阅读说明：本技术 一种简便高效的老化蚕丝丝素蛋白纤维修复方法 (Simple and efficient aged silk fibroin fiber repairing method ) 是由 林乃波 李小宝 于 2021-10-26 设计创作，主要内容包括：一种简便高效的老化蚕丝丝素蛋白纤维修复方法,涉及织物整理。将老化的蚕丝丝素蛋白纤维置于1-(3-二甲基氨基丙基)-3-乙基碳化二亚胺(EDC)和N-羟基丁二酰亚胺(NHS)混合溶液和活性分子中进行交联,通过交联触发剂实现对老化蚕丝的化学和物理交联,修复被破坏蚕丝丝素蛋白纤维的分子链,得到老化修复的蚕丝蛋白纤维,实现力学性能修复。修复的老化蚕丝丝素蛋白纤维的单根纤维的断裂强度可达老化蚕丝丝素蛋白纤维的3倍左右,断裂应变可达老化蚕丝丝素蛋白纤维的6倍左右。不仅增加了化学交联机率,而且提供了氢键等非共价键的物理交联点。修复过程简单成本低,效率高,为丝绸修复提供重要的技术参考。(A simple, convenient and efficient method for repairing aged silk fibroin fibers, which relates to fabric finishing. Placing the aged silk fibroin fibers in a mixed solution of 1- (3-dimethylaminopropyl) -3-Ethylcarbodiimide (EDC) and N-hydroxysuccinimide (NHS) and active molecules for crosslinking, realizing chemical and physical crosslinking of the aged silk by a crosslinking trigger, repairing molecular chains of the damaged silk fibroin fibers, obtaining the aged and repaired silk fibroin fibers, and realizing mechanical property repair. The breaking strength of single fibers of the repaired aged silk fibroin fibers can reach about 3 times of that of the aged silk fibroin fibers, and the breaking strain can reach about 6 times of that of the aged silk fibroin fibers. Not only increases the chemical crosslinking probability, but also provides non-covalent bond physical crosslinking points such as hydrogen bonds. The repair process is simple, low in cost and high in efficiency, and provides important technical reference for silk repair.)

1. A simple, convenient and efficient method for repairing aged silk fibroin fibers is characterized by comprising the following specific steps: placing the aged silk fibroin fibers in a crosslinking trigger for reaction, realizing chemical and physical crosslinking of the aged silk through the crosslinking trigger, repairing molecular chains of the damaged silk fibroin fibers, washing to remove surface impurities, and drying to obtain the repaired silk fibroin fibers.

2. The simple and efficient method for repairing aged silk fibroin fiber according to claim 1, wherein the silk fibroin fiber is selected from one of bombyx mori silk and tussah silk.

3. The simple and efficient repair method for aged silk fibroin fibers according to claim 1, wherein the aging comprises natural aging, thermal aging, and chemical corrosion aging.

4. The method for repairing aged silk fibroin fibers as claimed in claim 1, wherein the cross-linking trigger is prepared by mixing 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide, N-hydroxysuccinimide, and a reagent containing multiple carboxyl groups/amino groups in a certain ratio.

5. The simple and efficient repair method for aged silk fibroin fibers according to claim 4, wherein the cross-linking trigger is prepared by adding 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide and N-hydroxysuccinimide into deionized water to prepare a coupling agent catalyst solution, adding a reagent containing polycarboxyl/amino, and mixing.

6. The simple and efficient method for repairing aged silk fibroin fibers according to claim 4 or 5, wherein the agent containing polycarboxyl/amino groups is selected from the group consisting of sodium alginate, polyglutamic acid, silk fibroin, sodium caseinate, polylysine, ethylenediamine, melamine, urea, polyethylene glycol glycidyl ether, and glycerol.

7. The simple and efficient repair method for aged silk fibroin fibers according to claim 5, wherein the ratio of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide, N-hydroxysuccinimide and deionized water is 2: 1: 50-500, and the concentration of the polycarboxyl/amino group-containing reagent is within the saturated concentration of the reagent.

