Preparation method of perfluoro-n-propyl vinyl ether
By using a combination of fluoride catalysts and phase transfer catalysts and optimizing reaction conditions, the problems of low purity and yield of PPVE in the prior art were solved, and high-purity and high-yield PPVE preparation was achieved, simplifying the post-processing.
Patent Information
- Application Number
- CN202511267117.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-05
- Publication Date
- 2026-01-09
AI Technical Summary
Existing methods for preparing perfluoropropyl vinyl ether (PPVE) suffer from problems such as harsh reaction conditions, unsatisfactory product purity and yield, numerous byproducts, and complex post-processing.
Using hexafluoropropylene oxide as raw material, and fluorides such as potassium fluoride or cesium fluoride as rearrangement catalysts, the reaction is carried out in a polar aprotic solvent. By combining phase transfer catalysts and distillation technology, the reaction temperature and pressure are controlled to produce high-purity PPVE.
It improves the purity of PPVE to over 99.5%, reduces the content of metal and metal ion impurities to less than 1 ppm, increases the yield by 10-20%, simplifies post-processing, reduces production costs and environmental pollution, and lowers equipment requirements.
Smart Images
Figure BDA0005583598590000021
Abstract
Description
Technical Field
[0001] This invention relates to the field of organic synthesis technology, and in particular to a method for preparing perfluoropropyl vinyl ether. Background Technology
[0002] Perfluoropropyl vinyl ether (PPVE) is an extremely important fluorinated monomer, holding an irreplaceable position in the synthesis of fluoropolymers. In the synthesis of fluoropolymers, when PPVE is copolymerized with tetrafluoroethylene (TFE) to prepare soluble polytetrafluoroethylene (PFA), it effectively improves the flexibility of the PFA polymer chain, reduces crystallinity, and imparts good thermoplasticity to PFA. This allows PFA to retain the excellent chemical stability, physical and mechanical properties, and electrical insulation of PFA while significantly improving its high-temperature mechanical properties, thus solving the problem of PFA's difficult processing. In the synthesis of fluororubber, the introduction of PPVE can improve the rubber's low-temperature resistance, toughness, and tear resistance. The resulting perfluoroether rubber is widely used in high-end industries such as semiconductors. Furthermore, PPVE is also used to introduce fluorine functional groups into organic molecules, playing a role in the agricultural and pharmaceutical industries.
[0003] Currently, there are various methods for preparing PPVE, but all have some problems. Traditional methods often use hexafluoropropylene oxide as a raw material, preparing perfluoro-2-propoxypropionyl fluoride in a polar solvent using a metal halide as a catalyst, followed by thermal cracking to produce PPVE, and finally purification by distillation. However, ordinary distillation is difficult to effectively remove unreacted perfluoro-2-propoxypropionyl fluoride reacting with water to form 2-propoxypropionic acid, as well as acids produced during the decomposition process. These acidic substances will acidify the PPVE product, severely affecting subsequent polymerization reactions. Simultaneously, this process easily generates byproducts such as hydrogen ethers (CF2-O-CFH-CF3). PPVE obtained using conventional distillation and other separation methods generally has a purity of over 99.0%, and the product usually contains approximately 1 ppm to approximately 100 ppm of metal or metal ion impurities, such as iron (Fe), zinc (Zn), sodium (Na), calcium (Ca), and manganese (Mn). These impurities will adversely affect the polymerization reaction involving PPVE, reducing the polymer's performance. There is also a method to prepare PPVE by thermal decomposition of perfluoroisopropyl vinyl ether (iso-PPVE), which requires heating the mixture of isomers to a high temperature of 250℃-350℃. This method is not only energy-intensive and has demanding equipment requirements, but also involves a complex process of separating the pyrolysis products of perfluoroisopropyl vinyl ether (iso-PPVE) from perfluoron-propyl vinyl ether (PPVE), making it difficult to obtain high-purity PPVE.
[0004] Therefore, developing a method for preparing PPVE with mild reaction conditions, few side reactions, high product purity, and high yield has significant practical importance and industrial application value.
[0005] In view of this, the present invention is proposed. Summary of the Invention
[0006] The purpose of this invention is to provide a method for preparing perfluoropropyl vinyl ether, so as to solve the problems of harsh reaction conditions, unsatisfactory product purity and yield, many by-products and complicated post-processing in existing preparation methods.
[0007] In a first aspect, the present invention provides a method for preparing perfluoropropyl vinyl ether, comprising the following steps: using hexafluoropropylene oxide (HFPO) as a raw material, sequentially adding a rearrangement catalyst and tetrafluoroethylene (TFE) to react and obtain perfluoropropyl vinyl ether (PPVE).
[0008] Preferably, the rearrangement catalyst is a fluoride; the fluoride includes any one or more of potassium fluoride and cesium fluoride.
