A water-soluble polycarbonate material and a synthesis method thereof

Abstract

The present invention discloses a water-soluble polycarbonate material and a synthesis method. Using polycarbonate prepared by the alternating copolymerization of alkylene oxide and carbon dioxide as the raw material, the carboxyl protecting group on the side chain is removed, a carboxyl functional group is introduced, and a polymer containing a carboxylate functional group is further prepared. The entire synthesis route has high atom economy, is simple to operate, the reaction conditions are relatively mild, and the prepared polycarbonate has excellent biodegradability. Due to the presence of hydrophilic groups in the polymer molecular chain, the hydrophilicity is significantly improved, and it also has a certain solubility in water. As a water-soluble polycarbonate material, it can be prepared into stable nanoparticles with high uniformity, and these nanoparticles can be applied in aspects such as drug carriers, cancer treatment, gene diagnosis, antibacterial materials, etc.

Description

Technical Field

[0001] The present invention relates to a water-soluble polycarbonate material and a synthesis method. Using a polycarbonate prepared by alternating copolymerization of an alkylene oxide and carbon dioxide as a raw material, the carboxyl protecting group on the side chain is removed, a carboxyl functional group is introduced, and a polycarbonate containing a carboxylate functional group is further prepared. Due to the presence of hydrophilic groups (carboxyl group, carboxylate group) in the polymer molecular chain, the hydrophilicity is significantly improved, and it has a certain solubility in water. As a water-soluble polycarbonate material, it can be prepared into stable nanoparticles with high uniformity, and these nanoparticles can be applied in aspects such as drug carriers, cancer treatment, gene diagnosis, antibacterial materials, etc. Background Art

[0002] Due to their excellent acid and alkali resistance, film-forming property, ductility, chemical stability, corrosion resistance, insulation property, light weight, easy coloring and other characteristics, polymer materials are widely used in many aspects such as household appliances, automobiles, furniture, packaging products, agricultural films, etc. At present, polymer materials have become an indispensable part of modern social life. However, the raw materials required for the production of most polymer materials come from non-renewable fossil energy such as petroleum, coal, and natural gas, and waste polymer materials are difficult to degrade under natural conditions, causing white pollution. The CO2-based polycarbonate using abundant, non-toxic, inexpensive, and renewable CO2 as a raw material not only realizes the high-value utilization of CO2, but also can alleviate the current plastic pollution problem and the high dependence of traditional plastics on fossil resources. As an environmentally friendly polymer material, the entire life cycle of the synthesis, use, and degradation of CO2-based polycarbonate implements the concept of green chemistry.

[0003] At present, common polycarbonates include poly(propylene carbonate) (PPC) and poly(cyclohexene carbonate) (PCHC). Among them, PPC was the first to achieve industrial mass production and practical application. However, it is an amorphous polymer material with poor thermodynamic and mechanical properties (Journal of Applied Polymer Science, 2002, 85, 2327 - 2334). Due to the insertion of rigid cyclohexyl groups into the main chain of PCHC, it has a relatively high glass transition temperature (about 120 °C), which helps to improve the poor heat resistance of PPC (Polymer, 2001, 42, 3995 - 4004). However, these common polycarbonates mainly focus on the mechanical properties, processing properties, and thermodynamic properties of the materials themselves. This indirectly leads to their mostly inert chemical structures and lack of functionality, making it difficult for them to be used as high - value - added functional materials (Adv. Funct. Mater., 2018, 28, 1704302). In order to improve the "inert properties" of polycarbonates themselves, the present invention introduces hydrophilic groups (carboxyl groups, carboxylate groups) into the polymer chain to prepare water - soluble polycarbonate materials. And this material can form stable nanoparticles, expanding the application scope of polycarbonates to fields such as biomedicine, functional coatings, and antibacterial materials. Summary of the Invention

[0004] The first object of the present invention is to provide a water - soluble polycarbonate material.

[0005] The second object of the present invention is to provide a synthesis method of a water - soluble polycarbonate material.

[0006] To achieve the above objects, the technical solutions adopted by the present invention are as follows:

[0007] A water - soluble polycarbonate material has the following structural formula:

[0008]

[0009] In the formula, M is a lithium atom, a sodium atom, a potassium atom, NH4, N(CH3)4, or N(CH2CH3)4.

