An environment-friendly hydrofluoroether compound and its preparation method

Abstract

The present invention discloses an environmentally friendly hydrofluoroether compound and a preparation method thereof. The method comprises: dissolving a terminal-silicon modified catalyst in an organic solvent and adding the solution into a high-pressure reaction kettle that has been deoxygenated and dehydrated, and then adding a polyfluoroolefin; continuously introducing a hydroxy-containing organic compound, a polyfluoroolefin and an organic solvent at a constant speed, and then carrying out a reaction at a constant temperature. After the reaction is completed, the temperature is decreased; the obtained material is fractionated to obtain the environmentally friendly hydrofluoroether compound. The preparation method of the present invention has a stable, rapid and easy-to-control reaction, high efficiency, good selectivity, the product purity exceeding 99.75%, the selectivity exceeding 97.0%, and at the same time, the materials can be recycled, the catalyst can be recycled for more than 30 times, the separation is simple, and the boiling points and other properties of the solvent and the catalyst, and the solvent and the product have large differences, making it easier to recycle. In addition, the method of the present invention has high comprehensive efficiency, simple operation and low production cost, and is more suitable for the development trend of contemporary industry.

Description

Technical Field

[0001] The present invention relates to the technical field of preparation of fluorine-containing new materials, and particularly to an environmentally friendly hydrofluoroether compound and a preparation method thereof. Background Art

[0002] CFCs (chlorofluorocarbons) are substances with good chemical stability that were first applied in the refrigeration and cleaning industries. However, they are also one of the main substances that damage the ozone layer, causing the greenhouse effect and global warming, and directly leading to an increase in ultraviolet radiation entering the atmosphere, which poses a considerable hazard to humans, animals, and plants. In recent years, seeking global symbiosis and green industry at home and abroad, a lot of energy has been devoted to the research and production of CFCs substitutes. Among them, hydrofluoroethers have become ideal substances for modern industry because they do not contain ozone-depleting elements such as chlorine and bromine. They are heteroatom compounds composed of elements such as C, H, F, and O, and have the advantages of being non-toxic, non-flammable, stable, and having very low ODP and GWP values.

[0003] Hydrofluoroether compounds have multiple synthesis routes, such as fluorination of ethers with fluorine gas or high-valent metal fluoride compounds, electrochemical fluorination of ethers, substitution reactions of alcohols with halogenated hydrocarbons, addition reactions of alcohols with fluorinated olefins, etc. In the ether fluorination method, although F2 has the highest activity, its selectivity is the worst. Metal fluoride fluorination has a high yield but is expensive, which also limits its use. The electrochemical method can synthesize isolated hydrofluoroethers, but it consumes a large amount of electricity and generally requires a large amount of anhydrous hydrogen fluoride during the process. The products contain a large number of isomers with similar properties and are almost impossible to effectively separate, so it is not suitable for industrial applications. The substitution reaction of alcohols with halogenated hydrocarbons has relatively harsh conditions such as high temperature and high pressure, and has a low yield and a long cycle, and has basically been phased out. The addition reaction of alcohols with fluorinated olefins is relatively simple in operation and has mild reaction conditions, and is currently a synthetic preparation method with industrialization prospects.

[0004] For example, Chinese Patent CN112142572A discloses a continuous process device and method for synthesizing hydrofluoroethers. Raw material alcohol containing a catalyst and tetrafluoroethylene are continuously introduced into a reaction kettle for reaction, and the continuous discharge is separated through an evaporator. The product and the raw materials enter a distillation system for further separation. The separated raw materials are returned to the raw material tank, and the remaining solvent is returned for reuse. The conversion rate of the raw material alcohol is 80-93%. A large amount of raw material alcohol is contained in the product of this process, and the separation is difficult.

[0005] For another example, Chinese Patent Application CN113929562A discloses a method for preparing fluoroether, which reacts an alcohol or a phenol with a fluoroolefin in a solvent to produce fluoroether. The molar ratio of the fluoroolefin to the alcohol or the phenol is 0.8 - 1.2:1, the molar ratio of the catalyst to the alcohol or the phenol is 0.03 - 0.1:1, the mass ratio of the solvent to the alcohol or the phenol is 0.5 - 4:1, and 50 - 100% of the molar amount of the alcohol or the phenol is added continuously after the start of the reaction. However, this method cannot avoid the generation of vinyl ether, and it is not easy to separate. The loss of the catalyst is large and it is basically not recyclable. In addition, the solubility of the catalyst is limited, which limits the homogeneity of the reaction and is also a factor leading to side reactions.

