A chitosan-organic acid supramolecular ionic salt and its preparation method

Abstract

This invention discloses a chitosan-organic acid supramolecular ionic salt and its preparation method, belonging to the supramolecular field. The invention involves mixing chitosan with an organic acid (one or more of maleic acid, sorbic acid, ferulic acid, caffeic acid, cinnamic acid, and fumaric acid) and a solvent, followed by drying to obtain the chitosan-organic acid supramolecular ionic salt. The chitosan-organic acid supramolecular ionic salt prepared by this invention can improve the water solubility of chitosan and improve severely damaged hair, offering multiple functions such as repair and smoothing, making it suitable for hair care products. Furthermore, the preparation method is simple, requiring no catalyst or high temperature and pressure, making it suitable for industrial use.

Description

Technical Field

[0001] This invention relates to a chitosan-organic acid supramolecular ionic salt and its preparation method, belonging to the field of supramolecular technology. Background Technology

[0002] Chitosan, a natural linear polyaminopolysaccharide, is a product obtained from the deacetylation of chitin. It is widely found in the shells of crustaceans such as shrimp and crabs, as well as in the cell walls of fungi. Its chemical name is (1,4)-2-amino-2-deoxy-β-D-glucan, and it is the only abundant alkaline natural polysaccharide found in nature. With its excellent biocompatibility, biodegradability, antibacterial activity, and non-toxicity, chitosan shows broad application prospects in various fields such as biomedicine, cosmetics, food preservation, and environmental protection. It can be used as a key material for drug carriers and wound dressings, occupying an important position in the field of green polymer materials.

[0003] However, the inherent physicochemical defects of chitosan severely limit its industrial application and practical effectiveness. Its most critical limitation lies in its extremely poor solubility; it is insoluble in water, common organic solvents, and alkaline solutions, and can only dissolve in dilute acidic solutions. Furthermore, during the dissolution process, it easily forms aggregates due to hydrogen bonding between molecular chains, affecting the homogeneity of the solution.

[0004] To overcome the aforementioned shortcomings, existing technologies mostly employ chemical modification methods to structurally modify chitosan. Functional groups are introduced through reactions such as esterification, etherification, amidation, and graft copolymerization to prepare chitosan derivatives and improve its properties. Common modified products include quaternized chitosan, carboxymethyl chitosan, and acylated chitosan, which exhibit improvements in water solubility and antibacterial properties. However, chemical modification methods have inherent drawbacks: the reaction steps are complex, the preparation conditions are demanding, often requiring catalysts, high temperatures, or specific solvents, and byproducts can easily be generated, leading to a decrease in product purity; the natural biological activity of chitosan may be impaired during modification; and single modification strategies often only optimize one property, making it difficult to achieve synergistic improvements in multiple indicators such as solubility and stability.

[0005] In recent years, the rapid development of supramolecular chemistry has provided a new approach to optimizing the performance of natural polymer materials. Based on non-covalent intermolecular interactions (such as hydrogen bonds, electrostatic attraction, and van der Waals forces), supramolecular chemistry enables different components to self-assemble at the molecular scale into supramolecular systems with specific structures and functions without the need for complex covalent bond modifications. This allows for synergistic performance enhancement while retaining the inherent properties of the raw materials.

[0006] Organic acids are a class of widely available and biocompatible compounds, and some organic acids themselves possess antibacterial, antioxidant, and moisturizing biological activities; they are common raw materials in the hair care industry. However, there are currently no reports on chitosan-organic acid ionic salts.

[0007] Therefore, developing a chitosan-organic acid supramolecular ionic salt to improve the water solubility of chitosan, and using supramolecular ionic salt to improve severely damaged hair and achieve multiple functions such as repair and smoothing, are urgent problems to be solved. Summary of the Invention

[0008] [Technical Issues] Existing methods for improving the properties of chitosan have problems such as complex reaction steps and harsh preparation conditions, and they are prone to damaging the properties of chitosan itself. Chitosan has extremely poor solubility; There are currently no chitosan-organic acid ionic salts.

