CN112473551A

CN112473551A - Surfactant and preparation method thereof

Info

Publication number: CN112473551A
Application number: CN202011393102.6A
Authority: CN
Inventors: 蒋小芳
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-12-03
Filing date: 2020-12-03
Publication date: 2021-03-12

Abstract

A surfactant has a structure of

Dissolving alkyl di (aminoethyl) glycine in acetone, continuously dropwise adding formic acid at the speed of 0.5-2 g/min, heating to reflux after dropwise adding, reacting for 3-5 h, performing reflux reaction with glyoxylic acid in the formic acid environment, adjusting the pH value of the system to 10-12, removing the water phase in the system, adding sodium bicarbonate into the acetone phase for washing, filtering, dropwise adding deionized water into the filtrate until crystals are not separated out, collecting the crystalsDrying; the modified alkyl di (aminoethyl) glycine has a special cyclic structure and two amino acid structures, so that the antibacterial performance of the modified alkyl di (aminoethyl) glycine is enhanced, the water solubility of the modified alkyl di (aminoethyl) glycine is enhanced due to the existence of two carboxyl groups in the cyclic structure, the stability of the modified alkyl di (aminoethyl) glycine is excellent, the biodegradability of the modified alkyl di (aminoethyl) glycine is improved, and the hardness of water is effectively reduced.

Description

Surfactant and preparation method thereof

Technical Field

The invention relates to the technical field of surfactants, in particular to a surfactant and a preparation method thereof.

Background

Hard Water (Hard Water) is Water containing a large amount of soluble calcium and magnesium compounds. In the field of daily chemicals, hard water has many negative effects on the skin: when hard water is used for washing face and bathing, mineral substances in the hard water are remained on the skin and permeate a moisturizing layer and natural grease of the skin, so that the skin is dried, pores are blocked, acne, comedo and the like are formed, impurities in the hard water can generate free radicals, collagen in the skin is decomposed, and the skin is aged. The mineral content in the hard water is high, so that the cleansing facial cleanser, the shampoo, the bath lotion and the like for cleansing are not easy to bubble, the cleansing effect is not ideal, and the washing products can remain on the skin to stimulate the skin to cause the problems of eczema, psoriasis and the like.

The surfactant is the most important component in most daily chemical products, and the safety of biodegradation and the irritation to the skin are directly related to the using performance of the product. N-acylamino acids and their salts are the main raw materials for various shampoos and many cosmetics because they are mild to the skin and hair, have very high affinity and moisturizing effect, and produce rich and stable foam.

The alkyl di (aminoethyl) glycine is a light yellow liquid, belongs to an amphoteric surfactant, and is obtained by the sequential reaction of diethylenetriamine, chloroethane and chloroacetic acid. Is a commonly used surfactant having antibacterial, antiseptic, standing, dispersing, emulsifying, and compatibilizing properties. However, alkylbis (aminoethyl) glycine has no outstanding bactericidal and antibacterial properties and is not very biodegradable.

Disclosure of Invention

The invention aims to provide a surfactant which has excellent sterilization and bacteriostasis capabilities, can obviously reduce the hardness of water, and has excellent water solubility and stability.

The invention aims to provide a preparation method of the surfactant.

The purpose of the invention is realized by the following technical scheme:

a surfactant characterized by: the structure of the surfactant is as follows:

the surfactant in the invention is formed by modifying alkyl di (aminoethyl) glycine, and the structure of the alkyl di (aminoethyl) glycine before modification is

After modification, the original chain of the alkyl di (aminoethyl) glycine is transformed into a ring structure, 3 nitrogen atoms are changed into a ring from the original chain, lone electron pairs existing on the nitrogen atoms are aggregated, a large amount of negative charges are aggregated, an electron cloud is formed, the complexing capability of the structure is increased, calcium ions, magnesium ions and the like in water are effectively complexed, and therefore the hardness of the water is reduced. The electron cloud formed by aggregation in the annular structure has enhanced and highly aggregated positive charge adsorption capacity, so that the cell wall of the microorganism is torn by physical tension generated by uneven distribution of biological positive charges, the cell membrane of the microorganism is effectively damaged by the adsorbed positive charges, and the protein in the cell is denatured, thereby improving the bacteriostatic and bactericidal effects of the microorganism. In addition, an amino acid unit is additionally arranged on the cyclic structure, and the hydrophilicity of the cyclic structure is increased due to the increase of carboxyl, so that the water solubility of the modified alkyl di (aminoethyl) glycine is enhanced, the adsorption and diffusion of the modified alkyl di (aminoethyl) glycine on a cell interface are enhanced, the electron cloud is promoted to be efficiently and uniformly diffused on the cell interface, the electron cloud is promoted to effectively adsorb positive charges in a microenvironment, and the modified alkyl di (aminoethyl) glycine has excellent antibacterial performance at a lower concentration. And because of the enhancement of water solubility, the stability of the emulsion is effectively increased when the emulsion is prepared.

