A quaternary phosphonium salt catalyst for cycloaddition reactions, its preparation method and application

Abstract

This invention discloses a quaternary phosphonium salt catalyst for cycloaddition reactions, its preparation method, and its application. The quaternary phosphonium salt catalyst uses a styrene-based crosslinked copolymer resin containing inorganic nanomaterials as a matrix, and multiple quaternary phosphonium salt molecular chains of formula (I) are grafted onto the matrix: In formula (I), R 1 R 2 R 3 R 4 Each of R1, R2, and R3 is independently selected from one of hydrogen, alkyl, aromatic, and ester groups, and each of R1, R2, and R3 is independently selected from one of alkyl and aromatic groups, where n > 0, X ‑ P is an anion, and P represents phosphorus. The quaternary phosphonium salt catalyst for the cycloaddition reaction described in this invention has a higher concentration of active centers on its surface. Thus, during the cycloaddition reaction, the reactants do not need to diffuse into the interior of the catalyst spheres because their surface already possesses higher reactivity.

Description

Technical Field

[0001] This invention belongs to the field of catalysts, and particularly relates to cycloaddition reaction catalysts, especially to a quaternary phosphonium salt catalyst for cycloaddition reactions, its preparation method and application. Background Technology

[0002] Alkyl carbonates can be prepared by the addition reaction of epoxides with carbon dioxide and have a wide range of applications. In recent years, with the rapid development of the new energy vehicle industry, the demand for electrolytes has been increasing, leading to a gradual increase in the demand for alkyl carbonates. The production of ethylene carbonate mainly includes urea alcoholysis, transesterification, and the esterification addition method of ethylene oxide (EO) / carbon dioxide. Among these, the esterification addition method of ethylene oxide with carbon dioxide aligns with the scientific principles of atom economy and green chemistry. This method can effectively utilize carbon dioxide to synthesize fine chemicals and is currently widely used and promoted.

[0003] Catalysts for the ethylene oxide / carbon dioxide addition system currently include metal oxides, metal complexes, alkali metals, quaternary ammonium salts and quaternary phosphonium salts, as well as ionic liquids.

[0004] Compared to homogeneous catalysts, heterogeneous catalysts immobilize the active components on a catalyst support through physical or chemical methods, which facilitates the separation of subsequent products from the catalyst. The catalyst is also easy to regenerate and can be reused multiple times.

[0005] Although heterogeneous catalytic systems have many advantages, they still have some shortcomings, such as catalyst performance, production cost, and the universality of raw materials. Therefore, researching and developing a highly active, stable, and easily separable heterogeneous catalytic system to improve the catalytic performance of heterogeneous catalysts remains a hot topic in epoxide / carbon dioxide addition reaction research. Summary of the Invention

[0006] To overcome the problems existing in the prior art, the present invention provides a quaternary phosphonium salt catalyst for cycloaddition reactions, its preparation method and application. Compared with the prior art, the catalyst has a higher concentration of active groups on its surface. The catalyst has the advantages of good catalyst activity, high stability, easy separation of reaction products, and continuous recycling of the catalyst multiple times.

[0007] One objective of this invention is to provide a quaternary phosphonium salt catalyst for cycloaddition reactions, which uses a styrene-based crosslinked copolymer resin containing inorganic nanomaterials as a matrix, and grafts multiple quaternary phosphonium salt molecular chains of formula (I) onto the matrix:

[0008]

[0009] In equation (I), R 1 R 2R 3 R 4 Each of R1, R2, and R3 is independently selected from one of hydrogen, alkyl, aromatic, and ester groups, and each of R1, R2, and R3 is independently selected from one of alkyl and aromatic groups, where n > 0, X - It is an anion, and P is phosphorus.

[0010] The quaternary phosphonium salt catalyst for cycloaddition reaction described in this invention has a higher concentration of active centers on its surface. Thus, during the cycloaddition reaction, the reactants do not need to diffuse into the interior of the catalyst spheres because their surface has higher reactivity.

[0011] In a preferred embodiment, in formula (I), R1, R2, R3, and R4 are each independently selected from hydrogen, C1-C30 alkyl groups, C6-C30 aromatic groups, and C2-C30 ester groups; R1, R2, and R3 are each independently selected from C1-C10 alkyl groups and C6-C20 aromatic groups; n = 4-100; X - It is at least one of a halide anion and an organic acid anion.

[0012] In a further preferred embodiment, in formula (I), R1, R2, R3, and R4 are each independently selected from hydrogen, C1-C20 alkyl, C6-C20 aromatic, and C2-C20 ester groups; R1, R2, and R3 are each independently selected from C1-C5 alkyl and C6-C10 aromatic groups; n = 4-40; X - It is one of chloride ions, bromide ions, iodide ions, and formate ions.

[0013] In a preferred embodiment, based on 100 wt% of the weight of the quaternary phosphonium salt catalyst, the weight of the styrene-based crosslinked copolymer resin containing inorganic nanomaterials is 5 wt% to 50 wt% (e.g., 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, or 50 wt%), and the weight of the quaternary phosphonium salt molecular chains shown in multiple formulas (I) is 50 wt% to 95 wt% (e.g., 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, or 95 wt%).

[0014] In a further preferred embodiment, based on 100 wt% of the weight of the quaternary phosphonium salt catalyst, the weight of the styrene-based crosslinked copolymer resin containing inorganic nanomaterials is 10 wt% to 40 wt%, and the weight of the quaternary phosphonium salt molecular chains shown in formula (I) is 60 wt% to 90 wt%.

[0015] In a preferred embodiment, the inorganic nanomaterial is selected from at least one of carbon nanotubes, graphene, POSS-type compounds, graphite, and fullerene.