[0006] The synthesis and preparation methods of the prior art have problems such as low efficiency, poor selectivity, generation of by-products such as vinyl ether, resulting in poor batch - to - batch stability, high production cost, and difficulty in separating the product materials, and it is difficult to meet the requirements of contemporary industrial production. Summary of the Invention

[0007] In view of the technical problems existing in the prior art, the present invention provides a method for preparing an environmentally friendly fluoroether compound, which solves the problems of long cycle and low yield in the prior art, has higher selectivity, fewer by - products and is easier to separate, the reaction process is stable and can be recycled, the cost is reduced, and it is beneficial to realize industrial production. Specifically, the present invention includes the following content.

[0008] In the first aspect of the present invention, there is provided a method for preparing an environmentally friendly hydrofluoroether compound, which comprises:

[0009] (1) Dissolve the terminal - silicon - modified catalyst in an organic solvent, then add it to a high - pressure reaction kettle that has been deoxygenated and dehydrated, and then add the polyfluoroolefin;

[0010] (2) Continuously introduce the hydroxy - containing organic compound, the polyfluoroolefin and the organic solvent at a constant speed, and then keep the reaction at a constant temperature. After the reaction is completed, cool down;

[0011] (3) After the material obtained in step (2) is fractionated, the environmentally friendly hydrofluoroether compound is obtained.

[0012] In some embodiments, for the method for preparing the environmentally friendly hydrofluoroether compound according to the present invention, in step (1), the terminal - silicon - modified catalyst is 0.5 - 8 parts by weight, the organic solvent is 30 - 50 parts by weight, and the polyfluoroolefin is 25 - 50 parts by weight.

[0013] In some embodiments, for the method for preparing the environmentally friendly hydrofluoroether compound according to the present invention, in step (2), the hydroxy - containing organic compound is 40 - 80 parts by weight.

[0014] In certain embodiments, for the method for preparing an environmentally friendly hydrofluoroether compound according to the present invention, in step (2), the feeding rate ratio of the hydroxy-containing organic compound, the polyfluoroolefin, and the organic solvent is 1:1 - 1.5:0.8 - 1.2.

[0015] In certain embodiments, for the method for preparing an environmentally friendly hydrofluoroether compound according to the present invention, in step (2), the reaction temperature is 40 - 90 °C, and the reaction time is 1 - 2 h.

[0016] In certain embodiments, for the method for preparing an environmentally friendly hydrofluoroether compound according to the present invention, the hydroxy-containing organic compound includes at least one of trifluoroethanol, trifluoropropanol, pentafluoropropanol, and octafluoropentanol.

[0017] In certain embodiments, for the method for preparing an environmentally friendly hydrofluoroether compound according to the present invention, the terminal-silicon-modified catalyst is a modified basic ionic compound having the structure shown in the following formula (I):

[0018]

[0019] Wherein, the RSi group is a terminal vinyl silicone oil group with a molecular weight Mn of 400 - 1200, Rc is a straight-chain alkyl group with no more than 4 carbon atoms, and R⁻ is selected from carbonate, acetate, or hydroxide. Among them, the terminal vinyl silicone oil group has a molecular weight Mn of 400 - 1200, Rc is a straight-chain alkyl group with no more than 4 carbon atoms, and R⁻ is selected from carbonate, acetate, or hydroxide. Preferably, the molecular weight Mn of the terminal vinyl silicone oil group is 400 - 1000, such as 400, 600, 800, 1000, Rc is a straight-chain alkyl group with no more than 4 carbon atoms, preferably no more than 3 carbon atoms, such as a straight-chain alkyl group with 1, 2, or 3 carbon atoms.

[0020] In certain embodiments, for the method for preparing an environmentally friendly hydrofluoroether compound according to the present invention, the organic solvent includes at least one of N,N-dimethylformamide, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dimethyl sulfoxide, or any combination thereof.