The preparation method of the surfactant is characterized by comprising the following steps: taking alkyl di (aminoethyl) glycine as a raw material, taking acetone as a solvent, firstly reacting the alkyl di (aminoethyl) glycine with formic acid to obtain a cyclic intermediate, then carrying out reflux reaction on the cyclic intermediate and glyoxylic acid in the formic acid environment, then adjusting the pH value of the system to 10-12, removing a water phase in the system, adding sodium bicarbonate into the acetone phase for washing, filtering, dropwise adding deionized water into the filtrate until crystals are not separated out, and collecting and drying the crystals; the reaction with formic acid is to dissolve alkyl di (aminoethyl) glycine in acetone, to heat to 35-40 ℃, to continuously drop formic acid, to control the dropping speed at 0.5-2 g/min, to heat to reflux after the dropping is finished, and to react for 3-5 h.

If the reaction process of the alkyl di (aminoethyl) glycine and formic acid is not well controlled, the formic acid directly reacts with one of the amino groups, maintains the linear structure thereof, and cannot be prepared into a cyclic structure consisting of 3 nitrogens and 5 carbons. In the alkyl di (aminoethyl) glycine adopted by the invention, an alkyl chain is C12-14, in the reaction process of the alkyl di (aminoethyl) glycine and formic acid, through the dropwise addition control of the formic acid at the temperature, hydroxyl in the formic acid is separated and is combined with hydrogen on one amino group in the alkyl di (aminoethyl) glycine to form water, at the moment, a nitrogen atom with a lone electron pair is combined with carbon which loses the hydroxyl group and has an empty orbit to form a carbon-nitrogen bond, hydrogen on the other amino group is separated, the carbon-oxygen bond on the formic acid is broken and is combined with the amino group to form the carbon-nitrogen bond, and finally, an intermediate with a cyclic structure is formed. After a cyclic structure is formed, electron cloud is formed, so that hydrogen on a secondary amino group on the cyclic structure is difficult to be separated and difficult to react with glyoxylic acid.

Further, the mass ratio of the alkyl di (aminoethyl) glycine to the acetone is 1-2: 2-3.5.

Further, the molar ratio of the alkyl di (aminoethyl) glycine to the formic acid is 1 to 2:3.5 to 5.

Further, after the reaction with formic acid is finished, a 50% glyoxylic acid aqueous solution is directly added, reflux reaction is carried out for 5-8 hours, and the molar ratio of alkyl di (aminoethyl) glycine to glyoxylic acid is 1: 1.

And further, after the reaction is finished, adding sodium hydroxide or sodium bicarbonate to adjust the pH value of the system to 10-12 until the system is layered, wherein the upper layer is an acetone phase, the lower layer is a water phase, removing the water phase, adding 10-20% by mass of sodium bicarbonate into the acetone phase, washing, adding activated carbon, adsorbing and filtering.

And further, dropwise adding deionized water into the filtrate at a dropwise adding speed of 1-3 g/min, continuously precipitating crystals in the dropwise adding process, and after the crystals are precipitated, controlling the temperature of the solution at 15-20 ℃ for crystal growth for 1-3 hours.

After the water phase is removed by layering, sodium bicarbonate is added into the acetone phase, and activated carbon is added, so that the effect of removing unreacted formic acid, glyoxylic acid and other impurities is achieved. And deionized water is dripped for crystal absorption, the modified alkyl di (aminoethyl) glycine is separated out, and the dripping speed is regulated, so that impurities remained in the filtrate are removed from the crystal body, and the impurities are removed again, thereby improving the purity of the crystal.

Further, filtering, collecting crystals, and drying at 50-60 ℃ under the pressure of-90 KPa.

