Catalyst for addition reaction of alkylene oxide and its application
阅读说明：本技术 环氧烷烃加成反应催化剂及其应用 (Catalyst for addition reaction of alkylene oxide and its application ) 是由 俞峰萍 何文军 金铭 于 2019-09-24 设计创作，主要内容包括：本发明涉及一种用于环氧烷烃加成反应的催化剂,所述催化剂包括结构式为P-Im-M-的纳米复合离子交换树脂,其中P为纳米复合树脂基体,Im为咪唑阳离子,M-为阴离子,本发明的催化剂用于环氧烷烃与二氧化碳的加成反应中,催化剂耐热性、耐溶胀性高,且活性高,反应后产物易分离,催化剂可连续使用多次。(The invention relates to a catalyst for addition reaction of alkylene oxide, which comprises a nano composite ion exchange resin with a structural formula of P-Im-M-, wherein P is a nano composite resin matrix, Im is imidazole cation, and M-is anion.)
1. A catalyst for addition reaction of alkylene oxide contains P-Im-M-Wherein P is the nanocomposite ion exchange resinA matrix, Im is an imidazolium cation, M-Is an anion.
2. The catalyst of claim 1 wherein the nanocomposite resin matrix comprises structural segments of formula I and-CH (poss) -CH2-a structural fragment of a protein,
in the formula I, R1-R8Are the same or different and are each independently selected from hydrogen and C1-C6Alkyl, preferably selected from hydrogen, methyl, ethyl, propyl and butyl;
POSS is cage type silsesquioxane with the general formula of (-SiO)1.5) m, m is 6, 8, 10 or 12.
3. The catalyst of claim 1 or 2, wherein the catalyst comprises the structure:
wherein R is1-R3Are the same or different and are each independently selected from hydrogen and C1-C6An alkyl group;
R4-R8selected from hydrogen, C1-C6Alkyl and CH2Im+M-And R is4-R8At least one of them is CH2Im+M-Preferably, R4-R8Selected from hydrogen and CH2Im+M-And R is4-R8At least one of them is CH2Im+M。
4. The catalyst of any one of claims 1-3, wherein M is-Selected from the group consisting of halides andone or more of organic acid radical ions, preferably one or more selected from fluorine ion, chlorine ion, bromine ion, iodine ion, acetate, formate and hydrogen oxalate radical;
and/or the POSS mass content in the nano composite resin matrix P is 0.1-10%, preferably 0.2-5%, more preferably 2-5%.
5. A process for preparing a catalyst as claimed in any one of claims 1 to 4, comprising the steps of:
s1: polymerizing a styrene monomer, a cross-linking agent and cage type silsesquioxane in the presence of an initiator to obtain a nano composite resin matrix P;
s2: and (4) performing chloromethylation reaction, imidation reaction and ion exchange reaction on the nano composite resin matrix P obtained in the step S1.
6. The method of claim 5, wherein the styrenic monomers are selected from one or more of the styrenic monomers of formula II;
in the formula II, R1-R8Are the same or different and are each independently selected from hydrogen and C1-C6Alkyl, preferably selected from hydrogen, methyl, ethyl, propyl and butyl;
and/or the cage-type silsesquioxane is selected from one or more of vinyl-containing silsesquioxane, hydrogen-containing polysilsesquioxane, alkoxy-containing polysilsesquioxane and epoxy-containing polysilsesquioxane, preferably, the vinyl-containing silsesquioxane is selected from octavinyl silsesquioxane;
and/or the cross-linking agent is selected from one or more of ethylene glycol dimethacrylate, diacrylene, divinyl phenyl methane or divinyl benzene;
and/or the initiator is selected from at least one of benzoyl peroxide, azobisisobutyronitrile, azobisisoheptonitrile, lauroyl peroxide or cumene hydroperoxide,
and/or, in step S1, the mass of the styrene monomer is 85-95%, the mass of the cross-linking agent is 1-6%, the mass of the cage-type silsesquioxane is 0.1-10%, preferably 0.2-5%, more preferably 2-5%, and the mass of the initiator is 0.1-5%, based on the total weight of the raw materials.
7. A process for the addition reaction of an alkylene oxide to carbon dioxide comprising reacting an alkylene oxide and carbon dioxide in the presence of a catalyst according to any one of claims 1 to 4 or a catalyst prepared by a process according to claim 5 or 6.
8. The process according to any one of claim 7, wherein the alkylene oxide has the following general formula:
wherein R is9-R12The same or different, each is independently selected from hydrogen and C1-C6Alkyl and C6-C10Aryl, preferably selected from hydrogen, methyl, ethyl, propyl, butyl and phenyl; and/or the presence of a gas in the gas,
the mass ratio of the catalyst to the alkylene oxide is (0.001-1):1, preferably (0.1-0.3): 1.
9. The process according to claim 7 or 8, characterized in that the temperature of the reaction is 60-180 ℃, preferably 100-160 ℃; and/or the pressure of the reaction is 0.1-10.0MPa, preferably 2-5 MPa; and/or the reaction time is 1-8h, preferably 3-6 h.
10. Use of a catalyst according to any one of claims 1 to 4 or prepared by a process according to claim 5 or 6 in an alkylene oxide addition reaction.
Technical Field
The invention relates to an alkylene oxide addition reaction catalyst and application thereof, in particular to a nano composite ion exchange resin catalyst.
Background
Alkylene carbonates such as ethylene carbonate and propylene carbonate are excellent solvents and fine chemical intermediates, and have wide application. The ethylene carbonate is used as an excellent high-boiling point solvent and an organic synthesis intermediate, is widely used as a solvent in the aspects of spinning, printing, polymer synthesis and electrochemistry, and can also be used as a raw material of cosmetics and medicines and an intermediate of corresponding dihydric alcohol. In recent years, ethylene carbonate is applied to the production of lithium battery electrolyte and dimethyl carbonate, and the use of aliphatic polycarbonate and various copolymers thereof as degradable biological materials makes the industrial production and preparation thereof important.
The traditional production method of ethylene carbonate is a phosgene method, phosgene toxicity is high, pollution is serious, and the process has the defects of long flow, low yield, high cost and the like. The method is a new green and environment-friendly way for directly preparing the ethylene carbonate by taking the carbon dioxide and the ethylene oxide as raw materials under the action of corresponding catalysts, and the process can directly utilize the greenhouse gas of the carbon dioxide and relieve the problem of carbon dioxide emission.
