Oil-soluble polyether modular synthesis process based on concerted catalysis

Abstract

The invention discloses an oil-soluble polyether modular synthesis process based on concerted catalysis. The synthesis process comprises the following steps: S1, dispersing a DMC catalyst in a graphene oxide solution to obtain a main catalyst; s2, low-carbon alcohol and epoxide are subjected to polyether first-stage synthesis treatment under the action of a main catalyst; and S3, continuously adding 1-methylimidazole, the graphene oxide solution and epoxide to carry out polyether stage II synthesis treatment. And S4, continuing to add the polyol, and carrying out stage III synthesis treatment on the polyether under the action of the Lewis acid catalyst to obtain a polyether product. According to the invention, a three-stage modular reaction system is established, low-component polyether is synthesized by using the stage I, the ratio of alkylene oxide in a polyether molecular structure is increased by using the stage II, and finally hydroxyl modification is performed on the tail end of a polyether chain through the stage III, so that the molecular weight, molecular weight distribution and oil solubility of polyether can be flexibly adjusted according to application requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical catalysis, and in particular to a modular synthesis process of oil-soluble polyether based on synergistic catalysis. Background Art

[0002] Oil-soluble polyethers have important applications in industrial lubricants, surfactants, high-temperature lubricants, and industrial cleaning agents. Existing technologies mostly use ring-opening polymerization of low-carbon alcohols (such as methanol and ethanol) with epoxides (such as ethylene oxide and propylene oxide) to prepare oil-soluble polyethers. However, current synthesis methods for oil-soluble polyethers still face the following technical bottlenecks:

[0003] 1. Molecular weight and performance are not adjustable: Existing methods usually complete a single polymerization reaction with a fixed ratio, making it difficult to flexibly adjust the molecular weight, molecular weight distribution, and oil solubility of the polyether according to application requirements;

[0004] 2. Side reactions and environmental pollution: Traditional catalyst systems, such as metal catalysts, are prone to side reactions in the reaction of low-carbon alcohols with epoxides, resulting in reduced polymerization efficiency. Furthermore, metal residues limit the use of polyethers in high-end applications such as cosmetics and food-grade lubricants.

[0005] 3. Insufficient thermal stability: Some oil-soluble polyether products are easily degraded under high temperature conditions, which limits their further development in the fields of high-temperature lubricants and industrial cleaning agents. Summary of the Invention

[0006] The object of the present invention is to provide a modular synthesis process for oil-soluble polyethers based on synergistic catalysis to overcome the shortcomings of the prior art described above.

[0007] The modular synthesis process of oil-soluble polyether based on synergistic catalysis comprises the following steps:

[0008] S1: dispersing the DMC catalyst in the graphene oxide solution to obtain the main catalyst;

[0009] S2 low carbon alcohol and epoxide, under the action of main catalyst, carry out the first stage synthesis treatment of polyether;

[0010] S3 continues to add 1-methylimidazole, graphene oxide solution and epoxide to carry out the second stage synthesis of polyether;

[0011] In S4, polyol is continuously added to carry out the three-stage synthesis of polyether under the action of Lewis acid catalyst to obtain a polyether product.

[0012] As a further improvement of the above solution, the DMC catalyst is cobalt zinc cyanide crystals, and the crystal size is 20 to 50 nm.

[0013] As a further improvement to the above solution, the graphene oxide content in the graphene oxide solution is 1% to 2% of the DMC catalyst. In the present invention, the graphene oxide improves the dispersibility of the DMC catalyst in the solution during the first stage reaction, thereby enhancing the uniformity and stability of the initiation reaction for polyether synthesis.

[0014] As a further improvement of the above scheme, the method for preparing cobalt zinc cyanide crystals has the following specific operations:

[0015] S11: dissolving a cobalt salt and a zinc salt in water in a ratio of 1:2 to 3 to obtain a salt solution;

[0016] S12 continues to dropwise add triethanolamine to the salt solution to form a precursor through hydrothermal treatment;

[0017] After S13 filtering and washing, the precipitate is retained and cyclohexanone is added to react, and then separated and dried to obtain cobalt zinc cyanide crystals.

