Foam inhibition type surfactant as well as preparation method and application thereof

Abstract

The invention relates to the technical field of surfactants in fine chemical engineering, in particular to a foam inhibition type surfactant as well as a preparation method and application thereof. According to the foam inhibition type surfactant provided by the invention, the ionic surfactant is constructed by taking octadecyl as a lipophilic group and taking carboxylic acid groups, acylamino and quaternary ammonium salt groups as hydrophilic groups, and the ionic surfactant is matched with various hydrophilic groups through the lipophilic group, so that the foam inhibition type surfactant has the advantages that the foam inhibition type surfactant is more stable in foam inhibition; therefore, the foam inhibitor has excellent foam inhibition performance, emulsibility, low-foam performance, foam stability and surface performance. The structural formula of the foam inhibition type surfactant is shown as a formula (I),

Description

Technical Field

[0001] This invention relates to the field of surfactant technology in fine chemicals, specifically to an antifoaming surfactant, its preparation method, and its application. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Defoaming surfactants are a class of surfactants that can inhibit or reduce foam formation, acting in the opposite way to common foaming surfactants. These substances reduce foam formation or accelerate foam collapse by interfering with bubble formation or stabilization mechanisms. Defoaming surfactants retain the wetting, emulsifying, and dispersing properties of surfactants while avoiding the problems caused by excessive foaming, making them suitable for a wide range of applications, such as in industrial cleaning agents like metal cleaners, metal degreasers, and plastic cleaners.

[0004] Currently, antifoaming or low-foaming surfactants are mainly compound products, with few reports on single-chemical-component products, and most are nonionic surfactants. Compared with nonionic surfactants, ionic surfactants have the following advantages: stronger electrolyte compatibility and chemical stability, excellent stability in high-salt and high-electrolyte environments, and less prone to precipitation or inactivation; higher wetting and penetration efficiency, able to quickly adsorb onto surfaces with opposite charges, significantly improving wetting speed; functional diversity, such as low-foaming quaternary ammonium salt surfactants which combine antifoaming, bactericidal, and antistatic functions; and lower raw material costs, making them easier to mass-produce.

[0005] Meanwhile, due to limited research and development of antifoaming or low-foaming surfactants, the variety of these surfactants is limited, their prices are high, and their preparation methods are cumbersome and difficult. Therefore, there is an urgent need to develop ionic surfactants with simple preparation methods and excellent antifoaming or low-foaming effects. Summary of the Invention

[0006] To overcome the above problems, the present invention provides a foam-suppressing surfactant, its preparation method and application.

[0007] To achieve the above technical objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides an antifoaming surfactant having the structural formula shown in formula (I).

[0009]

[0010] A second aspect of the present invention provides a method for preparing the antifoaming surfactant described in the first aspect, comprising the following steps:

[0011] (1) Dissolve N-hydrogenated tallow-1,3-propanediamine in an alcohol solvent, add itaconic acid, and react to obtain intermediate I;

[0012] (2) Add acrylamide to intermediate I and react to obtain intermediate II;

[0013] (3) Add chloroacetic acid to intermediate II and react to obtain the foam-suppressing surfactant;

[0014] The structural formula of intermediate I is shown below:

[0015]

[0016] The structural formula of intermediate II is shown below:

[0017]

[0018] A third aspect of the present invention provides the use of the defoaming surfactant described in the first aspect or the defoaming surfactant prepared by the preparation method described in the second aspect as a defoaming agent.

[0019] A fourth aspect of the present invention provides the application of the antifoaming surfactant described in the first aspect or the antifoaming surfactant prepared by the preparation method described in the second aspect as a low-foaming surfactant.

[0020] A fifth aspect of the present invention provides the use of the antifoaming surfactant described in the first aspect or the antifoaming surfactant prepared by the preparation method described in the second aspect as an emulsifier.

