Antimony molybdate nanosheet and preparation method therefor, and modified ABS resin and preparation method therefor and use thereof

Abstract

The present invention belongs to the technical field of flame-retardant materials. Provided are an antimony molybdate nanosheet and a preparation method therefor, and a modified ABS resin and a preparation method therefor and the use thereof. The preparation method for an antimony molybdate (Sb2MoO6) nanosheet comprises the following steps: mixing a cationic surfactant, an antimony salt, a molybdate and water, and subjecting the resulting mixture to a hydrothermal reaction, so as to obtain an antimony molybdate nanosheet. The provided Sb2MoO6 nanosheet has a good dispersibility and interfacial interaction in an ABS resin matrix, thereby improving the tensile strength of the ABS resin matrix. The results of the embodiments show that the PHRR of ABS / AM5 and the PHRR of ABS / AM10 are respectively 19.7% and 32.9% lower than that of ABS. The PSPR inhibition rates of ABS / AM5 and ABS / AM10 are 19.7% and 32.4%, respectively, thereby indicating that the Sb2MoO6 nanosheet has an inhibition effect on heat release and smoke release.

Description

Antimony molybdate nanosheets and their preparation method, a modified ABS resin and its preparation method and application Technical Field

[0001] This application belongs to the field of flame retardant materials technology, specifically relating to an antimony molybdate nanosheet and its preparation method, a modified ABS resin and its preparation method and application. Background Technology

[0002] In recent years, nanotechnology for flame retardancy has become a major research hotspot in the field of flame retardancy. Because nanocomposites not only improve flame retardant properties but also enhance other properties (such as mechanical properties) compared to traditional flame retardant materials, the application prospects of nanomaterials in flame retardancy are very promising. Nanoparticles such as nanoclay, carbon nanotubes (CNTs), layered double hydroxides, and graphene have attracted widespread attention due to their flame retardant and smoke-suppressing effects on acrylonitrile-butadiene-styrene (ABS).

[0003] Furthermore, as a synergistic flame retardant of nanoparticles, antimony oxide (Sb₂O₃) can significantly improve the flame retardant properties of composite materials. For example, Sb₂O₃ flame retardant synergistically brominated epoxy resin (BEO), zinc hydroxystannate (ZHS), and MMT (montmorillonite) flame retardant composite materials undergo catalytic crosslinking in the condensed phase, thereby improving thermal stability and residual carbon content. Simultaneously, it dilutes combustible volatile products and captures free radicals in the gas phase; the combined effect of the gas and condensed phases produces a flame retardant effect.

[0004] However, the above-mentioned materials have poor flame retardant and smoke suppression effects on ABS, such as in terms of heat and smoke release. Summary of the Invention

[0005] In view of this, the purpose of this application is to provide antimony molybdate nanosheets and their preparation method, a modified ABS resin and its preparation method and application. The antimony molybdate nanosheets provided in this application have good flame retardant properties and can effectively inhibit the rapid combustion of ABS resin matrix.

[0006] To achieve the above objectives, this application provides the following solution:

[0007] This application provides a method for preparing antimony molybdate nanosheets, comprising the following steps:

[0008] A cationic surfactant, antimony salt, molybdate, and water are mixed and subjected to a hydrothermal reaction to obtain the antimony molybdate nanosheets; the temperature of the hydrothermal reaction is 160–210 °C.

[0009] Preferably, the cationic surfactant comprises one or more of hexadecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, and hexadecylpyridinium chloride; the molar ratio of molybdenum in the cationic surfactant and the molybdate is (0.5-0.7):1.

[0010] Preferably, the antimony salt includes antimony trichloride and / or antimony nitrate; the molybdate includes one or more of sodium molybdate, ammonium molybdate, and potassium molybdate; and the molar ratio of antimony in the antimony salt to molybdate in the molybdate is 2:(1-1.2).

[0011] Preferably, the hydrothermal reaction time is 6 to 18 hours.

[0012] Preferably, the mixing of the cationic surfactant, antimony salt, molybdate, and water comprises: performing a first mixing ultrasonication on the cationic surfactant and water, and then adding the antimony salt and molybdate, followed by a second mixing ultrasonication.

[0013] This application provides antimony molybdate nanosheets prepared by the preparation method described above, wherein the diameter of the antimony molybdate nanosheets is ≤500nm.

