Sunproof real silk fabric based on modified curcumin and preparation method thereof

Abstract

The invention relates to a sun-proof real silk fabric based on modified curcumin and a preparation method of the sun-proof real silk fabric, and belongs to the technical field of dyeing and finishing. The preparation method comprises the following steps: S1, under the action of a catalyst, baicalin and dihydropyran are subjected to an etherification reaction in water, and etherified baicalin is obtained; s2, carrying out an activation reaction on the etherified baicalin and an activating agent in a solvent, and then continuously adding curcumin to carry out an esterification reaction, so as to obtain modified curcumin; s3, dissolving the modified curcumin in water to obtain finishing liquid, and soaking the real silk fabric in the finishing liquid for dyeing to obtain the sun-proof real silk fabric based on the modified curcumin. The baicalin is adopted to modify curcumin molecules, so that the problems that curcumin is weak in ultraviolet protection capability and the light fastness of the dyed real silk fabric is poor are solved, and a safe and environment-friendly solution is provided for improving the light fastness of the natural dye dyed real silk fabric.

Description

Technical Field

[0001] The invention belongs to the technical field of dyeing and finishing, and in particular relates to a light-fast silk fabric based on modified curcumin and a preparation method thereof. Background Art

[0002] At present, the textile industry is facing many problems such as the restriction or ban of the use of some toxic and harmful reagents and environmental pollution. The textile industry urgently needs to establish an ecologically sustainable dyeing and finishing system. Most natural dyes have good biodegradability, less impact on the environment, and have certain functionalities such as antibacterial properties and ultraviolet protection properties. Therefore, compared with synthetic dyes, they have more advantages and application prospects. However, there are still many problems with natural dyes in the printing and dyeing process of textiles, such as incomplete color spectrum, high cost, and poor color fastness.

[0003] Curcumin is a natural dye extracted from the rhizome of the plant turmeric. It has a high color value and dyeing ability among natural dyes and is one of the most industrialized natural dyes in the field of textile processing. In existing studies, curcumin not only gives excellent dyeing properties to polyester and acrylic fibers, but also has been widely used in the antibacterial functional finishing of wool, silk and nylon due to its excellent antibacterial properties. However, the poor photostability of curcumin hinders its large-scale printing and dyeing processing on textiles. This is because the electron cloud density of the conjugated system of the diketone structure in the curcumin molecule is high, and it absorbs light energy under light conditions, the energy level increases, and it is easy to undergo oxidation reactions, causing its color system to be destroyed and faded. For this reason, the prior art often uses organic reagents such as sodium borohydride and p-aminobenzenesulfonic acid as raw materials to modify curcumin. Although the water solubility of the modified curcumin is greatly improved, the light fastness is still poor, and the organic reagents are highly toxic, there are certain safety hazards, and it does not conform to the concept of ecological textiles and green textile industry. In addition, when silk is dyed and finished, although silk contains many reducing groups such as amino, imino and hydroxyl groups, the tryptophan in silk has the ability to sensitize singlet oxygen under visible light, causing the dye on the silk to fade by photooxidation.

[0004] Therefore, there is an urgent need to improve the UV protection and antioxidant properties of curcumin through chemical modification to enhance the photostability of curcumin itself, so that it can be used to prepare silk fabrics with sun-resistant properties. Summary of the invention

[0005] To this end, the technical problem to be solved by the present invention is to overcome the problems in the prior art that the curcumin-dyed silk fabric has poor sunlight fastness and the curcumin-modified raw materials have potential safety hazards.

[0006] In order to solve the above technical problems, the present invention provides a light-fast silk fabric based on modified curcumin and a preparation method thereof, utilizing the light fading mechanism of curcumin and the ultraviolet absorption performance and antioxidant performance of baicalin, and without introducing any additional substances that increase the environmental burden, using baicalin to modify the curcumin molecule, thereby improving the problems of weak ultraviolet protection ability of curcumin and poor light fastness of dyed silk fabrics, and providing a safe and environmentally friendly solution for improving the light fastness of silk fabrics dyed with natural dyes.

[0007] The first object of the present invention is to provide a method for preparing a light-fast silk fabric based on modified curcumin, comprising the following steps:

[0008] S1. Under the action of a catalyst, baicalin and dihydropyran undergo an etherification reaction in water to obtain etherified baicalin;

[0009] S2, the etherified baicalin and the activator described in S1 are activated in a solvent, and then curcumin is added to carry out an esterification reaction to obtain modified curcumin;

[0010] S3, dissolving the modified curcumin described in S2 in water to obtain a finishing solution, and immersing the silk fabric in the finishing solution for dyeing to obtain the light-fast silk fabric based on the modified curcumin.