Most specifically, the preparation method of the surfactant is characterized by comprising the following steps of:

(1) dissolving alkyl di (aminoethyl) glycine in acetone to form a solution, continuously dropwise adding formic acid, controlling the dropwise adding speed to be 0.5-2 g/min, heating to reflux after dropwise adding is finished, reacting for 3-5 h to form a ring-shaped structure intermediate, wherein the molar ratio of the alkyl di (aminoethyl) glycine to the formic acid is 1-2: 3.5-5;

(2) directly adding a 50% glyoxylic acid aqueous solution after the reaction in the step (1), and carrying out reflux reaction for 5-8 h, wherein the molar ratio of alkyl di (aminoethyl) glycine to glyoxylic acid is 1: 1;

(3) after the reaction in the step (2) is finished, adding sodium hydroxide or sodium bicarbonate to adjust the pH value of the reaction system to 10-12 until the system is layered, wherein the upper layer is an acetone phase, the lower layer is a water phase, removing the water phase, adding 10-20% of sodium bicarbonate in mass concentration into the acetone phase, washing, adding activated carbon, adsorbing and filtering;

(4) and dropwise adding deionized water into the filtrate at the dropping speed of 1-3 g/min, continuously precipitating crystals in the dropwise adding process, controlling the temperature of the solution at 15-20 ℃ for crystal growth for 1-3 h after the crystals are precipitated, filtering, collecting the crystals, and drying at the temperature of 50-60 ℃ and below-90 KPa.

The invention has the following technical effects:

the modified alkyl di (aminoethyl) glycine has a special annular structure, forms an electron cloud, has excellent antibacterial property, generates two amino acid units in the annular structure, enhances the antibacterial property of the cyclized alkyl di (aminoethyl) glycine, and has the antibacterial rate of staphylococcus aureus improved from 28.1% to 82.9% and the antibacterial rate of escherichia coli improved from 35.9% to 79.1%; meanwhile, the biodegradability of the emulsion is improved, and the system stability is excellent when the emulsion is prepared; the modified alkyl di (aminoethyl) glycine effectively reduces the hardness of water from 19.3 to 7.6, converts hard water into soft water, and effectively relieves the skin problem caused by hard water washing and care.

Drawings

FIG. 1: scheme for the modification of alkylbis (aminoethyl) glycines.

FIG. 2: the bacteriostatic ratio of alkyl di (aminoethyl) glycine before and after modification is compared with that of alkyl di (aminoethyl) glycine.

Detailed Description

The present invention is described in detail below by way of examples, it should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and those skilled in the art can make some insubstantial modifications and adaptations of the present invention based on the above-mentioned disclosure.

Example 1

The preparation method of the surfactant comprises the following steps:

(1) dissolving alkyl di (aminoethyl) glycine in acetone to form a solution, continuously dropwise adding formic acid, controlling the dropwise adding speed to be 0.5g/min, heating to reflux after the dropwise adding is finished, reacting for 3 hours to form a cyclic intermediate, wherein the molar ratio of the alkyl di (aminoethyl) glycine to the formic acid is 1: 3.5;

(2) directly adding 50% glyoxylic acid aqueous solution after the reaction in the step (1), and carrying out reflux reaction for 5 hours, wherein the molar ratio of alkyl di (aminoethyl) glycine to glyoxylic acid is 1: 1;

(3) after the reaction in the step (2) is finished, adding sodium hydroxide or sodium bicarbonate to adjust the pH value of the reaction system to 10 until the system is layered, wherein the upper layer is an acetone phase, the lower layer is a water phase, removing the water phase, adding sodium bicarbonate with the mass concentration of 10% into the acetone phase, washing, adding activated carbon, adsorbing and filtering;

(4) and (3) dropwise adding deionized water into the filtrate at the dropping speed of 1g/min, continuously precipitating crystals in the dropwise adding process, controlling the temperature of the solution at 15 ℃ for crystal growth for 3 hours after the precipitation of the crystals is finished, filtering and collecting the crystals, and drying at the temperature of 50 ℃ and below-90 KPa.