[0009] Preferably, the rearrangement catalyst is dispersed in a polar aprotic solvent; the polar aprotic solvent includes any one or more of diethylene glycol dimethyl ether, N,N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO).
[0010] The specific reaction formula is as follows:
[0011]
[0012] Using potassium fluoride as a rearrangement catalyst and ethylene glycol dimethyl ether as a polar aprotic solvent, the specific reaction process is as follows: hexafluoropropylene oxide rearranges in potassium fluoride in ethylene glycol dimethyl ether to obtain perfluoropropionyl fluoride, which then generates potassium perfluoropropoxide. The reaction between perfluoropropionyl fluoride and potassium perfluoropropoxide is reversible and occurs in an equilibrium state. After adding tetrafluoroethylene, the reaction yields perfluoropropyl vinyl ether.
[0013] Preferably, the steps include:
[0014] S1. Add the rearrangement catalyst and polar aprotic solvent to the reaction vessel, start stirring and heat to 50-70℃ to fully disperse the rearrangement catalyst in the polar aprotic solvent;
[0015] S2. Add hexafluoropropylene oxide to the reaction vessel. Under the action of the rearrangement catalyst, hexafluoropropylene oxide undergoes a rearrangement reaction.
[0016] S3. Transfer the rearrangement reaction product to a high-pressure reactor and add a phase transfer catalyst;
[0017] S4. After purging nitrogen into the high-pressure reactor to replace the air, heat the reactor to 80-100℃, then introduce tetrafluoroethylene to react fully and generate perfluoropropyl vinyl ether.
[0018] Preferably, the following steps are included between steps S2 and S3:
[0019] S23. Remove some of the polar aprotic solvent by vacuum distillation to obtain the concentrated rearrangement reaction product.
[0020] Preferably, after step S4, the following steps are also included:
[0021] S5. Unreacted tetrafluoroethylene and other impurities are separated by distillation, and the fraction with a boiling point of 35-35.5℃ is collected to obtain high-purity perfluoropropyl vinyl ether.
[0022] Preferably, in step S2, hexafluoropropylene oxide is introduced slowly over a period of 1-3 hours, the reaction temperature is kept stable during the introduction process, and the reaction continues for 3-5 hours after the introduction is completed.
[0023] Preferably, in step S3, the phase transfer catalyst includes any one or more of tetrabutylammonium bromide and benzyltriethylammonium chloride.
[0024] Preferably, in step S4, the reaction pressure is controlled at 1.0-1.5 MPa and the reaction time is 4-6 hours.
[0025] In a second aspect, the present invention provides a perfluoropropyl vinyl ether prepared by the method described above.
[0026] A third aspect of the present invention provides the application of the aforementioned perfluoropropyl vinyl ether in the fields of medical devices, chemical production, semiconductor manufacturing, agriculture, pharmaceuticals, new energy, and electronics.
[0027] Compared with the prior art, the present invention has at least the following beneficial effects:
[0028] (1) High product quality: By optimizing the reaction raw materials and conditions, the generation of by-products was effectively reduced, and the selectivity and purity of the target product were improved. The purity of the prepared PPVE can reach more than 99.5%, and the content of metal and metal ion impurities is less than 1 ppm, which can meet the strict requirements of high-end fields for PPVE quality and provide high-quality monomer raw materials for subsequent synthesis of high-performance fluoropolymers.
[0029] (2) High yield: In each step of the reaction, by precisely controlling the reaction raw materials and conditions, the conversion rate of hexafluoropropylene oxide and the yield of PPVE have been significantly improved. The overall yield is 10-20% higher than that of the traditional method, which is conducive to large-scale industrial production, reducing production costs and improving the economic benefits of enterprises.
[0030] (3) Simple post-processing: The types of by-products generated during the reaction are few and easy to separate. The post-processing after the reaction is simple and does not require complicated distillation and purification steps, which reduces production steps and time, and also reduces product loss and environmental pollution caused by the post-processing.
[0031] (4) Mild reaction conditions: The reaction temperature and pressure of the entire preparation process are within a relatively low and easily controllable range. Extreme conditions such as high temperature and high pressure are not required, which reduces the requirements for reaction equipment, reduces equipment investment and operating costs, and also improves the safety and stability of the production process. Detailed Implementation
[0032] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.
[0033] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form includes the plural form unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0034] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0035] Example 1
[0036] This embodiment provides a method for preparing perfluoropropyl vinyl ether, comprising the following steps:
[0037] In a dry four-necked flask equipped with a stirrer, thermometer, and reflux condenser, add 38g of anhydrous potassium fluoride and 400mL of N,N-dimethylformamide, turn on the stirrer and heat to 60°C to fully disperse the anhydrous potassium fluoride in the solvent.
