Method for preparing perfluorinated oxapropionyl fluoride with high selectivity and high purity and application of perfluorinated oxapropionyl fluoride

Abstract

The invention discloses a method for preparing perfluorooxapropionyl fluoride with high selectivity and high purity and application thereof, and belongs to the technical field of fluorine-containing compounds, the method comprises the following steps: adding a mixed solvent of a fluorine-containing benzene solvent and an ether solvent and an alkali metal fluoride catalyst into a reaction kettle, and stirring for 10-30 minutes at-40-0 DEG C for pretreatment activation; then gaseous perfluoroacyl fluoride and gaseous hexafluoropropylene oxide are introduced into a reaction kettle for a ring-opening reaction, a reaction solution is obtained, and the reaction solution contains liquid perfluorooxapropionyl fluoride; and rectifying the reaction liquid to obtain a pure product of the perfluorooxapropionyl fluoride. The method is simple in process and low in equipment requirement, the boiling point difference between the used ether solvent and the fluorine-containing benzene solvent and the polymerization product is large, separation is convenient, the solvent can be reused after purification, the product selectivity of the method is larger than or equal to 92%, the purity of the obtained perfluorinated oxapropionyl fluoride is larger than or equal to 99.4%, and the effect is excellent.

Description

Technical Field

[0001] This invention belongs to the field of fluorine-containing compound technology, specifically relating to a method for preparing perfluorooxopropionyl fluoride with high selectivity and high purity, and its application. Background Technology

[0002] Perfluoropolyethers (PFPEs) are synthetic polymers that are liquid at room temperature and possess excellent thermal stability, chemical inertness, lubrication properties, and insulation properties, making them widely used in surface modification, lubrication, and coating. Low molecular weight perfluorooxypropionyl fluoride, as a key synthetic precursor for PFPEs, can be efficiently synthesized into high-performance PFPE materials through various reaction pathways, including anionic ring-opening polymerization and polycondensation. Given its crucial role in PFPE synthesis, developing efficient and controllable methods for the synthesis of low molecular weight perfluorooxypropionyl fluoride has significant scientific and industrial value.

[0003] In the prior art, researchers have explored and innovated a series of methods for synthesizing low molecular weight perfluorooxopropionyl fluoride. For example, Chinese patent document CN119263977A discloses a method for preparing perfluoro-2-alkoxypropionyl fluoride, which includes the following steps: acyl fluoride and hexafluoropropylene oxide undergo an addition reaction in a polar aprotic solvent in the presence of an organic base catalyst, a phase transfer catalyst, and a phase transfer co-solvent to obtain perfluoro-2-alkoxypropionyl fluoride; the phase transfer co-solvent is selected from hexafluoropropylene dimer, hexafluoropropylene trimer, or 1,3-bis(trifluoromethylbenzene); Chinese patent document CN117945895A discloses a perfluoro-2-alkoxypropionyl fluoride and its preparation method. In the presence of a polar aprotic solvent, a metal fluoride supported on a support agent is used to catalyze the reaction of acyl fluoride and hexafluoropropylene oxide to obtain perfluoro-2-alkoxypropionyl fluoride. The support agent is a metal oxide, carbon, molecular sieve, or organic material support agent, and the metal fluoride is selected from one or more of alkali metal fluorides and alkaline earth metal fluorides. Chinese patent document with publication number CN106146294A discloses a method for producing perfluoro-2-methoxypropionyl fluoride. In this invention, in the presence of a polar aprotic solvent, under the action of an alkali metal fluoride as the main catalyst and a phase transfer catalyst, carbonyl fluoride reacts with hexafluoropropylene oxide to produce perfluoro-2-methoxypropionyl fluoride. The phase transfer catalyst is selected from one, two, or more combinations of three of polyethers, cyclic crown ethers, quaternary ammonium salts, tertiary amines, quaternary ammonium bases, and quaternary phosphine salts. In the above inventions, perfluorooxopropionyl fluoride is prepared by oligomerization of acyl fluoride and hexafluoropropylene oxide under the action of a catalyst. The reaction mechanism is as follows: the active catalytic component in the catalyst attacks the carbonyl group of the acyl fluoride to obtain an anionic intermediate, which attacks the hexafluoropropylene oxide to complete the oligomerization reaction.

