A multifunctional fabric and its preparation method

Abstract

This invention relates to a multifunctional fabric and its preparation method. The yarn used in the multifunctional fabric comprises a product obtained by heat treatment of a mixture of shear-stiffening gel (SSG), polyurethane powder (TPU), and flame-retardant nanoparticles. The method includes the following steps: uniformly mixing the shear-stiffening gel and polyurethane powder; adding modified flame-retardant nanoparticles (encapsulated ammonium polyphosphate) to the mixture and kneading it using an open mixing mill; extruding the mixture using a screw extruder at 150 degrees Celsius to obtain a flame-retardant and impact-resistant yarn. The multifunctional fabric is then woven from this yarn. This multifunctional fabric possesses thermodynamic protection and flame-retardant properties and can be widely applied to various parts of the human body, providing thermodynamic protection and flame retardancy, protecting users from impact, temperature, and flame damage.

Description

Technical Field

[0001] This invention belongs to the field of multifunctional fabric technology, specifically relating to a multifunctional fabric and its preparation method. The fabric is a multifunctional fabric with flame retardant, heat insulation and impact resistance properties, and its preparation method. Background Technology

[0002] Fabrics permeate people's daily lives, adding color to the clothing industry and becoming an indispensable part of garment production. As times change and people's living standards improve, the market's demands for clothing are also increasing.

[0003] Elastic fabrics can be adjusted to fit different environments, making them convenient and quick to use. Chinese patent CN209243319U discloses a tubular perforated fabric with a cord-threading function. This fabric has good resilience, can twist and stretch freely in 360 degrees, and will not feel tight or constricting when worn. Furthermore, the cord-threading section and the perforated section are wrinkle-free, mark-free, smooth, and flat.

[0004] Furthermore, fabrics, acting as a barrier between the skin and the external environment, should provide real-time protection. Chinese Patent CN105452552 B discloses a fabric with excellent thermal stability. The DSC endothermic curve of this fabric shows that, compared to the highest melting endothermic temperature of the fabric's constituent yarns, the ratio of heat absorbed on the high-temperature side to the total heat absorbed exceeds 45%. Additionally, the viscoelastic peak temperature (tanδ) of the fabric's constituent yarns is above 115 degrees Celsius, indicating that this fabric can be used in high-temperature environments and provides protection for the human body. Chinese Patent CN106273742 A discloses a breathable fabric with excellent thermal insulation properties. This fabric avoids sticking to the skin, has good breathability, and excellent thermal insulation.

[0005] Based on currently available patents, there is still a lack of research on elastic fabrics that provide both thermal and mechanical protection. Fabrics with only one function, such as thermal insulation or excellent mechanical properties, are difficult to meet the application requirements in practical fields of impact resistance and high-temperature flame retardancy. Moreover, they are expensive, have complex manufacturing processes, and are not convenient for large-scale production and application. Summary of the Invention

[0006] This invention addresses the shortcomings of traditional technologies by providing a fabric with impact resistance and flame retardant properties, as well as its preparation method. The fabric is woven from multifunctional flexible composite yarns possessing excellent flame retardant and mechanical protective properties. This invention expands the application range of the fabric, enabling its use within both mechanical protection and flame retardant ranges. Furthermore, the preparation process of this multifunctional material is simple, and it exhibits good stability over extended periods. Therefore, this fabric shows significant potential in mechanical protection and flame retardancy.

[0007] Specifically, the present invention is achieved through the following technical solution:

[0008] In one embodiment of the present invention, a multifunctional fabric is provided, the multifunctional fabric being a fabric with impact resistance, flame retardancy, and heat insulation properties, wherein the fabric with impact resistance, flame retardancy, and heat insulation properties is woven from composite yarns. The composite yarns are obtained by heat-treating and extruding a mixture comprising shear-hardening adhesive, encapsulated flame-retardant nanoparticles, and thermoplastic powder using a screw extruder.

[0009] In one embodiment of the present invention, the multifunctional fabric is obtained from composite yarns through a special weaving method; preferably, the weaving method is rib weave.

[0010] In one embodiment of the present invention, the composite wire wherein the shear-hardening adhesive is a product obtained by polymerizing hydroxyl silicone oil, boric acid, and octanoic acid at a temperature of 100 to 300 degrees Celsius (e.g., 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, or 300°C).