8. The simple and efficient repair method for aged silk fibroin fibers according to claim 1, wherein the reaction temperature is 1-25 ℃ and the reaction time is 2-72 h.

Technical Field

The invention relates to the field of fabric finishing, in particular to a simple, convenient and efficient method for repairing aged silk fibroin fibers.

Background

The delicate and luxurious silk is a treasure with a long history in China. It is the witness of civilization of human beings and one of the symbols of ancient culture of China. The raw silk is a product obtained by reeling silkworm cocoons, is a protein fiber, consists of silk fibroin (about 75 percent) and sericin (about 25 percent), contains 18 amino acids, and various amino acid side groups endow the silk protein with the capabilities of reaction and modification. Degumming the raw silk to prepare the silk fibroin fiber fabric. Due to the characteristics of silk fibroin and the special secondary structure, the silk fibroin is extremely vulnerable to heat, light, water and microorganisms. The burial unearthed silk fabric is carbonized and degraded due to the influence of different geographical environments, and the preservation and the repair of the burial unearthed silk fabric become a difficult task.

To determine the appropriate treatment for storage and display of ancient textiles, various methods have been developed to protect and reinforce ancient silk fabrics. Originally Eric f.hansen and William s.ginell (Hansen, e.f.; Ginell, w.s., The convergence of Silk with Parylene-c.in historian textiles and Paper Materials II [ J ], 1989; pp 108-. The method for reinforcing silk also comprises adhesive, film, raw material supply and enzymatic and hydrophobic coating. For example, chinese patent CN 101619540a is used to reinforce silk by an adhesive method. Firstly, silk fibroin is dissolved, the obtained silk fibroin solution is soaked in aged silk, and then the silk is treated by an Acramin F-type adhesive. The Chinese patent CN 101613936B also utilizes silk fibroin solution and self-crosslinking adhesive KG-101B solution to reinforce silk fabric. The method can effectively increase the strength of the silk cultural relics, reduce the influence of reinforcement on the cultural relics and is beneficial to the protection of the silk cultural relics to a certain extent. In addition, Chinese patent CN 101613937A uses ethylene glycol diglycidyl ether solution to replace self-crosslinking adhesive KG-101B solution as a reinforcing agent to be used as ancient silk. Although these methods can play a certain role in silk preservation, a simple protective layer is formed only by crosslinking on the surface of silk fabric, and the preparation of silk fibroin solution is cumbersome and difficult to preserve and transport.

The search for a simple and effective method is urgent, and the chinese patent CN 102359015B replaces the silk fibroin solution with an amino acid solution. The reinforcing agent is composed of mixed solution of L-lysine, L-cysteine, L-arginine and ethylene glycol diglycidyl ether solution. The amino acid mixed solution and the ethylene glycol diglycidyl ether solution are uniformly sprayed on the surface of the silk cultural relics in sequence. The method solves the defects of complicated preparation and difficult transportation and storage of silk fibroin solution, but the method does not prove that the reinforcing agent permeates into silk fiber to connect molecular chains inside the silk due to the technical problem, and just forms a protective layer on the surface of the silk as in Chinese patents CN 101619540A and CN 101613936B. The method can well reduce the interference of the reagent on the silk fibroin fibers, but does not well repair the silk fibers, and the silk fibers are still fragile. The Chinese patent CN 111849340A uses acrylic polyurethane aqueous dispersion, thixotropic agent, deionized water, defoaming agent, plant mothproofing agent and purified water mixed solution as a reinforcing agent, provides a processing protective solution and a processing method for unearthed silk paper cultural relics, and can quickly process and protect the unearthed silk and paper cultural relics, so that the unearthed silk and paper cultural relics can not be oxidized and deformed in the air and illumination environment, the time is won for subsequent restoration, and great convenience is brought to the unearthed protection of the silk and paper cultural and painting. This method also has some limitations, changing silk into a plate-like substance similar to paper, only plays a protective role, and is not repaired.