[0004] However, the above inventions require the addition of phase transfer catalysts or the modification of catalysts, and have problems such as complex reaction systems and difficulty in obtaining catalysts. Therefore, it is necessary to develop a stable, simple, efficient and highly selective method for synthesizing low molecular weight perfluorooxopropionyl fluoride. Summary of the Invention

[0005] This invention provides a method for preparing perfluorooxopropionyl fluoride with high selectivity and high purity. By combining fluorinated benzene solvents with ether solvents, the compatibility between the product and the solvent is improved. The product selectivity of this method is ≥92%, and the purity of the obtained perfluorooxopropionyl fluoride is ≥99.4%.

[0006] The specific technical solution adopted is as follows: This invention provides a method for preparing perfluorooxopropionyl fluoride with high selectivity and high purity, comprising the following steps: (1) Add a mixture of fluorinated benzene solvent and ether solvent, and alkali metal fluoride catalyst to the reactor, and stir at -40 to 0℃ for 10 to 30 min for pretreatment activation; (2) Gaseous perfluoroacetyl fluoride and gaseous hexafluoropropylene oxide are introduced into a reaction vessel to carry out a ring-opening reaction to obtain a reaction solution containing liquid perfluoroacetyl fluoride. (3) The reaction solution obtained in step (2) is distilled to obtain perfluorooxopropionyl fluoride, the general structural formula of which is XO-CF(CF3)CFO, where X is CF3-, CF3CF2- or CF3CF2CF2-. The fluorinated benzene solvents are m-difluorotoluene and / or trifluorotoluene; the ether solvents include ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether or tetraethylene glycol dimethyl ether, and the molar ratio of the fluorinated benzene solvents to the ether solvents is 0.1 to 3:1.

[0007] This invention utilizes alkali metal fluoride catalysts, ethers, and fluorinated benzene solvents in ring-opening polymerization. Fluorinated benzene solvents are less polar than ether solvents. In polar aprotic solvents (ethers), they combine with alkali metal fluorides and attack hexafluoropropylene oxide to form carbanion active centers. These active centers are relatively weakly polar and easily separate in strongly polar solvents. The use of fluorinated benzene solvents (weakly polar) effectively prevents product separation during the reaction, accelerates product migration in polar solvents, and increases the reaction rate and selectivity of the starting materials. Furthermore, the polymerization of excess acyl fluoride in both ether and fluorinated benzene solvents at low temperatures inhibits the occurrence of hexafluoropropylene oxide polymer side reactions, further improving reaction selectivity.

[0008] Preferably, the fluorinated benzene solvent is m-difluorotoluene or trifluorotoluene, the ether solvent is diethylene glycol dimethyl ether or triethylene glycol dimethyl ether, and the molar ratio of the fluorinated benzene solvent to the ether solvent is 0.8 to 1.5:1.

[0009] Specifically, the alkali metal fluoride is at least one of potassium fluoride, calcium fluoride, cesium fluoride, rubidium fluoride, and silver fluoride, preferably one of potassium fluoride, calcium fluoride, and cesium fluoride.

[0010] Furthermore, the perfluoroacyl fluoride is perfluoroformyl fluoride CF2O, perfluoroacetyl fluoride CF3CFO, or perfluoropropionyl fluoride CF3CF2CFO.

[0011] Preferably, in step (2), the molar ratio of gaseous perfluoroacyl fluoride to gaseous hexafluoropropylene oxide is 1 to 2:1.

[0012] More preferably, the molar ratio of gaseous perfluoroacyl fluoride to gaseous hexafluoropropylene oxide is 1 to 1.4:1.

[0013] Preferably, gaseous perfluoroacyl fluoride is first introduced into the reactor, followed by gaseous hexafluoropropylene oxide; the ring-opening reaction is assisted by stirring, the ring-opening reaction temperature is -40 to 0℃, the stirring speed is 200 to 2000 rpm, the reaction time is 180 to 360 min, and no pressure needs to be maintained during the reaction, the pressure is continuously reduced.

[0014] Further preferably, the ring-opening reaction temperature is -25 to -10°C, the stirring speed is 400 to 1200 rpm, and the reaction time is 200 to 300 min.

[0015] Preferably, the mass ratio of alkali metal fluoride catalyst to perfluoroacyl fluoride is (0.01-1):1, and more preferably (0.05-0.5):1.

[0016] Preferably, the distillation conditions are: distillation pressure is atmospheric pressure (0.09-0.11 MPa), and distillation temperature is 0-70℃.

