Catalyst for synthesis of fluorosurfactant and its preparation method and application

Abstract

The application discloses a catalyst for fluorine-containing surfactant synthesis and a preparation method and application thereof, and relates to the field of fluorine-containing surfactants. The preparation method of the catalyst comprises the following steps: S1. under the protection of an inert atmosphere, CoCl2 is mixed with PQ3 in a solvent to prepare raw material B; S2. under the protection of an inert atmosphere, raw material B is activated with raw material A in a solvent to obtain a catalyst for fluorine-containing surfactant synthesis; the solvent is an aprotic solvent; Q in the PQ3 is one of a Ph group and a Cy group. The application of the catalyst is the application of the catalyst in the catalytic synthesis of fluorine-containing surfactants. The preparation method of the catalyst provided in the application not only has high product yield, but also has high product purity; when the catalyst is applied to the preparation of fluorine-containing surfactants, the selectivity and conversion rate of the target product can be effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fluorine-containing surfactants, in particular to a catalyst for the synthesis of fluorine-containing surfactants and a preparation method and application thereof. BACKGROUND

[0002] One of the main characteristics of fluorine-containing chains is high thermal and chemical stability, but because of this, the corresponding compounds are persistent in the environment and difficult to degrade. The most widely used fluorine-containing surfactants mainly include perfluorooctyl sulfonic acid with different hydrophobic chain lengths, perfluorooctanoic acid with different hydrophobic chain lengths, and their derivatives, etc. Their structures can be hydroxyl, metal salt or other salt, halide, amino, and other derivative groups including polymers. PFOS / PFOA fluorine-containing surfactants are found to have bioaccumulation in the food chain, and have a long half-life in human blood, with PFOA up to 3.6 years, PFOS up to 5.4 years, and perfluorohexyl sulfonic acid up to 8.5 years. In addition, they also have the possibility of long-distance environmental migration, and therefore are limited in use. At present, the development of PFOS / PFOA substitutes has been carried out by countries all over the world.

[0003] A new type of fluorine-containing surfactant containing ether bonds used in the polymerization of polytetrafluoroethylene has the following structure:

[0004]

[0005] That is, a fluorine-containing surfactant of 8 carbon type, which also has good application effect in the polymerization of fluorine-containing polymers.

[0006] In the prior art, the catalyst used to synthesize the above-mentioned 8 carbon type fluorine-containing surfactant is mainly potassium fluoride and cesium fluoride, and the solvent used is a polar aprotic solvent. However, the catalytic activity of potassium fluoride is low, and the 8 carbon type new fluorine-containing surfactant cannot be obtained under the premise of high selectivity and yield. Although the catalytic activity of cesium fluoride is higher than that of potassium fluoride, it is expensive and has strong hygroscopicity, which causes difficulties in industrialization. SUMMARY

[0007] In order to improve the selectivity and reaction conversion rate of the 8 carbon type new fluorine-containing surfactant, the present application provides a catalyst for the synthesis of fluorine-containing surfactants and a preparation method and application thereof.

[0008] The catalyst for the synthesis of fluorine-containing surfactants provided by the present application adopts the following technical scheme:

[0009] The catalyst for the synthesis of fluorine-containing surfactants has the following structure:

[0010]

[0011] In formula (I), R is one of PPh3 group, PCy3 group.

[0012] By adopting the technical scheme, the metal cobalt complex obtained by compounding is applied to the synthesis reaction of fluorine-containing surfactant as a catalyst, and compared with the traditional inorganic catalyst, the selectivity of the new fluorine-containing surfactant can be obviously improved under the same amount, and the reaction conversion rate is improved, the amount of solvent is reduced, and the production cost of the new fluorine-containing surfactant is further reduced.

[0013] The preparation method of the catalyst for the synthesis of fluorine-containing surfactant provided by the application adopts the following technical scheme: a preparation method of a catalyst for the synthesis of fluorine-containing surfactant, characterized by comprising the following steps:

[0014] S1. Under the protection of an inert atmosphere, CoCl2 and PQ3 are mixed and reacted in a solvent to obtain raw material B;

[0015] S2. Under the protection of an inert atmosphere, raw material B and raw material A are activated and reacted in a solvent to obtain a catalyst for the synthesis of fluorine-containing surfactant;

[0016] The solvent is an aprotic solvent;

[0017] Q in the PQ3 is one of a Ph group and a Cy group;

[0018] The structural formula of the raw material B is one of Co(PPh3)4 and Co(PCy3)4;

[0019] The structural formula of the raw material A is as follows:

[0020]

[0021] By adopting the technical scheme, the metal cobalt complex is synthesized, the yield and conversion rate of the reaction are high, the purity of the product is high, the target product metal cobalt complex can be effectively obtained, and the metal cobalt complex is applied to the synthesis reaction of fluorine-containing surfactant, so that the selectivity and conversion rate of the product can be effectively improved.

[0022] Preferably, the preparation method of the raw material B comprises the following steps: CoCl2 and PQ3 are mixed in a solvent, and mixed and reacted at a temperature of 20-50℃ for 2-5h; after the reaction is completed, the reaction liquid is cooled to room temperature, the precipitate in the reaction liquid is extracted, and the extracted liquid is recrystallized to obtain the raw material B.

[0023] Preferably, the molar ratio of CoCl2 to PQ3 in S1 is 6-8:24-34.4, and the ratio of the total amount of substance of CoCl2 and PQ3 to the amount of solvent is (30-60) mmol:(40-90) mL.

[0024] Preferably, the molar ratio of raw material B to raw material A in S2 is 1-3:1.1-3.1, and the ratio of the total amount of substance of raw material B and raw material A to the amount of solvent is (5-10) mmol:(20-50) mL.

[0025] Preferably, the activation reaction temperature in S2 is 25-50℃, and the reaction time is 2-5h.

[0026] Preferably, after the activation reaction in S2 is completed, the obtained precipitate in the reaction is cooled to room temperature, then the precipitate is suction filtered, and the precipitate is washed with dichloromethane, and the washed solid is dried to obtain the catalyst.

[0027] The application provides the use of the catalyst for the synthesis of fluorine-containing surfactant, which uses the following technical scheme:

[0028] The use of the catalyst for the synthesis of fluorine-containing surfactant, characterized in that the use of the catalyst is the use of the catalyst in the reaction of catalytic synthesis of fluorine-containing surfactant.

[0029] Preferably, the preparation method of the fluorine-containing surfactant comprises the following steps:

[0030] The catalyst, tetraethylene glycol dimethyl ether, trifluoroacetyl fluoride and hexafluoropropylene oxide are mixed, and then stirred and reacted at-100-0℃ for 3-8h to obtain the fluorine-containing surfactant.

[0031] The structure of the fluorine-containing surfactant is as follows:

[0032]

[0033] Preferably, the mass ratio of the catalyst, tetraethylene glycol dimethyl ether, trifluoroacetyl fluoride and hexafluoropropylene oxide is 1:110-150:25-55:180-240, preferably 1:130:30:190.

[0034] In summary, the application has at least one of the following beneficial technical effects:

[0035] 1. By adopting the technical scheme, the obtained metal cobalt complex is applied to the synthesis reaction of the new fluorine-containing surfactant as a catalyst, in comparison with the traditional inorganic catalyst, the selectivity of the new fluorine-containing surfactant can be obviously improved under the same amount, in addition, the reaction conversion rate is improved, the amount of solvent is reduced, and the production cost of the new fluorine-containing surfactant is further reduced. DETAILED DESCRIPTION

[0036] The application will be further described in detail below in combination with examples.

[0037] Example

[0038] Example 1

[0039] The structural formula of the raw material A in the embodiment is:

[0040]

[0041] The structural formula of the raw material B is Co(PPh3)4;

[0042] The catalyst has the structure shown in formula (I-1):

[0043]

[0044] S1. Under a nitrogen protection system, raw material CoCl2 83.2 mmol (10.8 g) and PPh3 (triphenylphosphine) 356.6 mmol (93.5 g) were weighed and added to the reaction system, 660 mL of solvent THF was added, and the reaction was carried out at 40°C for 3h under nitrogen protection. After the reaction was completed, the solvent THF was extracted with methyl tert-butyl ether, and the extracted liquid was placed in a 0°C refrigerator, and yellow block crystals were obtained after recrystallization, which were raw material B;

[0045] S2. Raw material B 53.7 mmol (59.5 g) was weighed, raw material A 64.4 mmol (12.0 g) was added, and solvent THF 315 mL was added to the system, and the reaction was carried out at 35°C for 4h under nitrogen protection. After the reaction was completed, the solvent was extracted by filtration, and the remaining solid after washing was placed in a vacuum drying oven to obtain an orange powder cobalt metal complex, which was a catalyst for the synthesis of a fluorine-containing surfactant.