[0018] As a further improvement to the above scheme, the amount of triethanolamine added is 2% to 4% of the total amount of the cobalt salt and the zinc salt. In the present invention, triethanolamine is added for surface modification to improve the compatibility of the catalyst with low-carbon alcohols and epoxides, thereby achieving the effect of improving the initiation ability of the stage one reaction.

[0019] As a further improvement of the above solution, the amount of cyclohexanone added is 0.3% to 0.7% of the precipitate. In the present invention, the addition of cyclohexanone improves the crystal morphology, enhances the catalytic activity and stability, and overcomes the problem of metal residue.

[0020] As a further improvement of the above scheme, the reaction conditions of the stage one are as follows: temperature 60-70°C, pressure 1-2 MPa, reaction time 2-3 h; the polyether synthesized in the stage one has a molecular weight of 500-1000.

[0021] As a further improvement of the above scheme, the specific operation of the stage one synthesis treatment is as follows: add the main catalyst to the low-carbon alcohol, stir and heat it to 60-70°C, and slowly introduce the epoxide. During the feeding process, control the temperature to 60-70°C and the pressure to 1-2MPa. After the feeding is completed, keep the reaction warm for 2h.

[0022] As a further improvement of the above solution, the low-carbon alcohol is any one of methanol, ethanol, propanol and butanol, and the epoxide is at least one of ethylene oxide and propylene oxide.

[0023] As a further improvement of the above solution, the weight ratio of the epoxide to the low-carbon alcohol is 10 to 30:1.

[0024] As a further improvement of the above scheme, the reaction temperature of the second stage is 70-80°C, and in the second stage, infrared spectroscopy is used to monitor the molecular weight growth. The molecular weight of the polyether synthesized in the second stage is 1000-3000.

[0025] As a further improvement to the above scheme, the ratio of the epoxide introduced in stage 2 to the epoxide introduced in stage 1 is 1.5 to 2.5:1. In the present invention, stage 2 is designed to achieve polyether chain growth, molecular weight control, and molecular structure adjustment. Stage 2 can also adjust the oil solubility of the synthesized polyether. Specifically, the higher the proportion of alkylene oxide in the polyether synthesized in stage 2, the greater the solubility of the polyether.

[0026] As a further improvement of the above scheme, the specific operation of the second stage synthesis treatment is as follows: 1-methylimidazole is dispersed in the graphene oxide solution to obtain an auxiliary catalyst. After the insulation is completed, the auxiliary catalyst is added and the temperature is raised to 70-80°C, and the epoxide is continued to be introduced. During the feeding process, the temperature is controlled at 70-80°C and the pressure is 1-2 MPa. After the feeding is completed, the reaction is kept warm for 4-5 hours.

[0027] As a further improvement to the above solution, the graphene oxide content in the graphene oxide solution is 1% to 2% of the 1-methylimidazole. In the present invention, the graphene oxide improves the dispersibility of the 1-methylimidazole in the solution during the second stage reaction, thereby enhancing the uniformity and stability of the chain growth reaction in the polyether synthesis.

[0028] As a further improvement of the above solution, the weight ratio of the 1-methylimidazole to the DMC catalyst is 1:4 to 6. In the present invention, the 1-methylimidazole plays a role in promoting chain growth.

[0029] As a further improvement of the above solution, the weight ratio of the polyol to the low-carbon alcohol is 1:1, and the added amount of the Lewis acid catalyst accounts for 1% to 2% of the polyol.

[0030] As a further improvement of the above solution, the polyol is any one of glycerol, propylene glycol, sorbitol and trimethylolpropane, and the Lewis acid catalyst is boron trifluoride etherate or zinc dichloride.