[0011] In one embodiment of the present invention, in S1, the catalyst is aluminum phosphate.

[0012] In one embodiment of the present invention, in S1, the molar ratio of baicalin, dihydropyran and catalyst is 1:(5-5.5):(0.0075-0.015).

[0013] In one embodiment of the present invention, in S1, the pH of the etherification reaction is 3-4, the temperature is 85°C-95°C, and the time is 20min-40min. The purpose of the etherification reaction is to prevent N,N-carbonyldiimidazole from activating the phenolic hydroxyl group and the carboxyl group on baicalin at the same time to form a cyclic compound.

[0014] In one embodiment of the present invention, in S2, the activator is N,N-carbonyldiimidazole;

[0015] The solvent is dimethyl sulfoxide.

[0016] In one embodiment of the present invention, in S2, the molar ratio of curcumin, etherified baicalin and activator is (1:2:2)-(2:3:3).

[0017] In one embodiment of the present invention, in S2, the activation reaction temperature is 60°C-80°C, and the time is 4h-6h;

[0018] The temperature of the esterification reaction is 60° C.-80° C., and the time is 36 h-72 h.

[0019] In one embodiment of the present invention, in S3, the concentration of the modified curcumin in the finishing liquid is 5wt%-7wt%.

[0020] In one embodiment of the present invention, in S3, the dyeing process is: bath ratio is 1: (30-50), pH is 5-6, temperature is 85°C-95°C, and time is 50min-70min.

[0021] The second object of the present invention is to provide a light-fast silk fabric based on modified curcumin prepared by the preparation method.

[0022] The technical solution of the present invention has the following advantages over the prior art:

[0023] (1) The preparation method of the present invention connects curcumin and baicalin through an esterification reaction, and the phenolic hydroxyl groups on the baicalin molecules are not destroyed. The modified curcumin releases the hydrogen atoms of the phenolic hydroxyl groups and generates stable semiquinone free radicals, thereby terminating the occurrence of free radical chain reactions and achieving antioxidant effects.

[0024] (2) The preparation method of the present invention uses baicalin to directly modify the curcumin molecule, and the final product does not introduce other molecules except baicalin. The reaction conditions are mild, the energy consumption is low, and the toxicity is low. That is, only natural products are used to make up for the problem of poor light fastness on textiles, which provides a safe and environmentally friendly solution for improving the light fastness of curcumin-dyed silk fabrics.

[0025] (3) The modified curcumin in the light-fast silk fabric based on modified curcumin described in the present invention is a natural dye. Curcumin and etherified baicalin are connected by esterification reaction, which reduces the burden on the environment. The modified curcumin has good sunlight fastness on the silk fabric. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0027] Figure 1 The modified curcumin synthesis route diagram of the modified curcumin of Example 1 of the present invention;

[0028] Figure 2 is the infrared absorption spectrum of baicalin before and after etherification in Test Example 1 of the present invention;

[0029] Figure 3 The infrared absorption spectra of curcumin before and after modification of Test Example 1 of the present invention;

[0030] Figure 4 This is a comparison diagram of silk fabrics dyed with different dyes before and after sun exposure in Test Example 3 of the present invention;

[0031] Figure 5 This is a graph showing the variation of K / S values ​​of silk fabrics dyed with different concentrations of curcumin and modified curcumin as a function of exposure time in Test Example 4 of the present invention;

[0032] Figure 6 The figures are comparison diagrams of different concentrations of curcumin and modified curcumin on silk fabrics dyed with the sun before and after exposure in Test Example 4 of the present invention. DETAILED DESCRIPTION

[0033] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. It should be understood that the specific embodiments are only used to explain the present invention, but the embodiments are not intended to limit the present invention.

[0034] In the present invention, unless otherwise explained, technical and scientific terms used in the present invention have the same meanings as commonly understood by those skilled in the art to which the present invention belongs.

[0035] In the present invention, unless otherwise stated, the term "and / or" used in the present invention includes any and all combinations of one or more of the associated listed items.