[0011] In one embodiment of the invention, the shear-hardening adhesive wherein the mass ratio of the hydroxyl silicone oil to boric acid is 60:1 to 10:1 (e.g., the mass ratio of the hydroxyl silicone oil to boric acid is 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, or 10); and the mass ratio of the boric acid to octanoic acid is 600:1 to 300:1 (e.g., the mass ratio of the boric acid to octanoic acid is 600, 500, 400, or 300).

[0012] In one embodiment of the present invention, the thermoplastic powder is a polyurethane powder.

[0013] In one embodiment of the present invention, the mass ratio of the shear-hardening adhesive to the encapsulated flame-retardant nanoparticles is 300:1 to 1:10; for example, the mass ratio of the shear-hardening adhesive to the encapsulated flame-retardant nanoparticles is 300:1, 290:1, 250:1, 200:1, 150:1, 100:1, 90:1, 80:1, 70:1, 60:1, 50:1, 40:1, 30:1, 20:1, 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:1, 0.9:1, 0.8:1, 0.7:1, 0.6:1, 0.5:1, 0.4:1, 0.3:1, 0.2:1, or 0.1:1.

[0014] Preferably, the mass ratio of the shear-hardening adhesive matrix to the encapsulated flame-retardant nanoparticles is 250:1 to 1:8; more preferably, the mass ratio of the shear-hardening adhesive matrix to the encapsulated flame-retardant nanoparticles is 200:1 to 2:7; and even more preferably, the mass ratio of the shear-hardening adhesive matrix to the encapsulated flame-retardant nanoparticles is 150:1 to 3:7.

[0015] In one embodiment of the invention, the mass ratio of the shear-hardening adhesive to the polyurethane powder is 30:1 to 1:20. For example, the mass ratio of the shear-hardening adhesive to the polyurethane powder is 30:1, 25:1, 20:1, 15:1, 10:1, 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:15, 1:17, 1:19, or 1:20.

[0016] In one embodiment of the present invention, the encapsulated flame-retardant nanoparticles are selected from inorganic nanoparticles containing N or P elements; preferably, the encapsulated flame-retardant nanoparticles are encapsulated ammonium polyphosphate nanoparticles.

[0017] In one embodiment of the invention, the heat treatment is performed at a temperature of 30 to 300 degrees Celsius; preferably, the heat treatment is performed at a temperature of 40 to 250 degrees Celsius; more preferably, the heat treatment is performed at a temperature of 60 to 220 degrees Celsius; and most preferably, the heat treatment is performed at a temperature of 110 to 205 degrees Celsius. For example, the heat treatment is performed at temperatures of 110 degrees Celsius, 120 degrees Celsius, 130 degrees Celsius, 140 degrees Celsius, 150 degrees Celsius, 160 degrees Celsius, 170 degrees Celsius, 180 degrees Celsius, 190 degrees Celsius, 200 degrees Celsius, or 205 degrees Celsius.

[0018] In another aspect of the present invention, a method for preparing a multifunctional fabric is provided, the method comprising the following steps:

[0019] a. Mix shear-hardening adhesive, encapsulated flame-retardant nanoparticles, and polyurethane powder evenly;

[0020] b. Then, use an open rubber mixing mill to mix at room temperature for 10 minutes to 1 hour;

[0021] c. The mixture obtained in step b is heat-treated and extruded using a screw extruder at a temperature of 80 to 180 degrees Celsius to obtain composite wire;

[0022] d. After obtaining the composite yarn, a multifunctional fabric is obtained by weaving.

[0023] Furthermore, in step a, shear-hardening adhesive, encapsulated flame-retardant nanoparticles, and polyurethane powder are used.

[0024] Further, in step a, the shear-hardening adhesive is prepared by: (1) mixing boric acid and hydroxyl silicone oil evenly; (2) polymerizing the mixture obtained in step (1) at a temperature of 100 to 300 degrees Celsius for 2 to 18 hours; (3) adding n-octanoic acid dropwise to the product of step (2), followed by reaction for 0.5 to 2 hours. Cooling yields the desired shear-hardening adhesive.

