Perfluorocarboxylic acid and preparation method thereof
By leveraging the synergistic effect of a mild oxidant and a catalyst, the problems of low yield and excessive waste in the preparation of perfluorocarboxylic acids have been solved, achieving high-yield and environmentally friendly perfluorocarboxylic acid preparation that is suitable for industrial applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- MINJIANG UNIVERSITY
- Filing Date
- 2023-04-06
- Publication Date
- 2026-04-17
Smart Images
Figure CN121872901A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of fluorine-containing new materials, and in particular to a perfluorocarboxylic acid and its preparation method. Background Technology
[0002] Perfluorocarboxylic acids are a class of compounds in which all hydrogen atoms in the carbon chain are replaced by fluorine atoms. They are mainly used as catalysts for esterification and condensation reactions, and also as reaction solvents, anti-sticking agents, and intermediates in pharmaceuticals and pesticides. Fluorocarboxylic acids can be prepared from corresponding hydrogen-containing acids, anhydrides, esters, acyl chlorides, or acyl fluorides via electrochemical fluorination, or from hydrogen-containing precursors via fluorine gas fluorination. However, these methods all suffer from extremely low yields and complex, difficult-to-separate products. Summary of the Invention
[0003] In view of this, this application provides a perfluorocarboxylic acid and a method for preparing the same, which aims to use a green oxidant to carry out a mild reaction to prepare perfluorocarboxylic acid.
[0004] The embodiments of this application are implemented as follows: A method for preparing a perfluorocarboxylic acid according to this application includes the following steps:
[0005] A solvent, a first compound containing a transition metal element, and a second compound containing a peroxy group are added to a perfluorinated α-olefin monomer, respectively. After mixing, reaction, and distillation, perfluorocarboxylic acid is obtained.
[0006] The transition metal element is selected from at least one of the transition metal elements of group IVB, group VB or group VIB.
[0007] In some embodiments, the mass ratio of the perfluorinated α-olefin monomer, solvent, first compound, and second compound is 100:(40-60):(0.1-0.2):(75-230).
[0008] In some embodiments, the α-olefin monomer of the perfluorinated α-olefin is selected from at least one of 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene.
[0009] In some embodiments, the perfluorinated α-olefin monomer is selected from at least one of perfluorohexylethylene, perfluorobutylethylene, perfluoropentylethylene, and perfluorooctylethylene.
[0010] In some embodiments, the transition metal element is selected from at least one of vanadium, titanium, and molybdenum.
[0011] In some embodiments, the first compound is selected from at least one of acetylacetonate vanadyl, vanadyl acetate, vanadyl sulfate, vanadyl oxalate, vanadyl benzoate, bis(pyridine-2-carboxylic acid) vanadyl, bis(maltol) vanadyl, acetylacetonate titanium, isopropyl titanium, titanium sulfate, titanium oxalate phthalocyanine, titanium oxalate ammonium, bis(2,2,6,6-tetramethyl-3,5-heptanoic acid) titanium oxide, [1,2-phenylene glycol (2-)-O,O'] titanium, and acetylacetonate molybdenum.
[0012] In some embodiments, the second compound is selected from at least one of peroxides such as hydrogen peroxide, sodium peroxide, urea peroxide, peracetic acid, dicumyl peroxide, benzoyl peroxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, and m-chloroperoxybenzoic acid.
[0013] In some embodiments, the reaction temperature is 10–40°C and the reaction time is 6–12 h.
[0014] In some embodiments, the pH of the solvent is 1 to 3; and / or
[0015] The solvent is selected from at least one of trifluoroacetic acid, trifluoropropionic acid, and trifluorobutyric acid.
[0016] In some embodiments, the second compound containing a peroxy group is added to the perfluorinated α-olefin monomer by titration.
[0017] In some embodiments, this application also provides a perfluorocarboxylic acid, which is prepared by the perfluorocarboxylic acid preparation method described above.