[0038] Slowly introduce 100g of hexafluoropropylene oxide over 1.5 hours; after the introduction is complete, continue to react fully for 4 hours.
[0039] After the reaction was completed, some of the solvent was removed by vacuum distillation to obtain a concentrated solution.
[0040] Transfer the concentrate to a high-pressure reactor equipped with a gas inlet pipe and a stirring device, and add 12g of tetrabutylammonium bromide;
[0041] The high-pressure reactor was sealed, and nitrogen was introduced to replace the air three times. The temperature was raised to 90°C, and tetrafluoroethylene was slowly introduced. The reaction pressure was controlled at 1.2 MPa, and the reaction was allowed to proceed for 5 hours to generate PPVE.
[0042] After the reaction was completed, unreacted tetrafluoroethylene and other impurities were separated by distillation. The fraction with a boiling point of 35-35.5℃ was collected to obtain 133g of high-purity PPVE. Analysis showed that the PPVE purity was 99.6%, the yield was 83%, and the metal ion content was 0.10ppm.
[0043] The fluorine spectrum of the perfluoropropyl vinyl ether prepared in this embodiment is as follows: C3F7OCF=CF219F NMR (neat): -81.32(t, 4J(OCF2CF2-CF3,OCF2CF2CF3) 7Hz, 3F,OCF2CF2CF3), -85.59(ddq, 5J(OCF2CF2CF3,F1) 5Hz; 4J(OCF2CF2CF3,F2) 5Hz; 2F,OCF2CF2CF3), -114.85(dd, 2J(FU,F1) 87Hz; 37(FJ*,F2) 67Hz, 1F,F1*[F1* denotes the fluorine atom at C1 intransposition to the C3F7O group]),-122.27(ddt,3J(F1,F2)113Hz,1F,F1),-129.19(m,2F,OCF2CF2CF3),-135.60(ddt,1F,F2)[lit.19F NMR: -83.4(t,4J(OCF2CF2CF3,OCF2CF2CF3)7.5Hz,3F,OCF2CF2CF3),-87.6(ddtq,5J(OCF2CF2CF3,F1)6Hz; 4J(OCF2CF2CF3,F2)6Hz; 3J(OCF2CF2CF3,OCF2CF2CF3)2Hz,2 F,OCF2CF2CF3),-117.0(dd,2J(F1*,F1)86Hz; 3J(F1*,F2)66Hz,1F,F1*),-124.4(dd t,3J(F1,F2)112Hz,1F,F1),-131.2(m,2F,OCF2CF2CF3),-137.7(ddt,1F,F2)
[31] ).
[0044] Example 2
[0045] This embodiment provides a method for preparing perfluoropropyl vinyl ether, comprising the following steps:
[0046] In a dry four-necked flask equipped with a stirrer, thermometer, and reflux condenser, add 40g of anhydrous potassium fluoride and 450mL of dimethyl sulfoxide, turn on the stirrer and heat to 65°C to fully disperse the anhydrous potassium fluoride in the solvent.
[0047] Slowly introduce 110g of hexafluoropropylene oxide over 2 hours; after the introduction is complete, continue the reaction for 5 hours.
[0048] After the reaction was completed, some of the solvent was removed by vacuum distillation to obtain a concentrated solution.
[0049] Transfer the concentrate to a high-pressure reactor equipped with a gas inlet pipe and a stirring device, and add 13g of benzyltriethylammonium chloride;
[0050] The high-pressure reactor was sealed, and nitrogen was introduced to replace the air three times. The temperature was raised to 95°C, and tetrafluoroethylene was slowly introduced while controlling the pressure at 1.3 MPa. The reaction was allowed to proceed for 4.5 hours to generate PPVE.
[0051] After the reaction was completed, unreacted tetrafluoroethylene and other impurities were separated by distillation. The fraction with a boiling point of 35-35.5℃ was collected to obtain 148g of high-purity PPVE. Analysis showed that the PPVE purity was 99.7%, the yield was 84%, and the metal ion content was 0.13ppm.
[0052] Example 3
[0053] This embodiment provides a method for preparing perfluoropropyl vinyl ether, comprising the following steps:
[0054] In a dry four-necked flask equipped with a stirrer, thermometer, and reflux condenser, add 100g of anhydrous cesium fluoride and 750mL of diethylene glycol dimethyl ether, turn on the stirrer and heat to 62°C to fully disperse the anhydrous cesium fluoride in the solvent.
[0055] Slowly introduce 100g of hexafluoropropylene oxide over 3 hours; after the introduction is complete, continue the reaction for 4 hours.
[0056] After the reaction was completed, some of the solvent was removed by vacuum distillation to obtain a concentrated solution.
