Fatty alcohol ether carboxylic acid and preparation method thereof

Abstract

The invention relates to the technical field of surfactant synthesis, in particular to fatty alcohol ether carboxylic acid and a preparation method thereof. The method comprises the following steps: in an anhydrous environment, adding fatty alcohol ether and solid alkali into mechanical mixing equipment, and carrying out alkalization reaction to obtain a mixture; adding chloroacetate into the mixture, and carrying out carboxymethylation reaction to obtain fatty alcohol ether carboxylic acid; wherein the rotating speed of the mechanical mixing equipment is 400 to 700 rpm (revolutions per minute). According to the method, high-efficiency synthesis of fatty alcohol ether carboxylic acid is realized under mild and solvent-free conditions by using the solid base catalyst, and requirements of green chemistry and low-carbon chemical industry are better met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of surfactant synthesis, and particularly relates to a fatty alcohol ether carboxylic acid and a preparation method thereof. BACKGROUND

[0002] Alcohol ether carboxylic acid (AEC-H) and its carboxylic acid salt are a kind of surfactant with excellent performance, which are widely used in the fields of textile industry, cosmetics and the like. The alcohol ether carboxylic acid has excellent wetting and foaming performance, and can also be used as a heavy oil viscosity reducer in the field of petroleum chemical industry. In recent years, with the continuous enhancement of public health and environmental protection awareness, higher requirements are put forward for the mildness and safety of product formula, and the environmentally friendly surfactant such as alcohol ether carboxylic acid has attracted widespread attention of researchers.

[0003] There are various synthesis methods for alcohol ether carboxylic acid, including carboxymethylation, oxidation, conjugate addition, acid anhydride esterification and the like. Among them, the carboxymethylation method has been widely used in industrial production. The carboxymethylation method usually uses chloroacetic acid and its salt as a carboxymethylation reagent, and the reaction is carried out in a reaction kettle under certain temperature and alkaline conditions. The reaction principle is that the raw material fatty alcohol ether reacts with alkali to generate sodium alcoholate, and then the sodium alcoholate reacts with the carboxymethylation reagent chloroacetate to generate fatty alcohol ether carboxylate salt, and finally the product is obtained through acidification and purification. However, due to the poor compatibility between different reaction materials, the reaction time of the synthesis process by the carboxymethylation method is very long, usually 3-8 hours, and the long reaction time and the introduction of solvent increase the possibility of hydrolysis of the carboxymethylation reagent, thereby reducing its utilization rate. Therefore, researchers currently focus on how to improve the synthesis efficiency of fatty alcohol ether carboxylic acid.

[0004] Patents with publication numbers CN118978435A and CN115583881B both use the carboxymethylation method to synthesize alcohol ether carboxylic acid product, and improve the reaction efficiency by replacing the organic alkali source and adding solvent, but the production cost is significantly increased, and the system viscosity is high in the later stage of the reaction, so the reaction is difficult to complete fully. Patents with publication numbers CN115894208B and CN114890891A use catalytic oxidation method to synthesize alcohol ether carboxylic acid salt, which avoids the use of carboxylation reagent and has good atom economy, but the cost of the catalyst is high, the process flow is complex, and there is a problem of catalyst recovery, which limits the actual application. Therefore, it is still an urgent and challenging task to develop a green and efficient synthesis technology for fatty alcohol ether carboxylic acid. SUMMARY

[0005] The present application aims to at least partially solve one of the technical problems in the related art. To this end, the present application provides a fatty alcohol ether carboxylic acid and a preparation method thereof. The method uses a solid alkali catalyst to realize efficient synthesis of fatty alcohol ether carboxylic acid under mild and solvent-free conditions, which is more in line with the requirements of green chemistry and low-carbon chemical industry.

[0006] To this end, the present application provides a method for preparing fatty alcohol ether carboxylic acid based on mechanochemistry, comprising the following steps:

[0007] In anhydrous environment, a fatty alcohol ether and a solid base are added into a mechanical mixing device to perform a basification reaction, and a mixture is obtained;

[0008] A chloroacetate is added into the mixture to perform a carboxymethylation reaction, and a fatty alcohol ether carboxylic acid is obtained.