[0014] This application provides a modified ABS resin, comprising an ABS resin matrix and antimony molybdate nanosheets dispersed in the ABS resin matrix; the antimony molybdate nanosheets are those described in the above-mentioned scheme.

[0015] Preferably, the mass of the antimony molybdate nanosheets is 1 to 10% of the mass of the modified ABS resin.

[0016] Preferably, the modified ABS resin has a tensile strength of 65-75 MPa and an elongation at break of 12-16.5%.

[0017] Preferably, the peak heat release rate of the modified ABS resin is 618–914 kW / m³. 2 The peak smoke release rate was 0.111–0.174 m. 2 / s.

[0018] This application provides a method for preparing the modified ABS resin described above, comprising the following steps:

[0019] The modified ABS resin is obtained by melt blending antimony molybdate nanosheets and ABS resin matrix.

[0020] Preferably, the melt blending temperature is 180–210°C and the time is 10–18 min.

[0021] The invention provides the application of the modified ABS resin described in the above-described scheme or the modified ABS resin prepared by the preparation method described in the above-described scheme in flame retardancy and smoke suppression.

[0022] This application provides a method for preparing antimony molybdate (Sb₂MoO₆) nanosheets, comprising the following steps: mixing a cationic surfactant, an antimony salt, a molybdate, and water, and carrying out a hydrothermal reaction to obtain the antimony molybdate nanosheets. The cationic surfactant in this application acts as a structure modifier for the nanoparticles, enabling antimony molybdate to form a unique nanosheet layer structure (mainly the cationic portion of the cationic surfactant regulates the dispersibility of the nanosheets, causing the antimony molybdate nanosheets to form a stacked structure). In flame retardancy, it blocks heat transfer during combustion, delaying the decomposition of the composite material; and prevents the diffusion of decomposition products into the gas phase.

[0023] This application provides a modified ABS resin, comprising an ABS resin matrix and antimony molybdate nanosheets dispersed in the ABS resin matrix. Due to the good dispersibility and interfacial interaction of the Sb₂MoO₆ nanosheets in the ABS resin matrix, this application improves the tensile strength of the ABS resin matrix. Example results show that the peak heat release rate (PHRR) of ABS / AM5 (representing 5% of the total mass of Sb₂MoO₆ and the ABS resin matrix) and ABS / AM10 (representing 10% of the total mass of Sb₂MoO₆ and the ABS resin matrix) is 19.7% and 32.9% lower than that of ABS, respectively. The inhibition rates of the peak smoke release rate (PSPR) of ABS / AM5 and ABS / AM10 are 19.7% and 32.4%, respectively, indicating that the Sb₂MoO₆ nanosheets have an inhibitory effect on heat release and smoke release.

[0024] The Sb₂MoO₆ nanosheets provided in this application have a good physical barrier effect in the condensed phase, which can protect the inner layer of ABS resin from further pyrolysis and combustion. The results of the examples show that the Sb₂MoO₆ nanosheets have good flame retardant properties and can effectively inhibit the rapid combustion of the ABS matrix. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 shows the XRD pattern (a) and SEM image (b) of the Sb2MoO6 sample of Comparative Example 1.

[0027] Figure 2 shows the Sb2MoO6 sample AM-6h(a) of Example 2, the Sb2MoO6 sample AM-9h(b) of Example 3, and the Sb2MoO6 sample AM-12h(c) of Example 1;

[0028] Figure 3 shows SEM images of Sb2MoO6 sample AM-15h(a) from Example 4 and Sb2MoO6 sample AM-18h(b) from Example 5.

[0029] Figure 4 shows the XRD patterns of Sb2MoO6 samples synthesized at different reaction times in Examples 1-5, and a comparison with the Sb2MoO6 database.

[0030] Figure 5 shows the XPS full spectrum of the Sb2MoO6 sample in Example 1 (a), Sb3d (b), O1s (d), and Mo3d (c) of the Sb2MoO6 sample in Example 1.

[0031] Figure 6 shows TEM images (a-d) of Sb2MoO6 in Example 1;

[0032] Figure 7 shows the STEM-HAADF diagram (a) of Sb2MoO6 in Example 1 and the elemental diagrams of Mo, Sb, and O in the corresponding regions (b-d);

[0033] Figure 8 shows ABS / AM1 (a1~a2) in Application Example 1 and ABS / AM5 (b1~b2) in Application Example 3;

[0034] Figure 9 shows the TEM images (a-b) of the ABS / AM10 in Application Example 4;

[0035] Figure 10 shows the XRD patterns of pure ABS and ABS composite materials;

[0036] Figure 11 shows the stress-strain curves (a) and mechanical property parameters (b) of the ABS / AM composite material;

[0037] Figure 12 shows the TG(a) and DTG(b) curves of the ABS / AM composite material of Application Examples 1-4, pure ABS, and the Sb2MoO6 sample of Example 1 (i.e. AM in Figure 12) in air atmosphere.

