Method for preparing high-performance polyalkylene oxide compound through catalyst modification and application of high-performance polyalkylene oxide compound

Abstract

The invention discloses a method for preparing a high-performance polyalkylene oxide compound through catalyst modification and application of the high-performance polyalkylene oxide compound. An ammonia-calcium catalyst system is modified, an MgAl oxide mesoporous material which can provide an Al active site and can also serve as a carrier is introduced to serve as a cocatalyst, in cooperation with a conventional carrier, the ring-opening polymerization effect of epoxide, especially branched-chain epoxide is improved, full polymerization of branched-chain alkane is achieved, and the high conversion rate of 96% or above is achieved; meanwhile, the molecular weight can be controlled, and the molecular weight can be further increased. Compared with polyoxyethylene, the polyalkylene oxide prepared by the invention has better flexibility and mechanical properties, and can improve the problem that polyoxyethylene is fragile. And meanwhile, the crystallinity of the product is also reduced, and the proportion of an amorphous region is increased. Compared with traditional PEO, in the aspect of solid electrolyte, the crystallinity and the melting point of the PEO are reduced, the ionic conductivity and the mechanical property of the PEO are improved, and the electrochemical performance is improved.

Description

Technical Field

[0001] The present invention belongs to the field of fine chemical engineering, and relates to a method and application for preparing high-performance polyalkylene oxide compounds through catalyst modification. Specifically, it relates to an improved method for preparing an alkylene oxide polymerization catalyst, as well as a method and application for preparing high-performance polyalkylene oxides using this catalyst. Background Art

[0002] So far, the most studied polyalkylene oxide at home and abroad is polyethylene oxide (PEO). PEO is an environmentally friendly material, and its development is supported by the country. The key technology for the synthesis of polyalkylene oxides is the development of efficient catalysts. Starting from the fact that metal oxides and their hydrolyzates can polymerize ethylene oxide to obtain its polymer, through the study of the polymerization mechanism of alkylene oxides, a series of alkylene oxide polymerization catalysts have been developed according to the mechanism of coordination anionic polymerization and ring-opening polymerization into high polymers. Currently, the common polyalkylene oxide catalyst systems mainly refer to polyethylene oxide catalysts, including alkyl metal catalyst systems, alkoxy metal catalyst systems, and alkaline earth metal amide catalyst systems.

[0003] The molecular weight of PEO can vary within 10W - 1000W. When the molecular weight is different, it has other properties such as water retention, lubrication, slow release, thickening, and adhesion, and has a wide range of applications in many fields such as papermaking, medicine, pesticides, daily chemical products, medicine, and industrial engineering. Moreover, in the field of new energy batteries, low-molecular-weight PEO, as a new polymer solid electrolyte, is favored by many scholars and battery companies in lithium battery applications and has achieved certain industrial applications. For example, the Dongfeng-Ganfeng high specific energy solid-state battery E70 demonstration operation vehicle and the Qingneng Institute solid-state lithium battery "Qingneng Ⅰ" both use polymer PEO as a component of the solid electrolyte of the battery. However, the molecular structure of PEO is highly ordered, with a high room temperature crystallinity. The molecular chains are orderly stacked to form spiral channels. Lithium ions conduct through vacancy jumps in the tunnels. Crystal region defects and holes provide power for lithium ion transmission. Limited by the channel diameter, weak molecular chain segments in the crystal region, and the Coulomb force of anions outside the channel, the ion transmission speed is very slow. Therefore, the ionic conductivity of PEO at room temperature is low. At the same time, due to the poor mechanical properties of PEO, the modification of PEO to reduce the crystallinity at room temperature and improve the ionic conductivity is a current research hotspot. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a method for preparing a catalyst, which includes reacting an ammonia-calcium complex, a carrier, and a modifier in the presence of a cocatalyst to obtain the catalyst.

[0005] According to an embodiment of the present invention, the cocatalyst is a MgAl oxide mesoporous material. Preferably, the MgAl oxide mesoporous material is a solid composite containing MgO and Al 2 O 3 and has a porous structure with a pore diameter of 2 - 50 nm.

[0006] According to an embodiment of the present invention, the BET specific surface area of the MgAl oxide mesoporous material can be 80 - 500 m 2 / g, for example 100 - 250 m 2 / g.

[0007] According to an embodiment of the present invention, in the MgAl oxide mesoporous material, the pore volume A of the mesopores (2 - 50 nm) is 0 < A < 0.015 cm 3 / g, for example 0 < A ≤ 0.013 cm 3 / g. Further, the MgAl oxide mesoporous material may also contain macropores (pore diameter greater than 50 nm). Preferably, the pore diameter range of the macropores does not exceed 100 nm, preferably does not exceed 80 nm. Among them, the pore volume B of the macropores is 0 < B < 0.005 cm 3 / g, for example 0 < B ≤ 0.0025 cm 3 / g.

[0008] According to an embodiment of the present invention, the MgAl oxide mesoporous material has an XRD pattern substantially as Figure 1 shown.

[0009] According to an embodiment of the present invention, the preparation method of the MgAl oxide mesoporous material includes: in the presence of a template agent, co-precipitating a solution containing Mg(NO 3 ) 2 , Al(NO 3 ) 3 and the template agent, and obtaining the MgAl oxide mesoporous material after heat-treating the obtained precipitate.

[0010] According to an embodiment of the present invention, the solution contains Mg(NO 3 ) 2 , Al(NO 3 ) 3 , the template agent and water.

[0011] According to an embodiment of the present invention, the solution is also subjected to pH adjustment before co-precipitation. Preferably, the solution containing Mg(NO 3 ) 2 and Al(NO 3 ) 3 is subjected to pH adjustment and then co-precipitated.

[0012] According to an embodiment of the present invention, Mg(NO 3 ) 2 , Al(NO 3 ) 3 , a template agent and water are mixed, and the solution is obtained after stirring. Preferably, the stirring is carried out under heating conditions, for example, the temperature is raised to 40-50 °C, for example, 43-47 °C, and an example thereof can be 45 °C.

[0013] According to an embodiment of the present invention, the solution containing Mg(NO 3 ) 2 and Al(NO 3 ) 3 is adjusted in pH and then undergoes a heating reaction to fully precipitate.

[0014] According to an embodiment of the present invention, the pH of the solution after pH adjustment is above 7, for example, 7.5-10, such as 8-9.