[0010] A synthesis method of a water - soluble polycarbonate material uses a polycarbonate prepared by the alternating copolymerization of an alkylene oxide and CO2 as a raw material. The carboxyl protecting groups on the side chain are removed through a catalytic hydrogenolysis reaction to obtain a carboxyl - containing polycarbonate, and further a carboxylate - containing polycarbonate is prepared through a metathesis reaction. The specific steps are as follows:

[0011] The synthesis route of the water - soluble polycarbonate material is as follows:

[0012]

[0013] In the formula, R1 is CH3, CH2CH3, CH2CH2CH3, CH(CH3)2, CH2CH2CH2CH3, CHCH3CH2CH3, CH2CH(CH3)2, C(CH3)3, (CH2)4CH3, C(CH3)2CH2CH3, CHCH3CH2CH2CH3, CCH3(CH2CH3)CH3, CH2CHCH3CH2CH3, CH2C(CH3)3, CH2CH2CH(CH3)2, CH(CH2CH3)2, (CH2)5CH3, CH2C6H5, CH(C6H5)2, C(C6H5)3; R2 is OH, OCH3, OCH2CH3, OC(CH3)3; X is a bromine atom, a chlorine atom, or an iodine atom.

[0014] (1) Synthesis of the monomer: Dissolve 3-cyclopentene carboxylic acid in N,N-dimethylformamide, control the concentration of 3-cyclopentene carboxylic acid to be 0.1 - 2 mol / L, then add a halogenated hydrocarbon and potassium carbonate, where the molar ratio of 3-cyclopentene carboxylic acid, the halogenated hydrocarbon, and potassium carbonate is 5:(5 - 7):(10 - 12), react at room temperature for 1 - 48 hours to obtain Compound 2; then after purifying Compound 2 by column chromatography, dissolve it in dichloromethane, control the concentration of Compound 2 to be 0.05 - 1 mol / L, add meta-chloroperoxybenzoic acid under ice bath conditions, where the molar ratio of Compound 2 to meta-chloroperoxybenzoic acid is 5:(6 - 8), after the reaction stabilizes, remove the ice bath and continue the reaction at room temperature for 1 - 48 hours, and obtain Compound 3 after purification by column chromatography;

[0015] (2) Transfer the purified Compound 3 to a pressure-resistant reactor, add a main catalyst and a co-catalyst, where the molar ratio of the catalyst, the co-catalyst, and the alkylene oxide monomer in Compound 3 is 1:(1 - 50):(200 - 200000), carry out a ring-opening polymerization reaction of alkylene oxide and CO2 in an atmosphere of carbon dioxide to obtain Polymer 4; then after purifying Polymer 4 by precipitation method, dissolve it in an organic solution, transfer it to a pressure-resistant reactor, add palladium on carbon, where the mass ratio of palladium on carbon to Polymer 4 is 1:2 - 1:100, carry out a catalytic hydrogenolysis reaction in an atmosphere of hydrogen to obtain Polymer 5; then after purifying Polymer 5 by precipitation method, dissolve it in an organic solution, and carry out a metathesis reaction with a base, where the molar ratio of the base to Polymer 5 is 0.1 - 3, and obtain Polymer 6 by centrifugation.

[0016] The bases used in the said metathesis reaction include lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonium hydroxide, lithium tert-butoxide, sodium methoxide, sodium ethoxide, sodium tert-butoxide, potassium methoxide, potassium ethoxide, potassium tert-butoxide, tetramethylammonium hydroxide, and tetraethylammonium hydroxide.

[0017] The organic solvents used in the catalytic hydrogenolysis reaction include one or more mixtures of acetone, ethyl acetate, tetrahydrofuran, dichloromethane, methanol, ethanol, acetonitrile, isopropanol, chloroform, and dioxane.

[0018] The organic solvents used in the metathesis reaction include one or more mixtures of acetone, ethyl acetate, tetrahydrofuran, dichloromethane, methanol, ethanol, acetonitrile, isopropanol, chloroform, dioxane, and N,N-dimethylformamide.

[0019] The concentration of polymer 4 in the organic solvent in the catalytic hydrogenolysis reaction is 0.001 mol / L to 10 mol / L.

[0020] The concentration of polymer 5 in the organic solvent in the metathesis reaction is 0.001 mol / L to 10 mol / L.

[0021] The conditions for the ring-opening polymerization reaction are: reaction temperature is 0 to 100 °C, carbon dioxide pressure is 0.1 to 6.0 MPa, and reaction time is 1 to 480 hours.