[0021] In certain embodiments, for the method for preparing an environmentally friendly hydrofluoroether compound according to the present invention, the polyfluoroolefin includes at least one of trifluoroethylene, tetrafluoroethylene, hexafluoropropene, vinylidene fluoride, hexafluoropropene, and trichlorotrifluoroethylene.

[0022] In a second aspect of the present invention, there is provided an environmentally friendly hydrofluoroether compound obtained by the method according to the first aspect.

[0023] The beneficial effects of the present invention include:

[0024] (1) The reaction is stable, rapid, easy to control, highly efficient, with good selectivity. The purity of the product exceeds 99.75%, and the selectivity exceeds 97.0%.

[0025] (2) The materials can be recycled, and the catalyst can be recycled for more than 30 times. The separation is simple. There are large differences in properties such as the boiling points between the solvent and the catalyst, and between the solvent and the product, making it easier to recycle.

[0026] (3) The overall efficiency is high, the operation is simple, and the production cost is low, making it more suitable for the development trend of contemporary industry. Description of the Drawings

[0027] Figure 1 The infrared spectrum of the product 1,1,2,2 - tetrafluoroethyl - 2,2,2 - trifluoroethyl ether is exemplarily shown. Detailed Embodiments

[0028] The various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention.

[0029] It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that the upper and lower limits of the range and each intermediate value between them are specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0030] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail. Unless otherwise specified, "%" is a weight - based percentage.

[0031] Preparation Method of Environment - Friendly Fluoroether Compound

[0032] In the present invention, the preparation method of the environmentally friendly fluoroether compound is carried out in a stainless steel high-pressure reactor after water and oxygen are removed. Removing water and oxygen means that the amount of oxygen and water before the reaction is at a relatively low level or basically free of oxygen and water. Preferably, the amount of oxygen is less than 0.05%, more preferably less than 0.01%. The water content ≤ 20 ppm, preferably the content ≤ 10 ppm, more preferably the content ≤ 5 ppm.

[0033] In the method of the present invention, it can be carried out according to the process of first adding part of the bottom material and part of the raw material polyfluoroolefin, and then continuously adding a certain proportion of polyfluoroolefin, solvent and hydroxy compound. Ensuring that the material ratio in the overall reaction system remains relatively stable can promote the smoothness of the reaction, make the selectivity of the reaction better, and the subsequent reaction consumes most of the remaining raw materials, so the cost is saved, and the reaction rate in the later stage of the reaction will not decrease with the reduction of the reactants, nor will it increase significantly due to the increase in the amount of catalyst. Therefore, the process of the present invention (including raw material ratio, feed rate ratio, reaction time and temperature, etc.) helps the reaction to be stable, thus ensuring the normal reaction parallelism and good stability between batches.

[0034] In step (1) of the present invention, 0.5 - 8 parts by weight of the terminal-silicon modified catalyst, preferably 0.8 - 6 parts by weight, more preferably 0.9 - 5 parts by weight, such as 0.9, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 parts by weight or any part by weight within the above numerical range of the terminal-silicon modified catalyst is dissolved in 30 - 50 parts by weight of an organic solvent. The organic solvent is preferably 32 - 50 parts by weight, more preferably 34 - 50 parts by weight, such as 34, 36, 38, 40, 42, 44, 46, 48, 50 parts by weight or any part by weight within the above numerical range of the organic solvent. Then 25 - 50 parts by weight of polyfluoroolefin is added into the reaction kettle. The polyfluoroolefin is preferably 28 - 50 parts by weight, such as 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50 parts by weight or any part by weight within the above numerical range of the polyfluoroolefin.

[0035] In the present invention, the terminal-silicon modified catalyst is a modified basic ionic compound, which has the structure shown in the following formula (I):

[0036]