[0015] According to an embodiment of the present invention, the pH adjustment can be achieved using a base. The base is, for example, an inorganic base or an organic base, and is, for example, one or more selected from the following: hydroxides, amides, alcoholates, acetates, carbonates or bicarbonates of alkaline earth metals or alkali metals, such as lithium diisopropylamide, sodium methoxide, sodium ethoxide, potassium tert-butoxide, sodium tert-butoxide, sodium acetate, potassium acetate, calcium acetate, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, potassium bicarbonate, sodium bicarbonate, cesium carbonate or ammonium carbonate; ammonia, such as gaseous NH 3 or ammonia water; amine compounds, such as primary amines, secondary amines or tertiary amines, such as trimethylamine, triethylamine (TEA), tributylamine, N,N-dimethylaniline, N,N-dimethyl-benzylamine, N,N-diisopropyl-ethylamine (DIPEA), pyridine, N-methylpiperidine, N-methylmorpholine, N,N-dimethylaminopyridine, diazabicyclooctane (DABCO), diazabicyclononene (DBN) or diazabicycloundecene (DBU). Preferably, the base is selected from gaseous NH 3 or ammonia water.

[0016] According to an embodiment of the present invention, the heating reaction can be carried out at 40-80 °C, for example, 45-65 °C, for example, 50-60 °C.

[0017] According to an embodiment of the present invention, the time of the heating reaction is not particularly limited as long as the reaction can be completed. For example, the reaction time can be 0.5-24 h, for example, 1-12 h, such as 3-10 h, and examples thereof can be 4 h, 5 h, 6 h, 7 h or 8 h.

[0018] According to an embodiment of the present invention, the precipitate obtained by coprecipitation is heat-treated after washing. The washing can be carried out with water, such as deionized water.

[0019] According to an embodiment of the present invention, the heat treatment includes drying and calcination. Preferably, the temperature of the drying is lower than that of the calcination. For example, the drying is carried out at 80 - 120°C, such as 100°C. The drying time can be 1 - 24 h, such as 10 - 15 h, and an example can be 12 h.

[0020] According to an embodiment of the present invention, the calcination temperature is lower than the melting temperature of the precipitate; for example, the calcination is carried out at 200 - 900°C, such as 400 - 800°C, like 500 - 700°C, for example 600 - 680°C, such as 620 - 680°C. The calcination time can be 1 - 12 h, such as 3 - 10 h, and an example can be 6 h.

[0021] According to an embodiment of the present invention, the template agent can be selected from one or more of the following: sodium dodecylbenzenesulfonate, cetyltrimethylammonium bromide, urea, hexamethyleneimine, diethylamine, tetrabutylammonium bromide, methylcellulose, polyvinylpyrrolidone, glucose, etc.; preferably, it can be selected from sodium dodecylbenzenesulfonate, cetyltrimethylammonium bromide or tetrabutylammonium bromide.

[0022] According to an embodiment of the present invention, Mg(NO 3 ) 2 、Al(NO 3 ) 3 and the molar ratio of the template agent can be 1:(0.1 - 4):(0.5 - 2), for example, the molar ratio is 1:(0.5 - 3):(1 - 1.5), and exemplarily, the molar ratio is 1:1:1.5.

[0023] According to an embodiment of the present invention, the promoter MgAl oxide mesoporous material can also be obtained by calcining a hydrotalcite that meets the specific surface area and the magnesium-aluminum ratio. For example, the hydrotalcite that meets the specific surface area and the magnesium-aluminum ratio is selected from Kyowaad 500 in Japan, Goette hydrotalcite FM300, Sakai Chemical hydrotalcite HT-1 in Japan, etc. Also, for example, the calcination is carried out at 200 - 900°C, such as 400 - 800°C, like 500 - 700°C, for example 600 - 680°C, such as 620 - 680°C. The calcination time can be 1 - 12 h, such as 3 - 10 h, and an example can be 6 h.

[0024] According to an embodiment of the present invention, the ammonia-calcium complex is obtained by reacting liquid ammonia with metallic calcium.

[0025] Preferably, the molar ratio of the liquid ammonia to metallic calcium is 11:1 - 240:1, such as 11:1, 20:1, 50:1, 100:1, 120:1, 150:1, 200:1, 240:1.

[0026] Preferably, the purity of the metallic calcium is greater than 99.5%.

[0027] According to an embodiment of the present invention, the modifier includes epoxyalkane compounds and nitrile compounds.

[0028] Preferably, the epoxyalkane compounds are one or more of ethylene oxide, propylene oxide, methyloxirane, and epoxybutane.

[0029] Preferably, the nitrile compounds are one or more of acetonitrile, propionitrile, and butyronitrile.

[0030] According to an embodiment of the present invention, in the modifier, the mass ratio of the epoxyalkane compounds to the nitrile compounds is (0.1 - 50):1; such as 0.1:1, 1:1, 5:1, 10:1, 20:1, 30:1, 40:1, 50:1.

[0031] Preferably, the mass ratio of the metallic calcium to the modifier is (0.1 - 30):1; such as 0.1:1, 1:1, 5:1, 10:1, 20:1, 30:1.

[0032] According to an embodiment of the present invention, the reaction is carried out in the presence of a solvent. For example, the mass ratio of the solvent to the modifier is (10 - 200):1, such as 10:1, 20:1, 50:1, 80:1, 100:1, 150:1, 200:1.

[0033] According to an embodiment of the present invention, the total mass ratio of the promoter and the carrier to the mass of the metallic calcium is (0.3 - 5.5):1, such as 0.3:1, 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 5.5:1.

[0034] According to an embodiment of the present invention, the mass ratio of the carrier to the promoter is (0.1 - 1):1, such as 0.1:1, 0.2:1, 0.5:1, 0.8:1, 1:1.

[0035] According to an embodiment of the present invention, in order to facilitate the addition of the modifier, the modifier can also be dissolved in a solvent. For example, the solvent is one or a mixture of several of n-hexane, n-heptane, cyclohexane, solvent oil No. 6, solvent oil No. 70, solvent oil No. 90, solvent oil No. 120, solvent oil No. 190, solvent oil No. 200, toluene, and petroleum ether. Preferably, the mass ratio of the solvent to the modifier is (0-40):1; exemplarily 0:1, 2:1, 5:1, 8:1, 10:1, 16.7:1, 20:1, 30:1, 40:1. Preferably, the modifier is added to the reaction system in a dropwise manner. For example, the dropping time is 0.1-2 h, exemplarily 0.1 h, 0.5 h, 1 h, 2 h.

[0036] According to an embodiment of the present invention, the carrier is one or two of hydrophilic nano-silica, hydrophilic fumed silica, nano-aluminum oxide, nano-magnesium chloride, and nano-silicoaluminate molecular sieve.

[0037] According to an embodiment of the present invention, the temperature of the reaction is -80°C to -33.5°C, exemplarily -80°C, -70°C, -60°C, -50°C, -40°C, -33.5°C. Also, for example, the reaction can be carried out under stirring.

[0038] According to an embodiment of the present invention, the preparation method further includes performing a deammoniation treatment on the product obtained from the reaction to volatilize excess liquid ammonia. For example, the deammoniation temperature is -30 to 30°C, exemplarily 20°C; the deammoniation time is 0.5 to 2 h, exemplarily 1 h.