[0016] In a further preferred embodiment, based on the total weight of the styrene-based crosslinked copolymer resin containing inorganic nanomaterials being 100 wt%, the weight content of inorganic nanomaterials is 0.1 wt%-4 wt%, preferably 0.1 wt%-3 wt%, and more preferably 0.2 wt%-2 wt%.

[0017] For example, based on 100 wt% of the total weight of the styrene-based crosslinked copolymer resin containing inorganic nanomaterials, the weight of the inorganic nanomaterials is 0.1 wt%, 0.2 wt%, 0.4 wt%, 0.6 wt%, 0.8 wt%, 1 wt%, 1.4 wt%, 1.8 wt%, 2.2 wt%, 2.6 wt%, 2.8 wt%, 3.2 wt%, 3.6 wt%, or 4 wt%.

[0018] In a preferred embodiment, the styrene-based crosslinked copolymer resin containing inorganic nanomaterials is obtained as follows: components including styrene monomers, crosslinking agents, inorganic nanomaterials, and initiators are mixed and copolymerized to obtain the styrene-based crosslinked copolymer resin containing inorganic nanomaterials.

[0019] In a further preferred embodiment, the styrene monomer is selected from styrene and its derivatives, preferably from at least one of styrene, halogenated styrene (e.g., chlorostyrene), halogenated alkylstyrene (e.g., p-chloromethylstyrene), α-methylstyrene, and alkoxy-substituted styrene.

[0020] In a further preferred embodiment, the crosslinking agent is selected from at least one of divinylbenzene, divinylbenzene, ethylene glycol dimethacrylate, diallylbenzene, and divinylphenylmethane.

[0021] The second objective of this invention is to provide a method for preparing a quaternary phosphonium salt catalyst for cycloaddition reactions, preferably for preparing the quaternary phosphonium salt catalyst for cycloaddition reactions described in the first objective of this invention. The preparation method includes: sequentially treating the styrene-based crosslinked copolymer resin containing inorganic nanomaterials as follows: (1) optionally chloromethylating, (2) initiating polymerization of styrene monomers in the presence of a catalyst and ligands, followed by optional chloromethylating, (3) quaternization reaction, and (4) ion exchange treatment to obtain the quaternary phosphonium salt catalyst for cycloaddition reactions.

[0022] In this invention, the chloromethylation treatment can be carried out using a chloromethylation reaction disclosed in the prior art, such as chloromethyl ether-zinc chloride or formaldehyde-hydrogen chloride-zinc chloride, as long as the chloromethylation of the benzene ring can be achieved. The chloromethyl ether refers to a chloromethyl alkyl ether, for example, selected from chloromethyl methyl ether and / or chloromethyl ethyl ether.

[0023] In a preferred embodiment, the styrene-based crosslinked copolymer resin containing inorganic nanomaterials is obtained as follows: raw materials including styrene monomers, crosslinking agents, inorganic nanomaterials, and initiators are mixed and copolymerized to obtain the styrene-based crosslinked copolymer resin containing inorganic nanomaterials.

[0024] In a further preferred embodiment, the styrene monomer is selected from styrene and its derivatives, preferably from at least one of styrene, p-chloromethylstyrene, α-methylstyrene, and alkoxy-substituted styrene; and / or, the crosslinking agent is selected from at least one of divinylbenzene, divinylbenzene, ethylene glycol dimethacrylate, diallylbenzene, and divinylphenylmethane; and / or, the initiator is selected from at least one of benzoyl peroxide, azobisisobutyronitrile, azobisisoheptanenitrile, lauroyl peroxide, and cumene hydroperoxide.

[0025] In a further preferred embodiment, based on 100 wt% of the total weight of the raw materials, the inorganic nanomaterials contain 0.1 wt% to 4 wt%, preferably 0.1 wt% to 3 wt%, more preferably 0.2 wt% to 2 wt%; and / or, the styrene monomer contains 82 wt% to 95 wt%; and / or, the crosslinking agent contains 2 wt% to 15 wt%; and / or, the initiator contains 0.1 wt% to 3 wt%.

[0026] For example, based on a total weight of 100 wt% of the raw materials, the weight content of inorganic nanomaterials is 0.1 wt%, 0.2 wt%, 0.4 wt%, 0.6 wt%, 0.8 wt%, 1 wt%, 1.4 wt%, 1.8 wt%, 2.2 wt%, 2.6 wt%, 2.8 wt%, 3.2 wt%, 3.6 wt%, or 4 wt%; and / or, the mass content of the styrene monomers is 82 wt%, 83 wt%, 84 wt%, 85 wt%, or 86 wt%. The crosslinking agent content is 2 wt%, 4 wt%, 6 wt%, 8 wt%, 10 wt%, 12 wt%, 14 wt%, or 15 wt%; and / or the initiator content is 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, or 3 wt%.

[0027] In a preferred embodiment, when preparing the styrene-based crosslinked copolymer resin containing inorganic nanomaterials, the raw material further includes gelatin, preferably a dissolved aqueous solution of gelatin.

[0028] In this invention, the styrene-based crosslinked copolymer resin containing inorganic nanomaterials can be purchased directly or prepared using the above method. The conditions for preparing the styrene-based crosslinked copolymer resin containing inorganic nanomaterials can be the commonly used conditions disclosed in the prior art.

[0029] In a preferred embodiment, when the styrene-based crosslinked copolymer resin containing inorganic nanomaterials is prepared using halogen-substituted styrene and / or halogen-substituted alkyl styrene as styrene monomers, step (1) is not performed, that is, the styrene-based crosslinked copolymer resin containing inorganic nanomaterials is not subjected to chloromethylation treatment.

[0030] In this case, styrene monomer polymerization can be directly initiated on the surface of the styrene-based crosslinked copolymer resin of the inorganic nanomaterial.