[0018] The beneficial effects of this application are as follows:
[0019] This application utilizes a second compound containing a peroxy group and a first compound containing a transition metal element as a catalyst to achieve mild oxidation of perfluorinated α-olefin monomers, yielding perfluorocarboxylic acids in high yield. The raw materials used are green, environmentally friendly, inexpensive, and readily available. The reaction process has low energy consumption and does not generate a large amount of solid waste, making it suitable for industrial production. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 The hydrogen spectrum of perfluoroheptanoic acid prepared in Example 1 of this application;
[0022] Figure 2The fluorine spectrum of perfluoroheptanoic acid prepared in Example 1 of this application;
[0023] Figure 3 The carbon spectrum of perfluoroheptanoic acid prepared in Example 1 of this application;
[0024] Figure 4 The hydrogen spectrum of perfluorovalerate prepared in Example 2 of this application;
[0025] Figure 5 The fluorine spectrum of perfluorovalerate prepared in Example 2 of this application;
[0026] Figure 6 This is the carbon spectrum of perfluorovalerate prepared in Example 2 of this application. Detailed Implementation
[0027] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application. In this application, unless otherwise stated, directional terms such as "upper" and "lower" specifically refer to the drawing directions in the accompanying drawings. In addition, in the description of this application, the term "including" means "including but not limited to". Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and conciseness and should not be construed as a hard limitation on the scope of the present invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single values within that range. For example, it should be assumed that the description of a range from 1 to 6 specifically discloses subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the range referred to.
[0028] The inventors of this application have discovered that perfluoroheptanoic acid is a very important new fluorinated material, mainly used as an emulsifier and dispersant for fluorinated polymers, as well as a leveling agent for inks and coatings. Currently, perfluorooctanoic acid (PFOA) is the main fluorinated emulsifier, but it suffers from bioaggregation and poor degradation. Therefore, C5-C7 perfluoroalkyl carboxylic acids have broad application prospects as alternatives. Fluorinated carboxylic acids can be prepared by electrochemical fluorination of corresponding hydrogen-containing acids, anhydrides, esters, acyl chlorides, or acyl fluorides, or by fluorination of hydrogen-containing precursors with fluorine gas. However, both methods suffer from extremely low yields and complex, difficult-to-separate products. Fluorinated carboxylic acids can also be prepared by oxidation of fluorinated olefins (monoolefins, dienes, cycloolefins, etc.), but these methods require strong oxidants and strong acids, and generate large amounts of solid waste, making them unsuitable for industrial production. In summary, the existing methods for preparing C5-C7 perfluoroalkyl carboxylic acids have the following disadvantages: (1) Using strong oxidizing systems, such as potassium permanganate and concentrated sulfuric acid, the reaction process is highly exothermic, requiring high-performance equipment, resulting in low safety, and generating a large amount of solid waste, making industrial production impossible; (2) Using electrofluorination to prepare perfluorocarboxylic acids results in low yield, requires the use of hydrofluoric acid, requires high-performance equipment, consumes a lot of energy, and causes heavy pollution.
[0029] Therefore, based on the aforementioned shortcomings and problems, this application provides a perfluorocarboxylic acid and a method for its preparation. These will be described in detail below. It should be noted that the order of description of the following examples is not intended to limit the preferred order of the examples.
[0030] This application provides a method for preparing a chitosan porous membrane, which includes the following steps:
[0031] A solvent, a first compound containing a transition metal element, and a second compound containing a peroxy group are added to a perfluorinated α-olefin monomer, respectively. After mixing, reaction, and distillation, perfluorocarboxylic acid is obtained.
[0032] In the preparation method of this application, the second compound containing a peroxide group has a milder reaction temperature compared to traditional strong oxidizing agents, avoiding the problems of exothermic reactions and the generation of large amounts of solid waste during the reaction, thus improving reaction safety and reducing the requirements for reaction equipment. Furthermore, by adding a first compound containing a transition metal element, the transition metal element facilitates the release of active oxygen atoms from the peroxide, enhancing the oxidizing power of the second compound containing the peroxide group, thereby achieving the oxidation of olefin double bonds. In this application, the transition metal element and the peroxide group synergistically improve both the oxidizing power of the second compound and the reaction safety between the raw materials.