[0046] Example 2

[0047] The structures of the raw material A, the raw material B and the catalyst in the embodiment are the same as those in example 1;

[0048] The preparation method of the catalyst for the synthesis of the new fluorine-containing surfactant comprises the following steps:

[0049] S1. Under the nitrogen protection system, the raw material CoCl2 167.1mmol (21.7g) and PPh3 716.1mmol (187.8g) were weighed and added into the reaction system, 1325mL of solvent THF was added, and the reaction was carried out at 20℃ for 5h under the nitrogen protection. After the reaction was completed, the solvent THF was extracted, and the extraction liquid was placed in a 0℃ refrigerator, and yellow block crystals were obtained after recrystallization, which were the raw material B;

[0050] S2. The raw material B 173.2mmol (191.9g) was weighed, the raw material A 207.8mmol (38.7g) was added, and then the solvent THF 1020mL was added into the system, and the reaction was carried out at 25℃ for 5h under the nitrogen protection. After the reaction was completed, the solvent was extracted by filtration, and the remaining solid after washing was placed in a vacuum drying oven to obtain an orange powder of cobalt metal complex, which was the catalyst for the synthesis of fluorine-containing surfactant.

[0051] Example 3

[0052] The structures of the raw material A, the raw material B and the catalyst in this example are the same as those in Example 1;

[0053] The preparation method of the catalyst for the synthesis of the new fluorine-containing surfactant comprises the following steps:

[0054] S1. Under the nitrogen protection system, the raw material CoCl2 167.1mmol (21.7g) and PPh3 716.1mmol (187.8g) were weighed and added into the reaction system, 1325mL of solvent THF was added, and the reaction was carried out at 20℃ for 5h under the nitrogen protection. After the reaction was completed, the solvent THF was extracted, and the extraction liquid was placed in a 0℃ refrigerator, and yellow block crystals were obtained after recrystallization, which were the raw material B;

[0055] S2. The raw material B 173.2mmol (191.9g) was weighed, the raw material A 207.8mmol (38.7g) was added, and then the solvent THF 1020mL was added into the system, and the reaction was carried out at 25℃ for 5h under the nitrogen protection. After the reaction was completed, the solvent was extracted by filtration, and the remaining solid after washing was placed in a vacuum drying oven to obtain an orange powder of cobalt metal complex, which was the catalyst for the synthesis of fluorine-containing surfactant.

[0056] Example 4

[0057] The structural formula of the raw material A in this example is the same as that in Example 1;

[0058] The structural formula of the raw material B is Co(PCy3)4;

[0059] The catalyst has a structure shown in formula (I-2):

[0060]

[0061] S1. Under a nitrogen protection system, raw material CoCl274.1 mmol (9.6 g) and PCy3 (tricyclohexylphosphine) 317.6 mmol (89.1 g) were weighed and added into a reaction system, 590 mL of solvent THF was added, and the reaction was carried out at 40°C for 3 h under nitrogen protection. After the reaction was completed, the reaction system was cooled to room temperature, the solvent THF was removed by suction, and methyl tert-butyl ether was used for extraction. The extracted solution was placed in a 0°C refrigerator, and orange rod-shaped crystals were obtained by recrystallization, which were raw material B;

[0062] S2. Raw material B 67.8 mmol (80.1 g) and raw material A 81.4 mmol (15.1 g) were weighed and added into a reaction system, 400 mL of solvent THF was added, and the reaction was carried out at 35°C for 4 h under nitrogen protection. The solvent was removed by suction, and dichloromethane was used for washing. The remaining solid after washing was dried in a vacuum drying oven to obtain a brown cobalt metal complex, which was a catalyst for synthesizing a fluorine-containing surfactant.

[0063] Example 5

[0064] In this example, the structures of raw material A, raw material B and the catalyst were the same as those in Example 2.