[0036] In the present invention, unless otherwise stated, the experimental methods used in the embodiments of the present invention are conventional methods unless otherwise stated, and the materials, reagents, etc. used are all commercially available unless otherwise stated.

[0037] Example 1

[0038] Reference Figure 1 As shown, the light-fast silk fabric based on modified curcumin and the preparation method thereof of this embodiment specifically include the following steps:

[0039] S1. Dissolve 0.25 g of baicalin in 30 mL of deionized water, add 0.2 g of dihydropyran and 0.01 g of aluminum phosphate, adjust the pH to 3 with acetate buffer, and place the solution in a 90° C. shaking water bath to react for 30 min; after the solution is cooled, centrifuge and wash with water at a speed of 4000 r / min for 10 min, centrifuge and wash with water 3 times to remove unreacted dihydropyran, and then filter and dry to obtain etherified baicalin powder.

[0040] S2. Dissolve 0.17 g of etherified baicalin powder in 10 mL of dimethyl sulfoxide, add 0.06 g of N,N-carbonyldiimidazole, and react at 70°C for 5 h; after the reaction, add curcumin dimethyl sulfoxide solution (0.07 g of curcumin is dissolved in 10 mL of dimethyl sulfoxide) and continue the reaction for 48 h; after the reaction, pour the reaction solution into a separatory funnel, add 100 mL of deionized water and 20 mL of dichloromethane, shake well, release air, and extract at rest. Take the lower layer of extract and distill it at 40°C to obtain modified curcumin.

[0041] S3, dissolving the modified curcumin in water to prepare a finishing solution with a concentration of 5wt%, and immersing the silk fabric in the finishing solution for dyeing to obtain a light-fast silk fabric based on modified curcumin; wherein the dyeing process is: the bath ratio is 1:50, the pH is adjusted to 5.6 with acetate buffer, dyeing is started at room temperature, and the temperature is raised to 90°C at a rate of 2°C / min for dyeing for 60 minutes.

[0042] Example 2

[0043] The light-fast silk fabric based on modified curcumin and the preparation method thereof of this embodiment specifically include the following steps:

[0044] S1. Dissolve 0.5 g of baicalin in 30 mL of deionized water, add 0.47 g of dihydropyran and 0.001 g of aluminum phosphate, adjust the pH to 3.4 with acetate buffer, and place the solution in a 90° C. shaking water bath to react for 30 min; after the solution is cooled, centrifuge and wash with water at a speed of 4000 r / min for 10 min, centrifuge and wash with water 3 times to remove unreacted dihydropyran, and then filter and dry to obtain etherified baicalin powder.

[0045] S2. Dissolve 0.32 g of etherified baicalin powder in 20 mL of dimethyl sulfoxide, add 0.12 g of N,N-carbonyldiimidazole, and react at 60°C for 6 h; after the reaction, add curcumin dimethyl sulfoxide solution (0.14 g of curcumin is dissolved in 10 mL of dimethyl sulfoxide) and continue the reaction for 36 h; after the reaction, pour the reaction solution into a separatory funnel, add 150 mL of deionized water and 30 mL of dichloromethane, shake well, release air, and extract at rest. Take the lower layer of extract and distill it at 40°C to obtain modified curcumin.

[0046] S3, dissolving the modified curcumin in water to prepare a finishing solution with a concentration of 6wt%, and immersing the silk fabric in the finishing solution for dyeing to obtain a light-fast silk fabric based on modified curcumin; wherein the dyeing process is: the bath ratio is 1:50, the pH is adjusted to 5.6 with acetate buffer, dyeing is started at room temperature, and the temperature is raised to 90°C at a rate of 2°C / min for dyeing for 60min.

[0047] Example 3

[0048] The light-fast silk fabric based on modified curcumin and the preparation method thereof of this embodiment specifically include the following steps:

[0049] S1. Dissolve 1 g of baicalin in 50 mL of deionized water, add 0.95 g of dihydropyran and 0.015 g of aluminum phosphate, adjust the pH to 3.6 with acetate buffer, and place the solution in a 90° C. shaking water bath to react for 30 min; after the solution is cooled, centrifuge and wash with water at a speed of 4000 r / min for 10 min, centrifuge and wash with water 3 times to remove unreacted dihydropyran, and then filter and dry to obtain etherified baicalin powder.

