Modified silk fibroin, preparation method thereof and application of modified silk fibroin in silk product

Abstract

The present application relates to a kind of modified silk fibroin and its preparation method and application in silk product, belong to textile technical field.The present application is modified to silk fibroin using tetramethylammonium phosphonium chloride, polyhexamethylene biguanide, glutaraldehyde, diethyl phosphite, prepare multifunctional modified silk fibroin;Then multifunctional silk product of antibacterial, mildewproof, flame-retardant is prepared by spraying, air-drying mode, and silk product is carried out safety protection.The modified silk fibroin of the present application has good compatibility with silk product such as silk cultural relics, can be adsorbed on silk product, and the hydroxymethyl of tetramethylammonium phosphonium chloride not involved in the reaction on the surface of modified silk fibroin, the aldehyde group of glutaraldehyde can occur crosslinking reaction with the active amino group of silk product, so as to graft modified silk fibroin on silk product, thus can be modified to silk product by spraying, natural air-drying mode.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of textiles, and particularly relates to a modified silk fibroin, a preparation method thereof and application of the modified silk fibroin in silk products. BACKGROUND

[0002] Silk is an ancient textile known as the "Queen of Fibers", and is famous for its soft hand feeling, soft luster, good moisture absorption and ventilation, and comfortable wearing experience. However, silk cultural relics are usually very fragile after being unearthed, and need special protection measures to resist the damage of modern environment. These cultural relics are prone to mold and bacterial growth, and are easy to burn due to poor flame retardant performance. Therefore, the protection and inheritance of silk culture have great significance for cultural exchange and economic development.

[0003] For special silk products such as silk cultural relics, traditional immersion protection methods are not applicable, and spraying and natural air drying methods need to be used for protection. It is of great practical significance to develop a high-efficiency multifunctional finishing liquid integrating antibacterial, mildew-proof and flame-retardant functions, which can effectively protect silk cultural relics through simple spraying.

[0004] At present, quaternary ammonium salt antibacterial agents are commonly used for antibacterial finishing of textiles, but the combination of quaternary ammonium salt antibacterial agents with fabrics is poor. Chinese invention patent CN 109281166A discloses a protein fiber antibacterial finishing method based on enzymatic graft copolymerization, which uses tyrosine phenol-lyase to catalyze the conversion of serine in protein fiber macromolecules into tyrosine, and then uses horseradish peroxidase to catalyze the graft copolymerization of tyrosine in protein fiber with vinyl group-containing quaternary ammonium salt monomers for protein fiber antibacterial finishing. However, this method has a complicated process, and the protein fiber needs to be hydrolyzed, which seriously damages the protein fiber.

[0005] Silk fibroin is a natural high-molecular fibrous protein extracted from silk. It accounts for 70%-80% of the total amount of silk fiber and is a tough and elastic protein. The main components of silk fibroin include glycine, alanine, serine, proline, tyrosine and other amino acids. Due to its unique physical and chemical properties and biocompatibility, silk fibroin has a wide range of applications in many fields. It can not only be used in the textile industry, but also shows great potential in the field of biomedical materials. Silk fibroin has good compatibility with silk products and can adhere to silk products. Reference (Zhang Z B, Li G, Mao S X, et al. Preparation of silk fibroin / chitosan microspheres and their antibacterial properties [J]. Journal of Textile Research, 2019, 40(10): 7-12.) uses emulsion polymerization to prepare silk fibroin / chitosan antibacterial microspheres, but the antibacterial efficiency is low and the flame retardant effect cannot be achieved.

[0006] It is of great significance to develop a multifunctional modified silk fibroin and then prepare an antibacterial and mildew-proof and flame-retardant multifunctional silk product by spraying and air-drying, but there are great challenges. SUMMARY

[0007] To solve the above technical problems, the application provides a modified silk fibroin, a preparation method thereof and application thereof in silk products, first, the silk fibroin is modified by tetramethylammonium phosphate, polyhexamethylene biguanide, glutaraldehyde and diethyl phosphite to prepare a multifunctional modified silk fibroin, then an antibacterial, mildew-proof and flame-retardant multifunctional silk product is prepared by spraying and air-drying, and the silk product is protected.

