A composite functional material based on antimony trioxide and a preparation method thereof

Abstract

This invention relates to the field of flame-retardant materials, specifically to a composite functional material based on antimony trioxide and its preparation method, comprising: an antimony trioxide core; a MOF (Metal-Oxide-Factory) interlayer; and a phosphorus-containing organosilicon shell. This invention successfully prepares a novel composite functional material with stable structure and excellent performance by constructing a three-layer core-shell structure of "antimony trioxide core - MOF interlayer - phosphorus-containing organosilicon shell" and employing a stepwise preparation strategy of "thioglycolic acid surface modification - in-situ growth of MOFs - free radical polymerization grafting." This material exhibits excellent technical effects in terms of flame retardant performance, compatibility, and mechanical property retention, providing a new approach and technical method for the development of high-performance flame-retardant functional materials.

Description

Technical Field

[0001] This invention relates to the field of flame retardant materials, specifically to a composite functional material based on antimony trioxide and its preparation method. Background Technology

[0002] Antimony trioxide, a commonly used inorganic flame retardant, has wide applications in polymer materials such as plastics, rubber, textiles, and coatings. Its flame-retardant mechanism primarily involves synergistic action with halogenated flame retardants during combustion to generate compounds such as antimony halides. These compounds capture free radicals during combustion, interrupting the chain reaction and promoting the formation of a char layer on the material surface, thus isolating oxygen and heat. However, with increasingly stringent requirements for the comprehensive performance of materials, traditional antimony trioxide flame retardants have gradually revealed the following problems: First, it has poor compatibility. Antimony trioxide, as an inorganic powder, has strong surface polarity and poor compatibility with polymer matrices. When added directly, it easily agglomerates, leading to a decrease in the material's mechanical properties, such as tensile strength and impact toughness. Simultaneously, due to weak interfacial bonding, flame retardants are prone to migration and precipitation during use, affecting the durability of the flame retardant effect and the material's appearance.

[0003] Secondly, the flame retardant efficiency needs to be improved. Antimony trioxide alone has low flame retardant efficiency and usually needs to be compounded with halogen-containing flame retardants to achieve a high-efficiency flame retardant effect. How to improve the flame retardant efficiency of antimony trioxide under halogen-free conditions, reduce its dosage, and simultaneously maintain or improve the mechanical properties of the material is currently a hot research topic and a challenge.

[0004] To overcome these shortcomings, researchers have explored various modification methods. For example, they have organically treated the surface of antimony trioxide with silane coupling agents and titanate coupling agents to improve its compatibility with the polymer matrix. However, the thickness of this single-layer organic coating is limited, and it is difficult to simultaneously achieve interfacial compatibility and flame retardant synergy.

[0005] Based on the above-mentioned technical problems, this invention proposes a composite functional material based on antimony trioxide. By designing a three-layer core-shell structure of "antimony trioxide core - MOF intermediate layer - phosphorus-containing organosilicon shell", the synergistic effect between each layer is utilized to solve the problems of poor compatibility and low flame retardant efficiency of antimony trioxide in the prior art. Summary of the Invention

[0006] Purpose of the invention: To address the above-mentioned technical problems, this invention proposes a composite functional material based on antimony trioxide and its preparation method.

[0007] The technical solution adopted is as follows: A composite functional material based on antimony trioxide, comprising: Antimony trioxide nuclei; MOF intermediate layer; Phosphorus-containing organosilicon shell.

[0008] The composite functional material described in this invention has a typical three-layer core-shell structure. The antimony trioxide core serves as the core flame-retardant component, providing the main flame-retardant activity. The MOF intermediate layer, through its porous structure and abundant metal active sites, not only achieves uniform coating of the core but also catalyzes char formation during combustion, forming a synergistic flame-retardant effect with antimony trioxide. The phosphorus-containing organosilicon shell, as the outermost layer, improves compatibility with the polymer matrix and further enhances flame-retardant performance through its phosphorus-containing components, forming an outer protective barrier. The synergistic effect of the three layers allows the material to achieve excellent flame-retardant effects with low addition amounts, while having minimal impact on the mechanical properties of the matrix material.