[0021] The beneficial effects of this invention are as follows:

[0022] (1) The defoaming surfactant provided in this invention uses octadecyl groups as lipophilic groups and carboxylic acid groups, amide groups, and quaternary ammonium salt groups as hydrophilic groups to construct an ionic surfactant. This ionic surfactant, through the interaction of lipophilic groups and various hydrophilic groups, makes the defoaming surfactant shown in formula (I) have excellent defoaming performance, emulsifying properties, low foaming properties, foam stabilizing properties, and surface properties. The defoaming surfactant molecule contains two carboxylic acid groups, which can form stronger and more intramolecular or intermolecular hydrogen bonds; in addition, the defoaming surfactant molecule contains quaternary ammonium salt groups, which are more polar; the hydrophilic groups such as carboxylic acid groups, amide groups, and quaternary ammonium salt groups directly cooperate with the amide groups in the pyrrolidone ring to form a hydrophilic structure with multiple polar centers, which enhances the solubility of the molecule in water and the interfacial activity, enhances the orderly arrangement of the molecule at the interface, forms a more stable monolayer film, effectively reduces surface tension, and inhibits the formation and growth of foam, thereby exhibiting excellent defoaming performance and low foaming performance.

[0023] (2) Experimental results show that a very small amount (0.05g) of the pure antifoaming surfactant of formula (Ⅰ) exhibits excellent antifoaming performance (antifoaming value P = 0.96). Compared with the control group sodium dodecylbenzenesulfonate, the initial volume of the foam after shaking and the volume of the foam after 5 minutes are both lower than those of the control group. The time required for the foam volume to become 1 / 2L0 is greater than 3600s, which not only proves that the pure antifoaming surfactant is a low-foaming surfactant but also has good foam stabilizing properties. Surface performance tests on the pure antifoaming surfactant show that it has excellent surface properties. Based on its characteristics, this product is particularly suitable for industrial cleaning agent applications.

[0024] (3) The antifoaming surfactant raw materials provided in this invention are inexpensive, widely available, and have low production costs.

[0025] (4) The foam-suppressing surfactant provided in this invention only requires three steps of mixing and heating to obtain the foam-suppressing surfactant. Pure foam-suppressing surfactant can be obtained by conventional distillation and recrystallization. The overall reaction conditions are mild and do not require reaction under harsh conditions of high temperature and high pressure. The preparation method is simple and easy to prepare on a large scale. Attached Figure Description

[0026] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0027] Figure 1 This describes the preparation route for antifoaming surfactants.

[0028] Figure 2Infrared spectrum of pure antifoaming surfactant;

[0029] Figure 3 The surface tension-log c graph is for pure antifoaming surfactants. Detailed Implementation

[0030] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0031] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0032] A first typical embodiment of the present invention provides a foam-suppressing surfactant, the structural formula of which is shown in formula (I).

[0033]

[0034] A second typical embodiment of the present invention provides a method for preparing the antifoaming surfactant described in the first aspect, comprising the following steps:

[0035] (1) Dissolve N-hydrogenated tallow-1,3-propanediamine in an alcohol solvent, add itaconic acid, and react to obtain intermediate I;

[0036] (2) Add acrylamide to intermediate I and react to obtain intermediate II;

[0037] (3) Add chloroacetic acid to intermediate II and react to obtain the foam-suppressing surfactant;

[0038] The structural formula of intermediate I is shown below:

[0039]

[0040] The structural formula of intermediate II is shown below:

[0041]

[0042] In one or more embodiments, the preparation method further includes purification, in which the alcohol solvent is removed from the mixture after the reaction in step (3), and then recrystallized and purified to obtain a pure antifoaming surfactant.

[0043] Preferably, the solvent used for recrystallization is methanol.

[0044] In one or more embodiments, in step (1), the alcohol solvent is selected from ethanol, isopropanol, and propanol. Under the conditions of this alcohol solvent, the raw material has good solubility, resulting in high reactivity, and the alcohol solvent has a low boiling point, making it easy to purify antifoaming surfactants.