[0009] The rotation speed of the mechanical mixing device is 400 rpm-700 rpm.

[0010] The method provided by the present application can be performed under normal temperature and pressure, has a short reaction time, and does not require the addition of a solvent, thereby solving the problems of low reaction efficiency, viscosity limitation of the system, and cost and product quality affected by the introduction of a solvent existing in the prior art.

[0011] According to an embodiment of the present application, the molecular formula of the fatty alcohol ether is RO-[CH2CH2O] n -CH2OH; wherein R is selected from any one of C2-C 14 alkyl; and n is 1-20.

[0012] According to an embodiment of the present application, the mass ratio of the fatty alcohol ether to the solid base is (3-15):1. In this way, the raw materials can be fully subjected to the basification reaction, and the utilization rate of the solid base is improved.

[0013] According to an embodiment of the present application, the solid base comprises at least one of calcium oxide, calcium hydroxide, and sodium hydroxide. In this way, the method provided by the present application expands the selection range of the base, allowing the use of difficultly soluble solid bases such as calcium oxide and calcium hydroxide, thereby further reducing the cost or reducing the amount of by-products.

[0014] According to an embodiment of the present application, the basification reaction is performed for 30 min-180 min. In this way, the basification reaction can be fully performed.

[0015] According to an embodiment of the present application, the mechanical mixing device comprises at least one of a ball mill, a sand mill, and a double-screw extruder.

[0016] According to an embodiment of the present application, the mass ratio of the chloroacetate to the fatty alcohol ether is (1.5-4):1. In this way, the raw materials can be fully subjected to the carboxymethylation reaction, and the utilization rate of the chloroacetate is improved.

[0017] According to an embodiment of the present application, the chloroacetate comprises at least one of sodium chloroacetate and potassium chloroacetate.

[0018] According to the embodiment of the present application, the carboxymethylation reaction is performed for 20-80 minutes. Thus, the present application provides a method for performing carboxymethylation reaction in a significantly shorter time than the prior art, thereby improving the reaction efficiency and reducing the probability of side reactions.

[0019] According to the embodiment of the present application, the carboxymethylation reaction is further followed by subjecting the reaction product to acidification treatment and purification treatment to obtain a fatty alcohol ether carboxylic acid.

[0020] The second aspect of the present application provides a fatty alcohol ether carboxylic acid prepared by the method according to the first aspect, wherein the fatty alcohol ether carboxylic acid has a molecular formula of RO-[CH2CH2O] n -CH2-O-CH2COOH; wherein R is selected from any one of C2-C 14 alkyl groups; and n is 1-20.

[0021] The present application has the following advantages over the prior art:

[0022] (1) The mechanical-chemical synthesis method without solvent solves the problem that different reactants cannot effectively contact due to poor compatibility, and avoids the influence of impurities introduced by solvent and the cost of separation and recovery.

[0023] (2) The selection range of base is expanded, allowing the use of calcium oxide, calcium hydroxide and other insoluble solid bases, thereby further reducing the cost or reducing the amount of by-products.

[0024] (3) The solid-liquid and solid-solid contact is effectively enhanced by mechanical force, and the carboxymethylation reaction can be efficiently completed under mild conditions, thereby improving the production efficiency and saving energy.

[0025] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0026] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the accompanying drawings, wherein:

[0027] Figure 1 The infrared spectrum of the fatty alcohol ether carboxylic acid prepared in Examples 1-3 of the present application is shown. DETAILED DESCRIPTION

[0028] The embodiments of the present application are described in detail below. The embodiments described below are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0029] It should be noted that the terms "first", "second", etc. are used only for descriptive purposes and are not to be construed as implying or implying a relative importance or an indication of the number of the technical features indicated. Thus, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. Further, in the description of the present application, unless otherwise stated, the meaning of "a plurality" is two or more.

[0030] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The ranges or values should be construed to be approximations which can vary depending on the intended application. For numerical ranges, the end points are included with the ranges, the end points are included with the ranges, and individual points are included with the ranges. These ranges are to be construed as having been specifically disclosed.

