Flame-retardant high-elastic composite wool fabric and preparation method thereof

Abstract

The invention discloses a flame-retardant high-elastic composite wool fabric and a preparation method thereof, and belongs to the technical field of composite fabrics, the flame-retardant high-elastic composite wool fabric comprises a flame-retardant layer and a heat insulation layer, the flame-retardant layer and the heat insulation layer are bonded through a PTFE film, the flame-retardant layer is composed of high-flame-retardant wool fibers, and the heat insulation layer is composed of high-barrier polyester fibers; the flame retardant formed through modification of melamine and p-hydroxybenzaldehyde in the wool fibers can release phosphorus-containing free radicals and incombustible gas at high temperature, the generated free radicals act with a high-barrier agent in the polyester fibers to form a more complex chemical network, meanwhile, formation of a carbonized layer is facilitated through gas release, and the flame-retardant effect of the wool fibers is improved. Oxygen and heat transfer is inhibited, flame spreading is further prevented, and the flame-retardant barrier property and the mechanical stability of the wool composite fabric are effectively improved through the chemical crosslinking and synergistic reaction.

Description

Technical Field

[0001] The present invention relates to the technical field of composite fabrics, and in particular to a flame-retardant and highly elastic composite wool fabric and a preparation method thereof. Background Art

[0002] Composite wool fabric is a high-performance fabric made by combining wool with other fiber materials (such as polyester, nylon or spandex) through textile, weaving or knitting processes. It combines the natural comfort, warmth and breathability of wool with the durability, wrinkle resistance and easy care of synthetic fibers. Composite wool fabric is widely used in high-end clothing, sportswear, outdoor equipment and home textiles.

[0003] However, composite wool fabrics excel in comfort and warmth, but have certain drawbacks in tensile strength. Especially when subjected to large stretches or strenuous exercise, the fabric can easily deform or become damaged. Furthermore, due to the presence of tiny pores in the fabric structure, air can penetrate the material, providing the oxygen needed for the flame and accelerating combustion. Therefore, wool fibers have poor flame retardancy. Although wool itself has a certain degree of flame retardancy, the addition of synthetic fibers after composite fabrication may weaken this property, causing performance to deteriorate in high-temperature environments, affecting the overall flame retardancy and further affecting its ability to block air and inhibit combustion.

[0004] Therefore, composite wool blended fabrics face certain challenges in terms of resistance to flammable air barrier, tensile strength, and flame retardancy. In response to the technical defects in this regard, a solution is now proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a flame retardant and highly elastic composite wool fabric and a preparation method thereof, which are used to solve the technical problem in the prior art that the composite wool fabric has to have improved anti-barrier, tensile strength and flame retardancy.

[0006] The object of the present invention can be achieved by the following technical solution: a flame-retardant and highly elastic composite wool fabric, comprising a flame-retardant layer and a heat-insulating layer, wherein the flame-retardant layer and the heat-insulating layer are bonded together by a PTFE film, the flame-retardant layer is composed of highly flame-retardant wool fibers, and the heat-insulating layer is composed of highly barrier polyester fibers;

[0007] The highly flame-retardant wool fiber is obtained by processing the following steps:

[0008] A1. Place 0.30 mol / L diethylamine solution and wool fiber in a ratio of 1-2 g:10-15 mL in a reaction kettle, stir, and keep the temperature at 50-60° C. for 50-60 min to obtain pretreated wool fiber.

[0009] A2. Immersing the pretreated wool fiber in a modified flame retardant and performing a double-dip and double-padding finishing to obtain a highly flame-retardant wool fiber;

[0010] The post-treatment specifically includes: after the reaction is completed, washing with deionized water to neutrality, filtering, placing in a drying oven at 80° C., and drying to constant weight to obtain pretreated wool fibers.

[0011] Furthermore, the modified flame retardant is obtained by processing the following steps:

[0012] B1. Add melamine, p-hydroxybenzaldehyde and N-methylpyrrolidone solution into a reactor at 120-160°C and stir for 2-3 hours, followed by post-treatment to obtain a base powder;

[0013] B2. Add the base powder, N-methylpyrrolidone solvent and ammonium polyphosphate into a reactor and stir for 1-2 hours, and then perform post-processing to obtain a modified flame retardant.