Example 2

The preparation method of the surfactant comprises the following steps:

(1) dissolving alkyl di (aminoethyl) glycine in acetone to form a solution, continuously dropwise adding formic acid, controlling the dropwise adding speed to be 2g/min, heating to reflux after dropwise adding is finished, reacting for 5 hours to form a ring-shaped structural intermediate, wherein the molar ratio of the alkyl di (aminoethyl) glycine to the formic acid is 2: 5;

(2) directly adding 50% glyoxylic acid aqueous solution after the reaction in the step (1), and carrying out reflux reaction for 8 hours, wherein the molar ratio of alkyl di (aminoethyl) glycine to glyoxylic acid is 1: 1;

(3) after the reaction in the step (2) is finished, adding sodium hydroxide or sodium bicarbonate to adjust the pH value of the reaction system to 12 until the system is layered, wherein the upper layer is an acetone phase, the lower layer is a water phase, removing the water phase, adding sodium bicarbonate with the mass concentration of 20% into the acetone phase, washing, adding activated carbon, adsorbing and filtering;

(4) and (3) dropwise adding deionized water into the filtrate at a dropping speed of 3g/min, continuously precipitating crystals in the dropwise adding process, controlling the temperature of the solution at 20 ℃ for crystal growth for 1h after the precipitation of the crystals is finished, filtering and collecting the crystals, and drying at 60 ℃ below-90 KPa.

Example 3

The preparation method of the surfactant comprises the following steps:

(1) dissolving alkyl di (aminoethyl) glycine in acetone to form a solution, continuously dropwise adding formic acid, controlling the dropwise adding speed to be 1g/min, heating to reflux after the dropwise adding is finished, reacting for 4 hours to form a cyclic intermediate, wherein the molar ratio of the alkyl di (aminoethyl) glycine to the formic acid is 1: 4;

(2) directly adding 50% glyoxylic acid aqueous solution after the reaction in the step (1), and carrying out reflux reaction for 6 hours, wherein the molar ratio of alkyl di (aminoethyl) glycine to glyoxylic acid is 1: 1;

(3) after the reaction in the step (2) is finished, adding sodium hydroxide or sodium bicarbonate to adjust the pH value of the reaction system to 11 until the system is layered, wherein the upper layer is an acetone phase, the lower layer is a water phase, removing the water phase, adding sodium bicarbonate with the mass concentration of 15% into the acetone phase, washing, adding activated carbon, adsorbing and filtering;

(4) and (3) dropwise adding deionized water into the filtrate at the dropping speed of 2g/min, continuously precipitating crystals in the dropwise adding process, controlling the temperature of the solution at 18 ℃ for crystal growth for 1-3 h after the crystals are precipitated, filtering and collecting the crystals, and drying at the temperature of 55 ℃ and below-90 KPa.

Respectively adopting alkyl di (aminoethyl) glycine before and after modification to be dissolved in the same water, adopting a water hardness tester to detect the hardness of the water, and repeating each test for 5 times in order to ensure the accuracy of the data, wherein the specific data are shown in table 1.

Table 1: the effect of alkyldi (aminoethyl) glycine before and after modification on water hardness.

Generally, the hardness of water is divided into several stages: 0-4 degrees of the water is very soft water, 4-8 degrees of the water is soft water, 8-16 degrees of the water is medium hard water, and 16-30 degrees of the water is hard water.

The mineral components in the hard water are excessive, so that products such as facial cleanser and the like are not easy to bubble, the cleaning is not thorough, skin irritation is easy to cause after the mineral components are remained on the skin, skin dryness can be caused after long-term accumulation, skin irritation can be caused, or skin problems such as eczema, psoriasis and the like can be caused. From the data, the modified alkyl di (aminoethyl) glycine significantly reduces the hardness of water, converts hard water into soft water, and can effectively alleviate the skin problems caused by hard water.

And (3) antibacterial property detection: the bacteriostatic properties of the alkyl di (aminoethyl) glycine before and after modification on staphylococcus aureus and escherichia coli were tested, and the test results are shown in fig. 2. The antibacterial effect of the modified alkyl di (aminoethyl) glycine is remarkably improved, the antibacterial rate of staphylococcus aureus is improved by 1.95 times, and the antibacterial rate of escherichia coli is improved by 1.2 times compared with that before modification.

The modified alkyl di (aminoethyl) glycine prepared by the invention participates in the preparation of microemulsion, and the formula of the microemulsion is as follows: the microemulsion A is prepared from 12% of alkyl glycoside, 4% of capric triglyceride, 4% of sorbitol, 6% of protein extracting solution, 5% of ginkgo extracting solution, 5% of glycerol, 3% of hyaluronic acid, 3% of nicotinamide, 0.2% of hydrogenated castor oil, 0.05% of citric acid, 7% of modified alkyl di (aminoethyl) glycine prepared by the method and the balance of deionized water according to mass percentage.

