CN118146457A

CN118146457A - Catalyst of cyclic carbonate, preparation method and application thereof

Info

Publication number: CN118146457A
Application number: CN202410180546.3A
Authority: CN
Inventors: 范士敏; 金峰; 陈烽; 鲁江; 曾君; 秦勇; 潘玉杰; 曹勇; 王传伟; 孟凡军; 李赫鑫; 韩京京
Original assignee: Ningbo Conch New Material Technology Co ltd; Anhui Conch Material Technology Co ltd
Current assignee: Ningbo Conch New Material Technology Co ltd; Anhui Conch Material Technology Co ltd
Priority date: 2024-02-18
Filing date: 2024-02-18
Publication date: 2024-06-07

Abstract

The invention provides a catalyst of cyclic carbonate and a preparation method and application thereof, wherein a main catalyst with a comb-shaped molecular structure is polymerized by polyether macromonomer, quaternary ammonium salt monomer and tertiary amine monomer, quaternary ammonium salt group and tertiary amine group are loaded on a polymer main chain, and a side chain is polyether macromonomer with a certain molecular weight, so that the catalyst not only can play a role in catalyzing quaternary ammonium salt, but also has a certain complexing effect on tertiary amine group, hydroxyl group and oxygen atom in ether bond structure, and can stabilize ion pairs of the quaternary ammonium salt catalyst and ensure the catalytic effect of the catalyst. The comb-shaped molecular structure endows the polymer with better electrostatic action and steric hindrance, has better effects of inhibiting material agglomeration in a reaction system and improving the mixing effect of each material. The catalyst promoter is used to provide main catalyst with halogen ion with large ion radius, such as bromine, iodine, etc., and to exchange with chlorine ion in quaternary ammonium salt to form quaternary ammonium bromide salt and quaternary ammonium iodide salt with high catalytic activity.

Description

Catalyst of cyclic carbonate, preparation method and application thereof

Technical Field

The invention belongs to the field of materials, and particularly relates to a catalyst of cyclic carbonate, a preparation method and application thereof.

Background

Global climate and ecosystem variation problems due to carbon dioxide (CO ₂) based greenhouse gas emissions are gaining widespread attention, with global CO ₂ emissions reaching hundreds of billions of tons. The control of the emission of CO ₂, the recovery, fixation, utilization and recycling of the CO ₂, has become a serious concern in countries around the world. Meanwhile, CO ₂ is the most abundant and inexpensive carbon-C1 resource worldwide from a resource standpoint. Therefore, the green utilization technology of CO ₂ is greatly developed, a green high-new fine chemical industry chain is developed, the added value of the product is improved, and the method has important significance.

Cyclic carbonates, especially ethylene/propylene carbonate, are used as basic chemical materials for lithium battery electrolytes, polycarbonates, non-isocyanate polyurethanes, degradable plastics, heterocyclic compounds, dimethyl carbonate, vinylene carbonate, chloroethylene carbonate, fluoroethylene carbonate and other high value-added fine chemicals (Chen Songcong and the like, indirect utilization of carbon dioxide: ethylene carbonate application research progress [ J ], molecular catalysis, 2010,24 (6), 556-568). The current synthetic methods for the synthesis of cyclic carbonates include phosgene, transesterification, chlorohydrin, urea alcoholysis and alkylene oxide and CO ₂ synthesis (Yang Chao, research on the synthesis of ethylene carbonate and its use [ D ], western An: university of Northwest industries, 2010). The direct cycloaddition synthesis method of CO ₂ and alkylene oxide is one of the main methods of industrial mass production and is also a process route which is most in line with the scientific concepts of 'atomic economy' and 'green chemistry'.