[0014] Furthermore, in step B1, the amount ratio of melamine, p-hydroxybenzaldehyde, and N-methylpyrrolidone solution is 10-15g:8-10g:80-100mL, and the post-treatment includes: after the reaction is completed, raising the temperature of the reactor to 200-210°C, volatilizing the N-methylpyrrolidone solvent, filtering, placing in a vacuum drying oven at 80°C, and drying to constant weight to obtain a base powder. In step B2, the amount ratio of base powder, N-methylpyrrolidone solvent, and ammonium polyphosphate is 2-5g:80-100mL:2-5g, and the post-treatment includes: placing in a vacuum drying oven at 80°C and drying to constant weight to obtain a modified flame retardant.

[0015] The synthetic reaction mechanism of the modified flame retardant is:

[0016] Melamine reacts with p-hydroxybenzaldehyde through a condensation reaction to generate a compound containing an imine bond (-CO-NH-). The generated imine group reacts with the amino group (-NH2) in melamine to form a cross-linked structure of aminoimine. The amino group (-NH2) in melamine can also react with the carboxyl group (-COOH) in p-hydroxybenzaldehyde or ammonium polyphosphate to form an amide bond.

[0017] Furthermore, the two-dipping and two-padding process is obtained by the following steps:

[0018] The pretreated wool fiber and the modified flame retardant are soaked in a padding machine tank at a dosage ratio of 100-200 g:800-1000 mL for 10-20 min, and squeezed through a two-roll mill at a rolling pressure of 400-600 kN, a rolling speed of 100-150 m / min, and a winding speed of 100-280 m / min. The pretreated wool fiber is placed in a heat setting machine for pre-baking at a temperature of 90-110 ° C. for 5-10 min, and a baking temperature of 140-160 ° C. for 5-10 min to obtain a pre-impregnated modified wool fiber;

[0019] The pre-impregnated modified wool fiber and the modified flame retardant are soaked in a padding machine tank at a dosage ratio of 100-200g:800-1000mL for 20-40min, and are squeezed through a two-roller mill with a rolling pressure of 600-800KN, a rolling speed of 150-200m / min, and a winding speed of 200-380m / min. The pre-impregnated wool fiber is placed in a heat setting machine for pre-baking at a pre-baking temperature of 90-110°C for 5-10min, and a baking temperature of 170-190°C for 5-10min to obtain a highly flame-retardant wool fiber.

[0020] Furthermore, the preparation method of the high-barrier polyester fiber is as follows: adding a high-barrier agent and pretreated polyester fiber into a twin-screw extruder, melting and extruding the fibers through the twin-screw extruder, and then spinning the fibers into a spinning machine to prepare the high-barrier polyester fiber;

[0021] The feeding rate of the twin-screw extruder is 8 r / min, the screw speed is 17 r / min; the temperature of the melt spinning machine is 240-250° C., the reaction time is 10-20 min, the stretching temperature is 75-120° C., and the stretching ratio is 70%-90%.

[0022] Furthermore, the method for preparing the pretreated polyester fiber is as follows: polyester fiber and 5wt% polyethylene oxide trialkylammonium chloride aqueous solution are added to a reactor in a dosage ratio of 1g:10-15mL, stirred at a temperature of 30-50°C for 40-60 minutes, and post-processing includes: filtration, washing with deionized water to neutrality, and drying in a vacuum drying oven at a temperature of 70-80°C to constant weight to obtain the pretreated polyester fiber.

[0023] Furthermore, the high barrier agent is obtained by processing the following steps:

[0024] C1, methyl vinyl silicone rubber, dicumyl peroxide, and p-xylene were added to a reaction kettle and stirred for 2-3 hours to obtain a silicone rubber solution;

[0025] C2. Add silicone rubber solution, modified nanographene, waterborne polyurethane and deionized water into an ultrasonic disperser, disperse for 30-40 minutes, and then post-treat to obtain a high barrier agent.

[0026] The synthetic reaction mechanism of high barrier agent is:

[0027] The reactive groups on the side chains of silicone rubber react with the epoxy groups on graphene oxide to form covalent bonds. The hydroxyl groups in silicone rubber can undergo dehydration condensation with silanols generated by hydrolysis of tetraethoxysilane to form Si-O-Si bonds. The amine groups (-NH2-) of silicone rubber react with silanols generated by hydrolysis of tetraethoxysilane to form Si-ON bonds.