[0038] Figure 13 shows the heat release rate curves (a) and smoke generation rate curves (b) of ABS and ABS / AM samples in Application Examples 1-4;

[0039] Figure 14 shows SEM images of residual carbon from ABS / AM1 (a1-a2) and ABS / AM5 (b1-b2) composite materials;

[0040] Figure 15 shows the SEM images of residual carbon in the ABS / AM10 composite material (a-b);

[0041] Figure 16 shows the XPS full spectrum of the ABS / AM10 carbon residue from Application Example 4;

[0042] Figure 17 shows the O1s(a), Mo3d(b), C1s(c), and Sb3d(d) spectra of the ABS / AM10 char residue from Application Example 4.

[0043] Figure 18 shows the FTIR spectra of ABS and ABS composite carbon residues. Detailed Implementation

[0044] This application provides a method for preparing antimony molybdate nanosheets, comprising the following steps:

[0045] The antimony molybdate nanosheets were obtained by mixing a cationic surfactant, an antimony salt, a molybdate, and water and carrying out a hydrothermal reaction.

[0046] Unless otherwise specified, all materials and equipment used in this application are commercially available products.

[0047] In this application, the cationic surfactant preferably includes one or more of hexadecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, and hexadecylpyridinium chloride; the molar ratio of the cationic surfactant to molybdate is preferably (0.5-0.7):1, and in the embodiments of this application, it can specifically be 0.5:1, 0.55:1, 0.6:1, or 0.7:1. The cationic surfactant of this application acts as a structure modifier for nanoparticles, enabling antimony molybdate to form a unique nanosheet structure (mainly the cationic portion of the cationic surfactant regulates the dispersibility of the nanosheets, causing the antimony molybdate nanosheets to form a stacked structure). During flame retardancy, it blocks heat transfer during combustion, delays the decomposition of the composite material, and prevents the diffusion of decomposition products into the gas phase.

[0048] In this application, the antimony salt preferably includes antimony trichloride and / or antimony nitrate; the molybdate preferably includes one or more of sodium molybdate, ammonium molybdate and potassium molybdate; the molar ratio of antimony in the antimony salt to molybdate in the molybdate is preferably 2:(1 to 1.2), and in the embodiments of this application, it can specifically be 2:1 or 2:1.2.

[0049] In this application, the temperature of the hydrothermal reaction is 160-210°C. In the embodiments of this application, it can specifically be 160°C, 170°C, 180°C, 190°C, 200°C, or 210°C. The time of the hydrothermal reaction is preferably 6-18 hours. In the embodiments of this application, it can specifically be 6 hours, 8 hours, 9 hours, 10 hours, 12 hours, 15 hours, or 18 hours.

[0050] In this application, the mixing of cationic surfactant, antimony salt, molybdate and water preferably includes: performing a first mixing ultrasonication on cationic surfactant and water, then adding antimony salt and molybdate, and performing a second mixing ultrasonication.

[0051] In this application, the mass ratio of the cationic surfactant to the volume ratio of water is preferably 2.5 mg:1 mL. In this application, the second mixing ultrasound time is preferably 10 min. This application, through the first mixing ultrasound, enables the cationic surfactant to dissolve in water; this application, through the second mixing ultrasound, enables the antimony salt and molybdate to be uniformly dispersed in water.

[0052] After the hydrothermal reaction is completed, the present application preferably washes the resulting reaction solution with water and ethanol, then centrifuges to collect the precipitate, and then dries and grinds it to obtain the antimony molybdate nanosheets.

[0053] In this application, the drying temperature is preferably 60°C, and the drying time is preferably 12 hours.

[0054] This application provides antimony molybdate nanosheets prepared by the preparation method described above, wherein the diameter of the antimony molybdate nanosheets is ≤500nm.

[0055] This application provides a modified ABS resin, comprising an ABS resin matrix and antimony molybdate nanosheets dispersed in the ABS resin matrix; the antimony molybdate nanosheets are those described in the above-mentioned scheme. This application does not have any particular requirements for the ABS resin matrix; any matrix well-known in the art can be used.