[0009] [Technical Solution] To address the aforementioned problems, this invention provides a chitosan-organic acid supramolecular ionic salt and its preparation method. Specifically, this invention involves mixing chitosan with one or more organic acids (maleic acid, sorbic acid, ferulic acid, caffeic acid, cinnamic acid, and fumaric acid) and a solvent, followed by drying to obtain the chitosan-organic acid supramolecular ionic salt. The chitosan-organic acid supramolecular ionic salt prepared by this invention can improve the water solubility of chitosan and improve severely damaged hair, offering multiple functions such as repair and smoothing, making it suitable for hair care products. Furthermore, the preparation method is simple, requiring no catalyst or high temperature and pressure, making it suitable for industrial use.

[0010] The first objective of this invention is to provide a method for preparing chitosan-organic acid supramolecular ionic salts, comprising the following steps: Chitosan, organic acid and solvent are mixed and dried to obtain chitosan-organic acid supramolecular ionic salt; The organic acid is any one or two of maleic acid, sorbic acid, ferulic acid, caffeic acid, cinnamic acid, and fumaric acid.

[0011] Furthermore, the method for preparing chitosan-organic acid supramolecular ionic salts includes the following steps: Chitosan, organic acid, and solvent are first dispersed at 25-50℃ for 1-3 hours, then heated to 50-80℃ and stirred at 300-600 rpm for 6-12 hours to obtain a clear liquid; then the clear liquid is dried to obtain chitosan-organic acid supramolecular ionic salt.

[0012] Furthermore, the mass ratio of chitosan, organic acid, and solvent is 3-35:65-97:350.

[0013] Furthermore, when there are two organic acids, their mass ratio is 1:1.

[0014] Furthermore, the solvent is water or an aqueous solution of ethanol with a mass fraction of 40-60%.

[0015] Furthermore, the dispersion is ultrasonic dispersion, with an ultrasonic power of 100-500W.

[0016] Furthermore, the drying process is spray drying.

[0017] Furthermore, spray drying is carried out at a temperature of 180-200℃ and a pressure of 0.2-0.5MPa for 4-8 hours.

[0018] The second objective of this invention is to prepare chitosan-organic acid supramolecular ionic salts using the method described herein.

[0019] Furthermore, the structural formula of chitosan-organic acid supramolecular ionic salt is as follows:

[0020] R1 is any one of maleic acid, sorbic acid, ferulic acid, caffeic acid, cinnamic acid, and fumaric acid; R2 is any one of maleic acid, sorbic acid, ferulic acid, caffeic acid, cinnamic acid, or fumaric acid; x is any integer from 1 to 100; y is any integer from 1 to 100.

[0021] Furthermore, the structural formulas of R1 and R2 can be any of the following, and R1 and R2 can be the same or different.

[0022] Furthermore, the structural formulas for R1 and R2 can be as follows:

[0023] or

[0024] or

[0025] or

[0026] or

[0027] or .

[0028] The third objective of this invention is the application of the chitosan-organic acid supramolecular ionic salt described herein in the preparation of hair care products or pharmaceuticals.

[0029] Furthermore, hair care products include: conditioner, hair oil, hair cream, hair wax, shampoo, after-wash sunscreen lotion, no-steam hair cream, sunscreen shampoo, medicated hair cream, conditioning shampoo, hair lotion, aftershave, etc.

[0030] A fourth object of the present invention is to provide a shampoo containing the chitosan-organic acid supramolecular ionic salt described in the present invention.

[0031] In one embodiment of the present invention, the mass concentration of chitosan-organic acid supramolecular ionic salt in the shampoo is 0.01-20%.

[0032] In one embodiment of the present invention, the shampoo comprises, by mass percentage: sodium dodecyl sulfate (SDS) 0.05-1%, cocamidopropyl betaine 0.01-1%, chitosan-organic acid supramolecular ion salt 0.01-1%, citric acid 0.1-0.5%, and water to 100%; The specific preparation method of shampoo includes the following steps: Mix SDS and water, then add cocamidopropyl betaine and chitosan-organic acid supramolecular ion salt, mix well, and adjust the pH to be close to the natural pH of the scalp using citric acid to obtain the shampoo.

[0033] The fifth objective of this invention is to provide a method for improving the water solubility of chitosan, which employs the chitosan-organic acid supramolecular ionic salt described in this invention.

