A novel fluorocarbon betaine surfactant and a preparation method thereof

Abstract

The application discloses a novel fluorocarbon betaine surfactant and a preparation method thereof, and belongs to the field of surfactant synthesis and application. The preparation method comprises the following steps: (1) adding perfluorohexyl ethyl alcohol and tetrahydrofuran into a reaction container, adding sodium hydride, and then adding chloroacetic acid methyl ester drop by drop; after reaction at a high temperature, an intermediate 1 is obtained; (2) adding N,N-dimethyl-1,3-propanediamine into the intermediate 1, and then performing reaction at a high temperature to obtain an intermediate 2; (3) adding a solvent and a sodium salt into the intermediate 2, and then performing reaction at a high temperature of 70-90 DEG C to obtain the novel fluorocarbon betaine surfactant. The novel fluorocarbon betaine surfactant does not contain perfluorooctanoic acid (PFOA) and perfluorohexane sulfonic acid (PFHxS) substances, is green and environment-friendly, has a small influence on the environment, does not have influences on human reproduction, development and immune system, can effectively stabilize foam, is resistant to high temperature, and can improve the fire extinguishing performance of a foam fire extinguishing agent. In the aspect of oil displacement agents, the novel fluorocarbon betaine surfactant can reduce oil-water interfacial tension, stabilize emulsions and improve the recovery efficiency of crude oil.

Description

TECHNICAL FIELD

[0001] The application relates to the field of surfactant synthesis and application, in particular to a novel fluorocarbon betaine surfactant and a preparation method. BACKGROUND

[0002] The fluorocarbon surfactant has the characteristics of extremely high surface activity, high temperature resistance, good chemical stability and good compatibility, and has been widely and maturely applied in the industry: such as being used as a wetting agent, a leveling agent, an anti-sticking agent and a stain-proofing agent in the paint, coating and ink industries; being used as a light water foam extinguishing agent in the fire-fighting industry; being used as an emulsifying agent, a release agent, an anti-fogging agent and an anti-static agent in a polymer system; being used as a cleaning agent, a fluxing agent and an oxidation inhibitor in the electronic industry; being used as a lubricant, a rinsing additive and a corrosion inhibitor in metal preparation; being used as a bactericide and an anti-fogging agent in agricultural materials; and being used as a chemical oil displacement agent to improve the recovery rate. Perfluorooctanoic acid (PFOA) and perfluorooctyl sulfobetaine (PFOS) are widely used in oil fields, fire fighting and other fields due to excellent performance, but they have been listed as potential POPs substances by the Stockholm Convention Persistent Organic Pollutants (POPs) Review Committee due to low degradability, and have been stopped using, and it is urgent to develop new non-perfluorooctyl fluorocarbon surfactants.

[0003] Publication No. CN102140338A discloses a fluorocarbon surfactant binary compound foam oil displacement system, wherein the fluorocarbon surfactant is a sulfobetaine type fluorocarbon surfactant and an amine oxide type fluorocarbon surfactant, and the structural formula is CF3-(CF2)7-SO2-NH-(CH2)3-N + -(CH3)2-CH2-CH2OH-SO3-. Publication No. CN111333551A discloses a fluorocarbon gemini betaine surfactant, a preparation method and application thereof. The fluorocarbon surfactants disclosed in the two technologies are fluorocarbon surfactants containing sulfonamide groups. The fluorocarbon surfactant with a sulfonamide group is generally prepared from perfluorooctyl sulfonyl fluoride as a starting material, and the subsequent production process is complex, the conditions are harsh, and the yield is low. Publication No. CN105983371A discloses a fluorine-containing carboxylic betaine type surfactant and a preparation method thereof. The structural formula of the fluorocarbon surfactant is R F -A(Z)-B-R1-N + -R3(R4)-R2-COO-, which contains perfluorocarboxylic acid in the structural formula. Perfluorocarbon products are currently listed as banned products.

[0004] In summary, the fluorocarbon surfactant mainly applied at present is the fluorocarbon surfactant containing sulfonamide structure, the reactant material cost of the fluorocarbon surfactant is high, the condition is harsh, the production process is complex, and the environment is easily polluted, so the product is expensive. Therefore, it is urgent to find a fluorocarbon surfactant with simple process, cheap and easily available raw materials and low cost. SUMMARY

[0005] In order to solve the above problems, the application provides a preparation method of a new fluorocarbon betaine surfactant, which can reduce the surface tension and improve the oil recovery efficiency by using low-cost reaction initiators and simple process.

