Preparation method and application of polyurethane colored film composite functional silk textile

Abstract

The application discloses a preparation method and application of polyurethane colored film composite functional silk textile, and the polyurethane colored film composite functional silk textile is prepared by taking silk fabric as a base, taking polyurethane as a dispersant and a stabilizer, taking chitin microcrystal as a crosslinking agent, and taking dopamine as a reducing agent, and in-situ synthesizing metal nanoparticles which are deposited on the silk fabric together. The obtained polyurethane colored film composite silk fabric has good wrinkle resistance, ultraviolet resistance, flame resistance and strength.

Description

Technical Field

[0001] This invention belongs to the field of textile technology, specifically relating to a method for preparing and applying polyurethane colored film composite functional silk textiles. Background Technology

[0002] Polyurethane is an organic polymer material whose molecular structure can be designed. Due to its excellent properties, it is widely used in coatings, adhesives, foams, elastomers, fibers, and other fields. Waterborne polyurethane (WPU) uses water as a solvent to disperse polyurethane prepolymers containing isocyanate functional groups directly or through a reverse emulsification process into water to form WPU. It has advantages such as being pollution-free, safe and reliable, easy to modify, having excellent mechanical properties, and good compatibility.

[0003] This invention uses polyurethane as a dispersant and stabilizer, and dopamine as a reducing agent to synthesize metal nanoparticles in situ and deposit them on fabrics to prepare functional textiles with different colored structures. It is hoped that multifunctional textiles with flame retardancy, wrinkle resistance, and UV protection can be obtained through a simple approach. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments.

[0005] As one aspect of the present invention, the present invention provides a method for preparing polyurethane colored film composite functional silk textiles, which comprises the following steps:

[0006] (1) Preparation of chitin microcrystals: Chitin was placed in a light-proof container, sodium periodate solution was added, and the mixture was oxidized by shaking under light-proof conditions. Ethylene glycol was added to react, the mixture was filtered, barium acetate was added, acetone was added, the mixture was allowed to stand, and the precipitate was dried to obtain chitin microcrystals.

[0007] (2) Preparation of metal ion solutions;

[0008] (3) Preparation of colored sol: Add the aqueous polyurethane dispersion to water, add the metal ion solution under stirring, add the chitin microcrystals, add dopamine, stir, and obtain colored sol;

[0009] (4) Preparation of colored sol composite textiles: Immerse the silk fabric in the colored sol prepared in step (3), shake at room temperature, take it out, wash with water, and dry.

[0010] As a preferred embodiment of the preparation method of polyurethane colored film composite functional silk textiles of the present invention: In step (1), 3g of chitin is placed in a light-proof container, 120ml of 0.3mol / L sodium periodate solution is added, and the mixture is oxidized by vibration at 30°C for 2 hours in the light-proof environment. Then, 20ml of 0.1mol / L ethylene glycol is added and reacted for 0.5 hours. The mixture is filtered, barium acetate is added, acetone is added, and the mixture is allowed to stand. The precipitate is then dried to obtain chitin microcrystals.

[0011] As a preferred embodiment of the preparation method of polyurethane colored film composite functional silk textiles of the present invention: in step (1), 3-5 ml of 1.5 mmol / L barium acetate is added.

[0012] As a preferred embodiment of the preparation method of polyurethane colored film composite functional silk textiles of the present invention: in step (1), 120 ml of acetone is added and left to stand for 5 hours.

[0013] As a preferred embodiment of the preparation method of polyurethane colored film composite functional silk textiles of the present invention: in step (2), the metal ion solution is a 0.02 mol / L AgNO3 aqueous solution.

[0014] As a preferred embodiment of the preparation method of polyurethane colored film composite functional silk textiles of the present invention: In step (3), 10 mL of aqueous polyurethane dispersion with a solid content of 60 wt% is added to 30 mL of water, 10 mL of the metal ion solution is added under stirring, 0.1 g of the chitin microcrystals are added, and then 0.1 g of dopamine is added. After stirring for 2 hours, colored sol is obtained.

