Amphoteric surfactant as well as preparation method and application thereof

Abstract

The invention relates to an ampholytic surfactant as well as a preparation method and application thereof. The ampholytic surfactant has a structure as shown in a formula (I), has good solubilizing performance on organic matters, can be applied under acidic and alkaline conditions, has wider application fields, and can be applied to the fields of industrial cleaning, oil fields, textile assistants and the like; and the preparation process is simple, does not need subsequent purification treatment, does not generate toxic and harmful byproducts in the preparation process, and is green, safe and high in conversion rate.

Description

Technical Field

[0001] The present invention relates to the technical field of surfactants, and in particular to an amphoteric surfactant and a preparation method and application thereof. Background Art

[0002] N-alkyl-β-aminopropionic acid surfactant is a mild, low-irritation green surfactant with good foaming properties, acid and alkali resistance, good compatibility with other surfactants, and easy biodegradation. Therefore, it is widely used in industrial cleaning, oilfield chemistry, personal washing and cosmetics, and antistatic applications.

[0003] N-alkyl amino acid surfactants mainly construct amino acid structures through fatty amines and acrylic compounds (Lan Yunjun, Bao Li. Synthesis of N-alkyl-β-aminopropionic acid [J]. Leather Chemical Industry. 19 (2): 21-23). ​​At present, the main industrial production process of this product on the market is to use fatty amines and fatty acid methyl esters to react, and then hydrolyze to obtain the product. CN111072557A discloses an amide-type Gemini surfactant and a preparation method thereof. The process is relatively cumbersome and there is a problem of residual methanol by-products. CN104193636A discloses a method for preparing β-aminopropionic acid amphoteric surfactants. The solubilization of the prepared β-aminopropionic acid amphoteric surfactants is not particularly excellent, which affects its scope of application.

[0004] Therefore, it is of great significance to provide an amphoteric surfactant with good solubilizing performance and acid and alkali resistance. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides an amphoteric surfactant and a preparation method and application thereof. The amphoteric surfactant of the present invention has good solubilization performance for organic matter and is applicable under both acidic and alkaline conditions; its preparation process is simple, green and safe, and has a high conversion rate.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides an amphoteric surfactant having a structure shown in formula (I):

[0008]

[0009] In formula (I), Ar is selected from phenyl or naphthyl;

[0010] R is selected from a C4-C12 straight chain or branched alkyl group; R1 is selected from H or methyl;

[0011] m is an integer of 0-2; M is Na or K.

[0012] In the present invention, C4-C12 may be C4, C5, C6, C7, C8, C9, C10, C11 or C12.

[0013] m can be 0, 1 or 2.

[0014] The aromatic-containing amphoteric surfactant provided in the present invention has excellent wetting power, foam and emulsifying properties, and also has good solubilization. Furthermore, the amphoteric surfactant still has a good solubilization effect under strong acidic conditions, and also has good alkali resistance, and still dissolves transparently under strong alkalinity, and has good market application prospects.

[0015] In a second aspect, the present invention provides a method for preparing the amphoteric surfactant as described in the first aspect, the preparation method comprising the following steps:

[0016] The aromatic-containing organic amine compound is reacted with an acrylic compound to obtain the solubilizing amphoteric surfactant.

[0017] The synthesis process of the amphoteric surfactant provided by the present invention is an atom-economical reaction, the preparation process is simple, no subsequent purification treatment is required, no toxic or harmful by-products are generated during the preparation process, the process is green and safe, and the conversion rate is high.

[0018] Preferably, the aromatic-containing organic amine compound has a structure described by formula (II):

[0019]

[0020] In formula (II), Ar is selected from phenyl or naphthyl, R is selected from C4-C12 straight chain or branched alkyl, and m is an integer of 0-2.

[0021] In the present invention, C4-C12 may be C4, C5, C6, C7, C8, C9, C10, C11 or C12.

[0022] m can be 0, 1 or 2.

[0023] Preferably, the acrylic compound is acrylic acid or methacrylic acid.

[0024] The present invention selects specific acrylic acid compounds as reaction raw materials, avoids the use of methyl acrylate, not only effectively avoids the generation of methanol by-products, but also reduces economic costs, and makes the reaction more green and safe.

[0025] The synthesis route of the amphoteric surfactant provided by the present invention is as follows:

[0026]

[0027] Ar is selected from phenyl or naphthyl;

[0028] R is selected from a C4-C12 straight chain or branched alkyl group; R1 is selected from H or methyl; M is Na or K.

[0029] Preferably, the molar ratio of the aromatic organic amine compound to the acrylic compound is 1:(1.80-2.10), for example, 1:1.84, 1:1.88, 1:1.92, 1:1.96, 1:2.00, 1:2.04 or 1:2.08, and is not limited to the listed values. Other unlisted data within the numerical range are also applicable.

[0030] Preferably, the reaction is carried out in a solvent.

[0031] Preferably, the solvent is a protic solvent.

[0032] Preferably, the protic solvent comprises water.

[0033] Preferably, the water includes any one of tap water, distilled water, purified water or deionized water, or a combination of at least two of them.

[0034] The present invention uses water as the reaction solvent, avoiding the use of organic solvents, making the reaction more economical, green and safe; at the same time, the addition of protic solvents can further promote the occurrence of the reaction, not only shortening the reaction time, but also further improving the conversion rate of the reaction.

[0035] Preferably, the reaction is carried out in the presence of a catalyst.

[0036] Preferably, the catalyst comprises any one of NaOH, KOH, Na2CO3 or K2CO3, or a combination of at least two thereof.

[0037] The present invention selects a specific inorganic base as a catalyst, which is economical and easy to obtain, and the reaction does not introduce irrelevant impurity elements. At the same time, after the reaction is completed, there is no need to perform impurity removal steps such as filtration, which simplifies the operation process. At the same time, it has a good catalytic effect and can obtain a target product with a high conversion rate (the conversion rate is above 92%).

[0038] Preferably, the amount of the catalyst added is 0.5-2% by mass of the aromatic organic amine compound, for example, it can be 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8% or 2.0%, not limited to the listed values, and other unlisted data within the numerical range are also applicable.

[0039] In the present invention, when the catalyst is added in an amount of 0.5-2% of the mass of the aromatic organic amine compound, it has a good catalytic effect. When it is not added or is less than 0.5%, its catalytic effect is poor and is not conducive to the reaction; when it is added in an amount greater than 2%, its catalytic effect on the reaction will not be significantly improved.

[0040] Preferably, the reaction temperature is 75-100°C, for example, 78°C, 80°C, 82°C, 85°C, 88°C, 90°C, 92°C, 95°C, 98°C or 100°C, not limited to the listed values, and other unlisted data within the numerical range are also applicable.

[0041] Preferably, the reaction time is 5-15 h, for example, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h, 13 h, 14 h or 15 h, not limited to the listed values, and other unlisted data within the numerical range are also applicable.

[0042] Preferably, after the reaction is completed, the pH is adjusted to 8.0-9.0, for example, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9 or 9.0, not limited to the listed values, and other unlisted data within the numerical range are also applicable.

[0043] In the present invention, the obtained amphoteric surfactant is a weakly alkaline transparent solution, which is economical and convenient and can be well applied in actual production.

[0044] Preferably, the pH adjustment is performed using a base.

[0045] Preferably, the base comprises NaOH and / or KOH.

[0046] Preferably, the preparation method specifically comprises the following steps:

[0047] The aromatic organic amine compound, the catalyst and the solvent are mixed, stirred and heated to 75-100° C., and the acrylic compound is added. After the addition is completed, the reaction is carried out at 75-100° C. for 5-15 hours. After the reaction is completed, the pH is adjusted to 8.0-9.0 with alkali to obtain the solubilizing amphoteric surfactant;

[0048] The molar ratio of the aromatic-containing organic amine compound to the acrylic compound is 1:(1.80-2.10);

[0049] The added amount of the catalyst is 0.5-2% of the mass of the aromatic-containing organic amine compound.

[0050] In a third aspect, the present invention provides a use of the amphoteric surfactant as described in the first aspect in industrial cleaning, lubricants, environmental management or personal care.

[0051] The solubilizing amphoteric surfactant prepared by the specific preparation method in the present invention is not only green and safe, and can be used in the fields of industrial cleaning, agrochemicals, personal care and environmental management, but also has good solubilizing performance for organic matter, and can be well applied to the fields of industrial cleaning, oil field development and lubricants, greatly expanding the scope of application and having good application prospects.

