A trinuclear cobalt compound, an electron-withdrawing multi-component polyester material and a preparation method thereof

Abstract

The present invention relates to the field of polymer technology, specifically to a trinuclear cobalt compound, an electron-withdrawing multinary polyester material and a preparation method thereof. The trinuclear cobalt compound provided by the present invention is a compound of a structure shown in formula (IV) with a triazine ring as a connecting group, which can catalyze the polymerization reaction of at least one of a cyclic acid anhydride and carbon dioxide and an electron-withdrawing epoxide to obtain an electron-withdrawing multinary polyester material with controllable molecular weight and regular sequence structure. The preparation method of the electron-withdrawing multinary polyester material provided by the present invention has good catalytic selectivity and high conversion rate. Experiments show that when the trinuclear cobalt compound of the present invention is used as a catalyst for polymerization reaction to prepare an electron-withdrawing multinary polyester material, the conversion rate of the cyclic acid anhydride reaches 100%, the conversion rate of styrene oxide is above 60%, and the obtained electron-withdrawing multinary polyester material has a regular sequence and a controllable molecular weight of 24.8kDa.

Description

Technical Field

[0001] The invention relates to the technical field of polymers, in particular to a trinuclear cobalt compound, an electron-withdrawing multi-component polyester material and a preparation method thereof. Background Art

[0002] With the gradual implementation of the plastic ban, the synthesis and application of degradable polymer materials have attracted more and more attention. Polyester and polycarbonate are two important types of degradable polymer materials, which have the advantages of wide raw material sources, adjustable material properties and excellent biocompatibility. They have been widely used in disposable tableware, packaging materials, 3D printing materials and biological tissue engineering.

[0003] Styrene oxide is a type of epoxy monomer synthesized by the epoxidation reaction of styrene. It has the advantages of wide sources, low price and stable structure. Polystyrene carbonate (PSC) obtained by the catalytic copolymerization of styrene oxide and CO2 has a high glass transition temperature and mechanical strength; and polyester materials with diverse structures can be prepared by the copolymerization of styrene oxide and cyclic anhydride. By designing and adjusting the monomer structure and feed ratio in the multi-copolymer system of styrene oxide, cyclic anhydride and CO2, degradable polyester materials suitable for different application fields can be prepared. However, the electron-withdrawing effect of the benzene ring group in styrene oxide makes it easy to obtain cyclic carbonate products when it reacts with CO2, and the molecular weight of the resulting polymer is low, and the catalytic selectivity and chain segment structure regularity are poor. Summary of the invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a trinuclear cobalt compound, an electron-withdrawing multinary polyester material and a preparation method thereof. The trinuclear cobalt compound provided by the present invention can catalyze the polymerization reaction of at least one of cyclic acid anhydride and carbon dioxide and an electron-withdrawing epoxide to obtain an electron-withdrawing multinary polyester material with controllable molecular weight and regular sequence structure, with good catalytic selectivity and high conversion rate.

[0005] The present invention provides a trinuclear cobalt compound having a structure of formula (IV):

[0006]

[0007] The R1 and R2 are independently selected from hydrogen, halogen, cyano, hydroxyl, nitro, substituted or unsubstituted C1-C 20 Alkyl, substituted or unsubstituted C6~C 30 Aryl, substituted or unsubstituted C2~C 30 Heteroaryl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 20 aryloxy, substituted or unsubstituted C3~C40 Siloxy, substituted or unsubstituted C1~C 20 Acyl, substituted or unsubstituted C2~C 20 Alkoxycarbonyl, substituted or unsubstituted C2~C 20 substituted or unsubstituted C2~C 20 Amide group, substituted or unsubstituted C2~C 20 Alkoxycarbonylamino, substituted or unsubstituted C7~C 20 aryloxycarbonylamino, substituted or unsubstituted C1~C 20 Sulfonamido, substituted or unsubstituted C1~C 20 Sulfonyl, substituted or unsubstituted C1~C 20 Alkylthio, substituted or unsubstituted C6~C 20 arylthio, substituted or unsubstituted C1~C 20 Heterocyclic thio, substituted or unsubstituted C1~C 20 ureide group, substituted or unsubstituted C3~C 40 The silyl group or the R1 and R2 independently form a condensed ring with the benzene ring to which they are connected; the hydrogen in the present invention includes protium, deuterium or tritium;

[0008] The X is selected from substituted or unsubstituted acetate, substituted or unsubstituted phenoloxy, substituted or unsubstituted benzoate, substituted or unsubstituted benzenesulfonate, halogen or nitro.