[0009] A method for preparing a composite functional material as described in claim 1, comprising: Step 1: Modify antimony trioxide with mercaptoacetic acid; Step 2: Dissolve 2-methylimidazole, 2-vinylimidazole and zinc salt in methanol, add antimony trioxide modified with thioglycolic acid obtained in Step 1, and prepare a dispersion after stirring, reaction and static crystallization. Step 3: Under nitrogen protection, vinyl DOPO and octavinyl-POSS are added to the dispersion obtained in step 2, and the polymerization reaction is carried out in the presence of a free radical initiator.

[0010] The preparation method of this invention is ingeniously designed, making full use of the chemical bonding and interfacial interactions between the layers.

[0011] Specifically, in step 1, antimony trioxide is modified with mercaptoacetic acid. The thiol groups of mercaptoacetic acid can form coordinate bonds with antimony atoms on the surface of antimony trioxide, thereby introducing carboxyl groups onto the nucleus surface. These carboxyl groups can enhance the hydrophilicity of the nucleus surface, providing a favorable interfacial environment for the subsequent growth of MOFs. On the other hand, the carboxyl groups can act as coordination sites, coordinating with subsequently added zinc ions, thereby inducing in-situ nucleation and growth of MOFs on the nucleus surface.

[0012] In step 2, the modified antimony trioxide was added to a methanol solution containing 2-methylimidazole, 2-vinylimidazole, and zinc salt. 2-Methylimidazole and 2-vinylimidazole, acting as mixed ligands, coordinate with zinc ions to self-assemble into MOF structures (ZIF-8 and its derivatives). Because carboxyl groups were pre-introduced onto the core surface, these carboxyl groups can coordinate with zinc ions, allowing MOFs to preferentially nucleate and grow on the core surface, forming a uniform and dense intermediate coating layer. The introduction of 2-vinylimidazole introduced polymerizable vinyl functional groups into the MOF layer. These vinyl functional groups are exposed on the surface of the MOF layer, providing reaction sites for the subsequent covalent bonding of the shell layer.

[0013] In step 3, vinyl DOPO and octavinyl-POSS (octavinylsilsesquioxane) are added to the dispersion containing MOF-coated particles, and a polymerization reaction is carried out in the presence of a free radical initiator. Vinyl DOPO and octavinyl-POSS are both vinyl-containing monomers. Under the action of the initiator, they undergo a free radical copolymerization reaction. Simultaneously, the polymerization reaction also grafts onto the vinyl groups on the surface of the MOF layer, thereby chemically bonding the phosphorus-containing organosilicon copolymer to the MOF layer surface, forming a stable and robust shell structure.

[0014] Through the above three-step reaction, the present invention successfully constructed a three-layer structure of "antimony trioxide core - MOF intermediate layer - phosphorus-containing organosilicon shell". The layers are tightly bonded, the interfacial bonding strength is high, and the structure is stable.

[0015] In a preferred embodiment of the present invention, the average particle size of antimony trioxide in step 1 is 1-5 μm. Selecting antimony trioxide within this particle size range ensures that the core has sufficient specific surface area to support the MOF interlayer, avoids agglomeration problems caused by excessively small particle size, and is also beneficial for subsequent coating and dispersion.

[0016] In a preferred embodiment of the present invention, the molar ratio of 2-methylimidazole to 2-vinylimidazole in step 2 is 1-3:1-3. By adjusting the ratio of the two imidazole ligands, the pore size, surface functional group density, and crystallinity of the MOF interlayer can be controlled. A higher proportion of 2-vinylimidazole results in more vinyl sites on the MOF layer surface that can participate in subsequent polymerization reactions, which is beneficial for forming a denser phosphorus-containing organosilicon shell; however, an excessively high proportion of 2-vinylimidazole may affect the regularity of the MOF crystal structure. Therefore, within this preferred range, a MOF interlayer with a regular structure and abundant surface active sites can be obtained.

[0017] In a preferred embodiment of the present invention, the stirring reaction temperature in step 2 is 50-70℃, and the time is 1-4 hours; the static crystallization time is 12-48 hours. The stirring reaction stage facilitates the rapid nucleation of MOFs on the nucleus surface, while the subsequent static crystallization stage is beneficial for the improvement and growth of the MOF crystal structure. By controlling the reaction time and temperature, the thickness and density of the MOF layer can be controlled.