[0039] According to an embodiment of the present invention, the preparation method further includes performing an aging treatment on the product after deammoniation to finally obtain a grayish-white or white slurry-like or powdery catalyst. For example, the aging treatment temperature is 35-150°C, exemplarily 70°C; the aging treatment time is 0.3-5 h, exemplarily 1 h.

[0040] According to an embodiment of the present invention, the entire reaction process is always carried out in an inert gas atmosphere environment to isolate air and water. For example, the inert gas atmosphere is selected from gases that are inert to the reaction, preferably one or several of nitrogen, argon, helium, neon, and krypton.

[0041] According to an embodiment of the present invention, the method for preparing the catalyst includes dissolving metallic calcium in liquid ammonia under inert gas conditions, stirring, adding a promoter and a carrier, stirring, and then adding a modifier. The entire reaction temperature is -80°C to -33.5°C. After the dropping is completed, the reaction continues for 1-2 h, and then deammoniation and aging are carried out to obtain the catalyst.

[0042] The present invention also provides a catalyst prepared by the above method.

[0043] The catalyst of the present invention has regular morphology, relatively uniform size distribution, good dispersion effect, and can exhibit higher catalytic activity.

[0044] The present invention also provides the use of the above catalyst, which is used as a catalyst in the preparation of polyalkylene oxide compounds.

[0045] The present invention also provides a method for preparing polyalkylene oxide compounds: including reacting the above catalyst with an alkylene oxide compound to obtain the polyalkylene oxide compound.

[0046] According to an embodiment of the present invention, the alkylene oxide compound is a mixture of ethylene oxide (EO) and propylene oxide (PO) or butylene oxide (BO), or a mixture of ethylene oxide (EO), propylene oxide, and butylene oxide. Preferably, propylene oxide and butylene oxide can be mixed in any ratio as needed.

[0047] According to an embodiment of the present invention, the addition method of the alkylene oxide compound is block or random polymerization. Considering the product properties, the alkylene oxide is mainly ethylene oxide. Among them, the alkylene oxide added in the block method can be EO+PO, PO+EO, BO+EO, EO+BO, EO+PO / BO mixture, or PO / BO mixture+EO; the alkylene oxide added in the random polymerization method can be EO / PO, EO / BO, or EO / PO / BO.

[0048] According to an embodiment of the present invention, in the alkylene oxide compound, the proportion of EO cannot be lower than 85% (the remaining alkylene oxide compounds can be PO or BO, or a mixture of PO and BO, and their proportion cannot be higher than 15%). The present invention does not make a special limitation on the mixing ratio of propylene oxide and butylene oxide, and they can be mixed in any ratio according to actual needs.

[0049] According to an embodiment of the present invention, the reaction temperature is -10 - 50 °C, for example, -10 °C, 0 °C, 10 °C, 20 °C, 50 °C; the pressure of the reaction ≤ 0.4 MPa, for example, 0.01 MPa, 0.02 MPa, 0.03 MPa, 0.04 MPa; the reaction time is 6 - 40 h; for example, 6 h, 10 h, 15 h, 20 h, 30 h, 40 h.

[0050] According to an embodiment of the present invention, the preparation method further includes drying the obtained product. For example, the drying temperature is 10 - 45 °C, preferably 25 - 35 °C.

[0051] According to an embodiment of the present invention, the dosage of the catalyst is such that the active substance content after deducting the solvent accounts for 0.1-3% of the mass of the alkylene oxide compound, and examples are 0.1%, 0.2%, 0.5%, 1%, 2%, 3%.

[0052] According to an embodiment of the present invention, the preparation method can be carried out in the presence of a solvent. For example, first mix the solvent with the catalyst, then displace it (to evacuate air) under an inert gas atmosphere, and then react with the alkylene oxide compound. Again, the inert gas can be at least one of nitrogen, argon, helium, neon, krypton, etc.; preferably nitrogen. Again, the number of displacements can be 5-8 times.

[0053] According to an embodiment of the present invention, the preparation method can be carried out with stirring.

[0054] According to an embodiment of the present invention, the method for preparing the polyalkylene oxide compound includes adding a catalyst under solvent conditions, displacing with an inert gas, introducing the alkylene oxide compound, stirring and reacting, and after the reaction is completed, filtering and drying to obtain the polyalkylene oxide compound.

[0055] The present invention also provides a polyalkylene oxide compound prepared by the above method.

[0056] According to an embodiment of the present invention, the viscosity-average molecular weight of the polyalkylene oxide compound is 1 million to 10 million, and examples are 1 million, 2 million, 3.1 million, 6.2 million, 10 million, 20 million, 30 million, 41 million, 50 million, 60 million, 71 million, 81 million, 90 million, 100 million. The present invention can achieve the controllable preparation of the molecular weight of the polyalkylene oxide compound.

[0057] According to an embodiment of the present invention, the polyalkylene oxide compound is a block or copolymerized polyalkylene oxide.

[0058] According to an exemplary embodiment of the present invention, the block polyalkylene oxide has a structural general formula shown in Formula I as follows:

[0059]

[0060] Among them, in the formula, R 1 and R 2 are the same or different and are independently H or methyl or ethyl, x is a number from 0 to 25,900, y is a number from 0 to 25,900, and z is a number from 2,300 to 227,300.

[0061] According to an exemplary embodiment of the present invention, the copolymerized polyalkylene oxide has a structural general formula shown in Formula II as follows:

[0062]

[0063] Among them, in the formula, R 3 and R 4 are the same or different and are independently methyl or ethyl. m and n can be in any ratio. m is a number from 0 to 25,900, n is a number from 0 to 25,900, v is a number from 0 to 25,900, and z is a number from 2,300 to 227,300.

[0064] Advantages of the present invention:

[0065] Based on the currently disclosed industrial PEO catalyst system, the present invention modifies the catalyst system by introducing a MgAl oxide mesoporous material that can both provide Al active sites and serve as a carrier as a co-catalyst, and simultaneously cooperates with conventional carriers such as silica or alumina to improve the catalyst activity. And by introducing other alkylene oxides except EO and through methods such as block or copolymerization, the molecular structure of polyethylene oxide (PEO) is modified to synthesize a new polyalkylene oxide compound with a viscosity-average molecular weight between 1 million and 10 million, thereby reducing the crystallinity of PEO and improving the ionic conductivity and mechanical properties of PEO.