[0008] The first object of the application is to provide a preparation method of a modified silk fibroin, comprising the following steps: adding tetramethylammonium phosphate, polyhexamethylene biguanide and glutaraldehyde into a silk fibroin solution, then adding a diethyl phosphite solution dropwise to react, to obtain the modified silk fibroin.

[0009] In an embodiment of the application, the mass ratio of the tetramethylammonium phosphate, polyhexamethylene biguanide, glutaraldehyde, diethyl phosphite and silk fibroin is (30-50):(40-60):(10-15):(30-45):(20-30). The hydroxymethyl of the tetramethylammonium phosphate can crosslink with the amino group of the silk fibroin and the amino group of the polyhexamethylene biguanide, and the aldehyde group of the glutaraldehyde can react with the amino group of the silk fibroin and the amino group of the polyhexamethylene biguanide to form a Schiff base, and the active P-H bond of the diethyl phosphite can react with the C=N structure of the Schiff base to form a Pudovik addition reaction, so that the silk fibroin, tetramethylammonium phosphate, polyhexamethylene biguanide, glutaraldehyde and diethyl phosphite are crosslinked to graft on the silk fibroin to prepare the multifunctional modified silk fibroin.

[0010] In an embodiment of the application, the concentration of the silk fibroin solution is 20g / L-30g / L, for example, it can be 20g / L, 21g / L, 22g / L, 23g / L, 24g / L, 25g / L, 26g / L, 27g / L, 28g / L, 29g / L, 30g / L and the like.

[0011] In an embodiment of the present application, the temperature of the reaction is 70-80 DEG C, for example, it can be 70 DEG C, 71 DEG C, 72 DEG C, 73 DEG C, 74 DEG C, 75 DEG C, 76 DEG C, 77 DEG C, 78 DEG C, 79 DEG C, 80 DEG C, etc. The time is 60-90 min, for example, it can be 60 min, 61 min, 62 min, 63 min, 64 min, 65 min, 66 min, 67 min, 68 min, 69 min, 70 min, 71 min, 72 min, 73 min, 74 min, 75 min, 76 min, 77 min, 78 min, 79 min, 80 min, 81 min, 82 min, 83 min, 84 min, 85 min, 86 min, 87 min, 88 min, 89 min, 90 min, etc. Both the increase of the reaction temperature and the extension of the time are helpful to improve the reaction degree, but too high temperature is a waste.

[0012] In an embodiment of the present application, the solvent of the diethyl phosphite solution is ethanol; the mass ratio between the diethyl phosphite and the ethanol is 1: (1-2).

[0013] The second object of the present application is to provide a modified silk fibroin prepared by the method.

[0014] The third object of the present application is to provide a finishing method of multifunctional silk products, comprising the following steps: spraying a modified silk fibroin finishing liquid on the surface of the silk product to obtain the multifunctional silk product after air drying; the modified silk fibroin finishing liquid comprises the modified silk fibroin and water.

[0015] In an embodiment of the present application, the concentration of the modified silk fibroin finishing liquid is 30-50 g / L, for example, it can be 30 g / L, 31 g / L, 32 g / L, 33 g / L, 34 g / L, 35 g / L, 36 g / L, 37 g / L, 38 g / L, 39 g / L, 40 g / L, 41 g / L, 42 g / L, 43 g / L, 44 g / L, 45 g / L, 46 g / L, 47 g / L, 48 g / L, 49 g / L, 50 g / L, etc.

[0016] In an embodiment of the present application, after spraying the modified silk fibroin finishing liquid, the liquid retention rate of the silk product is 30-50%, for example, it can be 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, etc.

[0017] The fourth object of the present application is to provide a multifunctional silk product obtained by the method.

[0018] The technical solution of the present application has the following advantages compared with the prior art:

[0019] (1) The preparation method of the present application adopts the hydroxymethyl of tetramethylphosphonium chloride which can cross-link with the amino group of silk fibroin and polyhexamethylene biguanide, and the aldehyde group of glutaraldehyde which can form Schiff base with the amino group of silk fibroin and polyhexamethylene biguanide, so as to graft the network structure formed by tetramethylphosphonium chloride, polyhexamethylene biguanide and glutaraldehyde on silk fibroin; the active P-H bond of diethyl phosphite can undergo Pudovik addition reaction with the Schiff base C=N structure, so as to graft diethyl phosphite on silk fibroin to prepare multifunctional modified silk fibroin.