[0033] In some embodiments, the transition metal element is selected from at least one transition metal element from Group IVB, Group VB, or Group VIB. It is understood that transition metal elements from Group IVB, Group VB, or Group VIB have a better ability to promote the decomposition of peroxide groups to form more reactive oxygen species.
[0034] In some embodiments, the transition metal element is selected from at least one of vanadium, titanium, and molybdenum.
[0035] Further, the first compound is selected from at least one of acetylacetonate vanadium oxyacetate, vanadium oxyacetate, vanadium oxysulfate, vanadium oxyoxalate, vanadium oxybenzoate, bis(pyridine-2-carboxylic acid) vanadium oxyacetate, bis(maltol) vanadium oxyacetate titanium oxyacetate, isopropyl titanium oxyacetate, titanium oxysulfate, titanium oxyphthalocyanine, titanium oxyoxalate ammonium, bis(2,2,6,6-tetramethyl-3,5-heptanoic acid) titanium oxide, [1,2-phenylene glycol (2-)-O,O'] titanium oxyacetate molybdenum oxyacetate. Among them, the preferred vanadium-containing compounds are vanadium acetylacetonate, vanadium acetate, vanadium sulfate, vanadium oxalate, vanadium benzoate, vanadium bis(pyridine-2-carboxylic acid) vanadium, and vanadium bis(maltol) vanadium, because vanadium has more oxidation states, and the oxidation states in vanadium-containing compounds tend to be high. Vanadium with high oxidation states has higher oxidizing power. Therefore, the above-mentioned vanadium-containing compounds can promote the decomposition of peroxide groups and also undertake part of the oxidation of double bonds, further improving the oxidation effect on olefin double bonds and facilitating the formation of carboxyl groups.
[0036] In some embodiments, the α-olefin monomer in the perfluorinated α-olefin monomer is selected from at least one of 1-pentene, 1-hexene, 1-heptene, and 1-octene. By limiting the type of α-olefin, the number of carbon atoms in the prepared perfluorocarboxylic acid can be easily determined, and the preferred number of carbon atoms is C5 to C7.
[0037] In some embodiments, the perfluorinated α-olefin monomer is selected from at least one of perfluorohexylethylene, perfluorobutylethylene, and perfluoropentylethylene.
[0038] Furthermore, the perfluorocarboxylic acid prepared is selected from at least one of perfluorovaleric acid, perfluorohexanoic acid, and perfluoroheptanoic acid.
[0039] In some embodiments, the mass ratio of the perfluorinated α-olefin monomer, solvent, first compound, and second compound is 100:(40-60):(0.1-0.2):(75-230).
[0040] More preferably, the mass ratio of the perfluorinated α-olefin monomer, solvent, first compound, and second compound is 100:50:(0.1-0.2):(100-200).
[0041] In some embodiments, the mass ratio of the first compound and the second compound is further (0.1 to 0.2):(100 to 200); for example, the mass ratio of the first compound and the second compound is any one or any two of 0.1:100, 0.15:100, 0.2:100, 0.1:150, 0.15:150, 0.2:150, 0.1:200, 0.15:200, 0.2:200.
[0042] In some embodiments, the solvent serves to provide an acidic environment for the reaction. By providing protonated hydrogen, hydrogen peroxide can release reactive oxygen atoms under the action of a catalyst, thereby enhancing the effect of reactive oxygen oxidation.
[0043] In some embodiments, the pH of the solvent is 1 to 3. For example, the pH of the solvent can be any one of 1, 2, or 3.
[0044] In some embodiments, the solvent is selected from at least one of trifluoroacetic acid, trifluoropropionic acid, and trifluorobutyric acid.
