阅读说明：本技术 一种可降解离子液体表面活性剂的合成方法及其应用 (Synthetic method and application of degradable ionic liquid surfactant ) 是由 付东 谢洋 王珏 阚侃 李鹏 杨帆 隋新 黄波 张晓臣 于 2020-05-28 设计创作，主要内容包括：一种可降解离子液体表面活性剂的合成方法及其应用,本发明涉及表面活性剂制备及其应用领域。本发明要解决现有离子液体表面活性剂降解性能差,对环境污染严重的技术问题。方法：溴乙醇与直链烷酸发生酯化反应得到长链酯基,然后与3-丁基吡啶烷基化反应,加入氨基酸钠盐通过半透膜置换溴离子,获得产品。本发明制备的可降解离子液体表面活性剂具有良好的表面活性,且结构中含有脂基易降解,具有良好的广谱抑菌性。本发明制备可降解型离子液体表面活性剂作为抑菌成分以及表面活性成分应用在洗护用品中。(The invention discloses a synthetic method and application of a degradable ionic liquid surfactant, and relates to the field of preparation and application of surfactants. The invention aims to solve the technical problems of poor degradation performance and serious environmental pollution of the existing ionic liquid surfactant. The method comprises the following steps: the bromoethanol and straight chain alkanoic acid are subjected to esterification reaction to obtain long chain ester group, then the long chain ester group is subjected to alkylation reaction with 3-butyl pyridine, and amino acid sodium salt is added to replace bromide ions through a semipermeable membrane to obtain the product. The degradable ionic liquid surfactant prepared by the invention has good surface activity, contains lipid groups in the structure, is easy to degrade, and has good broad-spectrum antibacterial activity. The degradable ionic liquid surfactant prepared by the invention is used as a bacteriostatic component and a surface active component applied to washing and caring articles.)

1. A synthetic method of a degradable ionic liquid surfactant is characterized by comprising the following steps:

adding bromoethanol and alkanoic acid into a reaction bottle, heating in a water bath until the temperature is 60-90 ℃, adding concentrated sulfuric acid, stirring and reacting for 6-24 hours, then washing with dichloromethane and deionized water in sequence, extracting a water phase, combining organic phases, and removing dichloromethane by rotary evaporation to obtain a crude product; adding the crude product into a methanol solution for recrystallization, and then repeatedly washing by adopting cooled anhydrous methanol to obtain ethyl bromoalkanoate;

adding 3-butylpyridine and ethyl bromoalkanoate prepared in the first step into toluene, heating and refluxing for reaction for 12-24 hours, removing the toluene solvent by rotary evaporation, and recrystallizing petroleum ether to obtain the N-ethyl alkanoate-3-butylpyridine bromide ionic liquid surfactant;

adding sodium amino acid and the N-ethyl alkanoate-3-butylpyridinium bromide ionic liquid surfactant obtained in the second step into a reaction bottle, adding an acetone solvent, stirring at normal temperature for 12-72 hours, filtering, then performing rotary evaporation on the filtrate to remove the solvent to obtain a solid, removing sodium bromide in the solid by using a semipermeable membrane, and recrystallizing petroleum ether to obtain the N-ethyl alkanoate-3-butylpyridinium amino acid ionic liquid surfactant, thereby completing the synthesis method of the degradable ionic liquid surfactant.

2. The method as claimed in claim 1, wherein the alkanoic acid in the step one is dodecanoic acid, tetradecanoic acid or hexadecanoic acid.

3. The method for synthesizing the degradable ionic liquid surfactant as claimed in claim 1, wherein the molar ratio of the bromoethanol to the linear alkanoic acid to the concentrated sulfuric acid in the step one is 1: 1.0-1.5: 0.01-0.05.

4. The method for synthesizing a degradable ionic liquid surfactant as claimed in claim 1, wherein when concentrated sulfuric acid is added in the first step, the reaction is stopped stirring for 1 minute every 2 hours, and water is removed from the bottom of the reaction flask.

5. The method for synthesizing a degradable ionic liquid surfactant as claimed in claim 1, wherein the water content of the methanol solution in the first step is 2%.

6. The method for synthesizing a degradable ionic liquid surfactant as claimed in claim 1, wherein the molar ratio of ethyl bromoalkanoate to 3-butylpyridine in the second step is (1-3) to 1.

