阅读说明：本技术 一种n-酰基氨基酸型表面活性剂的制备方法 (Preparation method of N-acyl amino acid type surfactant ) 是由 宋国强 谈颖 冯筱晴 唐龙 潘春 王志秀 李欢 张腾月 周峰 于 2021-01-28 设计创作，主要内容包括：本发明属于表面活性剂制备技术领域,具体涉及一种N-酰基氨基酸型表面活性剂的制备方法,该方法包括：将油脂、氨基酸供体、碱和水混合后在惰性氛围、加热、加压条件下反应3-15h得到混合物；将混合物与提纯剂混合,得到的沉淀经抽滤、润洗、干燥后得到N-酰基氨基酸型表面活性剂；氨基酸供体为氨基酸或氨基酸盐。本发明选用的原料简单、价格低廉,经一步反应得到N-酰基氨基酸或N-酰基氨基酸盐表面活性剂,得到的N-酰基氨基酸型表面活性剂的收率大于85%；产品提纯方法简单,制备方法的效率高；制备的N-酰基氨基酸型表面活性剂的活性物含量大于95%,满足社会需求。(The invention belongs to the technical field of surfactant preparation, and particularly relates to a preparation method of an N-acyl amino acid type surfactant, which comprises the following steps: mixing oil, an amino acid donor, alkali and water, and reacting for 3-15h under the conditions of inert atmosphere, heating and pressurization to obtain a mixture; mixing the mixture with a purifying agent, and carrying out suction filtration, rinsing and drying on the obtained precipitate to obtain an N-acyl amino acid type surfactant; the amino acid donor is amino acid or amino acid salt. The raw materials selected by the invention are simple and low in cost, and the N-acylamino acid or N-acylamino acid salt surfactant is obtained through one-step reaction, and the yield of the obtained N-acylamino acid type surfactant is more than 85%; the product purification method is simple, and the preparation method has high efficiency; the active matter content of the prepared N-acyl amino acid type surfactant is more than 95 percent, and the social requirement is met.)

1. A process for producing an N-acyl amino acid type surfactant, which comprises,

s1: mixing oil, an amino acid donor, alkali and water, and reacting for 3-15 hours in an inert atmosphere under the conditions of heating and pressurizing to obtain a mixture;

s2: mixing the mixture with a purifying agent, and carrying out suction filtration, rinsing and drying on the obtained precipitate to obtain an N-acyl amino acid type surfactant;

the amino acid donor is amino acid or amino acid salt.

2. The method according to claim 1, wherein in step S1, the oil or fat is one or more of coconut oil, palm oil, and palm kernel oil.

3. The method according to claim 1, wherein in step S1, the amino acid is one or more of glycine, sarcosine or L-alanine; the amino acid salt is one or more of sodium glycinate, potassium glycinate, sodium sarcosinate, potassium sarcosinate, L-sodium alanine or L-potassium alanine.

4. The method according to claim 1, wherein in step S1, the amino acid donor is an amino acid.

5. The method according to claim 4, wherein in step S1, the molar ratio of the oil/fat, the amino acid, and the alkali is 0.7 to 1:3 to 6:3.3 to 6.6; the weight ratio of the grease to the water is 1: 2-4.

6. The method according to claim 5, wherein in step S1, the molar ratio of the oil/fat, the amino acid, and the base is 1:3: 3.3.

7. The method according to claim 1, wherein the reaction temperature in step S1 is 160 to 200 ℃.

8. The method according to claim 1, wherein the reaction pressure in step S1 is 3 to 5 MPa.

9. The method according to claim 1, wherein in step S2, the purifying agent is an acid; the acid is used for adjusting the pH value of the mixture to 1-5; the N-acyl amino acid type surfactant is an N-acyl amino acid surfactant.

10. The method according to claim 1, wherein in step S2, the purifying agent is an organic solvent; the organic solvent is methanol or acetone; the N-acyl amino acid type surfactant is an N-acyl amino acid salt surfactant.