[0056] In this application, the mass of the antimony molybdate nanosheets is preferably 1 to 10% of the mass of the modified ABS resin. In the embodiments of this application, it can specifically be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%.

[0057] In this application, the addition of Sb₂MoO₆ nanosheets promotes the carbonization of the modified ABS resin, thereby increasing the fire resistance of the ABS resin matrix. Simultaneously, with the addition of Sb₂MoO₆, the carbon structure becomes denser and more continuous; the formation of this dense carbon helps suppress heat release and smoke generation during combustion. The Sb₂MoO₆ nanosheets function in the condensed phase during combustion, thus improving the fire safety of the modified ABS resin.

[0058] This application provides a method for preparing modified ABS resin, comprising the following steps:

[0059] The modified ABS resin is obtained by melt blending antimony molybdate nanosheets and ABS resin matrix.

[0060] In this application, the melt blending temperature is preferably 180–210°C, and in specific embodiments, it can be 180°C, 190°C, 200°C, or 210°C; the melt blending time is preferably 10–18 minutes, and in specific embodiments, it can be 10 minutes, 12 minutes, 14 minutes, 15 minutes, or 18 minutes. In this application, the melt blending is preferably carried out under stirring conditions, and the stirring speed is preferably 60 rpm.

[0061] This application enables the uniform distribution of antimony molybdate nanosheets in an ABS resin matrix through melt blending.

[0062] This application provides the application of the modified ABS resin described in the above-described scheme or the modified ABS resin prepared by the above-described preparation method in flame retardancy and smoke suppression. Specifically, the modified ABS resin can be applied to electrical appliances, such as television casings or switch casings.

[0063] This application demonstrates that Sb₂MoO₆ nanosheets exhibit good dispersibility and interfacial interactions within the ABS resin matrix, thereby improving the tensile strength of the ABS resin matrix. Example results show that the peak heat release rate (PHRR) of ABS / AM5 (representing 5% of the total mass of Sb₂MoO₆ and ABS resin matrix) and ABS / AM10 (representing 10% of the total mass of Sb₂MoO₆ and ABS resin matrix) is 19.7% and 32.9% lower than that of ABS, respectively. The inhibition rates of the peak smoke release rate (PSPR) of ABS / AM5 and ABS / AM10 are 19.7% and 32.4%, respectively, indicating that Sb₂MoO₆ nanosheets have an inhibitory effect on heat release and smoke release.

[0064] The Sb₂MoO₆ nanosheets provided in this application have a good physical barrier effect in the condensed phase, which can protect the inner layer of ABS resin from further pyrolysis and combustion. The results of the examples show that the Sb₂MoO₆ nanosheets have good flame retardant properties and can effectively inhibit the rapid combustion of the ABS matrix.

[0065] To further illustrate this application, the following detailed descriptions, in conjunction with the accompanying drawings and embodiments, describe a type of antimony molybdate nanosheet and its preparation method, a modified ABS resin and its preparation method, and its applications. However, these descriptions should not be construed as limiting the scope of protection of this application.

[0066] The ABS resin used in the examples was purchased from Tianjin Dagu Chemical Co., Ltd.; cetyltrimethylammonium bromide (CTAB), antimony trichloride (SbCl3), sodium molybdate, and dihydrate (Na2MoO4·2H2O) were all purchased from Sinopharm Chemical Reagent Co., Ltd.; and anhydrous ethanol (C2H5OH) was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0067] Example 1

[0068] Sb₂MoO₆ nanostructures were synthesized via a hydrothermal method using CTAB as the cationic surfactant, SbCl₃ as the Sb source, and Na₂MoO₄·2H₂O as the Mo source. CTAB (200 mg) was dissolved in 80 mL of deionized water by sonication. Then, SbCl₃ (2 mmol) and Na₂MoO₄·2H₂O (1 mmol) were added to the solution, and the mixture was sonicated for 10 min to ensure uniform dispersion. The resulting green precursor solution was then transferred to a 100 mL high-pressure reactor and reacted in a 180 °C drying oven for 12 h. After the reactor cooled to room temperature, it was thoroughly washed with water and ethanol, and the green precipitate was collected by centrifugation. Finally, the precipitate was dried in a 60 °C drying oven for 12 h and ground to obtain the green powder product, Sb₂MoO₆ nanosheets, designated AM-12.