[0037] The terminal-silicon modified catalyst of the present invention can be synthesized by known procedures or obtained from known products, but is preferably prepared by the following steps: reacting a haloalkane with a hydrocarbyl-substituted imidazole in the dark at 50-90 °C, adding an organic solvent for extraction to obtain an imidazole compound with hydrocarbyl organic halogen substitution, then adding a low molecular weight alcohol, adding a hydrocarbyl silicone oil and azobisisobutyronitrile dissolved in an organic solvent at 50-90 °C, and after completion of the reaction, adding an alkaline solution to obtain the terminal-silicon modified catalyst. Preferably, taking 1-bromobutane as the bromoalkane and 800 as the Mn of the terminal active vinyl silicone oil as an example, 1-bromobutane and vinylimidazole are reacted in a flask equipped with a condensation reflux device under stirring in the dark at 70 °C for 24 h, cooled to room temperature, and ethyl acetate is added for rinsing and extraction to obtain the product vinylbutylimidazole bromide. Vinylbutylimidazole bromide and isopropanol are added to the flask, the temperature is raised to 65 °C, and the terminal active vinyl silicone oil and azobisisobutyronitrile dissolved in acetone are added dropwise within 2 h, and then the reaction is continued for 2 h and then cooled, and sodium hydroxide is added and stirred, and after rinsing with ethanol, the terminal-silicon modified catalyst is obtained.

[0038] First, the bromoalkane reacts with vinylimidazole to form vinylalkylimidazole bromide, then it adds with the terminal active vinyl silicone oil to form terminal-silicon bromoalkylimidazolium salt, and then reacts with an alkaline solution to form the terminal-silicon modified catalyst of the present invention. Its synthesis process can be expressed as (where R- takes hydroxide as an example):

[0039]

[0040] In the present invention, the terminal-silicon modified catalyst is an imidazole-based catalyst modified with terminal-silicon groups. Its apparent activation energy is lower than that of general alkali metal hydroxide catalysts, the reaction conditions are milder, the dosage adjustment range is wider, it has excellent solubility and compatibility with the reaction solvent and each monomer used in the preparation method of the present invention, can be quickly and stably dispersed, the area of contacting and capturing monomers in the reaction is increased, the homogeneous system makes the reaction more stable and easy to control, and there will be no situation where the concentration at a certain site is too high due to poor solubility and the reaction is too fast, thereby reducing the possibility of isomerization and also reducing the probability of other side reactions such as enol etherification reactions. In addition, the terminal-silicon modified catalyst of the present invention has certain properties of pseudo-dissociated protons and forming hydrogen bonds, which also improves the selectivity of the reaction system.

[0041] The catalyst of the present invention is easier to separate from the product, solvent and other materials after end-silicon modification. The purity of the catalytic reaction product recycled more than 30 times reaches more than 99.7%, and it can be completely recovered, for example, by simple distillation and washing. To ensure the synergistic effect of the catalyst's performance, compatibility and selectivity, the RSi group is an end-vinyl silicone oil group with a molecular weight Mn of 400-1200, Rc is a straight-chain alkyl group with no more than 4 carbon atoms, and R- is one of carbonate, acetate and hydroxide. Preferably, the molecular weight of RSi is 400-800 and R- is hydroxide.

[0042] In the present invention, non-limiting examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, etc. The alkyl group can be optionally substituted. Non-limiting examples of the substituted alkyl group include hydroxymethyl, chloromethyl, trifluoromethyl, aminomethyl, 1-chloroethyl, 2-hydroxyethyl, 1,2-difluoroethyl, 3-carboxypropyl, etc.

[0043] In the present invention, the polyfluoroolefin in step (1) includes but is not limited to tetrafluoroethylene and hexafluoropropylene.

[0044] Any organic solvent that does not affect the compatibility of the catalyst and monomer of the present invention and does not produce adverse effects on the reaction can be used as the solvent of the present invention, and a polar solvent is preferably selected. Examples of the polar solvent include but are not limited to any one or any mixture of N,N-dimethylformamide, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and dimethyl sulfoxide. The preferred solvent is any one or any mixture of diethylene glycol dimethyl ether and tetraethylene glycol dimethyl ether.

[0045] In step (2) of the present invention, a total of 40-80 parts by weight of the hydroxy-containing organic compound is continuously introduced for 2-8 hours, preferably 45-75 parts by weight, such as 45, 50, 55, 60, 65, 70, 75 parts by weight. At the same time, polyfluoroolefin and organic solvent are continuously introduced. The feeding rates of the three types of materials are: hydroxy-containing organic compound: polyfluoroolefin: solvent = 1:1-1.5:0.8-1.2, and more preferably 1:1-1.4:0.8-1.1, and further preferably 1:1-1.3:0.8-1.0.

