Machine washable silk fabric and preparation method thereof

Abstract

The present application provides a preparation method of a machine-washable silk fabric, the preparation method cleans silk cocoons, boils and degummes, washes, dries, obtains silk fiber, then the silk fiber is dissolved in a neutral salt solution, through dialysis, obtains a fibroin solution;Then, prepare a dopamine solution, and mix it with the aforementioned fibroin solution to obtain a mixed solution;Finally, the process of padding, baking, washing, and then baking is performed by rolling and baking the aforementioned mixed solution to the silk fabric, and through 2 5 rolling and baking processes, a machine-washable silk fabric is obtained. The present application adopts a polydopamine protein coating with good biocompatibility, utilizes hydrogen bonds between polydopamine, fibroin and silk fabric and electrostatic multiple forces, while not changing the softness and comfort of silk fabric itself, improves the mechanical strength, friction resistance and water washing / machine washing resistance of silk fabric, and extends its nursing convenience and service life.

Description

Technical Field

[0001] The present application relates to the technical field of silk fiber surface modification, and in particular to a machine-washable silk fabric and a preparation method thereof. Background Art

[0002] Silk fiber has good biocompatibility. Silk fabrics made from silk fibers have a smooth, soft, skin-friendly feel, good air permeability and moisture permeability, and good drape. They are representative high-end fabrics in the field of textiles and clothing. However, silk fibers are relatively fragile when wet, and their mechanical properties and resistance to chemicals (such as detergents) are poor, making them susceptible to damage and deformation. In modern life, with people's pursuit of high-quality and efficient life, eliminating housework has become a popular trend. Household textiles are mostly cleaned by machine washing, but silk fabrics are easily worn during machine washing, causing problems such as fibrillation, wrinkling and shrinkage, which affect subsequent use. Therefore, if you want to completely free your hands, you also need to improve the machine washability of silk fabrics.

[0003] In the existing technology, some researchers have tried to improve the silk fabric by coating it with polyurethane or polyester coating. However, this method not only makes the silk fiber lose its natural soft texture and skin-friendliness, but also seriously increases the environmental burden of textiles because such coating materials are difficult to recycle and biodegrade. Some researchers have used resin to finish silk fabrics, which has improved the wrinkle resistance and dust damage resistance of silk fabrics, but its hydrophilicity has significantly deteriorated and the feel has become significantly harder. Some researchers have used acrylamide and chitosan citric acid to finish silk fabrics, which has improved the wrinkle resistance of silk fabrics, but this finishing method requires high-temperature baking, which is not only prone to fiber loss, but also affects the color of the fabric.

[0004] In summary, while most current finishing methods can impart excellent functional properties to silk fibers, relatively little research has been conducted on the machine washability of silk fabrics. While a few reports indicate that some methods can improve the machine washability of silk fabrics, these often compromise properties such as hand feel, gloss, color, and moisture absorption. Therefore, it is necessary to design a machine-washable silk fabric and its preparation method to address these issues. Summary of the Invention

[0005] The present application provides a machine-washable silk fabric and a preparation method thereof, aiming to solve the problem in the background art that the existing machine-washable finishing method is not environmentally friendly and causes the silk fabric to lose its hand feel, gloss, moisture absorption and other wearing properties. The preparation method proposed in this application uses silk fibroin and polydopamine as coating materials, which are finished on the surface of the silk fabric by padding and low-temperature baking to obtain a machine-washable silk fabric. The finished silk fabric retains the original softness and skin-friendliness of the silk fiber, and its mechanical strength and wear resistance are greatly improved, extending its service life. After 30 machine washes, there is no obvious damage or burrs on the coating surface.

