Very long chain glycolipid nonionic surfactants and methods for their synthesis

Abstract

The application discloses a super-long chain glucose amide nonionic surfactant and a synthesis method thereof. The hydrophobic tail chain of the surfactant is derived from plant-based fatty acids such as oleic acid, erucic acid or nervonic acid, and the hydrophilic head group is derived from glucose derivatives such as meglumine and glycolglucamine. With oleic acid, erucic acid and nervonic acid in rapeseed by-product as hydrophobic tail chain raw material, glucose derivatives meglumine and glycolglucamine as hydrophilic head group raw material, methanol, ethanol, ethylene glycol or propylene glycol (single solvent or binary mixed solvent) as solvent, and DMAP or NaF as catalyst, a kind of bio-based surfactant is obtained. The super-long chain glucose amide nonionic surfactant is prepared by selective amination reaction, the hydroxyl group in the glucose amine molecule does not need to be protected complicatedly, the reaction temperature is close to room temperature, the operation is simple, and the purification process only needs a simple industrial crystallization method, which is suitable for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of surfactant preparation, specifically relating to an ultra-long chain glucosamide nonionic surfactant. Background Technology

[0002] Surfactants, often referred to as "industrial MSG," are widely used in food processing, daily chemicals, and biopharmaceuticals. However, with the gradual depletion of petroleum resources, the production of traditional petroleum-derived surfactants is becoming increasingly limited, especially petroleum-based surfactants such as linear alkylbenzene sulfonates (LAS), alkyl sulfates (AS), and alkylphenol polyoxyethylene ethers (APE). These surfactants exhibit poor biodegradability and potential toxicity to aquatic organisms. Therefore, the development of renewable, environmentally friendly, and easily degradable green surfactants is particularly urgent.

[0003] Synthesizing glucose-based surfactants from starch hydrolysis has become a preferred alternative to petroleum-based surfactants. Compared to traditional petroleum-based surfactants, glucose-based surfactants not only exhibit superior biodegradability but also demonstrate lower safety, toxicity, and irritation to humans, making them a new focus of surfactant research. In particular, ultra-long-chain (≥C18) glucose-based nonionic surfactants have attracted significant attention due to their extremely long hydrophobic tail chains, resulting in extremely low critical micelle concentrations (CMCs) and significant viscoelasticity, gelling properties, and shear-thinning characteristics. The hydrophobic tail chains of these surfactants cannot be obtained from petroleum cracking products but can only be derived from byproducts of natural vegetable oils (such as oleic acid, erucic acid, and nervonic acid in rapeseed and peanut oils). Therefore, the key raw materials for ultra-long-chain glucose-based nonionic surfactants are not only renewable but also environmentally friendly and readily biodegradable, meeting the requirements of green chemistry and sustainable development. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing an ultra-long chain glucamide nonionic surfactant and its synthesis method, so as to obtain an environmentally friendly and easily degradable green surfactant.

[0005] This invention provides an ultra-long chain glucamide nonionic surfactant, the structure of which is shown in the following formula:

[0006]

[0007] In the structural formula, R1 in the hydrophilic head group is CH3 or CH2CH3;

[0008] In the aforementioned structural formula, the hydrophobic tail chain is characterized by containing one unsaturated bond, and n is 1, 5, or 7.

[0009] The present invention provides a method for preparing an ultralong-chain glucosamide nonionic surfactant, comprising the following steps:

[0010] Step 1

[0011] Add meglumine or meglumine to a solvent, and add DMAP or NaF as a catalyst. Mix and activate the amine groups by high-shear stirring at 10-30 °C for 20-40 min to obtain solution A; dissolve oleic acid, erucic acid or nervonic acid in a solvent to obtain solution B.

[0012] Step 2

[0013] Solution A and solution B are mixed by high-shear stirring and reacted at 10-30 °C for 8-24 hours. After the reaction is completed, the organic solvent is removed to obtain the crude product of ultra-long chain glucamide nonionic surfactant.

[0014] Step 3

[0015] The crude product was dissolved in dichloromethane, and acetone was slowly added dropwise at 15-45 °C to crystallize the product, resulting in a purified ultra-long chain glucamide nonionic surfactant.

