MIXED-ACID MODIFIED ZINC-COBALT DOUBLE METAL CYANIDE CATALYST AND PREPARATION METHOD THEREOF
20210213431 ยท 2021-07-15
Inventors
Cpc classification
C08G65/2696
CHEMISTRY; METALLURGY
International classification
B01J35/00
PERFORMING OPERATIONS; TRANSPORTING
Abstract
The disclosure provides a double metal cyanide catalyst, a preparation method and a application method thereof. Besides impurities, there are only two metal elements consisted of zinc and cobalt in the catalyst. The catalyst is obtained by reacting water-soluble metal salts of zinc and cobalt in water-soluble solvents. The catalyst is modified by a mixed acid during synthesis of the catalyst, the mixed acid comprising at least one organic acid and at least one water-soluble inorganic acid. the water-soluble inorganic acid is selected from the group consisting of diluted sulfuric acid and diluted hydrochloric acid, with a pH value being in the range of 0 to 5; and the organic acid is any one or more selected from the group consisting of succinic acid, glutaric acid, phthalic acid, iminodiacetic acid, pyromellitic acid, and 1,2,3,4-butanetetracarboxylic acid.
Claims
1. A mixed-acid modified zinc-cobalt double metal cyanide catalyst, comprising only the two metal elements of zinc and cobalt, besides impurities; the catalyst is obtained by reacting water-soluble metal salts of zinc and cobalt in water-soluble solvent, and the water-soluble metal salt of cobalt is cobalt cyanide salt; the catalyst is modified by mixed acid during synthesis of the catalyst, the mixed acid comprising at least one organic acid and at least one water-soluble inorganic acid, wherein: the water-soluble inorganic acid is selected from the group consisting of diluted sulfuric acid and diluted hydrochloric acid, with a pH value being in the range of 0 to 5; the organic acid is one or more selected from the group consisting of succinic acid, glutaric acid, phthalic acid, iminodiacetic acid, pyromellitic acid, and 1,2,3,4-butanetetracarboxylic acid; the water-soluble inorganic acid and organic acid being in a molar ratio of 1:10 to 10:1.
2. The catalyst according to claim 1, wherein the water-soluble inorganic acid is selected from the group consisting of diluted sulfuric acid and diluted hydrochloric acid, with a pH value being in the range of 0 to 4.
3. The catalyst according to claim 1, wherein the molar ratio of zinc and cobalt in the catalyst is 1:5 to 5:1.
4. The catalyst according to claim 1, wherein the water-soluble inorganic acid and organic acid is in a molar ratio of 1:8 to 8:1.
5. The catalyst according to claim 1, wherein a microscopic morphology of the catalyst is irregular polyhedral particles, and the particle size is in the range of 1 to 100 nm.
6. The catalyst according to claim 1, wherein the amorphous non-crystalline ratio of the catalyst is greater than 90%.
7. A method of preparing a catalyst, comprising the following steps: i) reacting at least one water-soluble zinc salt and at least one water-soluble cobalt salt in an aqueous solvent in the presence of the mixed acid; wherein the water-soluble cobalt salt is a cobalt cyanide salt; the mixed acid comprises at least one organic acid and at least one water-soluble inorganic acid, wherein: the water-soluble inorganic acid is selected from the group consisting of diluted sulfuric acid and diluted hydrochloric acid, with pH value being in the range of 0 to 5; the organic acid is one or more selected from the group consisting of succinic acid, glutaric acid, phthalic acid, iminodiacetic acid, pyromellitic acid, 1,2,3,4-butanetetracarboxylic acid; the water-soluble inorganic acid and organic acid is in a molar ratio of 1:10 to 10:1; ii) obtaining the mixed acid modified ZnCo double metal cyanide catalyst by separating, washing and drying the catalyst obtained in step i) for several times until the pH of the detergent in the range of 6 to 7.
8. The method according to claim 7, wherein the water-soluble inorganic acid is selected from the group consisting of diluted sulfuric acid and diluted hydrochloric acid, with a pH value being in the range of 0 to 4.
9. The method according to claim 7, wherein the water-soluble zinc salt in step i) is one or more selected from the group consisting of zinc chloride, zinc bromide, zinc iodide, zinc sulfate and zinc acetate.
10. The method according to claim 7, wherein the water-soluble cobalt salt in step i) is selected from the group consisting of sodium hexacyanocobaltate (III) and potassium hexacyanocobaltate (III).
11. The method according to claim 7, wherein the steps i) and ii) are carried out at one or more temperatures ranging from 10 C. to 100 C.
12. The method according to claim 7, wherein the water-soluble zinc salt and water-soluble cobalt salt in step i) is in a molar ratio of 1:5 to 5:1.
13. The method according to claim 7, wherein a ratio between the total mass of water-soluble zinc salt and water-soluble cobalt salt and the mass of water-based solvent is 1:1 to 1:200.