[0031] As a further improvement of the above scheme, the reaction conditions of the stage three are as follows: temperature 90-100° C., reaction pressure ≤0.9 MPa, and reaction time 3-5 h.

[0032] As a further improvement to the above scheme, the third stage synthesis process is specifically performed as follows: add a polyol and a Lewis acid catalyst, raise the temperature to 90-100°C with stirring, control the reaction pressure to ≤0.9 MPa, maintain the reaction under these conditions for 5 hours, discharge, filter, and meter to obtain the polyether product. This invention is designed to introduce polyol monomers in the third stage and modify the polyether chain ends with hydroxyl groups, thereby optimizing the terminal structure of the polyether polymer chain and improving the thermal stability and weather resistance of the polyether product.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention adopts a method of adjusting the proportion of alkylene oxide in the polyether molecule during synthesis to obtain polyethers with different solubilities to meet different application requirements.

[0035] The synthesis process of the present invention establishes a three-stage modular reaction system. The first stage is used to synthesize low-molecular-weight polyether for chain growth in the second stage. The second stage is used to increase the proportion of alkylene oxide in the polyether molecular structure to adjust the oil solubility of the synthesized polyether. Finally, the third stage is used to modify the hydroxyl groups at the ends of the polyether chain to improve the thermal stability and weather resistance of the polyether product.

[0036] The present invention utilizes a DMC catalyst to perform a primary catalytic role and 1-methylimidazole to perform a secondary catalytic role, achieving a primary and secondary synergistic catalysis that improves synthesis efficiency while also promoting the selectivity of different reactions. Furthermore, the large specific surface area and rich functional group structure of graphene oxide are utilized to improve the dispersibility of the DMC catalyst in the solution during the first stage reaction, thereby enhancing the uniformity and stability of the initiation reaction of polyether synthesis. Furthermore, during the second stage reaction, the dispersibility of 1-methylimidazole in the solution is enhanced, thereby enhancing the uniformity and stability of the chain growth reaction of polyether synthesis. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the embodiments. Additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through practice of the present invention. It should be understood that the following description is only intended to explain the present invention and is not intended to limit the present invention.

[0038] As used herein, the terms "comprises," "includes," "contains," or any other variations thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0039] When amount, concentration or other value or parameter is expressed as range, preferred range, or a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when disclosing a range of "1 to 5", the described range should be interpreted as including ranges of "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5" etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0040] The specific embodiments of the present invention are described in detail below.

[0041] Example 1

[0042] This embodiment provides a modular synthesis process for oil-soluble polyethers based on collaborative catalysis, which comprises the following steps:

[0043] S1: DMC catalyst is dispersed in graphene oxide solution to obtain a main catalyst.

[0044] The DMC catalyst is cobalt zinc cyanide crystals with a crystal size of 20 to 50 nm. The chemical formula of cobalt zinc cyanide crystals is Zn3[Co(CN)6]2·xH2O, where x represents the hydrate content. In the graphene oxide solution, the graphene oxide content accounts for 1% of the DMC catalyst. Leveraging its large specific surface area and rich functional group structure, in this embodiment, the graphene oxide improves the dispersibility of the DMC catalyst in the solution during the first stage reaction, thereby enhancing the uniformity and stability of the initiation reaction for polyether synthesis.

[0045] The method for preparing cobalt zinc cyanide crystals specifically comprises the following steps: dissolving a cobalt salt and a zinc salt in a ratio of 1:2 in water to obtain a salt solution; dripping triethanolamine into the salt solution; subjecting the mixture to hydrothermal treatment to form a precursor; filtering and washing the mixture; retaining the precipitate; adding cyclohexanone to the precipitate for reaction; and finally separating and drying the mixture to obtain cobalt zinc cyanide crystals.