Currently known homogeneous catalyst systems for addition reaction of carbon dioxide and epoxy compounds include quaternary ammonium salts, quaternary phosphonium salts, transition metal complexes, main group element complexes, alkali metal salts, ionic liquids, supercritical carbon dioxide and other catalyst systems.
He cheng et al developed a class of phosphonium salt catalysts, which synthesized ethylene carbonate in supercritical carbon dioxide using Rf3RPI (Rf R ═ C4F9C2H 4; Rf R ═ C6F13C2H 4; Rf ═ C6F13C2H4, R ═ Me; Rf ═ C8F17C2H4, R ═ Me;) as a catalyst, which contained longer fluorine chains and had better solubility for carbon dioxide, and less solubility in the product, facilitating product separation. The catalyst realizes in-situ regeneration and recycling of the catalyst in a supercritical state, and can be recycled, the yield of the ethylene carbonate reaches over 90 percent, but the reaction period is too long and needs 24 hours.
Kim et al investigated the effect of zinc halide with homogeneous catalytic systems such as 1-alkyl-3-methyl-imidazolium halides and phosphine-containing ligands on the reaction (Angew. chem. Int. Ed.39(2000) 4096-. After the reaction, the homogeneous catalyst needs to be separated from the product, which is separated from the homogeneous catalyst by distillation, which can severely decompose the alkylene carbonate.
The characteristics of the homogeneous catalysis system determine the defects of difficult product separation, large catalyst consumption, difficult recycling, environmental pollution and the like in the homogeneous process. Compared with a homogeneous catalyst, the heterogeneous catalyst is beneficial to the separation of subsequent products and the catalyst, and the catalyst is easy to regenerate and can be repeatedly used. As carriers of heterogeneous catalysis systems, molecular sieves, silica gel, ion exchange resins, polyethylene glycol, poly (4-vinylpyridine), chitosan and the like are commonly used.
Carried zinc halide catalysts are reported by Xiao et al in application.Catal.A 279(2005)125-129, the support being poly (4-vinylpyridine) or chitosan. The homogeneous phase 1-butyl-3-methylimidazolium bromide also needs to be used as a cocatalyst in the system, and the catalytic activity is obviously reduced after the homogeneous phase 1-butyl-3-methylimidazolium bromide is mechanically applied. Van Kruchten et al report in CN101511810A that zinc halide catalyst supported on solid carrier is quaternary phosphonium type or quaternary ammonium type ion exchange resin, and the activity of the catalyst system is reduced rapidly after the catalyst system is mechanically applied.
Lu soldiers et al studied a fixed-bed continuous process of ethylene carbonate using Salen (Co) supported on silica gel MCM-41 as a catalyst. Under the condition of adding n-butyl ammonium bromide as a co-catalyst, the conversion rate of the ethylene oxide can reach 85.6 percent.
Therefore, although the heterogeneous catalyst system has many advantages, it is still to be further improved in terms of the heat resistance, swelling resistance, and stability of catalytic active sites of the carrier, and it is very important to research and develop a catalyst system with high activity and easy separation.
Disclosure of Invention
In order to solve the problems in the prior art, the first aspect of the invention provides a catalyst for alkylene oxide addition reaction, the catalyst comprises a nano composite ion exchange resin with a structural formula of P-Im-M-, wherein P is a nano composite resin matrix, Im is imidazolium cation, and M-is anion.
In a second aspect of the invention, a process for the addition reaction of an alkylene oxide to carbon dioxide is provided.
According to a first aspect of the invention, the catalyst comprises a compound of formula P-Im-M-Wherein P is a nanocomposite resin matrix, Im is an imidazolium cation, and M is a salt of a quaternary ammonium compound-Is an anion of the anion-forming polymer,
according to some embodiments of the invention, the nanocomposite resin matrix comprises structural segments represented by formula I and-CH (POSS) -CH2-a structural fragment of a protein,
in the formula I, R1-R8Are the same or different and are each independently selected from hydrogen and C1-C6Alkyl, preferably selected from hydrogen, methyl, ethyl, propyl and butyl;
POSS is cage type silsesquioxane with the general formula of (-SiO)1.5) m, m is 6, 8, 10 or 12.
According to some embodiments of the invention, the catalyst comprises the structure:
wherein R is1-R3Are the same or different and are each independently selected from hydrogen and C1-C6An alkyl group;
R4-R8selected from hydrogen, C1-C6Alkyl and CH2Im+M-And R is4-R8At least one of them is CH2Im+M-Preferably, R4-R8Selected from hydrogen and CH2Im+M-And R is4-R8At least one of them is CH2Im+M。
According to some embodiments of the invention, the catalyst comprises a-CH- (Ph-CH2-Im + M) -CH 2-structural fragment.
According to some embodiments of the invention, the M "is selected from one or more of a halide ion and an organic acid ion.
According to some embodiments of the invention, the M "is selected from one or more of fluoride, chloride, bromide, iodide, acetate, formate and hydrogen oxalate.
According to some embodiments of the invention, the amount of POSS in the nanocomposite resin matrix P is 0.1-10% by mass, such as 0.1%, 0.2%, 0.5%, 1.0%, 1.2%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.3%, 4.5%, 5.0%, 5.5%, 6.0%, 7.0%, 8.0%, 9.1%, 9.5%, 10% and any value in between.
According to some embodiments of the invention, the POSS content of the nanocomposite resin matrix P is 0.2-5% by mass.
According to some embodiments of the present invention, the POSS content of the nanocomposite resin matrix P is 2-5% by mass.
In the present invention, the structural formula P-Im-M-Represent using Im and M-A modified nanocomposite resin matrix P.
According to some embodiments of the invention, the nanocomposite resin matrix P has an infrared spectrum of 1111cm-1The characteristic absorption peak is attributed to the stretching vibration absorption peak of the Si-O-Si framework in the silsesquioxane.
According to some embodiments of the invention, the preparation of the catalyst comprises the steps of:
s1: polymerizing a styrene monomer, a cross-linking agent and cage type silsesquioxane in the presence of an initiator to obtain a nano composite resin matrix P;
s2: and (4) performing chloromethylation reaction, imidation reaction and ion exchange reaction on the nano composite resin matrix P obtained in the step S1.
According to some embodiments of the invention, the nanocomposite resin matrix P is a nanocomposite copolymer obtained by in-situ copolymerization of a styrenic monomer, a crosslinking agent, and a nanomaterial.
