阅读说明：本技术 一种可降解的双子表面活性剂及其制备方法 (Degradable gemini surfactant and preparation method thereof ) 是由 肖龙强 凌坤华 侯琳熙 范阳海 李陈陈 纪明智 李伟 张荣翠 于 2021-08-18 设计创作，主要内容包括：本发明公开了一种可降解的双子表面活性剂及其制备方法,制备步骤如下：(1)在氮气保护下,将二醇类物质干燥后置于反应釜中；(2)将路易斯酸碱对催化剂和反应单体Ⅰ混合后溶解在反应溶剂中,再注入反应釜中,与二醇类物质发生聚合反应,再加入反应单体Ⅱ,继续发生聚合反应；(3)反应结束后,向反应液中加入反应溶剂和醋酸,滤除不溶物,减压蒸馏除去溶剂,即得可降解的双子表面活性剂。本发明中的制备方法可连续反应,生成的中间产物无需进行纯化,便可直接进行下一步的合成反应,整个反应过程在一个容器中即可完成,无需进行转接。本发明简化了双子表面活性剂的合成工艺,操作简单,可重复性强,易降解,降低了能耗,便于规模化生产。(The invention discloses a degradable gemini surfactant and a preparation method thereof, and the preparation method comprises the following steps: (1) under the protection of nitrogen, drying the diol substances and then placing the diol substances into a reaction kettle; (2) mixing a Lewis acid-base pair catalyst and a reaction monomer I, dissolving the mixture in a reaction solvent, injecting the mixture into a reaction kettle, carrying out polymerization reaction with diol substances, adding a reaction monomer II, and continuing to carry out polymerization reaction; (3) and after the reaction is finished, adding a reaction solvent and acetic acid into the reaction solution, filtering out insoluble substances, and removing the solvent by reduced pressure distillation to obtain the degradable gemini surfactant. The preparation method can continuously react, the generated intermediate product can be directly subjected to the next synthetic reaction without purification, and the whole reaction process can be finished in one container without transfer. The invention simplifies the synthesis process of the gemini surfactant, has simple operation, strong repeatability and easy degradation, reduces the energy consumption and is convenient for large-scale production.)

1. A degradable gemini surfactant is characterized in that the structural formula is as follows:

or

Wherein R is₁Is ethyl or phenyl.

2. A method of making the degradable gemini surfactant of claim 1, comprising the steps of:

(1) under the protection of nitrogen, drying the diol substances and then placing the diol substances into a reaction kettle;

(2) mixing a Lewis acid-base pair catalyst and a reaction monomer I, dissolving the mixture in a reaction solvent, injecting the mixture into a reaction kettle, carrying out polymerization reaction with diol substances, adding a reaction monomer II, and continuing to carry out polymerization reaction;

(3) and after the reaction is finished, adding a reaction solvent and acetic acid into the reaction solution, filtering out insoluble substances, and removing the solvent by reduced pressure distillation to obtain the degradable gemini surfactant.

3. The method of claim 2, wherein the surfactant is selected from the group consisting of: the reaction monomer I is lactide or caprolactone; the reaction monomer II is ethylene oxide.

4. The method of claim 2, wherein the surfactant is selected from the group consisting of: the reaction solvent is tetrahydrofuran.

5. The method of claim 2, wherein the surfactant is selected from the group consisting of: the Lewis acid-base pair catalyst is prepared from P (R)₂)₃And an organoborane, wherein R₂Is dimethylamino or diethylamino.

6. The method of claim 5, wherein the surfactant is selected from the group consisting of: the organoborane is triethylboron.

7. The method of claim 2, wherein the surfactant is selected from the group consisting of: the molar ratio of the Lewis acid to the base to the catalyst, the diol substances and the reaction monomer I is (1-3): (0.5-1.5): (1-100): (1-100).

8. The method of claim 2, wherein the surfactant is selected from the group consisting of: the polymerization temperature is 0-40 ℃, and the reaction time is 12-48 h.

Technical Field

The invention belongs to the technical field of surfactant synthesis, and particularly relates to a degradable gemini surfactant and a preparation method thereof.

