A method for synthesizing sodium perfluorohexylethylsulfonate

Abstract

The application belongs to the technical field of fluorocarbon surfactant application, and particularly discloses a synthesis method of sodium perfluorohexylethyl sulfonate, which comprises the following steps: (1) under the protection of nitrogen, perfluorohexylethyl iodine, potassium thiocyanate and a phase transfer catalyst are added into water and stirred to react, an organic layer is separated, and rotary evaporation is performed to obtain perfluorohexylethyl thiocyanate; (2) the perfluorohexylethyl thiocyanate is added into water and heated, and then chlorine is continuously introduced to stir to react, and filtration separation is performed to obtain perfluorohexylethyl sulfuryl chloride; and (3) the perfluorohexylethyl sulfuryl chloride is added into sodium hydroxide water solution drop by drop, and stirred to react, and after filtration, water washing, recrystallization and drying, the sodium perfluorohexylethyl sulfonate is obtained. The sodium perfluorohexylethyl sulfonate has high yield and high purity, has excellent surface activity, has excellent compounding performance with a hydrocarbon surfactant, has very good thermal stability, salt resistance and chemical stability, and meets the environmental protection requirements.

Description

Technical Field

[0001] This invention belongs to the field of fluorocarbon surfactant application technology, specifically relating to a method for synthesizing sodium perfluorohexyl ethyl sulfonate. Background Technology

[0002] Fluorocarbon surfactants are surfactants with hydrophobic and oleophobic carbon-fluorine segments formed by replacing all or part of the oxygen atoms in the carbon-oxygen chain of nonpolar groups with fluorine atoms. They are currently the most effective type of surfactant, possessing high chemical activity, high thermal stability, high chemical stability, and hydrophobic and oleophobic properties. They are widely used in many fields such as detergents, food, cosmetics, petrochemicals, coatings, plastics, rubber, fire protection, photosensitive materials, and medical devices.

[0003] Currently, the most widely used fluorocarbon surfactants are perfluorooctyl sulfonate and perfluorooctanoate. They are widely used in textiles, carpets, paper, coatings, fire-fighting foam, imaging materials, aviation hydraulic oils and other fields. However, these two salts are among the most difficult organic pollutants to degrade, with a high bioaccumulation capacity, which leads to environmental pollution problems. It is necessary to find suitable alternatives.

[0004] Therefore, based on the above problems, the present invention provides a method for synthesizing sodium perfluorohexyl ethyl sulfonate. Summary of the Invention

[0005] Objective of this invention: The technical problem to be solved by this invention is to provide a method for synthesizing sodium perfluorohexyl ethyl sulfonate with high yield. The synthesized sodium perfluorohexyl ethyl sulfonate, as an anionic fluorocarbon surfactant, has excellent performance and meets current environmental protection requirements. It can replace existing perfluorooctyl sulfonate and perfluorooctanoate fluorocarbon surfactants.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0007] A method for synthesizing sodium perfluorohexyl ethyl sulfonate includes the following steps:

[0008] (1) Under nitrogen protection, add measured amounts of perfluorohexyl ethyl iodine, potassium thiocyanate and phase transfer catalyst to the reaction flask, add deionized water and heat and stir for 5-6 hours, then separate the organic layer, wash with deionized water and separate 4-5 times, place in a rotary evaporator to remove water, and obtain perfluorohexyl ethyl thiocyanate.

[0009] (2) Add the perfluorohexyl ethyl thiocyanate obtained in step (1) into the deoxygenated high-pressure reactor, add deionized water and heat to 90-100℃, continuously pass chlorine gas for 10h, continue stirring the reaction for 3-4h after the addition is completed, and then cool down and discharge the material.

[0010] (3) Rinse the product obtained in step (2) with deionized water and separate the organic layer using a separatory funnel. Repeat 4-5 times. Add toluene solvent to dissolve the product, rinse with deionized water and separate the organic layer. Repeat 2-3 times. Then remove the solvent by rotary evaporation to obtain the product, i.e., perfluorohexyl ethyl sulfonyl chloride.

[0011] (4) Add a measured amount of sodium hydroxide aqueous solution to a round-bottom flask, and add the perfluorohexyl ethyl sulfonyl chloride obtained in step (3) dropwise in an ice-water bath reaction system. The dropwise addition time is maintained at 2 h. After the dropwise addition is completed, stir the reaction for 20 h, filter to obtain filtrate, cool the filtrate, filter it to obtain filter cake, wash the filter cake with water, recrystallize it, and dry it to obtain sodium perfluorohexyl ethyl sulfonate.