[0006] In a first aspect, an embodiment of the present application provides a method for preparing a machine-washable silk fabric, comprising the following steps:

[0007] S1, boiling and degumming the pretreated silk cocoons, washing with deionized water, and drying to obtain silk fibers, dissolving the silk fibers in a neutral salt solution, and then dialyzing to remove salt to obtain a silk fibroin solution;

[0008] S2, dissolving dopamine hydrochloride in Tris-HCl buffer to prepare a dopamine solution, mixing the dopamine solution with the silk fibroin solution prepared in step S1, and gently stirring until the mixture is uniform to obtain a mixed solution;

[0009] S3, using the mixed solution obtained in step S2 to finish the silk fabric to obtain a machine-washable silk fabric; wherein the finishing includes 2-5 padding and baking treatments, wherein the padding and baking treatments are to pad the silk fabric, dry it at 35-45°C, wash it with water, and then bake it at 35-45°C for 5-10 minutes.

[0010] In step S2 of some embodiments, the concentration of the Tris-HCl buffer is 5-15 mmol / L, the pH of the Tris-HCl buffer is 7.5-8.5, and the concentration of the dopamine solution is 1.8-2.2 mg / mL.

[0011] In step S2 of some embodiments, in the mixed solution, the mass ratio of silk fibroin to dopamine is (8-12):1, and the pH of the mixed solution is 7-8.5.

[0012] In step S1 of some embodiments, the boiling degumming is to place the pretreated cocoons in deionized water and heat them for 30-50 minutes, then maintain the temperature at 70-85°C, add an alkali agent in four times and stir thoroughly, each time with an interval of 10 minutes; wherein the total duration of the boiling degumming is 1.5-2 hours, the alkali agent is NaHCO3 and Na2CO3, and the mass ratio of the pretreated cocoons to NaHCO3 and Na2CO3 is (18-22):2:1.

[0013] In step S1 of some embodiments, the neutral salt solution is a lithium bromide aqueous solution, and the concentration of the lithium bromide aqueous solution is 10-12 mol / L.

[0014] In step S1 of some embodiments, the pretreatment is to cut the cocoons, remove the silkworm pupae and the dirty silk parts inside the cocoons, cut the remaining parts into small pieces, wash them with deionized water, and dry them.

[0015] In step S1 of some embodiments, the dissolution temperature of the silk fiber is 60-70° C., and the dissolution time is 6-8 hours.

[0016] In step S1 of some embodiments, the dialysis time is 3-5 days.

[0017] In step S3 of some embodiments, the pressure of the roller is 2-3 kg / cm 2 .

[0018] In a second aspect, an embodiment of the present application provides a machine-washable silk fabric, which is prepared according to the preparation method described in any of the aforementioned technical solutions.

[0019] The beneficial effects of this application are:

[0020] The present application provides a machine-washable silk fabric and a preparation method thereof, which solves the problem in the background art that the existing machine-washable finishing method is not environmentally friendly and will cause the loss of the silk fabric's feel, gloss, moisture absorption and other wearing properties. The preparation method proposed in the present application uses silk fibroin and polydopamine as coating materials, and finishes them on the surface of the silk fabric through a padding treatment and low-temperature baking to obtain a machine-washable silk fabric. The finished silk fabric retains the original softness and skin-friendliness of the silk fiber, and the mechanical strength and wear resistance are greatly improved, extending the service life. After 30 machine washes, there is no obvious damage or burrs on the coating surface, which can meet the needs of the high-end market and multi-functional applications, and enhance the market competitiveness of the product.

[0021] (1) The present application uses silk fibroin and polydopamine with good biocompatibility as coating materials, which retains the original softness and skin-friendliness of silk fibers, and does not use any polluting and toxic reagents or drugs in the preparation process, which is in line with the concept of green environmental protection; in addition, the present application adopts low-temperature baking in the rolling and baking treatment, and increases the fixing strength and fixing amount of the coating through multiple rolling and baking treatments, thereby protecting the silk fibers from damage during the treatment process.

[0022] (2) The silk fibroin used in this application has the same biological origin as the silk fiber. On the one hand, it will not cause skin irritation or allergic reaction, but can also retain the original softness, skin-friendliness, and natural luster of the silk fiber. On the other hand, since the components of the two are almost the same, they have good affinity with each other, which can greatly improve the interface fastness.

