Fireproof early warning flame-retardant fabric and preparation method and application thereof

Abstract

The application provides a fireproof early warning flame-retardant fabric, a preparation method and application thereof. The fireproof early warning flame-retardant fabric comprises a fabric substrate, at least one flame-retardant layer and at least one early warning layer coated on the surface of the fabric substrate, wherein the flame-retardant layer comprises a cationic polymer-flame retardant coating unit, the early warning layer comprises a cationic polymer-early warning material coating unit, and the flame retardant and the early warning material are negatively charged. The fabric has low heat release rate and total smoke production, short ignition time, and excellent early warning and heat insulation performance.

Description

Technical Field

[0001] This invention relates to the field of functional materials technology, specifically to a fire-prevention and flame-retardant fabric, its preparation method, and its application. Background Technology

[0002] Textiles, due to their flammable properties, are a significant cause of fires. Traditional fire monitoring sensors typically monitor and issue real-time warnings by tracking changes in humidity, temperature, light intensity, and smoke from burning materials at the fire scene. However, because the fire is often some distance from the sensor, the alarm response time is frequently prolonged. Relying on-site fire warning systems suffers from alarm lag, failing to provide sufficient time for timely fire suppression and evacuation. Therefore, researching novel fire-alert fabrics to shorten the response time of fire warning systems is crucial for achieving early fire detection and reducing the occurrence of fires.

[0003] MXenes are a class of two-dimensional inorganic compounds composed of transition metal carbides, nitrides, or carbonitrides. Their abundant hydroxyl groups and terminal oxygen atoms on the surface give them excellent hydrophilicity. Furthermore, MXenes possess the electrical and thermoelectric properties of metal carbides, generating a stable electromotive force under a certain temperature difference, making them ideal materials for fabric fire warning sensors. When the fabric surface catches fire, a thermoelectric potential is generated, connecting a conductive circuit and triggering the warning system for timely fire alerts. However, the application of MXenes is limited by their relatively low thermoelectric efficiency. Moreover, there are currently few fabric products that combine both flame-retardant and early warning properties. Summary of the Invention

[0004] To address one of the aforementioned technical problems in the prior art, this invention provides a fabric with both flame-retardant and fire warning functions, and a method for preparing the same. This invention utilizes a layer-by-layer self-assembly technique to assemble different numbers of flame retardants and warning materials on the surface of a fabric substrate, leveraging the synergistic effect between the materials to give the fabric excellent fire warning and flame-retardant properties.

[0005] The technical solution of the present invention is as follows:

[0006] In a first aspect, the present invention provides a fire-prevention and flame-retardant fabric, comprising a fabric substrate and at least one flame-retardant layer and at least one warning layer coated on the surface of the fabric substrate, wherein the flame-retardant layer comprises a cationic polymer-flame retardant coating unit, and the warning layer comprises a cationic polymer-warning material coating unit, wherein the flame retardant and the warning material are negatively charged.

[0007] In some embodiments, the cationic polymer includes at least one of polyethyleneimine (PEI), hyperbranched polyethyleneimine (BPEI), chitosan (CH), a silane coupling agent, and starch. The silane coupling agent is preferably a nitrogen-containing silane coupling agent such as γ-aminopropyltriethoxysilane (KH-550), γ-aminopropylmethyldiethoxysilane (KH-902), or γ-aminoethylaminopropyltrimethoxysilane (KH-792).

[0008] In some preferred embodiments, the cationic polymer comprises polyethyleneimine and / or hyperbranched polyethyleneimine.

[0009] In some specific embodiments, the cationic polymer includes polyethyleneimine.

[0010] In some embodiments, the flame retardant comprises a negatively charged phosphorus-based flame retardant, such as phytic acid (PA) and / or ammonium polyphosphate (APP). In some embodiments, the flame retardant comprises a DOPO-type flame retardant, such as [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphoric acid hexane-6-yl)methyl]succinic acid (DDP).

[0011] The early warning materials described in this invention include, but are not limited to, two-dimensional materials such as graphene and MXene. In some embodiments, the early warning material includes MXene. In some embodiments, the MXene is obtained by chemical etching of Ti3AlC2. In some embodiments, the MXene is obtained by chemical etching of Ti3AlC2 using acidic LiF. In some embodiments, the MXene is obtained by chemical ball milling of Ti3AlC2 using acidic LiF. In some embodiments, the preparation method of the MXene includes:

[0012] Ti3AlC2 was mixed with a solution containing hydrochloric acid and LiF and reacted at 25-50℃ for 20-30 h. The solid and liquid phases were separated, and the solid phase was the product MXene.

[0013] In some preferred embodiments, the method for preparing the MXene includes:

[0014] Ti3AlC2 and LiF were first ball-milled together, then mixed with hydrochloric acid solution and reacted at 25-50℃ for 20-30h. The solid and liquid phases were separated, and the solid phase was the product MXene.

[0015] In some embodiments, the number of flame-retardant layers and the number of warning layers are the same. In some embodiments, the number of flame-retardant layers and the number of warning layers are different. In some embodiments, the number of flame-retardant layers is 1 to 10, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 layers, preferably 1 to 5 layers, more preferably 3 to 5 layers. In some embodiments, the number of warning layers is 1 to 10, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 layers, preferably 1 to 5 layers, more preferably 3 to 5 layers.

[0016] In some embodiments, the flame-retardant layer and the warning layer have the same number of layers, and the flame-retardant layer and the warning layer are spaced apart.

[0017] In some preferred embodiments, the surface of the fabric substrate is coated with N flame-retardant layers and N warning layers sequentially from bottom to top, where N is an integer between 1 and 5. In some specific embodiments, the surface of the fabric substrate is coated with one flame-retardant layer and one warning layer sequentially from bottom to top. In some specific embodiments, the surface of the fabric substrate is coated with two flame-retardant layers and two warning layers sequentially from bottom to top. In some specific embodiments, the surface of the fabric substrate is coated with three flame-retardant layers and three warning layers sequentially from bottom to top. In some specific embodiments, the surface of the fabric substrate is coated with four flame-retardant layers and four warning layers sequentially from bottom to top. In some specific embodiments, the surface of the fabric substrate is coated with five flame-retardant layers and five warning layers sequentially from bottom to top.

[0018] In some preferred embodiments, the surface of the fabric substrate is coated with N warning layers and N flame-retardant layers sequentially from bottom to top, where N is an integer between 1 and 5. In some specific embodiments, the surface of the fabric substrate is coated with one warning layer and one flame-retardant layer sequentially from bottom to top. In some specific embodiments, the surface of the fabric substrate is coated with two warning layers and two flame-retardant layers sequentially from bottom to top. In some specific embodiments, the surface of the fabric substrate is coated with three warning layers and three flame-retardant layers sequentially from bottom to top. In some specific embodiments, the surface of the fabric substrate is coated with four warning layers and four flame-retardant layers sequentially from bottom to top. In some specific embodiments, the surface of the fabric substrate is coated with five warning layers and five flame-retardant layers sequentially from bottom to top.

