A biomass-based surfactant-type thickener and preparation method thereof

Abstract

The present invention discloses a biomass-based surfactant-type thickener and its preparation method. Its structural formula is shown in Formula (A). The present invention also provides a thickening (viscosification) system comprising the compound shown in Formula (A), an inorganic salt, and water. The present invention produces a novel biomass-based surfactant-type thickener. By adjusting the mass ratio of the biomass-based surfactant-type thickener to the inorganic salt and the concentration of the inorganic salt in the system, the viscosity of the system is significantly increased. The biomass-based surfactant-type thickener is derived from biomass and is easily degradable, making it an environmentally friendly thickener. #imgabs0#

Description

Technical Field

[0001] The present invention belongs to the field of surfactant science and application technology, and particularly relates to a biomass-based surfactant thickener and a preparation method thereof. Background Art

[0002] Thickeners are a new type of functional material that has rapidly developed in recent years. They are primarily used to increase the viscosity or consistency of products. They feature low dosage, significant thickening, and ease of use. They are widely used in industries such as pharmaceuticals, printing and dyeing, coatings, cosmetics, food additives, oil production, and papermaking.

[0003] Natural thickeners are mostly derived from polysaccharide-containing mucilages such as starch, gum arabic, guar gum, carrageenan, pectin, agar, and alginic acid. Some are derived from protein-containing plants and animals, such as gelatin, casein, and sodium hydroxybutyrate. Others are derived from microorganisms, such as xanthan gum. Synthetic thickeners include sodium carboxymethylcellulose (CMC), propylene glycol alginate, cellulose glycolate, sodium polyacrylate, sodium starch glycolate, sodium starch phosphate, methylcellulose, and sodium polyacrylate.

[0004] Biomass-based surfactants utilize raw materials readily available in biomass, making them inexpensive and environmentally friendly. Using sorbitol, a biomass-derived raw material, as a raw material, these surfactants can be synthesized and prepared using a simple method. However, the use of biomass-based surfactants as thickeners has rarely been reported. Summary of the Invention

[0005] One of the objects of the present invention is to provide a compound represented by formula (A):

[0006]

[0007] The compound represented by the above formula (A) is prepared by a method comprising the following steps: reacting sorbitol bromide represented by formula 2 with N,N-dimethylhexadecylamine to obtain:

[0008]

[0009] In the above method, the molar ratio of brominated sorbitol shown in Formula 2 to N,N-dimethylhexadecylamine can be 1:2.0-2.5, specifically 1:2.1;

[0010] The reaction temperature can be 40-80°C, and the optimal temperature is 45°C;

[0011] The reaction time can be 6-48h, optimally 12h;

[0012] The solvent of the reaction can be anhydrous methanol, anhydrous ethanol, acetonitrile, etc.; specifically, it can be anhydrous methanol;

[0013] The preparation method of brominated sorbitol shown in Formula 2 is described in Chinese Patent No. 201710041387.9.

[0014] The use of the compound represented by the above formula (A) in the preparation of thickening (tackifying) agents also falls within the scope of protection of the present invention.

[0015] The present invention also provides a thickening (viscosity-increasing) system.

[0016] The thickening (viscosity increasing) system provided by the present invention comprises a compound represented by formula (A), an inorganic salt and water.

[0017] In the thickening (viscosifying) system, the mass concentration of the compound represented by formula (A) can be 0.65wt%-3.28wt%; the mass concentration of the inorganic salt can be 0-3%wt, and the endpoint value 0 is not desirable;

[0018] Specifically, the mass concentration of the compound represented by formula (A) is 2.59 wt %, and the mass concentration of the inorganic salt is 0.3-2.0 wt %, specifically 0.6-1.6 wt %;

[0019] Alternatively, the mass concentration of the inorganic salt is 1.2 wt %, and the mass concentration of the compound represented by formula (A) is 0.65 wt % to 3.28 wt %;

[0020] The inorganic salt can be selected from at least one of sodium chloride, magnesium chloride, ammonium chloride, sodium bromide, potassium bromide, potassium chloride, magnesium chloride, copper chloride, zinc chloride, sodium sulfate, sodium acetate and ferric chloride.

[0021] Specifically, the mass concentration of the compound represented by formula (A) is greater than or equal to 2.59 wt% (2.59 wt%-3.28 wt%), the mass concentration of the inorganic salt is 1.2 wt%, and the obtained system is a gel system.