[0034] The sixth objective of this invention is to provide a method for enhancing the repair and smoothing functions of hair care products, which utilizes the chitosan-organic acid supramolecular ionic salt described in this invention.

[0035] [Beneficial Effects] (1) The chitosan-organic acid supramolecular ionic salt prepared by the present invention can improve the water solubility of chitosan and improve severely damaged hair quality, taking into account multiple functions such as repair and smoothing, and is suitable for hair care products. (2) The preparation method of the present invention is simple, does not require catalysts, high temperature and high pressure, etc., and is suitable for industrial use. Attached Figure Description

[0036] Figure 1 The image shows the infrared spectrum of the chitosan-cinnamic acid supramolecular ionic salt in Example 1.

[0037] Figure 2 The image shows the infrared spectrum of the chitosan-cinnamic acid-caffeic acid supramolecular ion salt in Example 2.

[0038] Figure 3The images show fluorescence detection of hair strands; (a) untreated damaged hair; (b) reduced hair treated with thioglycolic acid; and (c) hair treated with the ionic salt of Example 1.

[0039] Figure 4 The images are scanning electron micrographs of hair strands; (a) untreated damaged hair; (b) reduced hair treated with thioglycolic acid; and (c) hair treated with the ionic salt of Example 1.

[0040] Figure 5 The water solubility stability of the ionic salts obtained in the examples and comparative examples was determined by diluting them 50 times with water and storing them at 45°C (oven) for 3 months. Detailed Implementation

[0041] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explanation of the present invention and are not intended to limit the present invention.

[0042] Test method: 1. Repair effect test: When hair is damaged, the disulfide bonds in the hair keratin are broken, resulting in loss of elasticity and shine, and making the hair dry and brittle. The breaking of disulfide bonds yields two free sulfhydryl groups, so measuring the sulfhydryl content in damaged hair can provide a relatively direct assessment of the degree of hair damage.

[0043] Rhodamine R2 (RB) is one of the most commonly used fluorescent dyes, and iodine solution (I 3- The reaction of I with RB can quench its fluorescence and reduce its fluorescence intensity, while the thiol group can reduce I. 3- Restore to I - This enhances fluorescence intensity. Through the fluorescent interaction between iodine solution and rhodamine R2, residual thiol groups in the hair can be reduced to I... 3- Then, the fluorescence intensity of the hair strands is observed under a fluorescence microscope. If the repair process is successful, the fluorescence intensity on the repaired hair strands should be much lower than that on the damaged hair strands, thus visualizing the repair effect of thiol groups. The concentration is 10. -3 10 mol / L iodine standard solution (solvent is water) -4 Prepare mol / L Rhodamine B solution (water as solvent) and acetate-sodium acetate buffer (pH 7).

[0044] The hair was placed in a reducing agent, mercaptoacetic acid aqueous solution (8% by mass, pH 8.5), and shaken at 50°C for 30 min in a constant temperature shaking incubator. After being removed, dried, and stored in nitrogen, the hair was reduced.

[0045] A suitable amount of hair was cut and soaked in different repair solutions (different ionic salt aqueous solutions with a mass fraction of 1%) at 50°C with shaking for 30 minutes. After removal, the hair was dried in a nitrogen atmosphere to obtain the repaired hair.

[0046] Several strands of repaired hair from each group were placed in 2 mL of iodine standard solution and vortexed at 25°C for 5 min. Then, 3 mL of rhodamine B solution and 5 mL of acetate-sodium acetate buffer were added. After standing for 10 min, the hair was removed and soaked in deionized water. After vortexing at 25°C for 5 min, the hair was removed and rinsed several times with deionized water to remove residual rhodamine B. The hair was then dried and observed under a 360 nm fluorescence microscope.

[0047] After processing and drying, the hair was cut into small segments of about 0.3 cm, fixed on the electron microscope stage with conductive adhesive, and the hair morphology was observed using a Hitachi S-4800 field emission scanning electron microscope.

[0048] 2. Friction coefficient test The experiment was conducted at a temperature of (25±2)℃ and a humidity of (50±5)% RH.

[0049] The ionic salt and water were mixed at a mass ratio of 1:99 and stirred at 20°C and 500 rpm for 3 minutes until fully dissolved. The pH was then adjusted to 8 with 1M NaOH solution to obtain the repair solution.