[0019] In some preferred embodiments, the flame-retardant layer comprises 1 to 10 layers, and the warning layer comprises 1 layer, with the warning layer located as the outermost layer on the surface of the fabric substrate. In some preferred embodiments, the surface of the fabric substrate is coated with 1 to 5 flame-retardant layers and 1 warning layer sequentially from bottom to top. In some specific embodiments, the surface of the fabric substrate is coated with 1 flame-retardant layer and 1 warning layer sequentially from bottom to top. In some specific embodiments, the surface of the fabric substrate is coated with 2 flame-retardant layers and 1 warning layer sequentially from bottom to top. In some specific embodiments, the surface of the fabric substrate is coated with 3 flame-retardant layers and 1 warning layer sequentially from bottom to top. In some specific embodiments, the surface of the fabric substrate is coated with 4 flame-retardant layers and 1 warning layer sequentially from bottom to top. In some specific embodiments, the surface of the fabric substrate is coated with 5 flame-retardant layers and 1 warning layer sequentially from bottom to top.

[0020] In some embodiments, the flame-retardant layer includes a polyethyleneimine-phytic acid coating unit and / or a polyethyleneimine-ammonium polyphosphate coating unit, and the warning layer includes a polyethyleneimine-MXene coating unit.

[0021] In some embodiments, the polyethyleneimine coating in the flame-retardant layer is disposed in the innermost layer of the fabric substrate. The innermost layer in this invention refers to the coating that is directly connected to the fabric substrate.

[0022] In some embodiments, the negatively charged warning material layer is disposed on the outermost layer of the fabric substrate.

[0023] In some embodiments, the negatively charged flame-retardant material layer is disposed on the outermost layer of the fabric substrate.

[0024] The fabrics described in this invention include, but are not limited to: polyester fabrics, cotton fabrics, linen fabrics, acrylic fabrics, polypropylene fabrics, polyester fabrics, nylon fabrics, vinylon fabrics, polyester / cotton blended fabrics, viscose fiber fabrics, Lyocell fiber fabrics, etc.

[0025] In some embodiments, the fabric is a modified or unmodified polyester fabric. In some embodiments, the fabric is a polyester fabric modified with a phosphorus-based flame retardant. In some embodiments, the fabric is a polyester fabric modified with 2-carboxyethylphenylphosphine (CEPPA) or [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphazenehexane-6-yl)methyl]succinic acid (DDP).

[0026] In a second aspect, the present invention provides a method for preparing the fire-retardant and flame-retardant fabric described in the first aspect, comprising the following steps:

[0027] (1) The fabric is pretreated with an alkaline substance and then immersed in a solution containing a cationic polymer and dried, or the fabric is immersed in a solution containing a self-polymerizable monomer and a cationic polymer and dried to obtain a fabric coated with a cationic polymer.

[0028] (2) The fabric with the surface coated with cationic polymer obtained in step (1) is immersed in a solution containing the flame retardant or a solution containing the warning material and dried to obtain a fabric with a flame retardant layer or a fabric with a warning layer.

[0029] (3) The fabric obtained in step (2) is immersed in a solution containing a cationic polymer, dried, and then immersed in a solution containing the warning material or a solution containing the flame retardant material. After drying, a fabric with at least one flame retardant layer and at least one warning layer coated on the surface is obtained.

[0030] The method of the present invention adopts layer-by-layer self-assembly technology. By adjusting the immersion sequence and number of times in steps (2) and (3), fabrics with different numbers and arrangements of flame-retardant layers and warning layers can be obtained.

[0031] In some embodiments, in step (1), the alkaline substance includes at least one of alkali metal hydroxides and alkaline earth metal hydroxides, preferably one or more of sodium hydroxide, potassium hydroxide, and calcium hydroxide.

[0032] In some embodiments, in step (1), the concentration of the cationic polymer in the solution containing the cationic polymer is 0.1 wt% to 10 wt%, for example, 0.25 wt%, 0.5 wt%, 0.8 wt%, 1.0 wt%, 2 wt%, 3 wt%, 5 wt%, 8 wt%, 10 wt%, or any value between therewith, preferably 0.25 wt% to 1.0 wt%. In some embodiments, in step (1), the pH of the solution containing the cationic polymer is 9.5 to 10.5.

[0033] In some embodiments, in step (1), the self-polymerizable monomer includes dopamine and / or dopamine analogues. By utilizing the self-polymerization reaction of dopamine or dopamine analogues, and simultaneously crosslinking cationic polymers such as PEI, a modifying coating can be formed on the fabric surface to improve charge strength.

[0034]

[0035] The dopamine-like structure described in this invention is shown in Formula I below:

[0036]

[0037] In Formula I, R1, R2, and R4 may be the same or different, and each is independently selected from halogen, cyano, hydroxyl, carboxyl, branched or straight-chain alkyl with 1 to 10 carbon atoms, cycloalkyl with 3 to 12 carbon atoms, alkoxy with 1 to 10 carbon atoms, aryloxy with 6 to 20 carbon atoms, aryl with 6 to 20 carbon atoms, or heteroaryl with 3 to 20 carbon atoms; R3 is selected from branched or straight-chain alkyl with 1 to 10 carbon atoms, cycloalkyl with 3 to 12 carbon atoms, alkoxy with 1 to 10 carbon atoms, aryloxy with 6 to 20 carbon atoms, aryl with 6 to 20 carbon atoms, or heteroaryl with 3 to 20 carbon atoms.

[0038] In some embodiments, in Formula I above, R1, R2, and R4 may be the same or different, and each is independently selected from halogen, cyano, hydroxyl, carboxyl, branched or straight-chain alkyl having 1 to 6 carbon atoms, cycloalkyl having 3 to 8 carbon atoms, alkoxy having 1 to 6 carbon atoms, aryloxy having 6 to 15 carbon atoms, aryl having 6 to 15 carbon atoms, or heteroaryl having 3 to 15 carbon atoms.

[0039] In some specific embodiments, in Formula I above, R1, R2 and R4 may be the same or different, and each is independently selected from halogen, cyano, hydroxy, carboxyl, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, n-pentyl, n-hexyl, cyclopentyl, cyclohexyl, methoxy, ethoxy, propoxy, phenoxy or phenyl.

[0040] In some embodiments, R3 is selected from branched or straight-chain alkyl groups having 1 to 6 carbon atoms, cycloalkyl groups having 3 to 8 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, aryloxy groups having 6 to 15 carbon atoms, aryl groups having 6 to 15 carbon atoms, or heteroaryl groups having 3 to 15 carbon atoms.

[0041] In some specific embodiments, in Formula I above, R3 is selected from methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, n-pentyl, n-hexyl, cyclopentyl, cyclohexyl, methoxy, ethoxy, propoxy, phenoxy, or phenyl.

[0042] In some embodiments, in step (1), the solution containing the self-polymerizable monomer and the cationic polymer further includes a buffer solution, said buffer solution comprising a tris(hydroxymethyl)aminomethane salt solution system and / or a sodium acetate-acetic acid buffer solution of NaIO4. Preferably, the pH of the tris(hydroxymethyl)aminomethane salt system is 8–9.5. Preferably, the concentration of NaIO4 is 25–35 mM. Preferably, the concentration of the sodium acetate-acetic acid buffer solution is 10–30 mM, and the pH is 4.0–5.5.

[0043] In some embodiments, in step (1), the concentration of the cationic polymer in the solution containing the self-polymerizable monomer and the cationic polymer is 0.1 wt% to 10 wt%, for example, 0.25 wt%, 0.5 wt%, 0.8 wt%, 1.0 wt%, 2 wt%, 3 wt%, 5 wt%, 8 wt%, 10 wt%, or any value between them, preferably 0.5 wt% to 1.5 wt%.

[0044] In some embodiments, in step (1), the concentration of the self-polymerizable monomer in the solution containing the self-polymerizable monomer and the cationic polymer is 1 to 10 g / L, for example 1.2 g / L, 1.5 g / L, 2 g / L, 2.5 g / L, 3 g / L, 5 g / L, 8 g / L, 10 g / L or any value between them, preferably 1.5-2.5 g / L.

[0045] In some embodiments, in step (1), the immersion time in the solution containing the cationic polymer is 2-30 min, for example, 2 min, 5 min, 8 min, 10 min, 15 min, 20 min, 30 min, etc.

[0046] In some embodiments, in step (1), the immersion time in the solution containing the self-polymerizable monomer and the cationic polymer is 30-180 min, for example, it can be 30 min, 45 min, 60 min, 90 min, 120 min, 150 min, 180 min, etc.

[0047] In some embodiments, the drying time is 20-60 minutes, for example, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, etc.

[0048] In some embodiments, step (1) includes: immersing the fabric in a solution containing an alkaline substance for 30-120 minutes, washing and drying, then immersing it in a solution containing a cationic polymer for 2-30 minutes and drying. Preferably, the temperature of the solution containing the alkaline substance is 40-80°C.

[0049] In some embodiments, step (1) includes: immersing the fabric in a mixture containing a cationic polymer, DA·HCl, and the oxidant NaIO4, reacting at 15-50°C for 30-180 min, and drying to obtain a dopamine-modified fabric coated with the cationic polymer. Preferably, the mixture further contains a buffer solution, which includes a sodium acetate-acetic acid buffer solution, preferably with a concentration of 15-25 mM. Preferably, the pH of the mixture is 4.5-5.5.

[0050] In some embodiments, in steps (2) and (3), the concentration of the cationic polymer in the solution containing the cationic polymer is 0.1 wt% to 10 wt%, for example, 0.1 wt%, 0.25 wt%, 0.5 wt%, 0.8 wt%, 1.0 wt%, 3 wt%, 5 wt%, 8 wt%, 10 wt%, or any value between them, preferably 0.25 wt% to 1.0 wt%. In some embodiments, in steps (2) and (3), the pH of the solution containing the cationic polymer is 9.5 to 10.5.

[0051] In some embodiments, in steps (2) and (3), the concentration of the warning material in the solution containing the warning material is 5 to 100 mg / mL, for example, 5 mg / mL, 10 mg / mL, 15 mg / mL, 20 mg / mL, 30 mg / mL, 40 mg / mL, 60 mg / mL, 80 mg / mL, 100 mg / mL or any value between them, preferably 5 to 30 mg / mL, more preferably 5 to 15 mg / mL.

[0052] In some embodiments, in steps (2) and (3), the concentration of the flame retardant in the solution containing the flame retardant is 1 wt% to 20 wt%, for example, 1 wt%, 3 wt%, 5 wt%, 8 wt%, 10 wt%, 15 wt%, 20 wt%, or any value between them, preferably 1 wt% to 5 wt%. In some embodiments, in steps (2) and (3), the pH of the solution containing the flame retardant is 3.5 to 4.5.

[0053] In some implementations, the immersion time in steps (2) and (3) is 2-30 min, for example 2 min, 5 min, 8 min, 10 min, 15 min, 20 min, 25 min, 30 min or any value between them.

[0054] In some embodiments, the method includes:

[0055] (1) The fabric is pretreated with an alkaline substance and then immersed in a solution containing a cationic polymer and dried, or the fabric is immersed in a solution containing a self-polymerizable monomer and a cationic polymer and dried to obtain a fabric coated with a cationic polymer.

[0056] (2) The fabric with the surface coated with the cationic polymer is immersed in a solution containing the flame retardant and dried to obtain a fabric with a flame retardant layer on the surface.

[0057] (3) The fabric with a flame-retardant layer on its surface is immersed in a solution containing a cationic polymer, dried, and then immersed in a solution containing the warning material, and dried to obtain a fabric with a flame-retardant layer and a warning layer on its surface in sequence.

[0058] Optionally, based on the fabric obtained in step (3), steps (2) and (3) are repeated m-1 times to obtain a fabric coated with m flame-retardant layers and m warning layers in sequence, where m ≥ 2, preferably 2 ≤ m ≤ 10.

[0059] In some embodiments, the method includes:

[0060] (1) The fabric is pretreated with an alkaline substance and then immersed in a solution containing a cationic polymer and dried, or the fabric is immersed in a solution containing a self-polymerizable monomer and a cationic polymer and dried to obtain a fabric coated with a cationic polymer.

[0061] (2) The fabric coated with the cationic polymer is immersed in a solution containing the warning material and dried to obtain a fabric coated with one warning layer.

[0062] (3) The fabric with a warning layer coated on the surface is immersed in a solution containing a cationic polymer, dried, and then immersed in a solution containing the flame retardant, and dried to obtain a fabric with a warning layer and a flame retardant layer coated on the surface in sequence.

[0063] Optionally, based on the fabric obtained in step (3), steps (2) and (3) are repeated n-1 times to obtain a fabric with n warning layers and n flame retardant layers sequentially coated on the surface, where n≥2, preferably 2≤n≤10.

[0064] In some embodiments, the method includes:

[0065] (1) The fabric is pretreated with an alkaline substance and then immersed in a solution containing a cationic polymer and dried, or the fabric is immersed in a solution containing a self-polymerizable monomer and a cationic polymer and dried to obtain a fabric coated with a cationic polymer.

[0066] (2) The fabric coated with the cationic polymer is immersed in a solution containing the flame retardant and dried to obtain a fabric with one flame retardant layer on its surface; optionally, the obtained fabric with one flame retardant layer on its surface is immersed in a solution containing the cationic polymer, dried, and then immersed in a solution containing the flame retardant and dried again, and the operation is repeated p-1 times, where p≥1, to obtain a fabric with p flame retardant layers on its surface, preferably, 1≤p≤10; and

[0067] (3) The fabric with p flame-retardant layers on the surface obtained in step (2) is sequentially immersed in a solution containing cationic polymer and a solution containing the warning material to obtain a fabric with p flame-retardant layers and 1 warning layer on the surface.

[0068] Thirdly, the present invention provides the application of the fire-prevention and flame-retardant fabric described in the first aspect in fire warning products and / or flame-retardant products.