[0016] In the above method, the mass ratio of meglumine or meglumine to its solvent in step 1 is 1:(50~60); the mass ratio of meglumine or meglumine to the catalyst is 1:(0.002~0.003).

[0017] In the above method, further, the molar ratio of oleic acid, erucic acid or nervonic acid to meglumine or meglumine in step 1 is 1:(0.8~0.95); the mass ratio of oleic acid, erucic acid or nervonic acid to its solvent is 1:(20~30).

[0018] In the above method, the solvent in step 1 is at least one of methanol, ethanol, ethylene glycol, and propylene glycol.

[0019] In the above method, further, the high-shear method described in step 1 uses a high-shear mixer to mix at 8000~12000 rpm and 25°C for 30 min to obtain solution A.

[0020] In the above method, further, in step 2, oleic acid, erucic acid or nervonic acid are dissolved in a solvent and ultrasonically mixed by an ultrasonic mixer to obtain solution B.

[0021] In the above method, further, in step 2, solution A and solution B are mixed and sheared at 25 °C and 8000~12000 rpm using a high-shear mixer until they are fully mixed and homogeneous.

[0022] In the above method, step 2, the method for removing organic solvents, is vacuum distillation.

[0023] In the above method, the mass ratio of crude product to dichloromethane in step 3 is 1:(45~55); the mass ratio of acetone to dichloromethane added is 1:(0.5~0.8).

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The ultra-long chain glucamide nonionic surfactant described in this invention has abundant and inexpensive raw materials, meets environmental protection requirements, has good biodegradability and safety, and is suitable for the development of novel functional surfactants.

[0026] 2. The ultra-long-chain glucamide nonionic surfactant described in this invention, as an environmentally friendly surfactant, has the following advantages:

[0027] It is gentle on the skin and has minimal irritation.

[0028] Excellent wetting and solubilizing properties;

[0029] It exhibits good interfacial activity in oil-water systems;

[0030] It exhibits strong resistance to hard water;

[0031] The hydrophobic tail chain is an ultra-long carbon chain (≥C18) containing unsaturated bonds, which has good rheological modification properties and better low-temperature solubility than ultra-long saturated carbon chain surfactants.

[0032] 3. In the method of the present invention, the amidation reaction of meglumine and meglumine with fatty acids is a selective reaction, which does not require complex protection treatment of the hydroxyl groups in the sugar molecules, making the operation simple and suitable for industrial production. Attached Figure Description

[0033] Figure 1 The ultra-long chain glucosamide nonionic surfactant UC synthesized in Example 1 of this invention 18 The hydrogen nuclear magnetic resonance spectrum of GMe.

[0034] Figure 2 The ultra-long chain glucosamide nonionic surfactant UC synthesized in Example 2 of this invention 18 The proton NMR spectrum of GEt.

[0035] Figure 3 The ultra-long chain glucosamide nonionic surfactant UC synthesized in Example 3 of this invention 22 The hydrogen nuclear magnetic resonance spectrum of GMe.

[0036] Figure 4 The ultra-long chain glucosamide nonionic surfactant UC synthesized in Example 4 of this invention 22 The proton NMR spectrum of GEt.

[0037] Figure 5 The ultra-long chain glucosamide nonionic surfactant UC synthesized in Example 6 of this invention 24 The proton NMR spectrum of GEt.

[0038] Figure 6 The ultra-long chain glucosamide nonionic surfactant UC synthesized in Example 1 of this invention 18 High-resolution mass spectrometry of GMe.

[0039] Figure 7 The ultra-long chain glucosamide nonionic surfactant UC synthesized in Example 2 of this invention 18 High-resolution mass spectrometry of GEt.

[0040] Figure 8 The ultra-long chain glucosamide nonionic surfactant UC synthesized in Example 3 of this invention 22 High-resolution mass spectrometry of GMe.

[0041] Figure 9 The ultra-long chain glucosamide nonionic surfactant UC synthesized in Example 4 of this invention 22 High-resolution mass spectrometry of GEt.

[0042] Figure 10 The ultra-long chain glucosamide nonionic surfactant UC synthesized in Example 5 of this invention 24 High-resolution mass spectrometry of GMe.

[0043] Figure 11 The ultra-long chain glucosamide nonionic surfactant UC synthesized in Example 6 of this invention 24 High-resolution mass spectrometry of GEt. Detailed Implementation

[0044] The present invention will be further described in detail below with reference to the embodiments, but the embodiments of the present invention are only examples and the scope of protection of the present invention is not limited thereto.