[0006] In order to achieve the above purpose, the application is realized by the following technical scheme:

[0007] A new fluorocarbon betaine surfactant has the structural formula

[0008] The application further discloses a preparation method of the new fluorocarbon betaine surfactant, which specifically comprises the following steps:

[0009] (1) full-fluorinated hexyl ethyl alcohol and tetrahydrofuran are added to a reaction container, sodium hydride is slowly added, methyl chloroacetate is slowly added dropwise under the protection of nitrogen, after warming reaction, tetrahydrofuran is removed under reduced pressure, and water washing is performed until neutral, to obtain an intermediate 1, and the chemical reaction formula is as follows:

[0010]

[0011] (2) N, N-dimethyl-1, 3 propanediamine is added to the intermediate 1, warming reaction is performed, and the generated methanol is discharged, to obtain an intermediate 2, and the chemical reaction formula is as follows:

[0012]

[0013] (3) solvent and sodium salt are added to the intermediate 2, warming is performed to 70-90 DEG C, and after reaction, the new fluorocarbon betaine surfactant is obtained.

[0014] Further, the molar ratio of the full-fluorinated hexyl ethyl alcohol, sodium hydride and methyl chloroacetate in the above step (1) is 1: (1-2): (1-2).

[0015] Preferably, the molar ratio of the full-fluorinated hexyl ethyl alcohol, sodium hydride and methyl chloroacetate in the above step (1) is 1: (1-1.5): (1-1.5).

[0016] Further, the temperature of the warming reaction in step (1) is 40-80 DEG C.

[0017] Further, the molar ratio of the intermediate 1 to N,N-dimethyl-1,3-propanediamine in step (2) is 1:(1-2).

[0018] Preferably, the molar ratio of the intermediate 1 to N,N-dimethyl-1,3-propanediamine in step (2) is 1:(1-1.5).

[0019] Most preferably, the molar ratio of the intermediate 1 to N,N-dimethyl-1,3-propanediamine in step (2) is 1:(1-1.2).

[0020] Further, in step (2), the temperature of the reaction is 70-90℃.

[0021] Further, in step (3), a solvent and sodium salt sodium chloroacetate aqueous solution are added to the intermediate 2 to obtain the novel fluorocarbon betaine surfactant (I), and the specific reaction equation is as shown below:

[0022]

[0023] Further, the molar ratio of the intermediate 2 to sodium chloroacetate aqueous solution is 1:(1-1.5).

[0024] Further, in step (3), a solvent 3 and sodium salt 3-chloro-2-hydroxypropanesulfonic acid sodium are added to the intermediate 2 to obtain the novel fluorocarbon betaine surfactant (II), and the specific reaction equation is as shown below:

[0025]

[0026] Further, the molar ratio of the intermediate 2 to 3-chloro-2-hydroxypropanesulfonic acid sodium aqueous solution is 1:(1-1.5).

[0027] Further, the solvent in step (3) is ethanol or isopropyl alcohol, and the molar mass accounts for 10-40% of the molar mass of the intermediate.

[0028] Further, the reaction temperature in step (3) is 70-90℃.

[0029] The novel fluorocarbon betaine surfactant of the present application is applied in fire foam or oil displacement agent for oil extraction, and the addition concentration is 0.01wt%-0.30wt%.

[0030] The novel fluorocarbon betaine surfactant and the preparation method of the present application have the following beneficial effects:

[0031] (1) The new fluorocarbon betaine surfactant does not contain perfluorooctanoic acid (PFOA) and perfluorohexane sulfonic acid (PFHxS) substances, is green and environmentally friendly, has little impact on the environment, and will not affect human reproduction, development and immune system, etc.

[0032] (2) The raw material used in the present application is perfluorohexyl ethyl alcohol, while the raw material mainly used in existing fluorocarbon surfactants is perfluorooctyl sulfonyl fluoride, perfluorobutyl sulfonyl fluoride, perfluorohexyl ethyl sulfonyl chloride, perfluorooctyl ethyl acrylate, etc. That is, the prior art is synthesized by using sulfonyl fluoride. The price of perfluorohexyl ethyl alcohol is much lower than that of the conventional raw materials, and the oil displacement effect is the same as or even better than that of most existing fluorocarbon surfactants, thus having good economic benefits, energy saving and resource. At the same time, the preparation process of the present application does not use acyl chloride, but directly uses ester amide, which is environmentally friendly.