The catalyst for synthesizing the cyclic carbonate by directly cycloaddition of CO ₂ and alkylene oxide comprises two main types of homogeneous catalysts and heterogeneous catalysts. The homogeneous catalyst has the characteristics of high catalytic efficiency, mild reaction conditions and the like, and comprises quaternary phosphonium salt, quaternary ammonium salt, ionic liquid, alkali metal salts, organic metal salts and the like (Tan Yana and the like, the research progress [ J ] of ethylene oxide and carbon dioxide synthesis of ethylene carbonate catalyst, the chemical progress, 2017,36 (S1): 241-246.); the heterogeneous catalyst is convenient for separating the catalyst from reaction materials, reduces separation energy consumption and cost, and mainly loads the catalyst with catalytic activity to materials such as silicon dioxide, molecular sieve, zeolite, silicon-based materials, polystyrene resin and the like, or adopts metal oxide with Lewis acid and Lewis base conforming to active sites, and further, derives MOFs catalyst with rich acid and alkali active sites and rich pore channels (Zhang Anyu and the like, research progress of preparing propylene carbonate by CO ₂ catalytic conversion is that of catalyst design, performance and reaction mechanism [ J ]. Chemical engineering progress, 2022,41 (S1): 177-189).

The above catalysts exhibit excellent catalytic activity and selectivity for the addition reaction of CO ₂ and alkylene oxides, however, there are also problems and disadvantages. The existing cyclic carbonate industrialization application is mainly homogeneous catalyst, and the main problem is that the dosage of the homogeneous catalyst is large and the energy consumption for separating the catalyst from the reaction liquid is high. Heterogeneous catalysts are also in the theoretical research stage, and the main problems faced include the following: firstly, the preparation process of the heterogeneous catalyst is complex, and the catalyst loaded by physical adsorption or complexation is easy to be fused into the reaction liquid, so that the catalytic efficiency is reduced; secondly, ethylene carbonate is an organic solvent with excellent performance, resin is adopted as a carrier, and the ethylene carbonate is easy to dissolve in high-temperature reaction liquid, so that the catalyst is damaged in structure and the performance is reduced; again, the processing and shaping problems of the catalyst are prominent by using zeolite, molecular sieve, etc. as the support carrier. Furthermore, the reaction process of CO ₂ and the epoxy compound is a gas-liquid interface reaction in a supercritical state, so that higher requirements are provided for contact and mixing of materials, and the research work of the reported homogeneous or heterogeneous catalyst rarely relates to how to improve the contact and mixing of materials through the modification of the catalyst. The research work reported to date on homogeneous or heterogeneous catalysts rarely involves how to promote the contacting and mixing of vapor-liquid materials by modification of the catalyst or catalytic system.

Based on the above, it is necessary to provide a cyclic carbonate catalyst having high catalytic efficiency, good selectivity and simple material separation.

Disclosure of Invention

The invention aims to provide a catalyst of cyclic carbonate and a preparation method thereof, wherein polyether macromonomer, amide monomer and quaternary ammonium salt monomer are used as comonomers, and a free radical polymerization method is adopted to polymerize the catalyst to obtain a main catalyst. The catalyst is used for preparing the cyclic carbonate, and has the effects of high catalytic efficiency, good selectivity and simple material separation.

The invention also aims to provide an application of the catalyst of the cyclic carbonate, wherein the catalyst of the prepared cyclic carbonate is used as a main catalyst and a cocatalyst which are compounded according to a certain proportion, and is used for preparing the cyclic carbonate.

The specific technical scheme of the invention is as follows:

a catalyst of cyclic carbonate is supported quaternary ammonium salt, and has the following structural formula:

In the structural formula, R is one of H, CH ₃; x is halogen, preferably one of Cl, br and I; d is an integer between 0 and 3, m is a positive integer between 5 and 50, n is an integer between 0 and 10, and a is b, c=1 (2.0 to 4.0) and 2.0 to 10.0.

The invention provides a preparation method of a catalyst of cyclic carbonate, which comprises the following steps:

Taking polyether macromonomer and oxidant as priming materials, adding water to dilute until the mass fraction of the priming materials is 60% as priming solution, adding water to a reducing agent and a chain transfer agent to prepare a dropwise adding material A with the mass fraction of 20%, adding water to a quaternary ammonium salt monomer to prepare a dropwise adding material B with the mass fraction of 50%, and adding water to an amide monomer to prepare a dropwise adding material C with the mass fraction of 60%; and simultaneously dropwise adding the material A, the material B and the material C into the priming material at room temperature and normal pressure, continuing to perform heat preservation reaction after the dropwise adding is finished, and adding water to dilute the aqueous solution to 40% by mass percent after the reaction is finished to obtain the catalyst of the cyclic carbonate.