Technical Field

The invention relates to the technical field of surfactant preparation, in particular to a preparation method of an N-acyl amino acid type surfactant.

Background

The amino acid type surfactant is a novel green environment-friendly surfactant derived from renewable biomass, and is an upgraded and updated product of the traditional surfactant. Since the surfactant is an amphoteric substance which uses carboxyl as anion and ammonium salt as cation, the surfactant has many excellent characteristics such as reproducibility, low irritation, low toxicity, good biocompatibility, good biodegradability and environmental compatibility, and is the first choice among foods, medicines and cosmetics. Because the amino acid structure is various, and the fatty acid chain can change the structure length and the number, the wide structure diversity and different physicochemical and biological properties are shown, which brings more possibility for the wide use of the amino acid type surfactant.

N-acyl amino acid type anionic surfactants, such as coconut oil sodium glycinate, coconut oil sodium glutamate, lauroyl sodium glycinate and the like are commercially available amino acid surfactants at present, have the characteristics of excellent performance, mildness to hair and skin, high affinity, good antibacterial property, good wetting effect and the like, and are main raw materials of cosmetics such as shampoo, shower gel and the like. At present, the industrial and laboratory synthesis of N-acylamino acid type anionic surfactants mainly adopts a Schotten-Baumann condensation method, takes fatty acid or grease as a raw material, performs acyl chlorination under the action of acylating reagents such as thionyl chloride, phosphorus trichloride, phosphorus pentachloride, phosphorus oxychloride, oxalyl chloride and the like, and then performs condensation, acidification and salt forming reactions to prepare N-acylamino acid salts (see a reaction formula 1). The process has the advantages of simple process flow and equipment, mild reaction conditions and the deficiency that strong irritant and corrosive acylating reagents such as thionyl chloride need to be used; the quality requirement on natural oil is high, the natural oil is difficult to store, hydrolysis byproducts are easily introduced in the reaction, the color and luster of the product are poor, peculiar smell is generated, and the application range of the product is influenced; halogen such as chlorine is used in the reaction, and the halogen is not completely removed in the reaction process, so that the product quality is influenced, and the application range of the product is limited.

Reaction scheme 1

Patent 201110162138.8 discloses a method for preparing N-natural oil-based amino acid surfactant from oil, wherein the oil is mainly coconut oil/soybean oil/peanut oil/castor oil/palm oil or olive oil, the sodium amino acid is mainly sodium salt of glycine/glutamic acid/alanine/sarcosine, the catalyst is composed of metal oxide and carrier, wherein the metal oxide is potassium/sodium/magnesium/strontium oxide, the carrier is 4A zeolite, the molar ratio of the reaction temperature raw materials is: 1: 2.2-6, the reaction temperature is 120-250 ℃, the reaction time is 3-12 h, and the adding amount of the catalyst is 0.1-5 wt% of the total amount of reactants. However, the metal oxide adopted by the method is easy to absorb water, has high requirements on reaction conditions, and consumes the discharged 4A zeolite, thereby being an extra burden on the environment and the ecology; in addition, the method does not provide a method for further purifying the product, and the low purity of the product can cause the product to generate peculiar smell and reduce the melting point of the product, thereby limiting the application range of the product.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides the preparation method of the N-acyl amino acid type surfactant with mild reaction conditions, simple process, high yield and high product purity.

In order to solve the defects of the prior art, the technical scheme provided by the invention is as follows:

the invention provides a preparation method of an N-acyl amino acid type surfactant, which comprises the following steps

S1: mixing oil, an amino acid donor, alkali and water, and reacting for 3-15 hours in an inert atmosphere under the conditions of heating and pressurizing to obtain a mixture;

s2: mixing the mixture with a purifying agent, and carrying out suction filtration, rinsing and drying on the obtained precipitate to obtain an N-acyl amino acid type surfactant;

the amino acid donor is amino acid or amino acid salt.