[0015] As a preferred embodiment of the preparation method of polyurethane colored film composite functional silk textiles of the present invention: in step (4), the room temperature shaking time is 1 hour.

[0016] As a preferred embodiment of the preparation method of polyurethane colored film composite functional silk textiles of the present invention: in step (1), the sodium periodate solution is an aqueous solution of sodium periodate.

[0017] The beneficial effects of this invention are as follows: This invention uses silk fabric as a substrate, polyurethane as a dispersant and stabilizer, chitosan microcrystals as a crosslinking agent, and dopamine as a reducing agent to synthesize metal nanoparticles in situ, which are then co-deposited onto the silk fabric to prepare a polyurethane colored film composite functional textile. The obtained polyurethane colored film composite silk fabric has good wrinkle resistance, UV resistance, flame retardancy, and strength. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0019] Figure 1 The K / S values ​​of fabrics after different treatment methods.

[0020] Figure 2 The reflectance of the fabric after different treatment methods.

[0021] Figure 3 Silk fabric treated with WSK / DA+ZnSO4.

[0022] Figure 4 Silk fabric treated with WSK / DA+FeCl3.

[0023] Figure 5 Silk fabric treated with WSA / DA+AgNO3.

[0024] Figure 6 The stress-strain curves of silk fabrics before and after treatment with dopamine / microcrystals / metal ions are shown.

[0025] Figure 7 The K / S values ​​of fabrics after different treatment methods.

[0026] Figure 8 The reflectance of the fabric after different treatment methods.

[0027] Figure 9 Silk is treated with WSK / DA+PU+ZnSO4.

[0028] Figure 10 Silk treated with WSK / DA+PU+FeCl3.

[0029] Figure 11 Silk is treated with WSK / DA+PU+AgNO3.

[0030] Figure 12 The stress-strain curves of silk fabrics before and after treatment with PU / dopamine / microcrystalline / metal ions are shown.

[0031] Figure 13 The K / S value of silk before and after treatment with PU / dopamine / microcrystals / Ag ions under alkaline conditions.

[0032] Figure 14 The R / T value is the value of silk before and after treatment with PU / dopamine / microcrystals / Ag ions under alkaline conditions.

[0033] Figure 15 Silk fabric treated with PU / dopamine / microcrystalline / Ag ions in an alkaline environment.

[0034] Figure 16 The stress-strain curves of silk fabrics before and after treatment with PU / dopamine / microcrystalline / Ag ions in an alkaline environment are shown.

[0035] Figure 17 This is a schematic diagram illustrating the preparation of chitin microcrystals.

[0036] Figure 18 This is a schematic diagram of the self-polymerization mechanism of dopamine. Detailed Implementation

[0037] To make the above-mentioned objectives, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to specific examples.

[0038] Chitin and biochemical reagent BR were purchased from Shanghai Zhanyun Chemical Co., Ltd., and chitosan was purchased from Sinopharm Chemical Reagent Co., Ltd.

[0039] (1) Preparation of chitin microcrystals: 3g of chitin was placed in a cylinder packaged with aluminum foil, and 120ml of 0.3mol / L sodium periodate aqueous solution was added. The mixture was oxidized by vibration in the dark at 30℃ for 2 hours. Then, 20ml of 0.1mol / L ethylene glycol was added and the reaction was allowed to proceed for 0.5 hours. The unreacted impurities in the solution were removed by filtration. 4ml of 1.5mmol / L barium acetate aqueous solution was added to the filtrate. Excess Ba5(IO6)2 was filtered out. Then, 120ml of acetone was added to the filtrate. The mixture was allowed to stand for 5 hours to allow the product to precipitate. The product was then dried to obtain chitin microcrystals. Figure 17 This is a schematic diagram illustrating the preparation of chitin microcrystals.

