A bio-based surfactant and its preparation method and application

Abstract

The invention belongs to the technical field of bio-based surfactants, discloses a bio-based surfactant and its preparation method and application, the preparation method comprises the following steps: step one: dissolve diglyceryl peptide methyl ester hydrochloride in dichloromethane, add triethylamine, dehydroabietic acid and 2-(7-benzotriazole oxide)-N,N,N',N'-tetramethyluronium hexafluorophosphate in sequence, and react for 1-3 hours at 40-50 DEG C; step two: cool to room temperature after the reaction is completed, extract the product with dichloromethane, and then remove dichloromethane to obtain a viscous intermediate product after washing and drying; step three: add ethanol and sodium hydroxide to the viscous intermediate product, react for 1-5 hours at 60-80 DEG C, and obtain a bio-based surfactant after filtering and drying after the reaction is completed. The present invention can obtain a natural product surfactant with good biocompatibility by simple reaction, and after compounding with choline chloride, a carbon nanotube dispersant with good solubility can be obtained, which can be applied to multiple fields such as electronics, cleaning, and coating.

Description

Technical field:

[0001] The present invention belongs to the technical field of bio-based surfactants, and in particular relates to a bio-based surfactant and a preparation method and application thereof. Background technology:

[0002] Carbon nanotubes (CNTs) have a unique tubular structure, which makes them show great application potential in many fields such as nanotechnology, material strengthening, energy storage, catalysis, sensor technology, luminophores, conductive coatings and biomedical nanotechnology. Usually, carbon nanotubes need to be made into dispersions before use. Due to the strong van der Waals force between carbon nanotubes, it is difficult to disperse carbon nanotubes. Therefore, it is usually necessary to change the surface properties of carbon nanotubes or add specific ingredients to prepare a uniform carbon nanotube dispersion solution. At present, there are two main methods for dispersing carbon nanotubes. One is covalent modification, which connects certain functional groups to carbon nanotubes through specific chemical reactions to change the interaction between carbon nanotubes; the other is non-covalent modification, which adsorbs dispersant molecules on the surface of carbon nanotubes through intermolecular interactions to achieve a dispersion effect. Surfactants are one of the commonly used dispersants. The hydrophobic part of the surfactant binds to the surface of carbon nanotubes through van der Waals interactions, while the hydrophilic part helps to disperse in water. The dispersing effect of surfactants is closely related to the molecular structure of surfactants. For example, sodium dodecyl sulfate and sodium dodecylbenzene sulfonate have completely different surfaces in terms of dispersing carbon nanotubes, although there is only one benzene ring difference in their molecular structures.

[0003] With the development of modern science and technology, it is very important to develop efficient and novel carbon nanotube dispersants. However, from the current research status, carbon nanotube dispersants are still limited to traditional alkane chain surfactants. In addition, some surfactants have environmental pollution and poor degradability during use. Therefore, how to develop environmentally friendly surfactants with new structures and use them in the dispersion process of carbon nanotubes is a key issue facing this field.

[0004] Rosin is a natural product extracted from pine trees, mainly composed of resin acids. Rosin is abundant and widely used in many fields such as food, medicine, cosmetics, rubber, ink, papermaking, etc. Rosin resin acid contains a carboxyl group and is a rigid structure connected by three rings with significant hydrophobicity. Choline chloride is a B vitamin compound essential to organisms and plays an important role in biological metabolic processes and cell membrane functions. In animal husbandry, choline chloride is used as a feed additive to promote animal health and improve production performance. The present invention uses disproportionated rosin as a raw material and reacts with a dipeptide amino acid to obtain a green surfactant. The surfactant is then mixed with choline chloride in a certain proportion to obtain a stable, environmentally friendly carbon nanotube dispersion.

[0005] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention:

[0006] The object of the present invention is to provide a bio-based surfactant and a preparation method and application thereof, so as to overcome the defects in the above-mentioned prior art.

[0007] In order to achieve the above object, the present invention provides a bio-based surfactant, the molecular structure of which is shown in the following formula:

[0008]

[0009] The present invention also provides a method for preparing a bio-based surfactant, comprising the following steps:

[0010] Step 1: dissolve diglycine methyl ester hydrochloride in dichloromethane, add triethylamine, dehydroabietic acid and 2-(7-oxybenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate in sequence, and react at 40-50°C for 1-3 hours;

[0011] Step 2: After the reaction is completed, the product is cooled to room temperature, extracted with dichloromethane, washed with water, dried, and then dichloromethane is removed to obtain a viscous intermediate product;

[0012] Step 3: Add ethanol and sodium hydroxide to the viscous intermediate product, react at 60-80° C. for 1-5 hours, and filter and dry after the reaction to obtain the bio-based surfactant.