Preferably, in step S1, the oil and fat is one or more of coconut oil, palm oil, and palm kernel oil.

Preferably, in the step S1, the amino acid is one or more of glycine, sarcosine or L-alanine; the amino acid salt is one or more of sodium glycinate, potassium glycinate, sodium sarcosinate, potassium sarcosinate, L-sodium alanine or L-potassium alanine.

Preferably, in step S1, the amino acid donor is an amino acid.

Preferably, in the step S1, the molar ratio of the oil, the amino acid and the alkali is 0.7 to 1:3 to 6:3.3 to 6.6; the weight ratio of the grease to the water is 1: 2-4.

Preferably, in the step S1, the molar ratio of the oil/fat, the amino acid, and the base is 1:3: 3.3.

Preferably, in the step S1, the reaction temperature is 160 to 200 ℃.

Preferably, in the step S1, the reaction pressure is 3 to 5 Mpa.

Preferably, in step S2, the purifying agent is an acid; the acid is used for adjusting the pH value of the mixture to 1-5; the N-acyl amino acid type surfactant is an N-acyl amino acid surfactant.

Preferably, in step S2, the purifying agent is an organic solvent; the organic solvent is methanol or acetone; the N-acyl amino acid type surfactant is an N-acyl amino acid salt surfactant.

The invention has the beneficial effects that:

1) the raw materials selected by the invention are simple and low in cost, and the N-acyl amino acid type surfactant is obtained through one-step reaction, and the yield of the obtained N-acyl amino acid type surfactant is more than 85%;

2) the product purification method provided by the invention is simple, and the efficiency of the preparation method is further improved;

3) the active matter content of the N-acyl amino acid type surfactant prepared by the invention is more than 95%, and the social requirement is met.

Drawings

FIG. 1 is a flow chart of a process for preparing an N-acyl amino acid type surfactant according to the present invention;

figure 2 infrared spectrum of sodium cocoanut oil glycinate prepared from example 1.

Detailed Description

The present invention will be further described with reference to the following embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and the protection scope of the present invention is not limited thereby.

The embodiment of the invention provides a preparation method of an N-acyl amino acid type surfactant, which is shown in figure 1 and comprises the following steps:

the method comprises the following steps: mixing oil, an amino acid donor, alkali and water, and reacting for 3-15 hours under the conditions of inert atmosphere, heating and pressurization to obtain a mixture. Wherein the amino acid donor is amino acid or amino acid salt.

Specifically, in a reaction kettle provided with a stirring device, grease, an amino acid donor, alkali and deionized water are sequentially added, air in the reaction kettle is replaced by nitrogen for 3 times, the reaction is carried out for 3-15 hours under heating and pressurizing conditions, and the reaction is cooled to room temperature. Under pressurized reaction, the inert atmosphere will be relatively safe. In addition, the grease is easily oxidized at high temperature, and the inert gas can play a role in protection.

Preferably, the oil or fat is one or more of coconut oil, palm oil or palm kernel oil.

Preferably, the amino acid is one or more of glycine, sarcosine or L-alanine; the amino acid salt is one or more of sodium glycinate, potassium glycinate, sodium sarcosinate, potassium sarcosinate, L-sodium alanine or L-potassium alanine.

Preferably, the amino acid donor is an amino acid. This is because the price of amino acid salts is much higher than that of amino acids, which increases the cost of the surfactant; if the amino acid salt is synthesized first, the reaction steps are increased, and the generated amino acid salt is hard in texture and inconvenient to use subsequently.

Preferably, the base is an inorganic base, such as sodium hydroxide or potassium hydroxide.

Taking the reaction of grease, glycine, water and sodium hydroxide as an example, the grease and glycine generate sodium N-acyl glycinate and glycerol under the conditions of inert atmosphere, heating and pressurization, and the reaction formula is as follows:

wherein R represents an alkyl group of an oil or fat, that is, an alkyl group of a saturated or unsaturated, linear or branched fatty acid constituting the oil or fat.