[0025] Furthermore, in step a, the encapsulated flame-retardant particles are prepared by the following steps:

[0026] (1) Ammonium polyphosphate and N,N-dimethylformamide are reacted at 50-100 degrees Celsius for 10-60 minutes; preferably, the ratio of ammonium polyphosphate to N,N-dimethylformamide is 50-70g:150-200ml (for example, the ratio of ammonium polyphosphate to N,N-dimethylformamide is 50g:150-200ml, 55g:150-200ml, 60g:150-200ml, 65g:150-200ml, 70g:150-200ml or 60g:180ml);

[0027] (2) Mix methyl methacrylate and 2-hydroxyethyl acrylate evenly and add the mixture to the product in (1); preferably, the volume ratio of methyl methacrylate to 2-hydroxyethyl acrylate is 4 to 8: 2 to 5 (for example, the volume ratio of methyl methacrylate to 2-hydroxyethyl acrylate is 4: 2 to 5, 4.5: 2 to 5, 5: 2 to 5, 5.5: 2 to 5, 6: 2 to 5, 6.5: 2 to 5, 7: 2 to 5, 7.5: 2 to 5, 8: 2 to 5 or 9: 5);

[0028] (3) Benzoyl peroxide is dissolved in acetone; preferably, the ratio of benzoyl peroxide to acetone is 0.01-0.2g:10-20ml (for example, the ratio of benzoyl peroxide to acetone is 0.01g:10-20ml, 0.03g:10-20ml, 0.08g:10-20ml, 0.1g:10-20ml, 0.15g:10-20ml, 0.12g:10-20ml or 0.2g:10-20ml);

[0029] (4) Adjust the reaction temperature to 50-80 degrees Celsius, and then pour the product from (3) into the product from (2). After reacting for 6-16 hours, wait for the product to cool, then centrifuge and filter it. Dry it under vacuum at 60-100 degrees Celsius for 20-38 hours to obtain encapsulated ammonium polyphosphate flame-retardant particles. Further, the ratio of ammonium polyphosphate in step (1) to methyl methacrylate in step (2) is 50-70g: 4-8ml. For example, the ratio of ammonium polyphosphate in step (1) to methyl methacrylate in step (2) is 50g: 4-8ml, 55g: 4-8ml, 60g: 4-8ml, 65g: 4-8ml, 70g: 4-8ml, or 60g: 6.3ml.

[0030] Further, the mass ratio of ammonium polyphosphate in step (1) to benzoyl peroxide in step (3) is 50:0.01-0.2, 55:0.01-0.2, 60:0.01-0.2, 65:0.01-0.2, 70:0.01-0.2 or 60:0.12.

[0031] Further, in step a, the encapsulated flame-retardant particles are prepared through the following steps:

[0032] (1) 60 g of ammonium polyphosphate and 180 mL of N,N-dimethylformamide were reacted at 50 degrees Celsius for 10 minutes;

[0033] (2) Mix 6.3 mL of methyl methacrylate and 3.5 mL of 2-hydroxyethyl acrylate evenly and add the mixture to the product in (1);

[0034] (3) 0.12 g of benzoyl peroxide was dissolved in 20 mL of acetone;

[0035] (4) Adjust the reaction temperature to 60 degrees Celsius, and then pour the product from (3) into the product from (2). After reacting for 8 hours, wait for the product to cool, then centrifuge and filter it. Dry it under vacuum at 80 degrees Celsius for 24 hours to obtain encapsulated ammonium polyphosphate flame retardant particles.

[0036] The present invention has the following beneficial effects:

[0037] The multifunctional fabric of this invention has thermodynamic protection and flame retardant properties, and can be widely used on various parts of the human body to provide thermodynamic protection and flame retardant functions, protecting users from impact, temperature and flame damage. Attached Figure Description

[0038] Figure 1 This is a drawing of the wire being stretched.

[0039] Figure 2 A comparison of the natural creep of shear-hardened adhesive and wire.

[0040] Figure 3 The impact force dissipation diagram shows the impact force of composite materials with different polyurethane contents under drop hammer impact loading.

[0041] Figure 4 This is a graph showing the results of a vertical combustion test on the composite material.

[0042] Figure 5 This is a graph of cone calorimeter data for composite materials.

[0043] Figure 6 This is a graph showing the thermogravimetric data of the composite material.

[0044] Figure 7 This is a comparison chart showing the impact resistance of modified flame retardants on shear-hardened rubber / polyurethane composites.

[0045] Figure 8 This is a diagram showing the tensile properties of the wire.

[0046] Figure 9 A picture of a fabric woven from yarn.

[0047] Figure 10 This is a diagram showing the impact resistance of the fabric.

[0048] Figure 11 This is a schematic diagram of a weaving mold.