[0033] (3) The compound of the present application is an ether amide, which can reduce surface tension and has high thermal stability. As a stabilizer for fire-fighting foam, it can effectively stabilize the foam, resist high temperature, and improve the fire extinguishing performance of the foam extinguishing agent.

[0034] (4) The present application has good chemical inertness and can be used in high temperature and strong acid and strong base environment, especially as a tertiary oil displacement agent, which can reduce oil-water interfacial tension, stabilize emulsion and improve oil recovery. DETAILED DESCRIPTION

[0035] In order to enable the personnel in the technical field to better understand the present application, the technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0036] Embodiment 1

[0037] A preparation method of a new fluorocarbon betaine surfactant, comprising the following steps:

[0038] (1) Put perfluorohexylethyl alcohol and tetrahydrofuran into a three-necked flask, start stirring, and reduce the temperature of the system to about 10°C. Slowly add sodium hydride under nitrogen protection, wherein the molar ratio of perfluorohexylethyl alcohol to sodium hydride is 1:1.05, and the amount of tetrahydrofuran is 30% of the weight of perfluorohexylethyl alcohol. After the addition is completed, keep stirring for 30 min, then increase the temperature to 45°C, and keep stirring for 2 h. Then reduce the temperature to about 20°C, slowly drop methyl chloroacetate, wherein the molar ratio of methyl chloroacetate to sodium hydride is 1:1, increase the temperature to 60°C after the dropping is completed, and react for 5 h. Then remove tetrahydrofuran under reduced pressure, and then add distilled water to wash the product until it is neutral to obtain intermediate 1;

[0039] (2) Add N,N-dimethyl-1,3-propanediamine to intermediate 1, wherein the molar ratio of intermediate 1 to N,N-dimethyl-1,3-propanediamine is 1:1.05, increase the temperature to 80°C, and react for 1 h. Then gradually evaporate the generated methanol until no methanol is evaporated, and remove the excess N,N-dimethyl-1,3-propanediamine under reduced pressure to obtain intermediate 2.

[0040] (3) Put intermediate 2 and solvent ethanol into a three-necked flask, quickly add sodium chloroacetate under stirring, and then increase the temperature to 85°C, wherein the molar ratio of intermediate 2 to sodium chloroacetate is 1:1.1, and the amount of ethanol is 20% of the total molar mass of intermediate 2. Keep reacting for 4 h to obtain a new fluorocarbon betaine surfactant I.

[0041] Example 2

[0042] A method for preparing a new fluorocarbon betaine surfactant, comprising the following steps:

[0043] (1) Put perfluorohexylethyl alcohol and tetrahydrofuran into a three-necked flask, start stirring, and reduce the temperature of the system to about 10°C. Slowly add sodium hydride under nitrogen protection, wherein the molar ratio of perfluorohexylethyl alcohol to sodium hydride is 1:2, and the amount of tetrahydrofuran is 30% of the weight of perfluorohexylethyl alcohol. After the addition is completed, keep stirring for 30 min, then increase the temperature to 45°C, and keep stirring for 2 h. Then reduce the temperature to about 20°C, slowly drop methyl chloroacetate, wherein the molar ratio of methyl chloroacetate to sodium hydride is 1:1, increase the temperature to 60°C after the dropping is completed, and react for 5 h. Then remove tetrahydrofuran under reduced pressure, and then add distilled water to wash the product until it is neutral to obtain intermediate 1;

[0044] (2) adding N, N-dimethyl-1, 3-propanediamine to intermediate 1, both of which are added to a three-necked flask, wherein the molar ratio of intermediate 1 to N, N-dimethyl-1, 3-propanediamine is 1:2, the temperature is raised to 80℃, after 1h of reaction, the generated methanol is gradually distilled off until no methanol is distilled off, the excess N, N-dimethyl-1, 3-propanediamine is distilled off under reduced pressure, and intermediate 2 is obtained;

[0045] (3) adding intermediate 2 and solvent ethanol to a three-necked flask, quickly adding an aqueous sodium chloroacetate solution under stirring, and then raising the temperature to 85℃, wherein the molar ratio of intermediate 2 to sodium chloroacetate is 1:1.5, the amount of ethanol is 20% of the total molar mass of intermediate 2, and the reaction is kept for 4h, to obtain the novel fluorocarbon betaine surfactant I.

