An organophosphate intercalated layered metal hydroxide flame-retardant and smoke-suppressing hybrid material, its preparation method and application

Abstract

This invention discloses an organophosphate intercalated layered metal hydroxide flame-retardant and smoke-suppressing hybrid material, its preparation method, and its application. Addressing the limitations of traditional layered metal hydroxide smoke suppressants, such as component singularity, functional imbalance, and poor process economy, this invention provides an organophosphate intercalated layered metal hydroxide flame-retardant and smoke-suppressing hybrid material. To address the problem of uneven dispersion and reduced mechanical properties of traditional LDH in polymer matrices, this invention constructs a novel smoke-suppressing and flame-retardant hybrid material with a novel structure through cation regulation and organophosphate intercalation. Through theoretical calculations and performance analysis, this invention utilizes interface regulation to construct a novel smoke-suppressing and flame-retardant polymer material. When applied to polymer matrix processing, it achieves excellent flame-retardant and smoke-suppressing effects without causing pollution to the environment or human health.

Description

Technical Field

[0001] This invention belongs to the field of flame retardant materials, specifically relating to an organophosphate intercalated layered metal hydroxide flame retardant and smoke-suppressing hybrid material, its preparation method, and its application. Background Technology

[0002] Thermoplastic polyurethane (TPU) is widely used in wire and cable sheathing, automotive interiors, electronic devices, and medical devices due to its excellent abrasion resistance, high elasticity, and processing properties. However, as a polymer material, TPU typically has a limiting oxygen index (LOI) below 20%, classifying it as flammable. During combustion, it releases large amounts of dense smoke and toxic gases (such as carbon monoxide, hydrogen cyanide, and nitrogen oxides). Especially in confined spaces or high-density electrified environments (such as underground rail transit and data centers), the smoke from TPU combustion can severely hinder escape, exacerbate fire hazards, and cause persistent environmental pollution. Therefore, developing TPU composite materials that combine highly efficient flame retardancy and smoke suppression has become an urgent need to ensure public safety and meet environmental regulations.

[0003] To ensure industrial safety and protect the ecological environment, developing thermoplastic polyurethane (TPU) composites with both high-efficiency flame retardancy and smoke suppression properties has become a key research topic. In related technological fields, layered bimetallic hydroxides (LDHs) are considered ideal candidate systems for environmentally friendly flame-retardant and smoke-suppressing materials due to their unique, controllable lamellar structure and endothermic thermal decomposition characteristics. In the future, developing environmentally friendly, halogen-free, and highly efficient TPU smoke suppression technologies will be a research hotspot, with continued exploration of more environmentally friendly and efficient methods, and their widespread application in fields such as intelligent manufacturing and sustainable development.

[0004] In recent years, research on LDH flame-retardant and smoke-suppressing TPU has mainly been divided into three types: LDH synergistically flame-retardant and smoke-suppressing TPU with traditional flame retardants (such as ammonium polyphosphate and aluminum diethylphosphite) (Polym. Degrad. Stab, 2022, 202: 110043.Polym. Degrad. Stab, 2019, 165: 126-136.), LDH synergistically flame-retardant and smoke-suppressing TPU with high-efficiency phosphorus-containing flame retardants (such as DOPO and PEI) (Appl. Clay Sci., 2024, 258: 107489. Polym. Degrad. Stab, 2020,178: 109179.), and LDH synergistically flame-retardant and smoke-suppressing TPU with inorganic layered materials (such as Mxene and MoS2) (J. Polym. Sci.,2024, 62(24): (5693-5705., Constr. Build. Mater., 2024, 457: 139478.). However, the application of traditional LDH flame retardants and smoke suppressants still has certain problems. In existing technologies, many studies have attempted to improve the flame retardant properties of LDH by regulating its cationic composition or anionic intercalation, but significant drawbacks remain:

[0005] Single type of cation: Traditional LDHs often use 2-3 metal combinations (such as Mg-Al, Zn-Fe), resulting in uneven charge density distribution on the plates, which limits the free radical capture efficiency and the adsorption capacity of toxic gases.

[0006] Anion functional disruption: conventional intercalating anions (NO3) - CO3² - (etc.) only exert physical barrier or gas phase dilution effects, lacking a chemical synergistic mechanism with flame-retardant and smoke-suppressing active components;

[0007] Structure-function imbalance: Cation regulation and anion intercalation are mostly optimized in isolation, failing to achieve simultaneous improvement in flame retardant and smoke suppression performance through interionic electronic coupling effects.

[0008] The application of anionic phosphate intercalated layered metal hydroxide (CN110218508A) as a flame retardant material aims to improve the flame retardant properties and mechanical properties of epoxy acrylate flame retardant materials through phosphate intercalation technology. However, this work shows a relatively low reduction in the flame retardant performance of the material and lacks characterization and research on smoke, indicating insufficient research on the material. The use of organophosphate intercalated layered metal hydroxide (CN115926812A) as a composite flame retardant material for electrodes, while still using organophosphate to intercalate layered metal hydroxide as an additive for battery separators or negative electrode sheets, shows only a slight increase in the oxygen index of the composite material after adding the flame retardant. Most of the matrix material remains at the standard level for flammable materials. Furthermore, the flame retardant and smoke performance are not specifically analyzed and characterized. The composite material has a large addition of flame retardant (30%-50%), resulting in significant differences in mechanical properties. The mechanism and function of organophosphate are not clearly elucidated. Although there has been considerable research on composite organic acid intercalated layered metal hydroxides as flame retardant materials, their application in high-performance TPU materials remains lacking. Designing an organic phosphate intercalated layered metal hydroxide as a low-addition, high-flame-retardant, smoke-suppressing, and toxicity-reducing hybrid material for TPU has significant research value. Summary of the Invention

[0009] To address the problems existing in the prior art, this invention provides an organophosphate intercalated layered metal hydroxide flame-retardant and smoke-suppressing hybrid material, its preparation method, and its application.

[0010] This invention constructs a novel smoke-suppressing and smoke-reducing hybrid material with a smoke-suppressing-flame-retardant structure through cation regulation and organophosphate intercalation. This material is then used in the processing of a polymer matrix to achieve excellent flame-retardant and smoke-suppressing / toxicity-reducing effects, while being pollution-free to the environment and human health. The preparation process of this smoke-suppressing and toxicity-reducing composite material is low-cost, simple and environmentally friendly, highly controllable, and suitable for mass production.

[0011] The present invention discloses a method for preparing an organophosphate intercalated layered metal hydroxide flame-retardant and smoke-suppressing hybrid material, which employs a hydrothermal in-situ intercalation method and includes the following steps:

[0012] Step 1: Mix the divalent and trivalent metal salts and dissolve them in deionized water. Add the precipitant and organophosphate compound, and stir continuously at a temperature of 25-30℃ to mix evenly and obtain a suspension.

[0013] Step 2: Transfer the suspension obtained in Step 1 to a high-pressure reactor and carry out a hydrothermal reaction at 100℃-150℃. Filter to obtain the precipitate, wash with ethanol and deionized water, and dry to obtain the organophosphate intercalated LDH hybrid material.

[0014] In step 1, the active metal components in the divalent and trivalent metal salts include one or more of iron, cobalt, nickel, copper, and magnesium. The total metal salt content is 0.5-1 mol / L. The organic phosphate content is 0.4-2 mol / L.

[0015] Furthermore, in the divalent and trivalent metal salts, the molar ratio of the divalent metal to the trivalent metal is 2:1 to 3:1, such as 2:1, 2.5:1, or 3:1.

[0016] Furthermore, the divalent metal is Ni. 2+ Co 2+ Cu 2+ Mg 2+ One or more of the following, with Fe as a trivalent metal. 3+ .

[0017] The precipitant is an aqueous solution of triethanolamine, and the molar ratio of the precipitant to the metal salt is between 2:1 and 4:1.

[0018] The organophosphate compound is phenylphosphine (PPA) or diphenylphosphine (DPA), and the molar ratio of organophosphate to metal salt is between 1:2 and 1:2.

[0019] In the organophosphate intercalated layered metal hydroxide flame retardant and smoke suppressant hybrid material of the present invention, the layered metal hydroxide exhibits a stacked sheet, whisker or rod structure with a particle size of 30nm-2μm.

[0020] The application of the organophosphate intercalated layered metal hydroxide flame retardant and smoke suppressant hybrid material of the present invention involves adding the organophosphate intercalated layered metal hydroxide as an additive to thermoplastic polyurethane to improve the flame retardant and smoke suppressant properties of the material.

[0021] Furthermore, when the organophosphate intercalated layered metal hydroxide is added as an additive to thermoplastic polyurethane, the TPU composite material is constructed using a melt blending method, including the following steps:

[0022] (1) The TPU masterbatch is dried in an oven to remove moisture.

[0023] (2) Add the dried TPU masterbatch to a mixer to melt it, and add the organic phosphate intercalated LDH hybrid material to mix it evenly to obtain the TPU composite material.

[0024] (3) The TPU composite material is hot-pressed on a flat vulcanizing machine to obtain a regular sheet.

[0025] Furthermore, the amount of the organic phosphate intercalated LDH hybrid material added is 1-3 wt% of the total mass of the polymer composite material.

[0026] In the present invention:

[0027] Cation-based multi-component design: Introducing Fe 3+ / Cu 2+ / Co 2+ / Ni 2+ / Mg 2+ High charge density layers are constructed using multivalent metals to enhance free radical quenching and chemisorption of acidic gases (HCl, HCN).

[0028] Anion functionalized intercalation: Organic phosphate intercalation is adopted. Its abundant phosphate groups not only improve the char residue rate (>35%) by catalytic char formation, but also form POM covalent bonds with polymetallic cations to stabilize the laminate structure (thermal stability >400℃).

[0029] Synergistic effect of ions: The multi-metallic cations and organophosphate anions in the layer are constructed through charge matching and electron transfer channels to achieve a synergistic dual flame retardant-smoke suppression mechanism of condensed phase char formation and gas phase free radical inhibition, which significantly reduces smoke toxicity (CO generation is reduced by 64%).

[0030] This invention addresses the problems of high cost, high toxicity, and poor flame retardancy of current thermoplastic polyurethane (LDH) materials by providing an organophosphate intercalated layered metal hydroxide (LDH) flame-retardant and smoke-suppressing hybrid material, its preparation method, and its applications. Unlike traditional flame retardants that contain large amounts of toxic elements and may negatively impact the environment and health, potentially releasing large amounts of toxic gases during combustion, this invention addresses the problems of traditional LDHs by focusing on the dual requirements of optimized flame retardant performance and low smoke and toxicity. It achieves multiple benefits, including optimized process economy and mechanical properties, thus balancing synergistic flame retardancy, smoke suppression, and other properties.

[0031] The beneficial effects of this invention are reflected in:

[0032] 1. This invention addresses the limitations of traditional LDH (Liquid Hydrogen Deposition) materials, such as the single component, functional imbalance, and poor process economy, by providing an organophosphate intercalated layered metal hydroxide flame-retardant and smoke-suppressing hybrid material. Through surface reconstruction and metal element regulation, the formation of defect sites and lattice oxidation in LDH are promoted, revealing the changing patterns of LDH's influence on polymer combustion exothermics and smoke toxicity. Molecular dynamics and theoretical analysis methods are used to effectively predict the anionic interlayer spacing and intercalation structure of LDH, and to deeply analyze the breakage and recombination of functional groups during combustion. Through highly efficient synergistic flame retardancy, it is used to prepare polyurethane composite materials, achieving high smoke suppression and flame retardant efficiency with low addition amounts.

[0033] 2. This invention prepares composite materials via a one-step hydrothermal method. The process is short, uses inexpensive raw materials, does not involve flammable or explosive reagents, and offers controllable process control with high precision in metal ratio adjustment. This method has significant reference value for industrial production. When applied to the processing and production of thermoplastic polyurethane elastomers, it achieves the dual requirements of high-efficiency flame retardancy optimization and low smoke and low toxicity, realizing multiple effects of process economy and mechanical property optimization. Furthermore, it is safe and environmentally friendly, reducing environmental pollution and making it suitable for practical applications.

[0034] 3. The preparation process of this invention is simple, green, low in production cost, simple in process, and high in efficiency. Through theoretical calculation and performance analysis, a novel smoke-suppressing and flame-retardant polymer material is constructed through interface regulation. Attached Figure Description

[0035] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 The images show scanning electron microscope (SEM) images of Ni-Fe LDH prepared by different methods in Examples 1-4. Specifically: a) is an SEM image of Ni-Fe LDH prepared in Example 1 using triethanolamine as a precipitant, showing a stacked lamellar structure with dimensions of 20-50 nm (a1 and a2 represent different magnification scales); b) is an SEM image of Ni-Fe LDH prepared in Example 2 using urea as a precipitant, showing a stacked whisker structure with dimensions of 500 nm-1 μm (b1 and b2 represent different magnification scales); c) is an SEM image of Ni-Fe LDH prepared in Example 3 by freeze-drying via co-precipitation, showing a stacked rod-like structure with dimensions of 1 μm-5 μm (c1 and c2 represent different magnification scales); d) is an SEM image of Ni-Fe LDH prepared in Example 4 by oven drying via co-precipitation, showing a stacked granular structure with dimensions of 50 nm-100 nm (d1 and d2 represent different magnification scales). In the preferred embodiment 1, the Ni-Fe LDH prepared by using triethanolamine as a hydrothermal precipitant was used in subsequent experiments. The stacked small lamellar structure is the optimized structure of LDH.

[0038] Figure 2Scanning electron microscope (SEM) images of Ni-Fe LDH prepared with reactants of different ratios in Example 5 are shown. Specifically: a and b are morphological images of LDH with a Ni:Fe ratio of 1:4, where the LDH material exhibits an independent spherical structure; c and d are morphological images of LDH with a Ni:Fe ratio of 1:3, where the LDH material exhibits an irregular and somewhat adherent spherical structure; e and f are morphological images of LDH with a Ni:Fe ratio of 1:2, where the LDH material exhibits an adherent spherical structure; g and h are morphological images of LDH with a Ni:Fe ratio of 1:1, where the LDH material exhibits an adherent, irregular spherical structure; i and j are morphological images of LDH with a Ni:Fe ratio of 2:1, where the LDH material exhibits an adherent, small lamellar structure; k and l are morphological images of LDH with a Ni:Fe ratio of 3:1, where the LDH material exhibits a large number of adherent, small lamellar structures. A preferred reactant ratio of Ni:Fe of 2:1 was used for subsequent experiments to ensure the lamellar structure of the LDH.

[0039] Figure 3 The images show scanning electron microscope (SEM) images of Ni-Fe LDH prepared at different hydrothermal reaction temperatures in Example 6. Specifically: a and b are SEM images of Ni-Fe LDH prepared at a hydrothermal temperature of 60°C, showing an irregular small lamellar structure; c and d are SEM images of Ni-Fe LDH prepared at a hydrothermal temperature of 90°C, showing a stacked small lamellar structure; e and f are SEM images of Ni-Fe LDH prepared at a hydrothermal temperature of 110°C, showing a stacked large lamellar structure; g and h are SEM images of Ni-Fe LDH prepared at a hydrothermal temperature of 130°C, showing a stacked rod-like structure. A hydrothermal temperature of 110°C is preferred for subsequent experiments to ensure the lamellar structure of the LDH.

[0040] Figure 4The thermogravimetric temperature (TGA) curves and scanning electron microscope (SEM) images corresponding to different TGA temperatures of Ni-Fe LDH prepared in the preferred embodiment 1 are shown. Specifically: a) is the TGA temperature and derivative TGA curves of Ni-Fe LDH under nitrogen atmosphere. The figure shows multiple weight loss peaks in LDH, indicating the removal of different substances under heating conditions, corresponding to the removal of adsorbed H2O, interlayer CO2, interlayer H2O, and the formation of metal oxides. b) is the SEM image of the LDH morphology, and c) is the SEM image of LDH corresponding to the weight loss peak at approximately 100℃, indicating the removal of adsorbed H2O; the material still retains a small lamellar structure. Image d shows the SEM image of the weight loss peak of Ni-Fe LDH around 300℃-380℃, corresponding to the removal of interlayer CO2 and the gradual aggregation of small lamellar layers. Image i shows the SEM image of the weight loss peak of Ni-Fe LDH around 380℃-460℃, corresponding to the removal of interlayer H2O and the initial formation of metal oxides. Image j shows the SEM image of the weight loss peak of Ni-Fe LDH around 600℃, corresponding to the complete formation of metal oxides and the continuous aggregation of metal particles. Images e and f are transmission electron microscopy (TEM) images of the morphology of LDH, showing a small lamellar structure. Images g and h are TEM images of the morphology of LDH after thermogravimetric analysis, showing an aggregated granular structure.

[0041] Figure 5 The images shown are SEM-EDS mappings of the Ni-Fe LDH prepared in the preferred embodiment 1. Wherein: a and b are the structural SEM images of the material itself, and c, d, and e are the SEM-EDS mappings of Ni-Fe LDH, corresponding to elements C, Ni, and Fe, respectively.

[0042] Figure 6 The attached diagrams and pore size distributions show the N2 adsorption and desorption of Ni-Fe LDH, Co-Fe LDH, Cu-Fe LDH and Mg-Fe LDH prepared in Examples 1 and 7-9.

[0043] Figure 7 XPS spectra of Ni-Fe LDH, Co-Fe LDH, Cu-Fe LDH and Mg-Fe LDH prepared in Examples 1 and 7-9.

[0044] Figure 8 FT-IR spectra of Ni-Fe LDH, Co-Fe LDH, Cu-Fe LDH and Mg-Fe LDH prepared in Examples 1 and 7-9.

[0045] Figure 9 Thermogravimetric temperature curves of Ni-Fe LDH, Co-Fe LDH, Cu-Fe LDH and Mg-Fe LDH prepared in Examples 1 and 7-9.

[0046] Figure 10 The results of microcalorimetry tests are shown for the Ni-Fe LDH / PPA composites with TPU prepared in Example 10 at different ratios; the material with an addition of 3 wt% has the lowest peak heat release, and an addition of 3 wt% is preferred for testing and research.

[0047] Figure 11 The results of cone calorimeter tests at 35 kW are shown for the Ni-Fe LDH, Co-Fe LDH, Cu-Fe LDH and Mg-FeLDH composites prepared in Examples 1 and 7-9 with TPU. a is the heat release rate curve of the material, b is the total heat release curve, c is the flue gas release rate curve, d is the total flue gas release curve, e is the CO generation rate curve, and f is the CO2 generation rate curve. The addition of Ni-Fe LDH has the best effect, with the highest reduction in peak heat release of 21.4% and the highest reduction in total heat release of 36.8%. Ni-Fe LDH is preferred for organic acid intercalation studies.