[0028] Furthermore, in step D1, the ratio of methyl vinyl silicone rubber, diisopropylbenzene peroxide, and p-xylene is: 10-12 g: 0.1-0.3 g: 100-120 mL; in step D2, the ratio of silicone rubber solution, modified nanographene, water-based polyurethane, and deionized water is: 30-40 mL: 1-3 g: 30-40 mL: 40-45 mL; and the post-treatment includes: after the reaction is completed, placing in a -20°C refrigerator and freezing for 12 hours, freeze-drying, and removing the solvent to obtain a high barrier agent.

[0029] Furthermore, the modified nanographene is obtained by processing the following steps:

[0030] D1. Add graphene oxide, anhydrous ethanol, and distilled water into an ultrasonic disperser and stir for 30-40 minutes to obtain a graphene suspension.

[0031] D2. Add the graphene suspension, ammonia solution and tetraethoxysilane into the reactor, stir for 22-24 hours, and perform post-treatment to obtain modified nanographene.

[0032] The synthetic reaction mechanism of modified nanographene is:

[0033] Tetraethoxysilane undergoes hydrolysis reaction, releasing ethanol and generating silanol (Si-OH) groups, which react with carboxyl, epoxy, and hydroxyl functional groups on the surface of graphene oxide to form covalent bonds (Si-OC), ester bonds, or hydrogen bonds. The silanol groups further undergo condensation reaction to form silicon-oxygen silicon (Si-O-Si). The silane molecules react with the oxygen functional groups of graphene oxide through the Si-O bond to form Si-OC bonds.

[0034] Furthermore, in step D1, the ratio of graphene oxide, anhydrous ethanol, and distilled water is 0.3-0.5 g:80-100 mL:4-6 mL, and the graphene oxide particle size is 1-5 μm. In step D2, the volume ratio of graphene suspension, ammonia solution, and tetraethoxysilane is 90-100 mL:6-8 mL:3-5 mL. The post-treatment includes: filtration, washing with anhydrous ethanol, filtration, and drying the filter cake in a vacuum drying oven at a temperature of 50-60 ° C to constant weight to obtain modified nanographene.

[0035] The present invention also proposes a method for preparing a flame-retardant and highly elastic composite wool fabric, comprising the following steps: sandwiching a PTFE membrane between a flame-retardant layer and a heat-insulating layer and placing it in a hot pressing device, setting the temperature to 200-300°C, the pressure to 1-5MPa, maintaining the pressure for 20-30 minutes, cooling, and curing to obtain a flame-retardant and highly elastic composite wool fabric.

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

[0037] 1. The modified flame retardant added in the present invention promotes the formation of a dense carbonized layer during the combustion process through its rigid molecular chain structure, improves the residual carbon density and void density of the wool fiber, effectively isolates the penetration of oxygen and other flammable gases, and thus inhibits the combustion reaction. At the same time, the modified flame retardant releases phosphorus-containing free radicals and non-combustible gases, which not only occupy the combustion space and inhibit the spread of flames, but also induce the generation of more flame retardants through free radicals, further enhancing the flame retardant effect of the wool fiber. In addition, the imine covalent bond coating formed by the reaction of the modified substance melamine and p-hydroxybenzaldehyde makes the surface of the coated flame retardant smoother, better dispersible in the wool fiber, and improves the water absorption of the wool. Therefore, the coating works synergistically with ammonium polyphosphate to increase the entanglement of the flame retardant and the matrix, effectively inhibiting the thermal decomposition of the wool fiber and reducing the decomposition rate, thereby improving the flame retardant properties and comprehensive properties of the wool fiber.

[0038] 2. Polyester fiber has high elasticity, high toughness and good chemical resistance. The modified barrier agent added to the polyester fiber of the present invention enhances the interaction between molecular chains by introducing epoxy groups and hard segment chains into the side chains of silicone rubber, thereby improving the barrier properties of the silicone rubber matrix. In particular, after the introduction of two-dimensional lamellar graphene oxide modified by tetraethoxysilane, the three-dimensional cross-linked network formed significantly improves the specific surface area and aspect ratio of the barrier agent, making the gas permeation path more tortuous, thereby enhancing the barrier effect of the polyester fiber. At the same time, the epoxy and silane groups in the modifier can chemically react with functional groups such as hydroxyl and ester groups on the surface of the polyester fiber to form strong covalent bonds or physical crosslinks, further improving the interfacial bonding force between the polyester fiber and the silicone rubber matrix, improving the barrier properties of the polyester fiber and enhancing the mechanical properties and heat resistance of the material.