[0046] In step (2), start stirring and keep the temperature at 40-90 °C for reaction, more preferably 45-90 °C, such as 45 °C, 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, 85 °C, 90 °C. After the addition is completed, react for another 1-2 hours and then cool down. The reaction time is preferably 1.2-1.8 hours. Unless otherwise specified, cooling down means reducing the temperature to room temperature.

[0047] In step (2) of the present invention, the hydroxy-containing organic compound is selected from at least one of trifluoroethanol, trifluoropropanol, pentafluoropropanol, and octafluoropentanol. The polyfluoroolefin is selected from at least one of tetrafluoroethylene and hexafluoropropylene. The boiling point of the hydrofluoroether is determined according to the use environment and requirements. In terms of the application scenario of the product of the present invention and the reaction efficiency, the hydroxy-containing compound is preferably at least one of trifluoroethanol and trifluoropropanol, and the polyfluoroolefin is preferably tetrafluoroethylene.

[0048] In step (3), the discharged material is subjected to fractional separation to obtain the environmentally friendly fluoroether compound of the present invention. The fractional separation process can adopt separation methods known in the art, such as rectification or washing, and is not particularly limited thereto.

[0049] Unless otherwise specified, the above-mentioned raw materials referred to in the present invention can be prepared by known methods or obtained as commercially available products.

[0050] Those skilled in the art should understand that before and after the above steps (1)-(3), or between any of these steps, other steps or operations may also be included, such as further optimizing and / or improving the method described in the present invention.

[0051] Environmentally friendly hydrofluoroether compound

[0052] The present invention further provides an environmentally friendly hydrofluoroether compound, which is prepared by the above method of the present invention. The structure of the terminal silicon-modified catalyst and the environmentally friendly hydrofluoroether compound can be confirmed and further characterized by methods known in the art, such as confirming and characterizing the structure by infrared spectroscopy.

[0053] Examples 1-8

[0054] This example is a preparation process of an environmentally friendly hydrofluoroether compound, which is specifically as follows:

[0055] (1) Dissolve the terminal silicon-modified catalyst in an organic solvent and then add it to a high-pressure reaction kettle that has been deoxygenated and dehydrated, and then add the polyfluoroolefin;

[0056] (2) Continuously introduce the hydroxy-containing organic compound, polyfluoroolefin, and organic solvent at a constant speed, and then maintain the reaction at a constant temperature. After the reaction is completed, cool down;

[0057] (3) Subject the material obtained in step (2) to fractional separation to obtain the environmentally friendly hydrofluoroether compound.

[0058] The processes and formulations of Examples 1-8 of the present invention are specifically shown in the following table. The preparation method of the terminal silicon-modified catalyst is as follows, and other raw and auxiliary materials, etc. are all purchased externally.

[0059] Taking 1-bromobutane as the bromoalkyl group and 800 as the Mn of the terminal active vinyl silicone oil in the terminal-silicon-modified catalyst as an example, 1-bromobutane and vinylimidazole were placed in a flask equipped with a condensation reflux device and reacted under stirring in the dark at 70 °C for 24 h. After cooling to room temperature, ethyl acetate was added for rinsing and extraction to obtain the product vinylbutylimidazole bromide.

[0060] Vinylbutylimidazole bromide and isopropanol were added to the flask, and the temperature was raised to 65 °C. The terminal active vinyl silicone oil and azobisisobutyronitrile dissolved in acetone were added dropwise within 2 h, and then the reaction was continued for 2 h followed by cooling. Sodium hydroxide was added and stirred, and then rinsed with ethanol to obtain the terminal-silicon-modified catalyst.

[0061] Table 1

[0062]

[0063]

[0064]

[0065] 2. Product analysis: Fourier transform infrared spectroscopy (FT-IR) was determined using a Nicolet 6700 Fourier transform infrared spectrometer (germanium crystal ATR total reflection) from Thermo Fisher Scientific, USA.

[0066] Purity analysis: Determined by gas chromatography, with the capillary column temperature at 150 °C, the vaporization chamber temperature at 200 °C, the detector temperature at 250 °C, using high-purity nitrogen as the carrier gas, and the detector being a flame ionization detector.

[0067] 3. Results

[0068] The infrared spectrum of one of the products, 1,1,2,2-tetrafluoroethyl 2,2,2-trifluoroethyl ether, in the present invention is as Figure 1 shown.