[0022] The conditions for the catalytic hydrogenolysis reaction are: reaction temperature is 25 to 70 °C, hydrogen pressure is 0.1 to 6.0 MPa, and reaction time is 1 to 120 hours.

[0023] The conditions for the metathesis reaction are: reaction temperature is 25 to 70 °C, and reaction time is 0.1 to 24 hours.

[0024] The structure of the main catalyst in the ring-opening polymerization reaction is:

[0025]

[0026] In the formula, DNP is 2,4-dinitrophenol oxy.

[0027] The co-catalyst in the ring-opening polymerization reaction is bis-(triphenylphosphonium)(2,4-dinitrophenolate) ammonium.

[0028] The beneficial effects of the present invention:

[0029] (1) One of the raw materials for the polymerization reaction is CO2, which is abundant, non-toxic, cheap, and renewable;

[0030] (2) The CO2 polycarbonate material has excellent biodegradability;

[0031] (3) The synthesis route has high atomic economy, simple operation, and relatively mild reaction conditions;

[0032] (4) The catalyst has high activity, and the selectivity of the polymerization product is higher than 99%;

[0033] (5) The alternating structure in the polycarbonate product is higher than 99%, and the molecular weight distribution is relatively narrow;

[0034] (6) The hydrophilicity of the prepared water-soluble polycarbonate material is significantly improved compared with that of ordinary polycarbonate materials;

[0035] (7) The water-soluble polycarbonate material can be used to prepare nanoparticles with high uniformity. Description of the Drawings

[0036] Figure 1 1H NMR spectrum of polycarbonate containing benzyl protecting group;

[0037] Figure 2 13C NMR spectrum of polycarbonate containing benzyl protecting group;

[0038] Figure 3 1H NMR spectrum of polycarbonate containing carboxyl group;

[0039] Figure 4 13C NMR spectrum of polycarbonate containing carboxyl group;

[0040] Figure 5 Dynamic light scattering spectrum of polymer nanoparticles containing carboxyl group;

[0041] Figure 6 Dynamic light scattering spectrum of polymer nanoparticles containing ammonium carboxylate. Detailed Embodiments

[0042] The following further illustrates the detailed embodiments of the present invention in combination with the drawings and technical solutions.

[0043] Example 1:

[0044] Preparation of Monomer:

[0045] Under the protection of nitrogen, 3-cyclopentene carboxylic acid was dissolved in N,N-dimethylformamide, and the concentration of 3-cyclopentene carboxylic acid was controlled to be 1 mol / L. Subsequently, benzyl bromide and potassium carbonate were added, and the molar ratio of 3-cyclopentene carboxylic acid, benzyl bromide and potassium carbonate was 5:6:10. The reaction was carried out at room temperature for 12 hours. Water with the same volume as N,N-dimethylformamide was added to the reaction solution, and the mixture was extracted with ethyl acetate. The organic phase was separated, washed with saturated brine, dried over anhydrous sodium sulfate after separation, and concentrated, and then separated by column chromatography to obtain a colorless liquid as the product;

[0046] Under nitrogen protection, benzyl 3-cyclopentene carboxylate was dissolved in dichloromethane, and the concentration of benzyl 3-cyclopentene carboxylate was controlled to be 0.25 mol / L. It was cooled to 0 °C in an ice bath, and then m-chloroperbenzoic acid was slowly added. The molar ratio of benzyl 3-cyclopentene carboxylate to m-chloroperbenzoic acid was 5:7. After the reaction stabilized, the ice bath was removed, and the reaction was carried out at room temperature for 24 hours. Then, saturated sodium thiosulfate solution was added to make the reaction solution neutral. It was stirred for 1 hour, the organic phase was separated, washed with saturated sodium bicarbonate solution, dried with anhydrous sodium sulfate after separating the organic phase, and separated by column chromatography after concentration to obtain the product as a colorless liquid.