According to the preparation method, the reaction temperature is room temperature, the reaction pressure is normal pressure, the dropwise adding time of the material A is 3.5h, the dropwise adding time of the material B is 3.0h, and the dropwise adding time of the material C is 3.0h. After the completion of the dropwise addition, the reaction time was kept at 1.0h.

The polyether macromonomer is a polyether macromonomer containing unsaturated double bonds, and the molecular structural formula of the polyether macromonomer is shown as follows:

Wherein R is one of H, CH ₃; d is an integer between 0 and 3, m is a positive integer between 5 and 50, and n is an integer between 0 and 10.

The polyether macromonomer is synthesized by adopting an anionic ring-opening polymerization method, metal sodium is used as a catalyst, unsaturated alcohol containing double bonds is used as a priming solution, metal sodium accounting for 1% -3% of the mass of the unsaturated alcohol is added as the catalyst, after the reaction is completed, the mixture is transferred into a reaction kettle with pressure, nitrogen is replaced for 3 times and pumped to-0.1 MPa again, the temperature is raised to 100 ℃, alkylene oxide is introduced according to a certain rate, the reaction temperature is kept between 100 ℃ and 130 ℃ and the reaction pressure is less than or equal to 0.4MPa, and after the alkylene oxide feeding is finished, the heat preservation reaction is continued for 0.5h, so that the light brown yellow polyether macromonomer with certain viscosity is obtained. Synthetic methods are well known in the art and are not described in detail herein.

Preferably, the polyether macromonomer has the structural formula

Any one or more of the following.

The amide monomer is a tertiary amine monomer containing unsaturated double bonds, preferably: one of N, N-dimethylacrylamide, N-diethylacrylamide, N-diisopropylacrylamide, N-dimethyl (methylacrylamide);

The quaternary ammonium salt monomer is a quaternary ammonium salt containing unsaturated double bonds, preferably: one of allyl trimethyl ammonium chloride, allyl trimethyl ammonium bromide, allyl triethyl ammonium bromide, diallyl dimethyl ammonium chloride, diallyl dimethyl ammonium bromide, (3-acrylamidopropyl) trimethyl ammonium chloride, acryloyloxyethyl trimethyl ammonium chloride, methacryloyloxyethyl trimethyl ammonium chloride;

The molar ratio of the polyether macromonomer to the amide monomer to the quaternary ammonium salt monomer is a, b is c=1 (2.0-4.0) and is 2.0-10.0;

The consumption of the oxidant is (0.5% -2%) of the mass of the polyether macromonomer, and the oxidant is selected from one of hydrogen peroxide, sodium persulfate and ammonium persulfate;

the consumption of the reducing agent is (0.2% -0.5%) of the mass of the polyether macromonomer, and the reducing agent is one of L-ascorbic acid, rongalite and E51;

the use amount of the chain transfer agent is 0.2-1% of the mass of the polyether macromonomer, and the chain transfer agent is one of mercaptoethanol, mercaptopropanol, mercaptoacetic acid, mercaptopropionic acid, sodium hypophosphite and the like.

The invention provides an application of a catalyst of cyclic carbonate, which is used as a main catalyst for catalytic synthesis of the cyclic carbonate.

The specific application method comprises the following steps: mixing a main catalyst, a cocatalyst and cyclic carbonate in a reaction kettle, heating up under nitrogen atmosphere, adding alkylene oxide and carbon dioxide, and reacting.

The mass ratio of the main catalyst to the auxiliary catalyst is (5-10): 1;

the mass ratio of the alkylene oxide to the carbon dioxide is 1: (1.1-2.0);

the total dosage of the main catalyst and the auxiliary catalyst is 1% -5% of the mass of the alkylene oxide;

The dosage of the cyclic carbonate is 10% -20% of the mass of the alkylene oxide; the cyclic carbonate is selected from Ethylene Carbonate (EC) or Propylene Carbonate (PC);

The cocatalyst is metal halogen salt and is soluble metal halogen salt; preferably, one of a metal bromide or a metal iodide;

More preferably, the promoter is selected from one or more of sodium bromide, potassium bromide, zinc bromide, ferrous bromide, ferric bromide, cuprous bromide, cupric bromide, chromium bromide, tin bromide, cobalt bromide, sodium iodide, potassium iodide, zinc iodide, ferrous iodide, ferric iodide, cuprous iodide, cupric iodide, chromium iodide, tin iodide, and cobalt iodide.