[0040] (2) Preparation of AgNO3, ZnSO4 and FeCl3 metal ion solutions: Prepare aqueous solutions of AgNO3, ZnSO4 and FeCl3 with a concentration of 0.02 mol / L respectively.

[0041] (3) Preparation of PU / PDA / M+ colored sol containing different metal ions: Take 10 mL of aqueous polyurethane dispersion with a solid content of 60 wt% and add it to 30 mL of distilled water. Under magnetic stirring, gradually add 10 mL of different metal ion solutions and 0.1 g of chitin microcrystals. After the mixture is completely dissolved by magnetic stirring, continue to add 0.1 g of dopamine and stir magnetically for 2 hours.

[0042] (4) Preparation of PU / PDA / M + colored sol composite textiles: Cut silk fabric into 10cm*10cm pieces.2 The block is immersed in the colored sol prepared in step (3), shaken at room temperature for 1 hour, removed, washed with water, and dried.

[0043] Figure 18 This is a schematic diagram of the self-polymerization mechanism of dopamine.

[0044] UV protection performance determination: After turning on the equipment for 10 minutes, click on the YG(B)912 Textile UV Protection Performance Testing System on the desktop, create a new file on the system's main interface, and access the functions. Close the parameters and save. Open the main menu "Control Tools" and select "Clear Tool" to begin exploring unused modes. When the test is complete, insert a sample, and save the test data to the created folder. Weigh each piece of fabric evenly.

[0045] Surface color depth measurement: After the equipment has been preheated for 15 minutes, install the computer terminal simulation software and begin measuring the equipment using a light trap and a white board. Place a piece of silk fabric under the observation window and use the Color-Eye7000A computer color matching system to measure color depth K / S, reflectance R / T, and color contrast data such as L*, a*, and b* lip values. L* represents light, a* represents red-green, and b* represents yellow-blue. Each fabric can be tested multiple times and rated.

[0046] Wrinkle resistance test: The vertical method involves samples that bulge outwards. During the test, the sample is vertically folded at the fold line and placed in a chuck on the test table, then supported by a glass slide. Pressure is then applied to the glass slide, and after a period of release, the pressure is removed. The test table is then verticalized, and an inclinometer is used to read the unfolding angle between the two opposing planes of the sample. This angle is called the fold recovery angle. Generally, the recovery angle after a shorter time (15 seconds) is called the rapid elasticity recovery angle, while the recovery angle after a longer time (5 minutes) is called the slow elasticity fold recovery angle.

[0047] Tensile property test: This experiment uses the strip tearing method, in which a 10×10cm sample to be tested is cut into strips 2cm wide and 10cm long and clamped entirely in the upper and lower clamps of the tensile testing machine. The test is conducted using a micro-controlled electronic universal testing machine (model CMT4304), and the obtained data is recorded.

[0048] Flame retardant performance test: Before testing, draw a mark 50mm away from the ignition point, then install it vertically on the sample holder, ensuring the distance between it and the combustion chamber exceeds 10mm. Estimate the initial oxygen content and adjust accordingly. Maintain a flow rate of 40±10 mm / s in the combustion chamber under all conditions. Allow the adjusted airflow for 30 seconds to clean the fuel tank. Then, ignite the top of the sample with an igniter. Once all samples are ignited, remove the igniter and start timing. Do not arbitrarily adjust the flow rate or oxygen content at this time. If the sample continues to burn for more than 3 minutes during the experiment, or if a flame peak appears at the mark, the oxygen content must be reduced to a minimum. Conversely, the oxygen content should be increased. When the difference in oxygen content is adjusted to less than 0.5%, the oxygen index should be determined by the decrease in oxygen content. Three tests are conducted in this area.

[0049] The formula for calculating the oxygen index (OI) is: OI = [O2] / [O2] + [N2] × 100%

[0050] In the formula, [O2] represents the oxygen flow rate in L / min; [N2] represents the nitrogen flow rate in L / min. The average value of the three test results is the oxygen index of the material.