The silk fibroin fiber repairing process is further optimized to improve the repairing effect by aiming at the internal repairing of silk fibroin fiber molecules, and the repairing effect is improved by using bacterial cellulose to repair silk, wherein the repairing effect is better expected by using Shun-Qing Wu, Mei-Ying Li and the like (Wu, S. -Q.; Li, M. -Y.; Fan, B. -S.; Tong, H., (requirement of flexible silk fibroin slurry fibers with bacterial cellulose and tissue light bonding fibers J. Carbohydrate Polymers 2012,88(2),496 and 501.) the silk fibroin fiber molecules are modified by using the bacterial cellulose. The method relates to the cultivation of bacteria, and has very harsh required conditions and complicated operation. To solve such cumbersome operations and achieve the same or even better results, Suhua ZHao, Hongliang Pan et al (ZHao, S.; Pan, H.; Liu, Y.; Zeng, Y.; Liu, H.; Yu, W.; Silk Textile protection associated with vitamin chemical coupling [ J ]. Textille Research Journal 2019,89(21-22), 4581-. After 10 times of circular washing, the mechanical property of the reinforced real silk fabric is not obviously changed, and the washing durability is better. After TGase and SC are enhanced, silk fibroin solution is sprayed on the surface of real silk fabric to improve the mechanical property of the real silk fabric, and the mechanical property of the real silk fabric can be improved by further assembling the silk fibroin. After treatment, the breaking strength of the silk material can be improved from 45MPa to about 56MPa, the breaking strength is increased by about 1.3 times, and the breaking stress is also increased by about 1.5 times. The method utilizes chemical reaction formed between different silk fibroin fibers, improves the mechanical strength, and does not realize the repair of molecular chains in the silk fibroin fibers.

In chemical modification of proteins, three reactive groups on the protein are often utilized: thiols (-SH), amines (-NH)₂) And a carboxyl group (-COOH). 1- (3-dimethylaminopropyl) -3-ethylcarbodiimideimine/N-hydroxysuccinimide (EDC/NHS) is a "zero length" cross-linking agent and does not produce any toxic by-products in the matrix. The EDC/NHS activation method has many advantages: the conversion efficiency is high, the reaction condition is mild, the biocompatibility is good, the influence on the biological activity of target molecules is small, and the product is cleaner than other cross-linking agents such as glutaraldehyde, formaldehyde and the like. Because of these advantages, EDC/NHS activation and amidation reactions of carboxylic acids have been widely used in biomolecule coupling and nanotube immobilization of proteins, peptides, DNA and the like to various substrates such as polymers, noble metals, silicon, nanoparticles and the like, Qingqing Li, Yang Zhang et al (Qingqing Li, Yang Zhang, Zhen Wu, Jingnan Huang, Ningning Yue, Lin Huang, and Xumin Zhang. Tyrosine-EDC Conjugation, an Underable Side Effect of the EDC catalyzed Carboxyl laboratory apparatus [ J]Analytical chemistry 2021,93(2),697-703) systematically analysed that EDC/NHS produced external reactions during protein coupling, which involved substantially all of the amino acids within silk fibroin. Therefore, the method is very suitable for repairing silk.

The invention adopts a physical and EDC/NHS chemical crosslinking method to repair silk fibroin fibers and realize good repair of aged silk fibroin fibers.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a simple, convenient and efficient method for repairing aged silk fibroin fibers for further improving the repairing effect of silk fibroin fibers with a damaged structure.

The simple and efficient aged silk fibroin fiber repairing method comprises the following specific steps: placing the aged silk fibroin fibers in a crosslinking trigger for reaction, realizing chemical and physical crosslinking of the aged silk through the crosslinking trigger, and repairing molecular chains of the damaged silk fibroin fibers to obtain the aged and repaired silk fibroin fibers; washing to remove impurities on the surface, and drying to obtain the repaired fibroin fiber.

