CN102633688A - Perfluorovinyl ether sulfonate as well as preparation method and application thereof - Google Patents

Abstract

The invention relates to a perfluorovinyl ether sulfonate and its preparation method and application. The perfluorovinyl ether sulfonate is a compound represented by formula I, which is prepared by reacting the corresponding sulfonyl fluoride with an aqueous inorganic alkali solution. The perfluorovinyl ether sulfonate provided by the invention is a reactive surfactant and is environmentally friendly.

In formula I, M is Na ⁺ , K ⁺ or NH ₄ ⁺ , X is an integer of 0-2, and Y is an integer of 2-6.

Description

Perfluorovinyl ether sulfonate and its preparation method and use

technical field

The invention relates to a perfluorovinyl ether sulfonate and its preparation method and application.

Background technique

Fluorinated surfactants have the characteristics of high surface activity, high thermal stability and high chemical stability, and are both water-repellent and oil-repellent. They are widely used in many fields such as chemistry, chemical industry, textile, leather, construction, petroleum, fire protection, etc. In the production of fluorine-containing resins, rubber, coatings, fabric finishing agents, etc., it is necessary to use fluorine-containing surfactants as emulsifiers for emulsion polymerization, and the most widely used fluorine-containing surfactants are perfluorosulfonates (PFOS ) and perfluorooctanoate (PFOA).

Studies have shown that PFOS and PFOA are difficult to degrade in the natural environment, have the basic characteristics of persistent environmental organic pollutants, accumulate in the environment and accumulate in human and animal tissues, and pose potential dangers to human health and the environment. Therefore, PFOS and PFOA are currently The use of PFOA has been banned or restricted by the European Union, the United States and many countries and regions, and it is imminent to develop new fluorine-containing surfactants that meet environmental protection requirements.

In recent years, reactive surfactants, especially polymerizable emulsifiers, have attracted more and more interest. They are a type of emulsifiers that contain polymerizable reactive groups in their molecular structures, and can be copolymerized with polymerizable monomers during emulsion polymerization. , so as to permanently bond to the polymer surface and become a part of the polymer, which can solve many deficiencies of traditional surfactants.

During the emulsion polymerization of fluorine-containing monomers, polymerizable fluorine-containing surfactants are used as emulsifiers, which can be copolymerized with fluorine-containing monomers, so that they are bonded to the surface of the resulting fluorine-containing polymers and will not enter the natural environment neutralization or in the human body, avoiding threats to the environment and human health.

Therefore, developing a kind of environment-friendly polymerizable fluorine-containing surfactant is a problem to be solved in the present invention.

Contents of the invention

Perfluorovinyl ether sulfonyl fluoride or perfluorovinyl ether sulfonate is an important monomer for the preparation of perfluorosulfonic acid resins, and its double bonds allow it to be copolymerized with various fluorine-containing and non-fluorine monomers .

The present invention discloses a perfluorovinyl ether sulfonate, which not only contains polymerizable functional groups (unsaturated bonds), but also contains hydrophilic and hydrophobic groups, and can be used as a reactive surfactant for fluorine-containing monomers emulsion polymerization.

One object of the present invention is to provide a novel perfluorovinyl ether sulfonate. The perfluorovinyl ether sulfonate of the present invention has the structure shown in formula I:

In formula I, M is Na ⁺ , K ⁺ or NH ₄ ⁺ , X is an integer of 0-2, and Y is an integer of 2-6.

Another object of the present invention is to provide a method for preparing the compound shown in the above formula I, the main steps of the method are: the compound shown in the formula II and the corresponding inorganic base (such as NaOH, KOH or NH ₃ ·H ₂ O) prepared by aqueous solution reaction.

Another purpose of the present invention is to disclose an application of the compound represented by formula I, that is, as a reactive surfactant (specifically, for emulsion polymerization of fluorine-containing monomers, etc.).