According to some embodiments of the invention, the nanomaterial is selected from at least one of a vinyl-containing silsesquioxane, a hydrogen-containing polysilsesquioxane, an alkoxy-containing polysilsesquioxane and an epoxy-containing polysilsesquioxane.
According to some embodiments of the present invention, the styrenic monomer is selected from one or more of the styrenic monomers represented by formula II;
in the formula II R1-R8Are the same or different and are each independently selected from hydrogen and C1-C6Alkyl, preferably selected from hydrogen, methyl, ethyl, propyl and butyl.
According to some embodiments of the invention, the styrenic monomer is selected from at least one of styrene, alpha-methylstyrene or 4-butylstyrene, preferably styrene.
According to some embodiments of the invention, the cage-type silsesquioxane is selected from one or more of a vinyl-containing silsesquioxane, a hydrogen-containing polysilsesquioxane, an alkoxy-containing polysilsesquioxane and an epoxy-containing polysilsesquioxane.
According to some embodiments of the invention, the vinyl-containing silsesquioxane is selected from the group consisting of octavinyl silsesquioxane,
according to some embodiments of the invention, the cross-linking agent is selected from one or more of ethylene glycol dimethacrylate, diacrylene, divinylphenylmethane or divinylbenzene.
According to some embodiments of the invention, the initiator is selected from at least one of benzoyl peroxide, azobisisobutyronitrile, azobisheptanonitrile, lauroyl peroxide or cumene hydroperoxide.
According to some embodiments of the present invention, in step S1, the mass of the styrene monomer is 85 to 95% based on the total weight of the raw materials.
According to some embodiments of the invention, in step S1, the cross-linking agent is present in an amount of 1 to 6% by weight, based on the total weight of the starting materials.
According to some embodiments of the present invention, in step S1, the cage-type silsesquioxane has a mass of 0.1-10%, for example, 0.1%, 0.2%, 0.5%, 1.0%, 1.2%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.3%, 4.5%, 5.0%, 5.5%, 6.0%, 7.0%, 8.0%, 9.1%, 9.5%, 10% and any value therebetween, based on the total weight of the starting materials.
According to some embodiments of the present invention, in step S1, the cage-type silsesquioxane has a mass of 0.2-5% based on the total weight of the starting materials.
According to some embodiments of the present invention, in step S1, the cage-type silsesquioxane has a mass of 2-5% based on the total weight of the starting materials.
According to some embodiments of the invention, in step S1, the initiator is present in an amount of 0.1 to 5% by mass based on the total weight of the starting materials.
According to some embodiments of the present invention, the styrene monomer is used in an amount of 85 to 95 parts, the crosslinking agent is used in an amount of 2 to 5 parts, the nanomaterial is used in an amount of 0.1 to 10 parts, and the initiator is used in an amount of 0.1 to 5 parts by weight.
In some preferred embodiments of the present invention, the method for preparing the catalyst comprises the steps of:
a) preparing an auxiliary agent into a water solution A with the weight percentage concentration of 0.5-3%, and preparing a styrene monomer, a cross-linking agent, a nano material and an initiator into a solution B; wherein the auxiliary agent is selected from at least one of polyvinyl alcohol, gelatin, starch, methyl cellulose, bentonite or calcium carbonate; the styrene monomer is selected from at least one of styrene, alpha-methyl styrene or 4-butyl styrene; the crosslinking agent is selected from at least one of ethylene glycol dimethacrylate, diacrylene benzene, divinyl phenyl methane or divinyl benzene; the nano material is selected from at least one of vinyl-containing silsesquioxane, hydrogen-containing polysilsesquioxane, alkoxy-containing polysilsesquioxane and epoxy-containing polysilsesquioxane; the initiator is selected from at least one of benzoyl peroxide, azobisisobutyronitrile, azobisisoheptonitrile, lauroyl peroxide or cumene hydroperoxide; the weight portion of the styrene monomer is 85-95 parts, the cross-linking agent is 2-5 parts, the nano material is 0.1-10 parts, and the initiator is 0.1-5 parts; the dosage of the auxiliary agent is 150-400% of the dosage of the monomer;
b) and mixing the solution B and the solution A, stirring for 1-3 hours at normal temperature, and uniformly mixing. Then carrying out polymerization reaction at 60-75 ℃ for 0.5-5 hours, gradually heating to 70-90 ℃ for 5-15 hours, and then heating to 90-100 ℃ for 5-15 hours; after the reaction is finished, extracting, washing, filtering, drying and sieving to obtain composite microspheres with the particle size range of 0.35-0.60 mm;
c) adding a chloromethylation reagent which is 200-500% of the weight of the composite microsphere and a zinc chloride catalyst which is 20-70% of the weight of the composite microsphere into the composite microsphere, reacting for 8-30 hours at 30-60 ℃, filtering and washing to obtain a composite chlorine ball; the chloromethylation reagent is selected from at least one of chloromethyl ether, chloromethyl ethyl ether or 1, 4-dichloromethoxybutane;
d) reacting the mixture of the composite chlorine spheres and the N-methylimidazole at 60-90 ℃ for 10-48 hours, and filtering and washing after the reaction is finished to obtain composite imidazole microspheres; in the mixture, the mol ratio of the composite chlorine ball to the N-alkyl imidazole to the N, N-dimethylformamide is 1 (1-5) to 10-50;
f) washing the composite imidazole microspheres with a salt solution, wherein the molar ratio of the composite imidazole microspheres to the salt solution is (1:1) - (1: 10); the concentration of the salt solution is 0.1-1 mol/L; and after washing, washing the product by deionized water until the pH value is 7 to obtain the ion exchange resin. The salt solution is selected from at least one of fluoride ion, chloride ion, bromide ion, iodide ion, acetate, formate and oxalate hydrogen salt solution.
According to a second aspect of the present invention, the method for addition reaction of an alkylene oxide with carbon dioxide comprises reacting an alkylene oxide with carbon dioxide in the presence of the above-mentioned catalyst,
according to some embodiments of the invention, the alkylene oxide has the general formula:
wherein R is9-R12Are the same or different and are each independently selected from hydrogen and C1-C6Alkyl and C6-C10Aryl, preferably selected from hydrogen, methyl, ethyl, propyl, butyl and phenyl.
According to some embodiments of the invention, the alkylene oxide is selected from ethylene oxide, propylene oxide or styrene oxide.