[0012] In this technical solution, the phase transfer catalyst is methyltrioctylammonium chloride.

[0013] In this technical solution, the molar ratio of perfluorohexyl ethyl iodine, potassium thiocyanate and phase transfer catalyst in step (1) is 1:1-3:0.05-0.1.

[0014] In this technical solution, the heating temperature in step (1) is 135-145℃.

[0015] In this technical solution, the temperature of the ice water bath in step (4) is -5℃ to 10℃.

[0016] Compared with the prior art, the beneficial effects of the method for synthesizing sodium perfluorohexyl ethyl sulfonate of the present invention are as follows: the sodium perfluorohexyl ethyl sulfonate prepared by the method of the present invention has high yield and high purity, excellent surface activity, excellent compounding performance with hydrocarbon surfactants, and very good thermal stability, salt resistance and chemical stability. It can replace perfluorooctyl sulfonate and perfluorooctyl fluorocarbon surfactants, thus meeting environmental protection requirements. Detailed Implementation

[0017] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0018] Example 1

[0019] The present invention provides a method for synthesizing sodium perfluorohexyl ethyl sulfonate, comprising the following steps:

[0020] (1) Under nitrogen protection, add 47.5g of perfluorohexyl ethyl iodine, 9.7g of potassium thiocyanate and 4.1g of methyltrioctyl ammonium chloride to the reaction flask, add deionized water, heat to 135-145℃ and stir for 5h, then separate the organic layer, wash with deionized water and separate 4-5 times, place in a rotary evaporator to remove water, and obtain perfluorohexyl ethyl thiocyanate;

[0021] (2) Add the perfluorohexyl ethyl thiocyanate obtained in step (1) into the deoxygenated high-pressure reactor, add deionized water and heat to 90°C, continuously pass chlorine gas for 10 hours, continue stirring and reacting for 4 hours after the addition is complete, and then cool down and discharge the material.

[0022] (3) The product obtained in step (2) is rinsed with deionized water and the organic layer is separated using a separatory funnel. This process is repeated 4 times. Toluene solvent is added to dissolve the product. The product is rinsed with deionized water and the organic layer is separated. This process is repeated 3 times. Then the solvent is removed by rotary evaporation to obtain the product, which is perfluorohexyl ethyl sulfonyl chloride.

[0023] (4) Add a measured amount of sodium hydroxide aqueous solution to a round-bottom flask, and add the perfluorohexyl ethyl sulfonyl chloride obtained in step (3) dropwise in an ice-water bath reaction system at -5℃ to 10℃. The dropwise addition time is maintained at 2 h. After the dropwise addition is completed, stir the reaction for 20 h, filter to obtain filtrate, cool the filtrate, filter by suction to obtain filter cake, wash the filter cake with water, recrystallize and dry to obtain sodium perfluorohexyl ethyl sulfonate with a yield of 89.9%.

[0024] Example 2

[0025] The present invention provides a method for synthesizing sodium perfluorohexyl ethyl sulfonate, comprising the following steps:

[0026] (1) Under nitrogen protection, add 47.5g of perfluorohexylethyl iodine, 19.4g of potassium thiocyanate and 2.1g of methyltrioctyl ammonium chloride to the reaction flask, add deionized water, heat to 135-145℃ and stir for 6h, then separate the organic layer, wash with deionized water and separate 4-5 times, place in a rotary evaporator to remove water, and obtain perfluorohexylethyl thiocyanate;

[0027] (2) Add the perfluorohexyl ethyl thiocyanate obtained in step (1) into the deoxygenated high-pressure reactor, add deionized water and heat to 95°C, continuously pass chlorine gas for 10 hours, continue stirring and reacting for 3 hours after the addition is completed, and then cool down and discharge the material.

[0028] (3) The product obtained in step (2) is rinsed with deionized water and the organic layer is separated using a separatory funnel. This process is repeated 4 times. Toluene solvent is added to dissolve the product. The product is rinsed with deionized water and the organic layer is separated. This process is repeated 3 times. Then the solvent is removed by rotary evaporation to obtain the product, which is perfluorohexyl ethyl sulfonyl chloride.

[0029] (4) Add a measured amount of sodium hydroxide aqueous solution to a round-bottom flask, and add the perfluorohexyl ethyl sulfonyl chloride obtained in step (3) dropwise in an ice-water bath reaction system at -5℃ to 10℃. The dropwise addition time is maintained at 2 h. After the dropwise addition is completed, stir the reaction for 20 h, filter to obtain filtrate, cool the filtrate, filter by suction to obtain filter cake, wash the filter cake with water, recrystallize and dry to obtain sodium perfluorohexyl ethyl sulfonate with a yield of 90.2%.