[0045] In some embodiments, the second compound is selected from at least one of peroxides such as hydrogen peroxide, sodium peroxide, urea peroxide, peracetic acid, dicumyl peroxide, benzoyl peroxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, and m-chloroperoxybenzoic acid. It is understood that the second compound described above is a substance containing a peroxy group, and under the catalytic action of the first compound, the peroxy group can be promoted to decompose reactive oxygen atoms to oxidize the double bond.
[0046] In some embodiments, the reaction temperature is 10–40°C. For example, the reaction temperature can be any one of 10°C, 25°C, and 40°C, or a range between any two.
[0047] In some embodiments, the reaction time is 6 to 12 hours. For example, the reaction time can be any one of 6 hours, 8 hours, and 12 hours, or a range between any two.
[0048] In some embodiments, the preparation method of this application specifically includes: adding a perfluorinated α-olefin monomer, a solvent, and a first compound containing a transition metal element to a three-necked flask equipped with a mechanical stirrer and a thermometer; slowly adding a second compound containing a peroxy group using a constant pressure dropping funnel; maintaining room temperature using a water bath; continuing stirring at room temperature after the addition is complete; and finally obtaining perfluorocarboxylic acid by distillation.
[0049] In some embodiments, the second compound containing a peroxy group is added to the perfluorinated α-olefin monomer by titration, which can give the second compound containing the peroxy group a better oxidation effect, thereby achieving a better reaction effect.
[0050] To enable those skilled in the art to clearly understand the above-described implementation details and operations, and to demonstrate the significant advancements in the performance of the perfluorocarboxylic acid and its preparation method in the embodiments of this application, the following examples illustrate the above technical solutions.
[0051] Example 1
[0052] 100g of perfluorohexylethylene, 50g of trifluoroacetic acid, and 0.1g of vanadium acetylacetonate were added to a 500ml three-necked flask equipped with a mechanical stirrer and a thermometer. 150g of hydrogen peroxide was slowly added dropwise using a constant pressure dropping funnel. The temperature was maintained at room temperature using a water bath. After the addition was completed, the mixture was stirred at room temperature (25°C) for 6 hours. Finally, 89.4g of perfluoroheptanoic acid was obtained by distillation, with a yield of 85% and a purity of 98%.
[0053] The structure of perfluoroheptanoic acid is:
[0054]
[0055] Combination Figure 1-3 The NMR test results are as follows:
[0056] 1 H NMR (400MHz, Methanol-d4) δ5.17 (s, 1H). 19 F NMR(376MHz, Methanol-d4)δ-82.58(t,J=10.0Hz),-120.35(t,J=12.6Hz),-122.63–-123.22(m) ,-123.88–-124.09(m),-124.19(dd,J=14.0,6.4Hz),-127.50(dddt,J=18.8,11.4,7.7,3.7Hz). 13 C NMR (101MHz, Methanol-d4) δ 159.07 (t, J = 28.2Hz), 121.40 (t, J = 32.8Hz), 118.54 (t, J = 33.0Hz), 115.68 (t, J = 33.1Hz), 114.19–103.16 (m).
[0057] Example 2
[0058] 100g of perfluorobutylethylene, 50g of trifluoroacetic acid, and 0.1g of vanadium acetylacetonate were added to a 500ml three-necked flask equipped with a mechanical stirrer and a thermometer. 230g of hydrogen peroxide was slowly added dropwise using a constant pressure dropping funnel while maintaining room temperature in a water bath. After the addition was completed, the mixture was stirred at room temperature (25°C) for 6 hours. Finally, 86.6g of perfluorovalerate was obtained by distillation, with a yield of 81% and a purity of 97%.
[0059] The structure of perfluorovalerate is:
[0060]
[0061] Combination Figure 4-6 The NMR test results are as follows:
[0062] 1 H NMR (400MHz, Methanol-d4) δ5.80 (s, 1H). 19 F NMR (376MHz, Methanol-d4)δ-82.90(t,J=10.0Hz),-116.45–-122.69(m),-125.26(dtd,J=13.2,6.7,3.0Hz),-127.53(ddq,J=16.5,8.3,4.7,4.0Hz). 13 C NMR (101MHz, Methanol-d4) δ 159.14 (t, J = 28.3Hz), 121.52 (t, J = 33.1Hz), 118.67 (t, J = 33.2Hz), 115.82 (t, J = 33.2Hz), 114.84–103.73 (m).