[0023] (3) The polydopamine and fibroin used in this application are fused with each other to form a polydopamine protein coating, which greatly improves the water-washing resistance of silk fibers. This is because, in the alkaline mixed solution of fibroin and dopamine, dopamine continuously undergoes oxidative self-polymerization to form polydopamine, and the structure of polydopamine is similar to that of mussel adhesive protein, and has self-adhesive properties, which enables it to firmly adhere to the surface of silk. At the same time, the multiple hydroxyl groups and amine groups in the molecular structure of polydopamine form hydrogen bonds and other non-covalent bonds with the hydroxyl groups and amine groups on the surface of fibroin, which enhances the interaction between polydopamine and fibroin, and hydrogen bonds and other non-covalent bonds are formed between polydopamine and silk fabric in the same way. In this way, hydrogen bonds and electrostatic forces exist between polydopamine, fibroin and silk fabric, which work together to greatly enhance the interfacial bonding force between the polydopamine protein coating and the silk fabric, thereby improving the mechanical strength and wear resistance of the silk fabric and extending its service life.

[0024] (4) The washable finishing process provided by the present application can be combined with other functional finishing processes, and different functional properties can be given to machine-washable silk fabrics without the need for additional steps, thereby meeting consumers' demand for high-performance, multifunctional textiles. For example, by adding certain functional additives or essential oil aromatic finishing agents to the mixed solution used for padding, such as titanium dioxide nanoparticles, zinc oxide nanoparticles, rose essential oil, and peppermint essential oil, the machine-washable silk fabrics can be given the effects of anti-ultraviolet, soothing mood, and refreshing. In addition, the polydopamine in the coating is a catechol derivative with good biocompatibility and low toxicity, which can inhibit the attachment and growth of bacteria, so that the polydopamine protein coating also has potential antibacterial properties.

[0025] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the technical solution of this application, the following is a brief introduction to the drawings used in this application. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0027] Figure 1 These are electron micrographs of the fibers of the machine-washable silk fabric and the ordinary silk fabric prepared in Example 1 after being machine washed 30 times, respectively. Among them, (a), (b), (c), and (d) are electron micrographs of the fibers of the ordinary silk fabric after being washed 30 times, and (e), (f), (g), and (h) are electron micrographs of the fibers of the machine-washable silk fabric prepared in Example 1 after being washed 30 times.

[0028] Figure 2 3 are apparent color comparison diagrams of ordinary silk fabric and machine washable silk fabric, wherein (i) is the apparent color diagram of ordinary silk fabric, (j) is a partial enlarged diagram of (i), (k) is the apparent color diagram of the machine washable silk fabric prepared in Example 1, and (l) is a partial enlarged diagram of (k). DETAILED DESCRIPTION

[0029] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0031] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0032] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0033] In the description of the embodiments of this application, the term "and / or" is merely a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0034] In order to solve the problem that the existing machine washable finishing method is not environmentally friendly and will cause the loss of the feel, gloss, moisture absorption and moisturizing performance of silk fabrics, the present application provides a machine washable silk fabric and a preparation method thereof. The preparation method uses silk fibroin and polydopamine as coating materials, and finishes them on the surface of the silk fabric by padding and low-temperature baking. The covalent bonds, hydrogen bonds and electrostatic forces between polydopamine, silk fibroin and silk fabric are used to improve the interface bonding strength between the coating material and the base material, so that the silk fabric has machine washability.

[0035] The present invention provides a method for preparing a machine-washable silk fabric, comprising the following steps:

[0036] S1, boiling and degumming the pretreated silk cocoons, washing with deionized water, and drying to obtain silk fibers, dissolving the silk fibers in a neutral salt solution, and then dialyzing to remove salt to obtain a 5%-7% silk fibroin solution;

[0037] In the technical solution of the embodiment of the present application, the pretreatment is to cut the cocoons, remove the silkworm pupae and the dirty silk parts inside the cocoons, cut the remaining parts into small pieces, wash them with deionized water, and dry them.