[0050] Each group of hair strands was immersed in a different repair solution for 30 seconds, and then air-dried in a constant temperature and humidity environment for 4 hours. The coefficient of friction of each group of hair strands was tested using a fiber friction coefficient tester, and the dynamic and static coefficients of friction of each group of hair strands before and after using the repair solution were compared. The average value was taken after measuring 15 relatively concentrated data sets for each group.

[0051] 3. Dry combing performance test The experiment was conducted at a temperature of (25±2)℃ and a RH of (50±5)%. A 40 cm long and 25 g human hair piece was selected and thoroughly moistened with 40℃ warm water. Using a dropper, 5 mL of a 10% SDS aqueous solution was evenly applied to both sides of the hair piece and rubbed to create foam. During rubbing, care should be taken to avoid folding or twisting the hair strands to prevent tangling. The foam was then rinsed off with warm water. The above operation was repeated twice and then the hair was placed in a constant temperature and humidity environment to air dry naturally.

[0052] Prepare 10 g of different ionic salts (prepared in the examples or comparative examples) with a mass fraction of 1%, and spray them evenly onto each hair strand. Perform simple combing using a comb. After the hair strands have air-dried at a constant temperature, test the dry combing performance of each strand using a combing instrument. Each group uses two hair sections of the same size for testing, and the test is repeated seven times. The combing performance curve is obtained by processing the data; the dry combing performance can be obtained by integrating the combing curve.

[0053] 4. Yield calculation: The formula for calculating yield is:

[0054] Among them, M X —Actual output; M t —Theoretical output.

[0055] 5. High and low temperature cycling: Freeze at -5℃, remove and thaw at 40℃. This constitutes one cycle. Repeat the cycle multiple times to observe whether a homogeneous, transparent and stable solution can still be formed.

[0056] Raw materials used in the examples: Chitosan: purity 99%, degree of deacetylation 90%, viscosity ≤500cps; Maleic acid: CAS (110-16-7). Sorbic acid: CAS (110-44-1); Ferulic acid: CAS (537-98-4); Caffeic acid: CAS (331-39-5); Cinnamic acid: CAS (140-10-3); Fumaric acid: CAS (110-17-8); All of the above-mentioned raw materials can be purchased commercially.

[0057] Example 1 Chitosan-Cinnamic Acid A method for preparing chitosan-cinnamic acid supramolecular ionic salt includes the following steps: Chitosan, cinnamic acid, and water were mixed in a mass ratio of 20:80:350 and first ultrasonically dispersed at 40℃ and 200W for 2 hours. Then, the mixture was heated to 70℃ and stirred at 600rpm for 8 hours to obtain a clear liquid. The clear liquid was then spray-dried at 200℃ and 0.3MPa for 6 hours to obtain chitosan-cinnamic acid supramolecular ionic salt.

[0058] Infrared spectrum of chitosan-cinnamic acid supramolecular ionic salt as shown in Figure Figure 1 As shown; from Figure 1It can be seen that, compared with the raw materials cinnamic acid and chitosan, the supramolecular ionic salt has a thickness of 3461-2500 cm⁻¹. -1 The presence of a distinct and broad absorption peak is a hallmark of the protonation of the amino group (-NH2) in chitosan to form a salt (+NH3), indicating that the carboxyl hydroxyl group in cinnamic acid has successfully transferred to the amino group in chitosan. Furthermore, the carbonyl group in cinnamic acid (1627 cm⁻¹) shows a strong absorption peak. -1 After forming an ionic salt, it shifts to 1637 cm. -1 This also indicates that the carbonyl electron cloud density changes after salt formation, thereby altering infrared absorption; the above results confirm that Example 1 successfully synthesized supramolecular chitosan-cinnamic acid ion salt.

[0059] The obtained ionic salts were subjected to performance tests, and the results are as follows: The chitosan-cinnamic acid supramolecular ionic salt obtained contained 20 wt% chitosan. It was diluted with water by 1, 5, 10, 20 and 50 times. The supramolecular ionic salt and each diluted system were placed at room temperature under natural light for 3 months, in an oven at 45℃ for 3 months, and subjected to high and low temperature (-5~40℃) cycles for 15 times. No insoluble matter was precipitated and no color change was observed.