[0052] Compared with the prior art, the present invention has at least the following beneficial effects:

[0053] The amphoteric surfactant provided by the invention has good solubilizing performance for organic matter and is applicable under both acidic and alkaline conditions, has a wider application field, and can be applied to the fields of industrial cleaning, oil fields, textile auxiliaries, etc.; and its preparation process is simple, does not require subsequent purification treatment, no toxic or harmful by-products are generated during the preparation process, is green and safe, and has a high conversion rate (79.2-98.4%). BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 is the infrared spectrum of the product obtained in Example 1;

[0055] Figure 2 It is the infrared spectrum of the product obtained in Example 3. DETAILED DESCRIPTION

[0056] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and through specific implementation methods. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0057] Example 1

[0058] This embodiment provides an amphoteric surfactant (sodium N-decylphenyl dipropionate surfactant), and the preparation steps are as follows:

[0059] In a 1000mL four-necked flask equipped with a condenser, a thermometer and a stirrer, add 100g of 4-decylaniline, 3g of 32% sodium hydroxide aqueous solution and 200g of purified water. Stir and heat up. When the temperature reaches 90°C, slowly add 57g of acrylic acid to the reactor through a feeding funnel, and control the addition time to be about 30min. After the addition is completed, stir and react at 90°C for 12h. After the reaction is completed, cool to 50°C, add 45g of 32% sodium hydroxide aqueous solution dropwise, adjust the pH to 8.0, and obtain the amphoteric surfactant. The conversion rate of the reaction is 97.2%.

[0060] The amphoteric surfactant is characterized as follows Figure 1 As shown. Figure 1 It can be seen that: 2885cm-1 , 2895cm -1 The stretching vibration absorption peaks of CH3- and -CH2- are 3325cm -1 , 1637cm -1 It is the characteristic absorption peak of carboxyl -COO-; 1578cm -1 is the stretching vibration absorption peak of CN; 782cm -1 It is the characteristic peak of benzene ring, indicating the presence of CN bond, -COO-, methylene and benzene ring substituents.

[0061] Example 2

[0062] This embodiment provides an amphoteric surfactant (sodium N-butylphenyl dipropionate surfactant), and the preparation steps are as follows:

[0063] In a 1000mL four-necked flask equipped with a condenser, a thermometer and an agitator, add 100g of 4-butylaniline, 3.2g of a 32% aqueous sodium hydroxide solution and 270g of purified water. Stir and heat up. When the temperature reaches 90°C, slowly add 91.5g of acrylic acid to the reactor through a feeding funnel. The time is controlled to be about 45min. After the addition is completed, stir and react at 95°C for 13.5h. After the reaction is completed, cool to 50°C, add 32g of a 32% aqueous sodium hydroxide solution dropwise, adjust the pH to 8.5, and obtain the amphoteric surfactant. The conversion rate of the reaction is 96.7%.

[0064] Example 3

[0065] This embodiment provides an amphoteric surfactant (sodium N-octylbenzyl dipropionate surfactant), and the preparation steps are as follows:

[0066] In a 1000mL four-necked flask equipped with a condenser, a thermometer and an agitator, add 100g of 4-octylbenzylamine, 4g of a 32% aqueous sodium hydroxide solution and 175g of purified water. Stir and heat up. When the temperature reaches 80°C, slowly add 62.5g of acrylic acid to the reactor through a feeding funnel, and control the addition time to be about 45min. After the addition is completed, stir and react at 90°C for 8.5h. After the reaction is completed, cool to 50°C, add 50g of a 32% aqueous sodium hydroxide solution dropwise, adjust the pH to 9.0, and obtain the amphoteric surfactant. The conversion rate of the reaction is 98.4%.

[0067] The amphoteric surfactant is characterized as follows Figure 2 As shown. Figure 2 It can be seen that: 2886cm -1 , 2896cm -1 The stretching vibration absorption peaks of CH3- and -CH2- are 3327cm -1, 1638cm -1 It is the characteristic absorption peak of carboxyl -COO-; 1578cm -1 is the stretching vibration absorption peak of CN; 782cm -1 It is the characteristic peak of benzene ring, indicating the presence of CN bond, -COO-, methylene and benzene ring substituents.

