Amino acid surfactant mixture and method of making and use thereof

Abstract

The application relates to an amino acid type surfactant mixture and a preparation method and application thereof, and belongs to the technical field of surfactants. The preparation method comprises the following steps: hydrogenated palm oil is heated and melted under nitrogen protection, amino acid is added, and stirring, mixing and uniformity are carried out; base and a solubilizing agent are added, and reaction is carried out at 125-130 DEG C for 2-3 hours, so that an amino acid type surfactant mixture containing N-acyl amino acid salt and diglyceride is obtained. The amino acid type surfactant mixture is synthesized by using a one-step method, the process is simple, the reaction condition is mild, the obtained product has an emulsifying and dispersing system, an emulsifying and dispersing agent does not need to be additionally added, the amino acid type surfactant mixture has good surface activity and biodegradability. When the amino acid type surfactant mixture is applied to textile softening agents, the softness and smoothness of fabrics can be obviously improved, the whiteness of the fabrics is not affected, the anti-yellowing performance is excellent, and the amino acid type surfactant mixture is suitable for soft finishing of cotton, hemp, silk, wool and various synthetic fibers.

Description

Technical Field

[0001] This invention relates to the field of surfactant technology, specifically to an amino acid-type surfactant mixture, its preparation method, and its application. Background Technology

[0002] Textile softeners are indispensable auxiliaries in the finishing process of textile printing and dyeing. Their function is to improve the hand feel of fabrics, making them soft, full, and smooth. Currently, the textile softeners widely used in the market mainly include quaternary ammonium salt softeners, silicone softeners, and fatty acid softeners. Among them, quaternary ammonium salt softeners, while having good softening effects, have poor biodegradability, thus burdening the environment. Silicone softeners, although having excellent softening effects, have the biggest drawback of being expensive, resulting in high costs, and are prone to oil leaching during use, thus polluting the fabric. Fatty acid softeners are mainly synthesized by reacting stearic acid with diethylenetriamine or hydroxyethyl ethylenediamine. Because the primary and secondary amines remaining after the reaction of stearic acid and diethylenetriamine can cause fiber yellowing under high temperatures, thus affecting the quality of the fabric. Furthermore, prolonged exposure to hydroxyethyl ethylenediamine can have adverse effects on fetal development.

[0003] Amino acid surfactants are a class of green surfactants with amino acids as hydrophilic groups, exhibiting good biodegradability, low irritation, and excellent surface activity. N-acyl amino acid surfactants, in particular, not only possess excellent surface activity but also superior safety and biodegradability. However, current methods for preparing surfactants from amino acids and natural oils mostly employ a two-step process of acyl chloride-amidation of fatty acids and amino acids, which is complex, requires harsh reaction conditions, and is costly. Furthermore, the application of amino acid-based surfactants in textile softeners is still insufficient.

[0004] In existing technologies, such as CN115703716A, a method for producing amino acid-based surfactants is disclosed. However, this method mainly focuses on the preparation of the surfactant itself and does not address its specific application in textile softeners. Another example is CN112812031A, a method for preparing N-acyl amino acid-type surfactants disclosed by Changzhou University. This method involves reacting oils, amino acid donors, alkalis, and water under high temperature and pressure. However, this method requires high reaction temperatures (160–200℃) and high pressures (3–5 MPa), placing high demands on equipment and consuming a large amount of energy.

[0005] Therefore, developing an amino acid-based surfactant with simple processing, mild reaction conditions, and excellent softening properties, and its application as a textile softener, is of great practical significance. Summary of the Invention

[0006] To address the problems in existing technologies, the present invention aims to provide an amino acid-based surfactant mixture, its preparation method, and its applications. This method uses hydrogenated palm oil and amino acids as raw materials to synthesize an amino acid-based surfactant mixture in a one-step process. The process is simple and the reaction conditions are mild. The resulting mixture does not require the addition of additional emulsifying and dispersing agents and exhibits excellent softening properties, low yellowing, good biodegradability, and environmental friendliness.