[0060] Figure 3 The images show fluorescence detection of hair strands; (a) untreated damaged hair; (b) reduced hair treated with thioglycolic acid; and (c) hair treated with the ionic salt of Example 1. Figure 3 It can be seen that untreated damaged hair emits strong fluorescence under a fluorescence microscope, and the gaps in the hair cuticle are clearly visible. This phenomenon indicates that the hair cuticle of damaged hair is in an open state, exposing the thiol-containing keratin structure inside the hair. Reduced hair treated with thioglycolic acid also exhibits strong fluorescence properties; not only are the gaps in the hair cuticle further enlarged, but large fluorescent spots also appear on the hair surface due to cuticle peeling. This indicates that thioglycolic acid breaks the disulfide bonds in the hair, leading to open and damaged cuticles, while also increasing the content of free thiol groups in the hair. Conversely, reduced hair treated with supramolecular ionic salts shows a significant decrease in fluorescence intensity, and the gaps in the hair cuticle are almost invisible on the hair surface. This indicates that the product can effectively reduce the free thiol groups on the hair surface, while filling and repairing damaged and open cuticles, thus making the hair surface smoother and more even.

[0061] Figure 4 Scanning electron micrographs of hair strands; processing states of the three samples and... Figure 3 Consistent. By Figure 4It is evident that untreated damaged hair has a rough surface with numerous damage sites, and the hair cuticles show obvious signs of lifting and peeling. Hair treated with thioglycolic acid exhibits even greater surface roughness, an increased number of damage sites, and more pronounced cuticle lifting and peeling, with some areas showing complete cuticle damage and peeling. In contrast, hair treated with this product shows significantly reduced surface damage, fewer damage sites, smoother cuticles, and a significantly reduced tendency to lift. In conclusion, from a macroscopic perspective, this product can effectively reduce the degree of hair damage.

[0062] Example 2 Chitosan-cinnamic acid-caffeic acid A method for preparing chitosan-cinnamic acid-caffeic acid supramolecular ionic salt includes the following steps: Chitosan, cinnamic acid, caffeic acid, and water were mixed in a mass ratio of 20:45:45:350 and ultrasonically dispersed at 30℃ and 300W for 2 hours. Then, the mixture was heated to 65℃ and stirred at 600rpm for 12 hours to obtain a clear liquid. The clear liquid was then spray-dried at 200℃ and 0.3MPa for 6 hours to obtain a chitosan-cinnamic acid-caffeic acid supramolecular ionic salt.

[0063] Infrared spectrum of chitosan-cinnamic acid-caffeic acid supramolecular ion salt as shown in Figure Figure 2 As shown; from Figure 2 It can be seen that, compared with the raw materials cinnamic acid, caffeic acid, and chitosan, the supramolecular ionic salt has a thickness of 3298-2500 cm⁻¹. -1 The presence of a distinct and broad absorption peak is a hallmark of the protonation of the amino groups (-NH2) in chitosan to form salts (+NH3), indicating that the carboxyl hydroxyl groups in cinnamic acid and caffeic acid have successfully transferred to the amino groups in chitosan. Furthermore, the carbonyl groups in cinnamic acid and caffeic acid (1627 cm⁻¹) show a strong absorption peak. -1 1645 cm -1 After forming an ionic salt, it shifts to 1638 cm⁻¹. -1 This also indicates that the carbonyl electron cloud density changes after salt formation, thereby altering infrared absorption; the above results confirm that Example 2 successfully synthesized supramolecular chitosan-cinnamic acid-caffeic acid ion salt.

[0064] The obtained ionic salts were subjected to performance tests, and the results are as follows: The chitosan-cinnamic acid-caffeic acid supramolecular ionic salt obtained contained 18.18 wt% chitosan. After dilution with water by 1, 5, 10, 20 and 50 times, the supramolecular ionic salt and each diluted system were placed at room temperature under natural light for 3 months, in an oven at 45℃ for 3 months, and subjected to high and low temperature (-5~40℃) cycles for 15 times. No insoluble matter was precipitated and no color change was observed.