[0045] In one or more embodiments, the molar ratio of N-hydrogenated tallow-1,3-propanediamine, alcohol solvent, itaconic acid, acrylamide, and chloroacetic acid is 1:(9-20):(1.00-1.07):(1.00-1.09):(1.01-1.09). Under these ratio conditions, the reactivity is high and the yield of the antifoaming surfactant is high.

[0046] In one or more embodiments, in step (1), the reaction temperature is 61–82°C and the reaction time is 3–5 h. Under these reaction conditions, the reaction activity is high and the yield of intermediate I is high.

[0047] In one or more embodiments, in step (2), the reaction temperature is 61–82°C and the reaction time is 2–4 h. Under these reaction conditions, the reaction activity is high and the yield of intermediate II is high.

[0048] In one or more embodiments, in step (3), the reaction temperature is 61–82°C and the reaction time is 2–4 h. Under these reaction conditions, the reactivity is high and the yield of the antifoaming surfactant is high.

[0049] In one or more embodiments, the method for preparing the antifoaming surfactant includes the following steps:

[0050] (1) Dissolve N-hydrogenated tallow-1,3-propanediamine in an alcohol solvent, add itaconic acid, mix well, and heat at 61-82℃ for 3-5 hours to obtain intermediate I;

[0051] (2) Add acrylamide to the intermediate, mix well, and heat at 61-82℃ for 2-4 hours to obtain intermediate II;

[0052] (3) Add chloroacetic acid to intermediate II, mix well, and heat at 61-82℃ for 2-4 hours to obtain crude antifoaming surfactant; remove alcohol solvent by atmospheric distillation, and purify by recrystallization with methanol to obtain pure antifoaming surfactant.

[0053] A third typical embodiment of the present invention provides the application of the antifoaming surfactant described in the first aspect or the antifoaming surfactant prepared by the preparation method described in the second aspect as an antifoaming agent.

[0054] A fourth typical embodiment of the present invention provides the application of the antifoaming surfactant described in the first aspect or the antifoaming surfactant prepared by the preparation method described in the second aspect as a low-foaming surfactant.

[0055] A fifth typical embodiment of the present invention provides the application of the antifoaming surfactant described in the first aspect or the antifoaming surfactant prepared by the preparation method described in the second aspect as an emulsifier.

[0056] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0057] Figure 1 The preparation route of the antifoaming surfactant of this invention is described in reference. Figure 1 Synthesize antifoaming surfactants.

[0058] Example 1

[0059] (1) 326.0 g of N-hydrogenated tallow-1,3-propanediamine (1.00 mol) was dispersed in 750.0 g of isopropanol and stirred at 75.0 °C to dissolve. Then, 134.0 g of itaconic acid (1.03 mol) was added and the mixture was stirred at 75.0 °C for 4 h to obtain reaction intermediate I.

[0060] (2) Add 74.6 g of acrylamide (1.05 mol) to the reaction system of step (1), and keep the mixture at 75.0 °C and stir for 3 h to obtain reaction intermediate II;

[0061] (3) Add 99.2 g of chloroacetic acid (1.05 mol) to the reaction system of step (2), keep warm and stir at 75.0 °C for 3 h to obtain crude antifoaming surfactant. Remove the solvent isopropanol by distillation under normal pressure, and purify by recrystallization with methanol 3 times to obtain pure antifoaming surfactant.

[0062] Figure 2 To obtain the FTIR spectrum of the pure antifoaming surfactant in this embodiment, Figure 2 3357cm -1 Peak 1 is the stretching vibration peak of OH, at 3184 cm⁻¹. -1 Peak 2 is the NH stretching vibration peak, at 2918 cm⁻¹. -1 Peak 3 is the absorption peak of the asymmetric stretching vibration of the methylene group, at 2850 cm⁻¹. -1 Peak 4 is the absorption peak of the symmetric stretching vibration of the methylene group, at 1683 cm⁻¹. -1Peak 5 is the absorption peak of the stretching vibration of C=O, at 1625 cm⁻¹. -1 Peak 6 is the absorption peak of the asymmetric stretching vibration of CO, at 1469 cm⁻¹. -1 Peak 7 is the absorption peak of the asymmetric bending vibration of the methylene group, at 1392 cm⁻¹. -1 Peak 8 is the stretching vibration absorption peak of CN, at 943 cm⁻¹. -1 Peak 9 is the absorption peak of the out-of-plane bending vibration of the methylene group, at 721 cm⁻¹. -1 (peak 10) represents the in-plane rocking vibration of the methylene group.