[0038] The boiling degumming process is as follows: the pretreated silk cocoons are placed in deionized water and heated to boil for 30-50 minutes, and then the temperature is maintained at 70-85°C, and the alkali agent is added four times and stirred thoroughly, with an interval of 10 minutes each time; wherein, the total boiling degumming time is 1.5-2 hours, the alkali agents are NaHCO3 and Na2CO3, and the mass ratio of the pretreated silk cocoons to NaHCO3 and Na2CO3 is (18-22):2:1.

[0039] The dialysis time is 3-5 days.

[0040] The neutral salt solution is a lithium bromide aqueous solution, and the concentration of the lithium bromide aqueous solution is 10-12 mol / L.

[0041] The dissolution temperature of silk fiber is 60-70℃, and the dissolution time is 6-8h.

[0042] S2, dissolving dopamine hydrochloride in Tris-HCl buffer to prepare a dopamine solution, mixing the dopamine solution with the silk fibroin solution prepared in step S1, and gently stirring until the mixture is uniform to obtain a mixed solution;

[0043] In the technical solution of the embodiment of the present application, the concentration of Tris-HCl buffer is 5-15 mmol / L, the pH of Tris-HCl buffer is 7.5-8.5, and the concentration of dopamine solution is 1.8-2.2 mg / mL.

[0044] In the mixed solution, the mass ratio of silk fibroin to dopamine is (8-12):1, and the pH value of the mixed solution is 7-8.5.

[0045] In the weakly alkaline mixed solution, dopamine continuously undergoes self-polymerization reaction to form polydopamine with self-adhesive properties. In the subsequent steps, the mixed solution is applied to the surface of the silk fabric to obtain a polydopamine protein coating. Compared with the dopamine protein coating, the polydopamine protein coating has a more stable internal structure and better mechanical properties and wear resistance.

[0046] S3, finishing the silk fabric with the mixed solution obtained in step S2 to obtain a machine-washable silk fabric; wherein the finishing comprises 2-5 padding and baking treatments, wherein the padding and baking treatments are to pad the silk fabric, dry it at 35-45°C, wash it with water, and then bake it at 35-45°C for 5-10 minutes.

[0047] In the technical solution of the embodiment of the present application, the pressure of the rolling mill is 2-3 kg / cm 2 .

[0048] Some specific examples are listed below. It should be noted that the examples described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. Where specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in this area or the product specifications are used. Reagents or instruments used without manufacturer's indication are all commercially available conventional products.

[0049] The silk fabrics used in the examples and comparative examples provided in this application are all 63.3 g / m 2 The plain crepe satin is purchased from Zhejiang Tongxiang Home Textile Co., Ltd. in China.

[0050] Example 1

[0051] This embodiment provides a method for preparing a machine-washable silk fabric, comprising the following steps:

[0052] S1, cut the silk cocoons, remove the pupae, and wash the remaining parts with deionized water to remove surface impurities. Dry the cocoons to obtain pretreated silk cocoons, weigh 20g, place them in deionized water, heat and boil them for 30 minutes, then reduce the temperature to 80°C and keep warm. Add 2g of NaHCO3 and 1g of Na2CO3 in four portions with sufficient stirring, each time with an interval of 10 minutes. After all the alkali agents are added, continue stirring for 30 minutes, pour out the alkali solution, rinse with deionized water, and dry to obtain silk fibers.

[0053] Weigh 18 g of silk fiber and place it in 300 mL of lithium bromide aqueous solution (LiBr, 10-12 mol / L), heat to 65 ° C and stir at this temperature for 6 hours to fully dissolve the silk fiber in the lithium bromide aqueous solution, and then cool naturally. As the temperature of the solution decreases, the originally dissolved silk fibroin crystallizes and precipitates in the saturated solution to obtain a silk fibroin lithium bromide solution. The silk fibroin reaches saturation in the solution. The solution is placed in a dialysis membrane bag, and then the dialysis membrane bag is placed in deionized water and placed at room temperature for 4 days to remove the lithium bromide to obtain a silk fibroin solution with a concentration of 6%.