[0048] Figure 12 This is a diagram showing the predicted reaction pathways for the decomposition of organophosphates.

[0049] Figure 13 The attached diagram shows the N2 adsorption and desorption of Ni-Fe LDH / PPA and Ni-Fe LDH / DPA prepared in Examples 10 and 11.

[0050] Figure 14 FT-IR spectra of Ni-Fe LDH / PPA and Ni-Fe LDH / DPA prepared in Examples 10 and 11.

[0051] Figure 15 The results of cone calorimetry tests at 35 kW are shown for the Ni-Fe LDH / PPA and Ni-Fe LDH / DPA composites with TPU prepared in Examples 10 and 11. a is the heat release rate curve, b is the total heat release curve, c is the flue gas release rate curve, d is the total flue gas release curve, e is the CO generation rate curve, and f is the CO2 generation rate curve. After organic acid intercalation in Ni-Fe LDH, the heat release and smoke release of the composite material are further reduced. The Ni-Fe LDH / PPA / TPU showed the highest effect, with a maximum reduction of 38.58% in peak heat release and a maximum reduction of 38.78% in total smoke release, indicating that the organic acid intercalation with PPA further improved the fire safety performance of the material.

[0052] Figure 16The combustion smoke density test results of the Ni-Fe LDH / PPA and Ni-Fe LDH / DPA composites prepared in Examples 10 and 11 after being combined with TPU are shown at 25kW. a) is the smoke density curve of the material, b) is a bar graph of the maximum smoke release, and c) is a bar graph of the time to reach the maximum smoke release. Before intercalation, the addition of Ni-Fe LDH reduced the smoke density of the material to a certain extent, by 10.6%. After intercalation, the smoke density of the composite material decreased significantly. The intercalation effect of DPA was the best, significantly reducing the smoke density of the composite material (63.9%), demonstrating the excellent smoke suppression effect of Ni-Fe LDH / DPA on TPU materials.

[0053] Figure 17 Scanning electron microscope (SEM) images of the char residue after combustion of the Ni-Fe LDH / PPA and Ni-Fe LDH / DPA composites with TPU prepared in Examples 10 and 11. a, b, and c are SEM images of the char residue after TPU combustion; the char residue is loose and fragmented. c, d, and e are SEM images of the char residue after Ni-Fe LDH / TPU combustion; the char residue is more dense. g, h, and i are SEM images of the char residue after Ni-Fe LDH / PPA / TPU combustion; the char residue becomes loose and intact. j, k, and l are SEM images of the char residue after Ni-Fe LDH / DPA / TPU combustion; the char residue becomes loose and intact. The looseness of the material demonstrates that the intercalated Ni-Fe LDH has an inhibitory effect on the combustion of TPU. The loose and intact char layer is beneficial for inhibiting the combustion of the material and provides a certain barrier effect.

[0054] Figure 18 The tensile properties of the Ni-Fe LDH / PPA and Ni-Fe LDH / DPA composites prepared in Examples 10 and 11, after being combined with TPU, are shown in graphs. a represents the tensile properties, b represents the maximum tensile strength, and c represents the elongation at break. The addition of Ni-Fe LDH significantly reduces the mechanical properties of TPU due to its uneven distribution. However, after intercalation of Ni-Fe LDH with organic acid radicals, the presence of organic ions optimizes the interfacial properties of the material through organic-inorganic interactions, resulting in a certain degree of improvement in the mechanical properties of TPU. Detailed Implementation

[0055] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0056] Unless otherwise shown or indicated in the operational embodiments, all figures used to represent the amounts, physicochemical properties, etc., of ingredients in the specification and claims are to be understood to be adjusted by the term "about" in all cases. Therefore, unless stated to the contrary, the numerical parameters listed in the foregoing specification and appended claims are approximations, and those skilled in the art can appropriately modify these approximations to obtain the desired characteristics by utilizing the teachings disclosed herein. The use of numerical ranges indicated by endpoints includes all numbers within that range and any range within that range; for example, 1 to 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4, and 5, etc.

[0057] In the experiment, the present invention first prepared layered metal hydroxides by hydrothermal method and coprecipitation method. By comparing and optimizing the morphology of different methods, suitable reaction methods and reaction conditions were selected, and then organophosphates were further intercalated in situ.

[0058] Specifically, the steps include the following:

[0059] S1. Layered metal hydroxides were prepared by combining co-precipitation and hydrothermal methods;

[0060] S11. Select different preparation methods (coprecipitation method and hydrothermal method) to prepare LDH. For the hydrothermal method, triethanolamine or urea is selected as the precipitant, and for the coprecipitation method, sodium carbonate is selected as the precipitant.

[0061] S12. The hydrothermal preparation method is as follows: Nickel chloride and ferric chloride (the molar ratio of divalent metal salt to trivalent metal salt in the active metal component is 2:1-3:1, and the total metal salt content is 0.1-0.2 mol) are mixed and dissolved in deionized water; triethanolamine aqueous solution is added to the aqueous solution of the metal precursor as a hydrothermal precipitant, and the mixture is stirred continuously at a temperature range of 25-30℃ to ensure uniform mixing; for example, the amount of nickel chloride is 0.09 mol and the amount of ferric chloride is 0.06 mol.

[0062] S13. Transfer the above suspension to a high-pressure reactor and carry out a hydrothermal reaction at 100℃-150℃. Filter to obtain the precipitate, wash with ethanol and deionized water, collect the precipitate, and dry it in a forced-air oven to obtain Ni-Fe LDH.

[0063] S14. The preparation method of coprecipitation is as follows: Nickel chloride and ferric chloride (the molar ratio of divalent metal salt to trivalent metal salt in the active metal component is 2:1-3:1, and the total metal salt content is 0.1-0.2 mol) are mixed and dissolved in deionized water. The mixture is stirred continuously at a temperature range of 25-30℃ to ensure uniform mixing. A sodium carbonate aqueous solution is added as the precipitant in the metal precursor aqueous solution (the concentration of sodium carbonate solution is 0.5-1 mol / L), with a dropping rate of 1 d / s, until the pH of the suspension reaches 10. The mixture is stirred continuously at a temperature range of 25-30℃, and the pH of the suspension is kept stable for 1-2 hours. The precipitate is obtained by filtration, washed with ethanol and deionized water, and collected. The precipitate is then dried in a forced-air drying oven to obtain Ni-FeLDH. For example, the nickel chloride content is 0.8 mol, the ferric chloride content is 0.6 mol, and the concentration of the sodium carbonate solution is 1 mol / L.