[0017] Specifically, perfluorooxopropionyl fluoride exhibits a selectivity of ≥92% during the ring-opening polymerization stage, with few byproducts, and the perfluorooxopropionyl fluoride obtained after distillation has a purity of ≥99.4%, indicating high purity.

[0018] The present invention also provides the application of the method for preparing perfluorooxopropionyl fluoride with high selectivity and high purity in the synthesis of perfluoroalkyl vinyl ethers or perfluoropolyethers.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The method for preparing perfluorooxopropionyl fluoride provided by the present invention has high reaction efficiency and high selectivity. By combining fluorinated benzene solvents with ether solvents, the compatibility between the product and the solvent is improved. Except for the catalyst, the liquid phase is kept homogeneous to improve the reaction efficiency and selectivity. The selectivity of the target product perfluorooxopropionyl fluoride is above 92%, and the purity after distillation is above 99.4%. (2) The reaction process of the method of the present invention is stable and controllable. During the ring-opening reaction, the material ratio is stable and can effectively contact the product, so as to achieve uniform temperature distribution, stability and controllability during the reaction process, and improve the safety of the reaction. (3) The method of the present invention is economical and environmentally friendly. The mixed solvent used can be recycled. The boiling points of fluorinated benzene solvent and ether solvent are quite different, making them easy to separate. The process is simple, saves costs, and reduces the generation of waste. Attached Figure Description

[0020] Figure 1 The NMR spectrum of perfluoroethoxypropionyl fluoride prepared in Example 1 is shown. Detailed Implementation

[0021] To make the objectives, features, and advantages of this invention more apparent and understandable, a detailed description is provided below through specific embodiments. Many specific details are set forth in the following description to provide a thorough understanding of the invention. However, the invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below. Technical features in various embodiments of the invention can be combined appropriately without mutual conflict.

[0022] Unless otherwise specified, the operating methods in the following examples are generally performed under conventional conditions or as recommended by the manufacturer. Contents not described in detail in this specification are prior art known to those skilled in the art. Unless otherwise specified, the experimental materials used in the examples below can be purchased from conventional biochemical reagent companies.

[0023] Example 1 (1) In a 5L pressure vessel, add 86 g KF, 850 g diethylene glycol dimethyl ether and 850 g m-difluorotoluene (moisture content ≤100 ppm), cool to -30℃, start stirring, and stir at 600 rpm for 10 min for pretreatment activation; (2) Subsequently, 800 g of gaseous perfluoroacetyl fluoride was added to the reactor at one time, and then 100 g of gaseous hexafluoropropylene oxide HFPO1 (C3F6O) was introduced. The reaction was carried out at -30℃ for 300 min. The stirring speed was kept constant at 600 rpm during the reaction. No pressure was required during the reaction, and the pressure naturally decreased. After the reaction was completed, a homogeneous reaction liquid was obtained, which contained liquid perfluoroacetyl fluoride. (3) The homogeneous reaction solution containing perfluoroethoxypropionyl fluoride generated is discharged through a bottom valve. Its composition includes perfluoroethoxypropionyl fluoride (the selectivity of perfluoroethoxypropionyl fluoride was measured to be 99.6%). The final product, pure perfluoroethoxypropionyl fluoride (purity of 99.8%), is obtained by distillation (distillation pressure is atmospheric pressure, distillation temperature is 40 °C). Its NMR spectrum is shown in the figure below. Figure 1 (As shown).

[0024] Example 2 (1) In a 5L pressure vessel, add 43 g KF, 1545 g diethylene glycol dimethyl ether and 246 g trifluorotoluene (moisture content ≤100 ppm), cool to -20℃, start stirring, and stir at 400 rpm for 10 min for pretreatment activation; (2) Then, 600 g of gaseous perfluoroformyl fluoride was added to the reactor at one time, and 754 g of gaseous hexafluoropropylene oxide HFPO was introduced. The reaction was carried out at -20℃ for 240 min. The stirring speed was kept constant at 400 rpm during the reaction. No pressure was required during the reaction, and the pressure naturally decreased. After the reaction was completed, a homogeneous reaction liquid was obtained, which contained liquid perfluorooxopropionyl fluoride. (3) The homogeneous reaction liquid containing perfluoromethoxypropionyl fluoride generated is discharged through the bottom valve. Its composition includes perfluoromethoxypropionyl fluoride (the selectivity of perfluoromethoxypropionyl fluoride was measured to be 99.7%). The final product, pure perfluoromethoxypropionyl fluoride (purity of 99.8%), is obtained by distillation (distillation pressure is atmospheric pressure, distillation temperature is 20 °C).