[0054] S2, dissolving dopamine hydrochloride in 10 mmol / L Tris-HCl buffer (pH = 8.5) to prepare a dopamine solution with a concentration of 2 mg / mL, then mixing the silk fibroin solution prepared in step S1 with the dopamine solution at a solute mass ratio of 10:1, and gently stirring until the mixture is uniform to avoid generating bubbles. The pH of the obtained mixed solution is 8.

[0055] S3, cut a 15cm long and 5cm wide silk fabric, and use the mixed solution prepared in step S2 as a finishing agent to finish the silk fabric. First, the fabric is dipped and rolled twice, with the rolling pressure of 2-3kg / cm 2 Then, the impregnated fabric is placed in a blast oven at 40°C for drying, and the excess finishing agent on the fabric is washed off with clean water. The fabric is placed in the oven again and baked at 40°C for 10 minutes to complete one padding and baking treatment. The padding and baking treatment is repeated twice to obtain a machine-washable silk fabric.

[0056] Examples 2-4 and Comparative Example 1

[0057] The difference between Examples 2-4 and Comparative Example 2 and Example 1 is that in step S3, the number of roll-baking treatments is 3, 4, and 5 times, respectively, as shown in the following table. Other contents are substantially the same as in Example 1 and will not be repeated here.

[0058] project Comparative Example 1 Example 2 Example 3 Example 4 Rolling and baking times (times) 1 3 4 5

[0059] Examples 5-7 and Comparative Examples 2-3

[0060] The difference between Examples 5-7 and Comparative Examples 2-3 and Example 1 is that the baking temperature in step S3 and the second baking time are changed, as shown in the following table. The other contents are roughly the same as Example 1 and are not repeated here.

[0061] project Comparative Example 2 Example 5 Example 6 Example 7 Comparative Example 3 First baking temperature (℃) 25 35 45 45 55 Second baking temperature (℃) 25 35 45 45 55 Second baking time (min) 10 10 10 5 10

[0062] Examples 8-9 and Comparative Examples 4-5

[0063] The difference between Examples 8-9 and Comparative Examples 4-5 and Example 1 is that the mass ratio of silk fibroin to dopamine in step S2 is changed, as shown in the table below. Other contents are roughly the same as Example 1 and will not be repeated here.

[0064] project Example 8 Example 9 Comparative Example 4 Comparative Example 5 Mass ratio of silk fibroin to dopamine 8∶1 12∶1 5∶1 15∶1

[0065] Comparative Example 6

[0066] The difference between Comparative Example 6 and Example 1 is that the pH value of the mixed solution in step S2 is changed to 9.5. The specific steps are as follows: in step S2, 0.5M NaOH solution is added dropwise to the Tris buffer to adjust the pH to 9.5. The rest of the contents are substantially the same as in Example 1 and are not repeated here.

[0067] During the preparation process, since dopamine is not stable enough in an environment with too high a pH value, the solution turns black after dopamine hydrochloride is dissolved in Tris-HCl buffer, causing the machine washable silk fabric coating prepared in Comparative Example 6 to turn black, which is not meaningful for testing.

[0068] The bending length and flexural rigidity of ordinary silk fabrics, machine-washable silk fabrics prepared in Examples 1-9, and Comparative Examples 1-5 were tested with reference to GB / T 18318.1-2009, "Textiles - Determination of Flexural Properties - Part 1: Inclined Plane Method." Each sample group was tested 10 times, and the average of these 10 data points was used as the test result for that group of samples. Details are shown in Tables 1-3.