[0064] The preparation methods of S15, Mg-Fe LDH, Co-Fe LDH, Cu-Fe LDH and Ni-Fe LDH are similar, but the metals selected are different. Mg-Fe LDH selects Mg and Fe; Co-Fe LDH selects Co and Fe; Cu-Fe LDH selects Cu and Fe.

[0065] S2. In-situ intercalation of LDH with phosphorus-containing organic acids was performed to obtain LDH with organic acid anions.

[0066] S21. The organophosphate group selected by phenylphosphine (PPA) or diphenylphosphine (DPA) will perform in-situ intercalation of layered metal hydroxides prepared by hydrothermal method.

[0067] S22. Mix nickel chloride and ferric chloride (the molar ratio of divalent to trivalent metal salt in the active metal component is 2:1-3:1, and the total metal salt content is 0.1-0.2 mol) and dissolve them in deionized water; add an aqueous solution containing organic phosphoric acid, phenylphosphine (PPA), and triethanolamine as a hydrothermal precipitant to the aqueous solution of the metal precursor, and continuously stir to mix evenly within a temperature range of 25-30°C; for example, the amount of nickel chloride is 0.8 mol, the amount of ferric chloride is 0.6 mol, and the amount of phenylphosphine is 0.6 mol.

[0068] S23. Transfer the above suspension to a high-pressure reactor and carry out a hydrothermal reaction at 100℃-150℃. Filter to obtain the precipitate, wash with ethanol and deionized water, collect the precipitate, and dry it in a forced-air oven to obtain Ni-Fe / PPA LDH.

[0069] The preparation methods of S24, DPA-intercalated Ni-Fe-LDH and PPA-intercalated Ni-Fe-LDH are similar. The selected organophosphate is replaced by diphenylphosphine (DPA) to prepare DPA-intercalated Ni-Fe-LDH, denoted as Ni-Fe / DPA LDH.

[0070] The following examples describe the disclosure of this invention in more detail. These examples are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of this disclosure. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are based on weight, and all reagents used in the examples are commercially available or synthesized by conventional methods and can be used directly without further processing. The instruments used in the examples are also commercially available.

[0071] Example 1:

[0072] Layered metal hydroxides (LDHs) are prepared by selecting chloride salts of different metal precursors. Taking the hydrothermal preparation of Ni-FeLDH as an example, the metal salt precursors include nickel hexahydrate and nickel chloride nonahydrate and ferric chloride.

[0073] 1. Mix nickel chloride hexahydrate and nickel chloride nonahydrate in a defined ratio (the molar ratio of nickel chloride to ferric chloride in the active metal cation components is 2:1, and the total metal salt content is 0.15 mol), dissolve in 200 ml of deionized water, and stir continuously at 300 rpm for 1 hour at a temperature of 25°C until homogeneous. This mixed solution is denoted as solution A.

[0074] 2. Dissolve 15g of triethanolamine in 100ml of deionized water, stirring at 300rpm, at 25℃, for 0.5h. Label this mixture as solution B.

[0075] 3. Slowly add solution B to solution A and mix while stirring at 300 rpm at 25°C for 1 hour. Transfer the mixture to a Teflon-lined stainless steel high-pressure reactor and perform a hydrothermal reaction at 110°C for 12 hours. After the hydrothermal reaction, collect the precipitate by centrifugation, wash with ethanol and deionized water until the pH is approximately 7, centrifuge at 6000 rpm for 5 minutes, collect the precipitate, and dry it in a forced-air oven at 60°C for 12 hours. Ni-Fe LDH is obtained.

[0076] Example 2:

[0077] Example 2 is essentially the same as Example 1, the main difference being the hydrothermal precipitant. In Example 2, urea is used instead of precipitant, and the synthesis is carried out by adjusting the precipitant according to the stoichiometric ratio. The metal salt precursors include cobalt hexahydrate and ferric chloride nonahydrate. Ni-Fe LDH is prepared.

[0078] Example 3:

[0079] Ni-Fe LDH was prepared by coprecipitation, with metal salt precursors including nickel hexahydrate and nickel chloride nonahydrate and ferric chloride. Sodium carbonate was chosen as the precipitant for coprecipitation.

[0080] 1. Mix nickel chloride hexahydrate and nickel chloride nonahydrate in a defined ratio (the molar ratio of nickel chloride to ferric chloride in the active metal cation components is 2:1, and the total metal salt content is 0.15 mol), dissolve in 200 ml of deionized water, and stir continuously at 300 rpm for 1 hour at a temperature of 25°C until homogeneous. This mixed solution is denoted as solution A.

[0081] 2. Dissolve sodium carbonate in deionized water at a stirring speed of 300 rpm, a stirring temperature of 25℃, and a stirring time of 0.5 h. The concentration of the sodium carbonate solution is 1 mol / L. Label this mixture as solution B.

[0082] 3. Slowly add solution B to solution A to initiate a coprecipitation reaction at a dropping rate of 1 drop / s until the pH of the suspension reaches 10. Maintain a stirring speed of 300 rpm and a stirring temperature of 25°C, keeping the pH of the suspension stable, and stir for 2 hours. Filter to obtain the precipitate, wash with ethanol and deionized water until the pH of the filtrate is approximately 7, and collect the precipitate. Mix the precipitate thoroughly with 10 ml of deionized water. Pre-freeze the suspension at -40°C for 12 hours. Then, freeze-dry the frozen suspension in a freeze dryer for 48 hours at a vacuum degree of 10. -3 Pa was used to prepare Ni-Fe LDH.

[0083] Example 4:

[0084] Example 4 is basically the same as Example 3, the main difference being the drying method of the coprecipitation method. The drying method of the precipitate prepared by coprecipitation is changed from freeze drying to oven drying. The precipitate is placed in a forced-air oven and dried for 12 hours at a temperature of 60°C. Ni-Fe LDH is obtained.