[0046] The amount of triethanolamine added accounts for 2% of the total amount of cobalt and zinc salts. In this embodiment, triethanolamine is added for surface modification, improving the compatibility of the catalyst with methanol and ethylene oxide, thereby enhancing the initiation ability of the stage 1 reaction. The amount of cyclohexanone added accounts for 0.3% of the precipitate. In this embodiment, the addition of cyclohexanone improves the crystal morphology, enhances catalytic activity and stability, and overcomes the problem of metal residue.

[0047] S2 methanol and ethylene oxide are subjected to a stage one synthesis treatment of polyether under the action of a main catalyst. The polyether obtained by the stage one synthesis has a molecular weight of 500 to 1000.

[0048] The methanol is any one of methanol, ethanol, propanol and butanol; the ethylene oxide is at least one of ethylene oxide and propylene oxide.

[0049] The specific operation of the first stage synthesis process is as follows: methanol is placed in a dry, clean reactor, the primary catalyst is added, and after stirring and heating to 60°C, ethylene oxide is slowly introduced. The temperature and pressure are controlled at 60°C and 1 MPa during the process. After the addition is completed, the reaction is kept warm for 2 hours. The weight ratio of ethylene oxide to methanol is 10:1. In this example, the first stage is designed to synthesize low-molecular-weight polyethers for chain extension in the second stage.

[0050] S3 continues to add 1-methylimidazole, graphene oxide solution and ethylene oxide to carry out the second stage synthesis treatment of polyether. In the second stage, infrared spectroscopy is used to monitor the molecular weight growth. The molecular weight of the polyether obtained by the second stage synthesis is 1000-3000.

[0051] The ratio of ethylene oxide introduced in stage 2 to the ethylene oxide introduced in stage 1 is 1.5:1. In this embodiment, stage 2 is designed to achieve polyether chain growth, molecular weight control, and molecular structure adjustment. Stage 2 can also adjust the oil solubility of the synthesized polyether. Specifically, the higher the proportion of alkylene oxide in the polyether molecules synthesized in stage 2, the greater the solubility of the polyether.

[0052] The specific operation of the second stage synthesis treatment is as follows: 1-methylimidazole is dispersed in the graphene oxide solution to obtain an auxiliary catalyst. After the insulation is completed, the auxiliary catalyst is added and the temperature is raised to 70°C. Ethylene oxide is continued to be introduced. The temperature is controlled at 70°C and the pressure is 1MPa during the feeding process. After the feeding is completed, the reaction is kept warm for 4 hours.

[0053] The graphene oxide solution contains 1% of the 1-methylimidazole. Leveraging its large surface area and rich functional group structure, the graphene oxide improves the dispersibility of the 1-methylimidazole in the solution during the second stage reaction, thereby enhancing the uniformity and stability of the chain growth reaction in the polyether synthesis.

[0054] The weight ratio of the 1-methylimidazole to the DMC catalyst is 1:4. In this embodiment, the 1-methylimidazole plays a role in promoting chain growth, the DMC catalyst plays a primary catalytic role, and the 1-methylimidazole plays a secondary catalytic role. The primary and secondary catalytic synergistic catalysis improves the synthesis efficiency while promoting the selectivity of different reactions.

[0055] S4 continues to add glycerol, and performs the three-stage synthesis treatment of polyether under the action of boron trifluoride ether to obtain a polyether product. The weight ratio of glycerol and methanol is 1:1, and the amount of boron trifluoride ether added accounts for 1% of glycerol.

[0056] The specific operation of the third stage synthesis process is as follows: glycerol and boron trifluoride etherate are added, the temperature is raised to 90°C with stirring, the reaction pressure is controlled at ≤0.9 MPa, the reaction is maintained under these conditions for 5 hours, and the product is discharged, filtered, and measured to obtain the polyether product. In this embodiment, the third stage is designed to introduce glycerol monomer and modify the polyether chain ends with hydroxyl groups, thereby optimizing the terminal structure of the polyether polymer chain and improving the thermal stability and weather resistance of the polyether product.