[0051] Preparation of PU metal ion colored textiles:

[0052] Dopamine / microcrystalline / metal ion treated silk fabrics:

[0053] The effects of different metal ion doping and modification deposition on the properties of pretreated silk were studied. The surface color depth value (K / S), reflectance-transmittance (R / T), and UV resistance factor (UPF) of the silk were measured. The surface color depth value (K / S) is shown in the figure. Figure 1 Reflectance transmittance R / T such as Figure 2 The values ​​of L*, a*, and b* are shown in Table 1, and the UV resistance coefficient UPF values ​​are shown in Table 2. Figure 1 The K / S values ​​of fabrics after different treatment methods. Figure 2 The table shows the reflectance of fabrics after different treatments. WSK in the table represents chitosan microcrystals, and DA represents dopamine.

[0054] Table 1. L*, a*, and b* values ​​of fabrics treated by different methods

[0055] Name L＊ a＊ b＊ Original fabric 93.04 3.24 -6.25 WSK / DA + ZnSO4 32.29 3.66 9.01 WSK / DA + AgNO3 41.52 4.93 13.2 WSK / DA + FeCl3 39.14 3.31 14.32

[0056] Table 2 UPF values ​​of fabrics treated by different methods

[0057] method UVA UVB UPF Original fabric 0.7 2.93 102.35 WSK / DA + ZnSO4 0.59 1.06 173.21 WSK / DA + AgNO3 0.34 1.86 255.31 WSK / DA + FeCl3 0.65 2.27 167.68

[0058] Depend on Figure 1It is known that the K / S ratio of treated silk fabrics is larger than that of untreated silk. The surface color depth value (K / S) of silk fabrics treated with WSK / DA+ZnSO4 is greater than that treated with WSK / DA+FeCl3, while the surface color depth value (K / S) of silk fabrics treated with WSK / DA+FeCl3 is greater than that treated with WSA / DA+AgNO3. The reason may be that the addition of chitosan microcrystals can effectively promote the oxidative polymerization of DA, rapidly forming a black polydopamine layer on the fiber surface. The hydroxyl and amino groups contained in the polydopamine layer can further coordinate with metal ions, enhancing the adhesion of the fiber surface and other functions. Zn... 2+ Fe 3+ and Ag + In aqueous solutions of water-based polyurethane / chitosan microcrystals / dopamine, the silk fabric is more easily adsorbed, and after treatment with metal particles, the color of the silk fabric darkens. Figure 2 It can be seen that the R / T of treated silk fabrics is smaller than that of untreated silk. The silk fabric treated with WSK / DA+ZnSO4 has the lowest reflectance and transmittance, followed by the one treated with WSK / DA+FeCl3. The reflectance and transmittance of untreated silk fabric is much higher than that of treated fabric. After treatment with metal particles, the silk fabric adsorbs the metal particles, causing them to deposit on the fabric surface. Zn 2+ Particles are most easily adsorbed by silk, therefore Zn 2+ The particle coverage on the silk surface is the highest, thus reducing the reflectivity and transmittance of the silk fabric. The higher the metal ion coverage on the silk fabric surface, the lower the reflectivity and transmittance. Table 1 shows that the L*, a*, and b* values ​​are different for different treatment methods. L* represents brightness; a higher value indicates greater brightness. The decrease in the L* value after treatment is due to the deposition of a colored hybrid film, thus reducing brightness. Furthermore, the a* value remains positive and shows little difference before and after treatment, indicating that the treatment does not affect the reddish tint of the silk. However, the b* value changes from negative to positive after treatment, indicating that the treated silk changes from a bluish to a yellowish tint. Table 2 shows that the shielding coefficient of the silk treated with metal particles is significantly increased, indicating that after the silk fabric adsorbs metal ions, the metal particles have an adsorption and reflection effect on light. The UPF value of silk fabrics treated with WSA / DA+AgNO3 was significantly higher than that of silk fabrics treated with WSK / DA+ZnSO4 and WSK / DA+FeCl3. This is because the polydopamine coating itself has excellent UV resistance, and the catechol groups contained in PDA can block AgNO3. + The reduction to Ag nanoparticles further promotes the absorption of ultraviolet light. The other two ions only have metal coordination bonds with the hydroxyl and amino groups of dopamine.