[0031] In another preferred embodiment, when the styrene-based crosslinked copolymer resin containing inorganic nanomaterials is prepared using other styrene monomers besides halogen-substituted styrene and halogen-substituted alkyl styrene, step (1) is performed, that is, the obtained styrene-based crosslinked copolymer resin containing inorganic nanomaterials is subjected to chloromethylation treatment.

[0032] In a preferred embodiment, when the styrene monomer in step (2) is selected from halogenated styrene and / or halogenated alkyl styrene, step (3) is not performed after step (2), and step (4) is performed directly.

[0033] In another preferred embodiment, when the styrene monomer in step (2) is selected from other styrene monomers besides halogenated styrene and halogenated alkyl styrene, step (3) is performed after step (2) is completed.

[0034] In a preferred embodiment, in step (2), the catalyst is selected from cuprous halides, preferably from cuprous chloride and / or bromide ketones; and / or, the ligand is selected from nitrogen-based ligands, preferably from at least one of 2,2'-bipyridine, PMDETA, pyridinium imine, DETA, TREN, and CYCLAM.

[0035] In a further preferred embodiment, the molar ratio of the catalyst to the ligand is 1:(1-10), preferably 1:(2-5), for example 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10.

[0036] In a preferred embodiment, in step (2), the polymerization is carried out under a protective atmosphere, such as nitrogen.

[0037] In a preferred embodiment, in step (2), the total weight ratio of the catalyst and ligand to the product of step (1) is (0.08 to 0.4):1, preferably (0.1 to 0.4):1, for example 0.08:1, 0.1:1, 0.12:1, 0.14:1, 0.16:1, 0.18:1, 0.2:1, 0.22:1, 0.25:1, 0.3:1 or 0.4:1.

[0038] In a preferred embodiment, in step (2), the weight ratio of the styrene monomer to the product of step (1) is (1-6):1, preferably (2-5):1, for example 1:1, 2:1, 3:1, 4:1, 5:1 or 6:1.

[0039] When step (1) is not performed, the product of step (1) refers to the styrene-based crosslinked copolymer resin containing inorganic nanomaterials.

[0040] In this invention, the polymerization conditions in step (2) can be the commonly used conditions disclosed in the prior art, such as being carried out at 70 to 150°C for 0.2 to 6 hours.

[0041] In this invention, chloromethyl ether and zinc chloride are preferably used for the chloromethylation reaction. Preferably, the weight ratio of chloromethyl ether to the raw material to be chloromethylated is (2-6):1, for example, 2:1, 3:1, 4:1, 5:1 or 6:1; the weight ratio of zinc chloride to the raw material to be chloromethylated is (0.2-1):1, for example, 0.2:1, 0.4:1, 0.6:1, 0.8:1 or 1:1. The chloromethyl ether refers to a chloromethyl alkyl ether, for example selected from chloromethyl methyl ether and / or chloromethyl ethyl ether.

[0042] In a preferred embodiment, in step (3), the quaternization reaction is carried out using the P-containing compound of formula (II):

[0043]

[0044] In formula (II), R1, R2, and R3 are each independently selected from alkyl and aromatic groups, preferably from alkyl groups of C1 to C10 and aromatic groups of C6 to C20, and more preferably from alkyl groups of C1 to C5 and aromatic groups of C6 to C10.

[0045] In a further preferred embodiment, the weight ratio of the P-containing compound shown in formula (II) to the product of step (2) is (0.5 to 3.5):1, preferably (1.0 to 2.0):1.

[0046] In a preferred embodiment, the quaternization reaction in step (3) is carried out in an organic solvent.

[0047] In a further preferred embodiment, the organic solvent is selected from at least one of acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, and tetrahydrofuran.

[0048] In a further preferred embodiment, the volume ratio (g / ml) of the organic solvent to the product of step (2) is (5-10):1, preferably (6-8):1, for example 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1.

[0049] In a preferred embodiment, in step (3), the temperature of the quaternization reaction is 50–150°C and the time is 12–36 h.

[0050] For example, the temperature of the quaternization reaction is 50°C, 60°C, 80°C, 100°C, 120°C, 140°C or 150°C, and the time is 12h, 15h, 18h, 20h, 22h, 25h, 28h, 30h, 32h, 34h or 36h.

[0051] In a preferred embodiment, a post-treatment, preferably washing, is performed after the quaternization reaction.

[0052] In a further preferred embodiment, the post-treatment includes washing with organic solvent I, an aqueous solution of inorganic acid, water, and organic solvent II in sequence.

[0053] In a further preferred embodiment, the organic solvent I is selected from at least one of ethyl acetate, methyl formate, and methyl acetate; and / or, the inorganic acid aqueous solution is selected from at least one of hydrochloric acid aqueous solution, sulfuric acid aqueous solution, and nitric acid aqueous solution; and / or, the organic solvent II is selected from at least one of methanol, ethanol, and propanol.

[0054] In a preferred embodiment, the ion exchange treatment in step (4) is carried out in a saline aqueous solution.

[0055] In a further preferred embodiment, the salt is selected from at least one of the following: halide salts, sodium formate, potassium formate, magnesium formate, calcium formate, sodium acetate, potassium acetate, magnesium acetate, and calcium acetate.

[0056] Preferably, the concentration of the saline aqueous solution is 0.05–2 mol / L, more preferably 0.1–1 mol / L, for example 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L or 1 mol / L.

[0057] The amount of the salt solution used needs to cover the product of step (3). Preferably, but not limited to, the ratio (g / ml) of the weight of the product of step (3) to the volume of the salt solution is 1:(5-30), preferably (8-20):1, for example 1:5, 1:8, 1:10, 1:12, 1:15, 1:18, 1:20, 1:25 or 1:30.

[0058] In a preferred embodiment, the ion exchange treatment is performed for 3 to 24 hours, preferably 5 to 10 hours, for example 3 hours, 5 hours, 8 hours, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, 22 hours or 24 hours.

