. No propylene carbonate was observed.

WORKING EXAMPLE IVCopolymerization Using Co[Ni(CN₄)]

The procedure used in Working Example III was followed except the temperature of reaction was 110Â° C. Copolymer yield was 5.39 g. The f_co2was 0.22. The conversion of PO was 70%. TOF was 1770. M_nwas 84,100 g/mol. M_w/M_nwas 2.9. No propylene carbonate was observed.

WORKING EXAMPLE VCopolymerization Using Co[Ni(CN)₄)]

The procedure used in Working Example III was followed except that the temperature of reaction was 90Â° C. Copolymer yield was 4.77 g. The f_co2was 0.27. The conversion of PO was 60%. TOF was 1510. M_nwas 86,000 g/mol. M_w/M_nwas 2.8. No propylene carbonate was observed.

In another case reaction was carried out as above except that the reaction was run in 8.0 mL neat rac-PO and the reaction time was 2 hours. Copolymer yield was 2.95 g. The f_co2was 0.25. The conversion of PO was 37%. TOF was 470. M_nwas 3,000 g/mol. M_w/M_nwas 7.1. No propylene carbonate was observed.

WORKING EXAMPLE VICopolymerization Using Co[Ni(CN)4]

The procedure used in Working Example III was followed except the temperature of reaction was 70Â° C. Copolymer yield was 3.79 g. The f_co2was 0.3. The conversion of PO was 46%. TOF was 1170. M_nwas 152,000 g/mol. M_w/M_nwas 3.7. No propylene carbonate was observed.

WORKING EXAMPLE VIICopolymerization Using Co[Ni(CN)₄]

The procedure used in Working Example III was followed except the temperature of reaction was 50Â° C. Copolymer yield was 1.29 g. The f_co2was 0.36. The conversion of PO was 15%. TOF was 390. M_nwas 163,000 g/mol. M_w/M_nwas 5.8. No propylene carbonate was observed.

WORKING EXAMPLE VIIICopolymerization Using Co[Ni(CN)₄]

The procedure used in Working Example III was followed except the temperature of reaction was 30Â° C. and the reaction time was 5 days. Copolymer yield was 7.19 g. The f_co2was 0.56. The propylene oxide conversion was 76%. TOF was 16. M_nwas 148,000 g/mol. M_w/M_nwas 5.1. No propylene carbonate was observed.

WORKING EXAMPLE IXCopolymerization Using Co[Ni(CN)₄]

The procedure used in Working Example III was followed except the temperature of reaction was 70Â° C. and the CO₂pressure after heating was 81.6 atm. Copolymer yield was 1.81 g. The f_co2was 0.38. The propylene oxide conversion was 21%. TOF was 540. M_nwas 152,000 g/mol. M_w/M_nwas 4.3. No propylene carbonate was observed.

WORKING EXAMPLE XCopolymerization Using Co[Ni(CN)₄]

The procedure used in Working Example III was followed except the temperature of reaction was 70Â° C. and the CO₂pressure after heating was 68.0 atm. Copolymer yield was 2.57 g. The f_co2was 0.35. The propylene oxide conversion was 31%. TOF was 780. M_nwas 233,000 g/mol. M_w/M_nwas 4.8. No propylene carbonate was observed.

WORKING EXAMPLE XICopolymerization Using Co[Ni(CN)₄]

The procedure used in Working Example III was followed except the temperature of reaction was 70Â° C. and the CO₂pressure after heating was 40.8 atm. Copolymer yield was 3.92 g. The f_co2was 0.27. The propylene oxide conversion was 44%. TOF was 1250. M_nwas 116,000 g/mol. M_w/M_nwas 3.5. No propylene carbonate was observed.

WORKING EXAMPLE XIICopolymerization Using Co[Ni(CN)₄]

The procedure used in Working Example III was followed except the temperature of reaction was 70Â° C. and the CO₂pressure after heating was 27.2 atm. The copolymer yield was 3.74 g. The f_co2was 0.23. The propylene oxide conversion was 48%. TOF was 1220. M_nwas 111,000 g/mol. M_w/M_nwas 2.6. No propylene carbonate was observed.

WORKING EXAMPLE XIIICopolymerization Using Co[Ni(CN)₄]

The procedure used in Working Example III was followed except the temperature of reaction was 70Â° C. and the CO₂pressure after heating was 13.6 atm. The copolymer yield was 3.82 g. The f_co2was 0.16. The propylene oxide conversion was 51%. TOF was 1300. M_nwas 222,000 g/mol. M_w/M_nwas 3.8. No propylene carbonate was observed.

WORKING EXAMPLE XIVCopolymerization Using Co[Pd(CN)₄]

The procedure used in Working Example III was followed except the catalyst was anhydrous Co[Pd(CN)₄], the reaction temperature was 90Â° C. and the reaction time was 24 hours. The CO₂pressure after heating was 54.4 atm. The copolymer yield was 1.47 g. The f_co2was 0.43. The propylene oxide conversion was 17%. TOF was 18. M_nwas 25,600 g/mol. M_w/M_nwas 3.6. No propylene carbonate was observed.