14. The method according to claim 7, wherein a ratio between the total moles of the water-soluble zinc salt and the water-soluble cobalt salt and the total moles of mixed acid is 1:10 to 10:1.
15. The method according to claim 7, wherein the water-soluble inorganic acid and the organic acid is in a molar ratio of 1:8 to 8:1.
16. The method according to claim 7, wherein the aqueous solvent is one or more selected from the group consisting of water, methanol, ethanol, propanol and its isomers, butanol and its isomers, amyl alcohol and its isomers, hexanol and its isomers, heptanol and its isomers.
17. A method of administering the catalysts of claim 1 in a chemical reaction.
18. The method according to claim 17, wherein the chemical reaction is a polymerization reaction and the polymerization reaction is the copolymerization of an epoxide with carbon dioxide.
19. The method according to claim 18, wherein the polymerization reaction is carried out in a continuous reactor, with the reaction pressure in the range of 1 to 20 MPa and the reaction temperature in the range of 50 to 150 C.
20. The method according to claim 19, wherein the reaction pressure in the range of 2 to 15 MPa and the reaction temperature in the range of 60 to 120 C.
21. The method according to claim 18, wherein the polymerization reaction further comprises a premixing step of the reaction raw material, with the pressure of the premixing step in the range of 0.1 to 2 MPa and the temperature in the range of 10 to 60 C.
22. The method according to claim 21, wherein the time of the premixed step is in the range of 1 to 6 hours.
23. The method according to claim 19, wherein an average residence time in the range of 0.5 to 10 hours in a continuous reactor.
24. The method according to claim 19, wherein the continuous reactor is a tubular reactor.
25. The method according to claim 24, wherein the tubular reactor is composed of continuous tube segments.
26. The method according to claim 24, wherein the inner diameter of the tubular reactor is 10 mm to 500 mm.
27. The method according to claim 24, wherein the ratio of the tube length L to the tube diameter dR of the tubular reactor is L/dR>50.
28. The method according to claim 17, wherein the epoxides are one or more selected from the group consisting of ethylene oxide, propylene oxide, 1,2-epoxy-butane, 2,3-epoxy-butane, styrene oxide, cyclohexene oxide, and epichlorohydrin.
29. The method according to claim 17, wherein the reaction material of the polymerization reaction further comprises an initiator.
30. The method according to claim 29, wherein the added initiator and epoxide is in a molar ratio of 1:20 to 1:200.
31. The method according to claim 29, wherein the initiator is one or more selected from the group consisting of ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-butyl glycol, 1,6-adipic alcohol, 1,4-cyclohexanedimethanol, neopentyl glycol, glycerin, trimethylolpropane, trihydroxymethyl ethane, 1,2,4-trichlorobenzene butyl alcohol, 1,2,6-butyloyl glycol, pentaerythritol, dipentaerythritol, succinic acid, glutaric acid, adipic acid, pimelic acid, octyl diacid, azelaic acid, sebacic acid, lauric acid, terephthalic acid, isophthalic acid, phthalic acid, trimesic acid, benzene tetracarboxylic acid, catechol, resorcinol and hydroquinone.
Description
BRIEF DESCRIPTION OF DRAWINGS
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DETAILED DESCRIPTION OF THE DISCLOSURE
[0078] The above scheme is further explained in combination with specific examples below. It is understood that these examples are intended to illustrate and not to limit the scope of the present disclosure. Conditions of implementation used in the examples can be further adjusted according to the conditions of the specific manufacturer. Conditions of implementation not specified are usually those used in routine experiments.
[0079] The present disclosure is illustrated by example rather than by giving restrictions. It should be noted that the references to one or one kind in this public document do not necessarily refer to the same specific implementation, but to at least one.
[0080] The various aspects of the disclosure are described below. However, it is obvious to a technician in the field that the disclosure may be implemented on the basis of only some or all aspects of the disclosure. For illustrative purposes, the specific serial numbers, materials and configurations are given to enable a thorough understanding of the disclosure. However, it will be obvious to a technician in the field that the disclosure can be implemented without the need for specific details. In other cases, well-known features are omitted or simplified in order not to obscure the disclosure.
[0081] The operations are described sequentially as separate steps and in such manner as best contributes to the understanding of the disclosure. However, a description of order should not be interpreted to imply that these operations are necessarily sequence-dependent.
[0082] The various examples will be illustrated in terms of typical types of reactants. It will be obvious to a technician in the field that the present disclosure may be implemented using any number of reactants of different kinds, not only those reactants given here for illustrative purposes. It will also be evident that the present disclosure is not limited to any particular mixed example.
Examples 1-8
Preparation of ZnCo DMC Catalyst
[0083] The parameters are shown in Table 1.