[0063] Example 3
[0064] 100g of perfluorohexylethylene, 50g of trifluoroacetic acid, and 0.2g of acetylacetone titanium were added to a 500ml three-necked flask equipped with a mechanical stirrer and a thermometer. 150g of hydrogen peroxide was slowly added dropwise using a constant pressure dropping funnel. The temperature was maintained at room temperature using a water bath. After the addition was completed, the mixture was stirred at 20°C for 12 hours. Finally, 82.1g of perfluoroheptanoic acid was obtained by distillation, with a yield of 78% and a purity of 98%.
[0065] Example 4
[0066] 100g of perfluorohexylethylene, 50g of trifluoroacetic acid, and 0.15g of acetylacetone molybdenum oxide were added to a 500ml three-necked flask equipped with a mechanical stirrer and a thermometer. 150g of hydrogen peroxide was slowly added dropwise using a constant pressure dropping funnel. The temperature was maintained at room temperature using a water bath. After the addition was completed, the mixture was stirred at 40℃ for 6 hours. Finally, 77.8g of perfluoroheptanoic acid was obtained by distillation, with a yield of 74% and a purity of 98%.
[0067] Example 5
[0068] 100g of perfluorobutylethylene, 40g of trifluoroacetic acid, and 0.1g of acetylacetone titanium were added to a 500ml three-necked flask equipped with a mechanical stirrer and a thermometer. 200g of hydrogen peroxide was slowly added dropwise using a constant pressure dropping funnel. The temperature was maintained at room temperature using a water bath. After the addition was completed, the mixture was stirred at room temperature (25°C) for 6 hours. Finally, 86.9g of perfluorovalerate was obtained by distillation, with a yield of 81% and a purity of 98%.
[0069] Example 6
[0070] 100g of perfluorobutylethylene, 60g of trifluoroacetic acid, and 0.1g of acetylacetone molybdenum oxide were added to a 500ml three-necked flask equipped with a mechanical stirrer and a thermometer. 180g of hydrogen peroxide was slowly added dropwise using a constant pressure dropping funnel. The temperature was maintained at room temperature using a water bath. After the addition was completed, the mixture was stirred at 10°C for 6 hours. Finally, 75.1g of perfluorovalerate was obtained by distillation, with a yield of 70% and a purity of 98%.
[0071] Example 7
[0072] 100g of perfluorohexylethylene, 50g of trifluoroacetic acid, and 0.1g of vanadium acetylacetonate were added to a 500ml three-necked flask equipped with a mechanical stirrer and a thermometer. 135g of urea peroxide was added slowly in batches. The temperature was maintained at room temperature using a water bath. After the addition was completed, the mixture was stirred at 25°C for 6 hours. Finally, 81.0g of perfluoroheptanoic acid was obtained by distillation, with a yield of 77% and a purity of 98%.
[0073] Example 8
[0074] 100g of perfluorohexylethylene, 50g of trifluoroacetic acid, and 0.1g of vanadium acetylacetonate were added to a 500ml three-necked flask equipped with a mechanical stirrer and a thermometer. Then, 140g of benzoyl peroxide was added slowly in batches. The temperature was maintained at room temperature using a water bath. After the addition was completed, the mixture was stirred at 25°C for 8 hours. Finally, 84.1g of perfluoroheptanoic acid was obtained by distillation, with a yield of 80% and a purity of 98%.
[0075] Example 9
[0076] 100g of perfluorohexylethylene, 50g of trifluoroacetic acid, and 0.1g of vanadium acetylacetonate were added to a 500ml three-necked flask equipped with a mechanical stirrer and a thermometer. 75g of tert-butyl hydrogen peroxide was slowly added dropwise using a constant pressure dropping funnel. The temperature was maintained at room temperature using a water bath. After the addition was completed, the mixture was stirred at 25°C for 10 hours. Finally, 78.9g of perfluoroheptanoic acid was obtained by distillation, with a yield of 75% and a purity of 98%.