[0059] The third objective of this invention is to provide a quaternary phosphonium salt catalyst for cycloaddition reactions obtained by the preparation method described in the second objective of this invention.

[0060] The fourth objective of this invention is to provide the application of the quaternary phosphonium salt catalyst for cycloaddition reaction described in the first objective of this invention, or the quaternary phosphonium salt catalyst for cycloaddition reaction obtained by the preparation method described in the second objective of this invention, in the preparation of cyclic carbonates by cycloaddition reaction of alkyl epoxides / carbon dioxide.

[0061] Preferably, the epoxide alkane has the following general formula:

[0062]

[0063] Wherein, R4-R7 may be the same or different, and each is independently selected from hydrogen, C1-C6 alkyl, C1-C6 haloalkyl or C6-C10 aryl, preferably from hydrogen, methyl, ethyl, propyl, butyl or phenyl; preferably, the alkyl oxide is selected from ethylene oxide and / or propylene oxide.

[0064] In a preferred embodiment, the weight ratio of the catalyst to the epoxide is (0.001-1):1, preferably (0.1-0.3):1.

[0065] For example, the weight ratio of the catalyst to the epoxide is 0.001:1, 0.01:1, 0.05:1, 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, or 1:1.

[0066] In a preferred embodiment, the cycloaddition reaction is carried out at a temperature of 60-180°C, preferably 100-160°C, at a pressure of 0.1-10.0 MPa, and for a time of 1-12 h.

[0067] For example, the temperature of the cycloaddition reaction is 60°C, 80°C, 100°C, 120°C, 140°C, 160°C, or 180°C. The pressure is 0.1 MPa, 0.5 MPa, 1 MPa, 2 MPa, 4 MPa, 6 MPa, 8 MPa, or 10.0 MPa, and the time is 1 h, 2 h, 4 h, 6 h, 8 h, 10 h, or 12 h.

[0068] In a further preferred embodiment, the cycloaddition reaction is carried out at a temperature of 100-160°C, a pressure of 2.0-5.0 MPa, and a time of 2-5 hours.

[0069] For example, the cycloaddition reaction is carried out at a temperature of 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, or 160°C, at a pressure of 2.0 MPa, 2.5 MPa, 3.0 MPa, 3.5 MPa, 4.0 MPa, 4.5 MPa, or 5.0 MPa, and for a time of 2 h, 3 h, 4 h, or 5 h.

[0070] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values; these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. In the following, various technical solutions can, in principle, be combined with each other to obtain new technical solutions, which should also be considered as specifically disclosed herein.

[0071] Compared with the prior art, the present invention has the following beneficial effects:

[0072] (1) The quaternary phosphonium salt catalyst for the cycloaddition reaction described in this invention contains more quaternary phosphonium salt active sites on its surface;

[0073] (2) The quaternary phosphonium salt catalyst described in this invention has the advantages of high conversion rate of alkylene oxide and high selectivity of alkylene carbonate when used in the addition reaction of alkylene oxide with carbon dioxide to prepare alkylene carbonate.

[0074] (3) The quaternary phosphonium salt catalyst for cycloaddition reaction described in this invention can be used in the addition reaction of epoxides and carbon dioxide to prepare alkylene carbonates. The catalyst has high activity, good stability, and the product after reaction is easy to separate. The catalyst can be used continuously multiple times and has a long service life. Attached Figure Description

[0075] Figure 1 The infrared spectrum of the composite quaternary phosphonium microspheres A1 prepared in Example 1 is shown. Detailed Implementation

[0076] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0077] It should also be noted that the various specific technical features described in the following embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the various possible combinations will not be described separately in this invention.

[0078] Furthermore, various embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention. The resulting technical solutions are part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0079] Unless otherwise specified, the raw materials used in the examples and comparative examples are all publicly available in the prior art, such as those that can be directly purchased or prepared according to publicly available methods. The chloromethyl ether mentioned in the examples and comparative examples is chloromethyl methyl ether.

[0080] In the examples, the chlorine content was determined by oxygen flask-mercury metric method.

[0081]

Example 1

[0082] 60.0 g of styrene, 4.5 g of divinylbenzene, and 0.6 g of benzoyl peroxide initiator were placed in a 500 mL three-necked flask and stirred at 60 °C for 1.0 h. Then, 0.7 g of octavinyl POSS was added, and stirring continued for 1 h for prepolymerization. 300 mL of deionized water containing 2.9 g of gelatin was added. The stirring speed was adjusted, and the temperature was gradually increased to 78 °C for 4 h; then increased to 90 °C for 4 h; and finally increased to 98 °C for 5 h. After the reaction was complete, the supernatant was decanted, washed with 80 °C hot water, then washed with cold water, filtered, dried in a vacuum oven at 60 °C, sieved, and composite microspheres with a particle size in the range of 0.35–0.60 mm were collected.

[0083] 40 g of composite microspheres and 180 ml of chloromethyl ether were placed in a 500 ml three-necked flask and allowed to stand at room temperature for 3 hours. Then, stirring was started, and 16 g of zinc chloride was added as a catalyst. The temperature was raised to 60 °C and the reaction was carried out for 4 hours. After chloromethylation was completed, the mixture was cooled to room temperature, the chlorination mother liquor was filtered out, and the mixture was repeatedly washed with methanol and dried in a vacuum oven at 60 °C for 10 hours to obtain 46 g of composite chlorine microspheres (with a chlorine content of 10 wt%).

[0084] 40.0 g of composite chloride spheres and 150 ml of toluene were placed in a 500 ml flask and allowed to swell for 1 hour. Then, 80 g of styrene and 12 g of cuprous chloride / 2,2'-bipyridine (molar ratio 1:2) were added. The air in the flask was completely replaced with high-purity nitrogen, and the reaction was carried out at 110 °C for 2 hours. After the reaction was complete, the mixture was washed with tetrahydrofuran to obtain the composite modified resin (n≈7).