[0020] (2) The modified silk fibroin of the present application has good compatibility with silk products such as silk cultural relics, can be adsorbed on the silk product, and the hydroxymethyl of tetramethylphosphonium chloride and the aldehyde group of glutaraldehyde on the surface of the modified silk fibroin which do not participate in the reaction can cross-link with the active amino group of the silk product, so as to graft the modified silk fibroin on the silk product, thus the silk product can be modified by spraying and natural air drying.

[0021] (3) The preparation method of the present application can play an antibacterial and mildew-proof effect through the synergistic effect of tetramethylphosphonium chloride, polyhexamethylene biguanide and glutaraldehyde, and tetramethylphosphonium chloride and diethyl phosphite can act as an acid source, polyhexamethylene biguanide can act as a gas source, and silk fibroin can act as a carbon source, thus an intumescent flame-retardant system is organically constructed, and the flame-retardant efficiency is high. DETAILED DESCRIPTION

[0022] The present application will be further described below in conjunction with specific examples, so that those skilled in the art can better understand the present application and implement it. Obviously, the described examples are only a part of the examples of the present application, but not all the examples. It should be understood that the specific examples are only used to explain the present application, but the examples are not limited to the present application.

[0023] In the present application, unless otherwise specified, the technical and scientific terms used in the present application have the same meaning as those commonly understood by the skilled in the art to which the present application belongs.

[0024] In the present application, unless otherwise specified, the term "and / or" used in the present application includes any and all combinations of one or more related listed items.

[0025] In the present application, unless otherwise specified, the experimental methods used in the embodiments of the present application are conventional methods, and the materials, reagents, etc. used, unless otherwise specified, can be obtained from commercial channels.

[0026] In the present application, unless otherwise specified, the silk fibroin used in the embodiments of the present application is purchased from Huzhou Xintiansi Biotechnology Co., Ltd., and the average particle size is about 350 nm.

[0027] In the present application, unless otherwise specified, the diethyl phosphite solution used in the embodiments of the present application is obtained by mixing diethyl phosphite and ethanol according to a mass ratio of 1:1.5.

[0028] Embodiment 1

[0029] The modified silk fibroin of the present embodiment and its application in silk products specifically include the following steps:

[0030] S1, tetrahydroxymethyl phosphonium chloride, polyhexamethylene biguanide, glutaraldehyde are added to a silk fibroin solution with a concentration of 25 g / L, then a diethyl phosphite solution is added dropwise, and the reaction is carried out at 75℃ for 75 min, and the modified silk fibroin is obtained after filtration and water washing; wherein the amount of tetrahydroxymethyl phosphonium chloride is 40 g / L, the amount of polyhexamethylene biguanide is 50 g / L, the amount of glutaraldehyde is 13 g / L, and the final amount of diethyl phosphite is 38 g / L;

[0031] S2, first disperse the modified silk fibroin in water to prepare a modified silk fibroin finishing liquid with a concentration of 40 g / L; then load the modified silk fibroin finishing liquid into a pneumatic spray gun, and uniformly spray the multifunctional finishing liquid on the surface of the silk product, so that the liquid carrying rate of the silk product is 40%, and the multifunctional silk product is obtained after air drying.

[0032] Embodiment 2

[0033] The multifunctional finishing liquid of the present embodiment and its application in silk products specifically include the following steps:

[0034] S1, tetrahydroxymethyl phosphonium chloride, polyhexamethylene biguanide, glutaraldehyde are added to a silk fibroin solution with a concentration of 20 g / L, then a diethyl phosphite solution is added dropwise, and the reaction is carried out at 70℃ for 90 min, and the modified silk fibroin is obtained after filtration and water washing; wherein the amount of tetrahydroxymethyl phosphonium chloride is 30 g / L, the amount of polyhexamethylene biguanide is 40 g / L, the amount of glutaraldehyde is 10 g / L, and the final amount of diethyl phosphite is 30 g / L;

[0035] S2, first disperse the modified silk fibroin in water, configure the modified silk fibroin finishing liquor with a concentration of 30g / L; then load the modified silk fibroin finishing liquor into the pneumatic spray gun, evenly spray the multifunctional finishing liquor on the surface of the silk product, so that the liquid carrying rate of the silk product is 30%, and the multifunctional silk product is obtained after air drying.