[0077] Example 10
[0078] 100g of perfluorohexylethylene, 50g of trifluoroacetic acid, and 0.1g of vanadium acetylacetonate were added to a 500ml three-necked flask equipped with a mechanical stirrer and a thermometer. Then, 100g of m-chloroperoxybenzoyl was slowly added in batches. The temperature was maintained at room temperature using a water bath. After the addition was completed, the mixture was stirred at 25°C for 6 hours. Finally, 72.5g of perfluoroheptanoic acid was obtained by distillation, with a yield of 69% and a purity of 98%.
[0079] Comparative Example 1
[0080] In a 500ml reactor, 150g of dodecafluoroheptanol, 63g of 65% concentrated nitric acid, and 0.3g of ferric chloride were added. The mixture was stirred and heated to 125°C at a pressure of 0.23MPa, and the reaction was continued for 5 hours. After cooling, the lower layer was separated and distilled to obtain 122g of dodecafluoroheptanoic acid, with a yield of 88%. The obtained dodecafluoroheptanoic acid was added to another 500ml reactor, along with 95g of tetrahydrofuran. 52g of thionyl chloride was added dropwise under stirring. After the addition was complete, the temperature was raised to 60°C and the reaction was maintained for 2.5 hours. Distillation yielded 120g of dodecafluoroheptanoyl chloride, with a yield of 93%. The obtained product was added to a 250ml fluorination reactor, stirred, and heated to 60°C. 25% fluorine gas was introduced from the bottom of the material at a rate of 250ml / min. The gas was continuously introduced for 20 hours, and samples were taken for testing. The reaction was complete. 103 grams of the material were collected, with a yield of 95%. The fluorinated product was heated to 50°C, and 8 grams of deionized water were added. The mixture was stirred continuously for 3 hours. Negative pressure distillation yielded 92 grams of perfluoroheptanoic acid with a purity of 95.8%. The overall yield was 74.5%.
[0081] Comparative Example 2
[0082] 156 g of perfluorohexylethylene and 30 g of concentrated sulfuric acid were added to a 500 ml four-necked flask equipped with a mechanical stirrer, condenser, and thermometer, and nitrogen gas was introduced. 60 g of potassium permanganate was added in five portions, with 15-minute intervals between each addition, while maintaining the temperature at 40-60 °C. After the additions were complete, the mixture was stirred for 3 hours to obtain a black suspension. The black suspension was filtered at 50 °C to obtain 132 g of a colorless, transparent solution, which was perfluoroheptanoic acid. This perfluoroheptanoic acid is a white crystalline solid at room temperature. GC testing of the above perfluoroheptanoic acid revealed a purity of 99% and a yield of 82.5%.
[0083] Comparative Example 3
[0084] 180 g of perfluorobutylethylene and 40 g of concentrated sulfuric acid were added to a 500 ml four-necked flask equipped with a mechanical stirrer, condenser, and thermometer, and nitrogen gas was introduced. 80 g of potassium permanganate was added in eight portions, with 15-minute intervals between each addition, while maintaining the temperature at 60-80 °C. After the additions were complete, the mixture was stirred for 6 hours to obtain a black suspension. The black suspension was filtered at 60 °C. 160 g of a colorless, transparent solution was obtained, which was perfluoropentanoic acid. This perfluoropentanoic acid is a white crystalline solid at room temperature. GC testing of the perfluoropentanoic acid revealed a purity of 98% and a yield of 85%.
[0085] A comparison of Examples 1-10 and Comparative Examples 1-3 shows that the preparation process of Comparative Example 1 is significantly more complicated, but the yield of perfluorocarboxylic acid obtained by Comparative Example 1 is not superior to that of the examples in this application. In Comparative Examples 2 and 3, the use of potassium permanganate and concentrated sulfuric acid results in a highly exothermic reaction, requiring sophisticated reaction equipment, posing low safety risks, and generating large amounts of solid waste, making industrial production impossible. In summary, the preparation method of this embodiment uses a green and environmentally friendly oxidant, requires low energy consumption, does not generate large amounts of solid waste, is environmentally friendly and safe, suitable for industrial production, and uses inexpensive and readily available raw materials.