[0013] The reaction route from step 1 to step 3 is shown below:

[0014]

[0015] Zhishang New Materials Technology (Dongtai) Co., Ltd. Further, as a preference, the dehydroabietic acid in the step 1 can be tetrahydroabietic acid, abietic acid, pimaric acid or other rosin derivatives.

[0016] Furthermore, preferably, in the step 1, the usage ratio of diglycine methyl ester hydrochloride, triethylamine, dehydroabietic acid and 2-(7-oxybenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate is 1.5:1:1:1.

[0017] The present invention also provides an application of a bio-based surfactant, wherein the bio-based surfactant is used for preparing a carbon nanotube dispersion.

[0018] The preparation method of the carbon nanotube dispersion is as follows:

[0019] Step 1: adding a bio-based surfactant and choline chloride in a molar ratio of 1:0.5-1.5 to an acetone solution and stirring for 3-15 hours, filtering and evaporating to obtain a colloidal solid, which is a bio-based carbon nanotube dispersant;

[0020] Step 2: dissolving the bio-based carbon nanotube dispersant obtained in step 1 in water to prepare a dispersant aqueous solution with a mass concentration of 1-5%;

[0021] Step 3: Add the dispersant aqueous solution obtained in step 2 into the carbon nanotubes and disperse them evenly to obtain a carbon nanotube dispersion.

[0022] In the step 3, the mass ratio of the dispersant to the carbon nanotubes in the dispersant aqueous solution is 1:1-10.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The present invention uses rosin derivatives and simple dipeptide molecules as raw materials, and can obtain rosin-based amino acid surfactants with good biocompatibility through simple reactions. The yield is high and meets the requirements of green chemistry.

[0025] (2) The present invention combines the rosin-based amino acid surfactant with choline chloride to obtain a carbon nanotube dispersant with good solubility. The carbon nanotubes can be well dispersed at a relatively low concentration and can be stable for more than 12 months at 30°C.

[0026] (3) The carbon nanotube dispersants of the present invention are all made of environmentally friendly raw materials, have good solubility and compatibility, and the obtained carbon nanotube dispersion can be compounded with a variety of other ingredients and can be applied to multiple fields such as electronics, cleaning, and coating. Description of the drawings:

[0027] Figure 1is the nuclear magnetic spectrum of the rosin-based amino acid surfactant in the present invention;

[0028] Figure 2 This is a photo of the appearance of the environmentally friendly carbon nanotube dispersant of the present invention at 25°C;

[0029] Figure 3 This is a photograph of the appearance of the carbon nanotube dispersion liquid dispersed by sodium dodecylbenzene sulfonate (left) and the environmentally friendly carbon nanotube dispersant (right) in the present invention after being left to stand for 12 months;

[0030] Figure 4 This is a graph showing the change in viscosity of the environmentally friendly carbon nanotube dispersant at 200 mM as a function of shear rate. Specific implementation method:

[0031] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0032] A brief summary of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceived aspects, and is neither intended to identify the key or critical elements of all aspects nor to define the scope of any or all aspects. Its only purpose is to give some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be given later.

[0033] Embodiment 1:

[0034] Weigh 25.6g, 0.14mol of diglycine methyl ester hydrochloride (simple dipeptide molecule) and dissolve it in dichloromethane. Add 85g of triethylamine and 72g of dehydroabietic acid (rosin derivative) in sequence, and then add 100g of 2-(7-oxybenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU). Raise the temperature to 45°C and react for 6h.

[0035] After the reaction was cooled to room temperature, the product was extracted with dichloromethane, and the organic layer was washed with water for 3 times, and the organic layer was dried over anhydrous sodium sulfate, filtered, and the filtrate was collected; then the dichloromethane was removed by rotary evaporation, and the product was purified by column chromatography (the eluent was petroleum ether: ethyl acetate = 2:1); the eluent was freed from the solvent under reduced pressure to obtain a viscous intermediate product with a yield of 72.5%;

[0036] Weigh 67g of the viscous intermediate product into a three-necked flask, then add 200mL of ethanol and 12g of sodium hydroxide, and react at 70°C for 4 hours. After the reaction is completed, evaporate the solvent and dry the residue in a vacuum drying oven to obtain a rosin-based amino acid surfactant as a white solid with a yield of 95.1%. Figure 1From the NMR spectrum, we can see that the purity of the product is above 95%, which fully meets the requirements of subsequent experiments.