The silk fibroin fiber is selected from one of silkworm silk and tussah silk.

The aging includes natural aging, thermal aging, and chemical corrosion aging.

The crosslinking trigger is formed by mixing 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide, N-hydroxysuccinimide and a reagent containing polycarboxyl/amino according to a proportion; adding 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide and N-hydroxysuccinimide into deionized water to prepare a coupling agent catalyst solution, adding a reagent containing polycarboxyl/amino, and mixing to obtain a crosslinking trigger; the reagent can be selected from sodium alginate, polyglutamic acid, silk fibroin, sodium caseinate, polylysine, ethylenediamine, melamine, urea, polyethylene diamine, polyethylene glycol glycidyl ether, glycerol and other materials containing polycarboxyl/amino.

The ratio of the 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide, the N-hydroxysuccinimide and the deionized water can be 2: 1: 50-500, and the concentration of the polycarboxyl/amino-containing reagent is within the saturated concentration of the reagent.

The reaction temperature can be 1-25 ℃, and the reaction time is within the time for starting dissolving the silk fibroin fiber surface, generally 2-72 h.

The breaking strength of single fibers of the repaired aged silk fibroin fibers can reach about 3 times of that of the aged silk fibroin fibers, and the breaking strain can reach about 6 times of that of the aged silk fibroin fibers. The repaired silk fibroin fiber surface has no redundant impurities, and the fracture tensile section is more and more smooth, which proves that the coupling agent repairs the internal defects of the silk fibroin fiber.

According to the invention, carboxyl and amino crosslinking in silk fibroin can be triggered, EDC, NHS and a crosslinking trigger liquid system rich in amino (carboxyl) reagents are added into the carboxyl (amino) of the silk fibroin and the outside, the amino and the carboxyl form an amido bond under the driving of the system, and the broken molecular chain is connected to repair the defects in the silk fibroin, so that the repaired aged silk fibroin fiber with greatly increased mechanical strength and smoother fracture opening is obtained. In addition, the polar group in the agent rich in amino (carboxyl) can generate strong interaction physical interaction with the polar group in the aging fibroin molecular chain, such as hydrogen bond interaction and the like, and is beneficial to further repair of the aging fibroin fiber. Compared with the prior art, the aged silk fiber repaired by the method has the advantages of larger and more uniform strength increase times, simple repairing process, low cost and high efficiency, and provides important technical reference for silk repair.

Drawings

FIG. 1 is a tensile test chart of silk fibroin fibers of Bombyx mori silk aged at 180 ℃ in example 2.

FIG. 2 is a graph showing tensile test results of sodium caseinate, 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide and N-hydroxysuccinimide treated silk fibroin fibers of Bombyx mori L.in example 2.

FIG. 3 is a scanning electron microscope image of the tensile fracture surface of silk fibroin fibers of Bombyx mori silk aged at 180 ℃ in example 2.

FIG. 4 is a scanning electron microscope image of the tensile fracture surface of silk fibroin fibers of Bombyx mori treated with sodium caseinate, 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide and N-hydroxysuccinimide repair solutions of example 2.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the following embodiments will be further described with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Furthermore, in the following detailed description of the present invention, certain specific details are set forth in order to provide a better understanding of the present invention. It will be apparent to one skilled in the art that the present invention may be practiced without these specific details.