[0057] Transfer the concentrate to a high-pressure reactor equipped with a gas inlet pipe and a stirring device, and add 15g of benzyltriethylammonium chloride;
[0058] The high-pressure reactor was sealed, and nitrogen was introduced to replace the air three times. The temperature was raised to 95°C, and tetrafluoroethylene was slowly introduced while controlling the pressure at 1.3 MPa. The reaction was allowed to proceed for 4.5 hours to generate PPVE.
[0059] After the reaction was completed, unreacted tetrafluoroethylene and other impurities were separated by distillation. The fraction with a boiling point of 35-35.5℃ was collected to obtain 136g of high-purity PPVE. Analysis showed that the PPVE purity was 99.9%, the yield was 85%, and the metal ion content was 0.09ppm.
[0060] Comparative Example 1
[0061] Perfluoro-2-propoxypropionyl fluoride was prepared from hexafluoropropylene oxide in a polar solvent using a metal halide catalyst, followed by thermal cracking to produce PPVE. In the addition reaction step, DMF was used as the solvent and copper chloride as the catalyst, and the reaction was carried out under the same temperature and pressure. The results showed that the conversion rate of hexafluoropropylene oxide was 80%, and the selectivity of perfluoro-2-propoxypropionyl fluoride was 75%. In the decarboxylation reaction step, sodium carbonate was used as the salt-forming agent. The final PPVE had a purity of 98.5%, a yield of 70%, and contained 1.11 ppm of metal ions, indicating a high content of metal ion impurities in the product.
[0062] Comparative Example 2
[0063] PPVE was prepared by thermal decomposition of perfluoroisopropyl vinyl ether (iso-PPVE). A mixture containing iso-PPVE was heated to 300°C for thermal decomposition. After the reaction, PPVE was separated through a complex separation process. The final PPVE obtained had a purity of 98% and a yield of 65%. However, the separation process was complex and energy-intensive.
[0064] The comparison between the examples and the comparative examples clearly shows that the preparation method provided by the present invention has significant advantages in terms of product purity, yield and reaction conditions, and can effectively overcome the shortcomings of the prior art, and has good prospects for industrial application.
[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for preparing a perfluoropropyl vinyl ether, characterized in that, The process includes the following steps: using hexafluoropropylene oxide as a raw material, a rearrangement catalyst and tetrafluoroethylene are added sequentially to react and obtain perfluoropropyl vinyl ether.
2. The method for preparing perfluoropropyl vinyl ether according to claim 1, characterized in that, The rearrangement catalyst is a fluoride; the fluoride includes any one or more of potassium fluoride and cesium fluoride.
3. The method for preparing perfluoropropyl vinyl ether according to claim 1, characterized in that, The rearrangement catalyst is dispersed in a polar aprotic solvent; the polar aprotic solvent includes any one or more of diethylene glycol dimethyl ether, N,N-dimethylformamide, and dimethyl sulfoxide.
4. The method for preparing perfluoropropyl vinyl ether according to claim 1, characterized in that, Includes the following steps: S1. Add the rearrangement catalyst and polar aprotic solvent to the reaction vessel, start stirring and heat to 50-70℃ to fully disperse the rearrangement catalyst in the polar aprotic solvent; S2. Add hexafluoropropylene oxide to the reaction vessel. Under the action of the rearrangement catalyst, hexafluoropropylene oxide undergoes a rearrangement reaction. S3. Transfer the rearrangement reaction product to a high-pressure reactor and add a phase transfer catalyst; S4. After purging nitrogen into the high-pressure reactor to replace the air, heat the reactor to 80-100℃, then introduce tetrafluoroethylene to react fully and generate perfluoropropyl vinyl ether.
5. The method for preparing perfluoropropyl vinyl ether according to claim 4, characterized in that, The steps between S2 and S3 also include the following: S23. Remove some of the polar aprotic solvent by vacuum distillation to obtain the concentrated rearrangement reaction product.
6. The method for preparing perfluoropropyl vinyl ether according to claim 4, characterized in that, Step S4 is followed by the following steps: S5. Unreacted tetrafluoroethylene and other impurities are separated by distillation, and the fraction with a boiling point of 35-35.5℃ is collected to obtain high-purity perfluoropropyl vinyl ether.
7. The method for preparing perfluoropropyl vinyl ether according to claim 4, characterized in that, In step S3, the phase transfer catalyst includes any one or more of tetrabutylammonium bromide and benzyltriethylammonium chloride.
8. The method for preparing perfluoropropyl vinyl ether according to claim 4, characterized in that, In step S4, the reaction pressure is controlled at 1.0-1.5 MPa, and the reaction time is 4-6 hours.
9. Perfluoropropyl vinyl ether prepared by the method of any one of claims 1-8.
10. The application of the perfluoropropyl vinyl ether according to claim 9 in the fields of medical devices, chemical production, semiconductor manufacturing, agriculture, pharmaceuticals, new energy, and electronics.