[0009] In certain embodiments of the present invention, R1 and R2 are independently selected from hydrogen, halogen, substituted or unsubstituted C1-C 20 Alkyl, substituted or unsubstituted C6~C 30 Aryl, substituted or unsubstituted C1~C 20 The alkoxy group is preferably selected from substituted C1 to C 10 Alkyl, substituted C6~C 15 Aryl, substituted C1~C 10 In one embodiment, R1 and R2 are independently selected from hydrogen or tert-butyl.

[0010] In certain embodiments of the present invention, X is preferably selected from fluorine, chlorine, bromine, iodine, nitro, acetate, trifluoroacetate, p-toluenesulfonate, p-toluenesulfonate, 2,4-dinitrophenoloxy, 3,5-dinitrophenoloxy, p-nitrophenoloxy or o-nitrophenoloxy, more preferably selected from chlorine, nitro, acetate, trifluoroacetate or 2,4-dinitrophenoloxy.

[0011] The present invention provides a method for preparing the above trinuclear cobalt compound, comprising:

[0012] The compound having the structure shown in formula (V), sodium hydride, a cobalt-containing compound and an X-containing compound are reacted to obtain a trinuclear cobalt compound having the structure of formula (IV);

[0013]

[0014] In the X-containing compound, the selection range of X is the same as that of the compound of the structure represented by the aforementioned formula (IV), and will not be described in detail.

[0015] In the compound of the structure shown in formula (V), the selection range of R1 and R2 is the same as the selection range of R1 and R2 described in the compound of the structure shown in formula (IV) above, and will not be repeated here.

[0016] Specifically, the present invention reacts a compound of the structure shown in formula (V), sodium hydride and a cobalt-containing compound in a first solvent under an anhydrous and oxygen-free environment to obtain a solid product; the obtained solid product and a compound containing X are reacted in a second solvent under an aerobic environment to obtain a trinuclear cobalt compound having a structure of formula (IV). In one embodiment, the compound of the structure shown in formula (V) is added to tetrahydrofuran in a nitrogen environment, sodium hydride is slowly added, and then the cobalt-containing compound is slowly added, and the reaction is stirred at room temperature for 2 hours, and then filtered to obtain a solid; the obtained solid and the compound containing X are dissolved in dichloromethane, oxygen is introduced, and the reaction is stirred for 1 hour, and the solvent is spin-dried to obtain a trinuclear cobalt compound having a structure of formula (IV).

[0017] In one embodiment, the cobalt-containing compound is selected from one or more of chromium dichloride, cobalt acetate or cobalt nitrate. In one embodiment, the molar ratio of the compound of the structure represented by formula (V) to the cobalt-containing compound is 1:3-4.

[0018] In certain embodiments of the present invention, the method for preparing the compound of the structure represented by the above formula (V) comprises:

[0019] The half amine compound having the structure of formula (VI) is reacted with the substituted salicylaldehyde having the structure of formula (VII) to obtain the compound having the structure represented by formula (V);

[0020]

[0021] In the substituted salicylaldehyde having the structure of formula (VII), the selection range of R1 and R2 is the same as the selection range of R1 and R2 described in the compound of the structure represented by the aforementioned formula (IV), and will not be repeated here.

[0022] Specifically, the present invention reacts a half-amine compound having a structure of formula (VI) with a substituted salicylaldehyde having a structure of formula (VII) in a solvent, and purifies the obtained solid to obtain the above-mentioned compound having a structure shown in formula (V). In one embodiment, the present invention adds a half-amine compound having a structure of formula (VI) and a substituted salicylaldehyde having a structure of formula (VII) to methanol, refluxes and stirs the reaction for 10 hours, and then removes the solvent in vacuo, and the obtained solid is purified by column chromatography to obtain the above-mentioned compound having a structure shown in formula (V).

[0023] In certain embodiments of the present invention, the method for preparing the half-amine compound having the structure of formula (VI) comprises: reacting a compound having the structure of formula (VIII) with a compound having the structure of formula (IX) to obtain the half-amine compound having the structure of formula (VI);

[0024]

[0025] Specifically, the present invention performs azeotropic dehydration on a compound having a structure of formula (VIII) and a compound having a structure of formula (IX), and purifies the obtained solid to obtain the above-mentioned half-amine compound having a structure of formula (VI). In one embodiment, the present invention dissolves the compound having a structure of formula (VIII) and a compound having a structure of formula (IX) in toluene, performs azeotropic dehydration reaction for 60 hours, and then vacuum removes the solvent, dissolves the obtained solid in dichloromethane, drops n-hexane into it, and performs vacuum filtration to obtain the above-mentioned half-amine compound having a structure shown in formula (VI).