[0057] Example 2

[0058] This embodiment provides a modular synthesis process for oil-soluble polyethers based on collaborative catalysis, which comprises the following steps:

[0059] S1: DMC catalyst is dispersed in graphene oxide solution to obtain a main catalyst.

[0060] The DMC catalyst is cobalt zinc cyanide crystals with a crystal size of 20 to 50 nm. The chemical formula of cobalt zinc cyanide crystals is Zn3[Co(CN)6]2·xH2O, where x represents the hydrate content. In the graphene oxide solution, the graphene oxide content accounts for 1.3% of the DMC catalyst. Leveraging its large specific surface area and rich functional group structure, in this embodiment, the graphene oxide improves the dispersibility of the DMC catalyst in the solution during the first stage reaction, thereby enhancing the uniformity and stability of the initiation reaction for polyether synthesis.

[0061] The method for preparing cobalt zinc cyanide crystals comprises the following steps: dissolving a cobalt salt and a zinc salt in a ratio of 1:2.4 in water to obtain a salt solution; dripping triethanolamine into the salt solution; performing hydrothermal treatment to form a precursor; filtering and washing the precursor; retaining the precipitate; adding cyclohexanone to the precipitate for reaction; and separating and drying the precipitate to obtain cobalt zinc cyanide crystals.

[0062] The amount of triethanolamine added accounts for 2.5% of the total amount of cobalt salt and zinc salt. In this embodiment, triethanolamine is added for surface modification to improve the compatibility of the catalyst with ethanol and propylene oxide, thereby achieving the effect of improving the initiation ability of the stage 1 reaction. The amount of cyclohexanone added accounts for 0.5% of the precipitate. In this embodiment, the addition of cyclohexanone improves the crystal morphology, enhances catalytic activity and stability, and overcomes the problem of metal residue.

[0063] S2 ethanol and propylene oxide are subjected to a stage one synthesis treatment of polyether under the action of a main catalyst. The polyether obtained by the stage one synthesis has a molecular weight of 500 to 1000.

[0064] The specific operation of the first stage synthesis process is as follows: ethanol is added to a dry, clean reactor, the primary catalyst is continuously added, and the temperature is raised to 65°C with stirring. Then, propylene oxide is slowly introduced. The temperature and pressure are controlled at 65°C and 1.5 MPa during the process. After the addition is completed, the reaction is incubated for 2 hours. The weight ratio of propylene oxide to ethanol is 15:1. In this example, the first stage is designed to synthesize low-molecular-weight polyethers for chain extension in the second stage.

[0065] S3 continues to add 1-methylimidazole, graphene oxide solution and propylene oxide to carry out the second stage synthesis treatment of polyether. In the second stage, infrared spectroscopy is used to monitor the molecular weight growth. The molecular weight of the polyether obtained by the second stage synthesis is 1000-3000.

[0066] The ratio of propylene oxide introduced in stage 2 to the propylene oxide introduced in stage 1 is 2:1. In this embodiment, stage 2 is designed to achieve polyether chain growth, molecular weight control, and molecular structure adjustment. Stage 2 can also adjust the oil solubility of the synthesized polyether. Specifically, the higher the proportion of alkylene oxide in the polyether molecules synthesized in stage 2, the greater the solubility of the polyether.

[0067] The specific operation of the second stage synthesis treatment is as follows: 1-methylimidazole is dispersed in the graphene oxide solution to obtain an auxiliary catalyst. After the insulation is completed, the auxiliary catalyst is added and the temperature is raised to 75°C. Propylene oxide is continued to be introduced. The temperature is controlled at 75°C and the pressure is 1.5MPa during the feeding process. After the feeding is completed, the reaction is kept warm for 4.5 hours.