In addition, linear alkyl di (aminoethyl) glycine is dissolved in acetone to form a solution, formic acid is continuously dripped, the dripping speed is controlled to be 1g/min, the temperature is raised to reflux after the dripping is finished, a ring-shaped structure intermediate is formed after the reaction is carried out for 4 hours, the molar ratio of the alkyl di (aminoethyl) glycine to the formic acid is 1:1, a glyoxylic acid solution with the mass concentration of 50 percent is directly added after the reaction is finished, and the reflux reaction is carried out for 6 hours, wherein the molar ratio of the alkyl di (aminoethyl) glycine to the glyoxylic acid is 1: 1; the modified alkyl di (aminoethyl) glycine in the emulsion A is replaced by the modified alkyl di (aminoethyl) glycine, and the microemulsion B is prepared by adopting the same process. And respectively taking the prepared microemulsion for centrifugal test: at normal temperature, 10g of each microemulsion prepared from the alkyl di (aminoethyl) glycine before and after modification is respectively filled into a centrifugal tube, the tubes are respectively placed in a centrifugal machine to be respectively centrifuged for 10min at the rotating speed of 1000-5000 rpm, an observation sample is taken out, and the detection structure is shown in table 2.

Table 2: and (5) testing the stability of the microemulsion at different rotating speeds.

From the data, the modified alkyl di (aminoethyl) glycine prepared by the invention is more excellent in qualitative property when participating in preparation of microemulsion, because an amino acid unit is additionally added in the modified alkyl di (aminoethyl) glycine, hydrophilic groups are added, and in the process of preparing microemulsion, when the modified alkyl di (aminoethyl) glycine is adsorbed on an interface, more hydrophilic groups are negatively charged to form a stronger electric double layer, and when ions with the same charge in the emulsion approach, the electric double layer generates electrostatic repulsion to prevent merging and agglomeration of the ions, and exists in a homogeneous form, so that the modified alkyl di (aminoethyl) glycine keeps excellent dispersion stability, and is not easy to generate problems of layering, sedimentation and the like.

In addition, since the amino acid structure is more easily degraded, absorbed and converted, two amino acid units are formed in the modified alkyldi (aminoethyl) glycine compared to the unmodified alkyldi (aminoethyl) glycine, increasing its biodegradability.

Claims

1. A surfactant characterized by: the structure of the modified alkyl di (aminoethyl) glycine is as follows:

。

2. the method for producing the surfactant according to claim 1, wherein: specifically, alkyl di (aminoethyl) glycine is used as a raw material, acetone is used as a solvent, the raw material reacts with formic acid to form a cyclic intermediate, the cyclic intermediate reacts with glyoxylic acid under the formic acid environment in a reflux manner, the pH value of the system is adjusted to 10-12, a water phase in the system is removed, sodium bicarbonate is added into the acetone phase for washing, deionized water is added into filtrate after filtration until crystals are not separated out, and the crystals are collected and dried; the reaction with formic acid is to dissolve alkyl di (aminoethyl) glycine in acetone, continuously dropwise add formic acid, control the dropwise adding speed to be 0.5-2 g/min, heat up to reflux after the dropwise adding is finished, and react for 3-5 h.

3. A process for preparing a surfactant according to claim 2, characterized in that: the molar ratio of the alkyl di (aminoethyl) glycine to the formic acid is 1-2: 53.5-5.

4. A process for producing the surfactant according to claim 1 or 2, characterized in that: after the reaction of the alkyl di (aminoethyl) glycine and formic acid is finished, a glyoxylic acid aqueous solution with the mass concentration of 50% is directly added, reflux reaction is carried out for 5-8 h, and the molar ratio of the alkyl di (aminoethyl) glycine to the glyoxylic acid is 1: 1.

5. A process for producing the surfactant according to any one of claims 1 to 3, characterized by: and the dropping speed of the deionized water is 1-3 g/min, crystals are continuously separated out in the dropping process, and after the crystals are separated out, the temperature of the solution is controlled to be 15-20 ℃ for crystal growing for 1-3 h.

6. The method for producing the surfactant according to claim 1, wherein: the drying is carried out at 50-60 ℃ and below-90 KPa.

7. The preparation method of the surfactant is characterized by comprising the following steps of: