A long-lasting sodium hyaluronate derivative for hair repair and its preparation method

Abstract

The present invention discloses a long-retention sodium hyaluronate derivative for hair repair and its preparation method. This invention utilizes click chemistry to synthesize a long-retention sodium hyaluronate derivative that exhibits excellent hair repair efficacy. The synthesized sodium hyaluronate derivative is chemically bonded to increase the residence time of the sodium hyaluronate's active molecules, thereby enhancing the hair care benefits of sodium hyaluronate.

Description

Technical Field

[0001] The invention belongs to the technical field of hair products, and in particular relates to a long-stay sodium hyaluronate derivative for hair repair and a preparation method thereof. Background Art

[0002] Sodium hyaluronate is a macromolecular bioactive compound that binds water molecules primarily through hydrogen bonding, resulting in its moisturizing properties. It has been widely used in cosmetics for several years. In recent years, local companies have also utilized enzymatic oligomerization technology to produce sodium hyaluronate in various structures, expanding the deep moisturizing and repairing properties of sodium hyaluronate with varying molecular weights. The hair care benefits of sodium hyaluronate have been increasingly recognized in recent years. It can affect the mechanical properties of hair by regulating the water content in the hair, providing moisturizing effects and enhancing combability and gloss.

[0003] As a water-soluble polymer, sodium hyaluronate has difficulty depositing and penetrating hair, a problem exacerbated by high molecular weight hyaluronate. Low affinity for hair and a short residence time are the primary factors limiting the effectiveness of sodium hyaluronate in hair care. Furthermore, once sodium hyaluronate penetrates the hair, it primarily relies on weak hydrogen bonds, making it susceptible to environmental influences and causing significant loss during daily washing. Therefore, developing functional molecules that achieve enhanced residence time through strong bonds has become a research hotspot.

[0004] At the same time, with changing consumer attitudes, modern consumers are getting their hair permed more and more frequently. The perming process reduces the existing disulfide bonds in the hair, generating free thiols. These free thiols provide an opportunity to develop long-retention sodium hyaluronate molecules. Summary of the Invention

[0005] To address the shortcomings of the existing technology, the present invention provides a long-retention sodium hyaluronate derivative for hair repair and its preparation method. The present invention utilizes click chemistry to synthesize a long-retention sodium hyaluronate derivative that exhibits excellent hair repair effects. The synthesized sodium hyaluronate derivative is chemically bonded to increase the retention time of the sodium hyaluronate's active molecules, thereby enhancing the hair care effects of sodium hyaluronate.

[0006] The technical solutions of the present invention are as follows:

[0007] The present invention first protects a sodium hyaluronate derivative for hair repair, and the structural formula of the sodium hyaluronate derivative is as follows:

[0008]

[0009] R1 includes -CH=CH2, -C(CH3)=CH2, -CH=CH-COOH, -CH=CH-CH3, -CH=CH-CH2CH3 or One of them.

[0010] Furthermore, the specific structural formula of the sodium hyaluronate derivative is:

[0011]

[0012] Any one of .

[0013] The present invention also protects a method for preparing the sodium hyaluronate derivative, which comprises the following steps:

[0014] (1) Sodium hyaluronate was dissolved in distilled water overnight to obtain a sodium hyaluronate solution; tetrahydrofuran (THF) was added and stirred evenly, and triethanolamine (TEA) and 4-dimethylaminopyridine (DMPA) were added and stirred to obtain a reaction solution I;

[0015] (2) In a second reaction flask, after mixing the organic acid and tetrahydrofuran, triethanolamine and 2,4,6-trichlorobenzoyl chloride (TCBC) were added in sequence, and stirred to react to obtain reaction solution II;

[0016] (3) Add reaction solution II to reaction solution I of step (1), stir and react at room temperature, add saturated sodium chloride aqueous solution to precipitate and separate the crude product, and then wash; after standing and settling, pour out the clear liquid, and dry the precipitate for 24 hours or more to obtain a sodium hyaluronate derivative.

[0017] Furthermore, in step (1), the molecular weight of the sodium hyaluronate is 42 kDa-1460 kDa.