The cyclic carbonate is an excellent solvent for carbon dioxide and alkylene oxide, and the addition of the bottoming cyclic carbonate into the reaction kettle can improve the solubility of the carbon dioxide and the alkylene oxide in a liquid phase and promote the contact and reaction of the carbon dioxide (CO ₂ for short) and the alkylene oxide. The types of the bottoming cyclic carbonate are consistent with those of the cyclic carbonate to be synthesized, and the working condition of synthesizing ethylene carbonate (EC for short) is that the EC is used for bottoming; the working condition of synthesizing propylene carbonate (PC for short) is that PC is used for priming.

The purity of the carbon dioxide is more than or equal to 99.9%;

The water content of the alkylene oxide is less than or equal to 1000ppm, the gas phase purity is more than or equal to 99%, and the aldehyde content is less than or equal to 100ppm;

the alkylene oxide is selected from one of Ethylene Oxide (EO) and Propylene Oxide (PO);

the temperature is raised, and alkylene oxide and carbon dioxide are added after the temperature is raised to 110 ℃;

the reaction temperature is 110-150 ℃ and the reaction pressure is 0.1-2.0 MPa; the reaction time is 1.0h;

Preferably, the specific application method comprises the following steps: adding a main catalyst, a cocatalyst and cyclic carbonate into a reaction kettle, sealing the reaction kettle, performing nitrogen replacement for 3 times, heating the reaction kettle to a set temperature, simultaneously introducing metered alkylene oxide and carbon dioxide into the reaction kettle under certain temperature and pressure conditions, continuing to perform heat preservation reaction for a period of time after feeding is finished, cooling to 50 ℃ after the reaction is finished, discharging to obtain a reaction solution of the cyclic carbonate, and sampling for GC test.

The synthesis of the cyclic carbonate has the reaction principle shown as the following formula:

The catalyst of the cyclic carbonate is prepared by taking polyether macromonomer, amide monomer and quaternary ammonium salt monomer as comonomers, an initiating system comprises an oxidant, a reducing agent and a chain transfer agent, and performing water phase free radical polymerization by a free radical polymerization method. In the invention, the polyether macromonomer, the quaternary ammonium salt monomer and the tertiary amine monomer are polymerized to synthesize the main catalyst with a comb-shaped molecular structure, the quaternary ammonium salt group and the tertiary amine group are loaded on a polymer main chain, and the side chain is the polyether macromonomer with a certain molecular weight, so that the catalytic effect of the quaternary ammonium salt can be exerted, and the tertiary amine group, the hydroxyl group and the oxygen atom in the ether bond structure have a certain complexing effect, so that the ion pair of the quaternary ammonium salt catalyst can be stabilized, and the catalytic effect of the catalyst is ensured. Furthermore, the comb-shaped molecular structure endows the polymer with better electrostatic action and steric hindrance, better inhibits material agglomeration in a reaction system, and improves the mixing effect of each material. The main catalyst structure provided by the invention contains alkaline tertiary amine groups, has a good adsorption effect on acidic carbon dioxide gas, promotes the contact and reaction probability of ethylene oxide and carbon dioxide in a liquid phase, and improves the reaction efficiency of the cyclic carbonate. The quaternary ammonium salt is a common homogeneous catalyst, has the characteristics of high catalyst efficiency and good selectivity, can ensure the catalytic efficiency and selectivity by loading the quaternary ammonium salt into a polymer structure, has a high boiling point, and can be separated from the cyclic carbonate by simple distillation. The catalyst promoter is used to provide main catalyst with halogen ion with large ion radius, such as bromine, iodine, etc., and to exchange with chlorine ion in quaternary ammonium salt to form quaternary ammonium bromide salt and quaternary ammonium iodide salt with high catalytic activity. The invention adopts a catalytic system with a main catalyst and a cocatalyst, and realizes high selectivity and yield of the cyclic carbonate in the simplest and economical mode.