[0018] In a preferred embodiment of the present invention, the mass ratio of vinyl DOPO to octavinyl-POSS is 1-9:1. By adjusting the ratio of the two monomers, the chemical composition and properties of the shell can be controlled. A higher content of octavinyl-POSS results in more pronounced organosilicon characteristics in the shell, and better material compatibility and thermal stability; a higher content of vinyl DOPO results in a higher phosphorus content in the shell, and more outstanding flame-retardant properties. Within this preferred range, both flame-retardant properties and compatibility can be simultaneously achieved.

[0019] In a preferred embodiment of the present invention, the vinyl DOPO is obtained by reacting DOPO with p-alkenylbenzaldehyde. This reaction involves an addition reaction between the PH bond in DOPO and the aldehyde group in p-alkenylbenzaldehyde to generate a vinyl-containing DOPO derivative. The reaction conditions are mild, the yield is high, and the resulting product has a well-defined structure and high purity.

[0020] In a preferred embodiment of the present invention, the p-alkenylbenzaldehyde is any one of p-vinylbenzaldehyde, p-propenylbenzaldehyde, p-butenylbenzaldehyde, p-pentenylbenzaldehyde, and p-hexenylbenzaldehyde. Alkenylbenzaldehydes with different carbon chain lengths can regulate the molecular structure and reactivity of vinyl DOPO, thereby affecting the crosslinking density and flexibility of the shell polymer.

[0021] In a preferred embodiment of the present invention, the initiator is azobisisobutyronitrile (AIBN), and its mass is 0.2%-0.5% of the total mass of vinyl DOPO and octavinyl-POSS. AIBN is a commonly used oil-soluble free radical initiator. Within this dosage range, it can effectively initiate polymerization reactions while avoiding side reactions or product color darkening caused by excessive initiator.

[0022] In a preferred embodiment of the present invention, the polymerization temperature in step 3 is 60-80°C. This temperature range is within the effective decomposition temperature range of the AIBN initiator, ensuring the smooth progress of the polymerization reaction while avoiding potential damage to the MOF structure or solvent evaporation caused by excessively high temperatures.

[0023] This invention provides a composite functional material based on antimony trioxide and its preparation method, which has the following beneficial effects: This invention is the first to propose and prepare a three-layer core-shell structure composite functional material consisting of an antimony trioxide core, a MOF intermediate layer, and a phosphorus-containing organosilicon shell. This multi-layer, multi-component structural design makes full use of the characteristics of each layer and achieves structural stability and functional synergy through interlayer chemical bonding.

[0024] This invention combines the gas-phase flame-retardant mechanism of antimony trioxide, the catalytic char formation mechanism of MOFs, and the condensed-phase flame-retardant mechanism of phosphorus-containing organosilicon, forming a multi-dimensional, multi-pathway synergistic flame-retardant system. During combustion, antimony trioxide captures free radicals in the gas phase, MOFs catalyze the formation of a dense char layer on the matrix material, and the phosphorus-containing organosilicon further enhances the heat insulation and oxygen barrier effects of the char layer. The synergistic effect of these three components allows the material to achieve excellent flame-retardant performance even with low addition levels, significantly improving the limiting oxygen index, achieving a UL-94 vertical burning rating of V-0, and significantly reducing key flame-retardant parameters such as heat release rate and total heat release.

[0025] The outermost layer of the material in this invention is a phosphorus-containing organosilicon shell. This shell possesses the characteristics of organosilicon, exhibiting low surface energy and good compatibility with various polymer matrices. Compared to traditional unmodified antimony trioxide, the composite functional material of this invention demonstrates significantly improved dispersibility in the matrix and a marked reduction in agglomeration. Therefore, while imparting excellent flame-retardant properties to the matrix material, it does not cause significant deterioration in the mechanical properties of the matrix material.