[0018] Furthermore, in step (1), the mass fraction of the sodium hyaluronate solution is 1-10%.

[0019] Furthermore, in step (1), the mass volume ratio of sodium hyaluronate to tetrahydrofuran (g / mL) is 2-5:50; the mass volume ratio of sodium hyaluronate to triethanolamine (g / mL) is 5:3.5-4; the mass ratio of sodium hyaluronate to 4-dimethylaminopyridine is 5:0.010-0.015; and the stirring temperature is 20-60°C.

[0020] Furthermore, in step (2), the organic acid is an organic acid containing an α-unsaturated bond.

[0021] Furthermore, the organic acid includes one or more of fumaric acid, maleic acid, acrylic acid, 2-butenoic acid, 2-pentenoic acid, and 2-hexenoic acid.

[0022] Furthermore, in step (2), the mass volume ratio of the organic acid to tetrahydrofuran is 1-5:50; the molar ratio of the organic acid to triethanolamine is 0.5-1:1; the molar ratio of the organic acid to 2,4,6-trichlorobenzoyl chloride is 0.5-1:1; the reaction temperature is room temperature, the time is 0.5h, and the room temperature is 20-30°C.

[0023] Furthermore, in step (3), the mass ratio of the organic acid in the reaction solution II to the sodium hyaluronate in the reaction solution I is 0.05-0.075:1; the reaction temperature is room temperature, and the reaction time is 2-3 hours; and the volume ratio of the saturated sodium chloride solution to the reaction mixture is 4-5:1.

[0024] The present invention also protects a sodium hyaluronate derivative prepared by the above method.

[0025] The present invention also protects a use of the sodium hyaluronate derivative for hair repair, wherein the sodium hyaluronate derivative reacts with free thiol groups in the hair through a Michael addition reaction to achieve retention in the hair and improve the mechanical properties of the hair.

[0026] Another object of the present invention is to protect a method for achieving long-term retention and hair repair through a click reaction of the sodium hyaluronate derivative obtained by the above reaction.

[0027] Furthermore, the method comprises the following steps:

[0028] (1) Preparing a sodium hyaluronate derivative repair agent solution: dissolving a sodium hyaluronate derivative in deionized water and stirring evenly, adding triethanolamine to adjust the pH to 5-7 to obtain a sodium hyaluronate derivative repair agent solution;

[0029] (2) Soak the damaged hair bundle in the sodium hyaluronate derivative repair agent solution of step (1) and react at 20°C-50°C for 5 minutes-30 minutes.

[0030] Furthermore, in step (1), the content of sodium hyaluronate derivative in the sodium hyaluronate derivative repair agent solution is 0.1%-1%, preferably 0.5%; and the pH is preferably 6.

[0031] Furthermore, in step (2), the reaction temperature is preferably 40° C., and the reaction time is preferably 10 min-20 min.

[0032] The beneficial technical effects of the present invention are:

[0033] The sodium hyaluronate derivative prepared by the esterification reaction of sodium hyaluronate with an organic acid containing an α-unsaturated bond can be used in the technical field of hair products.

[0034] Through a click reaction, the carbon-carbon double bond groups of the sodium hyaluronate derivative prepared by the present invention can form covalent bonds with free thiol groups in the hair, thereby firmly connecting the sodium hyaluronate derivative to the hair keratin, achieving long-term residence on the hair and reflecting a better repair effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is the retention effect of the product of Example 1 of the present invention on the hair surface.

[0036] Figure 2 The product of Example 1 of the present invention 1 H-NMR characterization results.

[0037] Figure 3 The product of Example 2 of the present invention 1 H-NMR characterization results.

[0038] Figure 4 For the product of Example 3 of the present invention 1 H-NMR characterization results. DETAILED DESCRIPTION

[0039] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0040] The preparation method of the sodium hyaluronate derivative of the present invention comprises the following steps:

[0041] (1) Sodium hyaluronate was dissolved in distilled water overnight to obtain a sodium hyaluronate solution; tetrahydrofuran (THF) was added and stirred evenly, and triethanolamine (TEA) and 4-dimethylaminopyridine (DMPA) were added and stirred to obtain a reaction solution I;

[0042] (2) In a second reaction flask, after mixing the organic acid and tetrahydrofuran, triethanolamine and 2,4,6-trichlorobenzoyl chloride (TCBC) were added in sequence, and stirred to react to obtain reaction solution II;

[0043] (3) Add reaction solution II to reaction solution I of step (1), stir and react at room temperature, add saturated sodium chloride aqueous solution to precipitate and separate the crude product, and then wash; after standing and settling, pour out the clear liquid, and dry the precipitate for 24 hours or more to obtain a sodium hyaluronate derivative.