[0026] The trinuclear cobalt compound with a structure of formula (IV) provided by the present invention is prepared by reacting a compound with a structure shown in formula (V), sodium hydride, a cobalt-containing compound and an X-containing compound, and is used to catalyze the polymerization reaction of at least one of a cyclic acid anhydride and carbon dioxide and an electron-withdrawing epoxide, so as to obtain the electron-withdrawing multi-polyester material of the present invention with controllable molecular weight and regular sequence structure, and has good catalytic selectivity and high conversion rate.

[0027] The electron-withdrawing multi-polyester material provided by the present invention has a structure of formula (1):

[0028]

[0029] The 0≤m≤200; 0≤n≤300; the m and n are not 0 at the same time;

[0030] The Q is selected from

[0031] The R is selected from substituted or unsubstituted C1 to C 20 Alkyl, substituted or unsubstituted C6~C 30Aryl, substituted or unsubstituted C2~C 30 Heteroaryl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 20 aryloxy, substituted or unsubstituted C3~C 40 Siloxy, substituted or unsubstituted C1~C 20 Acyl, substituted or unsubstituted C2~C 20 Alkoxycarbonyl, substituted or unsubstituted C2~C 20 substituted or unsubstituted C2~C 20 Amide group, substituted or unsubstituted C2~C 20 Alkoxycarbonylamino, substituted or unsubstituted C7~C 20 aryloxycarbonylamino, substituted or unsubstituted C1~C 20 Sulfonamido, substituted or unsubstituted C1~C 20 Sulfonyl, substituted or unsubstituted C1~C 20 Alkylthio, substituted or unsubstituted C6~C 20 arylthio, substituted or unsubstituted C1~C 20 Heterocyclic thio, substituted or unsubstituted C1~C 20 ureide group, substituted or unsubstituted C3~C 40 of silyl, hydrogen, halogen, cyano or nitro.

[0032] In certain embodiments of the present invention, Q is preferably selected from

[0033] In certain embodiments of the present invention, R is preferably selected from hydrogen, halogen, nitro, substituted or unsubstituted C1-C 20 Alkyl, substituted or unsubstituted C6~C 30 Aryl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 20 aryloxy, substituted or unsubstituted C3~C 40 Siloxy, substituted or unsubstituted C1~C 20 Acyl, substituted or unsubstituted C2~C 20 Alkoxycarbonyl, substituted or unsubstituted C2~C 20 acyloxy, substituted or unsubstituted C3~C 40 The silyl group is more preferably selected from substituted or unsubstituted C1 to C 20 Alkyl, substituted or unsubstituted C1~C 20 alkoxy, hydrogen or halogen, more preferably selected from substituted or unsubstituted C1-C 10Alkyl, substituted or unsubstituted C1~C 10 The alkoxy group, cyano group, hydrogen, fluorine, chlorine or bromine group is most preferably selected from hydrogen, p-chlorine, m-chlorine, p-methyl, p-ethyl, p-methoxy, p-cyano.

[0034] In one embodiment, the specific structure of the electron-withdrawing multi-polyester material is shown in formula (I):

[0035]

[0036] The 0≤m≤200; 0≤n≤300; the m and n are not 0 at the same time;

[0037] In the electron-withdrawing multi-polyester material of the structure shown in formula (I), the selection range of Q is the same as the selection range of Q described in the compound of the structure shown in formula (1) above, and will not be repeated here.

[0038] The present invention provides a method for preparing the electron-withdrawing multi-component polyester material, comprising:

[0039] Under the action of a catalyst and an organic base, at least one of a cyclic acid anhydride and carbon dioxide of a structure represented by formula (III) is reacted with an electron-withdrawing epoxide of a structure represented by formula (2) to obtain an electron-withdrawing multi-polyester material of a structure represented by formula (1);

[0040] The catalyst is the above trinuclear cobalt compound having the structure of formula (IV);

[0041]

[0042] In the electron-withdrawing epoxide of the structure shown in formula (2), the selection range of R is the same as the selection range of R described in the compound of the structure shown in formula (1) above, and will not be repeated. In one embodiment, the electron-withdrawing epoxide of the structure shown in formula (2) is selected from styrene oxide.

[0043] In the cyclic anhydride of the structure shown in formula (III), the selection range of Q is the same as the selection range of Q in the compound of the structure shown in formula (1) above, and will not be repeated. In one embodiment, the cyclic anhydride of the structure shown in formula (III) is selected from phthalic acid, succinic anhydride or nadic anhydride.