[0069] Examples 2-5

[0070] The preparation steps were the same as in Example 1, except that the reaction times were 6h, 9h, 15h and 18h, respectively, to obtain Sb2MoO6 nanosheets, which were designated as AM-6, AM-9, AM-15 and AM-18.

[0071] Comparative Example 1

[0072] The preparation steps were the same as in Example 1, except that CTAB was not added, resulting in the green powder product Sb2MoO6.

[0073] Application Example 1

[0074] The composite was pre-dispersed by melt blending using a Thermo Hakker rheometer (temperature: 200 °C, time: 15 min, rotor speed: 60 rpm).

[0075] Specifically, the Sb2MoO6 nanosheets prepared in Example 1 were mixed with the ABS resin matrix and melt-blended using a Thermo Hakker rheometer. The melt-blending temperature was 200°C, the time was 15 min, and the rotor speed was 60 rpm. The mass of the Sb2MoO6 nanosheets was 1.0% of the total mass of the Sb2MoO6 nanosheets and the ABS resin matrix, resulting in a modified ABS resin, denoted as ABS / AM1.

[0076] Application Examples 2-4

[0077] The preparation steps are the same as in Application Example 1, except that the mass of the Sb2MoO6 nanosheets is 3.0%, 5.0%, and 10.0% of the total mass of the Sb2MoO6 nanosheets and the ABS resin matrix, respectively, and are designated as ABS / AM3, ABS / AM5, and ABS / AM10.

[0078] Structural characterization and performance testing

[0079] The chemical structures of nanomaterials and char residues were analyzed using Fourier transform infrared spectroscopy (FTIR, Nicolet-5700, USA); the chemical structures of nanomaterials were analyzed using X-ray photoelectron spectroscopy (XPS, Kratos AXIS Ultra DLD, Japan); the morphology of samples was observed using scanning electron microscopy (SEM, Hitachi S-4800(II), Japan), transmission electron microscopy (TEM, JEM-1230), and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM, Tecnai G2 F30 S-TWIN), which was equipped with an energy-dispersive X-ray (EDX) spectrometer; and the chemical structures of nanoparticles and ABS nanocomposites were studied using X-ray diffraction (XRD, Bruker AXSD8 Advance, Germany).

[0080] The mechanical properties of the samples were tested using an AG-IS universal testing machine (ASTM D-638); the oxygen index (LOI) of the samples was determined using an oxygen index meter (PX-01-005, Phoenix, China) according to ASTM D2863; the combustion performance and smoke suppression performance of the samples were tested using a cone calorimeter (FTT, UK) according to ISO 5660-1; and the degree of graphitization of the carbon was studied using a Raman spectrometer (DXR2xi, Thermo Scientific, USA).

[0081] Structural characterization and performance testing of Sb2MoO6 nanosheets

[0082] Figure 1 shows the XRD pattern (a) and SEM image (b) of the Sb₂MoO₆ sample of Comparative Example 1. In Figure 1a, the product prepared without CTAB reaction for 12 h is shown. Figure 4 shows the X-ray diffraction (XRD) patterns of the products prepared with CTAB reaction for different times, all of which match well with the standard pattern of Sb₂MoO₆ (JCPDS 33-1491). No additional peaks were detected, indicating high product purity. With increasing reaction time, the intensity of the diffraction peaks initially increased and then decreased, with the strongest diffraction peak observed at AM-12h.

[0083] Figure 2 shows Sb2MoO6 samples AM-6h (a) of Example 2, AM-9h (b) of Example 3, and AM-12h (c) of Example 1; Figure 3 shows SEM images of Sb2MoO6 samples AM-15h (a) of Example 4 and AM-18h (b) of Example 5. Figures 2 and 3 clearly show that the Sb2MoO6 prepared with CTAB for different times exhibits a sheet-like morphology of varying sizes; while Figure 1b shows both sheet-like and granular morphologies. Based on XRD and SEM tests, and combined with actual experimental conditions, this application confirms that adding CTAB for 12 hours prepares Sb2MoO6 nanomaterials (all test samples below were prepared under these conditions).