According to some embodiments of the invention, the mass ratio of the catalyst to the alkylene oxide is (0.001-1):1, preferably (0.1-0.3): 1.
according to some embodiments of the invention, the temperature of the reaction is 60-180 ℃, such as 60 ℃, 70 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃, 160 ℃, 170 ℃, 1800 ℃ and any value in between.
According to some embodiments of the invention, the temperature of the reaction is 100-160 ℃.
According to some embodiments of the invention, the pressure of the reaction is 0.1-10.0MPa, such as 0.1MPa, 0.5MPa, 1MPa, 2MPa, 3MPa, 4MPa, 5MPa, 6MPa, 7MPa, 8MPa, 9MPa, 10MPa and any value in between.
According to some embodiments of the invention, the pressure of the reaction is 2 to 5 MPa.
According to some embodiments of the invention, the reaction time is 1 to 8 hours, preferably 3 to 6 hours.
The nano composite ion exchange resin catalyst is used in addition reaction of alkylene oxide and carbon dioxide, and has high heat resistance, high swelling resistance, high activity, easy separation of product after reaction and continuous use.
Drawings
FIG. 1: infrared spectrum of ion exchange resin in example 1.
Detailed Description
The invention is further illustrated by the following examples, but it is to be noted that the scope of the invention is not limited thereto, but is defined by the appended claims.
It should be particularly noted that two or more aspects (or embodiments) disclosed in the context of the present specification may be combined with each other at will, and thus form part of the original disclosure of the specification, and also fall within the scope of the present invention.
[ example 1 ] preparation of ion exchange resin
65.0 g of styrene, 1.0 g of divinylbenzene, 3.0 g of octavinyl silsesquioxane and 1.0 g of benzoyl peroxide are added into a 500ml three-neck flask, and a stirrer is started to stir for 0.5 hour; a mixed solution of 200ml of deionized water and 4 g of polyvinyl alcohol was added thereto, and stirred for 2 hours. Then gradually raising the temperature to 75 ℃ for reaction for 5 hours, then raising the temperature to 90 ℃ for reaction for 10 hours, and finally raising the temperature to 100 ℃ for reaction for 10 hours. After the reaction is finished, pouring out the upper layer liquid, washing with hot water at 85 ℃, washing with cold water, filtering, drying in an oven at 80 ℃, sieving, and collecting the composite microspheres A1 with the particle size of 0.35-0.60 mm.
Chloromethylation of the composite microsphere: adding 40 g of composite microspheres A1 and 250ml of chloromethyl ether into a 500ml three-neck flask, standing at room temperature for 3 hours, starting stirring, adding 10 g of zinc chloride as a catalyst, heating to 60 ℃ for reaction for 10 hours, cooling to room temperature after chloromethylation is finished, filtering out a chlorination mother solution, repeatedly washing with methanol, and drying at 100 ℃ for 8 hours to obtain the composite chlorine spheres A1.
Imidation: 30 g of composite chloro-sphere A1 (chlorine content is 3.4mmol Cl/g), 1-methylimidazole (102.0mmol) and 200ml of acetonitrile are added into a 500ml three-neck flask, the mixture reacts for 24 hours at 60 ℃, the temperature is cooled to room temperature, the mixture is filtered, the ethyl acetate, 0.1mol/L HCl, deionized water and methanol are sequentially used for washing, and then the mixture is dried for 12 hours at 60 ℃ in vacuum to obtain the composite imidazole microsphere A1.
Ion exchange: adding 30 g of composite imidazole microspheres A1 and 500ml of NaBr deionized water solution with the concentration of 0.1mol/L into a 1000ml three-neck flask, and stirring at room temperature to perform ion exchange reaction for 24 hours; subsequently, the solution was washed with deionized water until the pH of the washing solution became 7, and dried under vacuum to obtain an ion exchange resin catalyst, designated Cat-a1, having the following structural formula:
[ example 2 ] ion exchange resin preparation
A monomer mixture solution containing an initiator (60.0 g of styrene, 1.0 g of divinylbenzene, 1.6 g of octavinyl silsesquioxane and 1.0 g of benzoyl peroxide are added into a 500ml three-neck flask, the solution is stirred and reacted for 0.5 hour at 70 ℃, a stirrer is started, a mixed solution of 200ml of deionized water and 4 g of polyvinyl alcohol is added, the temperature is increased to 85 ℃, the reaction is carried out for 3 hours, the temperature is increased to 90 ℃, the reaction is carried out for 9 hours, and finally the temperature is increased to 100 ℃, and the reaction is carried out for 10 hours. After the reaction is finished, pouring out the upper layer liquid, washing with hot water at 85 ℃, washing with cold water, filtering, drying in an oven at 80 ℃, sieving, and collecting the composite microspheres B1 with the particle size of 0.35-0.60 mm.
Chloromethylation of the composite microspheres: adding 50 g of composite microsphere B1 and 200ml of chloroethyl ether into a 500ml three-neck flask, standing at room temperature for 6 hours, adding 30 g of zinc chloride serving as a catalyst, starting stirring, heating to 50 ℃ for reaction for 30 hours, cooling to room temperature after chloromethylation is finished, filtering out a chlorination mother solution, repeatedly washing with methanol, and drying at 100 ℃ for 8 hours to obtain the composite chlorine sphere B1.
Imidation: 50 g of composite chlorosphere B1 (the chlorine content is 4.6mmol Cl/g), 1-methylimidazole (230.0mmol) and 300ml of acetonitrile are added into a 500ml three-neck flask, the mixture reacts for 16 hours at 80 ℃, the mixture is cooled to room temperature and filtered, and the mixture is washed by ethyl acetate, 0.1mol/L HCl, deionized water and methanol in sequence and then dried for 12 hours at 60 ℃ in vacuum to obtain the composite imidazole microsphere B1.