[0007] The method for preparing an amino acid-type surfactant mixture according to the present invention includes the following steps: Step S1: Heat the hydrogenated palm oil to 85-95°C under nitrogen protection until it is completely melted, add amino acids, and stir until it is evenly mixed while in the molten state; Step S2: Add alkali and solubilizer to the mixture obtained in step S1, and react at 125-130°C for 2-3 hours to obtain the amino acid-type surfactant mixture.

[0008] Preferably, in step S1, the stirring time in the molten state after adding amino acids is at least 1 hour.

[0009] Preferably, the molar ratio of hydrogenated palm oil to amino acids is 1:1 to 1.5.

[0010] Preferably, the alkali in step S2 is one or more of sodium hydroxide and potassium hydroxide, and the amount of alkali used is 1 to 1.1 times the molar amount of amino acids; the amount of solubilizer used is 0.5 times the molar amount of amino acids.

[0011] Preferably, the amino acid is selected from one or more of glycine, sarcosine, L-alanine, glutamic acid, aspartic acid, and methionine; The solubilizer is selected from one or more of glycerol, ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol.

[0012] The amino acid-type surfactant mixture provided by the present invention is prepared by the aforementioned preparation method, and the mixture comprises N-acyl amino acid salt and diglyceride.

[0013] The textile softener provided by the present invention comprises the aforementioned amino acid-type surfactant mixture.

[0014] Preferably, by weight, it comprises the following components: 10-20 parts of an amino acid-type surfactant mixture and 80-90 parts of water.

[0015] Preferably, it further comprises one or more of the following: 0.1 to 5 parts by weight of antibacterial agent, 0.1 to 3 parts by weight of preservative, and 0.1 to 2 parts by weight of defoamer.

[0016] The application of the amino acid-type surfactant mixture prepared by the method provided in this invention in the finishing process of textile softening.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention uses hydrogenated palm oil and amino acids as raw materials. Hydrogenated palm oil is a natural renewable resource, and amino acids are a biomass resource. The raw materials are widely available and renewable. Hydrogenated palm oil has high stability after hydrogenation and is not easily oxidized or deteriorated. The resulting product is completely biodegradable and does not pollute the environment.

[0018] (2) The present invention adopts a one-step synthesis method, which avoids the complex process of the traditional two-step acyl chloride-amidation method. The reaction temperature is significantly lower than that of the prior art (160-200℃), the energy consumption is low, the equipment requirements are low, and it is suitable for industrial production.

[0019] (3) The amino acid-type surfactant prepared in this invention has good surface activity, and its molecular structure contains hydrophilic amino acid groups and long-chain hydrophobic groups of hydrogenated palm oil. When applied to textile softeners, it can effectively reduce the coefficient of friction between fibers, making the fabric soft and smooth. All the amino groups in the mixture that are prone to yellowing are acylated, and there are no unsaturated double bonds, thereby significantly reducing or avoiding yellowing of fibers under high temperature, resulting in good whiteness of the fabric.

[0020] (4) During the preparation of the amino acid surfactant mixture, as shown below, diglyceride surfactant is generated simultaneously, which can play an emulsifying and dispersing role in the system. Therefore, the mixture of the present invention forms a stable system with its own emulsifying and dispersing agent, and there is no need to add additional emulsifying and dispersing agent, which is beneficial to simplify the operation process during use.

[0021] Detailed Implementation

[0022] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0023] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and claims of this invention are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented, for example, in orders other than those described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0024] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0025] The technical solutions of the present invention and how they solve the above-mentioned technical problems will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will be described below.

[0026] The main components of the hydrogenated palm oil used in the examples are glyceryl tristearate and glyceryl tripalmitate. Based on an average molecular weight of about 850, 100g of hydrogenated palm oil is equivalent to about 0.12 mol.