[0085] Add 50 g of composite modified resin and 250 ml of chloromethyl ether to a 500 ml three-necked flask, let stand at room temperature for 2 hours, start stirring, add 22 g of zinc chloride as a catalyst, heat to 50 °C and react for 10 hours. After chloromethylation is completed, cool to room temperature, filter out the chlorination mother liquor, wash repeatedly with methanol, and dry in a vacuum oven at 60 °C for 10 hours to obtain composite modified chlorine balls (chlorine content is 15 wt%).

[0086] Add 40 g of composite modified chlorine spheres, 70 g of tributylphosphine and 200 ml of acetonitrile to a 500 ml three-necked flask, react at 80 °C for 24 hours, cool to room temperature, filter, wash successively with ethyl acetate, 0.1 mol / L HCl, deionized water and methanol, and then dry under vacuum at 60 °C for 24 hours to obtain composite quaternary phosphonium microspheres A1.

[0087] Infrared spectroscopy was performed on the composite quaternary phosphonium microspheres A1 prepared in Example 1, confirming their successful preparation.

[0088] In a 1000ml three-necked flask, 40g of composite quaternary phosphonium microspheres A1 and 500ml of 0.5mol / L deionized NaBr aqueous solution were added to carry out an ion exchange reaction at room temperature for 10 hours with stirring. The solution was then washed with deionized water until the pH of the washing solution was 7, and after vacuum drying, the nanocomposite ion exchange resin catalyst Cat-1 was obtained.

[0089] In the nanocomposite ion exchange resin catalyst Cat-1, the weight content of the styrene crosslinked copolymer resin containing inorganic nanomaterials is 11.6 wt%, and the weight content of the molecular chain shown in formula (I) is 88.6 wt% (calculated based on the theoretical value after the chlorine content was determined).

[0090]

Example 2

[0091] The process of Example 1 was repeated, except that tributylphosphine was replaced with an equimolar amount of triphenylphosphine while other conditions remained unchanged, to obtain catalyst Cat-2.

[0092] Infrared spectroscopy of the composite quaternary phosphonium microspheres prepared in Example 2 confirmed their successful preparation.

[0093]

Example 3

[0094] The process of Example 1 was repeated, except that an equimolar amount of dimethylphenylphosphine was used to replace the tributylphosphine, while other conditions remained unchanged, to obtain catalyst Cat-3.

[0095] Infrared spectroscopy of the composite quaternary phosphonium microspheres prepared in Example 3 confirmed their successful preparation.

[0096]

Example 4

[0097] The process of Example 1 was repeated, except that "0.5 mol / L deionized water solution of NaBr" was replaced with "0.5 mol / L deionized water solution of NaCl", while other conditions remained unchanged, to obtain catalyst Cat-4.

[0098]

Example 5

[0099] The process of Example 1 was repeated, except that "0.5 mol / L deionized water solution of NaBr" was replaced with "0.5 mol / L deionized water solution of NaI", while other conditions remained unchanged, to obtain catalyst Cat-5.

[0100]

Example 6

[0101] 50.0 g of styrene, 5.6 g of divinylbenzene, and 1.2 g of azobisisobutyronitrile initiator were placed in a 500 mL three-necked flask and stirred at 60 °C for 1.0 h. Then, 0.9 g of carbon nanotubes were added, and stirring continued for 1 h for prepolymerization. 300 mL of deionized water containing 3.0 g of gelatin was added. The stirring speed was adjusted, and the temperature was gradually increased to 78 °C for 4 h; then increased to 90 °C for 5 h; and finally increased to 98 °C for 5 h. After the reaction was complete, the supernatant was poured off, washed with 80 °C hot water, then washed with cold water, filtered, dried in a vacuum oven at 60 °C, sieved, and composite microspheres with a particle size in the range of 0.35–0.60 mm were collected.

[0102] 40 g of composite microspheres and 180 ml of chloromethyl ether were placed in a 500 ml three-necked flask and allowed to stand at room temperature for 3 hours. Then, stirring was started, and 15 g of zinc chloride was added as a catalyst. The temperature was raised to 50 °C and the reaction was carried out for 7 hours. After chloromethylation was completed, the mixture was cooled to room temperature, the chlorination mother liquor was filtered out, and the mixture was washed repeatedly with methanol. The mixture was then dried in a vacuum oven at 60 °C for 10 hours to obtain 49 g of composite chlorine microspheres (chlorine content 13%).

[0103] 40.0 g of composite chloride spheres and 150 ml of toluene were placed in a 500 ml flask and allowed to swell for 2 hours. Then, 70 g of styrene and 15 g of cuprous chloride / 2,2'-bipyridine (molar ratio 1:2) were added. The air in the flask was completely replaced with high-purity nitrogen, and the reaction was carried out at 110 °C for 2 hours. After the reaction was complete, the mixture was washed with tetrahydrofuran to obtain the composite modified resin, n≈5.

[0104] Add 50 g of composite modified resin A6 and 250 ml of chloromethyl ether to a 500 ml three-necked flask, let stand at room temperature for 2 hours, start stirring, add 22 g of zinc chloride as a catalyst, heat to 50 °C and react for 12 hours. After chloromethylation is completed, cool to room temperature, filter out the chlorination mother liquor, wash repeatedly with methanol, and dry in a vacuum oven at 60 °C for 10 hours to obtain composite modified chlorine balls with a chlorine content of 15%.