[0039] 3. The modified polyester fiber contains epoxy groups or silane groups. These active groups can react with the hydroxyl and amino groups in the wool fiber, or the nitrogen or phosphorus groups in the flame retardant to form covalent bonds or hydrogen bonds, thereby strengthening the interfacial bonding between the two. The three-dimensional cross-linked structure after graphene oxide modification can form strong physical and chemical connections on the surface of the wool fiber and the surface of the polyester fiber, thereby enhancing the overall structural stability of the composite material. The flame retardant formed by modifying the wool fiber with melamine and p-hydroxybenzaldehyde can release phosphorus-containing free radicals and non-flammable gases at high temperatures. The free radicals generated by these reactions interact with the barrier agent in the polyester fiber to form a more complex chemical network, thereby enhancing the synergistic flame retardant effect of the two fibers. At the same time, the gas release of the flame retardant helps to form a protective carbonized layer, inhibiting the transfer of oxygen and heat, and further preventing the spread of flame. This chemical cross-linking and synergistic reaction effectively improves the flame retardancy, barrier properties and mechanical stability of the wool composite fabric. DETAILED DESCRIPTION

[0040] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0041] Example 1

[0042] This embodiment provides a method for preparing a flame-retardant and highly elastic composite wool fabric, comprising the following steps:

[0043] S1. Preparation of pretreated wool fibers

[0044] Weigh: 100 g of 0.30 mol / L diethylamine solution and 1000 mL of wool fiber are placed in a reactor and stirred at 50°C for 50 minutes. After the reaction is completed, wash with deionized water until neutral, filter, place in an 80°C drying oven, and dry to constant weight to obtain pretreated wool fiber.

[0045] S2. Preparation of base powder

[0046] Weigh: 100 g of melamine, 80 g of p-hydroxybenzaldehyde, and 800 mL of N-methylpyrrolidone solution, add them into a 120°C reactor and stir for 2 hours. After the reaction is completed, raise the temperature of the reactor to 200°C, evaporate the N-methylpyrrolidone solvent, filter, place in a vacuum drying oven at 80°C, and dry to constant weight to obtain the base powder.

[0047] S3. Preparation of modified flame retardant

[0048] Weigh 200 g of base powder, 8000 mL of N-methylpyrrolidone solvent, and 200 g of ammonium polyphosphate, add them into a reactor and stir for 1 hour, place them in a vacuum drying oven at 80° C., and dry them to constant weight to obtain a modified flame retardant.

[0049] S4. Preparation of pretreated polyester fibers

[0050] Weigh: add 100 g of polyester fiber and 1000 mL of 5 wt% polyethylene oxide trialkylammonium chloride aqueous solution into a reactor and stir at 30° C. for 40 minutes. Filter with suction, wash with deionized water until neutral, and dry in a vacuum drying oven at 70° C. to constant weight to obtain pretreated polyester fiber.

[0051] S5. Preparation of silicone rubber solution

[0052] Weigh 1000 g of methyl vinyl silicone rubber, 10 g of dicumyl peroxide, and 10,000 mL of p-xylene, add them into a reactor, and stir for 2 h to obtain a silicone rubber solution.

[0053] S6. Preparation of high barrier agent

[0054] Weigh: add 3000 mL of silicone rubber solution, 100 g of modified nanographene, 3000 mL of waterborne polyurethane, and 4000 mL of deionized water into an ultrasonic disperser and disperse for 30 minutes. After the reaction is completed, place it in a -20°C refrigerator and freeze it for 12 hours. Freeze-dry it and remove the solvent to obtain a high barrier agent.

[0055] S7. Preparation of graphene suspension

[0056] Weigh 30 g of graphene oxide with a particle size of 1-5 μm, 8000 mL of anhydrous ethanol, and 400 mL of distilled water into an ultrasonic disperser and stir for 30 minutes.

[0057] S8. Preparation of modified nanographene

[0058] Weigh: 900 mL of graphene suspension, 60 mL of ammonia solution, and 30 mL of tetraethoxysilane are added to a reactor, stirred for 22 h, filtered, and washed with anhydrous ethanol. After filtering, the filter cake is placed in a vacuum drying oven at 50° C. and dried to constant weight to obtain modified nanographene.