[0031] In order to facilitate the understanding of the present application, certain technical and scientific terms are specifically defined below. Unless otherwise apparent from the context, all other technical and scientific terms used herein have the meanings commonly understood by one of ordinary skill in the art to which the present application belongs.

[0032] In this document, the terms "comprising" or "including" are open-ended terms, i.e. they include the indicated content but not excluding other aspects.

[0033] In this document, the term "optionally", "optional" or "optional" generally means that the event or condition described thereafter can but does not necessarily occur, and the description includes both cases where the event or condition occurs and cases where it does not occur.

[0034] Definitions and explanations of terms

[0035] Unless otherwise stated, the group and term definitions set forth in the specification and claims of the present application, including the definitions of examples, exemplary definitions, preferred definitions, definitions set forth in tables, definitions of specific compounds in examples, etc. can be combined and combined with each other. The group definition and compound structure after such combination should belong to the range disclosed in the specification of the present application.

[0036] The term "C2-C 14"Alkyl" is understood to mean a linear or branched saturated monovalent hydrocarbon group having 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 carbon atoms. Said alkyl group is, for example, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl or 1,2-dimethylbutyl, etc.

[0037] According to an embodiment of the present application, the first aspect of the present application provides a method for preparing fatty alcohol ether carboxylic acid based on mechanochemistry, the method comprising the following steps:

[0038] (1) adding fatty alcohol ether and solid base in a mechanical mixing device under water-free environment to perform alkalization reaction, and obtaining a mixture;

[0039] The rotation speed of the mechanical mixing device is 400 rpm-700 rpm.

[0040] The method provided by the present application uses a mechanical mixing device to provide mechanical force to promote intermolecular interaction and initiate chemical reaction. The mechanical force can break the original bond between molecules to generate active sites, thereby realizing chemical conversion under solvent-free conditions. In addition, the inventors found that controlling the rotation speed of the mechanical mixing device to be 400 rpm-700 rpm can make the reaction have good rate and conversion rate. If the rotation speed of the device is too low, the mixing effect of the raw materials is limited, and the alkalization reaction and carboxymethylation reaction cannot be fully performed, which affects the carboxylation degree of the product. If the rotation speed of the device is too high, the local thermal effect is more significant due to the enhanced mechanical friction, which increases the possibility of side reactions. In addition, the high rotation speed condition requires higher mechanical strength of the device, and long-time high rotation speed reaction can accelerate the wear of the device and affect the service life of the device.

[0041] According to a specific embodiment of the present application, the molecular formula of the fatty alcohol ether is RO-[CH2CH2O] n -CH2OH; wherein R is selected from any one of C2-C 14 alkyl; and n is 1-20.

[0042] According to a specific embodiment of the present application, the mass ratio of the fatty alcohol ether to the solid base is (3-15):1. As some specific examples, the mass ratio of the fatty alcohol ether to the solid base can be 3:1, 5:1, 10:1, 15:1, etc. In this way, the raw materials can be fully alkalized and the utilization rate of the solid base can be improved.

[0043] According to a specific embodiment of the present application, the kind of the solid base is not particularly limited, and as some specific examples, the solid base comprises at least one of calcium oxide, calcium hydroxide, sodium hydroxide. Thus, the method provided by the present application expands the selection range of the base, allowing the use of calcium oxide, calcium hydroxide and other insoluble solid bases, thereby further reducing the cost or reducing the amount of by-products.

[0044] According to a specific embodiment of the present application, the time of the alkalization reaction is 30 min-180 min, and as some specific examples, the time of the alkalization reaction can be 30 min, 50 min, 100 min, 150 min, 180 min, etc. Thus, the alkalization reaction can be carried out sufficiently.

[0045] According to a specific embodiment of the present application, the kind of the mechanical mixing device is not particularly limited, and as some specific examples, the mechanical mixing device comprises at least one of a ball mill, a sand mill, a twin-screw extruder. Specifically, when a ball mill or a sand mill is used, a grinding medium can be added, and the kind of the grinding medium is not particularly limited, for example, zirconium oxide balls can be used. The ball-to-material ratio of the zirconium oxide balls can be not particularly limited, for example, the ball-to-material ratio can be 5:1.