[0059] The physical characteristics of silk fabrics treated with WSK / DA+ZnSO4 are as follows: Figure 3 As shown, the external characteristics of silk fabrics treated with WSK / DA+FeCl3 are as follows: Figure 4 As shown, the external characteristics of silk fabrics treated with WSA / DA+AgNO3 are as follows: Figure 5 As shown. Figure 3 Silk fabric treated with WSK / DA+ZnSO4. Figure 4 Silk fabric treated with WSK / DA+FeCl3. Figure 5 Silk fabric treated with WSA / DA+AgNO3.

[0060] Table 3. Rapid and slow elastic wrinkle recovery angles of silk fabrics before and after dopamine / microcrystalline / metal ion treatment.

[0061]

[0062]

[0063] Table 3 shows that the treated silk fabric exhibited improved rapid and slow elastic wrinkle recovery angles, resulting in enhanced wrinkle resistance. This is attributed to the surface polymerization of polydopamine, which forms a polymer film on the fabric surface, enhancing its elasticity and restricting the relative slippage of fiber molecular chains, thus contributing to improved overall wrinkle resistance. Silver nitrate, as a metal source, significantly increased the wrinkle recovery angle, possibly because silver ions can coordinate with amino and carboxyl groups on the silk fabric surface, strengthening the connection points between molecular chains and further contributing to improved wrinkle resistance. Figure 6 The stress-strain curves of silk fabrics before and after treatment with dopamine / microcrystals / metal ions are shown.

[0064] Table 4. Tensile properties of silk fabrics before and after dopamine / microcrystalline / metal ion treatment.

[0065] Elongation at break (%) Elastic modulus (MPa) Original fabric 31.76 418.54 WSK / DA + AgNO3 23.9 415.28 WSK / DA + FeCl3 23.61 527.8 WSK / DA + ZnSO4 21.58 543.3

[0066] Depend on Figure 6 It can be seen that after the chitin microcrystalline dopamine surface polymerization and the reduction deposition of metal ions, the strength of the silk fabric is increased compared to the untreated fabric. As shown in Table 4, the elongation at break of the silk fabric treated with dopamine / microcrystalline / metal ion is smaller and the elastic modulus is increased, indicating that the elasticity of the silk fabric is reduced and the rigidity is increased.

[0067] Table 5 Flame retardant properties of silk fabrics before and after dopamine / microcrystalline / metal ion treatment.

[0068] sample Limiting oxygen index (%) Original fabric 23.10 WSK / DA + AgNO3 27.56 WSK / DA + FeCl3 24.80 WSK / DA + ZnSO4 25.52

[0069] Table 5 shows that the limiting oxygen index (LOI) of untreated silk fabric is 23.10%, while that of WSK / DA+AgNO3 treated fabric is 27.56%, WSK / DA+FeCl3 treated fabric is 24.80%, and WSK / DA+ZnSO4 treated fabric is 25.52%. It can be seen that the LIOI increases after treatment. This is because the treated silk fabric is covered with metal ions, forming an insulating layer on the fiber surface during combustion, blocking contact with oxygen and improving the flame retardant properties of the silk. It can also be seen that the WSK / DA+AgNO3 treated silk exhibits the best flame retardant properties.

[0070] PU / Dopamine / Microcrystalline / Metal Ion Treatment of Silk Fabrics: This study investigated the effects of dopamine / microcrystalline / metal ions on the surface properties of silk in the presence of polyurethane polymers. The surface color depth value (K / S), reflectance-transmittance (R / T), and UV resistance factor (UPF) were measured. The surface color depth value (K / S) is shown below. Figure 7 Reflectance transmittance R / T such as Figure 8 The values ​​of L*, a*, and b* are shown in Table 5, and the UV resistance coefficient UPF values ​​are shown in Table 6. Figure 7 The K / S values ​​of fabrics after different treatment methods. Figure 8 The reflectance of the fabric after different treatment methods.