[0044] Specifically, the present invention mixes the electron-withdrawing epoxide with a structure represented by formula (2), the cyclic acid anhydride with a structure represented by formula (III), the trinuclear cobalt compound with a structure represented by formula (IV) and an organic base, introduces carbon dioxide to react, and purifies after the reaction to obtain the electron-withdrawing multi-polyester material with a structure represented by formula (1); or, mixes the electron-withdrawing epoxide with a structure represented by formula (2), the cyclic acid anhydride with a structure represented by formula (III), the trinuclear cobalt compound with a structure represented by formula (IV) and an organic base to react, and purifies after the reaction to obtain the electron-withdrawing multi-polyester material with a structure represented by formula (1); or, mixes the electron-withdrawing epoxide with a structure represented by formula (2), the trinuclear cobalt compound with a structure represented by formula (IV) and an organic base, introduces carbon dioxide to react, and purifies after the reaction to obtain the electron-withdrawing multi-polyester material with a structure represented by formula (1).

[0045] In certain embodiments of the present invention, the electron-withdrawing epoxide of the structure shown in formula (2), the cyclic acid anhydride of the structure shown in formula (III), the trinuclear cobalt compound of the structure (IV) and the organic base are sequentially added into an anhydrous and oxygen-free reaction vessel, carbon dioxide is passed therein, and the reaction is heated and stirred. After the reaction, the reaction is cooled and then purified in methanol to obtain an electron-withdrawing multi-polyester material of the structure shown in formula (1); in the obtained electron-withdrawing multi-polyester material of the structure shown in formula (1), m and n are not 0.

[0046] In certain embodiments of the present invention, the electron-withdrawing epoxide with a structure represented by formula (2), the cyclic acid anhydride with a structure represented by formula (III), the trinuclear cobalt compound with a structure represented by formula (IV), and an organic base are sequentially added into an anhydrous and oxygen-free reaction vessel, and the reaction is carried out by heating and stirring. After the reaction, the reaction is cooled, and then purified in methanol to obtain an electron-withdrawing multi-polyester material with a structure represented by formula (1); in the obtained electron-withdrawing multi-polyester material with a structure represented by formula (1), m is not 0, and n is 0.

[0047] In certain embodiments of the present invention, the electron-withdrawing epoxide having the structure shown in formula (2), the trinuclear cobalt compound having the structure shown in formula (IV), and an organic base are sequentially added into an anhydrous and oxygen-free reaction vessel, carbon dioxide is passed therethrough, and the reaction is heated and stirred. After the reaction, the reaction is cooled, and then purified in methanol to obtain an electron-withdrawing multi-polyester material having the structure shown in formula (1); in the obtained electron-withdrawing multi-polyester material having the structure shown in formula (1), m is 0 and n is not 0.

[0048] In one embodiment, the organic base is selected from one or more of bis(triphenylphosphorane)ammonium chloride, 4-dimethylaminopyridine, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, N-methylimidazole, tricyclohexylphosphine, tetrabutylammonium chloride and tetrabutylammonium bromide. In one embodiment, the molar ratio of the catalyst to the organic base is 1:1-6, preferably 1:2-3. In one embodiment, the molar ratio of the total moles of the catalyst and the organic base to the cyclic anhydride and the electron-withdrawing epoxide is 1:100-1000:500-10000, preferably 1:100-500:500-2000.

[0049] In one embodiment, the pressure of the carbon dioxide is 0.1-5 MPa, preferably 1-2.5 MPa. In one embodiment, the reaction temperature is 25-120° C., preferably 25-50° C.; the reaction time is 0.5-120 h.

[0050] The present invention provides a trinuclear cobalt compound, an electron-withdrawing multinary polyester material and a preparation method thereof. The trinuclear cobalt compound provided by the present invention is a compound of a structure shown in formula (IV) with a triazine ring as a connecting group, which can catalyze the polymerization reaction of at least one of a cyclic acid anhydride and carbon dioxide and an electron-withdrawing epoxide to obtain an electron-withdrawing multinary polyester material with controllable molecular weight and regular sequence structure. The preparation method of the electron-withdrawing multinary polyester material provided by the present invention has good catalytic selectivity and high conversion rate. Experiments show that when the trinuclear cobalt compound of the present invention is used as a catalyst for polymerization reaction to prepare the electron-withdrawing multinary polyester material, the conversion rate of the cyclic acid anhydride reaches 100%, the conversion rate of styrene oxide is above 60%, and the obtained electron-withdrawing multinary polyester material has a regular sequence and a controllable molecular weight of 24.8kDa. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is the hydrogen nuclear magnetic resonance spectrum of the compound obtained in Example 2;

[0052] Figure 2 This is the nuclear magnetic resonance hydrogen spectrum of the oxidized styrene-based degradable polymer material obtained in Example 13. DETAILED DESCRIPTION

[0053] The present invention discloses a trinuclear cobalt compound, an electron-withdrawing multi-polyester material and a preparation method thereof. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve the same. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The method and application of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the method and application of this article without departing from the content, spirit and scope of the present invention to realize and apply the technology of the present invention.