[0084] The cobalt salt and zinc salt of a certain mass is weighed, dissolved in water-based solvent and stirred continuously. Inorganic acids and organic acids are added and stirred for several hours at temperature i), and precipitation continued to form. The turbid liquid was drained and dried to obtain a filter cake. The filter cake was rinsed and washed again with water-based solvent at temperature ii). After stirring for several hours, the filter cake was extracted and dried to obtain the filter cake. The above steps of rinsing, rinsing and drying were repeated several times at temperature ii) until the liquid pH of the system in the range of 6 to 7. The solid product was further dried at 80 to 100 C. under vacuum condition to obtain the final catalyst. Before use, the catalyst was processed into powder particles by mechanical grinding under anhydrous drying condition.
TABLE-US-00001 TABLE 1 Example Example Example Example Example Example Example Example Parameters 1 2 3 4 5 6 7 8 cobalt salt potassium sodium potassium sodium potassium sodium potassium sodium species hexa- hexa- hexa- hexa- hexa- hexa- hexa- hexa- cyano- cyano- cyano- cyano- cyano- cyano- cyano- cyano- cobaltate cobaltate cobaltate cobaltate cobaltate cobaltate cobaltate cobaltate (III) (III) (III) (III) (III) (III) (III) (III) zinc salt zinc zinc zinc zinc zinc zinc zinc zinc species chloride bromide iodide sulfate acetate chloride bromide chloride molar ratio of 1:5 1:4 1:3 1:2 2:1 3:1 4:1 5:1 cobalt salt to zinc salt Water solvent water + water + water + water + water water + water + water + type methanol ert- ethanol propyl butanol pentanol ethanol butanol alcohol mass ratio of 1:1 1:5 1:10 1:20 1:50 1:100 1:200 1:10 total metal salt mass/aqueous solvent inorganic acid diluted diluted diluted diluted diluted diluted diluted diluted species sulfuric hydro- sulfuric hydro- sulfuric hydro- sulfuric hydro- acid chloric acid chloric acid + chloric acid + chloric acid acid diluted acid diluted acid hydro- hydro- chloric chloric acid acid pH of inorganic 1 2 3 4 5 0 1 2 acid organic acid succinic glutaric phthalan- iminodi- pyro- butane- succinic glutaric species acid acid dione acetic mellitic tetra acid acid acid acid carboxylic and and acid phthalan- succinic dione acid moles of 1:5 5:1 1:3 3:1 1:8 8:1 1:10 10:1 inorganic acid/moles of organic acid total moles of 1:4 4:1 1:5 5:1 1:10 10:1 1:2 2:1 metal salt/total moles of acid Step i) 10 100 20 60 80 40 80 60 temperature ( C.) Step ii) 80 60 40 20 100 10 80 60 temperature ( C.) Step i) time 2 3 6 1 5 3 4 3 Step i) time 12 6 3 5 10 8 2 4
Examples 9-18
[0085] All reaction conditions, parameters and product parameters are shown in Table 2. The reaction steps are summarized as follows:
[0086] The DMC catalyst prepared in Examples 1 to 8 is suspended in initiators and epoxides in a premixed container, so that the setting concentration of the catalyst is reached in the mixture. The components are mixed for a certain time at the specified temperature and pressure, and the mixture does not react. The mixed suspension is pumped from the mixer to the continuous reactor at a suitable flow rate. The continuous reactor is controlled at a specified reaction temperature and pressure. Each component remains in the continuous reactor for a specified retention period. The products (polycarbonate polyether alcohol and diverse cyclic propylene carbonate and unreacted epoxide) are collected in a container. The crude product is taken for .sup.1HnmR (nuclear magnetic resonance) spectroscopy, characterization and calculated the proportion of the polymer and cyclic carbonate products. The .sup.1HnmR test is carried again after polymer purification, to calculate the ratio of the polycarbonate and polyether linkages on the backbone of the polymer products. For example, the polymer chains only comprise two kinds of structure of polycarbonate and polyether, whose total percentage is 100%. The average molecular weight and molecular weight distribution of the polymer is determined by gel permeation chromatography (GPC). The results are shown in Table 2. The concentration of catalyst in turbid solution (wt %) is the mass ratio of catalyst to epoxide mentioned above.