[0084] Figure 4 shows the XRD patterns of Sb₂MoO₆ samples synthesized at different reaction times in Examples 1-5, compared with the JCPDS database for Sb₂MoO₆. Figure 5 shows the full XPS spectrum of the Sb₂MoO₆ sample from Example 1 (a), Sb₃d (b), O₁s (d), and Mo₃d (c) spectra of the Sb₂MoO₆ sample from Example 1. In Figure 5a, the X-ray photoelectron spectroscopy (XPS) spectrum of Sb₂MoO₆ is shown, and all data have been calibrated using C₁s (284.6 eV). Containing C, O, Mo, and Sb elements, this spectrum matches the spectra previously reported in the literature. In the high-resolution spectrum of Sb (Figure 5b), the peak at 539.4 eV can be attributed to Sb 3d 3 / 2. Due to the overlap between Sb 3d 5 / 2 and O1s, the broad peak centered at 530.1 eV can be divided into an Sb 3d 5 / 2 peak (from Sb metal and Sb oxide) and an O1s peak (from CO groups and the SEI in carbonate state). As shown in Figure 5d, the peaks at 232.3 and 235.4 eV are attributed to Mo 3d 5 / 2 and Mo 3d 3 / 2, respectively.

[0085] Figure 6 shows TEM images (a-d) of Sb₂MoO₆ from Example 1; Figure 7 shows STEM-HAADF images (a) and elemental maps (b-d) of Mo, Sb, and O in the corresponding regions of Sb₂MoO₆ from Example 1. Figure 6: The TEM images (a-c) further confirm the plate-like morphology of Sb₂MoO₆ particles. In the high-resolution TEM image (d) of Figure 6, lattice fringes on the (2-20) plane can be clearly observed with a spacing of 0.249 nm, further demonstrating the high crystallinity of Sb₂MoO₆ plates. Figure 7a shows the HAADF image of Sb₂MoO₆ nanosheets, and Figures 7b-c show the distribution of Sb, Mo, and O.

[0086] Structural characterization and performance testing of ABS composite materials (i.e., modified ABS resin)

[0087] The ABS composite materials prepared in Application Examples 1-4 were placed in a mold, preheated at 205°C for 6 min, and pressed at 12 MPa for 8 min to prepare thick sheets for subsequent testing.

[0088] Figure 8 shows ABS / AM1 (a1-a2) from Application Example 1 and ABS / AM5 (b1-b2) from Application Example 3; Figure 9 shows TEM images (a-b) of ABS / AM10 from Application Example 4; where the scale bars for a1, b1, and a are all 200 nm, and the scale bars for a2, b2, and b are all 1 μm; Figure 10 shows the XRD patterns of pure ABS and ABS composite materials; Figure 11 shows the stress-strain curve (a) and mechanical property parameter comparison diagram (b) of the ABS / AM composite material. Figures 8-9: The performance improvement of ABS composite materials depends on the dispersibility of nano-additives. The dispersion of Sb2MoO6 in the ABS matrix was studied using TEM. At different addition amounts (1, 5, and 10 wt%), Sb2MoO6 nanosheets can be uniformly dispersed in ABS. At higher magnifications (a2 and b2 in Figure 8, b in Figure 9), the sheet-like structure of Sb2MoO6 with a size of approximately 0-500 nm can be observed. No characteristic peaks of Sb₂MoO₆ were observed in the XRD pattern (Figure 10). Based on the TEM and XRD results, it can be reasonably concluded that Sb₂MoO₆ can be well dispersed in the ABS matrix using only a simple melt-mixing method.

[0089] Figure 11a and Figure 11b show the stress-strain curves and mechanical property parameters of pure ABS and ABS composite material, respectively. The specific data are summarized in Table 1.

[0090] Table 1 Comparison of stress-strain curves and mechanical property parameters of pure ABS and ABS composite materials

[0091] As shown in Table 1 and Figures 11a-b, the presence of Sb₂MoO₆ nanosheets increases the tensile strength of ABS but slightly reduces the elongation at break. Compared with pure ABS resin, the ABS composite blend with 10% Sb₂MoO₆ nanosheets exhibits an increase in tensile strength of approximately 13% and a decrease in elongation at break of approximately 34%. The significant increase in tensile strength is mainly due to the mechanical reinforcing effect of the uniformly distributed Sb₂MoO₆ nanosheets within the polymer matrix.

[0092] Thermal decomposition behavior of ABS composite materials

[0093] The thermal decomposition behavior of pure ABS, pure Sb2MoO6 (i.e. AM in Figure 12 and Table 2) and ABS composites under air conditions is shown in Figure 12, and the relevant data are summarized in Table 2.