[0036] Example 3

[0037] The multifunctional finishing liquor of the embodiment and its application in silk products specifically include the following steps:

[0038] S1, add tetrahydroxymethyl phosphonium chloride, polyhexamethylene biguanide and glutaraldehyde to the silk fibroin solution with a concentration of 30g / L, then drop the diethyl phosphite solution, react at 80℃ for 60min, filter and wash to obtain the modified silk fibroin; wherein the amount of tetrahydroxymethyl phosphonium chloride is 50g / L, the amount of polyhexamethylene biguanide is 60g / L, the amount of glutaraldehyde is 15g / L, and the final amount of diethyl phosphite is 45g / L;

[0039] S2, first disperse the modified silk fibroin in water, configure the modified silk fibroin finishing liquor with a concentration of 50g / L; then load the modified silk fibroin finishing liquor into the pneumatic spray gun, evenly spray the multifunctional finishing liquor on the surface of the silk product, so that the liquid carrying rate of the silk product is 50%, and the multifunctional silk product is obtained after air drying.

[0040] Comparative Example 1

[0041] The same as Example 1, except that tetrahydroxymethyl phosphonium chloride is replaced by phosphoric acid.

[0042] Comparative Example 2

[0043] The same as Example 1, except that tetrahydroxymethyl phosphonium chloride is not added.

[0044] Comparative Example 3

[0045] The same as Example 1, except that polyhexamethylene biguanide is replaced by polyethyleneimine.

[0046] Comparative Example 4

[0047] The same as Example 1, except that polyhexamethylene biguanide is not added.

[0048] Comparative Example 5

[0049] The same as Example 1, except that glutaraldehyde is not added.

[0050] Comparative Example 6

[0051] The procedure of Example 1 was substantially the same, except that diethyl phosphite was replaced by diethyl phosphate.

[0052] Comparative Example 7

[0053] The procedure of Example 1 was substantially the same, except that diethyl phosphite was not added.

[0054] Test Example 1

[0055] The flame-retardant properties and other properties of the unfinishing silk product and the multifunctional silk product (finishing silk product) prepared in Examples 1-3 and Comparative Examples 1-8 were tested:

[0056] The antibacterial rate of the silk product was determined according to the standard of GB / T 20944.3-2008 “Evaluation of Antibacterial Properties of Textiles Part 3: Shake Flask Method”;

[0057] The mildew-proof property of the silk product was determined according to the standard of GB / T 24346-2009 “Evaluation of Mildew-Proof Property of Textiles”;

[0058] The flame-retardant property of the silk product was determined according to the standard of GB / T 5455-2014 “Determination of Vertical Burning Length, Afterglow and Afterflame Time of Textiles”;

[0059] Table 1 shows the finally measured properties of the unfinishing silk product and the finishing silk product:

[0060] Table 1

[0061] Specimen Inhibition rate of E. coli (%) Inhibition rate of S. aureus (%) Mildew-proof grade Char length (cm) Unfinished silk product 22.1 19.8 5 30 Example 1 97.6 98.5 0 11.3 Example 2 94.2 93.5 1 12.5 Example 3 99.9 99.9 0 10.8 Comparative Example 1 74.5 76.3 3 15.9 Comparative Example 2 73.9 75.6 3 23.1 Comparative Example 3 70.2 71.1 4 13.0 Comparative Example 4 65.5 68.9 4 15.3 Comparative Example 5 71.5 72.6 4 20.8 Comparative Example 6 91.2 92.3 2 16.4 Comparative Example 7 90.9 92.1 2 18.9

[0062] As can be seen from Table 1, the antibacterial rate of the multifunctional silk product of the examples on Escherichia coli and Staphylococcus aureus is 93.5%-99.9%, the mildew-proof grade is less than 1 level, and the char length is less than 12.5 cm, indicating that the multifunctional silk product has excellent antibacterial property, mildew-proof property and flame-retardant property.