TABLE-US-00002 TABLE 2 Example Example Example Example Example Example Example Example Example Example Parameters 9 10 11 12 13 14 15 16 17 18 catalyst source .sup.1 Example example Example Example Example Example Example Example Example Example 1 2 3 4 5 6 7 8 1 2 epoxide propyl- ethylene 1,2- 2,3- styrene cyclo- epichloro- pro- pro- propylene eneoxide oxide epoxy- epoxy oxide hexene hydrin pylene pylene oxide butane butane oxide oxide oxide initiator glycol glycerinum pentaery- adipic dode- terephthalic phtha- pyro- hydro- resorcinol thritol acid canedioic acid landione catechol quinone acid molar ratio 1:50 1:60 1:80 1:100 1:60 1:90 1:80 1:200 1:70 1:20 of initiator/ epoxide 2 catalyst 0.05 0.5 5 0.06 0.08 0.1 0.15 0.01 0.5 0.05 concentration in turbid liquid (wt %) premixed 0.1 2 0.2 1 0.2 0.4 0.6 0.3 0.5 0.2 pressure (MPa) Premixed 10 60 30 50 40 30 20 30 25 30 temperature ( C.) premixed 0.1 12 1 6 1 3 2 2 3 4 time (hour) reaction 150 50 120 60 110 70 100 80 90 80 temperature ( C.) reaction 20 1 15 2 10 3 6 4 4 5 pressure (MPa) mean detention 0.5 10 1 8 3 6 4 5 3 5 time (h) Epoxide 60 90 56 88 65 62 78 86 73 92 conversion.sup.3 (%) Molar 28 3 26 5 23 9 19 12 17 13 percentage of cyclic carbonate.sup.4 (%) Molar 55 91 65 89 58 88 60 71 66 68 percentage of polycarbonate linkage in polymer's backbone.sup.5 (%) Mn.sup.6 0.5 0.8 1.2 1.8 1.0 1.6 1.3 2.0 1.3 0.3 (kg/mol) PDI7 2.01 1.21 1.98 1.33 1.85 1.39 1.76 1.41 1.66 1.55 .sup.1 Catalysts were prepared from Table 1. .sup.2 Molar ratio of initiator versus epoxide when feeding the raw material in the reaction. .sup.3 Epoxide conversion: After the specified reaction time, the conversion rate of the cyclic oxides is calculated according to .sup.1HnmR of the crude products. .sup.4 It refers to the molar percentage of cyclic carbonate in its mixed product with polymer. This is calculated according to .sup.1HnmR of the mixed product. .sup.5 It refers to the molar percentage of polycarbonate linkage in polymer's backbone, and it is calculated according to .sup.1HnmR of the product. .sup.6M.sub.n refers to number average molecular weight, and it is determined by gel permeation chromatography (GPC). .sup.7PDI refers to polydispersity index, and it is determined by GPC.
[0087] From the above examples shows that ZnCo DMC catalysts prepared by the method of the disclosure show higher catalytic activity (1 to 2 hours in reaction time, epoxide conversion rate greater than 50%) in a high feeding proportion of initiator (1/50 to 1/90 of epoxide in molar ratio), and the mass ratio of catalyst to epoxide feeling less than 1/2000, at a higher reaction temperature (90 to 100 C.), the synthesized polymer contained a higher proportion of polycarbonate linkages (molar percentage>50%). The higher proportion of polycarbonate linkages in such polyols can endure polyurethane materials higher Young's modulus, better water resistance, weather resistance and other properties when used as raw materials to synthesize polyurethane materials.
[0088] The .sup.1HnmR hydrogen spectrum of the product of Example 17 is shown in
Comparative Example 1
[0089] According to Chinese patent CN1299300A released an acid treatment method of double metal cyanide complex catalyst preparation for catalyst number D1. Compared with the catalyst prepared in the Example 1 of the present disclosure, the reaction conditions are the same with that in the Example 9. The polyether polyol prepared by catalyst D1 does not comprise polycarbonate linkages in the polymer's backbone, no fixation and utilization effect of carbon dioxide, and no catalyst selectivity compared with the catalyst of the present disclosure.
[0090] The method is essentially different from the disclosure. Firstly, the timing of the addition of the modified acid is different. The DMC catalyst in Chinese patent CN1299300A is already synthesized in advance, and the protic acid is added before the polymerization reaction, which is equivalent to an improvement of the polymerization process. However, in the present disclosure the mixed acid must be added in the synthesis process of DMC catalyst, and in addition to protic acid, the aprotic acid must also be added at the same time (i.e., the organic acid proposed in the disclosure), so as to achieve better catalytic activity and selectivity of the disclosure through the synergistic effect of mixed acid. Secondly, only protic acid is added in the patent, while the mixed acid is added in the present disclosure (including protic acid and inorganic aprotic acid), which has different types of acids with different effects.
Comparative Example 2
[0091] In accordance with the patent WO2011160797 released an improved method for DMC catalysts and prepared catalyst number D5. Compared with the catalyst prepared in the Example 5 of the present disclosure, the reaction conditions are the same with that in Example 13. The polyether polyol prepared by catalyst D5 comprises 40% of ring products. The polymeric main chains comprise 30% polycarbonate linkages and 70% polyether linkages. Compared with the results of Example 13 of the disclosure, the selectivity of the polymer product is lower than that of the disclosure, and the selectivity of carbon dioxide fixation is much lower.
[0092] The method is fundamentally different from the disclosure. The timing of the addition of modified acid is different. The DMC catalyst of patent WO2011160797 has been synthesized in advance, and the addition of protic acid is prior to the polymerization reaction, which is equivalent to an improvement of the polymerization process. However, in the present disclosure the mixed acid must be added in the synthesis process of DMC catalyst, and in addition to protic acid, the aprotic acid must also be added at the same time (i.e., the organic acid proposed in the disclosure), so as to achieve better catalytic activity and selectivity of the disclosure.