[0063] Example 2

[0064] (1) 326.0 g of N-hydrogenated tallow-1,3-propanediamine (1.00 mol) was dispersed in 750.0 g of anhydrous ethanol and stirred at 75.0 °C to dissolve. Then, 134.0 g of itaconic acid (1.03 mol) was added and the mixture was stirred at 75.0 °C for 4 h to obtain reaction intermediate I.

[0065] (2) Add 74.6 g of acrylamide (1.05 mol) to the reaction system of step (1), and keep the mixture at 75.0 °C and stir for 3 h to obtain reaction intermediate II;

[0066] (3) Add 99.2 g of chloroacetic acid (1.05 mol) to the reaction system in step (2), and keep it at 75.0 °C and stir for 3 h to obtain crude antifoaming surfactant. Remove the solvent ethanol by distillation under normal pressure, and purify it three times by recrystallization with methanol to obtain pure antifoaming surfactant.

[0067] Example 3

[0068] The defoaming performance of the pure defoaming surfactant prepared in Example 1 was tested. The specific test methods included:

[0069] Take 10 mL of 0.5% sodium dodecylbenzenesulfonate (LBS) aqueous solution and a certain mass of sample into a 100 mL stoppered graduated cylinder, shake vigorously twenty times, measure the foam volume, and calculate the foam suppression value (P).

[0070] P = (V0 - V1) / V0;

[0071] Where V0 is the foam volume (mL) during the blank experiment, and V1 is the foam volume (mL) when the sample is added.

[0072] The defoaming properties of the pure defoaming surfactant prepared in Example 1 are shown in Table 1.

[0073] Table 1 Results of foam suppression performance

[0074]

[0075] As can be seen from Table 1, compared with OP-10, the antifoaming surfactant shown in Formula (I) has excellent antifoaming properties. Experimental results show that a very small amount (0.05 g) of pure antifoaming surfactant shown in Formula (I) has excellent antifoaming properties (antifoaming value P is 0.96).

[0076] Example 4

[0077] The emulsifying properties of the pure antifoaming surfactant prepared in Example 1 were tested. The specific test methods included:

[0078] The pure antifoaming surfactant prepared in Example 1 was dissolved in water to obtain a pure antifoaming surfactant aqueous solution. The pH of the pure antifoaming surfactant aqueous solution was adjusted to 12 using NaOH aqueous solution (2 mol / L). The mass fraction of the pure antifoaming surfactant in the pure antifoaming surfactant aqueous solution was 0.1%. 20 mL of the pure antifoaming surfactant aqueous solution and 20 mL of liquid paraffin were placed in a 100 mL stoppered graduated cylinder, shaken vigorously five times, and allowed to stand for 1 min. This process was repeated five times.

[0079] Results: The test showed that the pure antifoaming surfactant separated 10 mL of water in 494 s. Using OP-10 as a control group, the separation time was 684 s. This demonstrates that the pure antifoaming surfactant provided by this invention has excellent emulsifying properties.

[0080] Example 5

[0081] The foaming and foam-stabilizing properties of the pure antifoaming surfactant prepared in Example 1 were tested. The specific test methods included:

[0082] The pure antifoaming surfactant prepared in Example 1 was dissolved in water to obtain an aqueous solution of the pure antifoaming surfactant. The pH of the aqueous solution was adjusted to 12 using NaOH aqueous solution (2 mol / L), resulting in a concentration of 0.001 mol / L for the pure antifoaming surfactant. 20 mL of the aqueous solution was placed in a 100 mL stoppered graduated cylinder and kept at 25°C for 10 min. The solution was then vigorously shaken 20 times. The following measurements were taken: the initial volume of foam (L0, mL), the volume of foam after 5 min (L5, mL), and the time required for the foam volume to become 1 / 2L0 (t). 1 / 2 (Unit: s). Sodium dodecylbenzenesulfonate (0.001 mol / L) was used as the control group.