Ion exchange: adding 40 g of composite imidazole microsphere B1 and 400ml of deionized water solution of NaBr with the concentration of 1.0mol/L into a 1000ml three-neck flask, and stirring at room temperature to perform an ion exchange reaction for 12 hours; subsequently, the solution was washed with deionized water until the pH of the washing solution became 7, and dried under vacuum to obtain an ion exchange resin catalyst, designated Cat-B1, having the following structural formula:
[ example 3 ] preparation of ion exchange resin
A monomer mixture solution containing an initiator (42.5 g of styrene, 2.5 g of divinylbenzene, 0.1 g of octavinyl silsesquioxane and 2.0 g of benzoyl peroxide, which is stirred at 70 ℃ for 1.5 hours) was charged into a 500ml three-neck flask, a mixed solution of 200ml of deionized water and 4 g of polyvinyl alcohol was added, the temperature was raised to 85 ℃ for reaction for 3 hours, then raised to 90 ℃ for reaction for 9 hours, and finally raised to 100 ℃ for reaction for 10 hours. After the reaction is finished, pouring out the upper layer liquid, washing with hot water at 85 ℃, washing with cold water, filtering, drying in an oven at 80 ℃, sieving, and collecting the composite microspheres C1 with the particle size of 0.35-0.60 mm.
Chloromethylation of the composite microspheres: adding 20 g of composite microsphere C1 and 100 ml of 1, 4-dichloromethoxybutane into a 250ml three-neck flask, standing for 6 hours at room temperature, adding 8 g of zinc chloride as a catalyst, starting stirring, heating to 30 ℃ for reaction for 12 hours, cooling to room temperature after chloromethylation is finished, filtering out chlorinated mother liquor, repeatedly washing with methanol, and drying for 8 hours at 100 ℃ to obtain the composite chlorine sphere C1.
Imidation: 20 g of composite chlorosphere C1 (with the chlorine content of 1.5mmol Cl/g), 1-ethylimidazole (30.0mmol) and 150ml of acetonitrile are added into a 250ml three-neck flask, the mixture reacts for 16 hours at the temperature of 90 ℃, the mixture is cooled to room temperature and filtered, and the mixture is washed by ethyl acetate, 0.1mol/L HCl, deionized water and methanol in sequence and then dried for 12 hours at the temperature of 60 ℃ in vacuum to obtain the composite imidazole microsphere C1.
Ion exchange: adding 20 g of composite imidazole microsphere C1 and 300ml of NaBr deionized water solution with the concentration of 0.5mol/L into a 500ml three-neck flask, and stirring at room temperature to perform an ion exchange reaction for 12 hours; followed by deionized water until the wash solution had a pH of 7 and dried under vacuum to give the ion exchange resin catalyst, designated Cat-C1, of the formula:
[ example 4 ] ion exchange resin preparation
47.0 g of styrene, 2.3 g of divinylbenzene and 1.6 g of benzoyl peroxide initiator are added into a 500ml three-neck flask, and stirred and reacted for 2.0 hours at the temperature of 60 ℃; then, 0.6 g of octavinyl silsesquioxane was added and stirring was continued for 1 hour to perform prepolymerization. A solution of 2.0 g of gelatin dissolved in 260 ml of deionized water was added. Adjusting the stirring speed, gradually raising the temperature to 80 ℃ at the same time, and reacting for 5 hours; then the temperature is raised to 90 ℃ for reaction for 5 hours, and finally the temperature is raised to 98 ℃ for reaction for 6 hours. After the reaction is finished, pouring out the upper layer liquid, washing with hot water at 85 ℃, washing with cold water, filtering, drying in an oven at 80 ℃, sieving, and collecting the composite microspheres A2 with the particle size of 0.35-0.60 mm.
Chloromethylation of the composite microsphere: adding 40 g of composite microspheres A2 and 250ml of chloromethyl ether into a 500ml three-neck flask, standing at room temperature for 3 hours, starting stirring, adding 10 g of zinc chloride as a catalyst, heating to 60 ℃ for reaction for 10 hours, cooling to room temperature after chloromethylation is finished, filtering out a chlorination mother solution, repeatedly washing with methanol, and drying at 100 ℃ for 8 hours to obtain the composite chlorine spheres A2.
Imidation: 30 g of composite chloro-sphere A2 (chlorine content is 3.6mmol Cl/g), 1-methylimidazole (108.0mmol) and 200ml of acetonitrile are added into a 500ml three-neck flask, the mixture reacts for 24 hours at 60 ℃, the temperature is cooled to room temperature, the mixture is filtered, the ethyl acetate, 0.1mol/L HCl, deionized water and methanol are sequentially used for washing, and then the mixture is dried for 12 hours at 60 ℃ in vacuum to obtain the composite imidazole microsphere A2.
Ion exchange: adding 30 g of composite imidazole microspheres A2 and 500ml of NaBr deionized water solution with the concentration of 0.1mol/L into a 1000ml three-neck flask, and stirring at room temperature to perform ion exchange reaction for 24 hours; subsequently, the solution was washed with deionized water until the pH of the washing solution became 7, and dried under vacuum to obtain an ion exchange resin catalyst, designated Cat-a2, having the following structural formula:
[ example 5 ] preparation of ion exchange resin
A monomer mixture solution containing an initiator (60.0 g of styrene, 1.0 g of divinylbenzene, 1.6 g of octavinyl silsesquioxane and 1.0 g of benzoyl peroxide are added into a 500ml three-neck flask, the solution is stirred and reacted for 0.5 hour at 70 ℃, a stirrer is started, a mixed solution of 200ml of deionized water and 4 g of polyvinyl alcohol is added, the temperature is increased to 85 ℃, the reaction is carried out for 3 hours, the temperature is increased to 90 ℃, the reaction is carried out for 9 hours, and finally the temperature is increased to 100 ℃, and the reaction is carried out for 10 hours. After the reaction is finished, pouring out the upper layer liquid, washing with hot water at 85 ℃, washing with cold water, filtering, drying in an oven at 80 ℃, sieving, and collecting the composite microspheres B2 with the particle size of 0.35-0.60 mm.
Chloromethylation of the composite microspheres: adding 50 g of composite microsphere B2 and 200ml of chloroethyl ether into a 500ml three-neck flask, standing at room temperature for 6 hours, adding 30 g of zinc chloride serving as a catalyst, starting stirring, heating to 50 ℃ for reaction for 30 hours, cooling to room temperature after chloromethylation is finished, filtering out a chlorination mother solution, repeatedly washing with methanol, and drying at 100 ℃ for 8 hours to obtain the composite chlorine sphere B2.
Imidation: 50 g of composite chlorosphere B2 (the chlorine content is 4.7mmol Cl/g), 1-butylimidazole (235.0mmol) and 300ml of acetonitrile are added into a 500ml three-neck flask, the mixture reacts for 16 hours at 80 ℃, the mixture is cooled to room temperature and filtered, and the mixture is washed by ethyl acetate, 0.1mol/L HCl, deionized water and methanol in sequence and then dried for 12 hours at 60 ℃ in vacuum to obtain the composite imidazole microsphere B2.