Comparative Example 3
[0093] The same method as in Example 1 was used to prepare the ZnCo DMC catalyst. The only difference was that only protic acids (in the case of diluted sulfuric acid) were used for modification without the addition of organic acids.
[0094] Potassium hexacyanocobaltate (III) and zinc chloride (molar ratio 1:5) is weighed, and added to the blend solvent of water and methanol with the equivalent weight to metal salts. After being stable and uniform, diluted sulfuric acid (pH 1, molar ratio of metal salt to acid 1:4) is added, stirred at 10 C., and no precipitation is generated. It can be clearly proved that under the condition of adding only inorganic acids without any organic acids, the system will not produce co-precipitation, that is, no catalyst will be generated.
Comparative Example 4
[0095] The same method as in Example 1 was used to prepare the ZnCo DMC catalyst. The only difference was that only organic acids (succinic acid as an example) were used for modification without the addition of inorganic protic acids.
[0096] Potassium hexacyanocobaltate (III) and zinc chloride (molar ratio 1:5) is weighed and added to the blend solvent of water and methanol with the equivalent weight to metal salts. After being stable and uniform, succinic acid (molar ratio of metal salt to acid is 1:4) was added and stirred at 10 C. for 2 hours, and precipitation continued to form. The turbidity liquid was drained and dried to obtain a filter cake. The filter cake was pulped and washed with water-based solvent. After stirring at 80 C. for 12 hours, the filter cake was extracted and dried to obtain the filter cake. The process was repeated several times until the pH of the liquid phase of the system was 6 to 7. The solid product was further dried under the vacuum condition of 80 C. to obtain the final catalyst. Before use, the catalyst was processed into powder particles by mechanical grinding under the condition of anhydrous drying.
[0097] When the catalyst was used to catalyze the polymerization under the reaction conditions of Example 9, it showed no activity. It is indicated that the system could generate precipitated metal coordination compounds when only organic acids were added, but without the synergistic modification of organic acids, the precipitate obtained above had no catalytic activity for the polymerization reaction.
[0098] The Comparative Example 3 and 4 indicate that when preparing the DMC catalyst of the disclosure, it is necessary to use organic acids and inorganic acids at the same time to modify and prepare the catalyst. Both kinds of acids are indispensable, and DMC catalyst for effective catalytic polymerization can not be obtained if one kind of acid is used for modification alone.
Comparative Example 5
[0099] The same method as Example 1 was used to prepare the ZnCobalt DMC catalyst. The only difference being that the diluted hydrochloric acid pH of 6 was used.
Modified with the Mixture of Diluted Hydrochloric Acid and Glutaric Acid
[0100] Sodium hexacyanocobaltate (III) and zinc bromide (molar ratio 1:4) were weighed and added into the blend solvent of the water and tert-butanol with the mass 5 times higher than that of metal salt, and stirred. After being stable and uniform, the mixed acid of diluted hydrochloric acid (pH=6) and glutaric acid (molar ratio of metal salt to acid is 4:1, molar ratio of diluted hydrochloric acid to glutaric acid is 5:1) are added. After stirring at 100 C. for 3 hours, precipitation continues to form. The turbid liquid was drained and dried to obtain a filter cake. The filter cake was pulped and washed with water-based solvent again. After stirring at 60 C. for 6 hours, the filter cake was extracted and dried to obtain the filter cake. The process was repeated several times until the pH of the liquid phase of the system was 6 to 7. The solid product was further dried under the vacuum condition of 80 C. to obtain the final catalyst. Before use, the catalyst was processed into powder particles by mechanical grinding under the condition of anhydrous drying.
[0101] The obtained catalyst was used to catalyze the polymerization reaction under the reaction conditions of Example 10, and the measured conversion rate was only about 5%. The polymer product was characterized by .sup.1HnmR to contain 85% polyether structure and 15% polycarbonate structure. It is proved that the catalyst has some activity, but the activity and selectivity are poor. The activity was much lower than that of the catalyst in Example 10, where the conversion was 90%. The polycarbonate structure was 91%, and the polyether structure was 9%. The results showed that the acid could not reduce the crystal structure of the catalyst when the pH value of inorganic protic acid was >5, that is, the acid was weak, and the activity and selectivity of the catalyst were reduced.
Comparative Example 6
[0102] The same method as in Example 2 was used to prepare the ZnCo DMC catalyst. The only difference was that the diluted hydrochloric acid with a pH of 1 was used.
Modified with the Mixture of Diluted Hydrochloric Acid and Glutaric Acid (Molar Ratio 5:1)
[0103] No precipitate and catalyst were achieved. The results show that when the pH value of the added inorganic protic acid is less than 0, the acid is too strong. It will destroy the coordination and bridging of the metal atoms, and can not generate the catalyst normally.