[0046] According to a specific embodiment of the present application, the reaction conditions of the alkalization reaction are not particularly limited, for example, it can be carried out at normal temperature and pressure.

[0047] Specifically, when calcium oxide is used as the solid base, the reaction equation of step (1) is as follows:

[0048] 2RO-[CH2CH2O] n -CH2OH+CaO→(RO-[CH2CH2O] n -CH2O)2Ca+H2O

[0049] (2) adding chloroacetate in the mixture to carry out carboxymethylation reaction to obtain fatty alcohol ether carboxylic acid.

[0050] According to a specific embodiment of the present application, the mass ratio of the chloroacetate and the fatty alcohol ether is (1.5-4):1, and as some specific examples, the mass ratio of the chloroacetate and the fatty alcohol ether can be 1.5:1, 2:1, 3:1, 4:1, etc. Thus, it can ensure that the raw materials are fully carboxymethylated and improve the utilization rate of chloroacetate.

[0051] According to a specific embodiment of the present application, the kind of the chloroacetate is not particularly limited, and as some specific examples, the chloroacetate comprises at least one of sodium chloroacetate, potassium chloroacetate.

[0052] According to a specific embodiment of the present application, the carboxymethylation reaction is performed for 20-80 minutes. As some specific examples, the carboxymethylation reaction can be performed for 20 minutes, 40 minutes, 60 minutes, 80 minutes, etc. Thus, the present application provides a method in which the time for the carboxymethylation reaction is significantly shorter than the reaction time in the prior art, thereby improving the reaction efficiency and reducing the probability of occurrence of side reactions.

[0053] According to a specific embodiment of the present application, the carboxymethylation reaction is further followed by subjecting the reaction product to acidification treatment and purification treatment to obtain a fatty alcohol ether carboxylic acid.

[0054] Specifically, when sodium chloroacetate is used as the chloroacetate salt, the reaction equation of step (2) is as follows:

[0055] (RO-[CH2CH2O] n -CH2O)2Ca+2ClCH2COONa→(RO-[CH2CH2O] n -CH2O-CH2COO)2Ca+2NaCl

[0056] According to an embodiment of the present application, the second aspect of the present application provides a fatty alcohol ether carboxylic acid prepared by the method according to the first aspect, the fatty alcohol ether carboxylic acid having a molecular formula of RO-[CH2CH2O] n -CH2-O-CH2COOH; wherein R is selected from any one of C2-C 14 alkyl groups; and n is 1-20.

[0057] The schemes of the present application will be explained below in conjunction with the examples. Those skilled in the art will understand that the following examples are only used to illustrate the present application and should not be regarded as limiting the scope of the present application. In the examples, the specific techniques or conditions not mentioned are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. The reagents or instruments not mentioned are all conventional products that can be commercially available.

[0058] Example 1

[0059] The present example provides a fatty alcohol ether carboxylic acid and a preparation method thereof, the preparation method comprising the following steps:

[0060] A raw material fatty alcohol ether having a chemical formula of C 12 H 25O(CH2CH2O)9H) and solid calcium oxide, along with zirconium oxide beads at a ball-to-material ratio of 1:5, were used. A sealed ball mill jar containing the sample was placed in an anhydrous environment, and the milling speed was set to 600 rpm for 1 hour. The intermediate product was then treated with sodium chloroacetate (sodium chloroacetate to fatty alcohol ether feed ratio of 3:1) in an anhydrous environment, sealed, and ball-milled again under the same conditions for 30 minutes. The crude product was then purified by acidification and solvent extraction to obtain fatty alcohol ether carboxylic acid.

[0061] The infrared spectrum of the fatty alcohol ether carboxylic acid prepared in this embodiment is as follows: Figure 1 As shown.

[0062] Example 2

[0063] The only difference between this embodiment and Embodiment 1 is that the solid alkali used is replaced with sodium hydroxide instead of calcium oxide.

[0064] The infrared spectrum of the fatty alcohol ether carboxylic acid prepared in this embodiment is as follows: Figure 1 As shown.

[0065] Example 3

[0066] The only difference between this embodiment and Example 1 is that the solid alkali used is replaced with calcium hydroxide instead of calcium oxide.