[0071] Table 6. L*, a*, and b* values ​​of fabrics treated by different methods.

[0072] Name L＊ a＊ b＊ Original fabric 93.18 3.12 -6.39 WSK / DA+PU+ZnSO4 55.06 1.65 1.81 WSK / DA+PU+AgNO3 62.26 -0.15 2.45 WSK / DA+PU+FeCl3 74.9 3 0.27

[0073] Figure 9 Silk is treated with WSK / DA+PU+ZnSO4. Figure 10 Silk treated with WSK / DA+PU+FeCl3. Figure 11 Silk is treated with WSK / DA+PU+AgNO3.

[0074] In the process of treating silk fabrics with WSK / DA+PU+ZnSO4, WSK / DA+PU+AgNO3, and WSK / DA+PU+FeCl3, a small amount of solids appeared upon the addition of metal ion solutions. Even after re-preparing the reaction solution and slowly adding the metal ion solution dropwise while stirring with a magnetic stirrer, clumps of solids still formed. It is understood that waterborne polyurethane is anionic, while the metal ion solutions are acidic. In an acidic environment, polyurethane is in molecular form with very low water solubility. Therefore, when the metal ion solution is added dropwise, the metal ions react with the waterborne polyurethane to form a solid macromolecular polymer. Figure 7It can be seen that the color depth values ​​of silk fabrics treated with WSK / DA+PU+ZnSO4, WSK / DA+PU+AgNO3, and WSK / DA+PU+FeCl3 are slightly larger than those of the original fabric. This is not the result of metal ions; rather, under the action of chitosan microcrystals, dopamine undergoes oxidative polymerization, rapidly forming a black polydopamine layer on the surface of the silk fibers. This is the reason for the increased color depth values ​​on the treated silk fabric surface. Figure 8 It can be seen that the reflectance transmittance of the silk fabric treated with WSK / DA+PU+ZnSO4, WSK / DA+PU+AgNO3, and WSK / DA+PU+FeCl3 still decreased, indicating that some metal ions were still deposited on the surface of the silk fabric.

[0075] Table 7. Rapid and slow elastic wrinkle recovery angles of silk fabrics before and after PU / dopamine / microcrystalline / metal ion treatment.

[0076]

[0077] As shown in Table 7, the rapid and slow elastic wrinkle recovery angles of silk fabrics treated with polyurethane after adding the colored solution of metal ions increased significantly, indicating a substantial improvement in the wrinkle resistance of the fabrics. In particular, the silk fabrics treated with the addition of Ag ions exhibited the best wrinkle resistance. This demonstrates that the addition of polyurethane significantly enhances wrinkle resistance. Figure 12 The stress-strain curves of silk fabrics before and after treatment with PU / dopamine / microcrystalline / metal ions are shown.

[0078] Table 8. Tensile properties of silk fabrics before and after PU / dopamine / microcrystalline / metal ion treatment

[0079] Elongation at break (%) Elastic modulus (MPa) Original fabric 31.76 418.54 PU / WSK / DA+AgNO3 43.5 706.61 PU / WSK / DA + FeCl3 38.78 162.58 PU / WSK / DA+ZnSO4 55 428.6

[0080] Depend on Figure 12 As shown in Table 8, the elongation at break of silk fabrics treated with PU / dopamine / microcrystalline / metal ions all increased, indicating that the elasticity of the fabrics was greatly improved after polyurethane treatment. Except for the silk treated with PU / WSK / DA+FeCl3, whose elastic modulus decreased significantly, the other two treatments showed an increase, especially the silk treated with PU / WSK / DA+AgNO3, whose elastic modulus was 288.07 MPa higher than the untreated silk. This indicates that the PU / WSK / DA+AgNO3 treatment had the best strength-enhancing effect on the silk.