Background

The surfactant (surfactant) is a substance capable of remarkably reducing the surface tension of a target solution, has fixed hydrophilic and lipophilic groups, and can be directionally arranged on the surface of the solution. The molecular structure of the surfactant has an amphoteric nature: one end is a hydrophilic group and the other end is a hydrophobic group. The surfactant has a series of physical and chemical effects of wetting or anti-sticking, emulsifying or demulsifying, foaming or defoaming, solubilizing, dispersing, washing, corrosion prevention, antistatic and the like and corresponding practical application, so that the surfactant becomes a flexible and diversified fine chemical product with wide application. The gemini surfactant is a surfactant formed by linking two or more same or almost same surfactant monomers together through chemical bonds with the amphiphilic components at or near the hydrophilic head group by using a linking group. In the case of reduced amounts, gemini surfactants can achieve effects that even exceed the conventional amounts of single-chain surfactants. The extremely low CMC value enables the gemini surfactant to form micelles at a very low concentration so as to achieve the effect of solubilization. Therefore, gemini surfactants can be used as highly effective solubilizers, degreasers and emulsifiers. In addition, the gemini surfactant has excellent dispersibility and high permeability. However, gemini surfactants are relatively stable substances, and have certain difficulty in preparation, purification and decomposition.

Patent CN105777563A discloses a method for preparing gemini surfactant, comprising the following steps: (1) synthesis of intermediate N- (3-chloro-2-hydroxypropyl) -N, N-dimethyloctanylammonium chloride (2) Synthesis of Gemini surfactant N, N' -bis (octyldimethyl) -2-hydroxy-1, 3-dichloropropanediammonium salt. The gemini surfactant prepared by the preparation method of the gemini surfactant has good water solubility, and can form solutions with different mass fractions with water; the surfactant has small molecular weight and low viscosity, and is favorable for penetration in a rock formation; active chemical property containing active group-OH; and the ammonium salt is beneficial to plant growth, and is safe and pollution-free. However, the reaction of the technical scheme is discontinuous, after the reaction in the step (1) is finished, evaporation, extraction and purification are needed, and then the chemical reaction in the step (2) is carried out, so that the operation is complex and the time consumption is long. In addition, 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.

Disclosure of Invention

In order to solve the technical problems, the invention provides a degradable gemini surfactant and a preparation method thereof. Polylactic acid or polycaprolactone is used as a middle hydrophobic chain, polyethylene glycol is arranged at the periphery, and the degradable gemini surfactant is synthesized under the action of Lewis acid and base on a catalyst. The preparation method can continuously react, the generated intermediate product can be directly subjected to the next synthetic reaction without purification, and the whole reaction process can be finished in one container without transfer. The invention simplifies the synthesis process of the gemini surfactant, has simple operation, strong repeatability and easy degradation, reduces the energy consumption and is convenient for large-scale production.

The technical scheme provided by the invention is as follows:

a degradable gemini surfactant has the following structural formula:

wherein R is₁Is ethyl or phenyl.

A method for preparing the degradable gemini surfactant comprises the following steps:

(1) under the protection of nitrogen, drying the diol substances and then placing the diol substances into a reaction kettle;

(2) mixing a Lewis acid-base pair catalyst and a reaction monomer I, dissolving the mixture in a reaction solvent, injecting the mixture into a reaction kettle, carrying out polymerization reaction with diol substances, adding a reaction monomer II, and continuing to carry out polymerization reaction;

(3) and after the reaction is finished, adding a reaction solvent and acetic acid into the reaction solution, filtering out insoluble substances, and removing the solvent by reduced pressure distillation to obtain the degradable gemini surfactant.

Preferably, the reactive monomer I is lactide or caprolactone; the reaction monomer II is ethylene oxide.

Preferably, the reaction solvent is tetrahydrofuran.

Preferably, the Lewis acid-base pair catalyst is formed from P (R)₂)₃And an organoborane, wherein R₂Is dimethylamino or diethylamino.

Preferably, the organoborane is triethylboron.

Preferably, the molar ratio of the Lewis acid-base pair catalyst, the diol substance, the reaction monomer I and the reaction monomer II is (1-3): (0.5-1.5): (1-100): (1-100).

Preferably, the polymerization reaction temperature is 0-40 ℃, and the reaction time is 12-48 h.

Compared with the prior art, the invention has the following technical advantages:

(1) the invention adopts polylactic acid or polycaprolactone as the middle hydrophobic chain, both of which have good biodegradability, and the prepared gemini surfactant is easy to degrade, has no pollution to the environment, and is safe and environment-friendly.

(2) According to the invention, Lewis acid and base are adopted to synthesize the gemini surfactant with the catalyst, the whole preparation method can realize continuous reaction, the generated intermediate product can directly perform the next polymerization reaction without purification, and the whole reaction process can be completed in the same container without switching.