[0025] Example 3 (1) In a 5L pressure vessel, add 126 g KF, 425 g diethylene glycol dimethyl ether and 2036 g m-difluorotoluene (moisture content ≤100 ppm), cool to -15℃, start stirring, and stir at 1000 rpm for 15 min for pretreatment activation; (2) Then, 1000 g of gaseous perfluoropropionyl fluoride was added to the reactor at one time, and then 1000 g of gaseous hexafluoropropylene oxide HFPO was introduced. The reaction was carried out at -15℃ for 180 min. The stirring speed was kept constant at 1000 rpm during the reaction. No pressure was required during the reaction, and the pressure naturally decreased. After the reaction was completed, a homogeneous reaction liquid was obtained, which contained liquid perfluoropropionyl fluoride. (3) The homogeneous reaction liquid containing perfluoropropoxypropionyl fluoride generated is discharged through the bottom valve. Its composition includes perfluoropropoxypropionyl fluoride (the selectivity of perfluoropropoxypropionyl fluoride was measured to be 99.4%). The final product, pure perfluoropropoxypropionyl fluoride (purity of 99.6%), is obtained by distillation (distillation pressure is atmospheric pressure, distillation temperature is 70 °C).

[0026] Example 4 (1) In a 5L pressure vessel, add 366 g KF, 1111 g diethylene glycol dimethyl ether and 1419 g m-difluorotoluene (moisture content ≤100 ppm), cool to -20℃, start stirring, and stir at 1500 rpm for 10 min for pretreatment activation; (2) Then, 543 g of gaseous perfluoroformyl fluoride was added to the reactor at one time, and 1050 g of gaseous hexafluoropropylene oxide HFPO was introduced. The reaction was carried out at -20℃ for 360 min. The stirring speed was kept constant at 1500 rpm during the reaction. No pressure was required during the reaction, and the pressure naturally decreased. After the reaction was completed, a homogeneous reaction liquid was obtained, which contained liquid perfluorooxopropionyl fluoride. (3) The homogeneous reaction liquid containing perfluorooxypropionyl fluoride generated is discharged through the bottom valve. Its composition includes perfluoromethoxypropionyl fluoride (the selectivity of perfluoromethoxypropionyl fluoride was measured to be 99.4%). The final product, pure perfluoromethoxypropionyl fluoride (purity of 99.6%), is obtained by distillation (distillation pressure is atmospheric pressure, distillation temperature is 20 °C).

[0027] Example 5 (1) In a 5L pressure vessel, add 8.73g KF, 730g diethylene glycol dimethyl ether and 2331g m-difluorotoluene (moisture content ≤100 ppm), cool to 0℃, start stirring, and stir at 1000 rpm for 30 min for pretreatment activation; (2) Then, 628 g of gaseous perfluoroacetyl fluoride was added to the reactor at one time, and 500 g of gaseous hexafluoropropylene oxide HFPO was introduced. The reaction was carried out at 0℃ for 200 min. The stirring speed was kept constant at 1000 rpm during the reaction. No pressure was required during the reaction, and the pressure naturally decreased. After the reaction was completed, a homogeneous reaction liquid was obtained, which contained liquid perfluoroacetyl fluoride. (3) The homogeneous reaction liquid containing perfluoroethoxypropionyl fluoride generated is discharged through the bottom valve. Its composition includes perfluoroethoxypropionyl fluoride (the selectivity of perfluoroethoxypropionyl fluoride was measured to be 99.5%). The final product, pure perfluoroethoxypropionyl fluoride (purity of 99.7%), is obtained by distillation (distillation pressure is atmospheric pressure, distillation temperature is 40 °C).