[0054] The present invention will be further described below in conjunction with embodiments:

[0055] Example 1

[0056] The semi-amine compound of formula (VI) was synthesized according to the following synthetic route:

[0057]

[0058] The specific steps of the synthesis include: adding 5.52g of cyanuric chloride, 13.68g of cyclohexanediamine and 0.1g of p-toluenesulfonic acid to 150mL of toluene, and performing azeotropic dehydration reaction for 60h, and then vacuum-drying the toluene to obtain a viscous substance, dissolving it in dichloromethane, and then dripping it into 300mL of n-hexane, filtering and collecting the obtained solid and vacuum-drying it to obtain a semi-amine compound with a structure of formula (VI).

[0059] Example 2

[0060] The ligand compound of formula (V) was synthesized according to the following synthetic route:

[0061]

[0062] The specific steps of the synthesis include: adding 4.17 g of the half-amine compound obtained in Example 1 and 9.36 g of 3,5-di-tert-butyl salicylaldehyde to 100 mL of methanol, refluxing and stirring the reaction for 10 hours, and then vacuum-evacuating the solvent. The obtained solid is purified by column chromatography to obtain a ligand compound with the structure of formula (V).

[0063] The present invention uses nuclear magnetic resonance to analyze the ligand compound obtained in this embodiment to obtain its hydrogen spectrum, such as Figure 1 As shown, Figure 1 This is the H NMR spectrum of the compound obtained in Example 2. The results show that: 1H NMR (300MHz, CDCl3): δ = 13.6 (3H), 8.37 (3H), 7.35 (3H), 7.05 (3H), 4.68 (3H), 3.23 (3H), 2.23-1.36 (24H), 1.42 (27H), 1.29 (27H). The present invention uses a mass spectrometer to analyze the ligand compound obtained in this embodiment, and the results show that: m / z = 1066.8. The above analysis results show that the ligand compound prepared in this embodiment has the structure of formula (V), wherein R1 and R2 are both tert-butyl.

[0064] Example 3

[0065] The present invention adopts the technical solution of Example 2 to prepare the ligand, except that 3-tert-butyl salicylaldehyde is used in this example to replace the 3,5-di-tert-butyl salicylaldehyde in Example 2.

[0066] The present invention performs nuclear magnetic resonance hydrogen spectrum analysis and mass spectrum analysis on the obtained reaction product. The results show that the ligand compound prepared in this embodiment has a structure of formula (V), wherein R1 is H and R2 is tert-butyl.

[0067] Example 4

[0068] The present invention adopts the technical solution of Example 2 to prepare the ligand, except that salicylaldehyde is used in this example to replace the 3,5-di-tert-butyl salicylaldehyde in Example 2.

[0069] The present invention performs nuclear magnetic resonance hydrogen spectrum analysis and mass spectrum analysis on the obtained reaction product. The results show that the ligand compound prepared in this embodiment has a structure of formula (V), wherein R1 and R2 are H.

[0070] Example 5

[0071] The trinuclear cobalt compound of formula (IV) was synthesized according to the following synthetic route:

[0072]

[0073] The specific steps of the synthesis are as follows: In a nitrogen environment, 1.0668 g (1 mmol) of the ligand compound prepared in Example 2 was dissolved in 20 mL of tetrahydrofuran, 0.144 g (6 mmol) of sodium hydride was slowly added, and the mixture was stirred at room temperature for 0.5 h. Then 0.531 g (3 mmol) of cobalt acetate was slowly added, and the mixture was stirred at room temperature for 2 h, and then the insoluble matter was removed by filtration, and the filtrate was dried by rotary evaporation to obtain a solid.

[0074] 0.618 g (0.5 mmol) of the solid obtained above and 0.276 g (1.5 mmol) of 2,4-dinitrophenol were dissolved in 20 mL of dichloromethane, stirred for 1 h under oxygen flow, and the solvent was dried to obtain a trinuclear cobalt compound having the structure of formula (IV).