[0067] The infrared spectrum of the fatty alcohol ether carboxylic acid prepared in this embodiment is as follows: Figure 1 As shown.

[0068] Example 4

[0069] This embodiment provides a fatty alcohol ether carboxylic acid and its preparation method, the preparation method comprising the following steps:

[0070] In an anhydrous environment, a raw material fatty alcohol ether (with the chemical formula C) was prepared at a mass ratio of 13:1. 12 H 25 The prepared sample was prepared with O(CH2CH2O)9H, solid calcium oxide, and zirconia beads with a ball-to-material ratio of 1:5. The sample was then subjected to a fine grinding process in a sand mill at 600 rpm for 1 hour. The intermediate product was then treated with sodium chloroacetate (sodium chloroacetate to fatty alcohol ether mass ratio of 3:1) in an anhydrous environment, sealed, and milled again under the same conditions for 30 minutes. The crude product was then purified by acidification and solvent extraction to obtain fatty alcohol ether carboxylic acid.

[0071] Example 5

[0072] This embodiment provides a fatty alcohol ether carboxylic acid and its preparation method, the preparation method comprising the following steps:

[0073] The raw material fatty alcohol ether (chemical formula: C 12 H 25 O(CH2CH2O)9H) and solid base calcium oxide suspension. The prepared sample was placed into a twin-screw extruder, the rotation speed was set to 600 rpm, and the alkalization reaction time was 1 h. The intermediate product after reaction was added with sodium chloroacetate (the mass ratio of sodium chloroacetate to fatty alcohol ether was 3:1) in a water-free environment, uniformly mixed, and sheared and mixed for 30 min by a twin-screw extruder under the same conditions. The crude product after reaction was subjected to acidification and solvent purification to obtain a fatty alcohol ether carboxylic acid.

[0074] Example 6

[0075] The present example provides a fatty alcohol ether carboxylic acid and a preparation method thereof, the preparation method comprising the following steps:

[0076] The raw material fatty alcohol ether (chemical formula: C 12 H 25 O(CH2CH2O)7H) and solid base calcium oxide and zirconium oxide beads with a ball-to-material ratio of 1:5. A ball mill tank was sealed in a water-free environment, and the sample-filled ball mill tank was placed into a ball mill, the rotation speed was set to 400 rpm, and the alkalization reaction time was 180 min. The intermediate product after reaction was added with sodium chloroacetate (the mass ratio of sodium chloroacetate to fatty alcohol ether was 1.5:1) in a water-free environment, and was sealed and subjected to ball milling reaction for 20 min under the same conditions. The crude product after reaction was subjected to acidification and solvent purification to obtain a fatty alcohol ether carboxylic acid.

[0077] Example 7

[0078] The present example provides a fatty alcohol ether carboxylic acid and a preparation method thereof, the preparation method comprising the following steps:

[0079] The raw material fatty alcohol ether (chemical formula: C 12 H 25 O(CH2CH2O) 12 H) and solid base calcium oxide and zirconium oxide beads with a ball-to-material ratio of 1:5. A ball mill tank was sealed in a water-free environment, and the sample-filled ball mill tank was placed into a ball mill, the rotation speed was set to 700 rpm, and the alkalization reaction time was 30 min. The intermediate product after reaction was added with sodium chloroacetate (the mass ratio of sodium chloroacetate to fatty alcohol ether was 4:1) in a water-free environment, and was sealed and subjected to ball milling reaction for 80 min under the same conditions. The crude product after reaction was subjected to acidification and solvent purification to obtain a fatty alcohol ether carboxylic acid.

[0080] Comparative Example 1

[0081] The difference between this comparative example and Example 1 is that the rotation speed of the ball mill is set to 300 rpm.

[0082] Comparative Example 2

[0083] The difference between this comparative example and Example 1 is that the rotation speed of the ball mill is set to 900 rpm.