[0069] Table 1. Effect of the number of pad-baking treatments on the bending properties of silk fabrics

[0070] Fabric Type Rolling and baking times / times Bending length / cm Bending stiffness / (mN·cm) Ordinary silk 0 2.9 0.15 Example 1 2 3.2 0.20 Example 2 3 3.5 0.27 Example 3 4 3.7 0.31 Example 4 5 3.9 0.37 Comparative Example 1 1 3.0 0.17

[0071] Table 2. Effects of baking temperature and time on the bending properties of silk fabrics

[0072]

[0073] Table 3. Effect of the mass ratio of silk fibroin to dopamine on the bending properties of silk fabrics

[0074]

[0075] Referring to Tables 1 to 3, it can be seen that the bending length of the machine washable silk fabrics prepared in Examples 1-9 is between 3.2-3.9 cm, and the bending stiffness is between 0.2-0.37, which are similar to the bending length and bending stiffness of ordinary silk fabrics. This shows that the preparation method of the machine washable silk fabric provided in this application better retains the softness of the silk fabric and has little effect on its wearing performance.

[0076] As shown in Table 1, the bending length and flexural stiffness of machine-washable silk fabrics increase with increasing pad-baking cycles, indicating that coating thickness still has a certain impact on the hand feel of silk. While the hand feel of machine-washable silk fabrics produced with a single pad-baking cycle is closest to that of the original silk fabric, the coating fastness is far inferior to that of fabrics produced with two or more pad-baking cycles. Therefore, to achieve a balance between fabric softness and coating fastness, the number of pad-baking cycles should be controlled between two and five, with two being the optimal number.

[0077] As shown in Table 2, when the baking temperature in step S3 is controlled at approximately 35-45°C and the second baking time is controlled at 5-10 minutes, the softness of the fabric is less affected by the coating, and the coating thickness is uniform, with good fastness. If the temperature is too low, the solvent in the coating evaporates more slowly, which may cause uneven distribution of the coating on the fabric surface and result in higher overall test results. If the temperature is too high, the silk fibroin in the coating and the silk fibers in the fabric will be destroyed, increasing the stiffness of the fabric.

[0078] As shown in Table 3, it can be seen that when the mass ratio of silk fibroin to dopamine in step S2 is set within the range of (8-12):1, the machine washable silk fabric produced can maintain good softness, among which the best mass ratio is 10:1.

[0079] This is because the mass ratio of silk fibroin to dopamine affects the thickness and uniformity of the coating. Silk fibroin is a natural polymer material with strong adhesion and film-forming ability. When the mass ratio of silk fibroin is too high, the concentration of silk fibroin in the finishing solution also increases, which increases the thickness of the coating formed during the treatment process. The membrane structure of the coating is relatively dense, which not only increases the stiffness of the fabric but also affects the breathability of the fabric. Similarly, when the mass ratio of dopamine is too high, the concentration of dopamine in the finishing solution also increases. Dopamine can self-polymerize and form a polymer network under certain conditions. When the dopamine concentration is too high, the coating is prone to form an uneven polymer structure during the curing process. This uneven polymer structure may show different adhesion and thickness in different parts of the fabric, resulting in uneven coating thickness on the fabric surface, making the overall test results higher. In addition, the concentration also affects the interaction between dopamine and silk fibroin. At high concentrations, the interaction between dopamine and silk fibroin is reduced, which may cause the adhesion of the coating to decrease in certain areas, forming defects or weak areas, affecting the durability of machine-washable fabrics.

[0080] Application Example 1

[0081] Ordinary silk fabric and the machine washable silk fabric prepared in Example 1 were washed 30 times in a washing fastness tester at 45°C under the conditions of 150 mL of commercial detergent (concentration of 0.15 wt%) and 50 steel balls, each washing for 45 minutes, to explore the washability of the silk fabric.

[0082] See also Figure 1 As shown, (a), (b), (c), and (d) are electron micrographs of the fibers of ordinary silk fabric after washing 30 times, and (e), (f), (g), and (h) are electron micrographs of the fibers of the machine-washable silk fabric prepared in Example 1 after washing 30 times. It can be seen that the surface of the uncoated silk fabric becomes relatively rough after 30 machine washes, and many tiny damages and burrs appear on the surface of the silk fibers, which are caused by mechanical friction and water flow impact during the machine washing process; while the surface of the silk fabric with polydopamine protein coating does not undergo obvious changes after 30 machine washes, and there are no obvious damages and burrs on the surface of the silk fibers, which indicates that the machine-washable silk fabric provided by the present application has excellent washing resistance.