[0094] Table 2 Thermogravimetric data of ABS / AM composite materials a T i and b T max These refer to the temperatures at which mass loss reaches 5 wt% and at which maximum thermal weight loss occurs, respectively.

[0095] ABS is a copolymer composed of three components that undergoes two-stage decomposition when burned in air. The first stage occurs between 400 and 500°C, and this stage can be considered as the disintegration of the B-phase double bond structure of ABS and the oxidation of relatively unstable functional groups such as -CN bonds. The second stage occurs between 500 and 600°C, and this stage involves the decomposition of the remaining benzene rings and saturated hydrocarbon molecular chains from the previous stage. As shown in Figure 12 and Table 2, pure ABS begins to degrade at 373°C and reaches its maximum degradation rate at 418°C. Pure Sb₂MoO₆ burns in air in three stages. The first stage occurs between 200 and 420°C, with oxidative decomposition on AM. The second stage occurs between 420 and 680°C, where the TG curve rebounds due to the oxides produced during combustion. The third stage occurs between 680 and 800°C, where oxidative decomposition continues with increasing temperature, and the TG curve decreases again. The addition of Sb₂MoO₆ has almost no effect on the initial decomposition temperature of the composite material. The addition of Sb₂MoO₆ promoted the carbonization of ABS composites, and the carbonization effect increased with increasing addition amount. For example, in an air environment at 600°C, the residual carbon content of the ABS / AM10 sample reached 10.02%. Furthermore, compared with other composites, the mass loss rate (MLRmax) of ABS / AM10 was at the lowest peak, further confirming that Sb₂MoO₆ can improve the carbonization effect, thereby increasing the fire resistance of the underlying matrix.

[0096] Fire resistance of ABS composite materials

[0097] Cone calorimetry (CCT) testing is commonly used to evaluate the combustion behavior of polymers exposed to constant heat radiation under realistic fire conditions. Figure 13 shows the heat release rate (HRR) and smoke generation rate (SPR) curves (b) for ABS and ABS / AM samples from Application Examples 1–4. Figure 13(a) and (b) show the HRR and SPR curves, with detailed data summarized in Table 3. ABS showed a rate of 938 kW / m³. 2 Peak heat release rate (PHRR) and 116 MJ / m 2The PHRR of ABS / AM1, ABS / AM5, and ABS / AM10 decreased to 898 kW / m³. 2 753kW / m 2 and 629kW / m 2 Compared to pure ABS, the THR was reduced by 4.26%, 19.7%, and 32.9%, respectively. The THR of ABS / AM1, ABS / AM5, and ABS / AM / 10 decreased to 115 MJ / m³. 2 111MJ / m 2 and 104 MJ / m 2 This indicates that Sb₂MoO₆ has a combustion-inhibiting effect. Furthermore, the average mass loss rate (AMLR) decreases with increasing Sb₂MoO₆ addition, suggesting that the mass loss behavior of the ABS / AM composite is suppressed to some extent, which can explain the significant increase in char residue in ABS / AM.

[0098] Dense smoke is a key factor contributing to casualties in fires, therefore smoke generation data is crucial in assessing the fire safety of materials. It can be seen that the addition of 5 wt% and 10 wt% Sb₂MoO₆ significantly reduced the peak smoke release rate (PSPR) of ABS / AM5 and ABS / AM10. The PSPR was reduced by 19.7% and 32.4% compared to ABS, ABS / AM5, and ABS / AM10, respectively. The total smoke production (TSP) of ABS, ABS / AM5, and ABS / AM10 was 16.96 m³ / s. 2 16.52m 2 and 16.44m 2 Therefore, adding Sb2MoO6 can reduce the smoke hazard of ABS / AM.

[0099] Table 3. Cone calorimeter test data for ABS and ABS / AM samples.

[0100] TTI a Ignition timing, PHRR a Peak heat release rate (THR) a Total heat release, AMLR a Average mass loss rate, PSPR a Peak smoke emission rate, TSP a Total smoke emissions.

[0101] Flame retardant mechanism

[0102] Table 4. EDX data of carbon residue in ABS composite materials.

[0103] Figure 14 shows SEM images of ABS / AM1 (a1-a2) and ABS / AM5 (b1-b2) composite carbon residues; Figure 15 shows SEM images (a-b) of ABS / AM10 composite carbon residues. Figure 16 shows the XPS full spectrum of ABS / AM10 carbon residues from Application Example 4; Figure 17 shows the O1s (a), Mo3d (b), C1s (c), and Sb3d (d) spectra of ABS / AM10 carbon residues from Application Example 4; Figure 18 shows the FTIR spectra of ABS and ABS composite carbon residues.