[0065] Example 3 Chitosan-Caffeic Acid A method for preparing chitosan-caffeic acid supramolecular ionic salt includes the following steps: Chitosan, caffeic acid, and water were dispersed by ultrasonication at 25°C and 500W for 2 hours in a mass ratio of 30:65:350. Then, the mixture was heated to 65°C and stirred at 600 rpm for 12 hours to obtain a clear liquid. The clear liquid was then spray-dried at 200°C and 0.3 MPa for 6 hours to obtain chitosan-caffeic acid supramolecular ionic salt.

[0066] The obtained ionic salts were subjected to performance tests, and the results are as follows: The chitosan-caffeic acid supramolecular ionic salt obtained contained 31.58 wt% chitosan. After dilution with water by 1, 5, 10, 20 and 50 times, the supramolecular ionic salt and each diluted system were placed at room temperature under natural light for 3 months, in an oven at 45℃ for 3 months, and subjected to high and low temperature (-5~40℃) cycles for 15 times. No insoluble matter was precipitated and no color change was observed.

[0067] Example 4 Chitosan-Cinnamic Acid A method for preparing chitosan-cinnamic acid supramolecular ionic salt includes the following steps: Chitosan, cinnamic acid, and water were mixed in a mass ratio of 30:80:350 and first ultrasonically dispersed at 35℃ and 300W for 3 hours. Then, the mixture was heated to 75℃ and stirred at 600rpm for 10 hours to obtain a clear liquid. The clear liquid was then spray-dried at 200℃ and 0.3MPa for 6 hours to obtain chitosan-cinnamic acid supramolecular ionic salt.

[0068] The obtained ionic salts were subjected to performance tests, and the results are as follows: The chitosan-cinnamic acid supramolecular ionic salt obtained contained 27.27 wt% chitosan. After dilution with water by 1, 5, 10, 20 and 50 times, the supramolecular ionic salt and each diluted system were placed at room temperature under natural light for 3 months, in an oven at 45℃ for 3 months, and subjected to high and low temperature (-5~40℃) cycles for 15 times. No insoluble matter was precipitated and no color change was observed.

[0069] Example 5 Chitosan-maleic acid The cinnamic acid in Example 1 was replaced with maleic acid, while other aspects remained the same as in Example 1, to obtain chitosan-maleic acid supramolecular ionic salt.

[0070] The obtained ionic salts were subjected to performance tests, and the results are as follows: The chitosan-maleic acid supramolecular ionic salt obtained contained 20 wt% chitosan. After dilution with water by 1, 5, 10, 20 and 50 times, the supramolecular ionic salt and each diluted system were placed at room temperature under natural light for 3 months, in an oven at 45℃ for 3 months, and subjected to high and low temperature (-5~40℃) cycles for 15 times. No insoluble matter was precipitated and no color change was observed.

[0071] Example 6 Chitosan-sorbic acid-fumaric acid A method for preparing chitosan-sorbic acid-fumaric acid supramolecular ionic salt includes the following steps: Chitosan, sorbic acid, fumaric acid, and water were mixed in a mass ratio of 20:35:35:350 and first ultrasonically dispersed at 50℃ and 200W for 3 hours. Then, the mixture was heated to 80℃ and stirred at 600rpm for 6 hours to obtain a clear liquid. The clear liquid was then spray-dried at 200℃ and 0.3MPa for 6 hours to obtain the chitosan-sorbic acid-fumaric acid supramolecular ionic salt.

[0072] The obtained ionic salts were subjected to performance tests, and the results are as follows: The chitosan-sorbic acid-fumaric acid supramolecular ionic salt obtained contained 22.22 wt% chitosan. After dilution with water by 1, 5, 10, 20 and 50 times, the supramolecular ionic salt and each diluted system were placed at room temperature under natural light for 3 months, in an oven at 45℃ for 3 months, and subjected to high and low temperature (-5~40℃) cycles for 15 times. No insoluble matter was precipitated and no color change was observed.