[0066] The present invention modifies the ammonia-calcium catalyst system by introducing a MgAl oxide mesoporous material that can both provide Al active sites and serve as a carrier as a co-catalyst, and cooperates with conventional carriers such as silica or alumina to further improve the catalyst activity and enhance the ring-opening polymerization effect of epoxides, especially branched epoxides, so as to achieve a high conversion rate of more than 96% for the full polymerization of branched alkanes. At the same time, it can also achieve controllable molecular weight and further increase the molecular weight. The polyalkylene oxide prepared by the present invention introduces an alkylene oxide with a methyl or ethyl group to increase the flexibility and mechanical properties of the product. At the same time, the present invention combines the reaction efficiency and achieves a better effect by gradually increasing the content ratio of this group substance. Therefore, the product prepared by the present invention has better flexibility and mechanical properties compared with polyethylene oxide, and can improve the problem that polyethylene oxide is prone to brittleness in certain environments. At the same time, it also reduces the crystallinity of the product and increases the proportion of the amorphous region. Moreover, the product prepared by this method has a lower melting point compared with traditional PEO. In terms of solid electrolytes, reducing the crystallinity and melting point of PEO is beneficial to improving the ionic conductivity and mechanical properties of PEO and increasing the electrochemical performance.

[0067] The polyalkylene oxide compound of about 200,000 - 1,000,000 prepared by the present invention has the advantages of relatively low crystallinity, good mechanical properties, and relatively high ionic conductivity compared with polyethylene oxide, and will have broad application prospects in polymer solid electrolytes in the new energy field. Description of the Drawings

[0068] Figure 1 XRD pattern of the MgAl oxide mesoporous material in Example 1.

[0069] Figure 2 Nitrogen adsorption - desorption isotherm of the MgAl oxide mesoporous material in Example 1.

[0070] Figure 3 Pore size distribution diagram of the MgAl oxide mesoporous material in Example 1.

[0071] Figure 4 SEM (field emission scanning electron microscope) image of the catalyst after loading.

[0072] Figure 5 DSC diagram of Macklin and self - made PEO with a molecular weight of 60W.

[0073] Figure 6 Nuclear magnetic resonance comparative structure diagram of Macklin and self - made PEO with a molecular weight of 60W.

[0074] Figure 7 Nuclear magnetic resonance structure diagram of self - made PEO with a molecular weight of 800W. Detailed implementation manners

[0075] The technical solutions of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only for illustrative explanation of the present invention and should not be construed as limiting the protection scope of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0076] Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods.

[0077] In the following examples of the present invention, the XRD pattern was obtained using an X - ray diffractometer (XRD, D / Max 2500PC type). The test conditions were as follows: Cu Kα radiation source, wavelength of 0.15406 nm, tube voltage of 40 kV, tube current of 40 mA, 2θ = 5 - 80°.

[0078] The BET specific surface area and pore volume were measured using a fully automatic specific surface area and pore size analyzer (BET, Autosorb - iQ2 - MP type). The test conditions were as follows: The sample was dried in a nitrogen atmosphere at 150 °C for 1 h. The specific surface area analysis range was above 0.01 m 2 / g, the pore size distribution analysis range was 3 - 200 nm, the specific surface area repeatability (BET method) < 2% CV, the pipeline temperature was 45 ± 0.1 °C, the degassing temperature was 40 - 350 °C; the degassing stable temperature was ± 5 °C.

[0079] The viscosity-average molecular weight was measured according to the national standard "GB / T 1632.1-2008, Determination of the concentration of polymer dilute solution using a capillary viscometer".

[0080] Calculation method of polymerization yield: mass of product / mass of added epoxide * 100%.

[0081] The melting point was measured according to the national standard "GB / T 19466.3-2004 Differential Scanning Calorimetry (DSC) Part 3: Determination of melting and crystallization temperatures and enthalpies";

[0082] The method for measuring the ionic conductivity of the polyepoxide is as follows:

[0083] Dissolve the polyepoxide in a solvent in a glove box, pour the mixed solution into a polytetrafluoroethylene mold. After all the solvent is dried / evaporated, an electrolyte diaphragm of the polyepoxide is obtained. The ionic conductivity of the electrolyte diaphragm is measured by electrochemical impedance spectroscopy (EIS), and the ionic conductivity of the electrolyte is calculated through the formula: σ = D / (R * S), where D represents the diaphragm thickness, R represents the resistance of the blocking cell body, and S represents the effective area of the electrolyte.

[0084] Example 1

[0085] Preparation of catalyst:

[0086] Prepare aqueous solutions of 1 mol / L Mg(NO 3 ) 2 , Al(NO 3 ) 3 , and the template agent sodium dodecylbenzenesulfonate respectively. Take 200 mL, 200 mL, and 300 mL of the above solutions to prepare a mixed solution; stir the mixed solution at 35 °C for 1.5 hours, then heat to 45 °C, slowly add 25% ammonia water to adjust the pH value of the system to 8.5, react at 50 °C for 6 h, filter by suction after sufficient precipitation, transfer the filter cake into deionized water, wash, filter by suction, repeat 3 times, wash until the aqueous phase after filtration is neutral, dry the filter cake at 100 °C for 12 h and then calcine in a muffle furnace at 650 °C for 6 h to obtain the MgAl oxide mesoporous material as the cocatalyst required for PEO synthesis, and use it for the preparation of the catalyst required for PEO synthesis.

[0087] The XRD pattern of the MgAl oxide mesoporous material is as Figure 1 shown. It can be seen from the figure that the material contains a solid complex of MgO and Al 2 O 3 , and the solid complex has a mesoporous structure with a pore size of 2 - 50 nm.

[0088] As Figure 2As shown, the BET specific surface area of the MgAl oxide mesoporous material is 100 - 250 m 2 / g.

[0089] As Figure 3 shown, for the MgAl oxide mesoporous material, the pore volume A of the mesopores (2 - 50 nm) is 0 < A < 0.015 cm 3 / g·nm, the pore diameter of the macropores (pore diameter greater than 50 nm) does not exceed 80 nm, and the pore volume B of the macropores is 0 < B ≤ 0.0025 cm 3 / g·nm.

[0090] The specific steps for catalyst preparation are as follows: Keep the device in an anhydrous and oxygen - free state under a nitrogen atmosphere. Place a 500 - mL four - necked flask in a dry - ice - ethanol low - temperature bath. After the temperature drops to - 50 °C, introduce 100 g of liquid ammonia. While stirring slowly, add 3 g of metallic calcium into the flask to obtain a blue - black ammonia - calcium complex solution. Then, add 2.5 g of the above - prepared MgAl oxide mesoporous material as a promoter and 0.5 g of hydrophilic nano - silica (Cabot M - 5 fumed silica) respectively, and continue stirring for 1 h. Dissolve a modifier composed of 4.5 g of propylene oxide and 1.4 g of acetonitrile in 100 g of n - hexane solvent, and then add it to the above - mentioned ammonia - calcium complex mixed solution, and finish dropping within 1 h, and react for 1 h; Raise the temperature to 0 °C to volatilize the excess liquid ammonia and keep it for 1 h; Raise the reaction temperature to 60 °C for aging treatment for 1 h, and finally obtain a white slurry - like catalyst.