[0065] S1. Under a nitrogen protection system, raw material CoCl2201.3 mmol (26.1 g) and PCy3 862.7 mmol (241.9 g) were weighed and added into a reaction system, 1600 mL of solvent THF was added, and the reaction was carried out at 20°C for 5 h under nitrogen protection. Then, the reaction system was cooled to room temperature, the solvent THF was removed by suction, and methyl tert-butyl ether was used for extraction. The extracted solution was placed in a 0°C refrigerator, and orange rod-shaped crystals were obtained by recrystallization, which were raw material B.

[0066] S2. Raw material B 151.9 mmol (179.3 g) and raw material A 182.3 mmol (33.9 g) were weighed and added into a reaction system, 900 mL of solvent THF was added, and the reaction was carried out at 25°C for 5 h under nitrogen protection. The solvent was removed by suction, and n-pentane was used for washing. The remaining solid after washing was dried in a vacuum drying oven to obtain a brown cobalt metal complex, which was a catalyst for synthesizing a fluorine-containing surfactant.

[0067] Example 6

[0068] In this example, the structures of raw material A, raw material B and the catalyst were the same as those in Example 1.

[0069] S1. Under a nitrogen protection system, raw material CoCl2 274.1 mmol (35.6 g) and PCy3 1174.7 mmol (329.4 g) were weighed and added to the reaction system, 2180 mL of solvent THF was added, and the reaction was carried out at 50°C for 2 h under nitrogen protection. After the reaction was completed, the solvent THF was extracted with methyl tert-butyl ether, and the extract was placed in a 0°C refrigerator and recrystallized to obtain orange rod-shaped crystals, which were the raw material B;

[0070] S2. The raw material B 213.1 mmol (251.6 g) was weighed, the raw material A 255.7 mmol (47.6 g) was added, and the solvent THF 1250 mL was added to the system, and the reaction was carried out at 50°C for 2 h under nitrogen protection. The solvent was extracted and washed with dichloromethane, and the remaining solid after washing was dried in a vacuum drying oven to obtain a brown cobalt metal complex, which was a catalyst for the synthesis of fluorine-containing surfactants.

[0071] Application Example

[0072] Application Example 1

[0073] Under the condition of high-purity nitrogen protection, 52.6 g of the catalyst obtained from Example 1, 10 kg of hexafluoropropylene oxide, 1.58 kg of trifluoroacetyl fluoride, and 6.84 kg of solvent tetraethylene glycol dimethyl ether were added to a 30 L mechanically stirred kettle, and the reaction was carried out at a reaction temperature of -5°C for 6 h to obtain a fluorine-containing surfactant.

[0074] Application Example 2

[0075] Under the condition of high-purity nitrogen protection, 52.6 g of the catalyst obtained from Example 1, 9.47 kg of hexafluoropropylene oxide, 1.32 kg of trifluoroacetyl fluoride, and 5.79 kg of solvent tetraethylene glycol dimethyl ether were added to a 30 L mechanically stirred kettle, and the reaction was carried out at a reaction temperature of -100°C for 3 h to obtain a fluorine-containing surfactant.

[0076] Application Example 3

[0077] Under the condition of high-purity nitrogen protection, 52.6 g of the catalyst obtained from Example 1, 12.62 kg of hexafluoropropylene oxide, 2.89 kg of trifluoroacetyl fluoride, and 7.89 kg of solvent tetraethylene glycol dimethyl ether were added to a 30 L mechanically stirred kettle, and the reaction was carried out at a reaction temperature of -0°C for 8 h to obtain a fluorine-containing surfactant.

[0078] Application Example 4

[0079] The difference between Application Example 4 and Application Example 1 is that the catalyst used in Application Example 4 is from Example 4, and the mass is 52.6 g.

[0080] Application Example 5

[0081] Application Example 5 differs from Application Example 1 in that the catalyst used in Application Example 5 is from Example 1, and the mass is 26.3 g.

[0082] Comparative Application Example 1

[0083] Comparative Application Example 1 differs from Application Example 1 in that the catalyst used in Comparative Application Example 1 is CsF, and the mass is 52.6 g.

[0084] Comparative Application Example 2

[0085] Comparative Application Example 2 differs from Application Example 1 in that the catalyst used in Comparative Application Example 2 is KF, and the mass is 52.6 g.