[0084] Test Example

[0085] The fatty alcohol ether carboxylic acids prepared in the above examples and comparative examples were tested as follows:

[0086] (1) Carboxylation degree test

[0087] The carboxylation degree of the fatty alcohol ether carboxylic acid product was calculated from the volume of alkali consumed in acid-base neutralization titration, using a sodium hydroxide standard solution as the titrant and phenolphthalein as the indicator. The specific operation was as follows: the mass of the sample was accurately weighed, a certain amount of anhydrous ethanol was added for dissolution, a few drops of 0.1% phenolphthalein were added as the indicator, and the sodium hydroxide standard solution was titrated until the system changed from colorless to pink, and the amount V NaOH (mL) of sodium hydroxide titration consumed was recorded. The carboxylation degree a was calculated according to the following formula:

[0088]

[0089] Wherein, the meanings of the symbols are as follows:

[0090] C: concentration of the sodium hydroxide standard solution (mol / L);

[0091] M sample : molecular weight of the sample;

[0092] V NaOH : titration consumption (mL);

[0093] W: sample weight (g).

[0094] (2) pH value test

[0095] According to GB / T 6368, a 10% aqueous solution was prepared, maintained at 25°C, and read after the pH meter was stabilized under stirring. The absolute difference between two independent test results obtained under repeatability conditions should not be greater than 0.1.

[0096] The properties of the fatty alcohol ether carboxylic acids prepared in Examples 1-7 and Comparative Examples 1-2 are shown in Table 1.

[0097] Table 1

[0098] Sample Product appearance pH Carboxylation degree Example 1 pale yellow viscous liquid 2-3 93.7％ Example 2 pale yellow viscous liquid 2-3 90.2％ Example 3 pale yellow viscous liquid 2-3 89.5％ Example 4 pale yellow viscous liquid 2-3 94.1％ Example 5 yellow viscous liquid 2-3 88.1％ Example 6 pale yellow viscous liquid 2-3 91.5％ Example 7 pale yellow viscous liquid 2-3 92.8％ Comparative Example 1 pale yellow viscous liquid 2-3 72.9％ Comparative Example 2 pale yellow viscous liquid 2-3 87.4％

[0099] Result analysis: According to Table 1 and Figure 1The results show that the method successfully prepares the fatty alcohol ether carboxylic acid, and the reaction has high conversion rate.

[0100] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. Furthermore, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0101] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and the person skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. A process for the mechanochemical preparation of fatty alcohol ether carboxylic acids, characterized in that, The method comprises the following steps: In anhydrous environment, adding fatty alcohol ether and solid base in a mechanical mixing device to carry out alkalization reaction to obtain a mixture; Adding chloroacetate in the mixture to carry out carboxymethylation reaction to obtain fatty alcohol ether carboxylic acid; The rotation speed of the mechanical mixing device is 400 rpm-700 rpm.

2. The method of claim 1, wherein, The molecular formula of the fatty alcohol ether is RO-[CH2CH2O] n -CH2OH; wherein R is selected from any one of C2-C 14 alkyl; n is 1-20.

3. The method of claim 1, wherein, The mass ratio of the fatty alcohol ether to the solid base is (3-15):

1.

4. The method of claim 1, wherein, The solid base comprises at least one of calcium oxide, calcium hydroxide and sodium hydroxide.

5. The method of claim 1, wherein, The alkalization reaction time is 30 min-180 min.

6. The method according to any one of claims 1 to 5, characterized in that, The mechanical mixing device comprises at least one of a ball mill, a sand mill and a double screw extruder.

7. The method according to any one of claims 1 to 5, characterized in that, The mass ratio of the chloroacetate to the fatty alcohol ether is (1.5-4):

1. Optionally, the chloroacetate comprises at least one of sodium chloroacetate and potassium chloroacetate.

8. The method according to any one of claims 1 to 5, characterized in that, The carboxymethylation reaction time is 20 min-80 min.

9. The method according to any one of claims 1 to 5, characterized in that, The carboxymethylation reaction further comprises: subjecting the reactants to acidification treatment and purification treatment to obtain fatty alcohol ether carboxylic acid.

10. A fatty alcohol ether carboxylic acid prepared according to the method of any one of claims 1-9, characterized in that, The molecular formula of the fatty alcohol ether carboxylic acid is RO-[CH2CH2O] n -CH2-O-CH2COOH; wherein R is selected from C2-C 14 any one of the alkyl groups; n is 1-20.

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