[0045] Example 1

[0046] Ultra-long chain glucamide nonionic surfactant UC 18 GMe, its structural formula is:

[0047]

[0048] Preparation method:

[0049] Step 1: Dissolve 1 g meglumine in 50 g methanol, add 0.002 g DMAP, and mix for 30 min at 25 °C and a high shear rate of 8000 rpm to obtain solution A; dissolve 1.81 g oleic acid in 36.2 g methanol, and then sonicate for 30 min to obtain solution B.

[0050] Step 2: Mix solution A and solution B at 25 °C. Mix at a high shear rate of 10,000 rpm for 30 minutes. After mixing, place the mixture under magnetic stirring at 200 rpm and lower the reaction temperature to 10 °C, continuing the reaction for 12 hours. After the reaction is complete, subject the mixture to vacuum distillation at 40 °C to obtain 2.30 g of a yellow paste-like crude product.

[0051] Step 3: Dissolve the obtained crude product in 102.5 g of dichloromethane, and then slowly add 205 g of acetone at 15 °C to obtain a white solid; then dry under reduced pressure at 35 °C to obtain 2.05 g of white solid, with a yield of 87%.

[0052] 1 H NMR (400 MHz, CDCl3): δ 5.37 – 5.28 (m, 2H), 4.11 (br., 1H), 3.80 –3.65 (m, 5H), 3.10 (br., 2H), 2.65 (s, 1H), 2.13 (br., 2H), 2.00 – 1.99 (m,4H), 1.52 (br., 2H), 1.26 (br., 20H), 0.87 (t, J = 6.6 Hz, 3H). C 25 H 49 HRMS (m / z) results for NO6: [M+H] + Theoretical value: 460.3633; Experimental value: 460.3633.

[0053] Example 2

[0054] Ultra-long chain glucamide nonionic surfactant UC 18 GEt, its structural formula is:

[0055]

[0056] Preparation method:

[0057] Step 1: Dissolve 1 g of meglumine in 60 g of ethanol, add 0.003 g of DMAP, and then mix for 30 min at 25 °C and a high shear rate of 8000 rpm to obtain solution A; dissolve 1.50 g of oleic acid in 45 g of ethanol, and then sonicate for 30 min to obtain solution B.

[0058] Step 2: Mix solution A and solution B at 25 °C. Mix at a high shear rate of 10,000 rpm for 30 minutes. After mixing, place the mixture under magnetic stirring at 200 rpm and lower the reaction temperature to 20 °C, continuing the reaction for 12 hours. After the reaction is complete, subject the mixture to vacuum distillation at 40 °C to obtain 2.18 g of a yellow paste-like crude product.

[0059] Step 3: Dissolve the obtained crude product in 102 g of dichloromethane, and then slowly add 204 g of acetone at 15 °C to obtain a white solid; then dry under reduced pressure at 45 °C to obtain 2.04 g of white solid, with a yield of 90%.

[0060] 1 H NMR (400 MHz, CDCl3): δ 5.37 – 5.28 (m, 2H), 4.12 (br., 1H), 3.81 –3.66 (m, 5H), 3.10 (br., 2H), 3.00 (br., 2H), 2.13 (t, J = 7.0 Hz, 2H), 2.00– 1.97 (m, 4H), 1.52 (br., 2H), 1.26 (br., 20H), 0.87 (t, J = 6.6 Hz, 2H).C 26 H 51 HRMS (m / z) results for NO6: [M+H] + Theoretical value: 474.3789; Experimental value: 474.3789.

[0061] Example 3

[0062] Ultra-long chain glucamide nonionic surfactant UC 22 GMe, its structural formula is:

[0063]

[0064] Preparation method:

[0065] Step 1: Dissolve 1 g meglumine in 50 g methanol, add 0.0025 g DMAP, and mix for 30 min at 25 °C and a high shear rate of 8000 rpm to obtain solution A; dissolve 1.83 g erucic acid in 40 g methanol, and then sonicate for 30 min to obtain solution B.