7. The method for synthesizing the degradable ionic liquid surfactant as claimed in claim 1, wherein the sodium amino acid in step three is sodium glycinate, sodium alanine, sodium valine or sodium leucine.

8. The method for synthesizing a degradable ionic liquid surfactant according to claim 1, wherein the molar ratio of the sodium amino acid to the N-ethyl alkanoate-3-butylpyridinium bromide ionic liquid surfactant in step three is 1: 1.

9. The method for synthesizing a degradable ionic liquid surfactant according to claim 1, wherein the formula of the ionic liquid surfactant of ethyl-alkanoate-3-butylpyridinium amino acid salt prepared in the third step is as follows:

wherein n is 12-16; x^-Represents glycinate, alanate, valinate or leucinate.

10. The use of the synthetic degradable ionic liquid surfactant of claim 1, characterized in that said degradable ionic liquid surfactant is used as a bacteriostatic component and a surface active component in a cleaning product.

Technical Field

The invention relates to the field of preparation and application of surfactants.

Background

The surfactant, which is known as "industrial monosodium glutamate", is widely used in various fields of national economic development due to its functions of washing, wetting or anti-sticking, emulsifying or demulsifying, foaming or defoaming, solubilizing, dispersing, preserving, antistatic, etc. With the rapid development of science and technology and economy, the traditional surfactant cannot meet the production and living needs of people, and the requirement on the surfactant industry is higher and higher. The ionic liquid surfactant is a salt which is composed of an organic cation and an inorganic or organic anion and is in a liquid state at or near room temperature, and has the properties of both an ionic liquid and a surfactant. The ionic liquid surfactant is similar to the traditional cationic surfactant, consists of a charged hydrophilic head group and one or more hydrophobic chain(s), can be self-assembled in aqueous solution as a novel amphiphilic molecular compound, and has wide application in the aspects of nanoparticle synthesis, DNA extraction, emulsification, gene carrier and the like. At present, many ionic liquid surfactants containing heterocycles such as imidazole, pyridine, thiazole, quinoline, tetrahydropyrrole and piperidine have been reported, but most of the synthesized ionic liquid surfactants have poor degradation performance and great environmental pollution, so that the development of ionic liquid surfactants with novel structures and performance research thereof are hot spots in the research field.

Disclosure of Invention

The invention provides a synthetic method and application of a degradable ionic liquid surfactant, aiming at solving the technical problem that the existing ionic liquid surfactant has poor degradation performance and serious environmental pollution.

A synthetic method of a degradable ionic liquid surfactant specifically comprises the following steps:

adding bromoethanol and alkanoic acid into a reaction bottle, heating in a water bath until the temperature is 60-90 ℃, adding concentrated sulfuric acid, stirring and reacting for 6-24 hours, then washing with dichloromethane and deionized water in sequence, extracting a water phase, combining organic phases, and removing dichloromethane by rotary evaporation to obtain a crude product; adding the crude product into a methanol solution for recrystallization, and then repeatedly washing by adopting cooled anhydrous methanol to obtain ethyl bromoalkanoate;

adding 3-butylpyridine and ethyl bromoalkanoate prepared in the first step into toluene, heating and refluxing for reaction for 12-24 hours, removing the toluene solvent by rotary evaporation, and recrystallizing petroleum ether to obtain the N-ethyl alkanoate-3-butylpyridine bromide ionic liquid surfactant;

adding sodium amino acid and the N-ethyl alkanoate-3-butylpyridinium bromide ionic liquid surfactant obtained in the second step into a reaction bottle, adding an acetone solvent, stirring at normal temperature for 12-72 hours, filtering, then performing rotary evaporation on the filtrate to remove the solvent to obtain a solid, removing sodium bromide in the solid by using a semipermeable membrane, and recrystallizing petroleum ether to obtain the N-ethyl alkanoate-3-butylpyridinium amino acid ionic liquid surfactant, thereby completing the synthesis method of the degradable ionic liquid surfactant.