[0044] It should be noted that healthy hair contains essentially no free sulfhydryl groups, so the present invention is not applicable to healthy hair. Hair that has been treated with perms or dyes contains a considerable amount of free sulfhydryl groups, so the molecules and methods of use proposed in the present invention can be directly applied to perms or dyes.

[0045] In one embodiment of the present invention, in step (1), the sodium hyaluronate is sodium hyaluronate.

[0046] In one embodiment of the present invention, in step (1), the mass fraction of the sodium hyaluronate solution is 1%, 5%, 8% or 10%.

[0047] In one embodiment of the present invention, in step (1), the mass volume ratio of sodium hyaluronate to tetrahydrofuran (g / mL) is 3:50, 4:50 or 5:50; the mass volume ratio of sodium hyaluronate to triethanolamine (g / mL) is 5:3.5, 5:3.8 or 5:4; the mass ratio of sodium hyaluronate to 4-dimethylaminopyridine is 5:0.010, 5:0.012 or 5:0.015; and the stirring temperature is 20°C, 40°C, 50°C or 60°C.

[0048] In step (2), the organic acid is an organic acid containing an α-unsaturated bond.

[0049] In one embodiment of the present invention, the organic acid is fumaric acid, maleic acid, acrylic acid, 2-butenoic acid, 2-pentenoic acid or 2-hexenoic acid.

[0050] In one embodiment of the present invention, in step (2), the mass volume ratio of the organic acid to tetrahydrofuran is 1:50, 1.5:50, 3:50, 4:50 or 5:50; the molar ratio of the organic acid to triethanolamine is 0.5:1, 0.8:1 or 1:1; the molar ratio of the organic acid to 2,4,6-trichlorobenzoyl chloride is 0.5:1, 0.8:1 or 1:1; the reaction temperature is room temperature, the time is 0.5h, and the room temperature is 20°C, 25°C or 30°C.

[0051] In one embodiment of the present invention, in step (3), the mass ratio of the organic acid in the reaction solution II to the sodium hyaluronate in the reaction solution I is 0.05:1, 0.06:1 or 0.075:1; the reaction temperature is room temperature and the reaction time is 3 hours; the volume ratio of the saturated sodium chloride solution to the reaction mixture is 4:1, 4.5:1 or 5:1.

[0052] The present invention will be further described below by way of examples and the like.

[0053] Example 1

[0054] Sodium hyaluronate fumarate, its synthesis route is as follows:

[0055]

[0056] The specific preparation method is:

[0057] (1) Sodium hyaluronate (370 kDa, 5 g) was dissolved in 100 ml of distilled water overnight. 50 ml of tetrahydrofuran (THF) was slowly added to the solution. After the solution became homogeneous, triethanolamine (3.5 ml, 25 mmol) and 4-dimethylaminopyridine (DMAP, 0.015 g, 0.125 mmol) were added and the mixture was stirred until a clear solution was obtained, i.e., reaction solution I.

[0058] (2) In a reaction flask, fumaric acid was dissolved in tetrahydrofuran (10 ml) at a mass ratio of fumaric acid to sodium hyaluronate = 0.05:1. Triethanolamine (TEA, 5 ml, 25 mmol) was then added, followed by an equimolar amount of 2,4,6-trichlorobenzoyl chloride (TCBC) to the fumaric acid. The mixture was stirred at room temperature (25°C) for 30 minutes to obtain reaction solution II.