[0049] Figure 12 This diagram illustrates how the weave holes affect the impact resistance of a fabric.

[0050] Figure 13 This is a graph showing the impact resistance of the fabric after washing.

[0051] Figure 14 This is a graph showing the temperature resistance of the fabric.

[0052] Figure 15 This diagram illustrates how the weave holes affect the thermal insulation performance of a fabric.

[0053] Figure 16 This is a diagram showing the application of fabric. Detailed Implementation

[0054] The performance parameters of the samples prepared in the following examples were tested according to the following test methods:

[0055] A. The specific method for measuring the tensile properties of composite wires is as follows:

[0056] The tensile properties of the samples were characterized using a commercial mechanical property testing instrument (MTS Criterion™ Model 43).

[0057] B. The specific method for measuring the flame retardancy level of a sample is as follows:

[0058] Vertical combustion tests were conducted using a CFZ-2 instrument (Jiangning Analytical Instruments Co., Ltd.). A flame approximately two centimeters high was used to burn a sample vertically clamped in a sealed box. The sample dimensions were 130 mm × 13 mm × 3 mm. A stopwatch was used to time the combustion for 10 seconds. Afterward, the flame was removed, and the flame extinguishing time was recorded. This process was repeated twice. The flammability level of the sample was determined based on the sum of the two flame extinguishing times.

[0059] C. The specific method for measuring the heat release performance of the sample is as follows:

[0060] A 100 mm × 100 mm × 3 mm sample was placed in a cone calorimeter (provided by Suzhou Yangyi Wolchi Testing Technology Co., Ltd.) for combustion, with a heat transfer rate of 35 kW per square meter. The combustion environment of the cone calorimeter is extremely similar to that of a real combustion environment, and its test results show a good correlation with the results of large-scale combustion tests, thus characterizing the combustion performance of materials.

[0061] D. The specific methods for measuring the impact resistance of shear-hardening adhesive / polyurethane composite samples and woven fabrics are as follows:

[0062] The drop hammer impact testing system used includes an electrically driven drop hammer (Meters Industrial, ZCJ1302-A), a force sensor (Yangzhou Kedong, KD3005C), a digital oscilloscope (Tektronix DPO 2014B), and a charge amplifier (Donghua Testing, YE5853). Similar to a cylindrical drop hammer, it is released from different heights to apply impact force. A force sensor is placed under the sample and connected in series with the charge amplifier and digital oscilloscope. By recording the impact force experienced by the sample from below, the sample's force dissipation capability and impact resistance are measured.

[0063] E. The specific method for measuring the thermal stability of the sample is as follows:

[0064] The thermal stability of the samples was measured using a thermogravimetric analyzer (TGA Q5000IR, TA, USA) at a heating rate of 10 degrees Celsius per minute, with the heating range from room temperature to 800 degrees Celsius.

[0065] Example 1:

[0066] The preparation method of shear-hardening adhesive is as follows:

[0067] Take the following raw materials in the following mass ratio:

[0068] Hydroxysilicone oil:boric acid = 30:1

[0069] Add 25 microliters of octanoic acid to every 100 grams of hydroxyl silicone oil;

[0070] The preparation steps of shear-hardening adhesive are as follows:

[0071] (1) Add hydroxyl silicone oil and boric acid in a mass ratio of 30:1 to a beaker, and then heat it in an oven at 180 degrees Celsius.

[0072] (2) Add octanoic acid dropwise to the product obtained in (1), and then continue heating for half an hour;

[0073] (3) The above mixture can be cooled to room temperature to obtain the desired shear hardening adhesive.

[0074] Wherein: the boric acid and octanoic acid are produced by Sinopharm Chemical Reagent Co., Ltd., and are of analytical grade; the silicone oil is purchased from Guangzhou Gongwang New Material Technology Co., Ltd., and has a viscosity of 50 to 120 centipoise at 25 degrees Celsius and a hydroxyl content of ≥2.5%.

[0075] Example 2:

[0076] The preparation method of the composite material of shear-hardening adhesive and polyurethane is as follows:

[0077] Take the following raw materials in the following mass ratio:

[0078] The shear-hardening adhesive is the shear-hardening adhesive prepared in Example 1.

[0079] Shear-hardening adhesive: polyurethane = 1:3

[0080] The preparation steps are as follows:

[0081] (4) Mix the shear hardening rubber and polyurethane, and mix them at room temperature using an open mixing mill for 10 minutes.

[0082] (5) Place the mixture from step (4) into an automatic flat vulcanizing apparatus and heat treat it at 150 degrees Celsius for 10 minutes.

[0083] (6) After the mixture has been treated above has cooled to room temperature, it is shaped and collected.

[0084] The polyurethane mentioned above is produced by Fengtai Plastics Co., Ltd., and has a melting point of 90 to 100 degrees Celsius (the same applies to the polyurethane in the following examples).

[0085] Example 3:

[0086] The preparation method of the composite material of shear-hardening adhesive and polyurethane is as follows:

[0087] Take the following raw materials in the following mass ratio:

[0088] Shear-hardening adhesive: polyurethane = 1:4

[0089] The rest is the same as in Example 2.

[0090] Example 4:

[0091] The preparation method of the composite material of shear-hardening adhesive and polyurethane is as follows:

[0092] Take the following raw materials in the following mass ratio:

[0093] Shear-hardening adhesive: Polyurethane = 1:5

[0094] The rest is the same as in Example 2.

[0095] Example 5:

[0096] The preparation method of the composite material of shear-hardening adhesive and polyurethane is as follows:

[0097] Take the following raw materials in the following mass ratio:

[0098] Shear-hardening adhesive: polyurethane = 1:6

[0099] The rest is the same as in Example 2.

[0100] Example 6:

[0101] The preparation method of the composite material of shear-hardening adhesive and polyurethane is as follows:

[0102] Take the following raw materials in the following mass ratio:

[0103] Shear-hardening adhesive: polyurethane = 1:7

[0104] The rest is the same as in Example 2.

[0105] Example 7:

[0106] The preparation method of modified flame-retardant particles is as follows:

[0107] (7) 60 g of ammonium polyphosphate and 180 mL of N,N-dimethylformamide were reacted at 50 degrees Celsius for 10 minutes;

[0108] (8) Mix 6.3 mL of methyl methacrylate and 3.5 mL of 2-hydroxyethyl acrylate evenly and add the mixture to the product in (7);

[0109] (9) 0.12 g of benzoyl peroxide was dissolved in 20 mL of acetone;

[0110] (10) Adjust the reaction temperature to 60 degrees Celsius, and then pour the product from (9) into the product from (8). After reacting for 8 hours, wait for the product to cool and then centrifuge and filter it. Dry it under vacuum at 80 degrees Celsius for 24 hours to obtain encapsulated ammonium polyphosphate flame retardant particles.

[0111] Wherein: benzoyl peroxide, acetone and N,N-dimethylformamide are produced by Sinopharm Chemical Reagent Co., Ltd.; methyl methacrylate, 2-hydroxyethyl acrylate and ammonium polyphosphate are purchased from Aladdin Reagent Co., Ltd.

[0112] Example 8:

[0113] The preparation method of the flame-retardant composite material containing 20 wt% ammonium polyphosphate is as follows:

[0114] Take the following raw materials in the following mass ratio:

[0115] Shear-hardening adhesive: polyurethane = 1:6

[0116] Ammonium polyphosphate accounts for 20 wt% of the total mass of the raw materials (the raw materials consist of shear hardening adhesive (the shear hardening adhesive prepared in Example 1), polyurethane and ammonium polyphosphate);

[0117] (11) Mix shear hardening rubber, flame retardant particles and polyurethane, and mix them at room temperature using an open mixing mill for 10 minutes.

[0118] (12) Place the mixture from step (12) into an automatic flat vulcanizing apparatus and heat treat it at 150 degrees Celsius for 10 minutes;

[0119] (13) After the mixture has been treated above has cooled to room temperature, it is shaped and collected.

[0120] Example 9:

[0121] The preparation method of the flame-retardant composite material containing 25 wt% ammonium polyphosphate is as follows:

[0122] Take the following raw materials in the following mass ratio:

[0123] Shear-hardening adhesive: polyurethane = 1:6

[0124] Ammonium polyphosphate accounts for 25 wt% of the total raw material mass. The raw material consists of shear-hardening adhesive, polyurethane, and ammonium polyphosphate.

[0125] The rest is the same as in Example 8.

[0126] Example 10:

[0127] The preparation method of the flame-retardant composite material containing 20 wt% encapsulated ammonium polyphosphate is as follows:

[0128] Take the following raw materials in the following mass ratio:

[0129] Shear-hardening adhesive: polyurethane = 1:6

[0130] Encapsulated ammonium polyphosphate (prepared in Example 7) accounts for 20 wt% of the total mass of the raw materials, which consist of shear-hardening adhesive, polyurethane and encapsulated ammonium polyphosphate.