Preferably, the molar ratio of the oil to the amino acid to the base is 0.7-1: 3-6: 3.3-6.6.

Preferably, the molar ratio of the oil, the amino acid and the base is 1:3: 3.3.

Preferably, the weight ratio of the grease to the water is 1: 2-4.

Preferably, the reaction temperature is 160-200 ℃.

Preferably, the reaction temperature is 180 ℃.

Preferably, the reaction pressure is 3-5 Mpa. The pressurization enables the water to be maintained in a liquid state at high temperature, namely the whole reaction system is maintained in a liquid state, and the whole reaction can be ensured to be carried out at a high reaction rate.

Preferably, the reaction pressure is 3.5 MPa.

Step two: and mixing the mixture with a purifying agent, and carrying out suction filtration, rinsing and drying on the obtained precipitate to obtain the N-acyl amino acid type surfactant.

Specifically, the purifying agent is acid or organic solvent, different types of N-acyl amino acid type surfactants can be obtained, and the type of the purifying agent can be selected according to needs.

The precipitate is preferably rinsed with cyclohexane.

When the purifying agent is acid, the purifying steps are as follows: and (3) adjusting the pH of the mixture to 1-5 by using acid, removing floating white foam on the upper layer, performing suction filtration to obtain a white solid, and further rinsing the white solid by using cyclohexane to remove residual glycerol and unreacted grease to obtain the N-acylamino acid surfactant. Wherein, the acid is used for neutralizing the unreacted alkali and simultaneously converting the N-acyl amino acid salt in the mixture into the N-acyl amino acid, thereby being convenient for separating out the N-acyl amino acid.

Preferably, when acid is selected for purification, the pH of the mixture is adjusted to 1-2 by using acid, so that the N-acylamino acid is precipitated conveniently.

Preferably, the acid is concentrated hydrochloric acid.

When the purifying agent is an organic solvent, the purifying steps are as follows: pouring the reaction liquid into an organic solvent, and carrying out suction filtration, cyclohexane rinsing and drying on the obtained precipitate to obtain the N-acyl amino acid salt surfactant. The organic solvent is used to precipitate the surfactant N-acylamino acid salt, and the cyclohexane is used to remove the residual glycerin and unreacted oil and fat, and further purify the N-acylamino acid salt. Wherein the organic solvent is methanol or acetone.

The invention uses K1160 Kjeldahl azotometer to measure the active matter content of N-acyl amino acid type surfactant, and the specific steps are as follows: sampling, digesting and testing. Sampling: taking 0.1g of a sample to be detected, and adding 5g of potassium sulfate, 0.3g of copper sulfate and 10mL of concentrated sulfuric acid for later use; digestion parameters: keeping the temperature at 250 ℃ for 30min, then heating to 380 ℃ and keeping the temperature for 60min, and finishing digestion; testing parameters: 20mL of boric acid, 25mL of water, 40mL of 40% (w/w) sodium hydroxide solution, 5min of distillation time, and 0.117mol/L of titrated acid.

The reagents used in the following examples are all commercially available.

Example 1:

in a reaction kettle provided with a stirring device, 0.01mol of coconut oil, 0.03mol of glycine, 0.033mol of NaOH and 20mL of deionized water are sequentially added, air in a reaction container is replaced by nitrogen for 3 times, the mixture is heated to 180 ℃ and reacts for 12 hours, and the reaction pressure is 3.5 Mpa. After the reaction was completed, it was cooled to room temperature to obtain a mixture. And pouring the mixture into acetone, separating out a solid, performing suction filtration while the mixture is hot, rinsing the solid twice with cyclohexane, and drying to obtain the coconut oil sodium glycinate surfactant with the yield of 89.3%. The content of active matter in the coconut oil sodium glycinate surfactant is 95.3 percent through the test of a Kjeldahl azotometer.