[0091] After drying, the SEM image of the white slurry - like catalyst is as Figure 4 shown. It can be seen from the figure that: the morphology of the catalyst after adding the carrier is relatively uniform, the dispersion is good, it can fully contact with the epoxide, showing a relatively high activity of the catalyst.

[0092] Example 2

[0093] Catalyst preparation:

[0094] Prepare 1 mol / L Mg(NO 3 ) 2 and Al(NO 3 ) 3, An aqueous solution of sodium dodecylbenzenesulfonate. 200 mL, 200 mL, and 300 mL of the above solution were respectively taken to prepare a mixed solution; the mixed solution was stirred at 35 °C for 1.5 hours, then heated to 45 °C, and 25% ammonia water was slowly added dropwise to adjust the pH value of the system to 8.5. The reaction was carried out at 50 °C for 6 h. After sufficient precipitation, filtration was carried out by suction. The filter cake was transferred into deionized water, washed, and filtered by suction repeatedly for 3 times until the aqueous phase after washing was neutral. The filter cake was dried at 100 °C for 12 h and then calcined in a muffle furnace at 650 °C for 6 h to obtain the co-catalyst MgAl oxide mesoporous material required for the synthesis of PEO, which was used for the preparation of the catalyst required for PEO synthesis.

[0095] The specific steps for catalyst preparation are as follows: Keep the device in an anhydrous and oxygen-free state under an argon atmosphere. Put a 500 mL four-necked flask into a dry ice-ethanol low-temperature bath. After the temperature drops to -50 °C, 70 g of liquid ammonia is introduced. Under slow stirring, 2 g of metallic calcium is added to the flask to obtain a blue-black ammonia-calcium complex solution. Then, 1 g of the self-made co-catalyst MgAl oxide mesoporous material and 1 g of the support nano-aluminum oxide (purchased from Aladdin, nano-aluminum oxide A299286) are added, and stirring is continued for 1 h. A modifier composed of 4.0 g of propylene oxide and 1.0 g of acetonitrile is dissolved in 70 g of n-heptane solvent, and then it is added to the above ammonia-calcium complex mixed solution and added dropwise within 0.8 h. The reaction is carried out for 1.5 h; the temperature is raised to 10 °C to volatilize the excess liquid ammonia and kept for 1 h; the reaction temperature is raised to 70 °C for aging treatment for 1 h, and finally a white slurry catalyst is obtained.

[0096] Example 3

[0097] Catalyst preparation:

[0098] A co-catalyst MgAl oxide mesoporous material for PEO synthesis was prepared by calcining commercial hydrotalcite powder (Kyowaad 500) at 600 °C for 4 h, and it was used for the preparation of the catalyst required for PEO synthesis.

[0099] Among them, the MgAl oxide mesoporous material obtained by calcining Kyowaad 500 has a mesoporous structure with a pore diameter of 2 - 50 nm. The BET specific surface area of the MgAl oxide mesoporous material is 100 - 250 m 2 / g. The pore volume A of the mesopores (2 - 50 nm) in the MgAl oxide mesoporous material is 0 < A < 0.015 cm 3 / g·nm, the pore diameter of the macropores (pore diameter greater than 50 nm) does not exceed 80 nm, and the pore volume B of the macropores is 0 < B ≤ 0.0025 cm 3 / g·nm.

[0100] The specific steps for catalyst preparation are as follows: Keep the device in an anhydrous and oxygen-free state under a nitrogen atmosphere. Place a 500 mL four-necked flask in a dry ice-ethanol low-temperature bath. After the temperature drops to -50 °C, introduce 100 g of liquid ammonia. While stirring slowly, add 3 g of metallic calcium into the flask to obtain a blue-black ammonia-calcium complex solution. Then add 2.5 g of the self-made promoter MgAl oxide mesoporous material and 0.5 g of hydrophilic nano-silica (purchased from Cabot M-5 fumed silica), and continue stirring for 1 h. Add a modifier composed of 4.5 g of propylene oxide and 1.4 g of acetonitrile (without adding a solvent) to the above ammonia-calcium complex mixed solution, and finish dropping within 1 h, and react for 1 h; Raise the temperature to 0 °C to volatilize the excess liquid ammonia, and keep it for 1 h; Raise the reaction temperature to 60 °C for aging treatment for 1 h, and finally obtain a white powder catalyst.

[0101] Example 4

[0102] Catalyst preparation:

[0103] A promoter MgAl oxide mesoporous material for PEO synthesis was prepared by calcining commercial hydrotalcite FM300 at 600 °C for 4 h for the preparation of the catalyst required for PEO synthesis.

[0104] The MgAl oxide mesoporous material obtained by calcining FM300 has a mesoporous structure with a pore diameter of 2 - 50 nm. The BET specific surface area of the MgAl oxide mesoporous material is 100 - 250 m 2 / g. The pore volume A of the mesopores (2 - 50 nm) in the MgAl oxide mesoporous material is 0 < A < 0.015 cm 3 / g·nm, the pore diameter of the macropores (pore diameter greater than 50 nm) does not exceed 80 nm, and the pore volume B of the macropores is 0 < B ≤ 0.0025 cm 3 / g·nm.

[0105] The specific steps for catalyst preparation are as follows: Keep the device in an anhydrous and oxygen-free state under a nitrogen atmosphere. Place a 500 mL four-necked flask in a dry ice-ethanol low-temperature bath. After the temperature drops to -50 °C, introduce 50 g of liquid ammonia. While stirring slowly, add 2 g of metallic calcium into the flask to obtain a blue-black ammonia-calcium complex solution. Then add 5 g of the self-made promoter MgAl oxide mesoporous material and 1 g of fumed nano-silica (Evonik Degussa fumed nano-silica A200) respectively, and continue stirring for 1 h. Add a modifier composed of 5.0 g of propylene oxide and 1.0 g of acetonitrile to 100 g of solvent oil No. 120, and then add it to the above ammonia-calcium complex mixed solution, and finish dropping within 0.2 h, and react for 1.5 h; Raise the temperature to 20 °C to volatilize the excess liquid ammonia, and keep it for 1 h; Raise the reaction temperature to 70 °C for aging treatment for 1 h, and finally obtain a white slurry catalyst.

[0106] Example 5

[0107] Preparation of low molecular weight polyalkylene oxide compound (using the catalyst of Example 1):

[0108] The solid content of the slurried catalyst in Example 1 above was tested to be 12.4% (tested according to the method of "HG / T 4266-2017 Determination method for solid content of textile dyeing and finishing auxiliaries"). For the convenience of calculation in the present invention, the solid content is regarded as the active substance. The active substance of the catalyst accounts for 3% of the epoxy compound. That is, 26.61 g of the slurried catalyst was added to a 2 L reaction kettle with mechanical stirring and good airtightness. Then, 300 g of n-hexane solvent was added to the reaction kettle. The reaction kettle was purged with argon 5 times. 10 g of propylene oxide was added, and the pressure was 0.03 MPa. The polymerization reaction was carried out at 20 °C for 5 h. Then, 100 g of ethylene oxide was introduced, and the polymerization reaction was carried out at 20 °C and a pressure of 0.22 MPa for 20 h. After the reaction was completed, the product obtained was filtered at room temperature and then dried at 30 °C until the mass did not change, obtaining a polyepoxide compound with the following structural formula:

[0109] where x = 971.8 and y = 12810.