[0059] (3) Add reaction solution II to reaction solution I. Allow the mixture to react at room temperature for 3 hours under vigorous stirring to ensure good homogenization of the components to obtain a reaction mixture; add 100 ml of saturated sodium chloride aqueous solution to the reaction mixture at a volume ratio of 5:1 to the reaction mixture to precipitate and separate the crude product. Thereafter, wash the product with an excess of anhydrous isopropanol (250 ml). Decant the white precipitate and dry it in an oven at 40°C for at least 24 hours to obtain sodium hyaluronate fumarate. 1 The H-NMR characterization results are as follows Figure 2 shown.

[0060] Example 2 (Molecular expansion, changing fumaric acid to 2-pentenoic acid, changing the molecular weight of sodium hyaluronate from 370 kDa to 1460 kDa, and changing the organic acid:HA molar ratio from 1.5:1 to 1.25:1)

[0061]

[0062] The specific preparation method is:

[0063] (1) Sodium hyaluronate (1460 kDa, 5 g, 12.5 mmol) was dissolved in 100 ml of distilled water overnight. 50 ml of tetrahydrofuran (THF) was slowly added to the solution. After the solution became homogeneous, triethanolamine (3.5 ml, 25 mmol) and 4-dimethylaminopyridine (DMPA, 0.015 g, 0.125 mmol) were added, and the mixture was stirred until a clear solution was obtained.

[0064] (2) In a reaction flask, 2-pentenoic acid was dissolved in tetrahydrofuran (10 ml) at a mass ratio of 2-pentenoic acid to sodium hyaluronate = 0.05:1. Triethanolamine (TEA, 5 ml, 25 mmol) was then added, followed by an equimolar amount of 2,4,6-trichlorobenzoyl chloride (TCBC) to the 2-pentenoic acid, and the mixture was stirred at room temperature (25°C) for 30 minutes.

[0065] (3) The reaction solution was added to the solution obtained in (1). The mixture was allowed to react at room temperature for 3 hours under vigorous stirring to ensure good homogenization of the components. 100 ml of supersaturated sodium chloride aqueous solution was added at a volume ratio of saturated sodium chloride aqueous solution to the reaction mixture of 5:1 to precipitate and separate the crude product. Thereafter, the product was washed with an excess of anhydrous isopropyl alcohol (250 ml). The white precipitate was decanted and dried in an oven at 40°C for at least 24 hours to obtain sodium hyaluronate 2-pentenoate.

[0066] Example 3 (Molecular expansion, fumaric acid was changed to acrylic acid, the molecular weight of sodium hyaluronate was changed from 370 kDa to 42 kDa, the mass ratio of organic acid:sodium hyaluronate was changed from 0.05:1 to 0.06:1, and the time of step (2) was changed from 30 min to 60 min)

[0067]

[0068] The specific preparation method is:

[0069] (1) Sodium hyaluronate (42 kDa, 5 g) was dissolved in 100 ml of distilled water overnight. 50 ml of tetrahydrofuran (THF) was slowly added to the solution. After the solution became homogeneous, triethanolamine (3.5 ml, 25 mmol) and 4-dimethylaminopyridine (DMPA, 0.015 g, 0.125 mmol) were added and the mixture was stirred until a clear solution was obtained.

[0070] (2) In a reaction flask, acrylic acid was dissolved in tetrahydrofuran (10 ml) at a mass ratio of acrylic acid to sodium hyaluronate = 0.06:1. Triethanolamine (TEA, 5 ml, 25 mmol) was then added, followed by an equimolar amount of 2,4,6-trichlorobenzoyl chloride (TCBC) to the acrylic acid, and the mixture was stirred at room temperature (25°C) for 60 minutes.

[0071] (3) The reaction solution was added to the solution obtained in (1). The mixture was allowed to react at room temperature for 3 hours under vigorous stirring to ensure good homogenization of the components. 100 ml of supersaturated sodium chloride aqueous solution was added at a volume ratio of saturated sodium chloride aqueous solution to the reaction mixture of 5:1 to precipitate and separate the crude product. Thereafter, the product was washed with an excess of anhydrous isopropyl alcohol (250 ml). The white precipitate was decanted and dried in an oven at 40°C for at least 24 hours to obtain sodium hyaluronate acrylate.