Description of drawings

Concentration and surface tension curve of the perfluorovinyl ether sulfonate prepared by Fig. 1 in Example 1

Concentration and surface tension curve of the perfluorovinyl ether sulfonate prepared by Fig. 2 in Example 2

Fig. 3 is compared by the particle diameter of the emulsion prepared by embodiment 10 and comparative example 2

Fig. 4 is compared by the particle diameter of the emulsion prepared by embodiment 13 and comparative example 3

Detailed ways

The more specific steps of the method for preparing the compound shown in formula I provided by the present invention are: adding perfluorovinyl ether sulfonyl fluoride (shown in formula II) at room temperature (5°C to 35°C) and stirring Compound) is added dropwise an aqueous alkali solution until the pH value of the reaction solution is 7 to 10 (preferably 8 to 9), then stop the dripping of the aqueous alkali solution, filter, and the filter cake is washed and recrystallized successively (the solvent for recrystallization is preferably acetone ) and drying, to obtain the target (compound shown in formula I);

Wherein, the aqueous alkali solution is an aqueous solution of sodium hydroxide or potassium hydroxide, or ammonia water, and its concentration is preferably 1wt%-52wt%, more preferably 10wt%-30wt%.

The application of the perfluorovinyl ether sulfonate (compound shown in formula I) provided by the present invention as a reactive surfactant, specifically as: the compound shown in formula I can be used as an emulsifier for polymerizable monomers (including Emulsion polymerization of fluorine or fluorine-free polymerizable monomers). Since the compound represented by formula I is a reactive surfactant, it will undergo free radical copolymerization with the polymerizable monomer, thereby "bonding" to the polymer, thereby avoiding environmental pollution.

The specific method of use is to disperse the compound shown in formula I and/or other additives (such as stabilizer paraffin, etc.) in water, add the polymerizable monomer to emulsify under stirring, then add the initiator, under certain conditions Polymerize for several hours to obtain a polymer (material) emulsion,

Wherein, the amount of the compound shown in formula I is 0.1wt%～10wt% (more preferably 1wt%～3wt%) of the total weight of the polymerizable monomer, and the described polymerizable monomer is selected from: tetrafluoroethylene, vinylidene fluoride , hexafluoropropylene, trifluorochloroethylene, trifluorostyrene, perfluoroalkyl vinyl ether, fluorinated acrylate and other perfluorinated monomers or partially fluorinated monomers; or ethylene, propylene, vinyl chloride, styrene , vinyl acetate, acrylates, and other hydrocarbon monomers containing polymerizable functional groups, or a mixture of two or more (including two).

In addition, the perfluorovinyl ether sulfonate (compound represented by formula I) provided by the present invention can be used alone as an emulsifier, or used after compounding with other existing emulsifiers (fluorine-containing or non-fluorine-containing emulsifiers) , when the perfluorovinyl ether sulfonate (compound represented by formula I) provided by the present invention is used as an emulsifier, its suitable use temperature is 30°C to 130°C.

The present invention mainly has the following advantages:

1. The perfluoroalkyl vinyl ether sulfonate involved in the present invention has a good effect of reducing the surface tension of water, and its maximum ability to reduce the surface tension of aqueous solution can reach about 20mN/m;

2. The perfluoroalkyl vinyl ether sulfonate involved in the present invention contains polymerizable double bonds. When used as an emulsifier, it can undergo free radical copolymerization with monomers, thereby "bonding" in the polymer, completely The environmental pollution of the small molecule fluorine-containing emulsifier is avoided.

3. When the perfluoroalkyl vinyl ether sulfonate involved in the present invention is used as an emulsifier, it has a wide applicable temperature range and a wide range of applicable monomers, and has a good application prospect.

The present invention will be further elaborated below by embodiment. It should be understood that the following examples are only used to better understand the content of the present invention, and cannot be interpreted as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by professionals in this field according to the content of the present invention still belong to the present invention scope of protection.

Example 1

The preparation of compound shown in formula Ia

Add 22.3g of perfluoro-4-methyl-6-vinyl-3,6-dioxobutylsulfonyl fluoride to a 250mL round bottom flask, stir at room temperature, and gradually add 10% hydrogen to the system Sodium oxide aqueous solution is about 44mL, until the pH of the system reaches 8-9, stop the reaction, filter the mixture, transfer the resulting white solid to a beaker, add 100mL of acetone to dissolve, filter out the white solid that is insoluble in acetone, and rotary evaporate the acetone , and dried to obtain 21.2 g of a white solid product (the title compound), with a yield of 90.9%.

¹⁹ F NMR (D ₂ O, 400 MHz): δppm -81, -82, -87, -116.5, -119.5, -138.5, -147. See Figure 1 for the surface tension data of the title compound.