Ion exchange: adding 40 g of composite imidazole microsphere B2 and 400ml of deionized water solution of NaBr with the concentration of 1.0mol/L into a 1000ml three-neck flask, and stirring at room temperature to perform an ion exchange reaction for 12 hours; subsequently, the solution was washed with deionized water until the pH of the washing solution became 7, and dried under vacuum to obtain an ion exchange resin catalyst, designated Cat-B2, having the following structural formula:
[ example 6 ] ion exchange resin preparation
A monomer mixture solution containing an initiator (42.5 g of styrene, 2.5 g of divinylbenzene, 0.1 g of octavinyl silsesquioxane and 2.0 g of benzoyl peroxide, which is stirred at 70 ℃ for 1.5 hours) was charged into a 500ml three-neck flask, a mixed solution of 200ml of deionized water and 4 g of polyvinyl alcohol was added, the temperature was raised to 85 ℃ for reaction for 3 hours, then raised to 90 ℃ for reaction for 9 hours, and finally raised to 100 ℃ for reaction for 10 hours. After the reaction is finished, pouring out the upper layer liquid, washing with hot water at 85 ℃, washing with cold water, filtering, drying in an oven at 80 ℃, sieving, and collecting the composite microspheres C2 with the particle size of 0.35-0.60 mm.
Chloromethylation of the composite microspheres: adding 20 g of composite microsphere C2 and 100 ml of 1, 4-dichloromethoxybutane into a 250ml three-neck flask, standing for 6 hours at room temperature, adding 8 g of zinc chloride as a catalyst, starting stirring, heating to 30 ℃ for reaction for 12 hours, cooling to room temperature after chloromethylation is finished, filtering out chlorinated mother liquor, repeatedly washing with methanol, and drying for 8 hours at 100 ℃ to obtain the composite chlorine sphere C2.
Imidation: 20 g of composite chlorosphere C2 (with the chlorine content of 1.6mmol Cl/g), 1-methylimidazole (32.0mmol) and 150ml of acetonitrile are added into a 250ml three-neck flask, the mixture reacts for 16 hours at the temperature of 90 ℃, the mixture is cooled to room temperature and filtered, and the mixture is washed by ethyl acetate, 0.1mol/L HCl, deionized water and methanol in sequence and then dried for 12 hours at the temperature of 60 ℃ in vacuum to obtain the composite imidazole microsphere C2.
Ion exchange: adding 20 g of composite imidazole/POSS microsphere C2 and 300ml of NaBr deionized water solution with the concentration of 0.5mol/L into a 500ml three-neck flask, and stirring at room temperature to perform an ion exchange reaction for 12 hours; followed by deionized water until the wash solution had a pH of 7 and dried under vacuum to give the ion exchange resin catalyst, designated Cat-C2, of the formula:
[ example 7 ] preparation of ion exchange resin
65.0 g of styrene, 1.0 g of divinylbenzene, 0.07 g of octavinyl silsesquioxane and 1.0 g of benzoyl peroxide are added into a 500ml three-neck flask, and a stirrer is started to stir for 0.5 hour; a mixed solution of 200ml of deionized water and 4 g of polyvinyl alcohol was added thereto, and stirred for 2 hours. Then gradually raising the temperature to 75 ℃ for reaction for 5 hours, then raising the temperature to 90 ℃ for reaction for 10 hours, and finally raising the temperature to 100 ℃ for reaction for 10 hours. After the reaction is finished, pouring out the upper layer liquid, washing with hot water at 85 ℃, washing with cold water, filtering, drying in an oven at 80 ℃, sieving, and collecting the composite microspheres A3 with the particle size of 0.35-0.60 mm.
Chloromethylation of the composite microsphere: adding 40 g of composite microspheres A3 and 250ml of chloromethyl ether into a 500ml three-neck flask, standing at room temperature for 3 hours, starting stirring, adding 10 g of zinc chloride as a catalyst, heating to 60 ℃ for reaction for 10 hours, cooling to room temperature after chloromethylation is finished, filtering out a chlorination mother solution, repeatedly washing with methanol, and drying at 100 ℃ for 8 hours to obtain the composite chlorine spheres A3.
Imidation: 30 g of composite chloro-sphere A3 (chlorine content is 3.4mmol Cl/g), 1-methylimidazole (102.0mmol) and 200ml of acetonitrile are added into a 500ml three-neck flask, the mixture reacts for 24 hours at 60 ℃, the temperature is cooled to room temperature, the mixture is filtered, the ethyl acetate, 0.1mol/L HCl, deionized water and methanol are sequentially used for washing, and then the mixture is dried for 12 hours at 60 ℃ in vacuum to obtain the composite imidazole microsphere A3.
Ion exchange: adding 30 g of composite imidazole microspheres A3 and 500ml of NaBr deionized water solution with the concentration of 0.1mol/L into a 1000ml three-neck flask, and stirring at room temperature to perform ion exchange reaction for 24 hours; subsequently, the solution was washed with deionized water until the pH of the washing solution became 7, and dried under vacuum to obtain an ion exchange resin catalyst, designated Cat-a3, having the following structural formula:
[ example 8 ] preparation of ion exchange resin
65.0 g of styrene, 1.0 g of divinylbenzene, 7.5 g of octavinyl silsesquioxane and 1.0 g of benzoyl peroxide are added into a 500ml three-neck flask, and a stirrer is started to stir for 0.5 hour; a mixed solution of 200ml of deionized water and 4 g of polyvinyl alcohol was added thereto, and stirred for 2 hours. Then gradually raising the temperature to 75 ℃ for reaction for 5 hours, then raising the temperature to 90 ℃ for reaction for 10 hours, and finally raising the temperature to 100 ℃ for reaction for 10 hours. After the reaction is finished, pouring out the upper layer liquid, washing with hot water at 85 ℃, washing with cold water, filtering, drying in an oven at 80 ℃, sieving, and collecting the composite microspheres A5 with the particle size of 0.35-0.60 mm.
Chloromethylation of the composite microsphere: adding 40 g of composite microspheres A4 and 250ml of chloromethyl ether into a 500ml three-neck flask, standing at room temperature for 3 hours, starting stirring, adding 10 g of zinc chloride as a catalyst, heating to 60 ℃ for reaction for 10 hours, cooling to room temperature after chloromethylation is finished, filtering out a chlorination mother solution, repeatedly washing with methanol, and drying at 100 ℃ for 8 hours to obtain the composite chlorine spheres A4.