[0027] Example 1

[0028] 100g (approximately 0.12 mol) of hydrogenated palm oil was placed in a reaction vessel and heated to 90°C under nitrogen protection until completely melted. 9g (0.12 mol) of glycine was added, and the mixture was stirred for 1 hour in the molten state until homogeneous. 6.7g (0.12 mol) of potassium hydroxide and 5.5g (0.06 mol) of glycerol were added to the above system, and the mixture was reacted at 125°C for 3 hours to obtain a mixture of N-acyl amino acid salt surfactants.

[0029] Example 2

[0030] 100g (approximately 0.12 mol) of hydrogenated palm oil was placed in a reaction vessel and heated to 90°C under nitrogen protection until completely melted. 10.7g (0.12 mol) of L-alanine was added, and the mixture was stirred in the molten state for 1 hour until homogeneous. 6.7g (0.12 mol) of potassium hydroxide and 5.5g (0.06 mol) of glycerol were added to the above system, and the mixture was reacted at 130°C for 2.5 hours to obtain a mixture of N-acyl amino acid salt surfactants.

[0031] Example 3

[0032] 100g (approximately 0.12 mol) of hydrogenated palm oil was placed in a reaction vessel and heated to 85°C under nitrogen protection until completely melted. 9g (0.12 mol) of glycine was added, and the mixture was stirred for 1 hour in the molten state until homogeneous. 5.2g (0.12 mol) of sodium hydroxide and 5.5g (0.06 mol) of glycerol were added to the above system, and the mixture was reacted at 125°C for 3 hours to obtain a mixture of N-acyl amino acid salt surfactants.

[0033] Example 4

[0034] 100g (approximately 0.12 mol) of hydrogenated palm oil was placed in a reaction vessel and heated to 95°C under nitrogen protection until completely melted. 9g (0.12 mol) of glycine was added, and the mixture was stirred for 1 hour in the molten state until homogeneous. 6.7g (0.12 mol) of potassium hydroxide and 3.7g (0.06 mol) of ethylene glycol were added to the above system, and the mixture was reacted at 130°C for 2 hours to obtain a mixture of N-acyl amino acid salt surfactants.

[0035] Example 5

[0036] 100g (approximately 0.12 mol) of hydrogenated palm oil was placed in a reaction vessel and heated to 90°C under nitrogen protection until completely melted. 9g (0.12 mol) of glycine was added, and the mixture was stirred for 1 hour in the molten state until homogeneous. 3.4g (0.06 mol) of potassium hydroxide, 2.6g (0.06 mol) of sodium hydroxide, and 5.5g (0.06 mol) of glycerol were added to the above system, and the mixture was reacted at 125°C for 3 hours to obtain a mixture of N-acyl amino acid salt surfactants.

[0037] Comparative Example 1 100 g (approximately 0.12 mol) of hydrogenated palm oil was placed in a reaction vessel and heated to 90°C under nitrogen protection until completely melted. 18 g (0.24 mol) of glycine was added, and the mixture was stirred for 1 hour in the molten state until homogeneous. Then, 13.4 g (0.24 mol) of potassium hydroxide and 3.7 g (0.06 mol) of ethylene glycol were added to the above system, and the mixture was reacted at 130°C for 3 hours to obtain a mixture of N-acyl amino acid salt surfactants. In this comparative example, the molar ratio of amino acid to hydrogenated palm oil exceeded 1.5:1.

[0038] Comparative Example 2 Referring to the preparation method of commercially available mainstream fabric softeners: stearic acid and diethylenetriamine were added to a reaction vessel at a molar ratio of 2:1 and reacted at 160°C for 4 hours under nitrogen protection to obtain amide-amine fabric softener products.

[0039] The products obtained in Examples 1-5 and Comparative Examples 1 and 2 were diluted with deionized water to prepare emulsions with a mass concentration of 10%. The emulsions were allowed to stand at room temperature (25°C) for 24 hours to observe their stability. The results are shown in Table 1.