[0075] The present invention uses a mass spectrometer to analyze the trinuclear cobalt compound obtained in this example. The results show that: ESI-MS, m / z=1236.5 (-3*2,4-dinitrophenoloxy).

[0076] Example 6

[0077] The present invention adopts the technical method of Example 5 to prepare the trinuclear cobalt compound, except that acetic acid is used instead of 2,4-dinitrophenol in Example 5.

[0078] Example 7

[0079] The present invention adopts the technical method of Example 5 to prepare the trinuclear cobalt compound, except that the ligand obtained in Example 3 is used instead of the ligand in Example 2 in this example.

[0080] Example 8

[0081] The present invention adopts the technical method of Example 5 to prepare the trinuclear cobalt compound, except that the ligand obtained in Example 4 is used instead of the ligand in Example 2 in this example.

[0082] Example 9

[0083] 1.80g of styrene oxide, 0.444g of phthalic anhydride, 0.0178g of the trinuclear cobalt compound obtained in Example 5 and 0.0174g of bistriphenylphosphine ammonium chloride were sequentially added into a high-pressure reactor that had been dehydrated and deoxygenated at high temperature. The reactor was placed in a 40°C oil bath and heated with stirring for 5 hours, then cooled and a small amount of the reaction solution was dissolved in CDCl3 for characterization of the monomer conversion rate; the remaining reaction solution was dropped into methanol to purify the polymer product.

[0084] The present invention conducts the obtained reaction product 1 H-NMR analysis showed that phthalic anhydride was completely reacted; GPC test showed that the molecular weight of the obtained polymer was 15.3 kDa.

[0085] Example 10

[0086] 1.80g of styrene oxide, 0.3g of succinic anhydride, 0.0178g of the trinuclear cobalt compound obtained in Example 5 and 0.0084g of tetra-n-butylammonium chloride were sequentially added into a high-pressure reactor that had been dehydrated and deoxygenated at high temperature. The reactor was placed in a 60°C oil bath and heated with stirring for 5 hours, then cooled and a small amount of the reaction solution was dissolved in CDCl3 for characterization of the monomer conversion rate; the remaining reaction solution was dropped into methanol to purify the polymer product.

[0087] The present invention conducts the obtained reaction product 1 H-NMR analysis showed that the conversion rate of succinic anhydride was 80%. GPC test showed that the molecular weight of the obtained polymer was 7.5 kDa.

[0088] Embodiment 11

[0089] 2.40g of styrene oxide, 0.0178g of the trinuclear cobalt compound obtained in Example 5 and 0.0174g of bistriphenylphosphine ammonium chloride were sequentially added into a high-pressure reactor that had been dehydrated and deoxygenated at high temperature, and 2MPa of carbon dioxide gas was introduced into the reactor. The reactor was placed in a 30°C oil bath and heated and stirred for 3h, then cooled and a small amount of the reaction solution was dissolved in CDCl3 for characterization of the monomer conversion rate; the remaining reaction solution was dropped into methanol to purify the polymer product.

[0090] The present invention conducts the obtained reaction product 1 H-NMR analysis showed that the conversion rate of styrene oxide was 70% and the selectivity of polycarbonate units was 87%. GPC test showed that the molecular weight of the obtained polymer was 17.4 kDa.

[0091] Example 12

[0092] 1.80g of styrene oxide, 0.0141g of the trinuclear cobalt compound obtained in Example 6 and 0.0174g of bistriphenylphosphine ammonium chloride were sequentially added into a high-pressure reactor that had been dehydrated and deoxygenated at high temperature, and 2MPa of carbon dioxide gas was introduced into the reactor. The reactor was placed in a 30°C oil bath and heated and stirred for 3h, then cooled and a small amount of the reaction solution was dissolved in CDCl3 for characterization of the monomer conversion rate; the remaining reaction solution was dropped into methanol to purify the polymer product.

[0093] The present invention conducts the obtained reaction product 1 H-NMR analysis showed that the conversion rate of styrene oxide was 79% and the selectivity of polycarbonate units was 68%. GPC test showed that the molecular weight of the obtained polymer was 10.5 kDa.

[0094] Embodiment 13

[0095] 3.0 g of styrene oxide, 0.444 g of phthalic anhydride, 0.0178 g of the trinuclear cobalt compound obtained in Example 5 and 0.0174 g of bistriphenylphosphine ammonium chloride were added in sequence into a high-pressure reactor that had been dehydrated and deoxygenated at high temperature, and 2 MPa of carbon dioxide gas was introduced therein. The reactor was placed in a 30°C oil bath and heated with stirring for 8 hours. The reactor was then cooled and a small amount of the reaction liquid was dissolved in CDCl3 for characterization of the monomer conversion rate; the remaining reaction liquid was dropped into methanol to purify the polymer product.