[0069] The fire warning products and flame-retardant products described in this invention include, but are not limited to, alarm lights, alarms, fire blankets, fire-resistant and flame-retardant tents, fire-resistant and flame-retardant clothing, etc.

[0070] Compared with the prior art, the present invention has the following beneficial technical effects:

[0071] 1. This application uses positively charged cationic polymers (such as PEI) as flame retardants. Utilizing the electrostatic interaction between positive and negative charges, negatively charged flame retardants and negatively charged warning materials are selected. A flame retardant layer containing cationic polymer-flame retardant coating units and a warning layer containing cationic polymer-warning material coating units are constructed using a layer-by-layer self-assembly technology. This results in a fabric with both flame retardant and warning functions, which can effectively reduce the heat release rate and total smoke production of the original fabric, has a high char residue rate, short ignition time, long warning time, and excellent heat insulation performance.

[0072] 2. The preparation method of this application is simple. After pretreating the polyester fabric with polymerizable monomers such as dopamine and other polymer crosslinking cationic polymers, it can effectively improve the loading capacity and flame retardant efficiency of the LBL assembly layer compared with the traditional alkali pretreatment method. Attached Figure Description

[0073] Figure 1 The images show SEM images of the FR@PM series modified fabrics prepared in Example 1, where (a): FRPET after alkali treatment, (b): FRPET@PEI after alkali treatment, (c): FRPET@PEI / PA after alkali treatment, (d): FR@PM-1, (e): FR@PM-2, and (f): FR@PM-3.

[0074] Figure 2 SEM images of the FPP@PM series modified fabrics prepared in Example 2 and the FPP@AM series modified fabrics prepared in Example 3 are shown, where (a): FPP, (b): FPP@MXene, (c): FPP@PM-1, (d): FPP@PM-2, (e): FPP@PM-3, (f): FPP@AM-1, (g): FPP@AM-2, (h): FPP@AM-3.

[0075] Figure 3The images show SEM images of the FPP@APP series modified fabrics prepared in Example 4, where (a): FPP@APP, (b): FPP@A1-M1, (c): FPP@A3-M1, and (d): FPP@A5-M1.

[0076] Figure 4 TG curves of FRPET fabric, FPP and FPP@PM-3 prepared in Example 2, FPP@AM-3 prepared in Example 3, and FPP@A5-M1 prepared in Example 4 under nitrogen atmosphere.

[0077] Figure 5 The heat release rate curves of the FRPET and FR@PM series modified polyester fabrics prepared in Example 1 are shown.

[0078] Figure 6 The heat release rate curves of the FRPET, FPP and FPP@PM series modified polyester fabrics prepared in Example 2 are shown.

[0079] Figure 7 The graph shows the heat release rate curves of the FRPET and FPP@AM series modified polyester fabrics prepared in Example 3.

[0080] Figure 8 The graph shows the heat release rate curves of the FRPET and FPP@AM series modified polyester fabrics prepared in Example 4.

[0081] Figure 9 The thermoelectric voltage versus temperature difference is a fitting curve of the three modified polyester fabrics prepared in Example 2 (FPP@PM-3), Example 3 (FPP@AM-3), and Example 4 (FPP@A5-M1).

[0082] Figure 10 The alarm time on a flame is shown for three modified polyester fabrics prepared in Example 2 (FPP@PM-3), Example 3 (FPP@AM-3), and Example 4 (FPP@A5-M1) when the trigger threshold value is 0.4mV.

[0083] Figure 11 Thermal infrared images of three modified polyester fabrics—FRPET, FPP@PM-3 prepared in Example 2, FPP@AM-3 prepared in Example 3, and FPP@A5-M1 prepared in Example 4—burned for different times. Detailed Implementation

[0084] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way.

[0085] The term "MXene" used in this article refers to a special class of two-dimensional inorganic compounds, which are two-dimensional materials with surface-active groups obtained by etching the intermediate layer of MAX (M represents a transition metal element, A represents Si or Al, and X represents N or C) through a series of electrochemical or chemical methods.

[0086] The principle behind the term "layer-by-layer self-assembly (LBL)" used in this article is the formation of a stable, structurally complete, and functionally specific thin film on a target substrate through the interaction of functional groups on each assembly unit. The driving force can be intermolecular covalent bonds, hydrogen bonds, or the attraction between positive and negative charges. A common driving force for LBL film formation is the electrostatic interaction between positive and negative charges. When the substrate itself has a charge, it is immersed in an electrolyte solution with the opposite charge. The polyelectrolyte deposits on the surface of the substrate and neutralizes the opposite charge until the neutralized polyelectrolyte film has sufficient electrostatic repulsion with the solution, resulting in a stable deposition layer. At this point, the charge of the polyelectrolyte film deposited on the substrate is opposite to that of the previous layer. Repeated immersion ensures effective self-assembly.

[0087] The reagents used in this article, along with their specifications and sources, are shown in Table 1.

[0088] Table 1

[0089] name English abbreviation Specification factory Anhydrous ethanol <![CDATA[C2H5OH]]> 99.7%, AR Beijing Bailingwei Technology Co., Ltd. lithium fluoride LiF AR Jilin Yiyi Technology Co., Ltd. Aluminum carbide <![CDATA[Ti3AlC2]]> 400 mesh Jilin Yiyi Technology Co., Ltd. hydrochloric acid HCl 36-38％ Modern Oriental Technology Development Co., Ltd. Phytic acid PA 50％ Shanghai Aladdin Biochemical Technology Co., Ltd. Polyethyleneimine PEI MW10000 Shanghai Aladdin Biochemical Technology Co., Ltd. Ammonium polyphosphate APP n≥1000 Shanghai Aladdin Biochemical Technology Co., Ltd. Sodium hydroxide NaOH AR Beijing Bailingwei Technology Co., Ltd. Dopamine hydrochloride <![CDATA[C8H 11 NO2·HCl]]> AR Beijing Bailingwei Technology Co., Ltd. Sodium acetate trihydrate <![CDATA[CH3COONa·H2O]]> AR Beijing Bailingwei Technology Co., Ltd. Acetic acid <![CDATA[CH3COOH]]> 99.8％ Beijing Tonghua Fine Chemical Company Sodium periodate <![CDATA[NaIO4]]> 99.5%, AR Shanghai McLean Biochemical Technology Co., Ltd. Flame-retardant polyester fabric FRPET - self made Deionized water DI - self made

[0090] The flame-retardant polyester fabric FRPET used in the following examples was prepared by the following method:

[0091] Flame-retardant copolyesters were synthesized via direct esterification. First, the reactor was filled with nitrogen, and the airtightness of the apparatus was checked. Then, ethylene glycol (EG) and terephthalic acid (TPA) were added to a 2L reactor at a molar ratio of 1.2:1. Sb₂O₃ was added as a catalyst, and either DDP or 2-carboxyethylphenylphosphonic acid (CEPPA) was added as a flame retardant with a phosphorus content of 6500ppm. Nitrogen was then introduced to purge air from the reactor, and the pressure inside was controlled at 150 kPa. Stirring and heating were then initiated, and the esterification reaction was carried out under controlled temperature and pressure. When the water output reached one-third of the theoretical value, the valve was slightly opened to reduce the pressure until it reached zero. The final water output should be consistent with the calculated theoretical output. Finally, stabilizer TPP and antioxidant 1010 were added, and an esterification reaction was carried out at atmospheric pressure. After 3 hours of esterification, the polycondensation reaction begins. The temperature is gradually increased, the stirring rate is increased, and a vacuum is slowly drawn simultaneously to remove small molecules and promote the equilibrium reaction. After 30 minutes of low-vacuum reaction, the vacuum level in the reactor is maintained below 100 Pa, entering the high-vacuum stage. When the reaction system reaches a certain viscosity, the reactor rotation speed is reduced until the viscosity of the reaction system reaches the final discharge condition, at which point the reaction ends, and the material is discharged, granulated, and set aside. A single-screw spinning machine is used for melt spinning. The dried FRPET flame-retardant polyester is added to the feed port of the spinning machine. Under a certain screw pressure, the melt passes through a filter to remove small solid particles, and then is extruded through the spinneret. The extruded fibers are cooled and solidified by heat exchange with air to form nascent fibers. The nascent fibers are then stretched and heat-set on a forklift traction machine to obtain finished fibers, which are then woven into flame-retardant polyester fabric FRPET.

[0092] The MXene used in the following examples was prepared by ball milling-assisted LiF etching:

[0093] 2.0 g of Ti3AlC2 and LiF were placed in a 150 mL ball mill jar, and an appropriate amount of anhydrous ethanol was added. The mixture was ball milled for 24 h, and then placed in a fume hood to allow the ethanol to evaporate completely. 40.0 mL of HCl (9.0 mol / L) was added to a polytetrafluoroethylene container and stirred at room temperature for 30 min. Then, the ball-milled and dried Ti3AlC2 and LiF powders were added to the container, and the mixture was stirred and etched at 40 °C for 24 h.

[0094] The etched solution was centrifuged at 5000 rpm for 10 min. The precipitate was washed five times with deionized water until the pH of the supernatant was >6.0. The precipitate was further dispersed in ethanol and sonicated for 30 min, then the dispersion was centrifuged at 10000 rpm for 20 min. After separation, the precipitate was dispersed in a certain amount of deionized water, and then centrifuged again at 4000 rpm for 60 min to remove the unetched portion of MXene. After sonication for 15 min, an aqueous dispersion of MXene with a concentration of 10 mg / mL was obtained. Example 1: Alkali treatment of LBL to construct flame-retardant early warning polyester fabric

[0095] (1) Alkali modification treatment of FRPET fabric:

[0096] The fabric was immersed in a NaOH (1.0 mol / L) solution at 70°C for 1 hour, then washed with deionized water to remove the surface NaOH, and dried in a forced-air drying oven for 30 minutes.

[0097] (2) The dried fabric was immersed in PEI (positively charged, 0.5 wt%, pH=10) solution for 5 min and then dried for 30 min to obtain FRPET@PEI. The dried fabric FRPET@PEI was then immersed in PA (phytic acid, negatively charged, 3 wt%, pH=4) solution for 5 min and then dried for 30 min to complete the assembly of the (PEI / PA) bilayer and obtain FRPET@(PEI / PA).

[0098] (3) After assembling one (PEI+PA) bilayer, the fabric was immersed again in PEI (positively charged, 0.5wt%, pH=10) solution for 5 min, dried for 30 min, and then immersed in MXene solution (negatively charged, 10.0mg / mL) for 5 min, dried for 30 min to complete the assembly of (PEI / MXene) bilayer. The fabric was named FR@PM-1.

[0099] Repeat steps (2) and (3) above to obtain FRPET modified fabrics with different assembly layers. Define the two bilayers (PEI / PA) + (PEI / MXene) as a flame retardant warning functional layer. Prepare polyester fabrics with two flame retardant warning functional layers (PEI / PA) + (PEI / MXene) and name them FR@PM-2, and polyester fabrics with three flame retardant warning functional layers (PEI / PA) + (PEI / MXene) and name them FR@PM-3.

[0100] Example 2: Construction of flame-retardant early warning polyester fabric using dopamine crosslinked polyethyleneimine LBL

[0101] (1) Dopamine self-polymerization crosslinked polyethyleneimine modification treatment on the surface of FRPET fabric:

[0102] FRPET fabric was cut into 25cm×30cm rectangles and thoroughly washed with deionized water and anhydrous ethanol, then dried at 50℃ for 12h. The cut fabric was then completely immersed in a sodium acetate-acetic acid buffer solution (20mM, pH=5). A small amount of buffer solution was used to dissolve a certain amount of PEI, DA·HCl and NaIO4, and added to the remaining buffer solution. The concentration of PEI in the mixture was 1wt%, the concentration of dopamine was 2.0g / L, and the concentration of NaIO4 was 30mM. The reaction was carried out in a constant temperature shaker at room temperature (25℃) for 1h. Then, the fabric was rinsed repeatedly with deionized water 3 times and dried for 30min to obtain the modified FRPET@PDA / PEI fabric, which was named FPP.

[0103] (2) FPP was placed in a uniformly dispersed MXene solution (negatively charged, 10.0 mg / mL) and immersed for 5 min. After removal, it was dried for 30 min to obtain FPP@MXene. The dried FPP@MXene fabric was immersed again in PEI solution (positively charged, 0.5 wt%, pH=10) for 5 min, rinsed with deionized water and dried for 30 min. The dried fabric was then immersed in PA solution (negatively charged, 3 wt%, pH=4) for 5 min and dried for another 30 min to obtain a flame-retardant warning modified fabric with a (PEI / MXene) + (PEI / PA) bilayer, named FPP@PM-1.

[0104] (3) Repeat step (2) above to obtain flame-retardant warning modified fabric with two layers of (PEI / MXene) + (PEI / PA) bilayer, named FPP@PM-2, and flame-retardant warning modified fabric with three layers of (PEI / MXene) + (PEI / PA) bilayer, named FPP@PM-3.

[0105] Example 3: Construction of flame-retardant early warning polyester fabric using dopamine crosslinked polyethyleneimine LBL

[0106] (1) Dopamine self-polymerization crosslinked polyethyleneimine modification treatment on the surface of FRPET fabric:

[0107] Following the same steps (1) as in Example 2, FPP is obtained.

[0108] (2) The FPP fabric was immersed in a uniformly dispersed MXene solution (negatively charged, 10.0 mg / mL) for 5 min, and then hung to dry for 30 min to obtain FPP@MXene; the dried fabric was immersed in PEI (positively charged, 0.5 wt%, pH=10) solution for 5 min, rinsed with deionized water and dried for 30 min; the dried fabric was then immersed in the prepared APP solution (ammonium polyphosphate, negatively charged, 1 wt%, pH=4) for 5 min, rinsed with deionized water and then dried for 30 min to obtain a flame-retardant warning modified fabric with a (PEI / MXene) + (PEI / APP) bilayer, named FPP@AM-1.