[0037] The reaction route is shown below:

[0038]

[0039] Embodiment 2:

[0040] Weigh 10 g of the rosin-based amino acid surfactant and 3.2 g of choline chloride prepared in Example 1, add them to 60 mL of acetone solution, stir at room temperature for 5 hours, filter out the inorganic salt precipitate, evaporate the filtrate to dryness, and obtain a colloidal solid, which is an environmentally friendly carbon nanotube dispersant, with a yield of 92%;

[0041] Take an appropriate amount of environmentally friendly carbon nanotube dispersant and dissolve it in water to prepare a solution with a mass concentration of 3%. Let it stand for 24 hours, 1 month, 3 months, and 6 months to observe the dissolution. Figure 2 As shown, Figure 2 From left to right are photos of the samples left standing for 24 hours, photos of the samples left standing for 1 month, photos of the samples left standing for 3 months, and photos of the samples left standing for 6 months; Figure 2 It can be seen that the solution is clear and transparent, indicating that the dispersant has good water solubility. Even after standing for 6 months, the solution remains clear and transparent.

[0042] To a glass bottle containing 10 mL of water, 0.1 g of carbon nanotubes, 0.025 g of sodium dodecylbenzene sulfonate and the above-mentioned environmentally friendly carbon nanotube dispersant were added respectively, and the system state was observed at room temperature after being dispersed for 5 minutes using a homogenizer. Figure 3 It can be seen that after standing at 30°C for 12 months, the carbon nanotubes dispersed by sodium dodecylbenzene sulfonate have precipitated, but the carbon nanotubes dispersed by the environmentally friendly bio-based dispersant still remain in a uniform and stable state, indicating that the bio-based dispersant has a better dispersion effect.

[0043] In addition, the carbon nanotube dispersant prepared by the present invention is applied to a low-viscosity system, and the transparent solution formed by the carbon nanotube dispersant has a relatively low viscosity. Figure 4 It can be seen that when the solution concentration is 200 mM, the solution viscosity is 0.02 Pa·s.

[0044] From the above results, it can be seen that the present invention uses rosin derivatives and simple dipeptide molecules as raw materials, and can obtain rosin-based amino acid surfactants with good biocompatibility through simple reactions, with high yields, meeting the requirements of green chemistry. After the rosin-based amino acid surfactant is compounded with choline chloride, a carbon nanotube dispersant with good solubility can be obtained, which can well disperse carbon nanotubes at a relatively low concentration and can be stable for more than 12 months at 30°C.

[0045] The carbon nanotube dispersants of the present invention are all made of environmentally friendly raw materials, have good solubility and compatibility, and the obtained carbon nanotube dispersion can be compounded with a variety of other ingredients and can be applied to multiple fields such as electronics, cleaning, and coating.

[0046] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A bio-based surfactant, characterized in that: The molecular structure of the bio-based surfactant is shown below:

2. A method for preparing a bio-based surfactant, characterized in that: The following steps are involved: Step 1: dissolve diglycine methyl ester hydrochloride in dichloromethane, add triethylamine, dehydroabietic acid and 2-(7-oxybenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate in sequence, and react at 40-50°C for 1-3 hours; Step 2: After the reaction is completed, the product is cooled to room temperature, extracted with dichloromethane, washed with water, dried, and then dichloromethane is removed to obtain a viscous intermediate product; Step 3: Add ethanol and sodium hydroxide to the viscous intermediate product, react at 60-80° C. for 1-5 hours, and filter and dry after the reaction to obtain the bio-based surfactant.

3. The method for preparing a bio-based surfactant according to claim 2, characterized in that: The reaction route from step 1 to step 3 is shown below:

4. The method for preparing a bio-based surfactant according to claim 2, characterized in that: The purity of the bio-based surfactant obtained in step three is greater than 95%.

5. An application of a bio-based surfactant, characterized in that: The bio-based surfactant is used for preparing carbon nanotube dispersion.

6. The use of a bio-based surfactant according to claim 5, characterized in that: The preparation method of the carbon nanotube dispersion is as follows: Step 1: adding a bio-based surfactant and choline chloride in a molar ratio of 1:0.5-1.5 to an acetone solution and stirring for 3-15 hours, filtering and evaporating to obtain a colloidal solid, which is a bio-based carbon nanotube dispersant; Step 2: dissolving the bio-based carbon nanotube dispersant obtained in step 1 in water to prepare a dispersant aqueous solution with a mass concentration of 1-5%; Step 3: Add the dispersant aqueous solution obtained in step 2 into the carbon nanotubes and disperse them evenly to obtain a carbon nanotube dispersion.

7. The use of a bio-based surfactant according to claim 6, characterized in that: In the step, a bio-based surfactant and choline chloride are mixed in a molar ratio of 1:

1.

8. The use of a bio-based surfactant according to claim 6, characterized in that: In the step 3, the mass ratio of the dispersant to the carbon nanotubes in the dispersant aqueous solution is 1:1-10.

9. The use of a bio-based surfactant according to claim 6, characterized in that: In the step 3, the mass ratio of the dispersant to the carbon nanotubes in the dispersant aqueous solution is 1:3.

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