Imidation: 30 g of composite chloro-sphere A4 (chlorine content is 3.4mmol Cl/g), 1-methylimidazole (102.0mmol) and 200ml of acetonitrile are added into a 500ml three-neck flask, the mixture reacts for 24 hours at 60 ℃, the temperature is cooled to room temperature, the mixture is filtered, the ethyl acetate, 0.1mol/L HCl, deionized water and methanol are sequentially used for washing, and then the mixture is dried for 12 hours at 60 ℃ in vacuum to obtain the composite imidazole microsphere A4.
Ion exchange: adding 30 g of composite imidazole microspheres A4 and 500ml of NaBr deionized water solution with the concentration of 0.1mol/L into a 1000ml three-neck flask, and stirring at room temperature to perform ion exchange reaction for 24 hours; subsequently, the solution was washed with deionized water until the pH of the washing solution became 7, and dried under vacuum to obtain an ion exchange resin catalyst, designated Cat-a4, having the following structural formula:
[ example 9 ] preparation of ion exchange resin
65.0 g of styrene, 1.0 g of divinylbenzene, 11.8 g of octavinyl silsesquioxane and 1.0 g of benzoyl peroxide are added into a 500ml three-neck flask, and a stirrer is started to stir for 0.5 hour; a mixed solution of 200ml of deionized water and 4 g of polyvinyl alcohol was added thereto, and stirred for 2 hours. Then gradually raising the temperature to 75 ℃ for reaction for 5 hours, then raising the temperature to 90 ℃ for reaction for 10 hours, and finally raising the temperature to 100 ℃ for reaction for 10 hours. After the reaction is finished, pouring out the upper layer liquid, washing with hot water at 85 ℃, washing with cold water, filtering, drying in an oven at 80 ℃, sieving, and collecting the composite microspheres A5 with the particle size of 0.35-0.60 mm.
Chloromethylation of the composite microsphere: adding 40 g of composite microspheres A5 and 250ml of chloromethyl ether into a 500ml three-neck flask, standing at room temperature for 3 hours, starting stirring, adding 10 g of zinc chloride as a catalyst, heating to 60 ℃ for reaction for 10 hours, cooling to room temperature after chloromethylation is finished, filtering out a chlorination mother solution, repeatedly washing with methanol, and drying at 100 ℃ for 8 hours to obtain the composite chlorine spheres A5.
Imidation: 30 g of composite chloro-sphere A5 (chlorine content is 3.4mmol Cl/g), 1-methylimidazole (102.0mmol) and 200ml of acetonitrile are added into a 500ml three-neck flask, the mixture reacts for 24 hours at 60 ℃, the temperature is cooled to room temperature, the mixture is filtered, the ethyl acetate, 0.1mol/L HCl, deionized water and methanol are sequentially used for washing, and then the mixture is dried for 12 hours at 60 ℃ in vacuum to obtain the composite imidazole microsphere A5.
Ion exchange: adding 30 g of composite imidazole microspheres A5 and 500ml of NaBr deionized water solution with the concentration of 0.1mol/L into a 1000ml three-neck flask, and stirring at room temperature to perform ion exchange reaction for 24 hours; subsequently, the solution was washed with deionized water until the pH of the washing solution became 7, and dried under vacuum to obtain an ion exchange resin catalyst, designated Cat-a5, having the following structural formula:
[ example 10 ] preparation of ion exchange resin
65.0 g of styrene, 1.0 g of divinylbenzene and 1.0 g of benzoyl peroxide are added into a 500ml three-neck flask, and a stirrer is started to stir for 0.5 hour; a mixed solution of 200ml of deionized water and 4 g of polyvinyl alcohol was added thereto, and stirred for 2 hours. Then gradually raising the temperature to 75 ℃ for reaction for 5 hours, then raising the temperature to 90 ℃ for reaction for 10 hours, and finally raising the temperature to 100 ℃ for reaction for 10 hours. After the reaction is finished, pouring out the upper layer liquid, washing with hot water at 85 ℃, washing with cold water, filtering, drying in an oven at 80 ℃, sieving, and collecting the composite microspheres A6 with the particle size of 0.35-0.60 mm.
Chloromethylation of the composite microsphere: adding 40 g of composite microspheres A6 and 250ml of chloromethyl ether into a 500ml three-neck flask, standing at room temperature for 3 hours, starting stirring, adding 10 g of zinc chloride as a catalyst, heating to 60 ℃ for reaction for 10 hours, cooling to room temperature after chloromethylation is finished, filtering out a chlorination mother solution, repeatedly washing with methanol, and drying at 100 ℃ for 8 hours to obtain the composite chlorine spheres A6.
Imidation: 30 g of composite chloro-sphere A6 (chlorine content is 3.4mmol Cl/g), 1-methylimidazole (102.0mmol) and 200ml of acetonitrile are added into a 500ml three-neck flask, the mixture reacts for 24 hours at 60 ℃, the temperature is cooled to room temperature, the mixture is filtered, the ethyl acetate, 0.1mol/L HCl, deionized water and methanol are sequentially used for washing, and then the mixture is dried for 12 hours at 60 ℃ in vacuum to obtain the composite imidazole microsphere A6.
Ion exchange: adding 30 g of composite imidazole microspheres A6 and 500ml of NaBr deionized water solution with the concentration of 0.1mol/L into a 1000ml three-neck flask, and stirring at room temperature to perform ion exchange reaction for 24 hours; subsequently, the solution was washed with deionized water until the pH of the washing solution became 7, and dried under vacuum to obtain an ion exchange resin catalyst, designated Cat-a6, having the following structural formula:
[ example 11 ] ion exchange resin preparation
65.0 g of styrene, 1.0 g of divinylbenzene and 1.0 g of benzoyl peroxide are added into a 500ml three-neck flask, and a stirrer is started to stir for 0.5 hour; a mixed solution of 200ml of deionized water and 4 g of polyvinyl alcohol was added thereto, and stirred for 2 hours. Then gradually raising the temperature to 75 ℃ for reaction for 5 hours, then raising the temperature to 90 ℃ for reaction for 10 hours, and finally raising the temperature to 100 ℃ for reaction for 10 hours. After the reaction is finished, pouring out the upper layer liquid, washing with hot water at 85 ℃, washing with cold water, filtering, drying in an oven at 80 ℃, sieving, and collecting the microspheres A7 with the particle size of 0.35-0.60 mm.