[0047] Example 2:

[0048] The implementation method of the polymerization-related reaction is shown in Table 1 for details:

[0049] In a 100 mL stainless steel autoclave, the following were added in sequence at ambient temperature: a certain amount of main catalyst, cocatalyst, 20 mL of alkylene oxide, carbon dioxide gas was introduced, and the temperature was quickly raised to the set temperature. The carbon dioxide pressure of the reaction system was kept constant through a regulating valve. After keeping the autoclave at an appropriate temperature and pressure for a specified reaction time, stirring was stopped, and the unreacted carbon dioxide was slowly released. The polymerization product was precipitated and washed three times with chloroform / methanol and dried to a constant weight under vacuum. Gel permeation chromatography was used to determine the polymer molecular weight and its distribution; Varian INOVA-400MHz was used to determine its 1 HNMR, and the carbonate unit content of the polymerization product was calculated.

[0050] Table 1 Copolymerization of alkylene oxide and carbon dioxide catalyzed by trivalent cobalt

[0051]

[0052]

[0053]

[0054] Note 1: All catalytic reactions are bulk polymerization

[0055] Note 2: The structure of the catalyst is:

[0056]

[0057] In the formula, DNP is the 2,4-dinitrophenol oxyanion.

[0058] Note 3: The cocatalyst is bis-(triphenylphosphonium)(2,4-dinitrophenolate)ammonium.

[0059] Example 3:

[0060] The implementation method of the catalytic hydrogenolysis-related reaction is shown in Table 2:

[0061] Weigh the protected polycarbonate and transfer it to a 100 mL stainless steel autoclave. Add a certain amount of solvent to dissolve the polymer. After the polymer is completely dissolved, add palladium-carbon and fill the autoclave with hydrogen. After maintaining the autoclave at an appropriate temperature, pressure, and specified reaction time, stop stirring and slowly release the unreacted hydrogen. The product is precipitated and washed three times with acetone / dichloromethane and dried to a constant weight under vacuum. The molecular weight and its distribution of the polymer are determined by gel permeation chromatography; its 1 HNMR is measured using a Varian INOVA-400MHz, and the conversion rate of the hydrogenation reduction reaction is calculated.

[0062] Table 2 Hydrogenation reduction reaction of polycarbonate

[0063]

[0064]

[0065] Example 4:

[0066] For the metathesis reaction, under nitrogen protection, dissolve the polycarbonate containing carboxyl groups in acetone, and slowly add aqueous ammonium hydroxide solution dropwise through a syringe, controlling the molar ratio of the polycarbonate containing carboxyl groups to ammonium hydroxide to be 1:0.9. Stir at room temperature for 10 minutes to produce a white precipitate. The product is obtained by centrifugation and dried to a constant weight under vacuum.

[0067] Example 5:

[0068] Preparation of polymer nanoparticles containing carboxyl groups. In a 20 mL serum bottle, dissolve the polymer containing carboxyl groups in acetone to prepare a polymer solution with a concentration of 0.63 mmol / L, and take 0.5 mL and disperse it into 10 mL of ultrapure water under ultrasonic conditions to obtain a polymer nanoparticle dispersion. The particle size of the polymer nanoparticles is measured to be about 99 nm by dynamic light scattering, as Figure 5 shown.

[0069] Example 6:

[0070] Preparation of polymer nanoparticles containing ammonium carboxylate. Add the polymer containing ammonium carboxylate to ultrapure water under ultrasonic conditions, where the concentration of the polymer solution is 1 mg / mL, to obtain a polymer nanoparticle dispersion. The particle size of the polymer nanoparticles is measured to be about 368 nm by dynamic light scattering, as Figure 6 shown.

Claims

1. A water-soluble polycarbonate material, characterized in that, The structural formula of the polycarbonate material is as follows: In the formula, M is a lithium atom, a sodium atom, a potassium atom, NH4, N(CH3)4, or N(CH2CH3)4.