[0069] The product purity, selectivity, reaction phenomenon, product purity after multiple uses of the catalyst, and catalytic selectivity results are shown in Table 2.

[0070] As can be seen from Table 2, in the synthesis process of an environmentally friendly fluoroether compound of the present invention, both the product purity and selectivity are significantly improved compared to the synthesis using a conventional base catalyst. Moreover, the catalytic effect of the catalyst after 30 cycles of reuse can still meet the indicators of the present invention, while the base catalyst can hardly be reused, and there is an obvious decline in the catalytic effect and cycle reuse without terminal-silicon modification, indicating that the terminal-silicon-modified catalyst of the present invention has good stability and cycle use performance.

[0071] Table 2

[0072]

[0073] Comparative Examples 1-2

[0074] In Comparative Examples 1-2, an alkaline catalyst was used respectively. Only for example, reactions were carried out using potassium hydroxide as the catalyst and a catalyst without terminal silicon modification. The results are shown in Table 2.

[0075] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the disclosed exemplary embodiments. Various adjustments or changes can be made to the exemplary embodiments of the present invention specification without departing from the scope or spirit of the present invention. The scope of the claims should be interpreted in the broadest manner to cover all modifications and equivalent structures and functions.

Claims

1. A preparation method of an environmentally friendly hydrofluoroether compound, characterized in that, Comprising: (1) Dissolve the end-silicon modified catalyst in an organic solvent and then add it to a high-pressure reactor that has been deoxygenated and dehydrated, and then add the polyfluoroolefin; (2) Continuously introduce the hydroxy-containing organic compound, polyfluoroolefin and organic solvent at a constant rate, and then maintain the reaction at a constant temperature. After the reaction is completed, cool down; (3) After the material obtained in step (2) is fractionated, the environmentally friendly hydrofluoroether compound is obtained; wherein, the hydroxy-containing organic compound is one of trifluoroethanol, trifluoropropanol, pentafluoropropanol, octafluoropentanol, and the end-silicon modified catalyst is a modified basic ionic compound, and the end-silicon modified catalyst is prepared by the following method: The haloalkane reacts with the alkyl-substituted imidazole in the dark at 50 - 90 °C. After adding an organic solvent for extraction, an imidazole compound with alkyl organic halogen substitution is obtained. Then, a low molecular weight alcohol is added, and a hydrocarbon-based silicone oil and azobisisobutyronitrile dissolved in an organic solvent are added at 50 - 90 °C. After the reaction is completed, an alkali solution is added to obtain the terminal silicon-modified catalyst. Among them, the haloalkane is RcBr, where Rc is a straight-chain alkyl group with no more than 4 carbon atoms, and the alkyl-substituted imidazole is , and the hydrocarbon-based silicone oil is . The molecular weight Mn of the RSi group is 400 - 1200, and the alkali solution contains one of carbonate, acetate, and hydroxide.

2. The preparation method of the environment-friendly hydrofluoroether compound according to claim 1, characterized in that, In step (1), the end-silicon modified catalyst is 0.5-8 parts by weight, the organic solvent is 30-50 parts by weight, and the polyfluoroolefin is 25-50 parts by weight.

3. The preparation method of the environment-friendly hydrofluoroether compound according to claim 2, characterized in that, In step (2), the hydroxy-containing organic compound is 40-80 parts by weight.

4. The preparation method of the environmentally friendly hydrofluoroether compound according to claim 3, characterized in that, In step (2), the feeding rate ratio of the hydroxy-containing organic compound, the polyfluoroolefin and the organic solvent is 1:1-1.5:0.8-1.

2.

5. The preparation method of the environmentally friendly hydrofluoroether compound according to claim 4, characterized in that, In step (2), the reaction temperature is 40-90 °C and the reaction time is 1-2 h.

6. The preparation method of the environmentally friendly hydrofluoroether compound according to claim 5, characterized in that, The organic solvent is one or any combination of N,N-dimethylformamide, diethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dimethyl sulfoxide.

7. The preparation method of the environmentally friendly hydrofluoroether compound according to claim 6, characterized in that, The polyfluoroolefin is one of trifluoroethylene, tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, hexafluoropropylene and trichlorotrifluoroethylene.

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