[0081] Table 9 Flame retardant properties of silk fabrics before and after PU / dopamine / microcrystalline / metal ion treatment.

[0082]

[0083]

[0084] Table 9 shows that the limiting oxygen index (LOI) of untreated silk fabric is 23.10%, while that of PU / WSK / DA+AgNO3 treated fabric is 30.12%, PU / WSK / DA+FeCl3 treated fabric is 25.34%, and PU / WSK / DA+ZnSO4 treated fabric is 26.87%. It can be seen that the LIOI of all treated fabrics shows an increasing trend. This is because the treated silk fabric is covered with metal ions, forming an insulating layer on the fiber surface during combustion, blocking contact with oxygen and improving the flame retardant properties of the silk. Furthermore, the addition of polyurethane results in higher flame retardant properties than the fabric without polyurethane, indicating that the addition of polyurethane provides a more effective coating of the fabric surface with a colored polyurethane metal ion film, further enhancing oxygen isolation during combustion. It can also be seen that the PU / WSK / DA+AgNO3 treated silk fabric exhibits the best flame retardant properties.

[0085] Silk fabrics treated with PU / dopamine / microcrystalline / Ag ions under alkaline conditions: Based on the above experimental results, it is known that anionic waterborne polyurethane and acidic metal ion solutions react together. It is hypothesized that alkaline conditions may yield ideal results. ZnSO4 solution and FeCl3 solution readily react with OH- to form precipitates under alkaline conditions. Using dopamine as a reducing agent and PU as a dispersant under alkaline conditions, silver ions can be effectively reduced to silver nanoparticles. The surface color depth value K / S, reflectance transmittance R / T, and UV protection factor (UPF) of the silk were measured. The surface color depth value K / S is shown below. Figure 13 Reflectance transmittance R / T such as Figure 14 The values ​​of L*, a*, and b* are shown in Table 10, and the UV resistance coefficient UPF values ​​are shown in Table 11. Figure 13 The K / S value of silk before and after treatment with PU / dopamine / microcrystals / Ag ions under alkaline conditions. Figure 14 The R / T value is the value of silk before and after treatment with PU / dopamine / microcrystals / Ag ions under alkaline conditions.

[0086] Table 10. L*, a*, and b* values ​​of silk before and after treatment with PU / dopamine / microcrystalline / Ag ions under alkaline conditions.

[0087] Name L＊ a＊ b＊ Original fabric 93.04 3.24 -6.25 WSK / DA+PU+AgNO3+NaOH 62.79 2.04 4.47

[0088] Table 11 UPF values ​​of silk before and after treatment with PU / dopamine / microcrystalline / Ag ions under alkaline conditions

[0089]

[0090]

[0091] Depend on Figure 13It can be seen that the K / S value of silk fabrics treated with polyurethane and silver nitrate in an alkaline environment increases. (From...) Figure 14 It can be seen that the R / T value of silk fabric treated with polyurethane and silver nitrate in an alkaline environment is much smaller than that of untreated silk, indicating that the presence of Ag ions on the fabric surface reduces the fabric's reflectance and transmittance.

[0092] A sample image of silk fabric treated with polyurethane and Ag ions under alkaline conditions is shown below. Figure 15 As shown. Figure 15 Silk fabric treated with PU / dopamine / microcrystalline / Ag ions in an alkaline environment.

[0093] Table 12. Front and back elastic wrinkle recovery angles of silk fabrics treated with PU / dopamine / microcrystalline / Ag ions under alkaline conditions.