[0030] Example 3

[0031] The present invention provides a method for synthesizing sodium perfluorohexyl ethyl sulfonate, comprising the following steps:

[0032] (1) Under nitrogen protection, add 47.5g of perfluorohexylethyl iodine, 29.1g of potassium thiocyanate and 3.3g of methyltrioctyl ammonium chloride to the reaction flask, add deionized water, heat to 135-145℃ and stir for 5-6h, then separate the organic layer, wash with deionized water and separate 4-5 times, place in a rotary evaporator to remove water, and obtain perfluorohexylethyl thiocyanate;

[0033] (2) Add the perfluorohexyl ethyl thiocyanate obtained in step (1) into the deoxygenated high-pressure reactor, add deionized water and heat to 100°C, continuously pass chlorine gas for 10 hours, continue stirring and reacting for 3 hours after the addition is complete, and then cool down and discharge the material.

[0034] (3) The product obtained in step (2) is rinsed with deionized water and the organic layer is separated using a separatory funnel. This is repeated 5 times. Toluene solvent is added to dissolve the product. The product is rinsed with deionized water and the organic layer is separated. This is repeated 2 times. Then the solvent is removed by rotary evaporation to obtain the product, which is perfluorohexyl ethyl sulfonyl chloride.

[0035] (4) Add a measured amount of sodium hydroxide aqueous solution to a round-bottom flask, and add the perfluorohexyl ethyl sulfonyl chloride obtained in step (3) dropwise in an ice-water bath reaction system at -5℃ to 10℃. The dropwise addition time is maintained at 2 h. After the dropwise addition is completed, stir the reaction for 20 h, filter to obtain filtrate, cool the filtrate, filter by suction to obtain filter cake, wash the filter cake with water, recrystallize and dry to obtain sodium perfluorohexyl ethyl sulfonate with a yield of 90.4%.

[0036] The method for synthesizing sodium perfluorohexyl ethyl sulfonate according to Example 1, Example 2, or Example 3 of this invention provides a method for synthesizing sodium perfluorohexyl ethyl sulfonate with high yield and high purity. It has excellent surface activity, excellent compatibility with hydrocarbon surfactants, and very good thermal stability, salt resistance, and chemical stability. It can replace perfluorooctyl sulfonate and perfluorooctyl fluorocarbon surfactants, thus meeting environmental protection requirements.

[0037] The above are preferred embodiments of the present invention and are only applicable to help understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on this embodiment. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method of synthesizing sodium perfluorohexylethylsulfonate, characterized by: It comprises the following steps: (1) under the protection of nitrogen, a metering perfluorohexyl ethyl iodine, potassium thiocyanate and phase transfer catalyst are added into a reaction flask, deionized water is added to stir the reaction at elevated temperature for 5-6h, then the organic layer is separated, washed with deionized water and separated for 4-5 times, and placed in a rotary evaporator to remove water, to obtain perfluorohexyl ethyl thiocyanate; (2) the perfluorohexyl ethyl thiocyanate obtained in step (1) is added to an oxygen-free high-pressure reactor, deionized water is added to heat to 90-100℃, and chlorine is continuously introduced for 10h, after the addition is completed, the reaction is continued to stir for 3-4h, and the temperature is lowered to discharge; (3) the product obtained in step (2) is washed with deionized water, and the organic layer is separated with a separatory funnel, repeated for 4-5 times, and the product is dissolved with toluene solvent, washed with deionized water and separated into organic layer, repeated for 2-3 times, then the solvent is removed by rotary evaporation to obtain the product, i.e. perfluorohexyl ethyl sulfonyl chloride; (4) a metering sodium hydroxide aqueous solution is added to a round-bottom flask, and the perfluorohexyl ethyl sulfonyl chloride obtained in step (3) is added dropwise in an ice water bath reaction system, the dropwise time is kept at 2h, after the dropwise addition is completed, the reaction is stirred for 20h, the filtrate is obtained by filtration, the filtrate is cooled, suction filtered to obtain the filter cake, and the filter cake is washed with water, recrystallized and dried to obtain sodium perfluorohexyl ethyl sulfonate; In step (1), the molar ratio of perfluorohexyl ethyl iodine, potassium thiocyanate and phase transfer catalyst is 1:1-3:0.05-0.1; the elevated temperature in step (1) is 135-145℃; and the phase transfer catalyst is methyltrioctylammonium chloride; The ice water bath temperature in step (4) is-5℃ to-10℃.