[0028] Example 6 (1) In a 5L pressure vessel, add 559 g KF, 510 g diethylene glycol dimethyl ether and 2036 g m-difluorotoluene (moisture content ≤100 ppm), cool to -40℃, start stirring, and stir at 200 rpm for 20 min for pretreatment activation; (2) Then, 1500 g of gaseous perfluoropropionyl fluoride was added to the reactor at one time, and then 1500 g of gaseous hexafluoropropylene oxide HFPO was introduced. The reaction was carried out at -40℃ for 260 min. The stirring speed was kept constant at 200 rpm during the reaction. No pressure was required during the reaction, and the pressure naturally decreased. After the reaction was completed, a homogeneous reaction liquid was obtained, which contained liquid perfluoropropionyl fluoride. (3) The homogeneous reaction liquid containing perfluoropropoxypropionyl fluoride generated is discharged through the bottom valve. Its composition includes perfluoropropoxypropionyl fluoride (the selectivity of perfluoropropoxypropionyl fluoride was measured to be 99.4%). The final product, pure perfluoropropoxypropionyl fluoride (purity of 99.8%), is obtained by distillation (distillation pressure is atmospheric pressure, distillation temperature is 70 °C).

[0029] Comparative Example 1 (1) In a 5L pressure vessel, add 86 g KF and 1700 g diethylene glycol dimethyl ether (moisture content ≤100 ppm), cool to -30℃, start stirring, and stir at 600 rpm for 40 min for pretreatment activation; (2) Subsequently, 800 g of gaseous perfluoroacetyl fluoride was added to the reactor at one time, and then 926 g of gaseous hexafluoropropylene oxide HFPO was introduced. The reaction was carried out at -30℃ for 300 min to obtain a heterogeneous layered reaction liquid. The lower layer of the reaction liquid contained liquid perfluorooxypropionyl fluoride. (3) The homogeneous reaction liquid containing perfluorooxypropionyl fluoride generated is discharged through the bottom valve. Its composition includes perfluoromethoxypropionyl fluoride (the selectivity of the target product perfluoromethoxypropionyl fluoride was measured to be 92.5%, and the selectivity of the by-product perfluoromethoxyheptanoyl fluoride was 7.6%). The final product perfluoromethoxypropionyl fluoride (purity of 93.5%) is obtained by distillation (distillation pressure is atmospheric pressure, distillation temperature is 40 °C).

[0030] Comparative Example 2 (1) In a 5L pressure vessel, add 31 g KF and 2000 g diethylene glycol dimethyl ether (moisture content ≤100 ppm), cool to -20℃, start stirring, and stir at 1000 rpm for 30 min for pretreatment activation; (2) Then, 437 g of gaseous perfluoroacetyl fluoride was added to the reactor at one time, and 1000 g of gaseous hexafluoropropylene oxide HFPO was introduced. The reaction was carried out at -20℃ for 200 min to obtain a heterogeneous layered reaction solution. The lower layer of the reaction solution contained liquid perfluorooxypropionyl fluoride. (3) The homogeneous reaction liquid containing perfluorooxopropionyl fluoride generated is discharged through the bottom valve. Its composition includes perfluoroethoxypropionyl fluoride (the selectivity of the target product perfluoroethoxypropionyl fluoride was measured to be 94.1%, and the selectivity of the by-product perfluoroethoxyheptanoyl fluoride was 5.6%). The final product perfluoroethoxypropionyl fluoride (purity of 95.1%) is obtained by distillation (distillation pressure is atmospheric pressure, distillation temperature is 40 °C).

[0031] Comparative Example 3 (1) In a 5L pressure vessel, add 76 g KF and 1000 g m-difluorotoluene (moisture content ≤100 ppm), cool to -10℃, start stirring, and stir at 1500 rpm for 20 min for pretreatment activation; (2) Then, 1100 g of gaseous perfluoropropionyl fluoride was added to the reactor at one time, and then 1100 g of gaseous hexafluoropropylene oxide HFPO was introduced. The reaction was carried out at -10℃ for 260 min to obtain a heterogeneous layered reaction solution. The lower layer of the reaction solution contained liquid perfluoropropionyl fluoride. (3) The homogeneous reaction liquid containing perfluoropropionyl fluoride is discharged through the bottom valve. Its composition includes perfluoropropoxypropionyl fluoride (the selectivity of the target product perfluoropropoxypropionyl fluoride was measured to be 88.4%, the selectivity of perfluoropropoxyheptyl fluoride was 9.6%, and the selectivity of perfluoropropoxydecyl fluoride was 1.1%). The final product perfluoropropoxypropionyl fluoride (purity of 91.1%) is obtained by distillation (distillation pressure is atmospheric pressure, distillation temperature is 70 °C).