[0109] (3) Repeat step (2) above to obtain flame-retardant early warning modified fabric with two layers of (PEI / MXene) + (PEI / APP) bilayer, named FPP@AM-2, and flame-retardant early warning modified fabric with three layers of (PEI / MXene) + (PEI / APP) bilayer, named FPP@AM-3.

[0110] Example 4: Construction of flame-retardant early warning polyester fabric using dopamine crosslinked polyethyleneimine LBL

[0111] (1) Dopamine self-polymerization crosslinked polyethyleneimine modification treatment on the surface of FRPET fabric:

[0112] Following the same steps (1) as in Example 2, FPP is obtained.

[0113] (2) The prepared FPP fabric was immersed in APP solution (ammonium polyphosphate, negatively charged, 1 wt%, pH=4) for 5 min, then rinsed with deionized water and dried for 30 min to obtain a modified polyester fabric with a layer of (PEI / APP), named FPP@APP.

[0114] (3) The modified polyester fabric FPP@APP obtained in step (2) is immersed in PEI solution (positively charged, 0.5wt%, pH=10) for 5 min, rinsed with deionized water, dried for 30 min, and then step (2) is repeated to obtain modified polyester fabrics with 3 layers (PEI / APP) and 5 layers (PEI / APP) respectively.

[0115] (4) The three modified polyester fabrics (with one layer of PEI / APP, three layers of PEI / APP and five layers of PEI / APP) were immersed in PEI solution (positively charged, 0.5 wt%, pH=10) for 5 min, rinsed with deionized water and dried for 30 min. Then the dried fabrics were immersed in a uniformly dispersed MXene solution for 5 min and dried for 30 min to obtain modified polyester fabric FPP@A1-M1 with one layer (PEI / APP) and one outermost layer (PEI / MXene), modified polyester fabric FPP@A3-M1 with three layers (PEI / APP) and one outermost layer (PEI / MXene), and modified polyester fabric FPP@A5-M1 with five layers (PEI / APP) and one outermost layer (PEI / MXene).

[0116] Performance Test 1: Morphology and Structural Characterization

[0117] The surface microstructure of the modified fabrics prepared in Examples 1-4 was characterized using a JSM-7500F scanning electron microscope manufactured by Nippon Electronics Corporation.

[0118] SEM images of the FR@PM series modified fabrics prepared in Example 1 are shown below. Figure 1 As shown. From Figure 1 It can be seen that the fabric structure before and after modification is basically the same, and with the increase of the number of assembled layers, the polyester fabric fibers change from smooth to rough, and a clear coating appears on the fiber surface. From Figure 1 As can be seen from (a) to (c), compared to the original FRPET fiber, the surface of the FRPET fiber treated with alkali becomes rougher. This is because, under alkaline conditions, some ester bonds in the fiber macromolecular chain segments are broken, generating free carboxyl and hydroxyl groups, resulting in a certain degree of fiber damage. However, the surface of the fabric after alkali treatment is conducive to the adhesion of positively charged PEI solution in the solution. From Figure 1 As can be seen from (d) to (f), during the LBL assembly process of PEI / PA / PEI / MXene, as the number of layers increases, the surface covering in the fiber increases and the coating becomes thicker, indicating an increase in the amount of polyelectrolyte.

[0119] SEM images of the modified fabrics prepared in Examples 2 and 3 are shown below. Figure 2 As shown. From Figure 2 As shown in (a), dopamine PDA adheres to PEI during self-polymerization on the FRPET surface, imparting surface charge to the FPP and providing a good pre-charged layer for the assembly of the next negatively charged polyelectrolyte layer. From Figure 2(b) It can be seen that, compared to alkali-treated FRPET assembling PEI, the electrostatic force is more pronounced, and MXene can be evenly distributed on the FPP fabric, which is beneficial for layer-by-layer self-assembly. From Figure 2 (c)~(e) and Figure 2 (f)~(h) show that, compared with FPP@PM, the flame retardant molecules and MXene nanolayers are more evenly distributed on FPP during self-assembly of FPP@AM.

[0120] SEM image of the modified fabric prepared in Example 4 is shown below. Figure 3 As shown. From Figure 3 (a) It can be seen that the APP is arranged very tightly on the fiber surface of FPP@APP. The tightly arranged APP flame retardant layer will improve the quality of the char layer after combustion and stick the char layers together so that they can effectively insulate heat transfer. Figure 3 As can be seen from (b) to (d), with the increase of the number of (PEI / APP) assembly layers, the thickness of the fiber surface coating increases significantly, and with MXene as the outermost layer, the coating surface shows obvious "groove" appearance.

[0121] Performance Test 2: Thermal Stability Characterization

[0122] Thermogravimetric analysis (TG) was performed on FRPET fabrics, as well as FPP and FPP@PM-3 prepared in Example 2, FPP@AM-3 prepared in Example 3, and FPP@A5-M1 prepared in Example 4, using a Netzsch TG 209F1 thermogravimetric analyzer under N2 atmosphere, in a temperature range of 30–700 °C, at a heating rate of 10 °C / min. The TG curves are shown below. Figure 4 As shown.

[0123] from Figure 4 As can be seen, except for FPP@A5-M1 which began to decompose prematurely at around 300℃, all other samples began to decompose at 350℃, exhibiting a two-stage thermal degradation process, mainly attributed to the thermal decomposition of FRPET. This is primarily due to the relatively low loading of the LBL layer, which did not significantly affect the thermal stability of the FRPET matrix. Comparing FPP@PM-3 and FPP@AM-3, the LBL functional fabric using APP as a flame retardant had a 43.16% higher residue percentage at 700℃ than the LBL modified early warning fabric using PA as a flame retardant, indicating that APP has better char formation efficiency than PA, which can improve the formation of char residue during fabric combustion and thus improve flame retardant efficiency. The residue mass of FPP@A5-M1 further increased to 13.12%, also verifying the above hypothesis.

[0124] Performance Test 3: Combustion and Flame Retardant Performance Test

[0125] Cone calorimetry was performed using a cone calorimeter from Fire Testing Technology Ltd. (UK). The sample size was 100mm × 100mm, with four layers stacked. The instrument's radiant power was 35kW / m². 2 The sample size for the FPP@PM, FPP@AM, and FPP@AM series is 20mm × 20mm, stacked in 4 layers, and the instrument's radiation power is 50kW / m². 2 The samples were tested according to ISO 5660-1-2002 "Cone calorimetry".

[0126] The CONE test results of the FR@PM series flame-retardant early warning fabric in Example 1 are shown in Table 2 and Figure 5 As shown in Table 2, the loading of the FRPET@PM surface coating increases with the increase of the number of assembled layers. Furthermore, the increased PEI polyelectrolyte covering the fabric surface leads to increased fabric surface viscosity, which is beneficial for the assembly of polyelectrolytes with opposite charges. With increasing PA content, the pHRR of the modified polyester fabric significantly decreases. Compared to FRPET, the pHRR of FR@PM-3 decreases by 62.7%, indicating a significant effect of the coating in delaying heat release. This is because PA has a high phosphorus content, and its thermal decomposition generates a large number of phosphorus free radicals, effectively capturing free radicals generated during matrix combustion, thus delaying combustion. In addition, the 45.7% increase in char residue may be due to the expansion flame-retardant effect of PA, leading to a gradual increase in char residue.