[0105] Add 40 g of composite modified chlorine spheres, 80 g of tributylphosphine and 200 ml of N,N-dimethylformamide to a 500 ml three-necked flask, react at 120 °C for 24 hours, cool to room temperature, filter, and wash successively with methyl acetate, 0.1 mol / L H2SO4, deionized water and ethanol, and then dry under vacuum at 60 °C for 24 hours to obtain composite quaternary phosphonium microspheres.

[0106] Infrared spectroscopy of the composite quaternary phosphonium microspheres prepared in Example 6 confirmed their successful preparation.

[0107] In a 1000ml three-necked flask, 40g of composite quaternary phosphonium microspheres and 500ml of 0.5mol / L KBr deionized water solution were added to carry out an ion exchange reaction at room temperature for 10 hours with stirring. The solution was then washed with deionized water until the pH of the washing solution was 7, and after vacuum drying, the nanocomposite ion exchange resin catalyst Cat-6 was obtained.

[0108] In the nanocomposite ion exchange resin catalyst Cat-6, the weight content of the styrene crosslinked copolymer resin containing inorganic nanomaterials is 14 wt%, and the weight content of the molecular chain shown in formula (I) is 86 wt%.

[0109]

Example 7

[0110] 45.0 g of styrene, 2.0 g of diallylbenzene, and 0.8 g of benzoyl peroxide initiator were placed in a 500 mL three-necked flask and stirred at 60 °C for 1.0 h. Then, 0.15 g of graphene was added, and stirring continued for 1 h for prepolymerization. 300 mL of deionized water containing 3.0 g of gelatin was added. The stirring speed was adjusted, and the temperature was gradually increased to 78 °C for 4 h; then increased to 90 °C for 5 h; and finally increased to 98 °C for 5 h. After the reaction was complete, the supernatant was poured off, washed with 80 °C hot water, then washed with cold water, filtered, dried in a vacuum oven at 60 °C, sieved, and composite microspheres with a particle size in the range of 0.35–0.60 mm were collected.

[0111] 40 g of composite microspheres A7 and 200 ml of chloromethyl ether were placed in a 500 ml three-necked flask and allowed to stand at room temperature for 3 hours. Then, stirring was started, and 25 g of zinc chloride was added as a catalyst. The temperature was raised to 50 °C and the reaction was carried out for 12 hours. After chloromethylation was completed, the mixture was cooled to room temperature, the chlorination mother liquor was filtered out, and the mixture was washed repeatedly with methanol. The mixture was then dried in a vacuum oven at 60 °C for 10 hours to obtain 50 g of composite chlorine spheres (chlorine content 16%).

[0112] 40.0 g of composite chloride spheres and 150 ml of toluene were placed in a 500 ml flask and allowed to swell for 2 hours. Then, 200 g of styrene and 15 g of cuprous chloride / N,N,N',N,'N”-pentamethyldiethylenetriamine (molar ratio 1:3) were added. The air in the flask was completely replaced with high-purity nitrogen, and the reaction was carried out at 110 °C for 6 hours. After the reaction was complete, the mixture was washed with tetrahydrofuran to obtain the composite modified resin, n≈10.

[0113] Add 50 g of composite modified resin and 250 ml of chloromethyl ether to a 500 ml three-necked flask, let stand at room temperature for 2 hours, start stirring, add 22 g of zinc chloride as a catalyst, heat to 50 °C and react for 12 hours. After chloromethylation is completed, cool to room temperature, filter out the chlorination mother liquor, wash repeatedly with methanol, and dry in a vacuum oven at 60 °C for 10 hours to obtain composite modified chlorine balls with a chlorine content of 18%.

[0114] Add 40 g of composite modified chlorine spheres, 80 g of tributylphosphine and 200 ml of N,N-dimethylacetamide to a 500 ml three-necked flask, react at 120 °C for 24 hours, cool to room temperature, filter, wash successively with methyl acetate, 0.1 mol / L HNO3, deionized water and ethanol, and then dry under vacuum at 60 °C for 24 hours to obtain composite quaternary phosphonium microspheres.

[0115] Infrared spectroscopy of the composite quaternary phosphonium microspheres prepared in Example 7 confirmed their successful preparation.

[0116] In a 1000ml three-necked flask, 40g of composite quaternary phosphonium microspheres and 500ml of 0.5mol / L KBr deionized water solution were added to carry out an ion exchange reaction at room temperature for 10 hours with stirring. The solution was then washed with deionized water until the pH of the washing solution was 7, and then dried under vacuum to obtain the nanocomposite ion exchange resin catalyst Cat-7.

[0117] In the nanocomposite ion exchange resin catalyst Cat-7, the weight content of the styrene crosslinked copolymer resin containing inorganic nanomaterials is 6 wt%, and the weight content of the molecular chain shown in formula (I) is 94 wt%.

[0118] Comparative Example 1

[0119] The process of Example 1 was repeated, except that after obtaining the composite chlorine spheres A1, styrene grafting was not performed. Instead, the composite microspheres A1 were directly subjected to quaternization reaction and ion exchange treatment.

[0120] 60.0 g of styrene, 4.5 g of divinylbenzene, and 0.6 g of benzoyl peroxide initiator were placed in a 500 mL three-necked flask and stirred at 60 °C for 1.0 h. Then, 0.7 g of octavinyl POSS was added, and stirring continued for 1 h for prepolymerization. 300 mL of deionized water containing 2.9 g of gelatin was added. The stirring speed was adjusted, and the temperature was gradually increased to 78 °C for 4 h; then increased to 90 °C for 4 h; and finally increased to 98 °C for 5 h. After the reaction was complete, the supernatant was decanted, washed with 80 °C hot water, then washed with cold water, filtered, dried in a vacuum oven at 60 °C, sieved, and composite microspheres with a particle size in the range of 0.35–0.60 mm were collected.