The preparation process of the degradable ionic liquid surfactant of the invention generates ester with 2-bromoethanol and dodecanoic acid, tetradecanoic acid or hexadecanoic acidThe reaction produces long chain ester groups (R) having 14, 16 and 18 carbon atoms₁) And then carrying out alkylation reaction with 3-butylpyridine to obtain the ionic liquid surfactant, and finally adding corresponding amino acid sodium salt to replace bromide ions through a semipermeable membrane, thereby preparing the degradable ionic liquid surfactant. The reaction process is as follows:

the bacteriostatic mechanism of the degradable ionic liquid surfactant is as follows: when bacteria or fungi are contacted with the prepared degradable ionic liquid surfactant, the degradable ionic liquid surfactant can be rapidly adsorbed to the surface of the bacteria or fungi (cell walls or cell membranes are usually negatively charged) due to positive charge of the degradable ionic liquid surfactant, and the butyl group enhances lipophilic interaction with phospholipids in the cell membranes due to introduction of a side chain butyl group at a meta position of the pyridine group by the surfactant. Therefore, the butyl is quickly embedded into the cell membrane of bacteria or fungi, the ionic liquid surfactant is reassembled with phospholipid molecules, the introduced butyl group has flexibility and can be entangled with the phospholipid molecules, the assembly structure is consolidated, the bacterial membrane is broken and the cytoplasm leaks after the assembly structure is completely reestablished, and the purpose of high-efficiency and durable bacteriostasis is achieved, so that the surfactant has bacteriostasis.

The invention has the beneficial effects that:

the degradable surfactant provided by the invention has the advantages of green and easily-obtained raw materials, simple preparation and route total yield of more than 90%.

The degradable ionic liquid surfactant provided by the invention has good surface activity, the structure contains lipid groups which are easy to degrade, and degradation products are saturated fatty acid, saturated fatty alcohol, water and carbon dioxide; the CMC of the degradable ionic liquid surfactant is 1-3 orders of magnitude lower than that of the traditional surfactant n-octyl trimethyl ammonium bromide.

The side chain butyl is introduced into the meta position of the pyridine group of the degradable ionic liquid surfactant, the lipophilic effect of phospholipid in a cell membrane is enhanced by the butyl group, so that after bacteria or fungi contact the degradable ionic liquid surfactant prepared by the method, the butyl is quickly embedded into the cell membrane of the bacteria or fungi, the ionic liquid surfactant is reassembled with phospholipid molecules, and the introduced butyl group has flexibility and can be entangled with the phospholipid molecules, so that the assembly structure is consolidated, the structure to be assembled is completely reestablished, and the bacterial membrane is ruptured to cause cytoplasmic leakage, thereby achieving the purposes of high efficiency and long-lasting bacteriostasis, so that the surfactant has good bacteriostasis and fungus effects and has broad-spectrum bacteriostasis on escherichia coli, bacillus subtilis, staphylococcus aureus and enterobacter aerogenes; has good inhibition effect on common fungi such as aspergillus niger, penicillium, candida albicans, saccharomycetes and the like.

The N-ethyl alkanoate-3-butyl pyridine amino acid salt ionic liquid surfactant obtained by the invention has good surface activity. The surface tension of the surfactant is measured by a ring pulling method, and the surface activity of the surfactant is evaluated. The experimental results show that: the Critical Micelle Concentration (CMC) of the degradable ionic liquid surfactant is 1-3 orders of magnitude lower than that of the traditional surfactant n-octyl trimethyl ammonium bromide, and the surface tension (gamma-gamma)_cmc) 30 to 36mN · m^-1。

The invention provides the degradable ionic liquid surfactant with good biodegradability. The biodegradability of the synthesized ionic liquid surfactant is measured by adopting a method of GB/T15818-2018 surfactant biodegradability test method. The experimental results show that: the degradable ionic liquid surfactant has a degradation rate of more than 90% in 7 days and is basically and completely degraded in 15 days.

The invention provides application of the degradable ionic liquid surfactant as a bacteriostatic agent. The antibacterial activity of the degradable ionic liquid surfactant on escherichia coli, bacillus subtilis, staphylococcus aureus and enterobacter aerogenes is measured by adopting an oxford cup diffusion method. The in vitro minimum inhibitory concentration method is adopted to determine the inhibitory activity of the degradable ionic liquid surfactant on fungi such as aspergillus niger, penicillium, candida albicans, saccharomycetes and the like. The experimental results show that: the surfactant has broad-spectrum antibacterial activity on the bacteria and fungi.

The degradable ionic liquid surfactant prepared by the invention is used as a bacteriostatic component and a surface active component and is applied to washing and caring articles.

Drawings

FIG. 1 is a surface tension-concentration graph of a surfactant prepared in example, wherein a pentagon represents example one, a circle represents example two, and a triangle represents example three.

Detailed Description

The technical solution of the present invention is not limited to the specific embodiments listed below, and includes any combination of the specific embodiments.