[0127] Table 2. CONE data for FR@PM series flame-retardant warning fabrics.

[0128]

[0129] The heat release rate curves of FR@PM series fabrics are as follows: Figure 5 As shown, the addition of the (PEI+PA) flame retardant layer significantly reduces the peak heat release rate (pHRR) of the fabric. However, with the increase in the number of LBL layers, the ignition time of the fabric combustion is shortened, and the probability of the fabric being ignited increases.

[0130] The CONE test results of the FPP@PM series flame-retardant early warning fabric prepared in Example 2 are shown in Table 3 and Figure 6 As shown in Table 4, the CONE test results of the FPP@AM series flame-retardant early warning fabric prepared in Example 3 are shown in Table 4. Figure 7 As shown.

[0131] Table 3. CONE Data for FPP@PM Series Flame Retardant Warning Fabrics

[0132]

[0133] Table 4. Cone data for FPP@AM series modified flame-retardant early warning fabrics

[0134]

[0135] Table 3 shows that, compared to FRPET, functionalized FRPET@PDA / PEI (FPP) exhibits increased pHRR, total heat release (THR), and total smoke release (TSP). This indicates that the single-layer PDA / PEI functional layer does not inhibit the heat release and smoke production of FRPET; on the contrary, it enhances both. This is mainly because PDA and PEI are rich in C and N elements, making them easily combustible. However, the addition of PA slightly decreases the pHRR and TSP values, but has a minor effect on THR. This suggests that the synergistic expansion of PEI and PA in the self-assembled layer blocks heat transfer, reduces smoke production, and effectively improves char residue in conjunction with the MXene layer. This phenomenon indicates that flame-retardant treatment of FRPET with the self-assembled coating can promote stable char formation and, to a large extent, exhibits anti-dripping effects in the experiment.

[0136] From Table 3 and Figure 6 It can be seen that, compared with FRPET, the heat release rate of the dopamine self-polymerized crosslinked PEI modified fabric did not change significantly, and the presence of (PEI / PA) reduced pHRR and TSP.

[0137] From Table 4 and Figure 7 It can be seen that, compared with the FPP@PM series fabrics, the FPP@AM series fabrics have better flame retardant and smoke suppression effects, resulting in lower TSP and pHRR peak values. This indicates that, compared with (PEI / PA), (PEI / APP) plays a better role in heat insulation and smoke suppression in flame retardant warning modified fabrics.

[0138] Furthermore, APP exhibits a higher coating amount than PA in the self-assembly of FPP-modified fabrics, which also leads to an increase in char residue. As an intumescent flame retardant, APP can also synergistically work with PEI to expand and block heat and gas diffusion at high temperatures. Notably, compared to PA, while APP-based FPP-modified fabrics do not show significant changes in THR and TSP inhibition, they show a slight advantage in reducing pHRR. Layered APP retains some ammonium metaphosphate and other substances after combustion, increases the density of the surface char layer, releases non-combustible gases, and reduces the heat release of the sample.

[0139] The CONE test results of the FPP@AM series flame-retardant early warning fabric prepared in Example 4 are shown in Table 5 and Figure 8 As shown.

[0140] Table 5. Cone data for FPP@AM series modified flame-retardant early warning fabrics

[0141]

[0142]

[0143] FPP@A1-M1 is an experimental sample prepared by optimizing the LBL process of FPP@AM. The two differ in the placement of the flame retardant layer and the warning coating. This fabric is assembled with five (PEI / APP) flame retardant coatings and one (PEI / MXene) warning coating (outermost layer) on top of the FPP layer. Compared to FPP@AM, the coating amount is reduced, and although the smoke emission is slightly increased, the sample shows better performance in suppressing pHRR and THR based on the total heat release. The results indicate that compared to alternating assembly of the APP flame retardant layer and the MXene warning layer, the continuous (PEI+APP) coating during LBL treatment provides better insulation against external heat transfer, resulting in less harm to the surrounding area during fire warning.

[0144] Performance Test 4: Thermoelectric Performance and Fire Early Warning Test

[0145] Using FPP@PM-3 prepared in Example 2, FPP@AM-3 prepared in Example 3, and FPP@A5-M1 prepared in Example 4 as samples, their thermoelectric properties and fire warning performance were tested. The results are shown in Table 6 and... Figures 9-11 As shown. Five tests were performed on the sample at each temperature and each trigger threshold at room temperature, and the average value was taken.

[0146] As shown in Table 6, when comparing FPP@PM-3 and FPP@AM-3 with PA and APP as flame retardant layers respectively, the former has weaker thermoelectric performance. The maximum thermoelectric potential generated at the temperature difference between the two ends of the sample is 0.54mV, and the Seebeck coefficient is 4.6μV / K. In the fire warning experiment, considering the sample size, the highest trigger threshold value is only 0.4mV, and the duration is as long as 9s. The flame retardant warning fabric based on APP has a slight advantage in comparison.

[0147] from Figure 9 It can be seen that the thermoelectric potential-temperature difference curves fitted by FPP@AM-3 fabric have a high linear correlation within a temperature difference of less than 90℃. The Seebeck coefficient within this temperature difference is as high as 12.25μV / K, which is much higher than that of FPP@PM-3 and FPP@A5-M1. However, after the temperature difference exceeds 90℃, the thermoelectric performance becomes unstable and a lower thermoelectric potential is generated. This is due to the complex alternating assembly of the APP layer and the MXene layer, which affects the ion transport of the MXene warning layer when heated at 100-300℃.

[0148] Table 6. Thermoelectric properties of three FPP modified fabrics and warning times at different threshold values.

[0149]

[0150] The results show that FPP@AM-3 has a higher and more sensitive thermoelectric potential during fire warning, which is better than FPP@PM-3 using the same LBL process. When the direct contact flame temperature is higher than 300℃, the thermal decomposition of APP does not significantly affect the ion transport of the MXene warning layer, and it can still provide a warning in about 5.5s at a trigger voltage of 0.8mV. This is the opposite of the effect of PA on the MXene warning layer at low and high temperatures, which also explains why FPP@PM-3 does not have a higher trigger voltage.

[0151] Figure 10 The results show that, compared with FPP@PM-3 and FPP@AM-3, FPP@A5-M1 can stably exert the early warning function of MXene in a wider temperature range. Due to its continuous (PEI / APP) self-assembled flame retardant layer, it combines the advantages of both. At a low trigger voltage of 0.4mV, it can still achieve a fire warning of about 6s. Its thermoelectric performance also tends to be stable within a temperature difference of 50-130℃.

[0152] In addition, this application also assembled an additional (PEI / MXene) warning layer on the basis of FPP@A5-M1, named FPP@A5-M2. When measuring thermoelectric performance and fire warning, this sample did not have a higher Seebeck coefficient, and the thermoelectric potential generated at 130℃ and the warning time of the 0.4mV and 0.5mV threshold values ​​were also very similar to FPP@A5-M1. This indicates that more (PEI / MXene) warning layers do not increase its ion transport rate when heated.