[0022] The thickening (viscosification) system is prepared by a method comprising the following steps:

[0023] The compound represented by formula (A) is dissolved in water, heated to dissolve, an inorganic salt is added to the resulting solution, stirred evenly, and cooled to room temperature to obtain a thickening (viscosity-enhancing) system.

[0024] The present invention has prepared a novel biomass-based surfactant-type thickener. By adjusting the mass ratio of the biomass-based surfactant-type thickener and the concentration of the inorganic salt in the system, the viscosity of the system is significantly increased, and the obtained thickening system has certain shear resistance and viscoelasticity. The biomass-based surfactant-type thickener is derived from biomass, is used in small amounts, is easily degraded, and is an environmentally friendly thickener. This type of surfactant can form an aqueous thickening system with a variety of cheap inorganic salts at a relatively low concentration, and is used in small amounts, making it a green, efficient, and environmentally friendly thickening system. As a thickener, this surfactant is expected to be applied in the fields of water-based coatings, cosmetics, daily chemical products, wetting, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 2 is a photograph of the solution obtained in the comparative example of the present invention.

[0026] Figure 2 This is a photograph of the gel obtained in Example 3 of the present invention.

[0027] Figure 3 This is the effect of the amount of NaCl added on the solution viscosity in Example 5 of the present invention.

[0028] Figure 4 This is the effect of the addition amount of the compound represented by formula (A) in Example 6 of the present invention on the solution viscosity.

[0029] Figure 5 The figure shows a comparison of the shear resistance of the viscosity-enhancing solutions prepared with different types of inorganic salts in Example 7 of the present invention.

[0030] Figure 6 The modulus of the gel system obtained in Example 8 of the present invention changes with shear rate. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below in conjunction with specific embodiments. The examples provided are only for illustrating the present invention and are not intended to limit the scope of the present invention. The examples provided below can serve as a guide for further improvements by those skilled in the art and are not intended to limit the present invention in any way.

[0032] Unless otherwise specified, the experimental methods in the following examples are conventional methods and were performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials and reagents used in the following examples, unless otherwise specified, were all commercially available.

[0033] Example 1. Preparation of the compound represented by formula (A)

[0034] 12.0 g (3.89 mmol) of bromosorbitol represented by Formula 2, 22.05 g (8.18 mmol) of N,N-dimethylhexadecylamine, and 60 mL of anhydrous methanol were added to a reaction vessel, heated to 45°C, and stirred for 24 hours. After the reaction, the reaction solution was concentrated under reduced pressure and recrystallized from acetone / ethanol (v / v = 2:1) to obtain the compound represented by Formula (A) as a white solid in an 86% yield. The structural verification data are as follows: 1 H-NMR (400MHz, DMSO): δ=0.79-0.88(t,6H,-CH3),1.13-1.37(m,24H),2.64-2.86(s,12H),2.89-3.07(m,4H),3.28-3.36(m,4H); MALDI-TOF-MS(M+Na) + :Calcd.For C 42 H 90 Br2N2O4:846.9.Found:847(M+H),869(M+Na); verified that the structure is correct.

[0035] Comparative Example

[0036] 30 mg of the compound represented by formula (A) prepared in Example 1 was dissolved in 1.5 ml of water at 60° C., and 20 mg of NaCl was added. The resulting solution had no obvious viscosity at 60° C. Figure 1 shown.

[0037] Example 2. Preparation of viscosity-increasing (thickening) system

[0038] 40 mg of the compound of formula (A) prepared in Example 1 was weighed and dissolved in 1.5 ml of secondary water, heated at 60° to dissolve, 10 mg of NaCl was added to the solution, slowly stirred and cooled to room temperature to obtain a solution with increased viscosity.

[0039] Example 3. Preparation of gel

[0040] 40 mg of the compound of formula (A) obtained in Example 1 was dissolved in 1.5 ml of water at 60° C., 20 mg of NaCl was added, and the solution was cooled to room temperature. The viscosity of the obtained solution increased significantly (viscosity value 3343 mPa·s) and formed a gel after standing. Figure 2 shown.