[0086] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.
[0087] The products and preparation methods provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A process for the preparation of a perfluorocarboxylic acid, characterized in that, Includes the following steps: A solvent, a first compound containing a transition metal element, and a second compound containing a peroxy group are added to a perfluorinated α-olefin monomer, respectively. After mixing, reaction, and distillation, perfluorocarboxylic acid is obtained. The transition metal element is selected from at least one of the transition metal elements of group IVB, group VB or group VIB.
2. The method of claim 1, wherein the perfluorocarboxylic acid is prepared by the reaction of a perfluoroalkyl iodide with a carboxylic acid in the presence of a base. The mass ratio of the perfluorinated α-olefin monomer, solvent, first compound, and second compound is 100:(40-60):(0.1-0.2):(75-230).
3. The method of claim 1, wherein the perfluorocarboxylic acid is prepared by the reaction of a perfluoroalkyl iodide with a carboxylic acid in the presence of a base. 5 In the perfluorinated α-olefin monomer, the α-olefin is selected from at least one of 1-pentene, 1-hexene, 1-heptene, and 1-octene.
4. The method of claim 1, wherein the perfluorocarboxylic acid is prepared by the reaction of a perfluoroalkyl iodide with a carboxylic acid in the presence of a base. The perfluorinated α-olefin monomer is selected from at least one of perfluorohexylethylene, perfluorobutylethylene, and perfluoropentylethylene; and / or The perfluorocarboxylic acid is selected from at least one of perfluorovaleric acid, perfluorohexanoic acid, and perfluoroheptanoic acid.
5. The method of claim 1, wherein the perfluorocarboxylic acid is prepared by the reaction of a perfluoroalkyl iodide with a carboxylic acid in the presence of a base. The transition metal element is selected from at least one of vanadium, titanium, and molybdenum.
6. The method of claim 5, wherein the perfluorocarboxylic acid is prepared by the reaction of a perfluoroalkyl iodide with a carboxylic acid in the presence of a base. The first compound is selected from at least one of acetylacetonate vanadium oxyacetate, vanadium oxyacetate, vanadium oxysulfate, vanadium oxyoxalate, vanadium oxybenzoate, bis(pyridine-2-carboxylic acid) vanadium oxyacetate, bis(maltol) vanadium oxyacetate titanium oxyacetate, isopropyl titanium oxyacetate, titanium oxysulfate, titanium oxyphthalocyanine, titanium oxyoxalate ammonium, bis(2,2,6,6-tetramethyl-3,5-heptanoic acid) titanium oxide, [1,2-phenylene glycol (2-)-O,O'] titanium oxyacetate molybdenum oxyacetate.
7. The method of claim 1, wherein the perfluorocarboxylic acid is prepared by the reaction of a perfluoroalkyl iodide with a carboxylic acid in the presence of a base. The second compound is selected from at least one of the following peroxides: hydrogen peroxide, sodium peroxide, urea peroxide, peracetic acid, dicumyl peroxide, benzoyl peroxide, tert-butyl hydrogen peroxide, di-tert-butyl peroxide, and m-chloroperoxybenzoic acid.
8. The method for preparing a perfluorocarboxylic acid according to claim 1, characterized in that, The reaction temperature is 10–40℃, and the reaction time is 6–12 h.
9. The method for preparing a perfluorocarboxylic acid according to claim 1, characterized in that, The solvent has a pH of 1 to 3; and / or The solvent is selected from at least one of trifluoroacetic acid, trifluoropropionic acid, and trifluorobutyric acid.
10. A perfluorocarboxylic acid, characterized in that, The perfluorocarboxylic acid is prepared by the preparation method according to any one of claims 1-9.