[0050] S2. Dissolve 0.824 g of etherified baicalin powder in 10 mL of dimethyl sulfoxide, add 0.32 g of N,N-carbonyldiimidazole, and react at 80°C for 4 h; after the reaction, add curcumin dimethyl sulfoxide solution (0.4 g of curcumin is dissolved in 10 mL of dimethyl sulfoxide), and continue the reaction for 36 h; after the reaction, pour the reaction solution into a separatory funnel, add 200 mL of deionized water and 20 mL of dichloromethane, shake well, release air, and extract at rest. Take the lower layer of extract and distill it at 40°C to obtain modified curcumin.

[0051] S3, dissolving the modified curcumin in water to prepare a finishing solution with a concentration of 7wt%, and immersing the silk fabric in the finishing solution for dyeing to obtain a light-fast silk fabric based on modified curcumin; wherein the dyeing process is: the bath ratio is 1:50, the pH is adjusted to 5.6 with acetate buffer, dyeing is started at room temperature, and the temperature is raised to 90°C at a rate of 2°C / min for dyeing for 60min.

[0052] Example 4

[0053] The light-fast silk fabric based on modified curcumin and the preparation method thereof of this embodiment specifically include the following steps:

[0054] S1. Dissolve 2 g of baicalin in 50 mL of deionized water, add 2 g of dihydropyran and 0.03 g of aluminum phosphate, adjust the pH to 4 with acetate buffer, and place the solution in a 90° C. shaking water bath to react for 30 min; after the solution is cooled, centrifuge and wash with water at a speed of 4000 r / min for 10 min, centrifuge and wash with water 3 times to remove unreacted dihydropyran, and then filter and dry to obtain etherified baicalin powder.

[0055] S2. Dissolve 1.64 g of etherified baicalin powder in 10 mL of dimethyl sulfoxide, add 0.65 g of N,N-carbonyldiimidazole, and react at 80°C for 4 h; after the reaction, add curcumin dimethyl sulfoxide solution (0.8 g of curcumin is dissolved in 10 mL of dimethyl sulfoxide), and continue the reaction for 72 h; after the reaction, pour the reaction solution into a separatory funnel, add 300 mL of deionized water and 20 mL of dichloromethane, shake well, release air, and extract at rest. Take the lower layer of extract and distill it at 40°C to obtain modified curcumin.

[0056] S3, dissolving the modified curcumin in water to prepare a finishing solution with a concentration of 5wt%, and immersing the silk fabric in the finishing solution for dyeing to obtain a light-fast silk fabric based on the modified curcumin; wherein the dyeing process is: the bath ratio is 1:50, the pH is adjusted to 5.6 with an acetate buffer, the dyeing is carried out at a constant temperature of 90°C, and the dyeing is carried out for 60 minutes.

[0057] Example 5

[0058] The light-fast silk fabric based on modified curcumin and the preparation method thereof of this embodiment specifically include the following steps:

[0059] S1. Dissolve 1 g of baicalin in 50 mL of deionized water, add 0.95 g of dihydropyran and 0.015 g of aluminum phosphate, adjust the pH to 3.6 with acetate buffer, and place the solution in a 90° C. shaking water bath to react for 30 min; after the solution is cooled, centrifuge and wash with water at a speed of 4000 r / min for 10 min, centrifuge and wash with water 3 times to remove unreacted dihydropyran, and then filter and dry to obtain etherified baicalin powder.

[0060] S2. Dissolve 0.824 g of etherified baicalin powder in 10 mL of dimethyl sulfoxide, add 0.32 g of N,N-carbonyldiimidazole, and react at 80°C for 4 h; after the reaction, add curcumin dimethyl sulfoxide solution (0.4 g of curcumin is dissolved in 10 mL of dimethyl sulfoxide), and continue the reaction for 36 h; after the reaction, pour the reaction solution into a separatory funnel, add 200 mL of deionized water and 20 mL of dichloromethane, shake well, release air, and extract at rest. Take the lower layer of extract and distill it at 40°C to obtain modified curcumin.

[0061] S3, dissolving the modified curcumin in water to prepare a finishing solution with a concentration of 5wt%, and immersing the silk fabric in the finishing solution for dyeing to obtain a light-fast silk fabric based on the modified curcumin; wherein the dyeing process is: the bath ratio is 1:50, the pH is adjusted to 5.6 with an acetate buffer, the dyeing is carried out at a constant temperature of 90°C, and the dyeing is carried out for 60 minutes.

[0062] Comparative Example 1

[0063] The method is basically the same as Example 5, except that baicalin is not subjected to etherification treatment.

