Machine-washable real silk fabric and preparation method thereof

Abstract

The invention provides a preparation method of a machine-washable real silk fabric, which comprises the following steps: cleaning silkworm cocoons, boiling for degumming, washing with water, drying to obtain silk fibers, dissolving the silk fibers in a neutral salt solution, and dialyzing to obtain a silk fibroin solution; then, preparing a dopamine solution, and uniformly mixing the dopamine solution with the silk fibroin solution to obtain a mixed solution; and finally, carrying out rolling and baking treatment on the real silk fabric with the mixed solution by adopting a technological process of padding, baking, washing and re-baking, and carrying out rolling and baking treatment for 2-5 times to obtain the machine-washable real silk fabric. According to the application, the polydopamine protein coating with good biocompatibility is adopted, and hydrogen bonds among polydopamine, silk fibroin and the real silk fabric and various electrostatic acting forces are utilized, so that the mechanical strength, friction resistance and washing / machine washing resistance of the real silk fabric are improved while the softness and comfort of the real silk fabric are not changed, and the service life of the real silk fabric is prolonged. The nursing convenience and the service life are prolonged.

Description

Technical Field

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

[0002] Silk fiber has good biocompatibility. The silk fabric made of silk fiber as raw material has a smooth and glutinous feel, is soft and skin-friendly, has good air permeability and moisture permeability, and has good drape. It is a representative high-end fabric in the field of textiles and clothing. However, silk fiber is relatively fragile in a wet state. At this time, its mechanical properties and chemical resistance (such as detergents) are poor, and it is easily damaged and deformed. 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 washing resistance of silk fabrics.

[0003] In the existing technology, some researchers have improved 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 anti-dust damage performance of silk fabrics, but its hydrophilicity has significantly deteriorated and the feel has significantly become 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 easy to cause fiber loss, but also affects the color of the fabric.

[0004] In general, most of the current finishing methods can give silk fibers excellent functional properties, but there are few studies on the machine washability of silk fabrics. Although there are a few reports that some methods can improve the machine washability of silk fabrics, they often sacrifice the fabric's feel, gloss, color, and moisture absorption and moisture retention. In view of this, it is necessary to design a machine washable silk fabric and its preparation method to solve the above problems. Summary of the invention

[0005] The present application provides a machine-washable silk fabric and a preparation method thereof, aiming to solve the problem that the existing machine-washable finishing method is not environmentally friendly and causes the loss of the hand feel, gloss, moisture absorption and moisture retention of the silk fabric. 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 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 the mechanical strength and wear resistance are greatly improved, and the service life is extended. After 30 machine washes, there is no obvious damage and 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 and desalting to obtain a silk fibroin solution;

[0008] S2, dissolving dopamine hydrochloride in a 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, and 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 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, and cut the remaining parts into small pieces and 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 that the existing machine-washable finishing method in the background art is not environmentally friendly and will cause the loss of the hand feel, gloss, moisture absorption and moisturizing performance of the silk fabric. 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 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 the mechanical strength and wear resistance are greatly improved, and the service life is extended. After 30 machine washes, there is no obvious damage and 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, retaining 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 uses 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 the present application has the same biological source 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 gloss 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 the present 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 fibroin and dopamine mixed solution, dopamine continuously undergoes oxidation self-polymerization reaction to form polydopamine, and the polydopamine structure is similar to mussel adhesion protein, and has self-adhesion characteristics, which allows it to be firmly attached to the surface of silk. At the same time, multiple hydroxyls and amines in the molecular structure of polydopamine form hydrogen bonds and other non-covalent bonds with hydroxyls and amines on the surface of fibroin, so that the interaction between polydopamine and fibroin is enhanced, 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 multiple forces exist between polydopamine, fibroin and silk fabric, which are coordinated with each other, so that the interfacial bonding force between polydopamine protein coating and silk fabric is greatly enhanced, the mechanical strength and wear resistance of silk fabric are improved, and its service life is extended.

[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, such as titanium dioxide nanoparticles, zinc oxide nanoparticles, rose essential oil, and peppermint essential oil, to the mixed solution used for padding, the machine washable silk fabrics can be made to have anti-ultraviolet, soothing, and refreshing effects. 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] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

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

[0028] Figure 2 1 is a comparison diagram of the apparent colors 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 are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used 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 technicians in the technical field 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" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0031] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0032] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood 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 the present application, the term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0034] In order to solve the problem that the existing machine wash-resistant finishing method is not environmentally friendly and will cause the loss of the feel, gloss and moisture absorption and moisturizing performance of the silk fabric, 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 among 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 wash resistance.