Example 2

The preparation of compound shown in formula Ib

Add 22.3g of perfluoro-4-methyl-6-vinyl-3,6-dioxobutylsulfonyl fluoride to a 250mL round bottom flask, stir at room temperature, and gradually add 10% hydrogen to the system Potassium oxide aqueous solution until the pH of the system reaches 8-9, stop the reaction, put the mixture in a round bottom flask, remove about half of the original solvent by rotary evaporation, then filter, wash the obtained solid with acetone, collect the acetone solution, and remove the solvent After evaporation and drying, 22.5 g of a white solid product (the title compound) was obtained, with a yield of 93.4%. The surface tension data is shown in Figure 2. NMR data (fluorine spectrum) are the same as described in Example 1.

Example 3

The preparation of compound shown in formula Ic

Add 22.3g of perfluoro-4-methyl-6-vinyl-3,6-dioxobutylsulfonyl fluoride to a 250mL round-bottomed flask in advance, stir at room temperature, and gradually add 10% ammonia water to the system dropwise When the pH of the system reaches 8-9, the reaction is stopped, the mixture is placed in a round-bottomed flask, and all solvents are removed by rotary evaporation. The gained solid is washed with acetone, the acetone solution is collected, the solvent is evaporated, and dried to obtain 20.615 g of a white solid product ( The title compound), the yield was 89.44%. NMR data (fluorine spectrum) are the same as described in Example 1.

Example 4

The preparation of compound shown in formula Id

Add 14.0 g of perfluoro 2-vinyloxyethylsulfonyl fluoride to a 250 mL round bottom flask in advance, stir at room temperature, gradually add 20% potassium hydroxide aqueous solution to the system until the pH of the system reaches 8-9, Stop the reaction, place the mixture in a round-bottomed flask, remove half of the original solvent by rotary evaporation, then filter, dissolve the solid with acetone, filter off the insolubles, evaporate the solvent, and dry to obtain 14.9 g of a solid product (title compound) , yield 94.3%.

¹⁹ F NMR (D ₂ O, 400 MHz): δppm -138.7, -123.76, -116.38, -114.23, -86.06.

Example 5

The preparation of compound shown in formula I e

Add 19.0 g of perfluoro 4-vinyloxybutylsulfonyl fluoride to a 250 mL round bottom flask in advance, stir at room temperature, gradually add 10% aqueous sodium hydroxide solution dropwise to the system until the pH of the system reaches 8-9, Stop the reaction, filter the mixture, transfer the resulting white solid to a beaker, add 100 mL of acetone to dissolve it, filter off the white solid that is insoluble in acetone, remove the acetone by rotary evaporation, and dry to obtain 18.4 g of solid product (the title compound). Yield 92.0 %.

Example 6

Polymerization of vinylidene fluoride

In a 10L horizontal reactor, add 6L deionized water and 12g perfluoro-4-methyl-6-vinyl-3,6-sodium dioxobutyl sulfonate (compound shown in formula Ia). After the reactor is closed, replace the air in the reactor with nitrogen. After the oxygen content is less than 50ppm, raise the temperature of the reactor to 130°C, then pump vinylidene fluoride monomer until the pressure of the reactor is 5MPa, and add 420g of vinylidene fluoride monomer in total. . Add 1.5g of 2,5-dimethyl-2,5-di-tert-butylperoxy-3-hexyne initiator after the pressure of the reactor is stable, and start to add vinylidene fluoride monomer to Maintain the reaction pressure at 5MPa, stop adding vinylidene fluoride monomer after the amount of added monomer reaches 1000g, and dry the taken out emulsion directly to obtain 1150g polyvinylidene fluoride polymer.

Example 7

Polymerization of vinylidene fluoride

In a 10L horizontal reactor, add 5L deionized water and 6g perfluoro-4-methyl-6-vinyl-3,6-sodium dioxobutyl sulfonate (compound shown in formula Ia). After the reactor is closed, the air in the reactor is replaced with nitrogen. After the oxygen content is less than 50ppm, the temperature of the reactor is raised to 70°C, and then the vinylidene fluoride monomer is pumped in until the pressure of the reactor is 4.5MPa, and a total of 530g of vinylidene fluoride monomer body. After the pressure of the reactor is stable, add 1.2g of sodium persulfate initiator. After the pressure drops, start to add vinylidene fluoride monomer to maintain the reaction pressure at 4.5MPa. After the amount of added monomer reaches 800g, stop adding vinylidene fluoride 950 g of polyvinylidene fluoride polymer can be obtained after directly drying the taken-out emulsion.