[0073] Example 7 Chitosan-Cinnamic Acid-Fumaric Acid A method for preparing chitosan-cinnamic acid-fumaric acid supramolecular ionic salt, comprising the following steps: Chitosan, cinnamic acid, fumaric acid, and water were mixed in a mass ratio of 20:40:40:350 and first ultrasonically dispersed at 30℃ and 300W for 3 hours. Then, the mixture was heated to 55℃ and stirred at 600rpm for 12 hours to obtain a clear liquid. The clear liquid was then spray-dried at 200℃ and 0.3MPa for 6 hours to obtain a chitosan-cinnamic acid-fumaric acid supramolecular ionic salt.

[0074] The obtained ionic salts were subjected to performance tests, and the results are as follows: The chitosan-cinnamic acid-fumaric acid supramolecular ionic salt obtained contained 20wt% chitosan. After dilution with water by 1, 5, 10, 20 and 50 times, the supramolecular ionic salt and each diluted system were placed at room temperature under natural light for 3 months, in an oven at 45℃ for 3 months, and subjected to high and low temperature (-5~40℃) cycles for 15 times. No insoluble matter was precipitated and no color change was observed.

[0075] Example 8 Chitosan-Caffeic Acid-Maleic Acid In Example 2, cinnamic acid was replaced with maleic acid, while other aspects remained the same as in Example 2, resulting in chitosan-caffeic acid-maleic acid supramolecular ionic salt.

[0076] The obtained ionic salts were subjected to performance tests, and the results are as follows: The chitosan-caffeic acid-maleic acid supramolecular ionic salt obtained contained 18.18 wt% chitosan. After dilution with water by 1, 5, 10, 20 and 50 times, the supramolecular ionic salt and each diluted system were placed at room temperature under natural light for 3 months, in an oven at 45℃ for 3 months, and subjected to high and low temperature (-5~40℃) cycles for 15 times. No insoluble matter was precipitated and no color change was observed.

[0077] Example 9 In Example 2, the water was adjusted to be an aqueous solution of ethanol with a mass fraction of 60%, while other aspects remained the same as in Example 2, to obtain chitosan-caffeic acid-maleic acid supramolecular ionic salt.

[0078] The obtained ionic salts were subjected to performance tests, and the results are as follows: The combing performance test results of Examples 1-9 are as follows: Table 1

[0079] Comparative Example 1 The cinnamic acid in Example 1 was replaced with oleic acid, while other aspects remained the same as in Example 1, resulting in an ionic salt.

[0080] Comparative Example 2 The cinnamic acid in Example 1 was replaced with chlorogenic acid, while all other aspects remained the same as in Example 1, to obtain an ionic salt.

[0081] Comparative Example 3 The mass ratio of chitosan, cinnamic acid, and water in Example 1 was adjusted to 40:80:350, while other aspects remained the same as in Example 1, to obtain an ionic salt.

[0082] Comparative Example 4 The mass ratio of chitosan, cinnamic acid, and water in Example 1 was adjusted to 20:50:350, while other aspects remained the same as in Example 1, to obtain an ionic salt.

[0083] Comparative Example 5 Commercially available silk protein peptides (99%).

[0084] Comparative Example 6 A method for preparing chitosan-cinnamic acid supramolecular ionic salt includes the following steps: Chitosan, cinnamic acid, and water were reacted at a mass ratio of 20:80:350 at 70°C and 600 rpm for 12 hours to obtain a clear liquid. The clear liquid was then spray-dried at 200°C and 0.3 MPa for 6 hours to obtain chitosan-cinnamic acid supramolecular ionic salt.

[0085] Comparative Example 7 A method for preparing chitosan-cinnamic acid supramolecular ionic salt includes the following steps: Chitosan, cinnamic acid, and water were reacted at a mass ratio of 20:80:350, stirred at 70℃ and 600rpm for 8 hours, and then ultrasonically dispersed at 40℃ and 200W for 2 hours to obtain a clear liquid. The clear liquid was then spray-dried at 200℃ and 0.3MPa for 6 hours to obtain chitosan-cinnamic acid supramolecular ionic salt.

[0086] Comparative Example 8 The stirring temperature in Example 1 was adjusted to 40°C, while other aspects remained the same as in Example 1, to obtain an ionic salt.

[0087] Comparative Example 9 The ultrasonic dispersion temperature in Example 1 was adjusted to 60°C, while other parameters remained the same as in Example 1, to obtain an ionic salt.