The method for repairing the aged silk fibroin fibers provided by the embodiment of the invention comprises the following steps:

1) taking silk fibroin fibers aged by natural aging, heat aging and chemical corrosion;

2) dissolving the chemical reactant in deionized water: the ratio of the concentration of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide to the concentration of N-hydroxysuccinimide is 2: 1, and the concentration of sodium caseinate is within the saturated concentration of the reagent, so as to obtain a crosslinking trigger;

3) placing the aged silk fibroin fibers obtained in the step 1) into the crosslinking trigger in the step 2), and reacting for a proper time (2-72 h) at a certain environmental temperature (1-25 ℃) to obtain aged and repaired silk fibroin fibers;

4) washing the chemically repaired silk fibroin fibers obtained in the step 3) with a proper amount of deionized water, removing impurities on the surface, and drying at room temperature to obtain the finally repaired silk fibroin fibers.

Specific examples are given below.

Example 1

a. Sample preparation

And (3) taking the naturally aged bombyx mori silk fibroin fibers from the museum for later use.

b. Preparation of EDC, NHS Mixed solution

EDC and NHS are added into deionized water to form mixed solution (11 parts) with the mass ratio of 2: 1: 80, and the mixed solution is used as coupling agent catalyst solution.

c. Preparation of the repair solution

Adding 0.5g of reagents (respectively sodium alginate, polyglutamic acid, silk fibroin, sodium caseinate, polylysine, ethylenediamine, melamine, urea, polyethylene diamine, polyethylene glycol glycidyl ether, glycerol and the like) rich in amino or carboxyl into the catalytic solution prepared in the step b), mixing into 11 parts of repairing solution, and placing in an environment at 4 ℃.

d. Repair of natural aged silkworm silk fibroin fibers

And (c) adding the naturally aged silkworm silk fibroin fibers in the step a into the 11 mixed solutions prepared in the step c respectively, and reacting for 24 hours in an environment at 4 ℃.

e. Repaired silkworm silk fibroin fiber

And d, taking out the silk fibroin fibers of the silkworms processed in the step d, washing impurities on the surface with deionized water, and drying at room temperature to obtain the repaired silk fibroin fibers of the silkworms.

The results are shown in Table 1.

Example 2

a. Sample preparation (reeling, degumming and heat aging)

Boiling silkworm cocoon in 95 deg.C water for 5min, and drawing silk fiber at a certain rotation speed; drawing 5g Na of silk fiber at 95 DEG C₂CO₃Degumming the mixture of 10g of soap and 1000ml of deionized water for 45min twice, washing the mixture with deionized water after each degumming, and drying the mixture at room temperature; the dried silk fibroin fiber is placed in an environment of 180 ℃ for heat treatment for 24 hours to obtain aged silk fibroin fiber of silkworms with damaged structures; the tensile test chart of the silk fibroin fiber aged at 180 ℃ is shown in figure 1.

b. Preparation of EDC, NHS Mixed solution

EDC and NHS are added into deionized water to form mixed solution (11 parts) with the mass ratio of 2: 1: 100 as coupling agent catalyst solution.

c. Preparation of the repair solution

Adding 0.5g of reagents (respectively sodium alginate, polyglutamic acid, silk fibroin, sodium caseinate, polylysine, ethylenediamine, melamine, urea, polyethylene diamine, polyethylene glycol glycidyl ether, glycerol and the like) rich in amino or carboxyl into the catalytic solution prepared in the step b), mixing into 11 parts of repairing solution, and placing in an environment at 4 ℃.

d. Restoration of aged silkworm silk fibroin fibers

And (c) adding the aged silkworm silk fibroin fibers with the damaged structures in the step a into the 11 mixed solutions prepared in the step c respectively, and reacting for 20-30 h in an environment at 1-15 ℃.

e. Repaired silkworm silk fibroin fiber

And d, taking out the silk fibroin fibers of the silkworms treated in the step d, washing impurities on the surface with deionized water, and drying at room temperature to obtain the repaired silk fibroin fibers of the silkworms.