[0041] Example 4. Preparation of gel

[0042] 40 mg of the compound of formula (A) prepared in Example 1 was weighed and dissolved in 1.5 ml of secondary water, heated to 60° C. to dissolve, 20 mg (1.2% wt) of CuCl 2 was added to the solution, slowly stirred evenly, and cooled to room temperature to obtain a gel system.

[0043] Example 5: Investigating the effect of the amount of NaCl on solution viscosity

[0044] 40 mg of the compound of formula (A) obtained in Example 1 was dissolved in 1.5 ml of water (2.59 wt%) at 60°C, and different amounts of NaCl were added. The solution was cooled to room temperature and the viscosity of the resulting solution was measured. Figure 3 As shown. Figure 3 It can be seen that the dosage of the compound represented by formula (A) is 31.5 mmol / L or 2.59 wt%. As the NaCl concentration increases, the solution viscosity increases. When the NaCl concentration is 1.2 wt%, it forms a gel. When the NaCl concentration increases to 1.9 wt%, the viscosity drops sharply.

[0045] Example 6: Investigating the effect of the amount of the compound represented by formula (A) on the viscosity of the solution

[0046] Aqueous solutions of the compound represented by formula (A) with different concentrations were prepared at 60°C, 1.2 wt% NaCl was added, and the solution was cooled to room temperature. The viscosity of the resulting solution was measured. Figure 4 As shown in Table 1. Figure 4 It can be seen that when the NaCl content is 1.2 wt %, the solution viscosity increases with the increase in the concentration of the compound represented by formula (A), and the viscosity-increasing effect of the compound represented by formula (A) at a lower concentration is also significant.

[0047] Table 1. Effect of surfactant dosage on solution viscosity

[0048]

[0049]

[0050] Example 7: Comparison of shear resistance of thickening solutions prepared from different types of inorganic salts

[0051] A 2.59 wt% aqueous solution of compound S represented by formula (A) was prepared at 60°C, and different inorganic salts were added, with the mass concentration of the inorganic salts being 1.2 wt%. The solution was cooled to room temperature, and the viscosity of the resulting solution was examined as a function of shear rate. The results are shown in FIG. Figure 5 As shown. Figure 5 It can be seen that when 1.2 wt % NaCl is added, the thickening effect of the solution is the best, and the viscosity of the thickened solution has a certain shear resistance.

[0052] Example 8: Viscoelasticity of the gel system

[0053] A 2.59 wt% aqueous solution of the compound represented by formula (A) was prepared at 60°C, 1.2 wt% NaCl was added, and the solution was cooled to room temperature. The change in the modulus of the resulting solution with shear rate was investigated. The results are shown in Figure 6.

[0054] Depend on Figure 6 It can be seen that the prepared gel system has a certain viscoelasticity.

[0055] The present invention has been described in detail above. For those skilled in the art, without departing from the purpose and scope of the present invention, and without the need to carry out unnecessary experimental conditions, the present invention can be implemented in a wide range under equivalent parameters, concentrations and conditions. Although the present invention provides specific embodiments, it should be understood that further improvements can be made to the present invention. In short, according to the principles of the present invention, this application is intended to include any changes, uses or improvements to the present invention, including changes that depart from the disclosed scope in this application and are made using conventional techniques known in the art.

Claims

1. A thickening system comprising a compound represented by formula (A), an inorganic salt and water, In the thickening system, the inorganic salt is NaCl; The mass concentration of the compound represented by formula (A) is 2.59 wt %, and the mass concentration of the inorganic salt is 0.6-1.9 wt %; Alternatively, the mass concentration of the inorganic salt is 1.2 wt %, and the mass concentration of the compound represented by formula (A) is 0.65 wt % to 3.28 wt %.

2. The thickening system according to claim 1, characterized in that In the thickening system, the amount of water is 1.5 ml, the amount of the compound represented by formula (A) is 30-50 mg, and the amount of NaCl is 20 mg.

3. The thickening system according to claim 1, characterized in that The mass concentration of the inorganic salt is 1.2 wt %, the mass concentration of the compound represented by formula (A) is 2.59 wt %-3.28 wt %, and the obtained system is a gel system.

4. A method for preparing the thickening system according to any one of claims 1 to 3, comprising the steps of dissolving the compound represented by formula (A) in water, heating to dissolve, adding an inorganic salt to the resulting solution, stirring uniformly, and cooling to room temperature to obtain the thickening system.

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