[0094] Sample Untreated fabrics PU / WSK / DA+AgNO3 Rapid elastic wrinkle recovery angle (longitude + weft) 184.7° 223.3° Mildly elastic wrinkle recovery angle (warp + weft) 226.4° 288.6°

[0095] As shown in Table 12, under alkaline conditions, the rapid and slow elastic recovery angles of silk treated with polyurethane after adding a colored solution of metal ions significantly increased. Figure 16 The stress-strain curves of silk fabrics before and after treatment with PU / dopamine / microcrystalline / Ag ions in an alkaline environment are shown.

[0096] Table 13 Tensile properties of silk fabrics before and after treatment with PU / dopamine / microcrystalline / Ag ions under alkaline conditions

[0097] Elongation at break (%) Elastic modulus (MPa) Original fabric 31.76 418.54 <![CDATA[PU / WSK / DA+AgNO3]]> 36.13 131.15

[0098] Depend on Figure 16 As shown in Table 13, the strength of silk fabrics treated with colored Ag metal ions added to polyurethane is significantly reduced under alkaline conditions. This is because some fibers of the silk fabric are eroded by alkali after the alkali reduction treatment, resulting in a decrease in the strength of the silk fabric.

[0099] Table 14 Flame retardant properties of silk fabrics before and after treatment with PU / dopamine / microcrystalline / Ag ions under alkaline conditions

[0100] sample Limiting oxygen index (%) Original fabric 23.10 <![CDATA[PU / WSK / DA+AgNO3]]> 31.4

[0101] As shown in Table 14, under alkaline conditions, the limiting oxygen index of silk fabric treated with polyurethane by adding colored Ag metal ion sol is 31.4%, while the limiting oxygen index of untreated silk is 23.10%.

[0102] This invention discovers that chitin microcrystals can promote the polymerization of dopamine on the fiber surface. Combined with polyurethane as a dispersant, this can further effectively promote the reduction and deposition of silver ions on the fabric surface. When silver nitrate is selected as the metal ion solution used, the obtained polyurethane colored film composite silk fabric exhibits good wrinkle resistance, UV resistance, flame retardancy, and strength.

[0103] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. The application of a polyurethane colored film composite functional silk textile in the preparation of antibacterial, anti-UV, and wrinkle-resistant silk textiles, characterized in that: It consists of the following steps, (1) Preparation of chitin microcrystals: Chitin was placed in a light-proof container, sodium periodate solution was added, and the mixture was oxidized by shaking under light-proof conditions. Ethylene glycol was added to react, the mixture was filtered, barium acetate was added, acetone was added, the mixture was allowed to stand, and the precipitate was dried to obtain chitin microcrystals. (2) Preparation of metal ion solutions; (3) Preparation of colored sol: Add the aqueous polyurethane dispersion to water, add the metal ion solution under stirring, add the chitin microcrystals, add dopamine, stir, and obtain colored sol; (4) Preparation of colored sol composite textiles: Immerse the silk fabric in the colored sol prepared in step (3), shake at room temperature, take it out, wash with water, and dry. In step (1), 3g of chitin was placed in a light-proof container, 120ml of 0.3mol / L sodium periodate solution was added, and the mixture was oxidized by vibration at 30°C for 2 hours in the light-proof environment. Then, 20ml of 0.1mol / L ethylene glycol was added and the mixture was reacted for 0.5 hours. The mixture was filtered, 3~5ml of 1.5mmol / L barium acetate was added, and then 120ml of acetone was added. The mixture was allowed to stand for 5 hours, and the precipitate was dried to obtain chitin microcrystals. In step (2), the metal ion solution is a 0.02 mol / L aqueous solution of AgNO3; In step (3), 10 mL of an aqueous polyurethane dispersion with a solid content of 60 wt% is added to 30 mL of water, and 10 mL of the metal ion solution is added under stirring conditions. 0.1 g of the chitin microcrystals are added, followed by 0.1 g of dopamine. The mixture is stirred for 2 hours to obtain a colored sol.

2. Application according to claim 1: In step (4), the room temperature oscillation lasts for 1 hour.

3. The application according to claim 1, characterized in that: In step (1), the sodium periodate solution is an aqueous solution of sodium periodate.

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