[0064] Comparative Example 2

[0065] The method is basically the same as Example 5, except that N,N-carbonyldiimidazole is not used for activation.

[0066] Comparative Example 3

[0067] The method is basically the same as Example 5, except that the molar ratio of baicalin to dihydropyran is changed from 1:5 to 1:10.

[0068] Comparative Example 4

[0069] Basically the same as Example 5, except that baicalin is replaced by quercetin.

[0070] Test Example 1

[0071] (1) Based on Example 5, infrared spectroscopy was performed on baicalin before and after etherification. The results are as follows: Figure 2 As shown. Figure 2 It can be seen that the etherified baicalin has a wavelength of 1111 cm -1 The absorption peak of the new ether bond at wave number 1068cm -1 The hydroxyl absorption peak at baicalin becomes weaker, indicating that the hydroxyl group on baicalin is protected.

[0072] (2) Based on Example 5, infrared spectroscopy was performed on curcumin before and after modification. The results are as follows Figure 3 As shown. Figure 3 It can be seen that the curcumin before modification has a wave number of 3500 cm -1 There is a sharp -OH stretching vibration absorption peak around 1750cm, while the corresponding peak of the modified curcumin basically disappears at this wave number, indicating that the hydroxyl group in curcumin has reacted. -1 An ester bond absorption peak appears nearby, indicating that an esterification reaction occurs between baicalin and curcumin.

[0073] Test Example 2

[0074] Color characteristics: measured using HunterLab UltraScan PRO reflectance spectrophotometer.

[0075] Color fastness: Tested according to GB / T 8427-2019 "Textiles - Tests for color fastness - Color fastness to artificial light: Xenon arc fading lamp".

[0076] The light fastness test of the light-fast silk fabrics based on modified curcumin of Examples 1-5 and Comparative Examples 1-4 was carried out for 20 hours, and the results are shown in Table 1.

[0077] Table 1 shows the relevant performance parameters of the silk fabric finally measured:

[0078] Table 1

[0079]

[0080]

[0081] It can be seen from Table 1 that the light-fast silk fabric based on modified curcumin in the examples has excellent light fastness.

[0082] Comparison of Example 5 and Comparative Example 1 shows that baicalin in Comparative Example 1 is not etherified and does not react with curcumin. This is because the hydroxyl groups on the baicalin molecule are not effectively protected due to the lack of the etherification reactant dihydropyran, and the hydroxyl and carboxyl groups of baicalin itself react under the activation of N,N-carbonyldiimidazole to form a cyclic compound. The final product is a blended powder of activated baicalin and curcumin, and the light fastness of the dyed silk fabric is not improved.

[0083] By comparing Example 5 and Comparative Example 2, it can be seen that in Comparative Example 2, the activator N,N-carbonyldiimidazole was not added, baicalin and curcumin did not react, the final product was a blended powder of baicalin and curcumin, and the light fastness of the dyed silk fabric was not improved.

[0084] By comparing Example 5 and Comparative Example 3, it can be seen that the proportion of dihydropyran in Comparative Example 3 is too much, the activation rate of baicalin by N, N-carbonyldiimidazole is accelerated and does not react with curcumin. Due to the excessive amount of dihydropyran, the carboxyl group on baicalin is destroyed, and after being activated by N, N-carbonyldiimidazole, it becomes cyclic and does not undergo esterification reaction with curcumin. The final product is a blended powder of activated baicalin and curcumin, and the light fastness of the dyed silk fabric is not improved.

[0085] By comparing Example 5 and Comparative Example 4, it can be seen that the light fastness of the silk fabric prepared by quercetin-modified curcumin in Comparative Example 4 is not effectively improved, because quercetin and curcumin do not react under this condition.

[0086] Test Example 3

[0087] Based on Test Example 5, the light fastness of silk fabrics dyed with different dyes (curcumin, baicalin, blend of curcumin and baicalin, and modified curcumin) was investigated. The results are as follows: Figure 4 And as shown in Table 2.