[0085] Example 5:

[0086] Example 5 is essentially the same as Example 1, with the main difference being the ratio of the metal salt precursor reactants. The ratio of the metal salt precursor was changed from 2:1 to 3:1, 1:1, 1:2, 1:3, and 1:4, and the synthesis was carried out by changing the metal salt ratio according to the stoichiometric ratio. The metal salt precursors included cobalt chloride hexahydrate and ferric chloride nonahydrate. Ni-Fe LDH with different reactant ratios was prepared.

[0087] Example 6:

[0088] Example 6 is essentially the same as Example 1, with the main difference being the hydrothermal reaction temperature, which is 60℃, 90℃, 110℃, and 130℃, respectively, while the hydrothermal reaction time is the same. The metal salt precursors include hexahydrate and cobalt chloride, and nonahydrate and ferric chloride. Ni-Fe LDH with different reactant ratios were prepared.

[0089] Example 7:

[0090] Example 7 is essentially the same as Example 1, the main difference being the metal salt precursors. Synthesis was achieved by altering the metal salts according to their stoichiometric ratios. The metal salt precursors included cobalt chloride hexahydrate and ferric chloride nonahydrate. Co-Fe LDH was prepared.

[0091] Example 8:

[0092] Example 8 is essentially the same as Example 1, the main difference being the metal salt precursor. Synthesis was achieved by altering the metal salt according to its stoichiometric ratio. The metal salt precursors included dihydrate and copper chloride, and nonahydrate and ferric chloride. Cu-Fe LDH was prepared.

[0093] Example 9:

[0094] Example 9 is essentially the same as Example 1, the main difference being the metal salt precursors. Synthesis was achieved by altering the metal salts according to their stoichiometric ratios. The metal salt precursors included magnesium chloride hexahydrate and ferric chloride nonahydrate. Mg-Fe LDH was prepared.

[0095] Example 10:

[0096] Phosphorus-containing organic acid anions were selected for intercalation of Ni-Fe LDH to maintain high flame retardancy and tensile properties. In-situ intercalation experiments were conducted using phenylphosphine (PPA) for Ni-Fe LDH. Metal salt precursors included nickel hexahydrate and nickel chloride nonahydrate and ferric chloride.

[0097] 1. Mix nickel chloride hexahydrate and nickel chloride nonahydrate in a defined ratio (the molar ratio of nickel chloride to ferric chloride in the active metal cation components is 2:1, and the total metal salt content is 0.15 mol), dissolve in 200 ml of deionized water, and stir continuously at 300 rpm for 1 hour at a temperature of 25°C until homogeneous. This mixed solution is denoted as solution A.

[0098] 2. Dissolve 15g of triethanolamine in 100ml of deionized water, add phenylphosphine (PPA) (the molar ratio of phenylphosphine to LDH metal is 0.5-2), stir at 300rpm, at 25℃, for 1h. Label this mixture as solution B.

[0099] 3. Slowly add solution B to solution A and mix while stirring at 300 rpm at 25°C for 1 hour. Transfer the mixture to a Teflon-lined stainless steel high-pressure reactor and perform a hydrothermal reaction at 110°C for 12 hours. After the hydrothermal reaction, collect the precipitate by centrifugation, wash with ethanol and deionized water until the pH is approximately 7, centrifuge at 6000 rpm for 5 minutes, collect the precipitate, and dry it in a forced-air oven at 60°C for 12 hours. This yields PPA intercalated Ni-Fe LDH, denoted as Ni-Fe LDH / PPA.

[0100] Example 11:

[0101] Example 11 is basically the same as Example 10, the main difference being the phosphorus-containing organic acid. Diphenylphosphoric acid (DPA) was selected for in-situ intercalation experiments on Ni-Fe LDH. The metal salt precursors included nickel chloride hexahydrate and nickel chloride nonahydrate and ferric chloride. DPA-intercalated Ni-Fe LDH was obtained, denoted as Ni-Fe LDH / DPA.

[0102] Experimental Example 1:

[0103] The morphology of the Ni-Fe LDH prepared in Examples 1-6 was analyzed by scanning electron microscopy. The morphology of Ni-Fe LDH prepared by different methods differed. (See attached text.) Figure 1As shown. In Example 1, the Ni-Fe LDH prepared using triethanolamine as a hydrothermal precipitant exhibits a stacked lamellar structure with dimensions ranging from 20 to 50 nm. In Example 2, the Ni-Fe LDH prepared using urea as a hydrothermal precipitant exhibits a stacked whisker structure with dimensions ranging from 500 nm to 1 μm. In Example 3, the Ni-Fe LDH prepared by co-precipitation and freeze-drying exhibits a stacked rod-like structure with dimensions ranging from 1 μm to 5 μm. In Example 4, the Ni-Fe LDH prepared by co-precipitation and oven drying exhibits a stacked granular structure with dimensions ranging from 50 nm to 100 nm. It is preferred that the Ni-Fe LDH prepared using triethanolamine as a hydrothermal precipitant in Example 1 be used in subsequent experiments, as the stacked lamellar structure represents the optimized structure of LDH.

[0104] The Ni-Fe LDH prepared from reactants with different proportions in Example 5 had different structures; see [link to example]. Figure 2 As shown, when Ni:Fe is 2:1, the material has a layered structure; when Ni:Fe is 3:1, the small layers of the material are largely bonded together; when the proportion of Fe increases, the material gradually becomes spherical; when Ni:Fe is 1:4, the material has an independent spherical structure. The preferred reactant ratio Ni:Fe is 2:1 for subsequent experiments to ensure the layered structure of LDH.

[0105] The Ni-Fe LDH prepared at different hydrothermal reaction temperatures in Example 6 have different structures, see [link to example]. Figure 3 As shown, when the hydrothermal temperature is 60℃, the sample has a small lamellar structure; when the hydrothermal temperature is 90℃, the sample has a small lamellar structure; when the hydrothermal temperature is 110℃, the sample has a stacked large lamellar structure; and when the hydrothermal temperature is 130℃, the sample has a rod-like structure. Subsequent experiments are preferably conducted at a hydrothermal temperature of 110℃ to ensure the lamellar structure of the LDH.