[0110] The polyepoxide compound prepared in this example is white powdery particles with uniform particle size. The viscosity-average molecular weight of the synthesized polyalkylene oxide compound is 620,000, and the polymerization yield is 99.8%. Compared with the commercially available (Macklin reagent grade) PEO product with a molecular weight of about 600,000, this product has a higher degree of branching in structure and stronger ion transport ability, and thus exhibits advantages such as low melting point and high ionic conductivity. The specific values are shown in Table 1 below.

[0111] Figure 5 DSC diagrams of Macklin reagent grade PEO and the self-made 600,000 molecular weight PEO in this example. Figure 6 Nuclear magnetic resonance comparison structural diagrams of Macklin reagent grade PEO and the self-made 600,000 molecular weight PEO in this example. From Figure 6 it can be seen that the characteristic peak of PO appears in the nuclear magnetic resonance diagram, indicating that PO has been successfully added to the PEO of the present invention. At the same time, from Figure 5 it can be seen that the melting point of the PEO product obtained by adding PO is lower than that of the product obtained without adding PO, and the crystallinity of the product is reduced, thereby improving the ionic conductivity of the product.

[0112] Table 1

[0113] Sample Molecular weight Ionic conductivity Melting point Maclean 60W <![CDATA[1.11x10 -6 s.cm -1 > 68.97℃ Self-made in Example 5 62W <![CDATA[4.32x10 -6 s.cm -1 > 65.18℃

[0114] Example 6

[0115] Preparation of low molecular weight polyalkylene oxide compound: (using the catalyst of Example 4):

[0116] The solid content of the slurried catalyst in Example 4 above was tested to be 13.1%. For the convenience of calculation in the present invention, the solid content is regarded as the active substance. The active substance of the catalyst accounts for 1.71% of the epoxy compound. That is, 15.27 g of the slurried catalyst is added to a 2 L reaction kettle with good airtightness and mechanical stirring. Then, 250 g of No. 120 solvent oil is added to the reaction kettle, and it is replaced with argon 6 times. A mixed liquid of 10 g of propylene oxide and 7 g of butylene oxide is added, with a pressure of 0.08 MPa. The polymerization reaction is carried out at 10 °C for 13 h, and then 100 g of ethylene oxide is introduced. The polymerization reaction is carried out at 30 °C and a pressure of 0.22 MPa for 23 h. After the reaction is completed, the product obtained is filtered at room temperature and then dried at 20 °C until the mass does not change, obtaining a polyepoxide compound with the following structure:

[0117] where x = 457.3, y = 257.9, z = 6028.5.

[0118] The polyepoxide compound prepared in this example is white powdery particles with uniform particle size. The viscosity-average molecular weight of the synthesized polyalkylene oxide compound is 310,000, the polymerization yield is 96.8%, the melting point is measured to be 63.25 °C, and the ionic conductivity is 3.31x10 -6 s.cm -1 .

[0119] Example 7

[0120] Preparation of medium molecular weight polyalkylene oxide compound: (using the catalyst of Example 4):

[0121] The solid content of the slurried catalyst in Example 4 above was tested to be 12.1%. For the convenience of calculation in the present invention, the solid content is regarded as the active substance. The active substance of the catalyst accounts for 0.9% of the epoxy compound. That is, 8.7 g of the slurried catalyst is added to a 2 L reaction kettle with good airtightness and mechanical stirring. Then, 250 g of No. 120 solvent oil is added to the reaction kettle, and it is replaced with nitrogen 7 times. 100 g of ethylene oxide is introduced, with a pressure of 0.20 MPa. The polymerization reaction is carried out at 10 °C for 5 h. When the pressure drops to 0.14 MPa, a mixed liquid of 10 g of propylene oxide and 7 g of butylene oxide is added, with a pressure of 0.18 MPa. The polymerization reaction is carried out at 30 °C for 23 h. After the reaction is completed, the product obtained is filtered at room temperature and then dried at 20 °C until the mass does not change, obtaining a polyepoxide compound with the following structure:

[0122] where x = 79642.6, y = 6041.9, z = 3406.9.

[0123] The polyepoxide prepared in this example is white powdery particles with uniform particle size. The viscosity-average molecular weight of the synthesized polyalkylene oxide compound is 4.1 million, and the polymerization yield is 98.8%.

[0124] Example 8

[0125] Preparation of high molecular weight polyalkylene oxide compound (using the catalyst of Example 2):

[0126] The solid content of the slurried catalyst in Example 2 above was tested to be 12.4%, and the catalyst active substance accounted for 0.3% of the epoxide. That is, 2.42 g of the slurried catalyst was added to a well-sealed 2 L reaction kettle with mechanical stirring. Then, 500 g of n-hexane solvent was added to the reaction kettle, and nitrogen replacement was carried out 7 times. 15 g of epoxybutane was added, and the pressure was 0.04 MPa. The polymerization reaction was carried out at 20 °C for 5 h, and then 85 g of ethylene oxide was introduced. The polymerization reaction was carried out at 20 °C and a pressure of 0.21 MPa for 20 h. After the reaction was completed, the product obtained was filtered at room temperature, and then dried at 25 °C until the mass did not change, obtaining a polyepoxide with the following structure:

[0127] Where x = 14791.7 and y = 137159.1.

[0128] The polyepoxide prepared in this example is white powdery particles with uniform particle size. The viscosity-average molecular weight of the synthesized polyalkylene oxide compound is 7.1 million, and the polymerization yield is 99%.

[0129] Example 9

[0130] Preparation of high molecular weight polyalkylene oxide compound (using the catalyst of Example 3):

[0131] 0.4 g of the powder catalyst of Example 3 above was added to a well-sealed 2 L reaction kettle with mechanical stirring. Then, 300 g of n-heptane solvent was added to the reaction kettle, and nitrogen replacement was carried out 8 times. 15 g of propylene oxide was added, and the pressure was 0.05 MPa. The polymerization reaction was carried out at 25 °C for 5 h, and finally 100 g of ethylene oxide was introduced. The polymerization reaction was carried out at 25 °C and a pressure of 0.22 MPa for 22 h. After the reaction was completed, the product obtained was filtered at room temperature, and then dried at 35 °C until the mass did not change, obtaining a polyepoxide with the following structure:

[0132] Where x = 18215.9 and y = 160079.