[0072] Application example: Repair of damaged hair

[0073] Daily perming and dyeing procedures can break disulfide bonds in hair, generating free sulfhydryl groups. This further damages the hair structure, leading to a decrease in mechanical properties and poor combing. The present invention designed various experiments to repair damaged hair strands, demonstrating that the proposed sodium hyaluronate derivative can restore both mechanical and combing properties.

[0074] The damaged hair tresses were prepared by simulating the perm process. The damaged hair tresses were obtained from healthy Asian black hair and incubated with 6% thioglycolic acid for 3 hours. The sodium hyaluronate derivative repair agent solution and repair method are as described in Application Examples 1-4.

[0075] Application Example 1:

[0076] The damaged hair repair method specifically comprises the following steps:

[0077] (1) Sodium hyaluronate fumarate was prepared according to the method of Example 1;

[0078] (2) 0.5 g of sodium hyaluronate fumarate and 99.5 g of deionized water were stirred and dissolved, and triethanolamine was added to adjust the pH to 7.0 to obtain a 0.5 wt% repair agent solution;

[0079] (3) Weigh 0.5 g of damaged hair (damaged hair is homemade to simulate the perm process) and soak it in the repair solution. Set the reaction temperature to 40°C and the reaction time to 15 min. Take it out and dry it to obtain the repaired hair.

[0080] Application Example 2:

[0081] The damaged hair repair method specifically comprises the following steps:

[0082] (1) Sodium hyaluronate fumarate was prepared according to the method of Example 1;

[0083] (2) 0.3 g of sodium hyaluronate fumarate and 99.7 g of deionized water were stirred and dissolved, and citric acid was added to adjust the pH to 5.0 to obtain a 0.3% wt repair agent solution;

[0084] (3) Weigh 0.5 g of damaged hair (damaged hair is homemade to simulate the perm process) and soak it in the repair solution. Set the reaction temperature to 40°C and the reaction time to 15 min. Take it out and dry it to obtain the repaired hair.

[0085] Application Example 3:

[0086] The damaged hair repair method specifically comprises the following steps:

[0087] (1) Sodium hyaluronate acrylate was prepared according to the method of Example 3;

[0088] (2) 2.0 g of sodium hyaluronate acrylate and 98.0 g of deionized water were stirred and dissolved, and triethanolamine was added to adjust the pH to 6.0 to obtain a 2% wt repair agent solution;

[0089] (3) Weigh 0.5 g of damaged hair (damaged hair is homemade to simulate the perm process) and soak it in the repair solution. Set the reaction temperature to 40°C and the reaction time to 5 min. Take it out and dry it to obtain the repaired hair.

[0090] Application Example 4:

[0091] The damaged hair repair method specifically comprises the following steps:

[0092] (1) Sodium hyaluronate fumarate was prepared according to the method of Example 1;

[0093] (2) 0.5 g of sodium hyaluronate fumarate and 99.5 g of deionized water were stirred and dissolved, and citric acid was added to adjust the pH to 5.0 to obtain a 0.5% wt repair agent solution;

[0094] (3) Weigh 0.5 g of damaged hair (damaged hair is homemade to simulate the perm process) and soak it in the repair solution. Set the reaction temperature to 25°C and the reaction time to 15 min. Take it out and dry it to obtain the repaired hair.

[0095] Application Comparative Example 1:

[0096] The damaged hair repair method specifically comprises the following steps:

[0097] (1) Sodium hyaluronate fumarate was prepared according to the method of Example 1;

[0098] (2) 0.5 g of sodium hyaluronate fumarate and 99.5 g of deionized water were stirred and dissolved, and triethanolamine was added to adjust the pH to 3.0 to obtain a 0.5% wt repair agent solution;

[0099] (3) Weigh 0.5 g of damaged hair (damaged hair is homemade to simulate the perm process) and soak it in the repair solution. Set the reaction temperature to 40°C and the reaction time to 15 min. Take it out and dry it to obtain the repaired hair.