[0131] The rest is the same as in Example 8.

[0132] Example 11:

[0133] The preparation method of the flame-retardant composite material containing 25 wt% encapsulated ammonium polyphosphate is as follows:

[0134] Take the following raw materials in the following mass ratio:

[0135] Shear-hardening adhesive: polyurethane = 1:6

[0136] Encapsulated ammonium polyphosphate (prepared in Example 7) accounted for 25 wt% of the total mass of the raw materials, which consisted of shear-hardening adhesive, polyurethane, and encapsulated ammonium polyphosphate.

[0137] The rest is the same as in Example 8.

[0138] Example 12:

[0139] The preparation method of flame-retardant composite wire is as follows:

[0140] The shear-hardening adhesive is the shear-hardening adhesive prepared in Example 1.

[0141] Take the following raw materials in the following mass ratio:

[0142] Shear-hardening adhesive: polyurethane = 1:6

[0143] Encapsulated ammonium polyphosphate (prepared in Example 7) accounts for 20% of the total mass of the raw materials, which consist of shear-hardening adhesive, polyurethane and encapsulated ammonium polyphosphate;

[0144] (14) Mix shear-hardening rubber, polyurethane and encapsulated ammonium polyphosphate, and mix them at room temperature using an open mixing mill for 10 minutes.

[0145] (15) The mixture from (14) is put into a screw extruder and extruded at 150 degrees Celsius to obtain flame-retardant composite wire (wire diameter 1.75 mm).

[0146] The impact resistance of the block-shaped (2 cm × 2 cm × 4 mm) composite materials prepared in Examples 1 to 6 under low-speed impact was tested according to the specific method described in section D of the aforementioned test method for measuring the impact resistance of shear-hardening rubber / polyurethane composite samples and woven fabrics. Thermal stability tests were performed on the samples from Examples 7, 8, and 10, according to the specific method described in section E of the aforementioned test method for measuring the thermal stability of the samples. Vertical burning tests were performed on the samples from Examples 9 and 10, according to the specific method described in section B of the aforementioned test method for measuring the flame retardancy level of the samples. Cone calorimeter tests were performed on the samples from Examples 5, 10, and 11, according to the specific method described in section C of the aforementioned test method for measuring the heat release performance of the samples. A tensile test was performed on the wire from Example 12, according to the specific method described in section A of the aforementioned test method for measuring the tensile properties of the composite wire.

[0147] Polyurethane can be mixed with different amounts of shear-hardening adhesive to prepare flexible impact-resistant composite materials. Figure 1 The natural creep of shear-hardening adhesives at room temperature poses a challenge for further applications; however, composite wires prepared by introducing polyurethane and modified flame retardants overcome this deficiency. Figure 2 ).pass Figure 3 It can be seen that the impact resistance of the 4 mm thick composite material increases with the increase of shear-hardening adhesive content. Compared with the base, the sample SSG / TPU (1:6) can dissipate a force of 3.27 kN to 1.39 kN, while pure polyurethane can only dissipate it to 1.94 kN. The introduction of flame retardants further endows the impact-resistant composite material with excellent flame retardant properties. The matrix of pure shear-hardening adhesive and polyurethane mixture is highly flammable and is non-flammable (NR). The composite material with 25% APP by mass fraction achieves the UL 94V-1 flame retardant level, while the composite material with 20% MHAPP by mass fraction achieves the V-0 flame retardant level, indicating that encapsulated ammonium polyphosphate has superior flame retardant properties. Figure 4 As the content of encapsulated ammonium polyphosphate increases, the heat release of the sample gradually decreases. Figure 5 The thermal stability of modified ammonium polyphosphate is higher than that of the original ammonium polyphosphate, and the thermal stability trend of composite materials with introduced flame-retardant particles is consistent with this. Figure 6 It is worth noting that the introduction of modified flame retardants improved the flame retardant properties and thermal stability of the composite material without affecting its excellent impact resistance. Figure 7 The tensile energy of flame-retardant and impact-resistant composite wires increases with increasing strain. Figure 8 Flame-retardant and impact-resistant composite yarns, due to their excellent flexibility and elasticity, can be woven into fabrics using rib knitting. Figure 9Furthermore, the woven fabric possesses excellent impact resistance. Figure 10 The woven fabric is produced using a designed mold, which is quick and convenient, and the size of the fabric's holes can be controlled through the woven mold. Figure 11 The size of the pores in a fabric has little effect on its impact resistance. Figure 12 In addition, the woven fabric is washable and retains excellent impact resistance even after 50 minutes of washing. Figure 13 When the fabric is placed on a 0°C substrate for 500 seconds, its surface temperature reaches approximately 8°C, demonstrating its excellent resistance to low temperatures. Figure 14 The fabric also possesses excellent thermal insulation properties; the smaller the pores, the better the insulation effect. Figure 15 The figures 2.09 mm, 2.39 mm, 2.54 mm, 2.24 mm, and 2.69 mm in the diagram represent the average pore diameters. In summary, this fabric combines flame retardancy, heat insulation, and impact resistance, making it suitable for use on firefighters. Figure 16 ).