[0068] Example 4

[0069] This embodiment provides an amphoteric surfactant (N-hexylphenyl dimethyl propionate sodium surfactant), and the preparation steps are as follows:

[0070] In a 1000mL four-necked flask equipped with a condenser, a thermometer and an agitator, add 100g of 4-hexylaniline, 3.9g of a 32% aqueous sodium hydroxide solution and 270g of purified water. Stir and heat up. When the temperature reaches 80°C, slowly add 90g of methacrylic acid to the reactor through a feeding funnel, and control the addition time to be about 60min. After the addition is completed, stir and react at 95°C for 15h. After the reaction is completed, cool to 50°C, add 55g of a 32% aqueous sodium hydroxide solution dropwise, adjust the pH to 8.0, and obtain the amphoteric surfactant. The conversion rate of the reaction is 97%.

[0071] Example 5

[0072] This embodiment provides an amphoteric surfactant (N-tert-butylphenylethyl sodium dipropionate surfactant), and the preparation steps are as follows:

[0073] In a 1000mL four-necked flask equipped with a condenser, a thermometer and an agitator, add 100g of 4-tert-butylphenylethylamine, 1.56g of a 32% aqueous sodium hydroxide solution and 100g of purified water. Stir and heat up. When the temperature reaches 75°C, slowly add 396g of a 24% aqueous sodium acrylate solution to the reactor through a feed funnel, and control the addition time to be about 60min. After the addition is completed, stir and react at 75°C for 5h. After the reaction is completed, cool to 50°C, drop 10g of a 32% aqueous sodium hydroxide solution, adjust the pH to 9.0, and obtain the amphoteric surfactant. The conversion rate of the reaction is 95.4%.

[0074] Example 6

[0075] This embodiment provides an amphoteric surfactant (sodium N-butylnaphthyl dipropionate surfactant), and the preparation steps are as follows:

[0076] In a 1000mL four-necked flask equipped with a condenser, a thermometer and a stirrer, add 100g of 4-butyl-1-naphthylamine, 2g of potassium carbonate and 200g of purified water. Stir and heat up. When the temperature reaches 90°C, slowly add 65g of acrylic acid to the reactor through a feeding funnel, and control the addition time to be 60min. After the addition is completed, stir and react at 100°C for 10h. After the reaction is completed, cool to 50°C, add 75g of 32% potassium hydroxide aqueous solution, adjust the pH to 8.2, and obtain the amphoteric surfactant. The conversion rate of the reaction is 96.4%.

[0077] Example 7

[0078] This embodiment provides an amphoteric surfactant (sodium N-decylphenyl dipropionate surfactant), which is different from Example 1 only in that no 32% sodium hydroxide aqueous solution is added during the reaction, and other raw materials, addition amounts and preparation methods are the same as those in Example 1. The conversion rate of the reaction is 79.2%.

[0079] Example 8

[0080] This embodiment provides an amphoteric surfactant (sodium N-decylphenyl dipropionate surfactant), which is different from Example 1 only in that the amount of 32% sodium hydroxide aqueous solution added is adjusted from 3g to 1.56g, and other raw materials, addition amounts and preparation methods are the same as those in Example 1. The conversion rate of the reaction is 94.6%.

[0081] Example 9

[0082] This embodiment provides an amphoteric surfactant (sodium N-decylphenyl dipropionate surfactant), which is different from Example 1 only in that the amount of 32% sodium hydroxide aqueous solution added is adjusted from 3g to 6.25g, and other raw materials, addition amounts and preparation methods are the same as those in Example 1. The conversion rate of the reaction is 97.3%.

[0083] Example 10

[0084] This embodiment provides an amphoteric surfactant (sodium N-decylphenyl dipropionate surfactant), which is different from Example 1 only in that the amount of 32% sodium hydroxide aqueous solution added is adjusted from 3g to 7.8g, and other raw materials, addition amounts and preparation methods are the same as those in Example 1. The conversion rate of the reaction is 97.1%.

[0085] Embodiment 11

[0086] This embodiment provides an amphoteric surfactant (sodium N-decylphenyl dipropionate surfactant), which is different from Example 1 only in that 57g of acrylic acid is adjusted to 54g of acrylic acid, and other raw materials, addition amounts and preparation methods are the same as those in Example 1. The conversion rate of the reaction is 92.5%.

[0087] Example 12

[0088] This embodiment provides an amphoteric surfactant (sodium N-decylphenyl dipropionate surfactant), which is different from Example 1 only in that 57 g of acrylic acid is adjusted to 55.5 g of acrylic acid, and other raw materials, addition amounts and preparation methods are the same as those in Example 1. The conversion rate of the reaction is 96.4%.