Comparative Example 7
[0104] The same method as in Example 2 for preparing the ZnCo DMC catalyst was used. The only difference was that the zinc salt in this method is substituted with a metal salt (cadmium bromide) as a third metal (in the case of cadmium) besides zinc and cobalt, that is, the zinc is substituted with a third metal.
Modified with the Mixture of Diluted Hydrochloric Acid and Glutaric Acid
[0105] Sodium hexacyanocobaltate (III) and cadmium bromide (molar ratio 1:4) were weighed and added into the blend solvent of the water and tert-butanol with the mass 5 times higher than that of metal salt, and stirred. After being stable and uniform, the mixed acid of diluted hydrochloric acid (pH=2) and glutaric acid (molar ratio of metal salt to acid is 4:1, molar ratio of diluted hydrochloric acid to glutaric acid is 5:1) are added. After stirring at 100 C. for 3 hours, precipitation continues to form. The turbid liquid was drained and dried to obtain a filter cake. The filter cake was pulped and washed with water-based solvent again. After stirring at 60 C. for 6 hours, the filter cake was extracted and dried to obtain the filter cake. The process was repeated several times until the pH of the liquid phase of the system was 6 to 7. The solid product was further dried under the vacuum condition of 80 C. to obtain the final catalyst. Before use, the catalyst was processed into powder particles by mechanical grinding under the condition of anhydrous drying.
[0106] When the catalyst was used for the polymerization under the reaction conditions of Example 10, it showed no activity, indicating that the precipitate obtained by replacing metal zinc with other metals had no catalytic activity for the polymerization.
Comparative Example 8
[0107] The preparation of the ZnCo DMC catalyst is done in the same way as in Example 2, with the only difference being that the cobalt salt in this method is replaced by a metal salt (sodium tetracyanonickelate) as a third metal (in the case of metal nickel) besides zinc and cobalt, that is, the cobalt metal is replaced by a third metal.
Modified with the Mixture of Diluted Hydrochloric Acid and Glutaric Acid
[0108] Sodium tetracyanonickelate and zinc bromide (molar ratio 1:4) were weighed and added into the blend solvent of the water and tert-butanol with the mass 5 times higher than that of metal salt, and stirred. After being stable and uniform, the mixed acid of diluted hydrochloric acid (pH=2) and glutaric acid (molar ratio of metal salt to acid is 4:1, molar ratio of diluted hydrochloric acid to glutaric acid is 5:1) are added. After stirring at 100 C. for 3 hours, precipitation continues to form. The turbid liquid was drained and dried to obtain a filter cake. The filter cake was pulped and washed with water-based solvent again. After stirring at 60 C. for 6 hours, the filter cake was extracted and dried to obtain the filter cake. The process was repeated several times until the pH of the liquid phase of the system was 6 to 7. The solid product was further dried under the vacuum condition of 80 C. to obtain the final catalyst. Before use, the catalyst was processed into powder particles by mechanical grinding under the condition of anhydrous drying.
[0109] When the catalyst was used for the polymerization under the reaction conditions of Example 10, it showed no activity, indicating that the precipitate obtained by replacing cobalt metal with other metals had no catalytic activity for the polymerization reaction.
Comparative Example 9
[0110] The preparation method of the ZnCo DMC catalyst is the same as that used in Example 2. The only difference is that in addition to the zinc and cobalt, a metal salt (ferric chloride) as a third metal (in the case of metal ferrum) is added for synthesis to prepare the catalyst comprising the three metal elements.
Modified with the Mixture of Diluted Hydrochloric Acid and Glutaric Acid
[0111] Sodium hexacyanocobaltate (III), zinc bromide and ferric chloride (molar ratio 1:4:1) were weighed and added into the blend solvent of the water and tert-butanol with the mass 5 times higher than that of metal salt, and stirred. After being stable and uniform, the mixed acids of diluted hydrochloric acid (pH=2) and glutaric acid (molar ratio of metal salt to acid is 4:1, molar ratio of diluted hydrochloric acid to glutaric acid is 5:1) are added. After stirring at 100 C. for 3 hours, precipitation continues to form. The turbid liquid was drained and dried to obtain a filter cake. The filter cake was pulped and washed with water-based solvent again. After stirring at 60 C. for 6 hours, the filter cake was extracted and dried to obtain the filter cake. The process was repeated several times until the pH of the liquid phase of the system was 6 to 7. The solid product was further dried under the vacuum condition of 80 C. to obtain the final catalyst. Before use, the catalyst was processed into powder particles by mechanical grinding under the condition of anhydrous drying.