[0104] To analyze the condensed phase effect of Sb₂MoO₆, the cone calorimetric char residues of ABS and ABS / AM were studied using SEM-EDX (Figures 14-15, Table 4) and FTIR (Figure 18). ABS left only a very small amount of broken and brittle char after testing, further indicating its poor char-forming ability. With the addition of Sb₂MoO₆, the char structure became denser and more continuous. This dense char formation helps to suppress heat release and smoke generation during combustion. It is also noteworthy that the plate-like material is well dispersed in the char layer, as observed in the figures (a2 and b2 in Figure 14 and b in Figure 15). XPS results of the ABS / AM10 char residue (Figures 16-17) confirm that the plate-like material is Sb₂MoO₆ platelets. In all FTIR spectra, the absorption peaks of the OH and C=C bonds are located at 3440 cm⁻¹. -1 1600cm -1 In addition to the peaks mentioned above, at approximately 760 cm⁻¹, in the FTIR spectra of ABS / AM1, ABS / AM5, and ABS / AM10, there is also a peak at this location. -1 The peaks at these locations can be attributed to the Mo-O absorption peaks. These results further confirm that Sb₂MoO₆ sheets play a role in the condensed phase during combustion, thereby improving the fire safety of ABS nanocomposites.

[0105] Although the above embodiments have provided a detailed description of this application, they are only some embodiments of this application, not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of this application.

Claims

1. A method for preparing antimony molybdate nanosheets, characterized in that, Includes the following steps: A cationic surfactant, antimony salt, molybdate, and water are mixed and subjected to a hydrothermal reaction to obtain the antimony molybdate nanosheets; the temperature of the hydrothermal reaction is 160–210 °C.

2. The preparation method according to claim 1, characterized in that, The cationic surfactant includes one or more of hexadecyltrimethylammonium bromide, dodecyltrimethylammonium chloride, and hexadecylpyridinium chloride; the molar ratio of molybdenum in the cationic surfactant and the molybdate is (0.5-0.7):

1.

3. The preparation method according to claim 1, characterized in that, The antimony salt includes antimony trichloride and / or antimony nitrate; the molybdate includes one or more of sodium molybdate, ammonium molybdate, and potassium molybdate; the molar ratio of antimony in the antimony salt to molybdate in the molybdate is 2:(1-1.2).

4. The preparation method according to claim 1, 2 or 3, characterized in that, The hydrothermal reaction takes 6 to 18 hours.

5. The preparation method according to claim 1, 2 or 3, characterized in that, The process of mixing the cationic surfactant, antimony salt, molybdate, and water includes: performing a first mixing ultrasonication on the cationic surfactant and water, then adding the antimony salt and molybdate, and performing a second mixing ultrasonication.

6. The antimony molybdate nanosheets prepared by the preparation method according to any one of claims 1 to 5, characterized in that, The diameter of the antimony molybdate nanosheets is ≤500nm.

7. A modified ABS resin, characterized in that, It includes an ABS resin matrix and antimony molybdate nanosheets dispersed in the ABS resin matrix; the antimony molybdate nanosheets are the antimony molybdate nanosheets as described in claim 6.

8. The modified ABS resin according to claim 7, characterized in that, The mass of the antimony molybdate nanosheets is 1 to 10% of the mass of the modified ABS resin.

9. The modified ABS resin according to claim 7, characterized in that, The modified ABS resin has a tensile strength of 65-75 MPa and an elongation at break of 12-16.5%.

10. The modified ABS resin according to claim 7, characterized in that, The peak heat release rate of the modified ABS resin is 618–914 kW / m³. 2 The peak smoke release rate was 0.111–0.174 m. 2 / s.

11. A method for preparing the modified ABS resin according to any one of claims 7 to 10, characterized in that, Includes the following steps: The modified ABS resin is obtained by melt blending antimony molybdate nanosheets and ABS resin matrix.

12. The preparation method according to claim 11, characterized in that, The melt blending temperature is 180–210°C, and the time is 10–18 min.

13. The application of the modified ABS resin according to any one of claims 7 to 10 or the modified ABS resin prepared by the preparation method according to claim 11 or 12 in flame retardancy and smoke suppression.

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