[0046] Example 3

[0047] A preparation method of a novel fluorocarbon betaine surfactant, comprising the following steps:

[0048] (1) adding perfluorohexylethyl alcohol and tetrahydrofuran to a three-necked flask, starting stirring, and reducing the temperature of the system to about 10℃, slowly adding sodium hydride under nitrogen protection, wherein the molar ratio of perfluorohexylethyl alcohol to sodium hydride is 1:1, and the amount of tetrahydrofuran is 30% of the weight of perfluorohexylethyl alcohol; after the addition is completed, the system is kept stirring for 30min, then the temperature is raised to 45℃, and the system is kept stirring for 2h; then the temperature is reduced to about 20℃, and methyl chloroacetate is slowly added dropwise, wherein the molar ratio of methyl chloroacetate to sodium hydride is 1:1.2; after the dropwise addition is completed, the temperature is raised to 60℃, and the reaction is kept for 5h; then tetrahydrofuran is removed under reduced pressure, and distilled water is added to wash the product until it is neutral, to obtain intermediate 1;

[0049] (2) adding N, N-dimethyl-1, 3-propanediamine to intermediate 1, both of which are added to a three-necked flask, wherein the molar ratio of intermediate 1 to N, N-dimethyl-1, 3-propanediamine is 1:1.5, the temperature is raised to 80℃, after 1h of reaction, the generated methanol is gradually distilled off until no methanol is distilled off, the excess N, N-dimethyl-1, 3-propanediamine is distilled off under reduced pressure, and intermediate 2 is obtained;

[0050] (3) adding intermediate 2 and solvent ethanol to a three-necked flask, quickly adding an aqueous sodium chloroacetate solution under stirring, and then raising the temperature to 85℃, wherein the molar ratio of intermediate 2 to sodium chloroacetate is 1:1, the amount of ethanol is 20% of the total molar mass of intermediate 2, and the reaction is kept for 4h, to obtain the novel fluorocarbon betaine surfactant I.

[0051] Example 4

[0052] A preparation method of a novel fluorocarbon betaine surfactant, comprising the following steps:

[0053] (1) Put perfluorohexylethyl alcohol and tetrahydrofuran into a three-necked flask, start stirring, and reduce the temperature of the system to about 10°C. Slowly add sodium hydride under nitrogen protection, wherein the molar ratio of perfluorohexylethyl alcohol to sodium hydride is 1:1.5, and the amount of tetrahydrofuran is 30% of the weight of perfluorohexylethyl alcohol. After the addition is completed, keep stirring for 30 min, then increase the temperature to 45°C, and keep stirring for 2 h. Then reduce the temperature to about 20°C, slowly drop methyl chloroacetate, wherein the molar ratio of methyl chloroacetate to sodium hydride is 1:1, increase the temperature to 60°C after the dropping is completed, and react for 5 h. Then remove tetrahydrofuran under reduced pressure, add distilled water, and wash the product until it is neutral to obtain intermediate 1;

[0054] (2) Add N,N-dimethyl-1,3-propanediamine to intermediate 1, wherein the molar ratio of intermediate 1 to N,N-dimethyl-1,3-propanediamine is 1:1.1, increase the temperature to 80°C, and react for 1 h. Then gradually remove the generated methanol until no methanol is generated, remove the excess N,N-dimethyl-1,3-propanediamine under reduced pressure to obtain intermediate 2.

[0055] (3) Put intermediate 2 and solvent ethanol into a three-necked flask, quickly add sodium chloroacetate under stirring, then increase the temperature to 85°C, wherein the molar ratio of intermediate 2 to sodium chloroacetate is 1:1.3, and the amount of ethanol is 20% of the total molar mass of intermediate 2, and keep reacting for 4 h to obtain a new fluorocarbon betaine surfactant I.