Example 8

Copolymerization

First, vinylidene fluoride and perfluoro-n-propyl vinyl ether (PPVE) are made into a mixed monomer according to the content of perfluoro-n-propyl vinyl ether in a ratio of 5mol%. 45°C.

In a 10L horizontal reactor, add 5L deionized water and 15g perfluoro-4-methyl-6-vinyl-3,6-sodium dioxobutyl sulfonate (compound shown in formula Ia). After the reactor is closed, the air in the reactor is replaced with nitrogen. After the oxygen content is less than 50ppm, the temperature of the reactor is raised to 65°C, and then the mixed monomer is pumped in until the pressure of the reactor is 3.8MPa, and a total of 490g of the mixed monomer is added. After the pressure of the reactor is stable, add 1.5g of potassium persulfate initiator. After the pressure drops, start to add mixed monomers to maintain the reaction pressure at 3.8MPa. After the amount of added monomers reaches 800g, stop adding vinylidene fluoride monomers 980g of polyvinylidene fluoride polymer can be obtained after the taken out emulsion is dried directly.

Example 9

Copolymerization

Firstly, vinylidene fluoride and hexafluoropropylene are formulated into a mixed monomer according to the ratio of hexafluoropropylene (HFP) content of 3 mol%, and placed in a monomer tank for later use, and the temperature of the mixed monomer is controlled at 30°C.

In a 10L horizontal reactor, add 6L deionized water and 6g perfluoro-4-methyl-6-vinyl-3,6-sodium dioxobutyl sulfonate (compound shown in formula Ia). After the reactor is closed, the air in the reactor is replaced with nitrogen. After the oxygen content is less than 50ppm, the temperature of the reactor is raised to 82°C, and then the mixed monomer is pumped in until the pressure of the reactor is 5.2MPa, and a total of 600g of the mixed monomer is added. Add 2g of sodium persulfate initiator after the pressure of the reactor is stabilized. After the pressure drops, start to add mixed monomers to maintain the reaction pressure at 5.2MPa. After the amount of added monomers reaches 1000g, stop adding vinylidene fluoride monomers. 1250 g of polyvinylidene fluoride polymer can be obtained after the taken out emulsion is dried directly.

Comparative example 1

The main raw materials and steps are the same as in Example 6, but ammonium perfluorooctanoate is used as the emulsifier, and a total of 15 g is added. The reaction temperature was 135° C., 400 g of monomers were added in the early stage of the reaction, and 1100 g of polymers were obtained after the reaction.

The experimental result of embodiment 6～9 and comparative example 1 is shown in table 1

Table 1

It can be seen from Table 1 that when the perfluorovinyl ether sulfonate provided by the present invention is used as an emulsifier, its emulsifying effect is comparable to or even better than that of ammonium perfluorooctanoate (the existing emulsifier).

Example 10

30 g of dodecafluoroheptyl methacrylate and 30 g of methyl methacrylate were dissolved in 110 g of water with 1.5 g of sodium perfluoro-4-methyl-6-vinyl-3,6-dioxobutylsulfonate (compound shown in formula I a) after emulsification, drip the initiator (potassium persulfate and sodium bisulfite) that dissolves with 30 grams of water under nitrogen protection, stop reaction after reacting 4 hours at 60 ℃, obtain solid content It is a 30% fluorinated acrylate emulsion. The obtained emulsion has a gel content of less than 0.5%, good stability, and can be stored at room temperature for more than 6 months without precipitation. The average particle diameter of the emulsion is about 110 nm and the distribution is concentrated.

Comparative example 2

An emulsion prepared with ammonium perfluorooctanoate as an emulsifier was used as a comparative example. The preparation of the comparative example is the same as that of Example 10, except that sodium perfluoro-4-methyl-6-vinyl-3,6-dioxobutylsulfonate is replaced by ammonium perfluorooctanoate. The emulsion particle diameters of Example 10 and Comparative Example 2 are shown in Figure 3. It can be seen from Figure 3 that the emulsifying effect of sodium perfluoro-4-methyl-6-vinyl-3,6-dioxobutyl sulfonate is comparable to that of ammonium perfluorooctanoate, or even slightly better.