[0133] The polyepoxide prepared in this example is white powdery particles with uniform particle size. The viscosity-average molecular weight of the synthesized polyalkylene oxide compound is 8.1 million, and the polymerization yield is 98%.

[0134] The NMR characterization result diagram of the polyepoxide prepared in this example is shown in Figure 7 , and it can be seen from Figure 7 that by this method, propylene oxide can be effectively added to change the structure of the original PEO, so as to realize the structural modification of PEO.

[0135] Comparative Example 1: Prepare low-molecular-weight PEO without using a cocatalyst.

[0136] Under a nitrogen atmosphere, keep the device in an anhydrous and anaerobic state. Put a 500 mL four-necked flask into a dry ice-ethanol low-temperature bath. After the temperature drops to -50 °C, introduce 100 g of liquid ammonia. Under slow stirring, add 3 g of metallic calcium to the flask to obtain a blue-black ammonia-calcium complex solution, then add 3 g of hydrophilic nano-silica (CAB-O-SIL M-5 fumed silica purchased from Cabot (China) Investment Co., Ltd.), and continue stirring for 1 h. Dissolve the modifier composed of 4.5 g of propylene oxide and 1.4 g of acetonitrile in 100 g of n-hexane solvent, and then add it to the above ammonia-calcium complex. Finish dropping within 1 h and react for 1 h; raise the temperature to 0 °C to volatilize the excess liquid ammonia and keep it for 1 h; raise the reaction temperature to 60 °C for aging treatment for 1 h, and finally obtain a white slurry catalyst.

[0137] The solid content of the slurry catalyst in Comparative Example 1 was tested to be 12.7%. For the convenience of calculation in the present invention, the solid content is regarded as the active substance. The active substance of the catalyst accounts for 3% of the epoxide. That is, 25.98 g of the slurry catalyst should be added to a 2 L reaction kettle with mechanical stirring and good airtightness. Then add 300 g of n-hexane solvent to the reaction kettle, replace it with argon 5 times, add 10 g of propylene oxide, with a pressure of 0.03 MPa, and carry out a polymerization reaction at 20 °C for 5 h. Then introduce 100 g of ethylene oxide, and carry out a polymerization reaction at 20 °C and a pressure of 0.22 MPa for 20 h. After the reaction is completed, filter the obtained product at room temperature, and then dry it at 30 °C until the mass does not change to obtain a polyepoxide, and the structure is as follows:

[0138] where x = 893.4 and y = 11776.9.

[0139] The polyepoxide prepared in this comparative example is white powdery particles with uniform particle size. The viscosity-average molecular weight of the synthesized polyalkylene oxide compound is 570,000, the polymerization yield is 88.9%, the measured melting point is 68.15 °C, and the ionic conductivity is 1.09x10 -6 s.cm-1 This indicates that: without the addition of a cocatalyst, while the molecular weight of the prepared polyalkylene oxide compound decreases, the yield and ionic conductivity also decrease significantly.

[0140] Comparative Example 2: Preparation of high molecular weight PEO without using a cocatalyst.

[0141] The solid content of the slurried catalyst in the above Comparative Example 1 was tested to be 12.7%, and the catalyst active substance accounted for 0.3% of the epoxy compound. That is, 2.36 g of the slurried catalyst was added to a 2 L reaction kettle with good airtightness and mechanical stirring. Then, 500 g of n - hexane solvent was added to the reaction kettle, and nitrogen replacement was carried out 7 times. 15 g of epoxybutane was added, with a pressure of 0.04 MPa, and the polymerization reaction was carried out at 20 °C for 5 h. Then, 85 g of ethylene oxide was introduced, and the polymerization reaction was carried out at 20 °C and a pressure of 0.21 MPa for 20 h. After the reaction was completed, the obtained product was filtered at room temperature and then dried at 25 °C until the mass did not change, obtaining a polyepoxide compound with the following structure:

[0142] where x = 12708.3 and y = 117840.9.

[0143] The polyepoxide compound prepared in this comparative example was white powdery particles with uniform particle size. The viscosity - average molecular weight of the synthesized polyalkylene oxide compound was 6.1 million, and the polymerization yield was 84%. This indicates that: without the addition of a cocatalyst, while the molecular weight of the prepared polyalkylene oxide compound decreases, the yield also decreases significantly.

[0144] The above describes the embodiments of the present invention. However, the present invention is not limited to the above - mentioned embodiments. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a catalyst, characterized in that: The method comprises reacting an ammonia calcium complex, a carrier and a modifier in the presence of a co-catalyst to obtain the catalyst.

2. The preparation method according to claim 1, characterized in that The promoter is a MgAl oxide mesoporous material. Preferably, the MgAl oxide mesoporous material is a solid composite comprising MgO and Al2O3, wherein the solid composite has a porous structure with a pore size of 2-50 nm. Preferably, the BET specific surface area of ​​the MgAl oxide mesoporous material can be 80-500 m 2 / g, for example 100-250m 2 / g. Preferably, in the MgAl oxide mesoporous material, the pore volume A of the mesopores (2-50 nm) is 0 <A<0.015cm 3 / g, for example 0 <A≤0.013cm 3 / g. Preferably, the MgAl oxide mesoporous material may also contain macropores (pore diameter greater than 50 nm). Preferably, the pore diameter range of the macropores does not exceed 100 nm, and preferably does not exceed 80 nm. Preferably, the pore volume B of the macropores is 0 <B<0.005cm 3 / g, for example 0 <B≤0.0025cm 3 / g. Preferably, the preparation method of the MgAl oxide mesoporous material comprises: in the presence of a template, co-precipitating a solution containing Mg(NO3)2, Al(NO3)3 and a template, and obtaining the MgAl oxide mesoporous material after heat treatment of the obtained precipitate. Preferably, the solution comprises Mg(NO3)2, Al(NO3)3, a template and water. Preferably, the solution is further pH-adjusted before co-precipitation. Preferably, the solution containing Mg(NO3)2 and Al(NO3)3 is co-precipitated after pH adjustment. Preferably, Mg(NO3)2, Al(NO3)3, template and water are mixed and stirred to obtain the solution. Preferably, the stirring is carried out under heating conditions, for example, the temperature is increased to 40-50°C, for example 43-47°C. Preferably, the pH of the solution after pH adjustment is above 7, for example, 7.5-10, such as 8-9. Preferably, the pH adjustment can be achieved using a base. The base is, for example, an inorganic base or an organic base, for example, one or more selected from the following: hydroxides, amides, alcoholates, acetates, carbonates or bicarbonates of alkaline earth metals or alkali metals, such as lithium diisopropylamide, sodium methoxide, sodium ethoxide, potassium tert-butoxide, sodium tert-butoxide, sodium acetate, potassium acetate, calcium acetate, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, potassium bicarbonate, sodium bicarbonate, cesium carbonate or ammonium carbonate; ammonia, such as gaseous NH3 or aqueous ammonia; an amine compound, such as a primary amine, a secondary amine or a tertiary amine, such as trimethylamine, triethylamine (TEA), tributylamine, N,N-dimethylaniline, N,N-dimethyl-benzylamine, N,N-diisopropyl-ethylamine (DIPEA), pyridine, N-methylpiperidine, N-methylmorpholine, N,N-dimethylaminopyridine, diazabicyclooctane (DABCO), diazabicyclononene (DBN) or diazabicycloundecene (DBU). Preferably, the heating reaction may be carried out at 40-80°C, such as 45-65°C, such as 50-60°C. Preferably, the precipitate obtained by coprecipitation is washed and then heat-treated. Preferably, the heat treatment includes drying and calcining. Preferably, the drying temperature is lower than the calcining temperature. For example, the drying is performed at 80-120° C., such as 100° C. The drying time may be 1-24 hours, such as 10-15 hours. Preferably, the calcination temperature is lower than the melting temperature of the precipitate; for example, the calcination is carried out at 200-900° C., such as 400-800° C., such as 500-700° C., such as 600-680° C., such as 620-680° C. The calcination time may be 1-12 h, such as 3-10 h. Preferably, the template agent can be selected from one or more of the following: sodium dodecylbenzene sulfonate, hexadecyltrimethylammonium bromide, urea, hexamethyleneimine, diethylamine, tetrabutylammonium bromide, methylcellulose, polyvinylpyrrolidone and glucose, etc.; preferably, it can be selected from sodium dodecylbenzene sulfonate, hexadecyltrimethylammonium bromide or tetrabutylammonium bromide. Preferably, the molar ratio of Mg(NO3)2, Al(NO3)3 and the template can be 1:(0.1-4):(0.5-2), for example, the molar ratio is 1:(0.5-3):(1-1.5). Preferably, the co-catalyst MgAl oxide mesoporous material can also be obtained by calcining a hydrotalcite that meets the specific surface area and magnesium-aluminum ratio. For example, the hydrotalcite that meets the specific surface area and magnesium-aluminum ratio is selected from Japan's Kyowaad 500, Gote hydrotalcite FM300, Japan Sakai Chemical hydrotalcite HT-1, etc. For another example, the calcination is carried out at 200-900°C, such as 400-800°C, such as 500-700°C, such as 600-680°C, such as 620-680°C. The calcination time can be 1-12h, such as 3-10h.