WORKING EXAMPLE XVCopolymerization Using Co[Pt(CN)₄]

The procedure used in Working Example III was followed except the catalyst was anhydrous Co[Pt(CN)₄], the reaction temperature was 90Â° C. and the reaction time was 24 hours. The CO₂pressure after heating was 54.4 atm. The copolymer yield was 1.11 g. The f_co2was 0.44. The propylene oxide conversion was 13%. TOF was 13. M_nwas 27,900 g/mol. M_w/M_nwas 3.7. No propylene carbonate was observed.

WORKING EXAMPLE XVICopolymerizations Using Co[Ni(CN)4} Made Using Various Cobalt Salts

Complexes were prepared as in Working Example I except that Co(NO₃)₂, Co(BF₄)₂, CoCl₂, and (CoSCN)₂were used in place of CoSO₄. The prepared complexes were screened using the conditions of Working Example VI. Polymer masses obtained were 0.126 g of copolymer for Co(NO₃)₂, 0.765g of copolymer for Co(BF₄), 0.563 g of copolymer for CoCl₂and 0.305 g of copolymer for Co(SCN)₂. Based on these screens, the method to prepare Co[Ni(CN)₄] with highest activity was for catalyst prepared using CoSO₄.

WORKING EXAMPLE XVIIHomopolymerization Using Co[Ni(CN)₄]

The procedure used in Working Example III was followed except no CO₂was introduced and the temperature of reaction was 70Â° C. The CO₂pressure after heating was 0 atm. The polymer yield was 5.19 g. The f_co2was zero. The propylene oxide conversion was 78%. TOF was 1990. M_nwas 188,000 g/mol. M_w/M_nwas 3.6.

WORKING EXAMPLE XVIIIHomopolymerization Using Co[Ni(CN)₄]

A 100 mL Parr autoclave equipped with a mechanical stirrer is dried under vacuum at 80Â° C. for 2 h and then transferred to a drybox to cool to 22Â° C. Co[Ni(CN)₄] (10 mg, 0.045 mmol) is put into a glass sleeve in the autoclave. Toluene (8 mL) and PO (8 mL, 0.1 mol) is added under nitrogen via an injection port. The autoclave is then heated to 90Â° C. over 20 min. The total reaction time after initial heating is 1 h. The autoclave is cooled and vented to yield a large polymer mass, which is dissolved in CHCl₃to ensure the same is homogeneous before taking an aliquot for ¹H NMR analysis. The solvent is removed by rotary evaporation and the resulting polymer is dried in vacuo at 50Â° C. to a constant weight to determine polymer yield (6.0 g, 91%). The resulting polymer is dissolved in toluene and treated with 10% aqueous NH₄OH (20 mL) to remove the catalyst and then dried in vacuo to a constant mass. M_nis greater than 80,000 g/mol. M_w/M_nis greater than 2.

WORKING EXAMPLE XIXCopolymerization of Epichlorohydrin And Carbon Dioxide

A 100 mL Parr autoclave equipped with a mechanical stirrer is dried under vacuum at 80Â° C. for 2 h and then transferred to a drybox to cool to 22Â° C. Co[Ni(CN)₄] (10 mg, 0.045 mmol) is put into a glass sleeve in the autoclave. Toluene (8 mL) and epichlorohydrin (R in (I) is â€”CH₂Cl) (8 mL, 0.10 mol) is added under nitrogen via an injection port. The autoclave is pressurized to 34.0 atm and then heated to 90Â° C. over 20 min. During this time the pressure increases to the desired 54.4 atm. The total reaction time after initial pressurizing is 24 h. The autoclave is cooled and vented to yield a polymer mass, which is dissolved in CHCl₃to ensure the same was homogeneous before taking an aliquot for ¹H NMR analysis. The solvent is removed by rotary evaporation and the resulting polymer is dried in vacuo at 50Â° C. to a constant weight to determine polymer yield (1.1 g, 10%). The resulting polymer is dissolved in toluene and treated with 10% aqueous NH₄OH (20 mL) to remove the catalyst and then dried in vacuo to a constant mass. M_nis greater than 800 g/mol. M_w/M_nis greater than 2.

WORKING EXAMPLE XXHomopolymerization of Epichlorohydrin

A 100 mL Parr autoclave equipped with a mechanical stirrer is dried under vacuum at 80Â° C. for 2 h and then transferred to a drybox to cool to 22Â° C. Co[Ni(CN)₄] (10 mg, 0.045 mmol) is put into a glass sleeve in the autoclave. Toluene (8 mL) and epichlorohydrin (R in (I) is â€”CH₂C1) (8 mL, 0.10 mol) is added under nitrogen via an injection port. The autoclave is then heated to 90Â° C. over 20 min. The total reaction time after initial heating is 24 h. The autoclave is cooled and vented to yield a polymer mass, which is dissolved in CHCl₃to ensure the same was homogeneous before taking an aliquot for ¹H NMR analysis. The solvent is removed by rotary evaporation and the resulting polymer is dried in vacuo at 50Â° C. to a constant weight to determine polymer yield (1.8 g, 19%). The resulting polymer is dissolved in toluene and treated with 10% aqueous NH₄OH (20 mL) to remove the catalyst and then dried in vacuo to a constant mass. M_nis greater than 800 g/mol. M_w/M_nis greater than 2.

Variations

The foregoing description of the invention has been presented describing certain operable and preferred embodiments. It is not intended that the invention should be so limited since variations and modifications thereof will be obvious to those skilled in the art, all of which are within the spirit and scope of the invention.