[0106] Experimental Example 2:

[0107] The preferred Ni-Fe LDH prepared in Example 1 was analyzed by thermogravimetric analysis and scanning electron microscopy, see [link to relevant documentation]. Figure 4 and Figure 5As shown. The Ni-Fe LDH prepared in Example 1 exhibits multiple thermogravimetric peaks, corresponding to the removal of adsorbed H2O, the removal of interlayer CO2, the removal of interlayer H2O, and the formation of metal oxides. The weight loss peak of Ni-Fe LDH at around 100℃ corresponds to the removal of adsorbed H2O; as can be seen from the SEM image, the material still has a small lamellar structure. The weight loss peak of Ni-Fe LDH at around 300℃-380℃ corresponds to the removal of interlayer CO2; as can be seen from the SEM image, the small lamellars of the material gradually aggregate to form larger lamellar structures. The weight loss peak of Ni-Fe LDH at around 380℃-460℃ corresponds to the removal of interlayer H2O; as can be seen from the SEM image, the material begins to form metal oxides, and metal particles are generated on the layer surface. With further increases in temperature, layer rupture begins to occur, generating aggregated metal particles.

[0108] The Ni-Fe LDH, Co-Fe LDH, Cu-Fe LDH, and Mg-Fe LDH prepared in Examples 1 and 7-9 were analyzed by thermogravimetric analysis, see [link to relevant documentation]. Figure 9 As shown, all four types of LDH exhibit multiple thermal weight loss peaks, corresponding to the removal of adsorbed H2O, the removal of interlayer CO2, the removal of interlayer H2O, and the formation of metal oxides.

[0109] Experimental Example 3:

[0110] The specific surface area and pore size distribution of the Ni-Fe LDH, Co-Fe LDH, Cu-Fe LDH, Mg-Fe LDH, Ni-Fe LDH / PPA, and Ni-Fe LDH / DPA synthesized in Examples 1, 7-9, and 10-11 were analyzed by N2 adsorption-desorption analysis. (See attached figures.) Figure 6 and Figure 12 As shown in the figure, the pore size distribution reveals that all four synthesized LDHs are mesoporous materials. The N2 adsorption-desorption curves all exhibit type IV hysteresis loops, while Ni-Fe LDH and Co-Fe LDH show type H4 hysteresis loops, corresponding to typical curves for layered materials with narrow pores. Cu-Fe LDH and Mg-Fe LDH show type H3 hysteresis loops, corresponding to pores generated within the particles. After organic acid intercalation, the hysteresis loops remain unchanged. The intercalated Ni-Fe LDH exhibits type H4 hysteresis loops, corresponding to typical curves for layered materials with narrow pores, indicating that the pore structure of the material remains unchanged after intercalation.

[0111] Experimental Example 4:

[0112] XPS analysis was performed on the composition of the Ni-Fe LDH, Co-Fe LDH, Cu-Fe LDH, and Mg-Fe LDH prepared in Examples 1 and 7-9. (See attached text.) Figure 7As shown, in the four synthesized LDHs, the elements of the materials were all matched one-to-one, and different metal elements were detected.

[0113] Experimental Example 5:

[0114] The composition of the Ni-Fe LDH, Co-Fe LDH, Cu-Fe LDH, Mg-Fe LDH, Ni-Fe LDH / PPA, and Ni-Fe LDH / DPA prepared in Examples 1, 7-9, and 10-11 was analyzed using FT-IR materials. (See attached text.) Figure 8 and Figure 14 As shown. Characteristic peaks of interlayer water, CO, and CH were detected in all four synthesized LDHs. The infrared spectrum of phenyl hypophosphite was very similar to that of diphenylphosphite, with the main characteristic peaks of phenyl phosphate including 1629.18, 1438.49, and 960.93 cm⁻¹. -1 Peaks, etc. After organic acid intercalation in LDH, the characteristic peak of phenyl phosphate appears in LDH; it can also be seen that the P=O peak position of diphenyl phosphate red-shifts after losing a proton, indicating that diphenyl phosphate ions successfully enter the interlayer.

[0115] Experimental Example 6:

[0116] The decomposition reaction pathway prediction and analysis diagram of organophosphates is presented. Molecular simulations of diphenyl phosphate and phenyl hypophosphite were performed using Materials Studio software, and the results are as follows: Figure 12 As shown, the total reaction ΔG for diphenyl phosphate is 1456.72 kJ·mol⁻¹. -1 The reaction generates PO2· radicals, phenyl radicals, and phenyl anions. The total reaction ΔG for phenyl hypophosphite is 1470.19 kJ·mol⁻¹. -1 The reaction generates PO2· radicals, hydrogen radicals, and phenyl anions. During the decomposition of phenyl hypophosphite, hydrogen radicals may promote the combustion reaction of phenyl hypophosphite before the formation of PO2· radicals. This makes the flame retardancy of diphenyl phosphate-intercalated LDHs designed with PO2· as the flame retardant active ingredient stronger than that of phenyl hypophosphite-intercalated LDHs. When phenyl hypophosphite-intercalated LDHs are used as fillers, they may promote polymer decomposition to some extent, accelerating the combustion reaction. That is, although it does not affect the decomposition process of the organic polymer itself, hydrogen radicals diffuse into the combustion system and are easily oxidized, thus intensifying combustion. After the decomposition of diphenyl phosphate, phenyl groups are released, which are relatively more stable free radicals than hydrogen. In the presence of PO2·, they are likely to combine with other chain radicals to form aromatic fused ring structures, or directly act as carbon nuclei to undergo char formation, predicting that they will have a better flame retardant effect.

[0117] Experimental Example 7:

[0118] The aforementioned smoke-suppressing and toxicity-reducing hybrid material is added as an additive to thermoplastic polyurethane. The composite material is constructed using a melt blending method. After drying the TPU masterbatch, it is melted in an internal mixer, and then LDH smoke suppressant is added to mix evenly to obtain the TPU composite material. The composite material is then hot-pressed on a flat vulcanizing machine to obtain regular sheets.

[0119] (1) Dry the TPU masterbatch in an oven for 6 hours to remove moisture and set aside for use;

[0120] (2) The dried TPU masterbatch is melted in a mixer at a temperature of 180°C and a speed of 140 rpm. After the TPU is melted, the prepared LDH smoke suppressant is added to the mixer under stirring conditions. The amount of smoke suppressant added is 3wt%. The mixture is stirred for 5 minutes to mix evenly. Then the TPU composite material can be obtained.