Example 11

30 grams of dodecafluoroheptyl methacrylate and 30 grams of methyl methacrylate in 110 grams of water with 1.5 grams of emulsifier (perfluoro-4-methyl-6-vinyl-3,6-dioxobutyl Sodium sulfonate (compound shown in formula Ia) and each 0.75g of sodium lauryl sulfate) after emulsification, drip the initiator (potassium persulfate and sodium bisulfite) with 30 grams of water dissolving under nitrogen protection, After reacting at 60° C. for 4 hours, the reaction was stopped to obtain a fluorine-containing acrylate emulsion with a solid content of 30%. The gel content of the obtained emulsion is less than 0.5%, and the stability is good. It can be stored at room temperature for more than 6 months without precipitation. The average particle size of the emulsion is about 96nm and the distribution is concentrated.

Example 12

20 grams of perfluoroalkylethyl acrylate, 20 grams of methyl methacrylate and 20 grams of butyl methacrylate in 110 grams of water with 1.5 grams of emulsifier (perfluoro-4-methyl-6-vinyl- 3,6-dioxobutyl sulfonate potassium (compound shown in formula 1 b) and each 0.75g of sodium lauryl sulfate) emulsification, drip the potassium persulfate initiator that is dissolved in 10 grams of water under nitrogen protection, Polymerized at 70° C. for 4 hours to obtain a fluorine-containing acrylate emulsion with a solid content of 33%. The obtained emulsion has a gel content of less than 0.5%, good stability, and can be stored at room temperature for more than 6 months without precipitation. The average particle size of the emulsion is about 90 nm and the distribution is concentrated.

Example 13

Use hydroxyethyl methacrylate-terminated polyurethane as a macromonomer to carry out emulsion copolymerization with fluorine-containing acrylate and methacrylate. The specific method is as follows: Add polyurethane aqueous dispersion (containing 30 grams of polyurethane macromers) in the four-necked flask, add 0.2 grams of perfluoro-4-methyl-6-vinyl-3,6-dioxobutyl under nitrogen protection and stirring Sodium sulfonate (compound shown in formula I a) and the aqueous solution of 0.2 gram sodium lauryl sulfate, be heated to 65 ℃, dropwise comonomer (10 gram dodecafluoroheptyl methacrylate and 10 The mixed solution of gram methyl methacrylate) and initiator, obtain fluorine-containing polyurethane-acrylic ester emulsion after polymerization 4 hours.

Comparative example 3

An emulsion prepared with ammonium perfluorooctanoate as an emulsifier was used as a comparative example. The preparation of the comparative example is the same as that of Example 13, except that sodium perfluoro-4-methyl-6-vinyl-3,6-dioxobutylsulfonate is replaced by ammonium perfluorooctanoate. The emulsion particle diameters of Example 13 and Comparative Example 3 are shown in Figure 4.

It can be seen from Figure 4 that the emulsifying effect of perfluoroalkyl vinyl ether sulfonate is equivalent to that of ammonium perfluorooctanoate, or even slightly better.

Example 15

After emulsifying 30 grams of dodecafluoroheptyl methacrylate and 30 grams of methyl methacrylate in 110 grams of water with 1.5 grams of perfluoro-2-vinyl oxygen ethylsulfonate potassium (compound shown in formula 1 d), Under the protection of nitrogen, the initiator (potassium persulfate and sodium bisulfite) dissolved in 30 g of water was added dropwise, and the reaction was stopped after reacting at 60° C. for 4 hours to obtain a fluorine-containing acrylate emulsion with a solid content of 30%. The obtained emulsion has a gel content of less than 0.5%, good stability, and can be stored at room temperature for more than 6 months without precipitation. The average particle size of the emulsion is about 102nm and the distribution is concentrated.