[0083] The apparent colors of ordinary silk fabric and the machine washable silk fabric prepared in Example 1 are as follows: Figure 2 As shown, it can be seen that the two have similar colors, indicating that the preparation method of the machine washable silk fabric provided by the present application relatively effectively retains the color and natural luster of the fabric.

[0084] In summary, the machine washable silk fabric provided by the present application utilizes hydrogen bonds between polydopamine, silk fibroin and silk fabric, as well as multiple electrostatic forces, to improve the mechanical strength, friction resistance and washability of the silk fabric without changing the softness and comfort of the silk fabric itself, thereby extending its service life.

[0085] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and within the scope of the technical solution of the present application, embodiments having substantially the same structure as the technical concept and exerting the same effects are all included in the technical scope of the present application. In addition, within the scope of the subject matter of the present application, various modifications that can be conceived by those skilled in the art to the embodiments, and other methods constructed by combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for preparing machine-washable silk fabric, characterized in that: The following steps are involved: S1, boiling and degumming the pretreated silk cocoons, washing with deionized water, and drying to obtain silk fibers, dissolving the silk fibers in a neutral salt solution, and then dialyzing to remove salt to obtain a silk fibroin solution; S2, dissolving dopamine hydrochloride in Tris-HCl buffer to prepare a dopamine solution, mixing the dopamine solution with the silk fibroin solution prepared in step S1, and gently stirring until the mixture is uniform to obtain a mixed solution; S3, using the mixed solution obtained in step S2 to finish the silk fabric to obtain a machine-washable silk fabric; wherein the finishing includes 2-5 padding and baking treatments, wherein the padding and baking treatments are to pad the silk fabric, dry it at 35-45°C, wash it with water, and then bake it at 35-45°C for 5-10 minutes.

2. The method for preparing machine-washable silk fabric according to claim 1, wherein: In step S2, the concentration of the Tris-HCl buffer is 5-15 mmol / L, the pH of the Tris-HCl buffer is 7.5-8.5, and the concentration of the dopamine solution is 1.8-2.2 mg / mL.

3. The method for preparing a machine-washable silk fabric according to claim 2, wherein: In step S2, in the mixed solution, the mass ratio of silk fibroin to dopamine is (8-12):1, and the pH of the mixed solution is 7-8.

5.

4. The method for preparing machine-washable silk fabric according to claim 1, wherein: In step S1, the boiling degumming is to place the pretreated cocoons in deionized water and heat them for 30-50 minutes, then maintain the temperature at 70-85°C, add an alkali agent in four times and stir thoroughly, each time with an interval of 10 minutes; wherein the total duration of the boiling degumming is 1.5-2 hours, the alkali agent is NaHCO3 and Na2CO3, and the mass ratio of the pretreated cocoons to NaHCO3 and Na2CO3 is (18-22):2:

1.

5. The method for preparing machine-washable silk fabric according to claim 4, characterized in that: In step S1, the neutral salt solution is a lithium bromide aqueous solution, and the concentration of the lithium bromide aqueous solution is 10-12 mol / L.

6. The method for preparing machine-washable silk fabric according to claim 5, characterized in that: In step S1, the pretreatment is to cut the cocoons, remove the silkworm pupae and the dirty silk parts inside the cocoons, cut the remaining parts into small pieces, wash them with deionized water, and dry them.

7. The method for preparing machine-washable silk fabric according to claim 6, characterized in that: In step S1, the dissolution temperature of the silk fiber is 60-70° C., and the dissolution time is 6-8 hours.

8. The method for preparing machine-washable silk fabric according to claim 7, wherein: In step S1, the dialysis time is 3-5 days.

9. The method for preparing machine-washable silk fabric according to claim 1, wherein: In step S3, the pressure of the roller is 2-3 kg / cm 2 .

10. A machine washable silk fabric, characterized in that: The machine washable silk fabric Prepared according to the preparation method described in any one of claims 1 to 9.

Images