[0121] (3) The obtained irregular TPU composite material is hot-pressed to obtain a regular sheet. The specific material size and standard are determined according to the national standard for combustion test. The hot-pressing process is carried out on a flat vulcanizing machine. The hot-pressing temperature is 185℃, the pressure is 10 MPa, the preheating time is 3-5 min, and the hot-pressing time is 1-3 min.

[0122] The smoke suppressant materials were selected from Ni-Fe LDH, Co-Fe LDH, Cu-Fe LDH, Mg-Fe LDH, Ni-Fe LDH / PPA, and Ni-Fe LDH / DPA prepared in Examples 1, 7-9, and 10-11, respectively. Based on the different smoke suppressant materials, the resulting composite materials were named Ni-Fe LDH / TPU, Co-Fe LDH / TPU, Cu-Fe LDH / TPU, Mg-Fe LDH / TPU, Ni-Fe LDH / PPA / TPU, and Ni-Fe LDH / DPA / TPU.

[0123] The heat release rate, total heat release, smoke release rate, and total smoke release of the prepared flame-retardant TPU composite materials (Ni-Fe LDH / TPU, Co-Fe LDH / TPU, Cu-Fe LDH / TPU, Mg-Fe LDH / TPU, Ni-Fe LDH / PPA / TPU, and Ni-Fe LDH / DPA / TPU) and the TPU materials were tested using a cone calorimeter at 35 kW. (See attached data.) Figure 11 and Figure 15As shown, the effects of different smoke suppressants on the combustion process of TPU materials are illustrated. First, the materials prepared in Examples 1 and 7-9, after being combined with TPU, were analyzed. The addition of Ni-Fe LDH showed the best effect, reducing peak heat release by up to 21.4% and total heat release by up to 36.8%. Therefore, Ni-Fe LDH was selected for organic acid intercalation studies.

[0124] After intercalation with organic acids in Ni-Fe LDH, the heat release and smoke release of the composite material were further reduced. Among them, Ni-Fe LDH / PPA / TPU showed the highest effect, with the peak heat release reduced by up to 38.58% and the total smoke release reduced by up to 38.78%, indicating that the intercalation with organic acids and PPA further improved the fire safety performance of the material.

[0125] Experimental Example 8:

[0126] The smoke density of the flame-retardant TPU composites (Ni-Fe LDH / TPU, Ni-Fe LDH / PPA / TPU, and Ni-Fe LDH / DPA / TPU) prepared in Experimental Example 7 was tested during combustion at 25 kW. (See attached data.) Figure 16 As shown, before intercalation, the addition of Ni-Fe LDH reduced the smoke density of the material to a certain extent, by 10.6%; after intercalation, the smoke density of the composite material was significantly reduced, with DPA showing the best intercalation effect, greatly reducing the smoke density of the composite material (63.9%), demonstrating the excellent smoke suppression effect of Ni-Fe LDH / DPA on TPU materials.

[0127] Experimental Example 9:

[0128] Scanning electron microscopy (SEM) tests were performed on the flame-retardant TPU composite materials (Ni-Fe LDH / TPU, Ni-Fe LDH / PPA / TPU, and Ni-Fe LDH / DPA / TPU) prepared in Experimental Example 7, as well as on the char residue after TPU material combustion. (See attached image.) Figure 17 As shown in the figure, the char residue after TPU combustion is loose and fragmented, while the char residue becomes denser after adding Ni-Fe LDH. After organic acid intercalation of Ni-Fe LDH, the char residue becomes loose and intact. The looseness of the material demonstrates that the intercalated Ni-Fe LDH has an inhibitory effect on TPU combustion. The loose and intact char layer is beneficial for inhibiting material combustion and provides a certain barrier effect.

[0129] Experimental Example 10:

[0130] Tensile tests were performed on the flame-retardant TPU composites (Ni-Fe LDH / TPU, Ni-Fe LDH / PPA / TPU, and Ni-Fe LDH / DPA / TPU) prepared in Experimental Example 7, as well as on the TPU material. See [link to relevant documentation]. Figure 18 As shown, the addition of Ni-Fe LDH significantly reduces the mechanical properties of TPU due to uneven material distribution. However, after organic acid intercalation of Ni-Fe LDH, the presence of organic ions optimizes the interfacial properties of the material through organic-inorganic interactions, resulting in a certain degree of improvement in the mechanical properties of TPU. Organic acid intercalation of LDH can achieve high flame retardancy and tensile strength retention even with high filler content.

[0131] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing an organophosphate intercalated layered metal hydroxide flame-retardant and smoke-suppressing hybrid material, comprising a hydrothermal in-situ intercalation method, characterized in that... Includes the following steps: Step 1: Mix the divalent metal salt and trivalent metal salt and dissolve them in deionized water. Add the precipitant and organophosphate compound, and stir continuously at a temperature range of 25-30℃ to mix evenly and obtain a suspension. Step 2: Transfer the suspension obtained in Step 1 to a high-pressure reactor and carry out a hydrothermal reaction at 100℃-150℃. Filter to obtain the precipitate, wash with ethanol and deionized water, and dry to obtain the organophosphate intercalated LDH hybrid material. In step 1, the divalent metal in the divalent metal salt is Ni. 2+ Co 2+ Cu 2+ Mg 2+ One or more of the following, wherein the trivalent metal in the trivalent metal salt is Fe. 3+ The molar ratio of the divalent metal to the trivalent metal in the divalent and trivalent metal salts is 2:1 to 3:

1. The precipitant is triethanolamine, and the molar ratio of the precipitant to the metal salt is between 2:1 and 4:

1. The organophosphate compound is phenylphosphine or diphenylphosphine, and the molar ratio of organophosphate to metal salt is 1:

2.

2. An organophosphate intercalated layered metal hydroxide flame retardant and smoke-suppressing hybrid material, prepared according to the method described in claim 1.

3. The application of the organophosphate intercalated layered metal hydroxide flame-retardant and smoke-suppressing hybrid material according to claim 2, characterized in that: The organophosphate intercalated layered metal hydroxide is added to thermoplastic polyurethane as an additive to improve the flame retardant and smoke suppression properties of the material; the amount of the organophosphate intercalated LDH hybrid material added is 1-3 wt% of the total mass of the composite material.

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