Example 16

Polymerization of vinylidene fluoride

In a 10L horizontal reactor, add 6L deionized water and 12g potassium perfluoro-2-vinyloxyethanesulfonate (compound shown in formula Id). After the reactor is closed, replace the air in the reactor with nitrogen. After the oxygen content is less than 50ppm, raise the temperature of the reactor to 130°C, then pump vinylidene fluoride monomer until the pressure of the reactor is 5MPa, and add 420g of vinylidene fluoride monomer in total. . Add 1.5g of 2,5-dimethyl-2,5-di-tert-butylperoxy-3-hexyne initiator after the pressure of the reactor is stable, and start to add vinylidene fluoride monomer to Maintain the reaction pressure at 5 MPa, stop adding vinylidene fluoride monomer after the amount of added monomer reaches 1000g, and dry the taken out emulsion directly to obtain 1132g polyvinylidene fluoride polymer.

Example 17

20 grams of perfluoroalkylethyl acrylate, 20 grams of methyl methacrylate and 20 grams of butyl methacrylate in 110 grams of water with 1.5 grams of emulsifier (potassium perfluoro-4-vinyloxybutyl sulfonate (compound shown in formula I e) and each 0.75g of sodium lauryl sulfate) emulsification, drip the potassium persulfate initiator that is dissolved in 10 grams of waters under the protection of nitrogen, polymerize 4 hours at 70 ℃, obtain solid content It is a 33% fluorinated acrylate emulsion. The obtained emulsion has a gel content of less than 0.5%, good stability, and can be stored at room temperature for more than 6 months without precipitation. The average particle size of the emulsion is about 87nm and the distribution is concentrated.

Example 18

Copolymerization

First, vinylidene fluoride and perfluoro-n-propyl vinyl ether (PPVE) are made into a mixed monomer according to the content of perfluoro-n-propyl vinyl ether in a ratio of 5mol%. 45°C.

In a 10L horizontal reactor, add 5L ionized water and 15g perfluoro-4-vinyloxybutylene sulfonate sodium (compound shown in formula Ie). After the reactor is closed, the air in the reactor is replaced with nitrogen. After the oxygen content is less than 50ppm, the temperature of the reactor is raised to 65°C, and then the mixed monomer is pumped in until the pressure of the reactor is 3.8MPa, and a total of 490g of the mixed monomer is added. After the pressure of the reactor is stable, add 1.5g of potassium persulfate initiator. After the pressure drops, start to add mixed monomers to maintain the reaction pressure at 3.8MPa. After the amount of added monomers reaches 800g, stop adding vinylidene fluoride monomers 959g of polyvinylidene fluoride polymer can be obtained after the taken out emulsion is directly dried.

Claims (9)

1. A perfluorovinyl ether sulfonate, which has a structure shown in formula I:

In formula I, M is Na ⁺ , K ⁺ or NH ₄ ⁺ , X is an integer of 0-2, and Y is an integer of 2-6. 2. The perfluorovinyl ether sulfonate as claimed in claim 1, wherein X is 1 and Y is 2; or X is 0 and Y is 2 or 4. 3. A method for preparing perfluorovinyl ether sulfonate as claimed in claim 1 or 2, the main steps of which are: reacting the compound shown in formula II with the corresponding aqueous inorganic alkali solution at 5°C to 35°C be made of:

Wherein, the pH value of the reaction solution is 7-10. 4. The method according to claim 3, wherein the pH value of the reaction solution is 8-9. 5. The method according to claim 4, wherein the aqueous inorganic alkali solution used is sodium hydroxide aqueous solution, potassium hydroxide aqueous solution or ammonia water, and its concentration is 1wt%-52wt%. 6 . The method according to claim 5 , wherein the concentration of the aqueous inorganic alkali solution is 10wt%˜30wt%. 7. The application of the perfluorovinyl ether sulfonate as claimed in claim 1 or 2 as a reactive surfactant. 8. The application according to claim 7, characterized in that the perfluorovinyl ether sulfonate according to claim 1 or 2 is used as a reactive emulsifier for polymerizable monomer emulsion polymerization. 9. The application according to claim 8, wherein said polymerizable monomers include: tetrafluoroethylene, vinylidene fluoride, hexafluoropropylene, trifluorochloroethylene, trifluorostyrene, perfluoroalkane One or more of vinyl ether, fluorine-containing acrylate, ethylene, propylene, vinyl chloride, styrene, vinyl acetate or acrylate. the

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