[0066] Step 2: Mix solution A and solution B at 25 °C. Mix at a high shear rate of 10,000 rpm for 30 minutes. After mixing, place the mixture under magnetic stirring at 200 rpm and continue the reaction at 25 °C for 12 hours. After the reaction is complete, distill the mixture under reduced pressure at 40 °C to obtain 2.65 g of a yellow paste-like crude product.

[0067] Step 3: Dissolve the obtained crude product in 123 g of dichloromethane, and then slowly add 246 g of acetone at 25 °C to obtain a pale yellow solid; then dry under reduced pressure at 45 °C to obtain 2.46 g of pale yellow solid, with a yield of 93%.

[0068] 1 H NMR (400 MHz, CDCl3): δ, 5.38 – 5.30 (m, 2H), 4.11 (br., 1H), 3.80– 3.65 (m, 5H), 3.10 (br., 2H), 2.65 (s, 3H), 2.14 (br., 2H), 2.01 – 1.98 (m,4H), 1.52 (br., 2H), 1.25 (br., 20H), 0.87 (t, J = 6.6 Hz, 3H). C 29 H 57 HRMS (m / z) results for NO6: [M+H] + Theoretical value: 516.4259; Experimental value: 516.4259.

[0069] Example 4

[0070] UC, an ultra-long chain glucose-based surfactant 22 GEt, its structural formula is:

[0071]

[0072] Preparation method:

[0073] Step 1: Dissolve 1 g of meglumine in 55 g of ethylene glycol, add 0.028 g of DMAP, and mix for 30 min at 25 °C and a high shear rate of 8000 rpm to obtain solution A; dissolve 1.80 g of erucic acid in 50 g of ethylene glycol, and then sonicate for 30 min to obtain solution B.

[0074] Step 2: Mix solution A and solution B at 25 °C. Mix at a high shear rate of 12,000 rpm for 30 minutes. After mixing, place the mixture under magnetic stirring at 200 rpm and continue the reaction at 20 °C for 12 hours. After the reaction is complete, distill the mixture under reduced pressure at 80 °C to obtain 2.41 g of a yellow paste-like crude product.

[0075] Step 3: Dissolve the obtained crude product in 107.5 g of dichloromethane, and then slowly add 134.38 g of acetone at 25 °C to obtain a pale yellow-white solid; then dry under reduced pressure at 45 °C to obtain 2.15 g of pale yellow solid, with a yield of 85%.

[0076] 1 H NMR (400 MHz, CDCl3): δ, 5.38 – 5.33 (m, 2H), 4.15 (br., 1H), 3.85– 3.69 (m, 5H), 3.13 (br., 2H), 3.03 (br., 2H), 2.18 (br., 2H), 2.03 (dd, J =11.8, 6.4 Hz, 2H), 1.55 (br., 2H), 1.27 – 1.24 (m, 31H), 0.90 (t, J = 6.8 Hz, 3H). C 31 H 61 HRMS (m / z) results for NO6: [M+H] + Theoretical value: 531.4493; Experimental value: 531.4493.

[0077] Example 5

[0078] Ultra-long chain glucamide nonionic surfactant UC 24 GMe, its structural formula is:

[0079]

[0080] Preparation method:

[0081] Step 1: Dissolve 1 g meglumine in 50 g propylene glycol, add 0.0028 g DMAP, and then mix at 25 °C and a high shear rate of 8000 rpm for 30 min to obtain solution A; dissolve 1.98 g nervonic acid in 57 g methanol, and then sonicate for 30 min to obtain solution B.

[0082] Step 2: Mix solution A and solution B at 25 °C. Mix at a high shear rate of 12,000 rpm for 30 minutes. After mixing, place the mixture under magnetic stirring at 200 rpm and continue the reaction at 25 °C for 12 hours. After the reaction is complete, distill the mixture under reduced pressure at 40 °C to obtain 2.70 g of a yellow paste-like crude product.

[0083] Step 3: Dissolve the obtained crude product in 130 g of dichloromethane, and then slowly add 260 g of acetone at 45 °C to obtain a white solid; then dry under reduced pressure at 45 °C to obtain 2.59 g of white solid crude product, with a yield of 93%.