The results are shown in Table 2. FIG. 2 is a graph showing tensile test results of sodium caseinate, 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide and N-hydroxysuccinimide treated silk fibroin fibers of Bombyx mori L.in example 2. FIG. 3 is a scanning electron microscope image of the tensile fracture surface of silk fibroin fibers of Bombyx mori silk aged at 180 ℃ in example 2. FIG. 4 is a scanning electron microscope image of the tensile fracture surface of silk fibroin fibers of Bombyx mori treated with sodium caseinate, 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide and N-hydroxysuccinimide repair solutions of example 2.

Example 3

a. Sample preparation (reeling, degumming and hexafluoroisopropanol aging)

Boiling silkworm cocoon in 95 deg.C water for 5min, and drawing silk fiber at a certain rotation speed; drawing 5g Na of silk fiber at 95 DEG C₂CO₃Degumming the mixture of 10g of soap and 1000ml of deionized water for 45min twice, washing the mixture with deionized water after each degumming, and drying the mixture at room temperature; and (3) treating the dried silk fibroin fibers for 24h by placing a proper amount of hexafluoroisopropanol reagent at 60 ℃ to obtain the aged silk fibroin fibers with the damaged structure.

b. Preparation of EDC, NHS Mixed solution

EDC and NHS are added into deionized water to form mixed solution (11 parts) with the mass ratio of 2: 1: 100 as coupling agent catalyst solution.

c. Preparation of the repair solution

Adding 0.5g of reagents (respectively sodium alginate, polyglutamic acid, silk fibroin, sodium caseinate, polylysine, ethylenediamine, melamine, urea, polyethylene diamine, polyethylene glycol glycidyl ether, glycerol and the like) rich in amino or carboxyl into the catalytic solution prepared in the step b), mixing into 11 parts of repairing solution, and placing in an environment at 4 ℃.

d. Restoration of aged silkworm silk fibroin fibers treated by hexafluoroisopropanol

And (c) adding the aged silkworm silk fibroin fibers with the damaged structures in the step a into the 11 mixed solutions prepared in the step c respectively, and reacting for 24-28 h in an environment at 4 ℃.

e. Repaired silkworm silk fibroin fiber

And d, taking out the silkworm silk fibroin fibers treated for 24-28 h in the step d, washing impurities on the surface with deionized water, and drying at room temperature to obtain the repaired silkworm silk fibroin fibers.

The results are shown in Table 3.

Example 4

a. Sample preparation

And taking the natural aged tussah silk fibroin fiber from a museum for later use.

b. Preparation of EDC and NHS mixed solution

EDC and NHS are added into deionized water to form mixed solution (11 parts) with the mass ratio of 2: 1: 200, and the mixed solution is used as coupling agent catalyst solution.

c. Preparation of the repair solution

Adding 0.5g of reagents (respectively sodium alginate, polyglutamic acid, silk fibroin, sodium caseinate, polylysine, ethylenediamine, melamine, urea, polyethylene diamine, polyethylene glycol glycidyl ether, glycerol and the like) rich in amino or carboxyl into the catalytic solution prepared in the step b), mixing into 11 parts of repairing solution, and placing in an environment at 4 ℃.

d. Repair of natural aged tussah silk fibroin fiber

And (c) adding the natural aged tussah silk fibroin fibers in the step a into the 11 mixed solutions prepared in the step c respectively, and reacting for 20-40 h in an environment at 1-10 ℃.

e. Repaired tussah silk fibroin fiber

And d, taking out the tussah silk fibroin fibers treated in the step d, washing impurities on the surface with deionized water, and drying at room temperature to obtain the repaired tussah silk fibroin fibers.

The results are shown in Table 4.