[0056] Example 5

[0057] A method for preparing a new fluorocarbon betaine surfactant, comprising the following steps:

[0058] (1) Put perfluorohexylethyl alcohol and tetrahydrofuran into a three-necked flask, start stirring, and reduce the temperature of the system to about 10°C. Slowly add sodium hydride under nitrogen protection, wherein the molar ratio of perfluorohexylethyl alcohol to sodium hydride is 1:1.05, and the amount of tetrahydrofuran is 30% of the weight of perfluorohexylethyl alcohol. After the addition is completed, keep stirring for 30 min, then increase the temperature to 45°C, and keep stirring for 2 h. Then reduce the temperature to about 20°C, slowly drop methyl chloroacetate, wherein the molar ratio of methyl chloroacetate to sodium hydride is 1:1, increase the temperature to 60°C after the dropping is completed, and react for 5 h. Then remove tetrahydrofuran under reduced pressure, add distilled water, and wash the product until it is neutral to obtain intermediate 1;

[0059] (2) To the intermediate 1, add N, N-dimethyl-1, 3-propanediamine, both of which are added to a three-necked flask, wherein the molar ratio of intermediate 1 to N, N-dimethyl-1, 3-propanediamine is 1:1.05, and the temperature is raised to 80°C, after 1h of reaction, the generated methanol is gradually distilled off until no methanol is distilled off, and the excess N, N-dimethyl-1, 3-propanediamine is distilled off under reduced pressure to obtain intermediate 2;

[0060] (3) Add intermediate 2 and solvent ethanol to a three-necked flask, quickly add 3-chloro-2-hydroxy-propanesulfonic acid sodium under stirring, and then raise the temperature to 85°C, wherein the molar ratio of intermediate 2 to 3-chloro-2-hydroxy-propanesulfonic acid sodium is 1:1.1, and the amount of ethanol is 20% of the total molar mass of intermediate 2, and the reaction is kept for 4h to obtain a new fluorocarbon betaine surfactant II.

[0061] Example 6

[0062] A method for preparing a new fluorocarbon betaine surfactant, comprising the following steps:

[0063] (1) Add perfluorohexyl ethyl alcohol and tetrahydrofuran to a three-necked flask, start stirring, and reduce the temperature of the system to about 10°C, slowly add sodium hydride under nitrogen protection, wherein the molar ratio of perfluorohexyl ethyl alcohol to sodium hydride is 1:2, and the amount of tetrahydrofuran is 30% of the weight of perfluorohexyl ethyl alcohol. After adding, keep stirring for 30min, then raise the temperature to 45°C, and keep stirring for 2h. Then reduce the temperature to about 20°C, slowly drop methyl chloroacetate, wherein the molar ratio of methyl chloroacetate to sodium hydride is 1:1, after dropping, raise the temperature to 60°C, and react for 5h. Then remove tetrahydrofuran under reduced pressure, and then add distilled water to wash the product to neutral to obtain intermediate 1;

[0064] (2) To the intermediate 1, add N, N-dimethyl-1, 3-propanediamine, both of which are added to a three-necked flask, wherein the molar ratio of intermediate 1 to N, N-dimethyl-1, 3-propanediamine is 1:2, and the temperature is raised to 80°C, after 1h of reaction, the generated methanol is gradually distilled off until no methanol is distilled off, and the excess N, N-dimethyl-1, 3-propanediamine is distilled off under reduced pressure to obtain intermediate 2;

[0065] (3) Add intermediate 2 and solvent ethanol to a three-necked flask, quickly add 3-chloro-2-hydroxy-propanesulfonic acid sodium under stirring, and then raise the temperature to 85°C, wherein the molar ratio of intermediate 2 to 3-chloro-2-hydroxy-propanesulfonic acid sodium is 1:1.5, and the amount of ethanol is 20% of the total molar mass of intermediate 2, and the reaction is kept for 4h to obtain a new fluorocarbon betaine surfactant II.