[0084] 1 H NMR (400 MHz, CDCl3): δ, 5.38 – 5.30 (m, 2H), 4.12 (br., 1H), 3.81– 3.66 (m, 5H), 3.10 (br., 2H), 2.65 (s, 3H), 2.13 (br., 2H), 2.01 (dd, J =11.8, 6.4 Hz, 4H), 1.52 (br., 2H), 1.26 – 1.25 (m, 32H), 0.87 (t, J = 6.8 Hz, 3H). C 31 H 61 HRMS (m / z) for NO6: [M+H] + Theoretical value: 544.4572; Experimental value: 544.4572.

[0085] Example 6

[0086] Ultra-long chain glucamide nonionic surfactant UC 24 GEt, its structural formula is:

[0087]

[0088] Preparation method:

[0089] Step 1: Dissolve 1 g of meglumine in 55 g of ethanol, add 0.025 g of DMAP, and then mix for 30 min at 25 °C and a high shear rate of 8000 rpm to obtain solution A; dissolve 1.84 g of nervonic acid in 52 g of ethylene glycol, and then sonicate for 30 min to obtain solution B.

[0090] Step 2: Mix solution A and solution B at 25 °C. Mix at a high shear rate of 12,000 rpm for 30 minutes. After mixing, place the mixture under magnetic stirring at 200 rpm and lower the reaction temperature to 20 °C for 12 hours. After the reaction is complete, distill the mixture under reduced pressure at 40 °C to obtain 2.51 g of a yellow paste-like crude product.

[0091] Step 3: Dissolve the obtained crude product in 123 g of dichloromethane, and then slowly add 246 g of acetone at 45 °C to obtain a white solid; then dry under reduced pressure at 45 °C to obtain 2.45 g of white solid, with a yield of 92%.

[0092] 1 H NMR (400 MHz, CDCl3): δ, 5.38 – 5.30 (m, 2H), 4.13 (br., 1H), 3.82– 3.67 (m, 5H), 3.10 (br., 2H), 3.01 (br., 2H), 2.13 (br., 2H), 2.01 (dd, J =11.8, 6.4 Hz, 2H), 1.52 (br., 2H), 1.26 – 1.24 (m, 35H), 0.87 (t, J = 6.8 Hz, 3H). C 31 H 61 HRMS (m / z) for NO6: [M+H] + Theoretical value: 558.4728; Experimental value: 558.4728.

Claims

1. A method for the synthesis of very long chain glucose amide non-ionic surfactants, characterized in that, The structure of the super-long chain glucose amide nonionic surfactant is as follows, ， In the formula, R1 is CH3 or CH2CH3, and n is 5 or 7; the hydrophobic tail chain raw material is selected from one of erucic acid and nervonic acid, and the hydrophilic head group raw material is selected from a glucose derivative meglumine or glycol amine; Preparation includes the following steps, Step 1: Meglumine or glycol amine is added to a solvent, and a catalyst DMAP is added, and the amine group is mixed and activated at 10-30 °C by high shear stirring for 20-40 min to obtain solution A; erucic acid or nervonic acid is dissolved in a solvent to obtain solution B; Step 2: Solution A and solution B are mixed by high shear stirring, and stirred at 10-30 °C for 8-24 hours, and after the reaction is completed, the organic solvent is removed to obtain a crude product of the super-long chain glucose amide nonionic surfactant; Step 3: The obtained crude product is dissolved in dichloromethane, and acetone is slowly dropped at 15-45 °C for crystallization to obtain the purified super-long chain glucose amide nonionic surfactant; The mass ratio of meglumine or glycol amine to the solvent is 1:(50-60); the mass ratio of meglumine or glycol amine to the catalyst is 1:(0.002-0.003); The molar ratio of erucic acid or nervonic acid to meglumine or glycol amine is 1:(0.8-0.95); the mass ratio of erucic acid or nervonic acid to its solvent is 1:(20-30); The solvent is at least one of methanol, ethanol, ethylene glycol, and propylene glycol; The high shear method in step 1 is to use a high shear mixer to mix at 8000-12000 rpm, 25 °C for 30 min to obtain solution A; In step 2, erucic acid or nervonic acid is dissolved in a solvent, and is mixed by an ultrasonic mixer to obtain solution B; In step 2, solution A and solution B are mixed by a high shear mixer at 8000-12000 rpm until they are fully mixed and uniform; In step 3, the mass ratio of the crude product to dichloromethane is 1:(45-55); the mass ratio of the dropped acetone to dichloromethane is 1:(0.5-0.8).

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