[0153] Infrared cameras were used to test the instantaneous temperature of FRPET and FPP flame-retardant early warning modified fabrics during combustion, such as... Figure 11 As shown, FPP@PM-3 and FPP@AM-3 affected the surface temperature of FRPET during combustion, but sample FPP@A5-M1 had better heat insulation effect. This is due to the presence of a continuous (PEI / APP) flame retardant layer. The surface temperature was only about 300℃ after 5 seconds of contact with the flame, which is better than the flame retardant and heat insulation effect of the modified fabrics of FPP@PM and FPP@AM series. The surface temperature was reduced by about 32% compared with FRPET during combustion. In the layer-by-layer self-assembly of the flame retardant early warning fabric, APP played a better role in heat insulation than PA. The continuous assembly of APP flame retardant played an excellent role in the modified fabric, which provides a new solution for early fire warning.

[0154] The technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made in accordance with the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. A fire-retardant and early warning fabric, comprising a fabric substrate and at least one flame-retardant layer and at least one early warning layer coated on the surface of the fabric substrate, wherein the flame-retardant layer comprises a cationic polymer-flame retardant coating unit, and the early warning layer comprises a cationic polymer-early warning material coating unit, wherein the flame retardant and the early warning material are negatively charged; The flame retardant layer consists of 3 to 5 layers, and the warning layer consists of 1 layer, with the warning layer located on the outermost layer of the fabric substrate surface; The flame-retardant layer includes a polyethyleneimine-ammonium polyphosphate coating unit; The warning layer includes a polyethyleneimine-MXene coating unit; The MXene was obtained by chemical etching of Ti3AlC2. The preparation method of the fire-prevention and flame-retardant fabric includes the following steps: (1) The fabric is pretreated with an alkaline substance and then immersed in a solution containing a cationic polymer and dried, or the fabric is immersed in a solution containing a self-polymerizable monomer and a cationic polymer and dried to obtain a fabric coated with a cationic polymer. (2) The fabric with the surface coated with the cationic polymer is immersed in a solution containing the flame retardant and dried to obtain a fabric with a flame retardant layer on the surface; the obtained fabric with a flame retardant layer on the surface is immersed in a solution containing the cationic polymer, dried, and then immersed in a solution containing the flame retardant and dried again. The operation is repeated to obtain a fabric with 3 to 5 flame retardant layers on the surface. (3) The fabric obtained in step (2) is immersed in a solution containing cationic polymer, dried, and then immersed in a solution containing the warning material. After drying, a fabric with 3 to 5 flame retardant layers and one warning layer coated on the surface is obtained. In steps (2) and (3), the concentration of the cationic polymer in the solution containing the cationic polymer is 0.1 wt% to 10 wt%; the concentration of the warning material in the solution containing the warning material is 5 to 100 mg / mL; the concentration of the flame retardant in the solution containing the flame retardant is 1 wt% to 20 wt%; and the impregnation time is 2 to 30 min.

2. The fire-retardant and flame-retardant fabric according to claim 1, characterized in that, The fabric includes at least one of the following fabrics, modified or unmodified: polyester fabric, cotton fabric, linen fabric, acrylic fabric, polypropylene fabric, nylon fabric, vinylon fabric, polyester / cotton blend fabric, viscose fiber fabric, and Lyocell fiber fabric.

3. The fire-retardant and flame-retardant fabric according to claim 2, characterized in that, The fabric is a polyester fabric modified with phosphorus-based flame retardants.

4. The fire-retardant and flame-retardant fabric according to claim 3, characterized in that, The fabric is a polyester fabric modified with 2-carboxyethylphenylphosphine or [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphazenecyclo-6-yl)methyl]succinic acid.

5. The fire-retardant and flame-retardant fabric according to claim 1, characterized in that, In step (1), the alkaline substance includes at least one of alkali metal hydroxides and alkaline earth metal hydroxides; and / or, In step (1), the concentration of the cationic polymer in the solution is 0.1 wt% to 10 wt%; and / or, The self-polymerizable monomer includes dopamine and / or dopamine analogs, the structure of which is shown in Formula I below. Formula I In Formula I, R1, R2, and R4 may be the same or different, and each is independently selected from halogen, cyano, hydroxyl, carboxyl, branched or straight-chain alkyl with 1 to 10 carbon atoms, cycloalkyl with 3 to 12 carbon atoms, alkoxy with 1 to 10 carbon atoms, aryloxy with 6 to 20 carbon atoms, aryl with 6 to 20 carbon atoms, or heteroaryl with 3 to 20 carbon atoms; R3 is selected from branched or straight-chain alkyl with 1 to 10 carbon atoms, cycloalkyl with 3 to 12 carbon atoms, alkoxy with 1 to 10 carbon atoms, aryloxy with 6 to 20 carbon atoms, aryl with 6 to 20 carbon atoms, or heteroaryl with 3 to 20 carbon atoms; The solution containing self-polymerizable monomers and cationic polymers also includes a buffer solution, which comprises a tris(hydroxymethyl)aminomethane salt solution system and / or a sodium acetate-acetic acid buffer solution of NaIO4. And / or, The immersion time in the solution containing cationic polymer is 2-30 min; the immersion time in the solution containing self-polymerizable monomers and cationic polymers is 30-180 min.

6. The fire-retardant and flame-retardant fabric according to claim 5, characterized in that, The solution containing the self-polymerizable monomer and the cationic polymer has a cationic polymer concentration of 0.1 wt% to 10 wt% and a self-polymerizable monomer concentration of 1 to 10 g / L; the pH of the tris(hydroxymethyl)aminomethane salt system is 8 to 9.5, the NaIO4 concentration is 25 to 35 mM, the sodium acetate-acetic acid buffer solution concentration is 10 to 30 mM, and the pH is 4.0 to 5.

5.

7. The fire-retardant and flame-retardant fabric according to claim 5, characterized in that, In step (1), the alkaline substance includes one or more of sodium hydroxide, potassium hydroxide, and calcium hydroxide; and / or, In step (1), the concentration of the cationic polymer in the solution is 0.25 wt% to 1.0 wt%; and / or, In the solution containing self-polymerizable monomers and cationic polymers, the concentration of cationic polymers is 0.5 wt% to 1.5 wt%, and the concentration of self-polymerizable monomers is 1.5 to 2.5 g / L.

8. The fire-retardant and flame-retardant fabric according to claim 1, characterized in that, In steps (2) and (3), the concentration of the cationic polymer in the solution is 0.25 wt% to 1.0 wt%; and / or, In solutions containing early warning materials, the concentration of the early warning materials is 5–30 mg / mL; and / or, In the solution containing flame retardant, the concentration of flame retardant is 1 wt% to 5 wt%.

9. The application of the fire-prevention and flame-retardant fabric according to any one of claims 1 to 8 in fire warning products and / or flame-retardant products.

Images