Drawings

FIG. 1 is a GC test spectrum of example 2; (the leftmost peak is the acetonitrile solvent peak, the ethylene oxide peak is next to the acetonitrile peak);

FIG. 2 is a GC test spectrum of example 4 (leftmost peak is acetonitrile solvent peak, ethylene oxide peak next to acetonitrile peak).

Detailed Description

The technical scheme of the invention is further described below with reference to the specific embodiments.

The catalyst of the cyclic carbonate prepared by the invention is used as a main catalyst, and the weight average molecular weight, the molecular weight distribution (PDI) and the polymer peak area ratio are measured by adopting a Wyatt technology corporation gel permeation chromatograph. Mobile phase is NaNO ₃ water solution with the concentration of 0.1 mol/L; the flow phase speed is 1ml/min; sample injection amount is 20 μl; sample concentration 0.5% (sample g/mobile phase g); a detector, namely a Shodex RI-71 type differential refraction detector; standard polyethylene glycol GPC standard (Sigma-Aldrich, molecular weight 1010000,478000,263000,118000,44700,18600,6690,1960,628,232).

The reaction solution of the cyclic carbonate is tested by using an Shimadzu 2030 gas chromatograph, the chromatographic column is an Agilent DB-1701 chromatographic column (column length, column inner diameter, coating thickness: 30m, 0.53mm, 0.50 um), and a sample is prepared by using acetonitrile according to a mass ratio of 1:1. The test conditions were: the sample injection amount was 0.4. Mu.l, the split ratio was 20:1, the sample inlet temperature was set at 270 ℃, the detector temperature was set at 290 ℃, and the column oven was set at temperature programmed (initial 100 ℃, hold 2min, 10 ℃ per minute up to 120 ℃, hold 5min at 20 ℃ per minute up to 220 ℃, hold 20min at 20 ℃ per minute up to 240 ℃).

In the examples, all the material amounts were in parts by mass, and not in parts by mass.

Example 1

A preparation method of a catalyst of cyclic carbonate specifically comprises the following steps:

The molar ratio of example 1 was 0.36:0.72:0.72, designed according to the minimum requirements of a: b: c=1:2:2:

Weighing 1 part of polyether macromonomer PEG-1, 0.5 part of hydrogen peroxide, adding water to prepare a priming solution with the mass fraction of 60%, and fully stirring uniformly and completely dissolving. 0.2 part of L-ascorbic acid and 0.3 part of mercaptoethanol are weighed and added with water to prepare a dropwise adding material A with the mass fraction of 20%, 71 parts of N, N-dimethylacrylamide is weighed and added with water to prepare a dropwise adding material C with the mass fraction of 60%, and 98 parts of allyl trimethyl ammonium chloride is added with water to prepare a dropwise adding material B with the mass fraction of 50%. The reaction conditions are room temperature and normal pressure, and simultaneously, the material A, the material B and the material C are dropwise added; the material A and the material B are added dropwise for 3.5h, and the material B and the material C are added dropwise for 3.0h. After the dripping is finished, the heat preservation reaction is continued for 1.0h, water is added to dilute to 40% of aqueous solution by mass fraction, and the main catalyst is obtained and marked as C-1. The weight average molecular weight M _w =5538, the molecular weight distribution pdi=1.92, and the polymer peak area ratio 92.93% were measured by GPC. Wherein the structure and code of the polyether macromonomer PEG-1 used are shown in Table 1.

Catalysts for other cyclic carbonates (procatalysts C-2, C-3, C-4, C-5, C-6, C-7) were prepared in the same manner as in example 1 except that the raw materials and the amounts thereof were specifically used in accordance with tables 1 and 2.

Table 1 polyether macromonomer raw materials and codes used in the examples

TABLE 2 raw material ratio (unit: parts by mass) for synthesizing Main catalyst

The GPC test results of the procatalysts prepared in each example are shown in table 3.