[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 silk fibroin solution with a concentration of 5%-7%;

[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, 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 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 a 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 internal structure of the polydopamine protein coating is more stable, and the mechanical properties and wear resistance are better.

[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 embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used that do not specify the manufacturer are all conventional products that can be obtained commercially.

[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 cocoons, remove the silkworm pupae, wash the rest with deionized water to remove surface impurities, dry to obtain the pretreated cocoons, weigh 20g, heat and boil in deionized water for 30 minutes, reduce the temperature to 80°C and keep warm, add 2g NaHCO3 and 1g Na2CO3 four times and stir well, 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, dry to obtain silk fibers.

[0053] Weigh 18g of silk fiber and put it into 300mL of lithium bromide aqueous solution (LiBr, 10-12mol / L), heat to 65°C and stir at this temperature for 6h to make the silk fiber fully dissolved in the lithium bromide aqueous solution, and then cool naturally. As the temperature of the solution decreases, the originally dissolved silk fibroin crystallizes in the saturated solution to obtain a silk fibroin lithium bromide solution. The silk fibroin reaches saturation in the solution. The solution is loaded into 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 10mmoL / L Tris-HCl buffer (pH=8.5) to prepare a dopamine solution with a concentration of 2mg / 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, and 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, and the rolling pressure is 2-3kg / cm 2 The impregnated fabric is then dried in a blast oven at 40°C, excess finishing agent on the fabric is washed off with clean water, and the fabric is placed in an oven again and baked at 40°C for 10 minutes, completing 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. The other contents are substantially the same as those 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 time of the second baking are changed, as shown in the following table. The other contents are roughly the same as Example 1 and will not be 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 following table. The other contents are substantially the same as those in 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, and the specific steps are: in step S2, 0.5M NaOH solution is added dropwise to the Tris buffer to adjust the pH to 9.5. The other contents are substantially the same as those in Example 1 and will not be repeated here.

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

[0068] With reference to GB / T18318.1-2009 "Determination of flexural properties of textiles - Part 1: Inclined plane method", 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. Each group of samples was tested 10 times, and the average of the 10 data was taken as the test result of the group of samples, as shown in Tables 1-3.

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

[0070] Fabric Type Rolling and baking 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 baking 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] Please refer 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 the present application better retains the softness of the silk fabric and has little effect on its wearing performance.

[0076] As shown in Table 1, it can be seen that with the increase in the number of pad-baking treatments, the bending length and bending stiffness of the machine washable silk fabric have a tendency to increase, indicating that the thickness of the coating still has a certain influence on the hand feel of the silk. The hand feel of the machine washable silk fabric obtained by pad-baking treatment once is closest to the original silk fabric, but its coating fastness is far less than that of the machine washable silk fabric obtained by pad-baking treatment twice or more. Therefore, in order to balance the softness of the fabric and the coating fastness, the number of pad-baking treatments should be controlled between 2-5 times, and 2 times is the best.

[0077] As shown in Table 2, it can be seen that when the baking temperature in step S3 is controlled at about 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 and the fastness is good. If the temperature is too low, the solvent in the coating evaporates slowly, which may cause the coating to be unevenly distributed on the fabric surface, making the overall test result higher; if the temperature is too high, the silk fibroin in the coating and the silk fiber in the fabric will be destroyed, and the stiffness of the fabric will increase.

[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, and the film structure of the coating is relatively dense, which not only increases the stiffness of the fabric, but also affects the air permeability 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 concentration of dopamine 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 high. In addition, concentration will also affect 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 min, to explore the washability of the silk fabric.

[0082] See also Figure 1 As shown, (a), (b), (c), (d) are the electron microscope images of the fibers of the ordinary silk fabric after washing 30 times, and (e), (f), (g), (h) are the electron microscope images 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 silk fabric without coating becomes rougher after 30 machine washings, 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 silk fabric with polydopamine protein coating has no obvious changes on its surface after 30 machine washings, and there is no obvious damage and burrs on the surface of the silk fibers, which shows 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 in 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 the 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 only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of 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 a 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 and desalting to obtain a silk fibroin solution; S2, dissolving dopamine hydrochloride in a 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, and 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, characterized in that: 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 machine washable silk fabric according to claim 2, characterized in that: 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, characterized in that: 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 four times and stir them 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, and cut the remaining parts into small pieces and 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 6-8h.

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

9. The method for preparing machine washable silk fabric according to claim 1, characterized in that: In step S3, the pressure of the rolling mill 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.

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