[0100] Application Comparative Example 2:

[0101] The damaged hair repair method specifically comprises the following steps:

[0102] (1) Sodium hyaluronate fumarate was prepared according to the method of Example 1;

[0103] (2) 0.5 g of sodium hyaluronate fumarate and 99.5 g of deionized water were stirred and dissolved without adding triethanolamine to adjust the pH to about 4.0, to obtain a 0.5% wt repair agent solution;

[0104] (3) Weigh 0.5 g of damaged hair (damaged hair is homemade to simulate the perm process) and soak it in the repair solution at 40°C for 15 minutes. Take it out and dry it to obtain the repaired hair.

[0105] Application Comparative Example 3:

[0106] The damaged hair repair method specifically comprises the following steps:

[0107] (1) Sodium hyaluronate fumarate was prepared according to the method of Example 1;

[0108] (2) 0.5 g of sodium hyaluronate fumarate and 99.5 g of deionized water were stirred and dissolved, and triethanolamine was added to adjust the pH to 9.0 to obtain a 0.5% wt repair agent solution;

[0109] (3) Weigh 0.5 g of damaged hair (damaged hair is homemade to simulate the perm process) and soak it in the repair solution at 40°C for 15 minutes. Take it out and dry it to obtain the repaired hair.

[0110] Application Comparative Example 4:

[0111] The damaged hair repair method specifically comprises the following steps:

[0112] (1) Sodium hyaluronate fumarate was prepared according to the method of Example 1;

[0113] (2) 0.05 g of sodium hyaluronate fumarate and 99.95 g of deionized water were stirred and dissolved, and triethanolamine was added to adjust the pH to 7.0 to obtain a 0.05 wt% repair agent solution;

[0114] (3) Weigh 0.5 g of damaged hair (damaged hair is homemade to simulate the perm process) and soak it in the repair solution at 40°C for 15 minutes. Take it out and dry it to obtain the repaired hair.

[0115] Application Comparative Example 5:

[0116] The damaged hair repair method specifically comprises the following steps:

[0117] (1) Sodium hyaluronate fumarate was prepared according to the method of Example 1;

[0118] (2) 0.5 g of sodium hyaluronate fumarate and 99.5 g of deionized water were stirred and dissolved, and triethanolamine was added to adjust the pH to 7.0 to obtain a 0.5 wt% repair agent solution;

[0119] (3) Weigh 0.5 g of damaged hair (damaged hair is homemade to simulate the perm process) and soak it in the repair solution at 40°C for 1 min. Take it out and dry it to obtain the repaired hair.

[0120] Application Comparative Example 6:

[0121] The damaged hair repair method specifically comprises the following steps:

[0122] Hair Strand Repair with Fumaric Acid:

[0123] (1) 0.5 g of fumaric acid and 99.5 g of deionized water were stirred and dissolved, and triethanolamine was added to adjust the pH to 7.0 to obtain a 0.5 wt% repair agent solution;

[0124] (2) Weigh 0.5 g of damaged hair (damaged hair is homemade to simulate the perm process) and soak it in the repair solution at 40°C for 15 minutes. Take it out and dry it to obtain the repaired hair.

[0125] Application Comparative Example 7:

[0126] The damaged hair repair method specifically comprises the following steps:

[0127] (1) 0.5 g of sodium hyaluronate (370 kDa) and 99.5 g of deionized water were stirred and dissolved, and triethanolamine was added to adjust the pH to 7.0 to obtain a 0.5 wt% repair agent solution;

[0128] (2) Weigh 0.5 g of damaged hair (damaged hair is homemade to simulate the perm process) and soak it in the repair solution at 40°C for 15 minutes. Take it out and dry it to obtain the repaired hair.

[0129] Test example:

[0130] (1) Study on resident performance:

[0131] The penetration and retention properties of sodium hyaluronate fumarate were determined using the following test methods:

[0132] 1) Preparation of sodium hyaluronate fumarate-FITC fluorescent marker, the specific method is as follows:

[0133] Place 0.2g of sodium hyaluronate fumarate in a stoppered test tube, add 2mL of 0.05mol / L aqueous NaOH solution, seal the tube with a stopper, and vortex for 20 minutes to dissolve the sodium hyaluronate fumarate. Accurately add 0.04g of fluorescein isothiocyanate (FITC) to the test tube, seal the tube with a stopper, and mix thoroughly using a vortex mixer again. Place the tube in a 95°C water bath and maintain the temperature for 45 minutes. Remove the tube and cool to room temperature. Add 18mL of anhydrous ethanol saturated with sodium chloride to the resulting mixture, centrifuge, and discard the supernatant. The resulting precipitate is the crude FITC-labeled sodium hyaluronate fumarate.