[0088] Figure 4 This is a real picture before and after sun exposure (the middle part is sun-exposed, and the two sides are not sun-exposed);

[0089] Table 2 shows the relevant performance parameters of the silk fabric finally measured:

[0090] Table 2

[0091] dye Curcumin Baicalin Curcumin and baicalin blend Modified Curcumin Wavelength (nm) 420 420 420 420 Before sun exposure (K / S) 23.987 0.437 26.445 13.012 After sun (K / S) 3.080 0.271 3.196 7.450 Decline rate (%) 87.16 37.84 87.91 42.74

[0092] From Table 2 and Figure 4 It can be seen that baicalin dyed colorless; baicalin and curcumin blended did not improve the light fastness of dyed silk fabrics, and the degree of fading after sun exposure was almost the same as that of curcumin alone dyed silk fabrics, indicating that baicalin and curcumin blended dyeing is only a competitive dyeing relationship. The K / S reduction rate of silk fabrics dyed with modified curcumin was 42.74%, which was half of the K / S reduction rate of silk fabrics dyed with curcumin. This shows that the use of baicalin to modify curcumin has greatly improved the light fastness of silk fabrics dyed with modified curcumin, providing a green and environmentally friendly solution for improving the light fastness of curcumin-dyed fabrics.

[0093] Test Example 4

[0094] Based on Test Example 5, the light fastness of silk fabrics dyed with curcumin solutions and modified curcumin solutions of different concentrations (1wt%, 5wt%, 10wt%) was investigated, and the K / S value changes were as follows: Figure 5 , the actual picture before and after sun exposure (the middle part is sun-exposed, and the two sides are not sun-exposed) is as follows Figure 6 As shown. Figure 5-Figure 6 It can be seen that the K / S value of silk fabric dyed with unmodified curcumin decreases more and more obviously with the increase of sun exposure time; the K / S value of silk fabric dyed with modified curcumin decreases significantly after 4 hours of sun exposure, and the K / S value hardly decreases with continued sun exposure. This is because the modified curcumin contains a certain amount of baicalin, which releases phenolic hydroxyl hydrogen atoms to make the modified curcumin obtain antioxidant effect, and at the same time generates stable semiquinone free radicals, terminating the occurrence of free radical chain reaction, thereby achieving antioxidant effect. This also shows that the use of baicalin to modify curcumin can effectively improve the light fastness of dyed silk fabrics.

[0095] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A method for preparing a light-fast silk fabric based on modified curcumin, characterized in that: The following steps are involved: S1. Under the action of a catalyst, baicalin and dihydropyran undergo an etherification reaction in water to obtain etherified baicalin; S2, the etherified baicalin and the activator described in S1 are activated in a solvent, and then curcumin is added to carry out an esterification reaction to obtain modified curcumin; S3, dissolving the modified curcumin described in S2 in water to obtain a finishing solution, and immersing the silk fabric in the finishing solution for dyeing to obtain the light-fast silk fabric based on the modified curcumin.

2. The method for preparing a light-fast silk fabric based on modified curcumin according to claim 1, characterized in that: In S1, the catalyst is aluminum phosphate.

3. The method for preparing a light-fast silk fabric based on modified curcumin according to claim 1, characterized in that: In S1, the molar ratio of baicalin, dihydropyran and catalyst is 1:(5-5.5):(0.0075-0.015).

4. The method for preparing a light-fast silk fabric based on modified curcumin according to claim 1, characterized in that: In S1, the pH of the etherification reaction is 3-4, the temperature is 85°C-95°C, and the time is 20min-40min.

5. The method for preparing light-fast silk fabric based on modified curcumin according to claim 1, characterized in that: In S2, the activator is N,N-carbonyldiimidazole; The solvent is dimethyl sulfoxide.

6. The method for preparing light-fast silk fabric based on modified curcumin according to claim 1, characterized in that: In S2, the molar ratio of curcumin, etherified baicalin and activator is (1:2:2)-(2:3:3).

7. The method for preparing light-fast silk fabric based on modified curcumin according to claim 1, characterized in that: In S2, the activation reaction temperature is 60°C-80°C, and the time is 4h-6h; The temperature of the esterification reaction is 60° C.-80° C., and the time is 36 h-72 h.

8. The method for preparing light-fast silk fabric based on modified curcumin according to claim 1, characterized in that: In S3, the concentration of the modified curcumin in the finishing solution is 5wt%-7wt%.

9. The method for preparing light-fast silk fabric based on modified curcumin according to claim 1, characterized in that: In S3, the dyeing process is: bath ratio is 1: (30-50), pH is 5-6, temperature is 85°C-95°C, and time is 50min-70min.

10. A light-fast silk fabric based on modified curcumin prepared by the preparation method according to any one of claims 1 to 9.

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