[0089] Embodiment 13

[0090] This embodiment provides an amphoteric surfactant (sodium N-decylphenyl dipropionate surfactant), which is different from Example 1 only in that 57 g of acrylic acid is adjusted to 65 g of acrylic acid, and other raw materials, addition amounts and preparation methods are the same as those in Example 1. The conversion rate of the reaction is 96.0%.

[0091] Embodiment 14

[0092] This embodiment provides an amphoteric surfactant (sodium N-decylphenyl dipropionate surfactant), which is different from Example 1 only in that 57 g of acrylic acid is adjusted to 66.4 g of acrylic acid, and other raw materials, addition amounts and preparation methods are the same as those in Example 1. The conversion rate of the reaction is 94.2%.

[0093] Comparative Example 1

[0094] This comparative example provides an amphoteric surfactant (sodium N-decyl dipropionate surfactant), and its preparation steps are as follows:

[0095] In a 1000mL four-necked flask equipped with a condenser, a thermometer and a stirrer, add 100g of decylamine, 5g of a 32% aqueous sodium hydroxide solution and 260g of purified water. Stir and heat up. When the temperature reaches 90°C, slowly add 70g of acrylic acid to the reactor through a feeding funnel, and control the addition time to be 60min. After the addition is completed, stir and react at 95°C for 15h. After the reaction is completed, cool to 50°C, add 55g of a 32% aqueous sodium hydroxide solution dropwise, adjust the pH to 8.0, and obtain the amphoteric surfactant. The conversion rate of the reaction is 92.0%.

[0096] Comparative Example 2

[0097] This comparative example provides a commercially available nonionic surfactant isomeric tridecanol polyoxyethylene ether (1309) with excellent emulsification, penetration and wetting properties.

[0098] The performance tests were performed on the surfactants obtained in the above Examples 1-6 and Comparative Examples 1-2, and the test methods / standards are as follows:

[0099] (1) Physical and chemical testing

[0100] Surface tension test: GB / T 22237-2008, the mass fraction of surfactant is 1%;

[0101] Foam performance: GB / T 7462-1994, the mass fraction of surfactant is 0.25%;

[0102] Emulsification performance test: Add 40 mL of 0.15% surfactant solution to a 100 mL stoppered measuring cylinder, mix it with 40 mL of liquid paraffin or soybean oil, cover the stopper, let it stand at a constant temperature of 25°C for 1 min, shake it violently up and down 10 times, place it on the table, record the time from standing to the separation of 40 mL of water phase, repeat the measurement three times and take the average value.

[0103] The test results are shown in Table 1.

[0104] Table 1

[0105]

[0106] (2) Solubility test

[0107] 100 g of a 2% surfactant solution was prepared and gradually added to the solubilized organic matter at 25°C, and the maximum amount added that could achieve dissolution was recorded; according to the same method, the solubilization performance of the 2% surfactant solution on organic matter at pH 1.8 (hydrochloric acid adjustment) and pH 12 (sodium hydroxide adjustment) was measured respectively. The test results are shown in Table 2.

[0108] Table 2

[0109]

[0110] (3) Appearance test

[0111] A surfactant solution with a mass fraction of 1% was prepared, and the pH was adjusted to different values ​​using 1M HCl or 1M NaOH solution to observe the appearance. The results are shown in Table 3.

[0112] Table 3

[0113]

[0114] (4) Alkali resistance test

[0115] Sodium hydroxide solutions with different mass fractions of 15%, 20%, 25% and 30% were prepared, and a surfactant with a mass fraction of 1% was added. The test results are shown in Table 4.

[0116] Table 4

[0117]

[0118] The test results show that:

[0119] It can be seen from Examples 1 to 6 in Tables 1-4 that the amphoteric surfactant provided by the present invention has good solubilization while maintaining good surface tension and emulsification properties. Furthermore, the amphoteric surfactant still has a good solubilization effect under strong acidic conditions, and it also has good alkali resistance and is still soluble and transparent under strong alkalinity.