[0066] Example 7

[0067] A preparation method of a novel fluorocarbon betaine surfactant, comprising the following steps:

[0068] (1) Put perfluorohexyl ethyl alcohol and tetrahydrofuran into a three-necked flask, start stirring, and reduce the system temperature to about 10°C. Slowly add sodium hydride under nitrogen protection, wherein the molar ratio of perfluorohexyl ethyl alcohol to sodium hydride is 1:1.2, and the amount of tetrahydrofuran accounts for 30% of the weight of perfluorohexyl ethyl alcohol. After adding, keep stirring for 30 min, then increase the temperature to 45°C, and keep stirring for 2 h. Then reduce the temperature to about 20°C, slowly drop methyl chloroacetate, wherein the molar ratio of methyl chloroacetate to sodium hydride is 1:1. After dropping, increase the temperature to 60°C, react for 5 h, then remove tetrahydrofuran under reduced pressure, and then add distilled water to wash the product to neutral to obtain intermediate 1;

[0069] (2) Add N,N-dimethyl-1,3-propanediamine to intermediate 1, wherein the molar ratio of intermediate 1 to N,N-dimethyl-1,3-propanediamine is 1:1.5, increase the temperature to 80°C, react for 1 h, then gradually evaporate the generated methanol until no methanol is evaporated, and then remove the excess N,N-dimethyl-1,3-propanediamine under reduced pressure to obtain intermediate 2;

[0070] (3) Put intermediate 2 and solvent ethanol into a three-necked flask, quickly add 3-chloro-2-hydroxy-propanesulfonic acid sodium under stirring, and then increase the temperature to 85°C, wherein the molar ratio of intermediate 2 to 3-chloro-2-hydroxy-propanesulfonic acid sodium is 1:1, and the amount of ethanol accounts for 20% of the total molar mass of intermediate 2. Keep reacting for 4 h to obtain the novel fluorocarbon betaine surfactant II.

[0071] Example 8

[0072] A preparation method of a novel fluorocarbon betaine surfactant, comprising the following steps:

[0073] (1) Put perfluorohexyl ethyl alcohol and tetrahydrofuran into a three-necked flask, start stirring, and reduce the system temperature to about 10°C. Slowly add sodium hydride under nitrogen protection, wherein the molar ratio of perfluorohexyl ethyl alcohol to sodium hydride is 1:1.5, and the amount of tetrahydrofuran accounts for 30% of the weight of perfluorohexyl ethyl alcohol. After adding, keep stirring for 30 min, then increase the temperature to 45°C, and keep stirring for 2 h. Then reduce the temperature to about 20°C, slowly drop methyl chloroacetate, wherein the molar ratio of methyl chloroacetate to sodium hydride is 1:1. After dropping, increase the temperature to 60°C, react for 5 h, then remove tetrahydrofuran under reduced pressure, and then add distilled water to wash the product to neutral to obtain intermediate 1;

[0074] (2) adding N,N-dimethyl-1,3-propanediamine to intermediate 1, both of which are added to a three-necked flask, wherein the molar ratio of intermediate 1 to N,N-dimethyl-1,3-propanediamine is 1:1.1, and the temperature is raised to 80°C, after 1h of reaction, the generated methanol is gradually distilled off until no methanol is distilled off, and the excess N,N-dimethyl-1,3-propanediamine is distilled off under reduced pressure to obtain intermediate 2;

[0075] (3) adding intermediate 2 and solvent ethanol to a three-necked flask, and then adding 3-chloro-2-hydroxy-propanesulfonic acid sodium under stirring, and then raising the temperature to 85°C, wherein the molar ratio of intermediate 2 to 3-chloro-2-hydroxy-propanesulfonic acid sodium is 1:1.3, and the amount of ethanol is 20% of the total molar mass of intermediate 2, and then reacting for 4h to obtain the novel fluorocarbon betaine surfactant II.

[0076] 1. Performance determination

[0077] Sample: The products I and II in examples 1-8 are prepared into 0.1%, 0.05% and 0.01% aqueous solvents, and commercially available perfluorooctyl sulfonate betaine surfactant (PFOS), commercially available perfluorooctanoic acid surfactant (PFOA) and commercially available sulfonamide type fluorocarbon surfactant.

[0078] Detection basis: The surface tension of the novel fluorocarbon betaine surfactant is determined according to the ring method in GB / T 22237-2008, and the interfacial tension of the novel fluorocarbon betaine surfactant is determined according to GB / T 38722-2020.