[0096] The present invention conducts the obtained reaction product 1 H-NMR analysis, the results are as follows Figure 2 As shown, Figure 2 This is the nuclear magnetic resonance hydrogen spectrum of the oxidized styrene-based biodegradable polymer material obtained in Example 13. The results show that the phthalic anhydride is completely reacted, the conversion rate of oxidized styrene is 63%, and the selectivity of the polycarbonate unit is 81%; the GPC test characterizes that the molecular weight of the obtained polymer is 24.8 kDa.

[0097] Embodiment 14

[0098] 2.40 g of styrene oxide, 0.328 g of nadic anhydride, 0.0141 g of the trinuclear cobalt compound obtained in Example 6 and 0.0174 g of bistriphenylphosphine ammonium chloride were added in sequence into a high-pressure reactor that had been dehydrated and deoxygenated at high temperature, and 3 MPa of carbon dioxide gas was introduced therein. The reactor was placed in an oil bath at 25°C and heated with stirring for 10 hours. The reactor was then cooled and a small amount of the reaction liquid was dissolved in CDCl3 for characterization of the monomer conversion rate; the remaining reaction liquid was dropped into methanol to purify the polymer product.

[0099] The present invention conducts the obtained reaction product 1 H-NMR analysis showed that the nadic anhydride was completely reacted, the conversion rate of styrene oxide was 68%, and the selectivity of polycarbonate units was 64%. GPC test characterized the molecular weight of the obtained polymer to be 12.7 kDa.

[0100] Embodiment 15

[0101] 1.80 g of styrene oxide, 0.296 g of phthalic anhydride, 0.0178 g of the trinuclear cobalt compound obtained in Example 5 and 0.0115 g of bistriphenylphosphine ammonium chloride were added in sequence into a high-pressure reactor that had been dehydrated and deoxygenated at high temperature, and 1 MPa of carbon dioxide gas was introduced therein. The reactor was placed in a 25°C oil bath and heated with stirring for 10 hours. The reactor was then cooled and a small amount of the reaction liquid was dissolved in CDCl3 for characterization of the monomer conversion rate; the remaining reaction liquid was dropped into methanol to purify the polymer product.

[0102] The present invention conducts the obtained reaction product 1H-NMR analysis showed that phthalic anhydride was completely reacted, the conversion rate of styrene oxide was 72%, and the selectivity of polycarbonate units was 90%; GPC test characterized the molecular weight of the obtained polymer to be 16.8 kDa.

[0103] Example 16

[0104] 1.20 g of styrene oxide, 0.148 g of phthalic anhydride, 0.0163 g of the trinuclear cobalt compound obtained in Example 7 and 0.0174 g of bistriphenylphosphine ammonium chloride were added in sequence into a high-pressure reactor that had been dehydrated and deoxygenated at high temperature, and 3 MPa of carbon dioxide gas was introduced therein. The reactor was placed in a 30°C oil bath and heated with stirring for 6 hours. The reactor was then cooled and a small amount of the reaction liquid was dissolved in CDCl3 for characterization of the monomer conversion rate; the remaining reaction liquid was dropped into methanol to purify the polymer product.

[0105] The present invention conducts the obtained reaction product 1 H-NMR analysis showed that phthalic anhydride was completely reacted, the conversion rate of styrene oxide was 81%, and the selectivity of polycarbonate units was 90%; GPC test characterized the molecular weight of the obtained polymer to be 9.4 kDa.

[0106] Embodiment 17

[0107] 1.80 g of styrene oxide, 0.148 g of phthalic anhydride, 0.0326 g of the trinuclear cobalt compound obtained in Example 7 and 0.0261 g of bistriphenylphosphine ammonium chloride were added in sequence into a high-pressure reactor that had been dehydrated and deoxygenated at high temperature, and 3 MPa of carbon dioxide gas was introduced therein. The reactor was placed in a 40°C oil bath and heated with stirring for 6 hours, then the reactor was cooled and a small amount of the reaction liquid was dissolved in CDCl3 for characterization of the monomer conversion rate; the remaining reaction liquid was dropped into methanol to purify the polymer product.

[0108] The present invention conducts the obtained reaction product 1 H-NMR analysis showed that phthalic anhydride was completely reacted, the conversion rate of styrene oxide was 71%, and the selectivity of polycarbonate units was 64%. GPC test characterized the molecular weight of the obtained polymer to be 7.6 kDa.