[0121] 40 g of composite microspheres and 180 ml of chloromethyl ether were placed in a 500 ml three-necked flask and allowed to stand at room temperature for 3 hours. Then, stirring was started, and 16 g of zinc chloride was added as a catalyst. The temperature was raised to 60 °C and the reaction was carried out for 4 hours. After chloromethylation was completed, the mixture was cooled to room temperature, the chlorination mother liquor was filtered out, and the mixture was washed repeatedly with methanol. The mixture was then dried in a vacuum oven at 60 °C for 10 hours to obtain composite chlorine spheres (chlorine content 10%).

[0122] Add 40 g of composite chlorine spheres, 70 g of tributylphosphine and 200 ml of acetonitrile to a 500 ml three-necked flask, react at 80 °C for 24 hours, cool to room temperature, filter, and wash successively with ethyl acetate, 0.1 mol / L HCl, deionized water and methanol, and then dry under vacuum at 60 °C for 24 hours to obtain composite quaternary phosphonium microspheres D1.

[0123] In a 1000 ml three-necked flask, 40 g of composite quaternary phosphonium microspheres D1 were added, along with 500 ml of a 0.5 mol / L deionized NaBr aqueous solution. The mixture was stirred at room temperature for 10 hours to induce an ion exchange reaction. The solution was then washed with deionized water until the pH of the washings reached 7. After vacuum drying, the nanocomposite ion exchange resin catalyst Cat-D1 was obtained. [Experimental Example 8] Preparation of cyclic carbonates by addition reaction of epoxides / carbon dioxide.

[0124] The nanocomposite ion exchange resin catalyst Cat-1 prepared in [Example 1] was used in the addition reaction of ethylene oxide and carbon dioxide. The experimental conditions were as follows: Under high-purity nitrogen protection, 50.0 g of ethylene oxide and 2.5 g of catalyst Cat-A1 were added to a 500 mL autoclave, 2.0 MPa of CO2 was introduced, the temperature was raised to 110 °C, and then CO2 was introduced to maintain the reaction pressure at 2.0 MPa. After reacting for 2 hours, the catalyst was removed by filtration, and the conversion rate of ethylene oxide C was measured. EO The selectivity of ethylene carbonate was 99.2%. EC It is 99.6%.

[0125] The addition reaction of alkyl epoxides with carbon dioxide using catalysts obtained in other examples also has the advantages of high conversion of ethylene oxide and high selectivity of ethylene carbonate.

[0126] [Comparative Example 2] Preparation of cyclic carbonates by addition reaction of epoxides / carbon dioxide

[0127] The nanocomposite ion exchange resin catalyst Cat-D1 prepared in [Comparative Example 1] was used in the addition reaction of ethylene oxide and carbon dioxide. The experimental conditions were as follows: Under high-purity nitrogen protection, 50.0 g of ethylene oxide and 2.5 g of catalyst Cat-D1 were added to a 500 mL autoclave, 2.0 MPa of CO2 was introduced, the temperature was raised to 110 °C, and then CO2 was introduced to maintain the reaction pressure at 2.0 MPa. After reacting for 2 hours, the catalyst was removed by filtration, and the conversion rate of ethylene oxide C was measured. EO The selectivity of ethylene carbonate was 98.3%, with a specificity of S. EC It is 99.2%.

[0128] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A quaternary phosphonium salt catalyst for a cycloaddition reaction, which is prepared by grafting a plurality of quaternary phosphonium salt molecular chains represented by formula (I) onto a styrene-based crosslinking copolymer resin containing inorganic nanomaterials as a matrix: ###0001### wherein the inorganic nanomaterials are selected from at least one of carbon nanotubes, graphene, POSS compounds, graphite, and fullerenes. Formula (I) In formula (I), R 1 , R 2 , R 3 , R 4 are each independently selected from one of hydrogen, alkyl, aryl, ester group, R1, R2, R3 are each independently selected from one of alkyl, aryl, n=4-100, X - is an anion, P is phosphorus element; the weight of the styrene crosslinking copolymer resin containing inorganic nanomaterial is 5wt%-50wt% based on 100wt% of the weight of the quaternary phosphonium salt catalyst, the weight of multiple molecular chains of the quaternary phosphonium salt represented by formula (I) is 50wt%-95wt%.

2. The cycloaddition reaction catalyst according to claim 1, characterized in that, In formula (I), R 1 , R 2 , R 3 , R 4 are each independently selected from one of hydrogen, C1-C30 alkyl, C6-C30 aryl, C2-C30 ester, R1, R2, R3 are each independently selected from one of C1-C10 alkyl, C6-C20 aryl, X - is at least one of a halide anion, an organic acid anion.

3. The cycloaddition reaction according to claim 1 or 2, characterized in that, The weight content of the inorganic nanomaterials is 0.1 wt% to 4 wt% based on 100 wt% of the total weight of the styrene-based crosslinking copolymer resin containing inorganic nanomaterials.

4. The cycloaddition reaction catalyst according to claim 3, characterized in that, The styrene-based crosslinking copolymer resin containing inorganic nanomaterials is obtained by mixing components including a styrene-based monomer, a crosslinking agent, inorganic nanomaterials, and an initiator, and then performing copolymerization.

5. The cycloaddition reaction application quaternary phosphonium salt catalyst according to claim 4, characterized in that, The styrene-based monomer is selected from at least one of styrene and derivatives thereof.

6. The cycloaddition reaction application quaternary phosphonium salt catalyst according to claim 5, characterized in that, The styrene-based monomer is selected from at least one of styrene, halogen-substituted styrene, halogen-substituted alkyl styrene, α-methyl styrene, and alkoxy-substituted styrene.

7. The cycloaddition reaction application quaternary phosphonium salt catalyst according to claim 5, characterized in that, The crosslinking agent is selected from at least one of divinylbenzene, divinylbenzene, ethylene glycol dimethacrylate, dipropenylbenzene, and divinylbenzene methyl.