[0059] Example 2

[0060] This embodiment provides a method for preparing a flame-retardant and highly elastic composite wool fabric, comprising the following steps:

[0061] S1. Preparation of pretreated wool fibers

[0062] Weigh: 150 g of 0.30 mol / L diethylamine solution and 1200 mL of wool fiber, put them into a reactor and stir at 55°C for 55 minutes. After the reaction is completed, wash with deionized water until neutral, filter, place in an 80°C drying oven, and dry to constant weight to obtain pretreated wool fiber.

[0063] S2. Preparation of base powder

[0064] Weigh: 120 g of melamine, 90 g of p-hydroxybenzaldehyde, and 900 mL of N-methylpyrrolidone solution, add them into a 130°C reactor and stir for 2.5 hours. After the reaction is completed, raise the temperature of the reactor to 205°C, evaporate the N-methylpyrrolidone solvent, filter, place in a vacuum drying oven at 80°C, and dry to constant weight to obtain the matrix powder.

[0065] S3. Preparation of modified flame retardant

[0066] Weigh 400 g of base powder, 9000 mL of N-methylpyrrolidone solvent, and 400 g of ammonium polyphosphate, add them into a reactor and stir for 1.5 h. Place them in a vacuum drying oven at 80° C. and dry them to constant weight to obtain a modified flame retardant.

[0067] S4. Preparation of pretreated polyester fibers

[0068] Weigh: 100 g of polyester fiber and 1200 mL of 5 wt% polyethylene oxide trialkylammonium chloride aqueous solution are added to a reactor and stirred at 40° C. for 50 min. Filter and wash with deionized water until neutral. Dry in a vacuum drying oven at 75° C. to constant weight to obtain pretreated polyester fiber.

[0069] S5. Preparation of silicone rubber solution

[0070] Weigh 1100 g of methyl vinyl silicone rubber, 20 g of dicumyl peroxide, and 11000 mL of p-xylene, add them into a reactor, and stir for 2.5 h to obtain a silicone rubber solution.

[0071] S6. Preparation of high barrier agent

[0072] Weigh: add 3500 mL of silicone rubber solution, 200 g of modified nanographene, 3500 mL of waterborne polyurethane, and 4200 mL of deionized water into an ultrasonic disperser and disperse for 35 minutes. After the reaction is completed, place it in a -20°C refrigerator and freeze it for 12 hours. Freeze-dry it and remove the solvent to obtain a high barrier agent.

[0073] S7. Preparation of graphene suspension

[0074] Weigh 40 g of graphene oxide with a particle size of 1-5 μm, 9000 mL of anhydrous ethanol, and 500 mL of distilled water into an ultrasonic disperser and stir for 35 minutes.

[0075] S8. Preparation of modified nanographene

[0076] Weigh: 950 mL of graphene suspension, 70 mL of ammonia solution, and 40 mL of tetraethoxysilane are added to a reactor, stirred for 23 h, filtered, and washed with anhydrous ethanol. After filtering, the filter cake is placed in a vacuum drying oven at 55° C. and dried to constant weight to obtain modified nanographene.

[0077] Example 3

[0078] This embodiment provides a method for preparing a flame-retardant and highly elastic composite wool fabric, comprising the following steps:

[0079] S1. Preparation of pretreated wool fibers

[0080] Weigh: 200 g of 0.30 mol / L diethylamine solution and 1500 mL of wool fiber are placed in a reactor and stirred at 60°C for 60 minutes. After the reaction is completed, wash with deionized water until neutral, filter, place in an 80°C drying oven, and dry to constant weight to obtain pretreated wool fiber.

[0081] S2. Preparation of base powder

[0082] Weigh: 150 g of melamine, 100 g of p-hydroxybenzaldehyde, and 1000 mL of N-methylpyrrolidone solution, add them into a 160°C reactor and stir for 3 hours. After the reaction is completed, raise the temperature of the reactor to 2210°C, evaporate the N-methylpyrrolidone solvent, filter, place in a vacuum drying oven at 80°C, and dry to constant weight to obtain the base powder.

[0083] S3. Preparation of modified flame retardant

[0084] Weigh: 500 g of base powder, 10000 mL of N-methylpyrrolidone solvent, and 500 g of ammonium polyphosphate are added to a reactor and stirred for 2 hours. Post-processing includes: placing in a vacuum drying oven at 80° C. and drying to constant weight to obtain a modified flame retardant.

[0085] S4. Preparation of pretreated polyester fibers

[0086] Weigh: 100 g of polyester fiber and 1500 mL of a 5 wt% polyethylene oxide trialkylammonium chloride aqueous solution are added to a reactor and stirred at 50° C. for 60 minutes. Post-treatment includes: filtration, washing with deionized water until neutral, and drying in a vacuum drying oven at 80° C. to constant weight to obtain pretreated polyester fiber.

[0087] S5. Preparation of silicone rubber solution

[0088] Weigh 1200 g of methyl vinyl silicone rubber, 30 g of dicumyl peroxide, and 12000 mL of p-xylene, add them into a reactor, and stir for 3 h to obtain a silicone rubber solution.

[0089] S6. Preparation of high barrier agent

[0090] Weigh: add 4000 mL of silicone rubber solution, 300 g of modified nanographene, 4000 mL of waterborne polyurethane, and 4500 mL of deionized water into an ultrasonic disperser and disperse for 40 minutes. After the reaction is completed, place it in a -20°C refrigerator and freeze it for 12 hours. Freeze-dry it and remove the solvent to obtain a high barrier agent.

[0091] S7. Preparation of graphene suspension

[0092] Weigh 50 g of graphene oxide with a particle size of 1-5 μm, 10,000 mL of anhydrous ethanol, and 600 mL of distilled water into an ultrasonic disperser and disperse and stir for 40 minutes.

[0093] S8. Preparation of modified nanographene

[0094] Weigh: 1000 mL of graphene suspension, 80 mL of ammonia solution, and 50 mL of tetraethoxysilane are added to a reactor, stirred for 24 hours, filtered, and washed with anhydrous ethanol. After filtering, the filter cake is placed in a vacuum drying oven at 60°C and dried to constant weight to obtain modified nanographene.

[0095] Comparative Example 1

[0096] The difference between this comparative example and Example 3 is that in step S1, the polyester fiber is not pretreated.

[0097] Comparative Example 2

[0098] The difference between this comparative example and Example 3 is that in step S3, no modified flame retardant is added.

[0099] Comparative Example 3

[0100] The difference between this comparative example and Example 3 is that in step S6, no high barrier agent is added.

[0101] Performance testing:

[0102] The flame retardant properties of the samples were measured with reference to the standard FZ / T152022-2012 "Flame Retardant Polyester Staple Fiber";

[0103] The gas barrier properties of the sample were measured with reference to the standard GB / T5453-1997 “Determination of Air Permeability of Textile Fabrics”;

[0104] With reference to the first part of the standard GB / T3923.1-2013 "Tensile Properties of Textile Fabrics", the breaking strength and elongation of the fabric were tested. The fabric size was 100.0mm×25.0mm, the tensile test speed was 100mm / min, and each group of tests was averaged over 6-8 times. The specific test results are shown in Table 1:

[0105] Table 1-Performance test data of the sample

[0106]

[0107]

[0108] Data Analysis:

[0109] It can be seen from the relevant data in Table 1 that, compared with the comparative example, the flame retardant and highly elastic composite wool fabric provided by the present invention, the wool composite fabric obtained by adding a modified barrier agent to the polyester fiber and adding the modified flame retardant to the wool fiber and hot pressing with a PTFE membrane can also significantly improve the flame retardancy, tensile strength and barrier properties of the fabric. This allows the fabric to maintain its good functionality and comfort during long-term use in a high temperature and fire environment.

[0110] Compared with Examples 1-3, the breaking strength and breaking tensile properties of Comparative Example 1 are reduced, indicating that after the fiber is immersed in cationic quaternary ammonium salt, the hydrophilicity of the fiber surface is enhanced, which can improve the adsorption of the high-resistance agent and enhance the mechanical properties of the fiber material such as tensile strength.

[0111] Compared with Examples 1-3, the oxygen index of the fabric in Comparative Example 2 decreases significantly, indicating that the epoxy and silane groups in the barrier agent can chemically react with functional groups such as hydroxyl and ester groups on the surface of the polyester fiber to form strong covalent bonds or physical crosslinks, further improving the interfacial bonding strength between the polyester fiber and the silicone rubber matrix, and improving the barrier properties of the composite fiber.

[0112] Compared with Examples 1-3, the air permeability of Comparative Example 3 is reduced, indicating that the modified flame retardant promotes the formation of a dense carbonized layer during the combustion process through its rigid molecular chain structure, improves the residual carbon density and void density of the composite wool fiber, and effectively isolates the penetration of oxygen and other flammable gases.