[0079] The test results are shown in Table 1:

[0080] Table 1 Surface tension and interfacial tension of each substance

[0081]

[0082]

[0083] As can be seen from Table 1, the interfacial tension and surface tension of the novel fluorocarbon betaine surfactant I obtained from examples 1-4 are close to the performance of imported PFOA, the interfacial tension and surface tension of the novel fluorocarbon betaine surfactant II obtained from examples 5-8 are close to the performance of imported PFOS, and the surface tension is much lower than that of the commercially available sulfonamide type fluorocarbon surfactant, and the surface activity is better.

[0084] In order to characterize the oil displacement efficiency of the present application, the novel fluorocarbon betaine surfactant I of example 2 and the novel fluorocarbon betaine surfactant II of example 6 are used to carry out oil displacement experiments, and the results are shown in Table 2.

[0085] Table 2 Oil displacement effect

[0086]

[0087] As shown in Table 2, the oil displacement effects of the two structures of fluorocarbon betaine surfactants of the present application are close, and both can improve the recovery rate, which can be improved by 20%-25%.

[0088] The oil displacement experiments of the present application (Example 2 and Example 6) and the existing commercially available products were compared at a 0.2% oil displacement concentration, and the data obtained are shown in Table 3:

[0089] Table 3 Oil displacement effects of the present application and existing products

[0090]

[0091] As shown in Table 3, the existing common sulfonamide type fluorocarbon surfactant as an oil displacement agent can improve the recovery rate, and the existing fluorocarbon surfactant has a recovery rate improvement range of <10%. The two structures of fluorocarbon betaine surfactants obtained by the present application have a recovery rate improvement of >22%, which achieves unexpected effects compared with the prior art, and has significant progress.

[0092] In this document, reference to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase "in an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. It is expressly understood that any of the embodiments described herein can be combined with any of the other embodiments unless specifically noted otherwise.

[0093] Finally, it should be noted that: the embodiments disclosed by the present application are only the preferred embodiments of the present application, and are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand; it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A novel fluorocarbon betaine surfactant characterized by: The structural formula is 。 2. A method of preparing a novel fluorocarbon betaine surfactant, characterized by: The method comprises the following steps: (1) adding perfluorohexyl ethyl alcohol and tetrahydrofuran into a reaction container, slowly adding sodium hydride, slowly dropping chloroacetic acid methyl ester under nitrogen protection, and then performing a warming reaction, removing tetrahydrofuran under reduced pressure, washing with water until neutral, and obtaining an intermediate 1; (2) adding N, N-dimethyl-1, 3 propanediamine into the intermediate 1, performing a warming reaction, and removing generated methanol to obtain an intermediate 2; (3) adding a solvent and sodium salt into the intermediate 2, and then performing a warming reaction at 70-90 DEG C to obtain a new fluorocarbon betaine surfactant.

3. The preparation method of the novel fluorobetaine surfactant according to claim 2, characterized in that: The molar ratio of perfluorohexyl ethyl alcohol, sodium hydride and chloroacetic acid methyl ester in step (1) is 1: (1-2): (1-2).

4. The preparation method of the novel fluorobetaine surfactant according to claim 2, characterized in that: The temperature of the warming reaction in step (1) is 40-80 DEG C.

5. The method for preparing the novel fluorobetaine surfactant according to claim 2, characterized in that: The molar ratio of the intermediate 1 and N, N-dimethyl-1, 3 propanediamine in step (2) is 1: (1-2).

6. The method for preparing the novel fluorobetaine surfactant according to claim 2, characterized in that: The temperature of the warming reaction in step (2) is 70-90 DEG C.

7. The method for preparing the novel fluorobetaine surfactant according to claim 2, characterized in that: In step (3), a solvent and sodium chloroacetate aqueous solution are added into the intermediate 2 to obtain a new fluorocarbon betaine surfactant (I).

8. The method for preparing the novel fluorobetaine surfactant according to claim 7, characterized in that: The molar ratio of the intermediate 2 and sodium chloroacetate aqueous solution is 1: (1-1.5).

9. The method for preparing the novel fluorobetaine surfactant according to claim 2, characterized in that: In step (3), a solvent and sodium 3-chloro-2-hydroxypropanesulfonate are added into the intermediate 2 to obtain a new fluorocarbon betaine surfactant (II).

10. The method for preparing the novel fluorobetaine surfactant according to claim 9, characterized in that: The molar ratio of the intermediate 2 and sodium 3-chloro-2-hydroxypropanesulfonate aqueous solution is 1: (1-1.5).

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