[0040] Table 1. Emulsion stability of the examples and comparative samples

[0041] The prepared emulsion was applied to softening cotton knitwear. Finishing process: softener dosage was 3% of fabric weight, liquor ratio 1:10, working solution temperature 45℃, immersion treatment for 15 minutes, and drying at 170℃. After finishing, the fabric samples were allowed to rehydrate under standard atmospheric conditions for 3 hours, and whiteness and hand feel were tested. Whiteness was measured using a whiteness meter, reflecting the degree of yellowing of the fabric. Hand feel was evaluated by a panel of 5 professionals, each scoring from 1 to 10 (1 being the worst, 10 the best). The sum of the 5 scores was the hand feel score (maximum 50 points), with higher scores indicating better hand feel. Results are shown in Table 2.

[0042] Table 2 Performance of softeners applied to cotton knitwear after softening finishing in both examples and comparative samples.

[0043] As shown in Table 1, the emulsion stability of the softener mixtures prepared in the embodiments of the present invention is superior to that of Comparative Example 1 and Comparative Example 2, which uses commercially available mainstream softeners. This is because the products of the embodiments contain diglycerides generated in the reaction, which can play an emulsifying and dispersing role. The system has its own emulsifying and dispersing ability, and no additional emulsifying and dispersing agent needs to be added. In contrast, in Comparative Example 1, the amount of amino acids exceeds the preferred molar ratio, resulting in a decrease in emulsifying and dispersing ability and causing stratification.

[0044] As shown in Table 2, the whiteness of the fabrics treated in Examples 1 to 5 was significantly higher than that in Comparative Example 2, indicating that the amino acid-based surfactant mixture of the present invention has good anti-yellowing properties and the color of the treated fabrics is minimally affected. The hand feel score was also at a high level, exhibiting excellent softness and smoothness. Although Comparative Example 1 had a comparable hand feel, its emulsion stability was poor, which is not conducive to practical application.

[0045] In summary, the amino acid-based surfactant mixture prepared according to this invention, when used as a textile softener, eliminates the need for additional emulsifiers and dispersants, exhibits good emulsion stability, and results in a soft, smooth hand feel in the finished fabric with virtually no yellowing, significantly improving fabric quality and added value. This softener is suitable for softening various fabrics, including cotton, linen, silk, wool, and synthetic fibers, and has broad application prospects.

[0046] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

[0047] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0048] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A method for preparing a mixture of amino acid-based surfactants, characterized in that, Includes the following steps: Step S1: Heat the hydrogenated palm oil to 85-95°C under nitrogen protection until it is completely melted, add amino acids, and stir until uniformly mixed in the molten state; the molar ratio of hydrogenated palm oil to amino acids is 1:1-1.

5. Step S2: Add alkali and solubilizer to the mixture obtained in step S1, and react at 125-130°C for 2-3 hours to obtain the amino acid-type surfactant mixture.

2. The preparation method according to claim 1, characterized in that, In step S1, the time for stirring in the molten state after adding amino acids is at least 1 hour.

3. The preparation method according to claim 1, characterized in that, The alkali used in step S2 is one or more of sodium hydroxide and potassium hydroxide, and the amount of alkali used is 1 to 1.1 times the molar amount of amino acids; the amount of solubilizer used is 0.5 times the molar amount of amino acids.

4. The preparation method according to claim 1, characterized in that, The amino acid is selected from one or more of glycine, sarcosine, L-alanine, glutamic acid, aspartic acid, and methionine. The solubilizer is selected from one or more of glycerol, ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol.

5. A mixture of amino acid-type surfactants, characterized in that, The mixture is prepared by the preparation method according to any one of claims 1 to 4, wherein the mixture comprises an N-acyl amino acid salt and a diglyceride.

6. The application of an amino acid-type surfactant mixture prepared by any one of claims 1 to 4 in the finishing process of textile softening.

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