(3) The gemini surfactant prepared by the method is a brand-new material, has strong variability and is widely applied. It can be used as efficient solubilizer, degreasing agent and emulsifier. The gemini surfactant has high surface activity and high emulsifying efficiency when used as an emulsifier. Under the condition of reducing the dosage, the effect even exceeding the conventional dosage of the single-chain surfactant can be achieved. The extremely low CMC value enables the gemini surfactant to form micelles at a very low concentration so as to achieve the effect of solubilization.

Drawings

FIG. 1 is a schematic view of the polymerization process in examples 1 and 4 of the present invention

FIG. 2 is a schematic view of a polymerization process in example 2 of the present invention

FIG. 3 is a schematic view of a polymerization process in example 3 of the present invention

FIG. 4 is a schematic view of a polymerization process in example 5 of the present invention

FIG. 5 is a schematic view of a polymerization process in example 6 of the present invention

FIG. 6 is the nuclear magnetic hydrogen spectrum of the polyethylene glycol-b-polycaprolactone prepared by the present invention

Wherein: the hydrogen peaks of the linking group ethyl can be seen at chemical shifts 1.67ppm and 3.49ppm, the hydrogen peaks of ethylene glycol can be seen at 4.08ppm, 3.61ppm, 2.50ppm, the hydrogen peaks of polylactic acid can be seen at 1.31ppm, 2.63ppm, and the hydrogen peaks of polycaprolactone can be seen at 4.53ppm, 1.48ppm, 5.60ppm, and 1.63ppm, all of which indicate successful preparation of polyethylene glycol-b-polycaprolactone.

FIG. 7 is the nuclear magnetic hydrogen spectrum of gemini surfactant prepared by the invention

Wherein: the successful preparation of the gemini surfactant was demonstrated by the peaks of hydrogen at the benzene ring of the linker group at a chemical shift of 7.0ppm, ethylene glycol at 4.36ppm, 3.81ppm, 2.64ppm, and polylactic acid at 1.37ppm, 1.61ppm, 180ppm, 2.40ppm, and 4.11 ppm.

FIG. 8 is a GPC chart of gemini surfactant obtained in example 3 of the present invention

Wherein: the absorption peak at the leaching time of 24.5min represents the gemini surfactant prepared by the invention, and the chromatographic purity of the prepared gemini surfactant is 100 percent through measurement.

Detailed Description

The salient features and the considerable advances of the invention are further clarified below by the examples, which are intended to be illustrative only and not limiting.

Example 1

A method of making a degradable gemini surfactant comprising the steps of:

(1) under the protection of nitrogen, ethylene glycol (0.06mL, 1.0mmol) is dried and then put into a 100mL pressure-resistant reaction kettle;

(2) mixing tris (dimethylamino) phosphonium (0.16g, 1.0mmol), triethylborane (2.94g, 3.0mmol) and lactide (1.4g, 10.0mmol), dissolving in 3.0mL tetrahydrofuran, injecting into a pressure-resistant reaction vessel, and reacting at room temperature for 48 h; after the reaction is finished, dissolving ethylene oxide (0.5mL, 10.0mmol) in 1mL tetrahydrofuran, injecting into a pressure-resistant reaction kettle, and reacting for 48h at room temperature;

(3) after the reaction was completed, tetrahydrofuran and a little acetic acid were added, insoluble matter was filtered off, and the solvent was removed by distillation under reduced pressure to obtain the final polymer gemini surfactant (1.54 g). The product yield is 80.72% by calculation; by determination, M_n，GPC＝1500g mol^-1。

Example 2

A method of making a degradable gemini surfactant comprising the steps of:

(1) under the protection of nitrogen, resorcinol (0.08mL, 1.0mmol) is dried and then put into a 100mL pressure-resistant reaction kettle;

(2) mixing tris (dimethylamino) phosphonium (0.16g, 1.0mmol), triethylborane (2.94g, 3.0mmol) and lactide (1.4g, 10.0mmol), dissolving in 3.0mL tetrahydrofuran, injecting into a pressure-resistant reaction vessel, and reacting at room temperature for 48 h; after the reaction is finished, dissolving ethylene oxide (0.5mL, 10.0mmol) in 1mL tetrahydrofuran, injecting into a pressure-resistant reaction kettle, and reacting for 48h at room temperature;