FIG. 2 is an infrared spectrum of sodium cocoanut glycinate, wherein 3344cm^-1Is N-H telescopic vibration absorption peak, 1557cm^-1Is the N-H deformation vibration absorption peak, 1620cm^-1C ═ O stretching vibration peak of typical amide ester bond, and is 1597cm^-1The absorption peak at (A) is the C ═ O stretching vibration peak of carboxyl, 1247cm^-1Is a C-O carboxylic acid characteristic absorption peak of 2800-2900 cm^-1Is a C-H stretching vibration absorption peak. Compared with coconut oil, the coconut oil is 3344cm^-1And 1557cm^-1The new peak at (a) indicates the formation of the amide bond, confirming the formation of sodium N-acylglycinate.

Example 2:

sequentially adding 0.007mol of coconut oil, 0.06mol of glycine, 0.066mol of NaOH and 15mL of deionized water into a reaction kettle provided with a stirring device, replacing air in the reaction vessel with nitrogen for 3 times, heating to 200 ℃ and reacting for 15h, wherein the reaction pressure is 4 Mpa. After the reaction was completed, it was cooled to room temperature to obtain a mixture. And pouring the mixture into 150mL of water, adjusting the pH value to about 1-2 by using concentrated hydrochloric acid, removing the floating white foam on the upper layer at the moment, performing suction filtration to obtain a white solid, and rinsing and drying the white solid by using cyclohexane to obtain the cocoanut oil glycine surfactant with the yield of 86.4%. The active matter content of the coconut oil glycine surfactant is 93.7 percent through the test of a Kjeldahl azotometer.

Example 3:

0.01mol of palm oil, 0.03mol of sarcosine, 0.033mol of KOH and 20mL of deionized water are sequentially added into a reaction kettle provided with a stirring device, air in the reaction container is replaced by nitrogen for 3 times, the mixture is heated to 180 ℃ and reacts for 12 hours, and the reaction pressure is 3.5 Mpa. After the reaction was completed, it was cooled to room temperature to obtain a mixture. And pouring the mixture into 150mL of water, adjusting the pH value to about 1-2 by using concentrated hydrochloric acid, removing the floating white foam on the upper layer at the moment, performing suction filtration to obtain a white solid, and rinsing and drying the white solid by using cyclohexane to obtain the palm oil sarcosine surfactant with the yield of 88.6%. The active matter content of the palm oil sarcosine surfactant is 94.1 percent through the test of a Kjeldahl azotometer.

Example 4:

adding 0.01mol of palm kernel oil, 0.03mol of L-alanine, 0.033mol of NaHOH0.033mol and 20mL of deionized water into a reaction kettle provided with a stirring device in sequence, replacing air in the reaction container with nitrogen for 3 times, heating to 180 ℃ and reacting for 12 hours, wherein the reaction pressure is 3.5 Mpa. After the reaction was completed, it was cooled to room temperature to obtain a mixture. And pouring the mixture into methanol, separating out a solid, performing suction filtration while the mixture is hot, rinsing the solid twice with cyclohexane, and drying to obtain the palm kernel oil sodium alanine surfactant with the yield of 87.1%. The content of active substances of the palm kernel oil sodium alanine surfactant is 93.9 percent through the test of a Kjeldahl azotometer.

Example 5:

0.01mol of palm oil, 0.03mol of glycine, 0.033mol of KOH and 20mL of deionized water are sequentially added into a reaction kettle provided with a stirring device, air in the reaction container is replaced by nitrogen for 3 times, the mixture is heated to 160 ℃ and reacts for 3 hours, and the reaction pressure is 3 Mpa. After the reaction was completed, it was cooled to room temperature to obtain a mixture. And pouring the mixture into acetone, separating out a solid, performing suction filtration while the mixture is hot, rinsing the solid twice with cyclohexane, and drying to obtain the palm oil sodium glycinate surfactant with the yield of 86.5%. The content of active substances of the palm oil sodium glycinate surfactant is 94.8 percent through the test of a Kjeldahl azotometer.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.