[0068] The graphene oxide solution contained 1.5% of the 1-methylimidazole. Leveraging its large surface area and rich functional group structure, the graphene oxide in this embodiment improves the dispersibility of the 1-methylimidazole in the solution during the second stage reaction, thereby enhancing the uniformity and stability of the chain growth reaction in the polyether synthesis.

[0069] The weight ratio of the 1-methylimidazole to the DMC catalyst is 1:5. In this embodiment, the 1-methylimidazole plays a role in promoting chain growth, the DMC catalyst plays a primary catalytic role, and the 1-methylimidazole plays a secondary catalytic role. The primary and secondary catalytic synergistic catalysis improves the synthesis efficiency while promoting the selectivity of different reactions.

[0070] In step S4, allyl alcohol is continuously added, and the three-stage synthesis treatment of polyether is carried out under the action of zinc dichloride to obtain a polyether product. The weight ratio of allyl alcohol to ethanol is 1:1, and the amount of zinc dichloride added accounts for 1.3% of allyl alcohol.

[0071] The specific steps of the third stage synthesis process are as follows: add allyl alcohol and zinc dichloride, raise the temperature to 95°C with stirring, control the reaction pressure to ≤0.9 MPa, maintain the reaction under these conditions for 5 hours, and then discharge, filter, and meter the product to obtain the polyether product. In this example, the third stage is designed to introduce allyl alcohol monomer and modify the polyether chain ends with hydroxyl groups, thereby optimizing the terminal structure of the polyether polymer chain and improving the thermal stability and weather resistance of the polyether product.

[0072] Example 3

[0073] This embodiment provides a modular synthesis process for oil-soluble polyethers based on collaborative catalysis, which comprises the following steps:

[0074] S1: DMC catalyst is dispersed in graphene oxide solution to obtain a main catalyst.

[0075] The DMC catalyst is cobalt zinc cyanide crystals with a crystal size of 20 to 50 nm. The chemical formula of cobalt zinc cyanide crystals is Zn3[Co(CN)6]2·xH2O, where x represents the hydrate content. In the graphene oxide solution, the graphene oxide content accounts for 2% of the DMC catalyst. Leveraging its large specific surface area and rich functional group structure, in this embodiment, the graphene oxide improves the dispersibility of the DMC catalyst in the solution during the first stage reaction, thereby enhancing the uniformity and stability of the initiation reaction for polyether synthesis.

[0076] The method for preparing cobalt zinc cyanide crystals comprises the following steps: dissolving a cobalt salt and a zinc salt in a ratio of 1:3 in water to obtain a salt solution; dripping triethanolamine into the salt solution; performing hydrothermal treatment to form a precursor; filtering and washing the precipitate; adding cyclohexanone to the precipitate for reaction; and separating and drying the precipitate to obtain cobalt zinc cyanide crystals.

[0077] The amount of triethanolamine added accounts for 4% of the total amount of the cobalt salt and zinc salt. In this embodiment, the addition of triethanolamine for surface modification improves the compatibility of the catalyst with propanol and propylene oxide, thereby achieving the effect of improving the initiation ability of the stage 1 reaction. The amount of cyclohexanone added accounts for 0.7% of the precipitate. In this embodiment, the addition of cyclohexanone improves the crystal morphology, enhances the catalytic activity and stability, and overcomes the problem of metal residue.

[0078] S2 propanol and propylene oxide are subjected to a stage one synthesis treatment of polyether under the action of a main catalyst. The polyether obtained by the stage one synthesis has a molecular weight of 500 to 1000.

[0079] The specific operation of the first stage synthesis process is as follows: propanol is placed in a dry, clean reactor, the primary catalyst is added, and the temperature is raised to 70°C with stirring. Then, propylene oxide is slowly introduced. The temperature and pressure are controlled at 70°C and 2 MPa during the process. After the addition is completed, the reaction is kept at this temperature for 2 hours. The weight ratio of propylene oxide to propanol is 20:1. In this example, the first stage is designed to synthesize low-molecular-weight polyethers for chain extension in the second stage.

[0080] S3 continues to add 1-methylimidazole, graphene oxide solution and propylene oxide to carry out the second stage synthesis treatment of polyether. In the second stage, infrared spectroscopy is used to monitor the molecular weight growth. The molecular weight of the polyether obtained by the second stage synthesis is 1000-3000.

[0081] The ratio of propylene oxide introduced in stage 2 to the propylene oxide introduced in stage 1 is 2.5:1. In this embodiment, stage 2 is designed to achieve polyether chain growth, molecular weight control, and molecular structure adjustment. Stage 2 can also adjust the oil solubility of the synthesized polyether. Specifically, the higher the proportion of alkylene oxide in the polyether molecules synthesized in stage 2, the greater the solubility of the polyether.

[0082] The specific operation of the second stage synthesis treatment is as follows: 1-methylimidazole is dispersed in the graphene oxide solution to obtain an auxiliary catalyst. After the insulation is completed, the auxiliary catalyst is added and the temperature is raised to 80°C. Propylene oxide is continued to be introduced. The temperature is controlled at 80°C and the pressure is 2MPa during the feeding process. After the feeding is completed, the reaction is kept warm for 5 hours.

[0083] The graphene oxide solution contains 2% of the 1-methylimidazole. Leveraging its large surface area and rich functional group structure, the graphene oxide improves the dispersibility of the 1-methylimidazole in the solution during the second stage reaction, thereby enhancing the uniformity and stability of the chain growth reaction in the polyether synthesis.

[0084] The weight ratio of the 1-methylimidazole to the DMC catalyst is 1:6. In this embodiment, the 1-methylimidazole plays a role in promoting chain growth, the DMC catalyst plays a primary catalytic role, and the 1-methylimidazole plays a secondary catalytic role. The primary and secondary catalytic synergistic catalysis improves the synthesis efficiency while promoting the selectivity of different reactions.

[0085] S4 continues to add allyl alcohol, and performs the three-stage synthesis treatment of polyether under the action of zinc dichloride to obtain a polyether product. The weight ratio of allyl alcohol to propanol is 1:1, and the amount of zinc dichloride added accounts for 2% of allyl alcohol.

[0086] The specific operations of the stage three synthesis process are as follows: add allyl alcohol and zinc dichloride, stir, heat to 100°C, control the reaction pressure to ≤ 0.9 MPa, maintain the reaction under these conditions for 5 hours, discharge, filter, and meter to obtain the polyether product. In this example, stage three is designed to introduce allyl alcohol monomer and modify the polyether chain ends with hydroxyl groups, thereby optimizing the terminal structure of the polyether polymer chain and improving the thermal stability and weather resistance of the polyether product.

[0087] The above embodiments are merely preferred implementations of the present invention. Any simple modifications, amendments, and substitutions made to the above embodiments based on the technical essence of the present invention fall within the scope of the technical solution of the present invention.

Claims

1. A modular synthesis process for oil-soluble polyethers based on synergistic catalysis, characterized in that: The following steps are involved: S1: DMC catalyst is dispersed in graphene oxide solution to obtain the main catalyst; S2 low carbon alcohol and epoxide, under the action of main catalyst, carry out the first stage synthesis treatment of polyether; S3 continues to add 1-methylimidazole, graphene oxide solution and epoxide to carry out the second stage synthesis of polyether; In S4, polyol is continuously added to carry out the three-stage synthesis of polyether under the action of Lewis acid catalyst to obtain a polyether product.

2. The modular synthesis process of oil-soluble polyether based on synergistic catalysis according to claim 1, characterized in that: The DMC catalyst is a cobalt zinc cyanide crystal with a crystal size of 20 to 50 nm; In the graphene oxide solution, the content of graphene oxide accounts for 1% to 2% of the DMC catalyst.

3. The modular synthesis process of oil-soluble polyether based on synergistic catalysis according to claim 2, characterized in that: The preparation method of the cobalt zinc cyanide crystal is specifically performed as follows: S11: dissolving a cobalt salt and a zinc salt in water in a ratio of 1:2 to 3 to obtain a salt solution; S12 continues to dropwise add triethanolamine to the salt solution to form a precursor through hydrothermal treatment; After S13 filtering and washing, the precipitate is retained and cyclohexanone is added to react, and then separated and dried to obtain cobalt zinc cyanide crystals.

4. The modular synthesis process of oil-soluble polyether based on synergistic catalysis according to claim 3, characterized in that: The amount of triethanolamine added is 2% to 4% of the total amount of cobalt salt and zinc salt; The added amount of the cyclohexanone accounts for 0.3% to 0.7% of the precipitate.

5. The modular synthesis process of oil-soluble polyether based on synergistic catalysis according to claim 1, characterized in that: The reaction conditions of the first stage are as follows: temperature 60-70°C, pressure 1-2 MPa, reaction time 2-3 hours; the polyether synthesized in the first stage has a molecular weight of 500-1000; The first stage of the synthesis process is specifically performed as follows: a main catalyst is added to the low-carbon alcohol, the temperature is stirred and heated to 60-70° C., and the epoxide is slowly introduced. During the introduction process, the temperature is controlled at 60-70° C. and the pressure is controlled at 1-2 MPa. After the introduction is completed, the reaction is kept warm for 2 hours.

6. The modular synthesis process of oil-soluble polyether based on synergistic catalysis according to claim 5, characterized in that: The low-carbon alcohol is any one of methanol, ethanol, propanol and butanol; the epoxide is at least one of ethylene oxide and propylene oxide; The weight ratio of the epoxide to the low-carbon alcohol is 10 to 30:

1.

7. The modular synthesis process of oil-soluble polyether based on synergistic catalysis according to claim 1, characterized in that: The reaction temperature of the second stage is 70-80°C, and in the second stage, infrared spectroscopy is used to monitor the molecular weight growth. The molecular weight of the polyether synthesized in the second stage is 1000-3000. The ratio of the epoxide introduced in the second stage to the epoxide introduced in the first stage is 1.5 to 2.5:

1.

8. The modular synthesis process of oil-soluble polyether based on synergistic catalysis according to claim 7, characterized in that: The second stage of the synthesis process is specifically performed as follows: 1-methylimidazole is dispersed in a graphene oxide solution to obtain an auxiliary catalyst. After the insulation is completed, the auxiliary catalyst is added and the temperature is raised to 70-80°C. The epoxide is continuously introduced. The temperature is controlled at 70-80°C and the pressure is 1-2 MPa during the feeding process. After the feeding is completed, the reaction is kept warm for 4-5 hours. In the graphene oxide solution, the content of graphene oxide accounts for 1% to 2% of 1-methylimidazole; the weight ratio of the 1-methylimidazole to the DMC catalyst is 1:4 to 6.

9. The modular synthesis process of oil-soluble polyether based on synergistic catalysis according to claim 1, characterized in that: The weight ratio of the polyol and the low-carbon alcohol is 1:1, and the amount of the Lewis acid catalyst added accounts for 1% to 2% of the polyol; The polyol is any one of glycerol, propylene glycol, sorbitol and trimethylolpropane; the Lewis acid catalyst is boron trifluoride etherate or zinc dichloride; The reaction conditions of the third stage are as follows: temperature 90-100° C., reaction pressure ≤ 0.9 MPa, and reaction time 3-5 h.

10. The modular synthesis process of oil-soluble polyether based on synergistic catalysis according to claim 9, characterized in that: The specific operation of the stage three synthesis treatment is as follows: adding polyol and Lewis acid catalyst, stirring and heating to 90-100° C., controlling the reaction pressure ≤ 0.9 MPa, keeping the reaction under this reaction condition for 5 hours, discharging, filtering, and measuring to obtain the polyether product.