[0148] In summary, the preparation method of the multifunctional flexible fabric of the present invention expands the application range of elastic fabrics, enabling them to be used in the fields of mechanical protection and flame retardancy.

[0149] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a multifunctional fabric, characterized in that, The multifunctional fabric is a fabric with impact resistance, flame retardancy and heat insulation properties. The fabric is woven from composite yarns. The composite yarns are obtained by extruding a mixture containing shear-hardening adhesive, encapsulated flame-retardant nanoparticles and thermoplastic powder after heat treatment in a screw extruder. The weaving method is rib weave. The shear-hardening adhesive mentioned above is a product obtained by polymerizing hydroxyl silicone oil, boric acid, and octanoic acid at a temperature of 100 to 300 degrees Celsius. The mass ratio of the hydroxyl silicone oil to boric acid is 55:1 to 10:1; the mass ratio of the boric acid to octanoic acid is 600:1 to 300:1; and the thermoplastic powder is polyurethane powder. The mass ratio of the shear-hardening adhesive to the encapsulated flame-retardant nanoparticles is 250:1 to 1:

8. The mass ratio of the shear-hardening adhesive to the polyurethane powder is 30:1 to 1:20; The encapsulated flame-retardant nanoparticles are encapsulated ammonium polyphosphate; The method includes the following steps: a) Mix shear-hardening adhesive, encapsulated flame-retardant nanoparticles and polyurethane powder evenly; b) Then, use an open rubber mixing mill to mix at room temperature for 10 minutes to 1 hour; c) The mixture obtained in step b is heat-treated and extruded using a screw extruder at a temperature of 80 to 180 degrees Celsius to obtain composite wire; d) After obtaining the composite yarn, a multifunctional fabric is obtained through weaving; In step a, the shear-hardening adhesive is prepared as follows: (1) Mix boric acid and hydroxyl silicone oil evenly; (2) Polymerize the mixture obtained in step (1) at a temperature of 100 to 300 degrees Celsius for 2 to 18 hours; (3) Add octanoic acid dropwise to the product of step (2), then react for 0.5 to 2 hours, cool, and obtain the desired shear-hardening gel; In step a, the encapsulated flame-retardant nanoparticles are prepared through the following steps: (a1) Ammonium polyphosphate and N,N-dimethylformamide are reacted at 50-100 degrees Celsius for 10-60 minutes; the ratio of ammonium polyphosphate to N,N-dimethylformamide is 50-70g: 150-200ml; (a2) Mix methyl methacrylate and 2-hydroxyethyl acrylate evenly and add the mixture to the product in (a1); the volume ratio of methyl methacrylate to 2-hydroxyethyl acrylate is 4~8:2~5; (a3) Benzoyl peroxide is dissolved in acetone; the ratio of benzoyl peroxide to acetone is 0.01~0.2g:10~20ml; (a4) Adjust the reaction temperature to 50-80 degrees Celsius, then pour the product from (a3) ​​into the product from (a2); after reacting for 6-16 hours, wait for the product to cool and then centrifuge and filter it, and vacuum dry it at 60-100 degrees Celsius for 20-38 hours to obtain encapsulated ammonium polyphosphate flame retardant particles; wherein the ratio of ammonium polyphosphate in step (a1) to methyl methacrylate in step (a2) is 50-70g: 4-8ml; the mass ratio of ammonium polyphosphate in step (a1) to benzoyl peroxide in step (a3) ​​is 50-70: 0.01-0.2.

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