[0083] The foaming and foam stabilizing performance tests are shown in Table 2. As can be seen from Table 2, compared with the control group sodium dodecylbenzenesulfonate, the L0 of the pure foam suppressant surfactant is 3 mL, and the foam volume after 5 min is also 3 mL. The time required for the foam volume to become 1 / 2 L0 is greater than 3600 s. This not only proves that the pure foam suppressant surfactant is a low-foaming surfactant, but also has good foam stabilizing performance.

[0084] Table 2 Foaming and Foam Stability

[0085]

[0086] Example 6

[0087] The surface properties of the pure antifoaming surfactant prepared in Example 1 were tested. The specific test methods included:

[0088] The surface tension-log c plot was obtained by measuring the surface tension (γ) of the pure antifoaming surfactant (see...). Figure 3 The surface performance parameters were calculated, and the results are shown in Table 3.

[0089] Table 3 Surface property parameters

[0090] product <![CDATA[CMC(mol·L -1 )]]> <![CDATA[γ CMC (mN·m -1 )]]> <![CDATA[C 20 (mol·L -1 )]]> <![CDATA[pC 20 ]]> <![CDATA[CMC / C 20 ]]> Pure product (1) <![CDATA[2.19×10 -4 ]]> 41.2 <![CDATA[3.07×10 -5 ]]> 4.51 7.13

[0091] As can be seen from Table 3, its critical micelle concentration (CMC) is 2.19 × 10⁻⁶. -4 The concentration of mol / L indicates that the pure antifoaming surfactant in this invention has excellent surface properties.

[0092] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A foam-suppressing surfactant, characterized in that, Its structural formula is shown in equation (Ⅰ).

2. The method for preparing the antifoaming surfactant according to claim 1, characterized in that, Includes the following steps: (1) Dissolve N-hydrogenated tallow-1,3-propanediamine in an alcohol solvent, add itaconic acid, and react to obtain intermediate I; (2) Add acrylamide to intermediate I and react to obtain intermediate II; (3) Add chloroacetic acid to intermediate II and react to obtain the foam-suppressing surfactant; The structural formula of intermediate I is shown below: The structural formula of intermediate II is shown below:

3. The preparation method according to claim 2, characterized in that, The preparation method also includes purification, in which the alcohol solvent is removed from the mixture after the reaction in step (3), and then recrystallized and purified to obtain a pure antifoaming surfactant. Preferably, the solvent used for recrystallization is methanol.

4. The preparation method according to claim 2, characterized in that, In step (1), the alcohol solvent is selected from ethanol, isopropanol and propanol.

5. The preparation method according to claim 2, characterized in that, The molar ratio of N-hydrogenated tallow-1,3-propanediamine, alcohol solvent, itaconic acid, acrylamide, and chloroacetic acid is 1:(9-20):(1.00-1.07):(1.00-1.09):(1.01-1.09).

6. The preparation method according to claim 2, characterized in that, In step (1), the reaction temperature is 61-82℃ and the reaction time is 3-5h.

7. The preparation method according to claim 2, characterized in that, In step (2), the reaction temperature is 61-82℃ and the reaction time is 2-4h.

8. The preparation method according to claim 2, characterized in that, In step (3), the reaction temperature is 61-82℃ and the reaction time is 2-4h.

9. The use of the antifoaming surfactant according to claim 1 or the antifoaming surfactant prepared by any one of claims 2 to 8 as an antifoaming agent.

10. The use of the antifoaming surfactant according to claim 1 or the antifoaming surfactant prepared by any one of claims 2 to 8 as a low-foaming surfactant or emulsifier.

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