[0086] Performance detection test

[0087] 1. The mass of the catalyst obtained from Examples 1-6 was weighed to calculate the yield; and the purity of the catalyst was detected, mass spectrometric analysis and elemental analysis were performed, and the results are shown in Table 1.

[0088] 2. The selectivity and reaction conversion rate of the fluorine-containing surfactant obtained from Application Examples 1-5 and Comparative Application Examples 1-2 were calculated, and the results are shown in Table 2.

[0089] The specific detection results are as follows:

[0090] Table 1 Performance detection results of Examples 1-6

[0091]

[0092]

[0093] From the detection results in Table 1, it can be seen that the preparation method of the catalyst for synthesizing the fluorine-containing surfactant provided in the present application not only has a higher yield of the catalyst product, but also has a higher purity of the catalyst product. The results of mass spectrometric analysis and elemental analysis show that the calculated value of the product is relatively close to the test value, indicating that the reaction method provided in the present application can effectively obtain the target product.

[0094] Table 2 Performance detection results of Application Examples 1-5 and Comparative Application Examples 1-2

[0095] Selectivity of product / % Reaction conversion / % Application Example 1 91.1 96.4 Application Example 2 90.5 95.7 Application Example 3 90.2 95.4 Application Example 4 86.9 88.9 Application Example 5 90.8 96.7 Comparative Application Example 1 51.3 69.7 Comparative Application Example 2 39.4 53.1

[0096] As can be seen from the detection results of Table 2, in the polymerization reaction, when the metal organic complex provided by the application is used as a catalyst, the selectivity and yield of the synthesis reaction can be obviously improved under the premise of reducing the amount of catalyst; in particular, in application example 1, the selectivity and yield of the new fluorine-containing surfactant are the highest, and it is easy to separate and remove; in comparison, in application examples 1-2, CsF and KF are used as catalysts respectively, but the selectivity and yield of the reaction are obviously lower, which shows that the solubility of the catalyst in the solvent has a great influence on the reaction conversion rate. When the solubility of the catalyst is higher, it is easier to ionize into the solvent to form an active ion loose pair to react with trifluoroacetyl fluoride and hexafluoropropylene oxide. In addition, for the organic metal complex, the substituent group coordinated with the metal also has a great influence on the catalytic activity of the catalyst; when the substituent group is an aromatic ring, a superconjugate effect is formed, at this time, the fluorine atom activated by the metal cobalt is more likely to be removed, so that the concentration of fluorine ions in the reaction solvent is increased, which promotes the ring-opening of hexafluoropropylene oxide, so that the hexafluoropropylene oxide after ring-opening is more likely to react with trifluoroacetyl fluoride, thereby effectively improving the selectivity of the new fluorine-containing surfactant and the conversion rate of the reaction.

[0097] The specific embodiments are only an explanation of the application, and are not a limitation of the application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, as long as the modifications are within the scope of the claims of the application, and are protected by the patent law.

Claims

1. A catalyst for the synthesis of fluorinated surfactants, characterized in that: The structural formula of the catalyst is: In formula (I), R is one of a PPh3 group and a PCy3 group.

2. The use of the catalyst for the synthesis of fluorinated surfactants according to claim 1, characterized in that: The application of the catalyst is the application of the catalyst in the catalytic synthesis reaction of fluorine-containing surfactants.

3. The use of the catalyst for the synthesis of fluorinated surfactants according to claim 2, characterized in that: The preparation method of the fluorinated surfactant comprises the following steps: After mixing the catalyst, tetraethylene glycol dimethyl ether, trifluoroacetyl fluoride and hexafluoropropylene oxide, stirring and reacting at -100 to 0°C for 3 to 8 hours, a fluorine-containing surfactant is obtained; The structural formula of the fluorinated surfactant is as follows:

4. The use of the catalyst for the synthesis of fluorinated surfactants according to claim 3, characterized in that: The mass ratio of the catalyst, tetraethylene glycol dimethyl ether, trifluoroacetyl fluoride and hexafluoropropylene oxide is 1:110-150:25-55:180-240.

5. The use of the catalyst for the synthesis of fluorinated surfactants according to claim 4, characterized in that: The mass ratio of the catalyst, tetraethylene glycol dimethyl ether, trifluoroacetyl fluoride and hexafluoropropylene oxide is 1:130:30:190.

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