Example 5

a. Sample preparation (reeling, degumming and heat aging)

Silkworm of tussahBoiling cocoon in 95 deg.C water for 5min, and drawing silk fiber at a certain rotation speed; drawing 5g Na of silk fiber at 95 DEG C₂CO₃Degumming the mixture of 10g of soap and 1000mL of deionized water for 45min twice, washing the mixture with deionized water after each degumming, and drying the mixture at room temperature; and (3) placing the dried silk fibroin fiber in an environment of 180 ℃ for heat aging for 24h to obtain the aged tussah silk fibroin fiber with a damaged structure.

b. Preparation of EDC, NHS Mixed solution

EDC and NHS are added into deionized water to form mixed solution (11 parts) with the mass ratio of 2: 1: 500 as coupling agent catalyst solution.

c. Preparation of the repair solution

Adding 0.5g of reagents (respectively sodium alginate, polyglutamic acid, silk fibroin, sodium caseinate, polylysine, ethylenediamine, melamine, urea, polyethylene diamine, polyethylene glycol glycidyl ether, glycerol and the like) rich in amino or carboxyl into the catalytic solution prepared in the step b), mixing into 11 parts of repairing solution, and placing in an environment at 4 ℃.

d. Restoration of aged tussah silk fibroin fibers

And (c) adding the aged tussah silk fibroin fibers with the damaged structures in the step a into the 11 mixed solutions prepared in the step c respectively, and reacting for 24-72 hours in an environment at 4-25 ℃.

e. Repaired tussah silk fibroin fiber

And d, taking out the tussah silk fibroin fibers treated in the step d, washing impurities on the surface with deionized water, and drying at room temperature to obtain the repaired tussah silk fibroin fibers.

The results are shown in Table 5.

Example 6

a. Sample preparation (reeling, degumming and hexafluoroisopropanol aging)

Boiling tussah cocoon in 95 deg.C water for 5min, and drawing silk fiber at a certain rotation speed; drawing 5g Na of silk fiber at 95 DEG C₂CO₃A mixture of 10g soap and 1000ml deionized waterDegumming for 45min twice in the solution, washing with deionized water after each degumming, and drying at room temperature; and (3) treating the dried silk fibroin fibers by a proper amount of hexafluoroisopropanol reagent at 60 ℃ for 24 hours to obtain the aged tussah silk fibroin fibers with damaged structures.

b. Preparation of EDC, NHS Mixed solution

EDC and NHS are added into deionized water to form mixed solution (11 parts) with the mass ratio of 2: 1: 100 as coupling agent catalyst solution.

c. Preparation of the repair solution

Adding 0.5g of reagents (respectively sodium alginate, polyglutamic acid, silk fibroin, sodium caseinate, polylysine, ethylenediamine, melamine, urea, polyethylene diamine, polyethylene glycol glycidyl ether, glycerol and the like) rich in amino or carboxyl into the catalytic solution prepared in the step b), mixing into 11 parts of repairing solution, and placing in an environment at 4 ℃.

d. Restoration of aged tussah silk fibroin fibers treated by hexafluoroisopropanol

And (c) adding the aged tussah silk fibroin fibers with the damaged structures in the step a into the 11 mixed solutions prepared in the step c respectively, and reacting for 24 hours in an environment at 4 ℃.

e. Repaired tussah silk fibroin fiber

And d, taking out the tussah silk fibroin fibers treated for 24 hours in the step d, washing impurities on the surface with deionized water, and drying at room temperature to obtain the repaired tussah silk fibroin fibers.

The results are shown in Table 6.

TABLE 1

TABLE 2

TABLE 3

TABLE 4

TABLE 5

TABLE 6

As can be seen from FIG. 1, the mechanical strength of silk fibroin fibers of Bombyx mori which is aged at 180 ℃ is very low.

As can be seen from FIG. 2, the mechanical strength of the silk fibroin fibers repaired by the mixed aqueous solution of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide, N-hydroxysuccinimide and sodium caseinate is greatly increased.

From fig. 3 and 4, it can be seen that the fracture surface of silk fibroin fiber with weak mechanical properties is uneven, and the fracture surface of repaired silk fibroin fiber with greatly increased mechanical properties is relatively flat, which indicates that the sodium caseinate aqueous solution repair solution of NHS and EDC has a repair effect on the internal defects of silk fibroin fiber.