TABLE 3 GPC test data for the preparation of procatalysts for examples

Example 2

The application of the catalyst of the cyclic carbonate is used for the catalytic synthesis of the cyclic carbonate, and specifically comprises the following steps:

10 parts of ethylene carbonate (EC for short) is weighed, 0.93 part of a main catalyst C-1, 0.10 part of a cocatalyst KBr and 0.05 part of NaI are sequentially added into a reaction kettle, and the reaction kettle is sealed and subjected to nitrogen replacement for 3 times. The reaction vessel was warmed to 110 ℃. The feeding amount of ethylene oxide (EO for short) is 100 parts, the feeding amount of carbon dioxide (CO ₂ for short) is 110 parts, the mass feeding rate of CO ₂ is set to be 1.1 times of EO, the reaction temperature is controlled to be 115+/-5 ℃, and the reaction pressure is 2.0MPa (the pressure shortage is supplemented by nitrogen). After the end of the feeding, the reaction is continued for 1.0h at a constant temperature to obtain a light brown yellow ethylene carbonate reaction liquid, and a sample is taken for GC test.

Example 3-example 8

The application of the catalyst of the cyclic carbonate is used for the catalytic synthesis of the cyclic carbonate, and specifically comprises the following steps: the following cyclic carbonates were obtained by the same reaction procedure as in example 2, using the materials shown in Table 4

Table 4 Material ratios (unit: parts by mass) for the Synthesis of cyclic carbonates in examples

The synthesis process parameters and GC test results of each example are shown in table 5.

TABLE 5 Process parameters for the Synthesis of Cyclic carbonates and GC tests for the examples

According to fig. 2, example 4 has other peaks. (other peaks currently cannot be identified as to which compound, once labeled with a known compound).

Comparative example 1

The synthesis of the cyclic carbonate is specifically as follows: 12 parts of propylene carbonate and 3.5 parts of dodecyl trimethyl ammonium bromide serving as a main catalyst are weighed into a reaction kettle, and the reaction kettle is closed and subjected to nitrogen replacement for 3 times. The reaction kettle was warmed to 135 ℃. The feeding amount of propylene oxide (PO for short) is weighed to be 100 parts, the feeding amount of carbon dioxide (CO ₂ for short) is 125 parts, the mass feeding rate of CO ₂ is set to be 1.25 times of EO, the reaction temperature is controlled to be 135+/-5 ℃, and the reaction pressure is 1.5MPa (the pressure shortage part is supplemented by nitrogen). After the end of the feeding, the reaction is continued for 1.0h under heat preservation to obtain light brown yellow propylene carbonate reaction liquid, and GC test is carried out by sampling (percentage of peak area/%): propylene glycol 5.6%, dipropylene glycol 1.35%, propylene oxide 0.74%, propylene carbonate 92.31%. Comparative example 1 has no cocatalyst, no chemical synthesis supported catalyst, and low yield.

A cyclic carbonate of less than 99% indicates poor yields; the content of other byproducts is more than 1%, which indicates that the reaction selectivity is poor, and the influence on the energy consumption and equipment investment of the subsequent rectification and purification is great, in particular to the electronic-grade cyclic carbonate.

Comparative example 2

The synthesis of the cyclic carbonate is specifically as follows: 18 parts of ethylene carbonate, 3 parts of polyethylene glycol (M _n =600) and 4.0 parts of catalyst KI are weighed into a reaction kettle, and the reaction kettle is closed and subjected to nitrogen substitution for 3 times. The reaction vessel was warmed to 160 ℃. The feeding amount of ethylene oxide (EO for short) is 100 parts, the feeding amount of carbon dioxide (CO ₂ for short) is 140 parts, the mass feeding rate of CO ₂ is set to be 1.4 times of EO, the reaction temperature is controlled to be 160+/-5 ℃, and the reaction pressure is 1.8MPa (the pressure shortage is supplemented by nitrogen). After the end of the feeding, the reaction was continued for 1.0h at a constant temperature to obtain a light brown yellow ethylene carbonate reaction solution, and a sample was taken for GC test (peak area percentage/%): ethylene glycol 14.5%, diethylene glycol 12.3%, ethylene oxide 5.7%, ethylene carbonate 67.5%.