2. A method for synthesizing a water-soluble polycarbonate material, characterized in that, Using the polycarbonate prepared by the alternating copolymerization of an alkylene oxide and CO2 as a raw material, the carboxyl protecting group on the side chain is removed through a catalytic hydrogenolysis reaction to obtain a carboxyl-containing polycarbonate, and further a polycarbonate containing carboxylate is prepared through a metathesis reaction; The specific steps are as follows: The synthesis route of the water-soluble polycarbonate material is as follows: In the formula, R1 is CH3, CH2CH3, CH2CH2CH3, CH(CH3)2, CH2CH2CH2CH3, CHCH3CH2CH3, CH2CH(CH3)2, C(CH3)3, (CH2)4CH3, C(CH3)2CH2CH3, CHCH3CH2CH2CH3, CCH3(CH2CH3)CH3, CH2CHCH3CH2CH3, CH2C(CH3)3, CH2CH2CH(CH3)2, CH(CH2CH3)2, (CH2)5CH3, CH2C6H5, CH(C6H5)2, C(C6H5)3; R2 is OH, OCH3, OCH2CH3, OC(CH3)3; X is a bromine atom, a chlorine atom, or an iodine atom; M is a lithium atom, a sodium atom, a potassium atom, NH4, N(CH3)4, or N(CH2CH3)4; (1) Synthesis of the monomer: Dissolve 3-cyclopentene carboxylic acid in N,N-dimethylformamide, control the concentration of 3-cyclopentene carboxylic acid to be 0.1 - 2 mol / L, and then add a halogenated hydrocarbon and potassium carbonate. The molar ratio of 3-cyclopentene carboxylic acid, the halogenated hydrocarbon, and potassium carbonate is 5:(5 - 7):(10 - 12), and react at room temperature for 1 - 48 hours to obtain compound 2; then after purifying compound 2 by column chromatography, dissolve it in dichloromethane, control the concentration of compound 2 to be 0.05 - 1 mol / L, add m-chloroperbenzoic acid under ice bath conditions. The molar ratio of compound 2 to m-chloroperbenzoic acid is 5:(6 - 8). After the reaction is stable, remove the ice bath and continue to react at room temperature for 1 - 48 hours, and obtain compound 3 after purification by column chromatography; (2) Transfer the purified compound 3 to a pressure-resistant autoclave, add a main catalyst and a co-catalyst. The molar ratio of the main catalyst, the co-catalyst, and the alkylene oxide monomer in compound 3 is 1:(1 - 50):(200 - 200000), and carry out a ring-opening polymerization reaction of the alkylene oxide and CO2 in an atmosphere of carbon dioxide to obtain polymer 4; then after purifying polymer 4 by precipitation method, dissolve it in an organic solution, transfer it to a pressure-resistant autoclave, add palladium on carbon. The mass ratio of palladium on carbon to polymer 4 is 1:2 - 1:100, and carry out a catalytic hydrogenolysis reaction in an atmosphere of hydrogen to obtain polymer 5; then after purifying polymer 5 by precipitation method, dissolve it in an organic solution, and carry out a metathesis reaction with a base. The molar ratio of the base to polymer 5 is 0.1 - 3, and polymer 6 is obtained by centrifugation.

3. The synthesis method according to claim 2, characterized in that, The bases used in the metathesis reaction include lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonium hydroxide, lithium tert-butoxide, sodium methoxide, sodium ethoxide, sodium tert-butoxide, potassium methoxide, potassium ethoxide, potassium tert-butoxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide; the organic solvents used in the metathesis reaction include one or more mixtures of acetone, ethyl acetate, tetrahydrofuran, dichloromethane, methanol, ethanol, acetonitrile, isopropanol, chloroform, dioxane, N,N-dimethylformamide; the concentration of polymer 5 in the organic solvent in the metathesis reaction is 0.001 mol / L to 10 mol / L; the conditions of the metathesis reaction are: the reaction temperature is 25 to 70 °C, and the reaction time is 0.1 to 24 hours.

4. The synthesis method according to claim 2, characterized in that The organic solvents used in the catalytic hydrogenolysis reaction include one or more mixtures of acetone, ethyl acetate, tetrahydrofuran, dichloromethane, methanol, ethanol, acetonitrile, isopropanol, chloroform, dioxane; the concentration of polymer 4 in the organic solvent in the catalytic hydrogenolysis reaction is 0.001 mol / L to 10 mol / L; the conditions of the catalytic hydrogenolysis reaction are: the reaction temperature is 25 to 70 °C, the hydrogen pressure is 0.1 to 6.0 MPa, and the reaction time is 1 to 120 hours.

5. The synthesis method according to claim 2, characterized in that, The conditions of the ring-opening polymerization reaction are: The reaction temperature is 0 to 100 °C, the carbon dioxide pressure is 0.1 to 6.0 MPa, and the reaction time is 1 to 480 hours.

6. The synthesis method according to claim 2, wherein The structure of the main catalyst in the ring-opening polymerization reaction is: In the formula, DNP is 2,4-dinitrophenol oxygen.

7. The synthesis method according to claim 2, wherein The cocatalyst in the ring-opening polymerization reaction is bis-(triphenylphosphonium)(2,4-dinitrophenolate)ammonium.

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