[0134] Add 20 mL of anhydrous ethanol solution saturated with sodium chloride to the crude product, vortex mix, and evenly disperse the labeled sodium hyaluronate fumarate precipitate in the anhydrous ethanol solution saturated with sodium chloride. Centrifuge and discard the upper alcohol solution. Repeat the alcohol washing 6 times, collect the precipitate, and freeze-dry to obtain sodium hyaluronate fumarate-FITC fluorescent marker.

[0135] 2) The penetration performance test of sodium hyaluronate fumarate is as follows:

[0136] Damaged hair strands were used for the experiment. 0.05g of sodium hyaluronate fumarate-FITC fluorescent marker was precisely measured and placed in a stoppered test tube. 10mL of deionized water was added, sealed, and vortexed to dissolve. Twenty randomly selected hair strands were immersed in the fluorescently labeled sodium hyaluronate fumarate solution. After soaking for 4 hours, the strands were removed and thoroughly washed to remove any residual sodium hyaluronate fumarate. Finally, cross-sections of the hair strands were obtained using cryosectioning and observed using a fluorescence microscope.

[0137] The above experiment was repeated using underivatized sodium hyaluronate, and the resulting hair tresses were washed multiple times to examine the retention of sodium hyaluronate or sodium hyaluronate derivatives. The washing method simulated daily cleansing, using 0.2g of shampoo per gram of hair tress. After 5 minutes, the sample was rinsed with warm water. Each warm water rinse was followed by ten strokes of the hair with a similar force. The hair was then air-dried under constant temperature and humidity conditions. This was considered one wash cycle, and the washing cycle was repeated seven times.

[0138] Fluorescence penetration properties of hyaluronic acid and sodium hyaluronate fumarate Figure 1 As shown by Figure 1 It can be seen that the molecule prepared in Example 1 has a good retention effect on the hair surface and can still significantly reside on the hair surface after multiple washings, while ordinary sodium hyaluronate basically does not reside on the hair after multiple washings.

[0139] (2) Tensile properties test:

[0140] The tensile properties of hair tresses treated with the different methods described above were tested using the following method: The diameter of the hair strands was measured using an SN-1200W high-definition camera, with the average of the diameters at three locations in the middle of the strands taken. A fiber strength tester was used to test the single-fiber strength of 30 hair strands with a diameter difference within 10 μm from 15 of the differently treated strands. The tensile strength of the hair in the control group and each sample group was calculated and compared using the following formula:

[0141] σ=F b / S o

[0142] Where: σ is the tensile strength, F b is the maximum force that the sample withstands when it breaks, S o is the original cross-sectional area of the specimen. Furthermore, the average elastic modulus of the hair strands was calculated using the elastic modulus area of the tensile curve. The results of the hair tensile strength test are shown in Table 1 below.

[0143] Table 1 Comparison of mechanical properties of different hair bundles

[0144]

[0145]

[0146] As shown in Table 2, the application examples significantly improved the mechanical properties of hair, while the application of comparative examples 1-6 failed to achieve a repairing effect due to inappropriate application conditions. Comparative example 7 also had an improving effect, but not as pronounced as that of application examples 1-4, indicating that derivatized sodium hyaluronate is more effective in improving the mechanical properties of hair than underivatized sodium hyaluronate.

[0147] (3) Hair combing performance test

[0148] The specific test steps are as follows:

[0149] Three identical slightly damaged human hair wigs were selected (soaked in 2% wt thioglycolic acid for 30 min). After drying, the combing work of the three hair wigs was tested using a combing instrument. Each hair wig was combed 10 times, and the combing work value was recorded as the initial combing work.

[0150] The hair was repaired according to the conditions of the application example and the comparative example. After drying, the combing work of three hair bundles was tested using a combing instrument. Each bundle was combed 10 times, and the combing work value was recorded as the repair combing work.