[0032] Sample Analysis In summary, comparative examples 1-3 show that the selectivity of the target product is low and the number of byproducts is high when only m-difluorotoluene or diethylene glycol dimethyl ether is present. This is because m-difluorotoluene has weak polarity and is prone to chain propagation, while diethylene glycol dimethyl ether has slightly stronger polarity but poorer selectivity and product yield. The mixed solvent system formed by mixing m-difluorotoluene and diethylene glycol dimethyl ether has a polarity more suitable for monomer formation and higher selectivity, with a selectivity of ≥99.4% for perfluorooxopropionyl fluoride and a purity of ≥99.4%. This system can prepare perfluorooxopropionyl fluoride with high selectivity and high purity.

[0033] The embodiments described above provide a detailed explanation of the technical solutions of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions, or similar substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing perfluorooxopropionyl fluoride with high selectivity and high purity, characterized in that, Includes the following steps: (1) Add a mixture of fluorinated benzene solvent and ether solvent, and alkali metal fluoride catalyst to the reactor, and stir at -40 to 0℃ for 10 to 30 min for pretreatment activation; (2) Gaseous perfluoroacetyl fluoride and gaseous hexafluoropropylene oxide are introduced into a reaction vessel to carry out a ring-opening reaction to obtain a reaction solution containing liquid perfluoroacetyl fluoride. (3) The reaction solution obtained in step (2) is distilled to obtain perfluorooxopropionyl fluoride, the general structural formula of which is XO-CF(CF3)CFO, where X is CF3-, CF3CF2- or CF3CF2CF2-. The fluorinated benzene solvents are m-difluorotoluene and / or trifluorotoluene; the ether solvents include ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether or tetraethylene glycol dimethyl ether, and the molar ratio of the fluorinated benzene solvents to the ether solvents is 0.1 to 3:

1.

2. The method for preparing perfluorooxopropionyl fluoride with high selectivity and high purity according to claim 1, characterized in that, The fluorinated benzene solvent is m-difluorotoluene or trifluorotoluene, and the ether solvent is diethylene glycol dimethyl ether or triethylene glycol dimethyl ether. The molar ratio of the fluorinated benzene solvent to the ether solvent is 0.8 to 1.5:

1.

3. The method for preparing perfluorooxopropionyl fluoride with high selectivity and high purity according to claim 1, characterized in that, Alkali metal fluorides are at least one of potassium fluoride, calcium fluoride, cesium fluoride, rubidium fluoride, and silver fluoride.

4. The method for preparing perfluorooxopropionyl fluoride with high selectivity and high purity according to claim 1, characterized in that, Perfluoroacyl fluoride is perfluoroformyl fluoride CF2O, perfluoroacetyl fluoride CF3CFO, or perfluoropropionyl fluoride CF3CF2CFO.

5. The method for preparing perfluorooxopropionyl fluoride with high selectivity and high purity according to claim 1, characterized in that, In step (2), the molar ratio of gaseous perfluoroacyl fluoride to gaseous hexafluoropropylene oxide is 1 to 2:

1.

6. The method for preparing perfluorooxopropionyl fluoride with high selectivity and high purity according to claim 1, characterized in that, First, gaseous perfluoroacyl fluoride is introduced into the reactor, followed by gaseous hexafluoropropylene oxide. Stirring is used during the ring-opening reaction. The ring-opening reaction temperature is -40 to 0℃, the stirring speed is 200 to 2000 rpm, and the reaction time is 180 to 360 min.

7. The method for preparing perfluorooxopropionyl fluoride with high selectivity and high purity according to claim 1, characterized in that, The mass ratio of alkali metal fluoride catalyst to perfluoroacyl fluoride is 0.01 to 1:1, based on molar mass.

8. The method for preparing perfluorooxopropionyl fluoride with high selectivity and high purity according to claim 1, characterized in that, The distillation conditions are: distillation pressure is atmospheric pressure, and distillation temperature is 0 to 70°C.

9. The method for preparing perfluorooxopropionyl fluoride with high selectivity and high purity according to claim 1, characterized in that, The selectivity of perfluorooxypropionyl fluoride in the ring-opening polymerization stage is ≥92%, and the purity of perfluorooxypropionyl fluoride obtained after distillation is ≥99.4%.

10. The method for preparing perfluorooxopropionyl fluoride with high selectivity and high purity according to any one of claims 1-9 is used in the synthesis of perfluoroalkyl vinyl ethers or perfluoropolyethers.

Images