Chloromethylation of microspheres: adding 40 g of microspheres A1 and 250ml of chloromethyl ether into a 500ml three-neck flask, standing at room temperature for 3 hours, starting stirring, adding 10 g of zinc chloride as a catalyst, heating to 60 ℃ for reaction for 10 hours, cooling to room temperature after chloromethylation is finished, filtering out a chlorination mother solution, repeatedly washing with methanol, and drying at 100 ℃ for 8 hours to obtain the chlorine spheres A7.
Imidation: 30 g of chlorine ball A7 (chlorine content is 3.4mmol Cl/g), imidazole (102.0mmol) and 200ml of acetonitrile are added into a 500ml three-neck flask, and the mixture reacts for 24 hours at 80 ℃, is cooled to room temperature, is filtered, is washed by ethyl acetate, 0.1mol/L HCl, deionized water and methanol in sequence, and is dried for 12 hours at 60 ℃ in vacuum to obtain the imidazole microsphere A7.
POSS (posterization): 30 g of imidazole microsphere A7 (the imidazole group content is 3.1mmol/g), 9.3 g of octachloromethylsilsesquioxane and 300ml of tetrahydrofuran are added into a 500ml three-neck flask, and after the reaction is finished, the mixture is filtered and washed by tetrahydrofuran and deionized water in sequence to obtain the imidazole/POSS microsphere A7 at 100 ℃ for 24 hours.
Ion exchange: adding 30 g of imidazole/POSS microspheres A7 and 500ml of 0.1mol/L NaBr deionized water solution into a 1000ml three-neck flask, and stirring at room temperature to perform an ion exchange reaction for 24 hours; subsequently, the solution was washed with deionized water until the pH of the washing solution became 7, and dried under vacuum to obtain an ion exchange resin catalyst, designated Cat-a7, having the following structural formula:
[ example 12 ]
The ion exchange resin prepared [ example 1 ] was used for the addition reaction of alkylene oxide and carbon dioxide under the following experimental conditions: under the protection of high-purity nitrogen, 50.0 g of ethylene oxide and 7.5 g of resin catalyst Cat-A1 are added into a 300ml autoclave, and 1.0MPa of CO is charged2Heating to 120 deg.C, and charging CO2Maintaining the reaction pressure at 2.0MPa, reacting for 4 hours, filtering to remove the catalyst, and measuring the conversion rate C of the ethylene oxideEO96.7% ethylene carbonate selectivity SECThe content was 99.3%.
[ examples 13 to 27 ]
The kind of the resin catalyst, the reaction temperature and the reaction pressure were changed, and the other reaction conditions were the same as in example 12, and the catalytic reaction of ethylene oxide and carbon dioxide was carried out, and the analysis results after the reaction are shown in Table 1.
TABLE 1
[ example 28 ]
The catalyst Cat-a1 used in example 12 was filtered, washed, dried and then catalyzed again according to the reaction procedure and conditions in example 12 to the reaction of ethylene oxide and carbon dioxide to obtain the results of catalyst recycle 2 times, see table 2. And analogizing to the above, and respectively carrying out catalytic reactions with the cycle times of 3-5 times, wherein the results are shown in Table 2.
TABLE 2
Number of cycles
CEO％
SEC％
2
95.6
99.0
3
95.9
99.1
4
95.5
99.2
5
95.3
98.9
[ examples 29 to 32 ]
The catalyst prepared in [ example 1 ] was used for the addition reaction of other alkylene oxides with carbon dioxide under the following conditions: under the protection of high-purity nitrogen, 50.0 g of alkylene oxide and 7.5 g of resin catalyst are added into a 300ml autoclave, and 1.0MPa of CO is charged2Heating to 120 deg.C, and charging CO2The reaction pressure was maintained at 2.0MPa, the catalyst was removed by filtration after 4 hours of reaction, and the conversion of alkylene oxide and the selectivity of the obtained carbonate were measured. The results are shown in Table 3.
TABLE 3
[ COMPARATIVE EXAMPLE 1 ]
The catalyst SiO is prepared according to the preparation method of the literature Catal.Sci.Technol, 2014,4, 1598-2-ethane-Br used in the addition reaction of styrene oxide with carbon dioxide, under the following conditions: under the protection of high-purity nitrogen, 50.0 g of styrene oxide and 7.5 g of catalyst are added into a 300ml autoclave, and 1.0MPa of CO is charged2Heating to 120 deg.C, and charging CO2The reaction pressure was maintained at 2.0MPa, the catalyst was removed by filtration after 4 hours of reaction, and the conversion of styrene oxide and the selectivity of the styrene cyclic carbonate obtained were measured. The results are shown in Table 4.
[ COMPARATIVE EXAMPLE 2 ]
According to the preparation method of the Catalysis Today 2013,200, 117-124, SBA-15-IL3Br catalyst is prepared and used for the addition reaction of propylene oxide and carbon dioxide, and the conditions are as follows: under the protection of high-purity nitrogen, 50.0 g of propylene oxide and 7.5 g of catalyst are added into a 300ml autoclave, and 1.0MPa of CO is charged2Heating to 120 deg.C, and charging CO2Maintaining the reaction pressure at 2.0MPa, filtering to remove the catalyst after reacting for 4 hours,the conversion of propylene oxide was determined, as well as the selectivity of the propylene carbonate obtained. The results are shown in Table 4.
[ COMPARATIVE EXAMPLE 3 ]
The catalyst Poly [ bvbim ] is prepared according to the preparation method of the document Green chem, 2013,15, 1584-one 1589]Cl, which is used in the addition reaction of styrene oxide with carbon dioxide, under the following conditions: under the protection of high-purity nitrogen, 50.0 g of styrene oxide and 7.5 g of catalyst are added into a 300ml autoclave, and 1.0MPa of CO is charged2Heating to 120 deg.C, and charging CO2The reaction pressure was maintained at 2.0MPa, the catalyst was removed by filtration after 4 hours of reaction, and the conversion of styrene oxide and the selectivity of the styrene cyclic carbonate obtained were measured. The results are shown in Table 4.
TABLE 4
It should be noted that the above-mentioned embodiments are only for explaining the present invention, and do not set any limit to the present invention. The present invention has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. The invention can be modified, as prescribed, within the scope of the claims and without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, but rather extends to all other methods and applications having the same functionality.