[0063] As can be seen by comparing Example 1 and Comparative Example 1, when tetramethyl phosphonium chloride is replaced by phosphoric acid, the antibacterial property, mildew-proof property and flame-retardant property of the finishing silk product are reduced, because the antibacterial and mildew-proof property of phosphoric acid is poor, and phosphoric acid cannot covalently bond with polyhexamethylene biguanide and silk fibroin, resulting in that phosphoric acid cannot be grafted on silk fibroin, and lacking of acid source in the flame-retardant system, the flame-retardant efficiency is reduced.

[0064] As can be seen by comparing Example 1 and Comparative Example 2, when tetramethyl phosphonium chloride is not added, the antibacterial property, mildew-proof property and flame-retardant property of the finishing silk product are reduced, because tetramethyl phosphonium chloride has good antibacterial and mildew-proof effect, and is an acid source in the intumescent flame-retardant system.

[0065] As can be seen from the comparison between Comparative Example 1 and Comparative Example 3, when polyhexamethylene biguanide is replaced by polyethylene imine, the antibacterial property, mildew resistance and flame retardation of the finished silk product are reduced, because the antibacterial and mildew resistance of polyethylene imine is poor.

[0066] As can be seen from the comparison between Comparative Example 1 and Comparative Example 4, when polyhexamethylene biguanide is not added, the antibacterial property, mildew resistance and flame retardation of the finished silk product are reduced, because polyhexamethylene biguanide has good antibacterial and mildew resistance, and is the gas source in the intumescent flame retardant system.

[0067] As can be seen from the comparison between Comparative Example 1 and Comparative Example 5, when glutaraldehyde is not added, the antibacterial property, mildew resistance and flame retardation of the finished silk product are reduced, because glutaraldehyde can play a crosslinking role, and further grafts polyhexamethylene biguanide and diethyl phosphite on silk fibroin.

[0068] As can be seen from the comparison between Comparative Example 1 and Comparative Example 6, when diethyl phosphite is replaced by diethyl phosphate, the flame retardation of the finished silk product is significantly reduced, because diethyl phosphate cannot undergo Pudovik addition reaction with Schiff base C=N structure, and cannot be grafted on silk fibroin.

[0069] As can be seen from the comparison between Comparative Example 1 and Comparative Example 7, when diethyl phosphite is not added, the flame retardation of the finished silk product is significantly reduced, because diethyl phosphite can act as an acid source, thereby improving the flame retardation efficiency of the intumescent flame retardant system.

[0070] Obviously, the above examples are only examples for clearly illustrating, and are not limitation to the embodiments. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, all the embodiments need not and cannot be exhausted. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for preparing modified silk fibroin, characterized in that, Includes the following steps: Tetramethylphosphine chloride, polyhexamethylene biguanide, and glutaraldehyde were added to a silk fibroin solution, and then diethyl phosphite solution was added dropwise to react and obtain the modified silk fibroin. The mass ratio of tetramethylphosphine chloride, polyhexamethylene biguanide, glutaraldehyde, diethyl phosphite, and silk fibroin was (30-50):(40-60):(10-15):(30-45):(20-30).

2. The method for preparing modified silk fibroin according to claim 1, characterized in that, The concentration of the silk fibroin solution is 20g / L-30g / L.

3. The method for preparing modified silk fibroin according to claim 1, characterized in that, The reaction temperature is 70℃-80℃ and the time is 60min-90min.

4. The method for preparing modified silk fibroin according to claim 1, characterized in that, The solvent for the diethyl phosphite solution is ethanol; the mass ratio of diethyl phosphite to ethanol is 1:(1-2).

5. A modified silk fibroin prepared by the method of any one of claims 1-4.

6. A method for finishing multifunctional silk products, characterized in that, Includes the following steps: A modified silk fibroin finishing liquid is sprayed onto the surface of a silk product, and then dried to obtain the aforementioned multifunctional silk product. The modified silk fibroin finishing solution comprises the modified silk fibroin as described in claim 5 and water.

7. The method according to claim 6, characterized in that, The concentration of the modified silk fibroin finishing solution is 30g / L-50g / L.

8. The method according to claim 6, characterized in that, After spraying modified silk fibroin finishing liquid, the liquid retention rate of silk products is 30%-50%.

9. A multifunctional silk product obtained by the method described in any one of claims 6-8.