(3) after the reaction is finished, adding tetrahydrofuran and a little acetic acid, filtering out insoluble substances, and removing the solvent by reduced pressure distillation to obtain the final polymer gemini surfactant (1.63g), wherein the product yield is 83.89% by calculation; by determination, M_n，GPC＝1600g mol^-1。

Example 3

A method of making a degradable gemini surfactant comprising the steps of:

(1) under the protection of nitrogen, hydroquinone (0.08mL, 1.0mmol) is dried and then put into a 100mL pressure-resistant reaction kettle;

(2) mixing tris (dimethylamino) phosphonium (0.16g, 1.0mmol), triethylborane (2.94g, 3.0mmol) and lactide (1.4g, 10.0mmol), dissolving in 3.0mL tetrahydrofuran, injecting into a pressure-resistant reaction vessel, and reacting at room temperature for 48 h; after the reaction is finished, dissolving ethylene oxide (0.5mL, 10.0mmol) in 1mL tetrahydrofuran, injecting into a pressure-resistant reaction kettle, and reacting for 48h at room temperature;

(3) after the reaction is finished, adding tetrahydrofuran and a little acetic acid, filtering out insoluble substances, and removing the solvent by reduced pressure distillation to obtain the final polymer gemini surfactant (1.58g), wherein the product yield is 81.31 percent by calculation; measured, Mn, GPC 1600g mol^-1。

Example 4

A method of making a degradable gemini surfactant comprising the steps of:

(1) under the protection of nitrogen, ethylene glycol (0.06mL, 1.0mmol) is dried and then put into a 100mL pressure-resistant reaction kettle;

(2) mixing tris (diethylamino) phosphorus (0.24g, 1.0mmol), triethylborane (2.94g, 3.0mmol) and lactide (1.4g, 10.0mmol), dissolving in 3.0mL of tetrahydrofuran, injecting into a pressure-resistant reaction vessel, and reacting at room temperature for 48 hours; after the reaction is finished, dissolving ethylene oxide (0.5mL, 10.0mmol) in 1mL tetrahydrofuran, injecting into a pressure-resistant reaction kettle, and reacting for 48h at room temperature;

(3) after the reaction is finished, adding tetrahydrofuran and a little acetic acid, filtering out insoluble substances, and removing the solvent by reduced pressure distillation to obtain the final polymer gemini surfactant (1.60g), wherein the product yield is 83.86% by calculation; by determination, M_n，GPC＝1600g mol^-1。

Example 5

A method of making a degradable gemini surfactant comprising the steps of:

(1) under the protection of nitrogen, ethylene glycol (0.06mL, 1.0mmol) is dried and then put into a 100mL pressure-resistant reaction kettle;

(2) mixing tris (dimethylamino) phosphonium (0.16g, 1.0mmol), triethylborane (2.94g, 3.0mmol) and caprolactone (1.1g, 10.0mmol), dissolving in 3.0mL tetrahydrofuran, injecting into a pressure-resistant reaction kettle, and reacting at room temperature for 48 h; after the reaction is finished, dissolving ethylene oxide (0.5mL, 10.0mmol) in 1mL tetrahydrofuran, injecting into a pressure-resistant reaction kettle, and reacting for 48h at room temperature;

(3) after the reaction is finished, adding tetrahydrofuran and a little acetic acid, filtering out insoluble substances, and removing the solvent by reduced pressure distillation to obtain the final polymer gemini surfactant (1.39g), wherein the product yield is 86.45% by calculation; by determination, M_n，GPC＝1400g mol^-1。

Example 6

A method of making a degradable gemini surfactant comprising the steps of:

(1) under the protection of nitrogen, resorcinol (0.08mL, 1.0mmol) is dried and then put into a 100mL pressure-resistant reaction kettle;

(2) mixing tris (dimethylamino) phosphonium (0.16g, 1.0mmol), triethylborane (2.94g, 3.0mmol) and caprolactone (1.1g, 10.0mmol), dissolving in 3.0mL tetrahydrofuran, injecting into a pressure-resistant reaction kettle, and reacting at room temperature for 48 h; after the reaction is finished, dissolving ethylene oxide (0.5mL, 10.0mmol) in 1mL tetrahydrofuran, injecting into a pressure-resistant reaction kettle, and reacting for 48h at room temperature;

(3) after the reaction is finished, adding tetrahydrofuran and a little acetic acid, filtering out insoluble substances, and removing the solvent by reduced pressure distillation to obtain the final polymer gemini surfaceActivator (1.38g), calculated product yield 83.99%; by determination, M_n，GPC＝1400g mol^-1。