[0113] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A flame retardant and highly elastic composite wool fabric, comprising a flame retardant layer and a heat insulating layer, characterized in that: The flame retardant layer and the heat insulation layer are bonded by a PTFE film, the flame retardant layer is composed of high flame retardant wool fiber, and the heat insulation layer is composed of high barrier polyester fiber; The highly flame-retardant wool fiber is obtained by processing the following steps: A1. Place 0.30 mol / L diethylamine solution and wool fiber in a reaction kettle according to the amount ratio, stir, and keep the temperature at 50-60°C for 50-60 minutes to obtain pretreated wool fiber; A2. Immerse the pretreated wool fiber in a modified flame retardant and perform double dipping and double padding to obtain highly flame retardant wool fiber.

2. The flame-retardant and highly elastic composite wool fabric according to claim 1, characterized in that: The modified flame retardant is obtained by processing the following steps: B1. Add melamine, p-hydroxybenzaldehyde and N-methylpyrrolidone solution into a reactor at 120-160°C and stir for 2-3 hours, followed by post-treatment to obtain a base powder; B2. Add the base powder, N-methylpyrrolidone solvent and ammonium polyphosphate into a reactor and stir for 1-2 hours, and then perform post-processing to obtain a modified flame retardant.

3. The flame retardant and highly elastic composite wool fabric according to claim 1, characterized in that: The preparation method of the high-barrier polyester fiber comprises the following steps: adding a high-barrier agent and pretreated polyester fiber into a twin-screw extruder, melting and extruding the fibers through the twin-screw extruder, and then spinning the fibers into a spinning machine to prepare the high-barrier polyester fiber.

4. The flame-retardant and highly elastic composite wool fabric according to claim 3, characterized in that: The method for preparing the pretreated polyester fiber comprises the following steps: adding polyester fiber and 5 wt% polyethylene oxide trialkylammonium chloride aqueous solution into a reaction kettle and stirring at a temperature of 30-50° C. for 40-60 minutes, and performing post-treatment to obtain the pretreated polyester fiber.

5. The flame-retardant and highly elastic composite wool fabric according to claim 4, characterized in that: The high barrier agent is obtained by processing the following steps: C1, methyl vinyl silicone rubber, dicumyl peroxide, and p-xylene were added to a reaction kettle and stirred for 2-3 hours to obtain a silicone rubber solution; C2. Add silicone rubber solution, modified nanographene, waterborne polyurethane and deionized water into an ultrasonic disperser, disperse for 30-40 minutes, and then post-treat to obtain a high barrier agent.

6. The flame-retardant and highly elastic composite wool fabric according to claim 5, characterized in that: In step C1, the methyl vinyl silicone rubber, dicumyl peroxide, and p-xylene are used in a ratio of 10-12 g: 0.1-0.3 g: 100-120 mL. In step C2, the silicone rubber solution, modified nanographene, water-based polyurethane, and deionized water are used in a ratio of 30-40 mL: 1-3 g: 30-40 mL: 40-45 mL. Post-processing is performed to obtain a high barrier agent.

7. The flame-retardant and highly elastic composite wool fabric according to claim 6, characterized in that: The modified nano-graphene is obtained by processing the following steps: D1. Add graphene oxide, anhydrous ethanol, and distilled water into an ultrasonic disperser and stir for 30-40 minutes to obtain a graphene suspension. D2. Add the graphene suspension, ammonia solution and tetraethoxysilane into the reactor, stir for 22-24 hours, and perform post-treatment to obtain modified nanographene.

8. The flame-retardant and highly elastic composite wool fabric according to claim 7, characterized in that: In step D1, the amount ratio of graphene oxide, anhydrous ethanol, and distilled water is 0.3-0.5 g:80-100 mL:4-6 mL, and the graphene oxide particle size is 1-5 μm. In step D2, the volume ratio of the graphene suspension, ammonia solution, and tetraethoxysilane is 90-100 mL:6-8 mL:3-5 mL, and post-treatment is performed to obtain modified nanographene.

9. A method for preparing the flame-retardant and highly elastic composite wool fabric according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: sandwiching a PTFE film between a flame retardant layer and a heat insulation layer and placing the film in a hot pressing device, setting the temperature to 200-300°C, the pressure to 1-5 MPa, maintaining the pressure for 20-30 minutes, cooling, and curing to obtain a flame retardant and highly elastic composite wool fabric.

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