[0112] The obtained catalyst was catalyzed for the polymerization reaction under the reaction conditions of Example 10, and the measured conversion was only about 3%. The polymer product was characterized by 1HNMR to contain 90% polyether structure and only 10% polycarbonate structure. It is proved that the catalyst has some activity, but the activity and selectivity are poor. The activity was much lower than that of the catalyst in Example 10, where the conversion was 90%. The polycarbonate structure was 91%, and the polyether structure was 9%. The results show that the activity and selectivity of the catalyst are greatly reduced when the third metal is added, although the catalyst still retains some activity.
Comparative Example 10
[0113] The preparation of the ZnCo DMC catalyst is the same as in Example 2, with the only difference being that diluted hydrochloric acid is replaced by other kinds of inorganic protic acids (in case of hydrobromic acid) for the catalyst preparation.
Modified with the Mixture of Hydrobromic Acid and Glutaric Acid
[0114] Sodium hexacyanocobaltate (III) and zinc bromide (molar ratio 1:4) were weighed and added into the blend solvent of the water and tert-butanol with the mass 5 times higher than that of metal salt, and stirred. After being stable and uniform, hydrobromic acid (pH=2) and glutaric acid (molar ratio of metal salt to acid is 4:1, molar ratio of hydrobromic acid to glutaric acid is 5:1) are added. After stirring at 100 C. for 3 hours, precipitation continues to form. The turbid liquid was drained and dried to obtain a filter cake. The filter cake was pulped and washed with water-based solvent again. After stirring at 60 C. for 6 hours, the filter cake was extracted and dried to obtain the filter cake. The process was repeated several times until the pH of the liquid phase of the system was 6 to 7. The solid product was further dried under the vacuum condition of 80 C. to obtain the final catalyst. Before use, the catalyst was processed into powder particles by mechanical grinding under the condition of anhydrous drying.
[0115] The obtained catalyst was used to catalyze the polymerization reaction under the reaction conditions of Example 10, and the measured conversion was only about 5%. The products were mainly cyclic carbonates with small molecules, and almost no polymer products were achieved according to the 1HNMR characterization. The results showed that the catalytic activity of the catalyst was very low and there was almost no polymer selectivity when the diluted hydrochloric acid was replaced by other inorganic protic acids.
Comparative Example 11
[0116] The preparation of the ZnCo DMC catalyst is the same as in Example 2, with the only difference being that glutaric acid is replaced by other kinds of organic acids (in case of adipic acid) to prepare the catalyst.
Modified with the Mixture of Diluted Hydrochloric Acid and Adipic Acid
[0117] Sodium hexacyanocobaltate (III) and zinc bromide (molar ratio 1:4) were weighed and added into a blend solvent of the water and tert-butanol with the mass 5 times higher than that of metal salt, and stirred. After being stable and uniform, diluted hydrochloric acid (pH=2) and the mixed acid of adipic acid (molar ratio of metal salt to acid is 4:1, molar ratio of diluted hydrochloric acid to adipic acid is 5:1) are added. After stirring at 100 C. for 3 hours, precipitation continues to form. The turbid liquid was drained and dried to obtain a filter cake. The filter cake was pulped and washed with water-based solvent again. After stirring at 60 C. for 6 hours, the filter cake was extracted and dried to obtain the filter cake. The process was repeated several times until the pH of the liquid phase of the system was 6 to 7. The solid product was further dried under the vacuum condition of 80 C. to obtain the final catalyst. Before use, the catalyst was processed into powder particles by mechanical grinding under the condition of anhydrous drying.
[0118] The obtained catalyst was used to catalyze the polymerization reaction under the reaction conditions of Example 10, and the measured conversion was only about 5%. The products were mainly cyclic carbonates with small molecules, and almost no polymer products were achieved according to the 1HNMR characterization. The results showed that the catalytic activity of the catalyst was very low and there was almost no polymer selectivity when the diluted hydrochloric acid was replaced by other inorganic protic acids.
Comparative Example 12
[0119] The same method as in Example 2 was used to prepare ZnCo DMC catalysts. The only difference was that the molar ratio of inorganic protic acids to organic acids was 11:1.
Modified with the Mixture of Hydrobromic Acid and Glutaric Acid
[0120] Sodium hexacyanocobaltate (III) and zinc bromide (molar ratio 1:4) were weighed and added into the blend solvent of the water and tert-butanol with the mass 5 times higher than that of metal salt, and stirred. After being stable and uniform, the mixed acid of diluted hydrochloric acid (pH=2) and glutaric acid (molar ratio of metal salt to acid is 4:1, molar ratio of diluted hydrochloric acid to glutaric acid is 11:1) are added. After stirring at 100 C. for 3 hours, the precipitate can not be obtained, and the catalyst can not be synthesized normally. The results show that when the molar ratio of inorganic protic acid to organic acid is greater than 10:1, the coordination and bridging of metals will be destroyed and the catalyst cannot be synthesized normally.
Comparative Example 13
[0121] The same method as in Example 2 was used to prepare ZnCo DMC catalysts. The only difference was that the molar ratio of inorganic protic acids to organic acids was 1:11.