[0120] By comparing Examples 1-6 with Comparative Examples 1 and 2 in Table 2, it can be seen that the amphoteric surfactant provided by the present invention has good solubilization performance. In normal use, its solubilization performance for xylene is 0.92-2.54 g, its solubilization performance for jojoba oil is 0.18-0.34 g, and its solubilization performance for white oil is 0.85-1.57 g, which are much higher than the solubilization performance of the corresponding organic matter in Comparative Examples 1 and 2; at the same time, compared with the surfactant containing only fatty chain amines provided in Comparative Example 1 and the ionic surfactant provided in Comparative Example 2, the surfactant with a specific structure provided by the present invention has better solubilization performance under acidic conditions of pH=1.8 and alkaline conditions of pH=12.0, indicating that the surfactant of the present invention has significant advantages in solubilization effect, thereby greatly expanding its application range.

[0121] It can be seen from Table 4 that Examples 1-6 can all remain dissolved and transparent in sodium hydroxide solutions of different mass concentrations, while the surfactant in Comparative Example 1 is opaque in a sodium hydroxide solution of a higher mass concentration (30%), and Comparative Example 2 is opaque in a sodium hydroxide solution of a low mass concentration (5%), and all become turbid in a sodium hydroxide solution of a mass fraction of 15-30%, further indicating that the amphoteric surfactant provided by the present invention has good alkali resistance.

[0122] In summary, the present invention adopts aromatic organic amine and acrylic compound as raw materials, and prepares amphoteric surfactant with high conversion rate under specific catalysis. The amphoteric surfactant with specific structure has good solubilizing performance and excellent comprehensive performance.

[0123] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. An amphoteric surfactant, characterized in that The amphoteric surfactant has a structure shown in formula (I): In formula (I), Ar is selected from phenyl or naphthyl; R is selected from a C4-C12 straight chain or branched alkyl group; R1 is selected from H or methyl; m is an integer of 0-2; M is Na or K.

2. A method for preparing the amphoteric surfactant according to claim 1, characterized in that: The preparation method comprises the following steps: The amphoteric surfactant is obtained by reacting an aromatic organic amine compound with an acrylic compound.

3. The method for preparing the amphoteric surfactant according to claim 2, characterized in that: The aromatic-containing organic amine compound has a structure described by formula (II): In formula (II), Ar is selected from phenyl or naphthyl, R is selected from C4-C12 straight chain or branched alkyl, and m is an integer of 0-2.

4. The method for preparing the amphoteric surfactant according to claim 2 or 3, characterized in that: The acrylic compound is acrylic acid or methacrylic acid.

5. The method for preparing the amphoteric surfactant according to any one of claims 2 to 4, characterized in that: The molar ratio of the aromatic-containing organic amine compound to the acrylic compound is 1:(1.8-2.10).

6. The method for preparing the amphoteric surfactant according to any one of claims 2 to 5, characterized in that: The reaction is carried out in a solvent; Preferably, the solvent is a protic solvent; Preferably, the protic solvent comprises water; Preferably, the water includes any one of tap water, distilled water, purified water or deionized water, or a combination of at least two of them.

7. The method for preparing an amphoteric surfactant according to any one of claims 2 to 6, characterized in that: The reaction is carried out under the catalysis of a catalyst; Preferably, the catalyst comprises any one or a combination of at least two of NaOH, KOH, Na2CO3 or K2CO3; Preferably, the added amount of the catalyst is 0.5-2% of the mass of the aromatic-containing organic amine compound.

8. The method for preparing the amphoteric surfactant according to any one of claims 2 to 7, characterized in that: The reaction temperature is 75-100°C; Preferably, the reaction time is 5-15h; Preferably, after the reaction is completed, the pH is adjusted to 8.0-9.0; Preferably, the pH is adjusted using a base; Preferably, the base comprises NaOH and / or KOH.

9. The method for preparing the amphoteric surfactant according to any one of claims 2 to 8, characterized in that: The preparation method specifically comprises the following steps: The aromatic organic amine compound, the catalyst and the solvent are mixed, the temperature is raised to 75-100° C. under stirring, and the acrylic compound is added. After the addition is completed, the reaction is carried out at 75-100° C. for 5-15 hours. After the reaction is completed, the pH is adjusted to 8.0-9.0 with a base to obtain the amphoteric surfactant; The molar ratio of the aromatic-containing organic amine compound to the acrylic compound is 1:(1.8-2.10); The added amount of the catalyst is 0.5-2% of the mass of the aromatic-containing organic amine compound.

10. Use of the amphoteric surfactant according to claim 1 in industrial cleaning, lubricants, environmental management or personal care.

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