Comparative example 2 employs physical compounding of polyethylene glycol with catalyst, no chemical synthesis supported catalyst, no cocatalyst, and over-temperature reaction temperature.

Comparative example 3

15 Parts of ethylene carbonate (EC for short) is weighed, 0.13 part of main catalyst C-4 and 0.02 part of cocatalyst KBr are sequentially added into a reaction kettle, and the reaction kettle is sealed and subjected to nitrogen replacement for 3 times. The reaction kettle was warmed to 140 ℃. The feeding amount of ethylene oxide (EO for short) is 100 parts, the feeding amount of carbon dioxide (CO ₂ for short) is 90 parts, the mass feeding rate of CO ₂ is set to be 0.9 times of EO, the reaction temperature is controlled to be 140+/-5 ℃, and the reaction pressure is 3.0MPa. After the end of the feeding, the reaction was continued for 1.0h at a constant temperature to obtain a light brown yellow ethylene carbonate reaction solution, and a sample was taken for GC test (peak area percentage/%): ethylene glycol 14.2%, diethylene glycol 10.8%, ethylene oxide 15.6%, ethylene carbonate 59.4%.

The main catalyst and the cocatalyst are not used enough, the reaction is over-pressure, the carbon dioxide is used less than the ethylene oxide, and the cyclic carbonate yield is very low.

The above underlined are data that do not meet the requirements of the present invention.

It should be noted that the above-mentioned embodiments are merely some, but not all embodiments of the preferred mode of carrying out the invention. It is evident that all other embodiments obtained by a person skilled in the art without making any inventive effort, based on the above-described embodiments of the invention, shall fall within the scope of protection of the invention.

Claims

1. A catalyst for cyclic carbonates, characterized in that the catalyst for cyclic carbonates has the following structural formula:

In the structural formula, R is one of H, CH ₃; x is halogen; d is an integer between 0 and 3, m is a positive integer between 5 and 50, and n is an integer between 0 and 10.

2. A process for preparing a catalyst for a cyclic carbonate according to claim 1, characterized in that the process comprises: taking polyether macromonomer and oxidant as priming materials, adding water to dilute until the mass fraction of the priming materials is 60% as priming solution, adding water to a reducing agent and a chain transfer agent to prepare a dropwise adding material A with the mass fraction of 20%, adding water to a quaternary ammonium salt monomer to prepare a dropwise adding material B with the mass fraction of 50%, and adding water to an amide monomer to prepare a dropwise adding material C with the mass fraction of 60%; and simultaneously dropwise adding the material A, the material B and the material C into the priming material at room temperature and normal pressure, continuing to perform heat preservation reaction after the dropwise adding is finished, and adding water to dilute the aqueous solution to 40% by mass percent after the reaction is finished to obtain the catalyst of the cyclic carbonate.

3. The preparation method according to claim 2, wherein the molar ratio of the polyether macromonomer, the amide monomer and the quaternary ammonium salt monomer is a:b:c=1 (2.0-4.0) to (2.0-10.0).

4. The preparation method according to claim 2, wherein the polyether macromonomer is a polyether macromonomer containing an unsaturated double bond, and has a molecular structural formula as follows:

5. The method according to claim 2 or 3, wherein the amide-based monomer is a tertiary amine-based monomer having an unsaturated double bond.

6. The method according to claim 2 or 3, wherein the quaternary ammonium salt monomer is a quaternary ammonium salt having an unsaturated double bond.

7. The preparation method according to claim 2, wherein the dropping time of the material A is 3.5 hours, the dropping time of the material B is 3.0 hours, the dropping time of the material C is 3.0 hours, and the reaction time is 1.0 hours after the completion of the dropping.

8. Use of a catalyst of a cyclic carbonate according to claim 1, characterized in that the catalyst of a cyclic carbonate is used as a main catalyst for the catalytic synthesis of a cyclic carbonate.

9. The use according to claim 8, wherein the mass ratio of the main catalyst to the cocatalyst is (5-10): 1, and the cocatalyst is a metal halide salt.

10. The use according to claim 8, wherein the reaction is carried out at a temperature of 110 to 150 ℃ and a reaction pressure of 0.1 to 2.0MPa; the reaction time was kept at 1.0h.