[0109] Embodiment 18

[0110] 2.40 g of styrene oxide, 0.888 g of phthalic anhydride, 0.0178 g of the trinuclear cobalt compound obtained in Example 5 and 0.0261 g of bistriphenylphosphine ammonium chloride were added in sequence into a high-pressure reactor that had been dehydrated and deoxygenated at high temperature, and 3 MPa of carbon dioxide gas was introduced therein. The reactor was placed in a 30°C oil bath and heated with stirring for 5 hours. The reactor was then cooled and a small amount of the reaction liquid was dissolved in CDCl3 for characterization of the monomer conversion rate; the remaining reaction liquid was dropped into methanol to purify the polymer product.

[0111] The present invention conducts the obtained reaction product 1 H-NMR analysis showed that phthalic anhydride was completely reacted, the conversion rate of styrene oxide was 62%, and the selectivity of polycarbonate units was 78%. GPC test characterized the molecular weight of the obtained polymer to be 11.5 kDa.

[0112] As can be seen from the above examples, under the catalytic action of the trinuclear cobalt compound with a triazine ring as a connecting group and an organic base co-catalyst of the structure shown in formula (IV), either a cyclic anhydride or carbon dioxide can be subjected to a binary copolymerization reaction with an epoxide with an electron-withdrawing group, and both a cyclic anhydride and carbon dioxide can be subjected to a ternary copolymerization reaction with an epoxide with an electron-withdrawing group. The examples show that the conversion rate of the cyclic anhydride in the polymerization reaction reaches 100%, and the conversion rate of styrene oxide is above 60%, and a degradable multi-polymer with diverse structures and regular sequences is obtained, and its molecular weight reaches 24.8 kDa.

[0113] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A trinuclear cobalt compound having the structure of formula (IV): Said R1 and R2 are independently selected from hydrogen or tert-butyl; The X is selected from acetate or 2,4-dinitrophenoloxy.

2. A method for preparing an electron-withdrawing multi-polyester material, comprising: Under the action of a catalyst and an organic base, at least one of a cyclic acid anhydride and carbon dioxide of the structure represented by formula (III) is reacted with an epoxide of the structure represented by formula (2) to obtain an electron-withdrawing multi-polyester material of the structure represented by formula (1); The catalyst is the trinuclear cobalt compound of claim 1; The Q is selected from The 0≤m≤200; 0≤n≤300; the m and n are not 0 at the same time; The R is selected from substituted or unsubstituted C1 to C 20 Alkyl, substituted or unsubstituted C6~C 30 Aryl, substituted or unsubstituted C2~C 30 Heteroaryl, substituted or unsubstituted C1~C 20 Alkoxy, substituted or unsubstituted C6~C 20 aryloxy, substituted or unsubstituted C3~C 40 Siloxy, substituted or unsubstituted C1~C 20 Acyl, substituted or unsubstituted C2~C 20 Alkoxycarbonyl, substituted or unsubstituted C2~C 20 substituted or unsubstituted C2~C 20 Amide group, substituted or unsubstituted C2~C 20 Alkoxycarbonylamino, substituted or unsubstituted C7~C 20 aryloxycarbonylamino, substituted or unsubstituted C1~C 20 Sulfonamido, substituted or unsubstituted C1~C 20 Sulfonyl, substituted or unsubstituted C1~C 20 Alkylthio, substituted or unsubstituted C6~C 20 arylthio, substituted or unsubstituted C1~C 20 Heterocyclic thio, substituted or unsubstituted C1~C 20 ureide group, substituted or unsubstituted C3~C 40 of silyl, hydrogen, halogen, cyano or nitro.

3. The preparation method according to claim 2, characterized in that: The specific structure of the electron-withdrawing multi-polyester material is shown in formula (I):

4. The preparation method according to claim 2, characterized in that: The organic base is selected from one or more of bis(triphenylphosphorane)ammonium chloride, 4-dimethylaminopyridine, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, N-methylimidazole, tricyclohexylphosphine, tetrabutylammonium chloride and tetrabutylammonium bromide.

5. The preparation method according to claim 2, characterized in that: The molar ratio of the catalyst to the organic base is 1:1-6.

6. The preparation method according to claim 2, characterized in that: The molar ratio of the total mole number of the catalyst and the organic base to the cyclic acid anhydride and the epoxide is 1:100-1000:500-10000.

7. The preparation method according to claim 2, characterized in that: The pressure of the carbon dioxide is 0.1-5 MPa; The reaction temperature is 25 to 120° C.; the reaction time is 0.5 to 120 h.

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