[0088] The obtained ionic salts were subjected to performance tests, and the results are as follows: Table 3

[0089] Example 10 Shampoo was prepared using the ionic salts obtained in Examples 1 and 2, and the formulation is shown in Table 4. Table 4

[0090] The preparation method is as follows: In a beaker, the main surfactant sodium dodecyl sulfonate (SDS) is mixed with an appropriate amount of water. Cocamidopropyl betaine and ionic salt are added to the mixture and stirred until homogeneous. The pH of the mixture is adjusted to be close to the natural pH of the scalp (5.5) using citric acid. Water is then added to the designed system mass to prepare the shampoo.

[0091] The ionic salts prepared in Examples 1 and 2 were added to the shampoo prepared above as functional ingredients as a control sample, and no functional ingredients were added as a blank sample. The dry combing performance of the control sample and the blank sample after treating real human hair sections was tested, and the results are shown in Table 5.

[0092] Table 5 Dry combing work

[0093] The results showed that the shampoos prepared using the ionic salts of Examples 1 and 2 had a smoothing effect on the hair.

[0094] Comparative Example 10 In Example 10, the ionic salt in Example 1 was replaced with the same mass of chitosan and cinnamic acid, and no ionic salt was formed; otherwise, it remained the same as in Example 10.

[0095] The results showed that after the prepared shampoo was used to treat real hair samples, the dry combing performance was tested and the result was 10.66211. This result was not significantly different from the dry combing performance of the shampoo without added active ingredients, proving that the shampoo prepared in Comparative Example 10 did not have the effect of smoothing hair.

[0096] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A method for preparing chitosan-organic acid supramolecular ionic salts, characterized in that, Includes the following steps: Chitosan, organic acid and solvent are mixed and dried to obtain chitosan-organic acid supramolecular ionic salt; The organic acid is any one or two of maleic acid, sorbic acid, ferulic acid, caffeic acid, cinnamic acid, and fumaric acid.

2. The method according to claim 1, characterized in that, A method for preparing chitosan-organic acid supramolecular ionic salts includes the following steps: Chitosan, organic acid, and solvent are first dispersed at 25-50℃ for 1-3 hours, then heated to 50-80℃ and stirred at 300-600 rpm for 6-12 hours to obtain a clear liquid; then the clear liquid is dried to obtain chitosan-organic acid supramolecular ionic salt. Preferably, the mass ratio of chitosan, organic acid, and solvent is 3-35:65-97:

350.

3. The method according to claim 1, characterized in that, When there are two organic acids, their mass ratio is 1:1; Preferably, the solvent is water or an aqueous solution of ethanol with a mass fraction of 40-60%; Preferably, the dispersion is ultrasonic dispersion, with an ultrasonic power of 100-500W; Preferably, the drying method is spray drying, specifically spray drying at a temperature of 180-200℃ and a pressure of 0.2-0.5MPa for 4-8 hours.

4. The chitosan-organic acid supramolecular ionic salt prepared by the method according to any one of claims 1-3.

5. The chitosan-organic acid supramolecular ionic salt according to claim 4, characterized in that, The structural formula of chitosan-organic acid supramolecular ionic salt is as follows: Formula I R1 is any one of maleic acid, sorbic acid, ferulic acid, caffeic acid, cinnamic acid, and fumaric acid; R2 is any one of maleic acid, sorbic acid, ferulic acid, caffeic acid, cinnamic acid, or fumaric acid; x is any integer from 1 to 100; y is any integer from 1 to 100.

6. The use of the chitosan-organic acid supramolecular ionic salt according to claim 4 in the preparation of hair care products or pharmaceuticals.

7. A shampoo, characterized in that, It contains the chitosan-organic acid supramolecular ionic salt as described in claim 4.

8. The shampoo according to claim 7, characterized in that, The mass concentration of chitosan-organic acid supramolecular ionic salt in shampoo is 0.01-20%.

9. A method for improving the water solubility of chitosan, characterized in that, It contains the chitosan-organic acid supramolecular ionic salt as described in claim 4.

10. A method for enhancing the repairing and smoothing functions of hair care products, characterized in that, It contains the chitosan-organic acid supramolecular ionic salt as described in claim 4.

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