8. The cycloaddition reaction application quaternary phosphonium salt catalyst according to claim 5, characterized in that, The styrene-based crosslinking copolymer resin containing inorganic nanomaterials is sequentially subjected to (1) optional chloromethylation, (2) initiation of polymerization of the styrene-based monomer in the presence of a catalyst and a ligand, and then optional chloromethylation, (3) quaternization, and (4) ion exchange to obtain the quaternary phosphonium salt catalyst for the cycloaddition reaction; in step (2), the molar ratio of the catalyst to the ligand is 1: (1 to 10), the total weight of the catalyst and the ligand to the weight of the product of step (1) is (0.08 to 0.4): 1, and the weight of the styrene-based monomer to the product of step (1) is (1 to 6):

1.

9. A process for the preparation of a cyclic addition reaction quaternary phosphonium salt catalyst for use in a cyclic addition reaction as claimed in any one of claims 1 to 8, said process comprising: The styrene-based crosslinking copolymer resin containing inorganic nanomaterials is obtained by mixing raw materials including a styrene-based monomer, a crosslinking agent, inorganic nanomaterials, and an initiator, and then performing copolymerization.

10. The method of claim 9, wherein, The styrene-based monomer is selected from at least one of styrene and derivatives thereof; and / or, the crosslinking agent is selected from at least one of divinylbenzene, divinylbenzene, ethylene glycol dimethacrylate, dipropenylbenzene, and divinylbenzene methyl; and / or, the initiator is selected from at least one of benzoyl peroxide, azobisisobutyronitrile, azobisisoheptyl nitrile, lauryl peroxide, and cumene hydroperoxide.

11. The method of claim 10, wherein, The styrene-based monomer is selected from at least one of styrene, p-chloromethyl styrene, α-methyl styrene, and alkoxy-substituted styrene.

12. The method of claim 10, wherein, The weight content of the inorganic nanomaterials is 0.1 wt% to 4 wt% based on 100 wt% of the total weight of the raw materials; and / or, the weight content of the styrene monomer is 82 wt% to 95 wt%; and / or, the weight content of the crosslinking agent is 2 wt% to 15 wt%; and / or, the weight content of the initiator is 0.1 wt% to 3 wt%.

13. The preparation method according to claim 10, characterized in that, 14. The method of claim 9, wherein ​ When the halogen-substituted styrene and / or halogen-substituted alkylstyrene is used as the styrene-based monomer to prepare the inorganic nanomaterial-containing styrene-based crosslinking copolymer resin, the step (1) is not performed; or, when other styrene-based monomers except the halogen-substituted styrene and halogen-substituted alkylstyrene are used to prepare the inorganic nanomaterial-containing styrene-based crosslinking copolymer resin, the step (1) is performed; and / or, When the styrene-based monomer in the step (2) is selected from the halogen-substituted styrene and / or halogen-substituted alkylstyrene, the step (3) is not performed after the end of the step (2); or, when the styrene-based monomer in the step (2) is selected from other styrene-based monomers except the halogen-substituted styrene and halogen-substituted alkylstyrene, the step (3) is performed after the end of the step (2).

15. The preparation method according to claim 9, characterized in that, In the step (2), the catalyst is selected from cuprous halide; and / or, the ligand is selected from nitrogen-based ligand.

16. The method of claim 15, wherein, In the step (2), the catalyst is selected from cuprous chloride and / or cuprous bromide; and / or, the ligand is selected from at least one of 2,2'-bipyridine, PMDETA, pyridine imine, DETA, TREN, CYCLAM.

17. The preparation method according to claim 9, characterized in that, In the step (3), the quaternary phosphonium reaction is performed using the P-containing compound shown in formula (II): Formula (II); In formula (II), R1, R2, R3 are each independently selected from one of alkyl group, aromatic group; and / or, the temperature of the quaternary phosphonium reaction is 50-150℃, and the time is 12-36h; and / or, the post-treatment is performed after the quaternary phosphonium reaction.

18. The method of claim 17, wherein, In the step (3), In formula (II), R1, R2, R3 are each independently selected from one of C1-C10 alkyl group, C6-C20 aromatic group; and / or, the post-treatment includes: sequentially using organic solvent I, inorganic acid aqueous solution, water, organic solvent II for washing.

19. The method of claim 17, wherein, In the step (3), the weight ratio of the P-containing compound shown in formula (II) to the product of the step (2) is (0.5-3.5):1; and / or, the organic solvent I is selected from at least one of ethyl acetate, methyl formate, methyl acetate; and / or, the inorganic acid aqueous solution is selected from at least one of hydrochloric acid aqueous solution, sulfuric acid aqueous solution, nitric acid aqueous solution; and / or, the organic solvent II is selected from at least one of methanol, ethanol, propanol.

20. The method of any one of claims 9 to 19, wherein the method further comprises the step of: The ion exchange treatment in the step (4) is performed in a salt-containing aqueous solution. ​ 21. The method of claim 20, wherein, The salt is selected from at least one of halide, sodium formate, potassium formate, magnesium formate, calcium formate, sodium acetate, potassium acetate, magnesium acetate, calcium acetate.

22. The preparation method according to claim 20, characterized in that, The ion exchange treatment is performed for 3-24h.

23. A quaternary phosphonium salt catalyst for the cycloaddition reaction prepared by the preparation method of any one of claims 9-22.

24. Use of the quaternary phosphonium salt catalyst for the cycloaddition reaction of any one of claims 1-8 or the quaternary phosphonium salt catalyst for the cycloaddition reaction prepared by the preparation method of any one of claims 9-22 in the preparation of cyclic carbonate by the cycloaddition reaction of alkylene oxide / carbon dioxide.

25. The use according to claim 24, characterized in that, Catalyst for the cycloaddition reaction.

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