3. The preparation method according to claim 1 or 2, characterized in that: The ammonia calcium complex is obtained by reacting liquid ammonia with metallic calcium. Preferably, the molar ratio of the liquid ammonia to metallic calcium is 11:1-240:

1. Preferably, the modifier comprises an alkylene oxide compound and a nitrile compound. Preferably, the alkylene oxide compound is one or more of ethylene oxide, propylene oxide, methylpropylene oxide and butylene oxide. Preferably, the nitrile compound is one or more of acetonitrile, propionitrile and butyronitrile. Preferably, in the modifier, the mass ratio of the alkylene oxide compound to the nitrile compound is (0.1-50):

1. Preferably, the mass ratio of the metallic calcium to the modifier is (0.1-30):

1. Preferably, the reaction is carried out in the presence of a solvent. For example, the mass ratio of the solvent to the modifier is (10-200):

1. Preferably, the mass ratio of the total mass of the co-catalyst and the carrier to the mass of metallic calcium is (0.3-5.5):

1. Preferably, the mass ratio of the carrier to the co-catalyst is (0.1-1):

1. Preferably, the modifier can also be dissolved in a solvent. For example, the solvent is one or a mixture of n-hexane, n-heptane, cyclohexane, No. 6 solvent oil, No. 70 solvent oil, No. 90 solvent oil, No. 120 solvent oil, No. 190 solvent oil, No. 200 solvent oil, toluene and petroleum ether. Preferably, the mass ratio of the solvent to the modifier is (0-40):

1.

4. The preparation method according to any one of claims 1 to 3, characterized in that: The carrier is one or two of hydrophilic nano silicon dioxide, hydrophilic gas phase silicon dioxide, nano aluminum oxide, nano magnesium chloride and nano silicon aluminum molecular sieve. Preferably, the reaction temperature is -80°C to -33.5°C. Preferably, the preparation method further comprises deamination of the product obtained by the reaction to volatilize excess liquid ammonia. For example, the deamination temperature is -30 to 30°C and the deamination time is 0.5 to 2 hours.

5. The catalyst prepared by the preparation method according to any one of claims 1 to 4.

6. Use of the catalyst according to claim 5, which is used as a catalyst in the preparation of polyalkylene oxide compounds.

7. A method for preparing a polyalkylene oxide compound, characterized in that: The method comprises reacting the catalyst according to claim 5 with an alkylene oxide compound to obtain the polyalkylene oxide compound.

8. The preparation method according to claim 7, characterized in that: The alkylene oxide compound is a mixture of ethylene oxide (EO) and propylene oxide (PO) or butylene oxide (BO) or a mixture of ethylene oxide (EO), propylene oxide and butylene oxide. Preferably, the alkylene oxide compound is added in a block or mixed polymerization manner. Considering the product properties, the alkylene oxide is mainly ethylene oxide. Among them, the alkylene oxide added in a block manner can be EO+PO, PO+EO, BO+EO, EO+BO, EO+PO / BO mixture or PO / BO mixture + EO; the alkylene oxide added in a mixed polymerization manner can be EO / PO, EO / BO or EO / PO / BO. Preferably, in the alkylene oxide compound, the proportion of EO cannot be less than 85%. Preferably, the reaction temperature is -10-50°C; the reaction pressure is ≤0.4MPa; and the reaction time is 6-40h.

9. The preparation method according to claim 7 or 8, characterized in that: The preparation method of the polyalkylene oxide compound comprises adding a catalyst under solvent conditions, replacing with an inert gas, introducing an alkylene oxide compound, stirring for reaction, filtering and drying after the reaction is completed to obtain the polyalkylene oxide compound.

10. The polyalkylene oxide compound prepared by the preparation method according to any one of claims 7 to 9. Preferably, the viscosity average molecular weight of the polyalkylene oxide compound is 100,000-10000,000. Preferably, the polyalkylene oxide compound is a block or mixed polyalkylene oxide. Preferably, the block polyalkylene oxide has a general structural formula as shown in Formula I below: in, In the formula, R1 and R2 are the same or different, and are independently H or methyl or ethyl, x is a number between 0 and 25,900, y is a number between 0 and 25,900, and z is a number between 0.23 and 227,300. Preferably, the mixed polyalkylene oxide has a general structural formula as shown in Formula II below: Among them, R3 and R4 are the same or different, and are independently methyl or ethyl, m and n can be in any proportion, m is a number between 0 and 25,900, n is a number between 0 and 25,900, v is a number between 0 and 25,900, and z is a number between 2,300 and 227,300.

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