Modified with the Mixture of Hydrobromic Acid and Glutaric Acid
[0122] Sodium hexacyanocobaltate (III) and zinc bromide (molar ratio 1:4) were weighed and added into the blend solvent of the water and tert-butanol with the mass 5 times higher than that of metal salt, and stirred. After being stable and uniform, the mixed acid of diluted hydrochloric acid (pH=2) and glutaric acid (molar ratio of metal salt to acid is 4:1, diluted hydrochloric acid to glutaric acid is 1:11) are added. After stirring at 100 C. for 3 hours, precipitation continues to form. The turbid liquid was drained and dried to obtain a filter cake. The filter cake was pulped and washed with water-based solvent again. After stirring at 60 C. for 6 hours, the filter cake was extracted and dried to obtain the filter cake. The process was repeated several times until the pH of the liquid phase of the system was 6 to 7. The solid product was further dried under the vacuum condition of 80 C. to obtain the final catalyst. Before use, the catalyst was processed into powder particles by mechanical grinding under the condition of anhydrous drying.
[0123] It is indicated that the catalyst had no activity when the molar ratio of inorganic protic acid and organic acid was less than 1:10.
Comparative Example 14
[0124] A: Preparation of metal catalysts according to the patented method: The mixture of ethylene glycol of 41 equivalent weight and water of 4 equivalent weight is added into the tank with agitator at room temperature and pressure. The 1.5 equivalent weight of potassium hexacyanocobaltate (III) and zinc chloride (molar ratio of 1:5) is added to the mixture, stirred and dissolved. 3.8 equivalent weight of diluted sulfuric acid and succinic acid mixture (molar ratio of 1:5) is added, stirred and mixed. Then 2.4 equivalent weight of tetrabutyl titanate is added and stirred for 30 minutes to dissolve, and thus obtained catalyst D14-A. Compared with the catalyst prepared in the Example 1 of the present disclosure, the reaction condition is the same as that in the Example 9, while the catalyst D14-A has no catalytic activity for the copolymerization of carbon dioxide with propylene oxide.
[0125] B: According to the method preparation of metal catalysts released in A patent: The only difference is that the replace of tetrabutyl titanate with tetrabutyl zirconate replace, and the catalyst preparation for D14-B. Compared with the catalyst in the Example 1 of the present disclosure, the reaction condition is the same as that in the Example 9, while the catalyst D14-B has no catalytic activity for the copolymerization of carbon dioxide with propylene oxide.
[0126] C: According to the method preparation of metal catalysts released in A patent: The only difference is that the replace of tetrabutyl titanate with tetrabutyl hafniate, and the catalyst preparation for D14-C. Compared with the catalyst prepared in the Example 1 of the present disclosure, the reaction condition is the same as that in the Example 9, while the catalyst D14-C has no catalytic activity for the copolymerization of carbon dioxide with propylene oxide.
[0127] D: According to the method preparation of metal catalysts released in A patent: The only difference is that the replace of potassium hexacyanocobaltate (III) with cobalt chloride, and the catalyst preparation for D14-D. Compared with the catalyst prepared in the Example 1 of the present disclosure, the reaction condition is the same as that in the Example 9, while the catalyst D14-D has no catalytic activity for the copolymerization of carbon dioxide with propylene oxide.
[0128] In summary, all the following conditions must be strictly met in order to produce a catalyst with the technical effect of the present disclosure: The catalyst is obtained by the reaction of water-soluble metal salt of zinc and cobalt in water-soluble solvent, and the water-soluble metal salt of cobalt is cobalt cyanide salt. The catalyst is synthesized by mixed acid modification, and the mixed acid comprises at least one organic acid and at least one water-soluble inorganic acid, wherein: the water-soluble inorganic acid is selected from diluted sulfuric acid and diluted hydrochloric acid, with pH value being range of 0 to 5. The organic acids are selected any one or any variety from succinic acid, glutaric acid, phthalic acid, iminodiacetic acid, pyromellitic acid, butanetetracarboxylic acid. The water-soluble inorganic acid and organic acid is in a molar ratio of 1:10 to 10:1.
[0129] Technical effect of the present disclosure refers to: Under the common industrial conditions with the mass ratio of catalyst and epoxide monomer less than 1/1000, the catalyst shows higher catalytic activity (1 to 2 hours in reaction time, monomer conversion rate greater than 50%) with a higher amount ratio of initiator feeding (1/50 to 1/90 of the epoxide monomer feeding in molar) and a higher reaction temperature (90 to 100 C.), and the synthetic polymer structure comprises a higher proportion of polycarbonate structure (molar percentage>50%).
[0130] The above is only the preferred implementation mode of the present disclosure. It should be noted that for ordinary technicians in the technical field, without deviating from the principles of the disclosure, a number of improvements and refinements may be made, which shall also be considered as the scope of protection of the present disclosure.