[0151] After conditioning, the hair was washed to simulate daily cleansing, using 0.2g of shampoo per gram of hair, or a dosage consistent with the sample's usage instructions. After 5 minutes, the hair was rinsed with warm water. Each warm water rinse was followed by 10 hand-combing strokes with similar force. The hair was then air-dried under constant temperature and humidity conditions. This process was repeated 15 times to simulate a one-month shampooing cycle. After drying, the combing work of three hair tresses was measured using a combing machine, with each tress combed 10 times. The combing work value was recorded as the retained combing work. The results of the hair combing work test are shown in Table 2 below.

[0152] Table 2 Comparison of combing work of different hair bundles

[0153]

[0154]

[0155] The above results show that Application Examples 1-4 have a good effect on restoring hair combing performance, with combing work significantly reduced after use. Furthermore, good combing performance is maintained even after multiple washes. However, the combing performance of Comparative Examples 1-6 is significantly worse, and Comparative Example 7 also has relatively low combing work, indicating that sodium hyaluronate itself can improve hair combing performance. However, after multiple washes, the combing work significantly increases, indicating that underivatized sodium hyaluronate does not have a long-lasting effect, and therefore the combing performance-enhancing effect is lost with washing.

[0156] The above description is merely a preferred embodiment of the present invention, and the present invention is not limited to the above embodiment. It is understood that other improvements and variations directly derived or imagined by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the scope of protection of the present invention.

Claims

1. A use of a sodium hyaluronate derivative in hair repair, characterized in that: The sodium hyaluronate derivative reacts with the free thiol groups of the hair through Michael addition reaction to achieve retention in the hair and improve the mechanical properties of the hair; The structural formula of the sodium hyaluronate derivative is as follows: R1 includes -CH=CH2, -C(CH3)=CH2, -CH=CH-COOH, -CH=CH-CH3, -CH=CH-CH2CH3 or One of the following; The molecular weight of the sodium hyaluronate is 42kDa-1460kD.

2. The use of the sodium hyaluronate derivative in hair repair according to claim 1, characterized in that: The preparation method of the sodium hyaluronate derivative is: (1) Dissolving sodium hyaluronate to obtain a sodium hyaluronate solution; adding tetrahydrofuran and stirring evenly, then adding triethanolamine and 4-dimethylaminopyridine and stirring to obtain a reaction solution I; (2) After mixing the organic acid and tetrahydrofuran, triethanolamine and 2,4,6-trichlorobenzoyl chloride were added in sequence, and stirred to react to obtain reaction solution II; (3) Adding reaction solution II to reaction solution I of step (1), stirring to react, obtaining a reaction mixture, adding saturated sodium chloride aqueous solution to precipitate and separate the crude product, and then washing; allowing to settle, finally pouring out the clear liquid, and drying the precipitate to obtain a sodium hyaluronate derivative; In step (2), the organic acid includes one or more of fumaric acid, maleic acid, acrylic acid, methacrylic acid, 2-butenoic acid, 2-pentenoic acid, and shikimic acid.

3. The use according to claim 2, characterized in that In step (1), the mass fraction of the sodium hyaluronate solution is 1-10%.

4. The use according to claim 2, characterized in that In step (1), the mass volume ratio of sodium hyaluronate to tetrahydrofuran (g / mL) is 2-5:50; the mass volume ratio of sodium hyaluronate to triethanolamine (g / mL) is 5:3.5-4; and the mass ratio of sodium hyaluronate to 4-dimethylaminopyridine is 5:0.010-0.

015.

5. The use according to claim 2, characterized in that In step (2), the mass volume ratio of the organic acid to tetrahydrofuran (g / mL) is 1-5:50; the molar ratio of the organic acid to triethanolamine is 0.5-1:1; and the molar ratio of the organic acid to 2,4,6-trichlorobenzoyl chloride is 0.5-1:

1.

6. The use according to claim 2, characterized in that In step (3), the mass ratio of the organic acid in the reaction solution II to the sodium hyaluronate in the reaction solution I is 0.05-0.075:

1.

7. The use according to claim 2, characterized in that In step (3), the volume ratio of the saturated sodium chloride solution to the reaction mixture is 4-5:1.

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