[0026] The preparation method offers high controllability: This invention employs a stepwise synthesis strategy. First, the core is surface-modified. Then, an intermediate MOF layer is grown in situ on the core surface through coordination. Finally, a phosphorus-containing organosilicon shell is grafted via free radical polymerization. Each step is performed under mild conditions, is simple to operate, and is independent of the others, facilitating precise control of the structure of each layer. Therefore, this method is suitable for industrial-scale production, ensuring stable and controllable product quality. Attached Figure Description

[0027] Figure 1 This is the synthetic route for the vinyl DOPO prepared in Example 1. Detailed Implementation

[0028] Unless otherwise specified in the examples, the conditions were performed under standard conditions or as recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products. Techniques not mentioned in this invention refer to existing technologies. Unless otherwise specified, the following examples and comparative examples are parallel experiments, using the same processing steps and parameters. Example 1:

[0029] A method for preparing a composite functional material based on antimony trioxide is as follows: Step 1: Weigh 10g of antimony trioxide (Dazheng Chemical, average particle size 2μm) and add it to 100mL of ethanol solution of mercaptoacetic acid (1mmol / L). Sonicate at room temperature for 24h, centrifuge to collect the precipitate, and wash it three times each with distilled water and anhydrous ethanol to obtain mercaptoacetic acid modified antimony trioxide, which can be stored for later use.

[0030] Step 2: Dissolve 0.08 mol 2-methylimidazole, 0.08 mol 2-vinylimidazole and 0.02 mol zinc nitrate hexahydrate in 800 mL methanol, then add the above-mentioned thioglycolic acid-modified antimony trioxide, stir and react in a water bath at 60 °C for 2 h, then stop stirring and let it stand to crystallize and grow for 12 h, cool to room temperature, centrifuge to collect the precipitate, wash it three times each with distilled water and anhydrous ethanol, and then disperse it in anhydrous toluene to obtain a dispersion.

[0031] Step 3: Weigh 0.1 mol of 4-(3-butenyl)benzaldehyde and 0.1 mol of DOPO. First, heat 500 mL of dichloroethane to 65 °C with stirring. Add DOPO and wait until it is completely dissolved in dichloroethane. Then, slowly add 4-(3-butenyl)benzaldehyde and 1 mL of triethylamine. After the addition is complete, reflux for 5 h. After the reaction is complete, concentrate under reduced pressure to obtain the crude product. Purify the crude product by column chromatography (petroleum ether: ethyl acetate = 5:1). Concentrate the collected eluent to obtain vinyl DOPO, with a yield of 69.2%. The synthetic route is shown below. Figure 1 HPLC purity 99.2%, ESI-MS (m / z) (M + Theoretical value: 376.39, measured value: 376.22. 1H NMR: δ2.19-2.31 (2H, 2.25 (q, J = 7.4 Hz), 2.25 (q, J = 7.4 Hz)), 2.74-2.86 (2H,2.80 (t, J = 7.4 Hz), 2.80 (t, J = 7.4 Hz)), 4.74-4.89 (2H, 4.81 (dd, J =17.0, 2.5 Hz), 4.81 (dd, J = 10.5, 2.5 Hz)), 5.63 (1H, ddt, J = 17.0, 10.5,7.4 Hz), 6.19 (1H, s), 7.00 (2H, ddd, J = 8.2, 1.3, 0.5 Hz), 7.27 (2H, ddd, J = 8.2, 1.1, 0.5 Hz), 7.36-7.78 (7H, 7.42 (ddd, J = 8.2, 1.3, 0.5 Hz), 7.44 (ddd, J = 7.7, 7.4, 1.3 Hz), 7.47 (ddd, J = 8.1, 7.4, 1.3 Hz), 7.53 (ddd, J =8.2, 7.4, 1.6 Hz), 7.66 (ddd, J = 8.1, 7.4, 1.5 Hz), 7.66 (ddd, J = 8.1, 1.6,0.5 Hz), 7.72 (ddd, J = 7.7, 1.5, 0.5 Hz)), 7.88 (1H, (ddd, J = 8.1, 1.3, 0.5Hz). Under nitrogen protection, 4g of the above vinyl DOPO and 1g of octavinyl-POSS were added to the dispersion, followed by 5mg of free radical initiator AIBN. The mixture was heated to 70℃ and stirred for 15h. After the reaction was completed, the mixture was brought back to room temperature, and the product was collected by centrifugation. The product was then vacuum dried at 60℃ for 12h to obtain the composite functional material. Example 2:

[0032] The procedure is basically the same as in Example 1, except that 0.04 mol of 2-methylimidazole and 0.12 mol of 2-vinylimidazole are added in step 2. Example 3:

[0033] The procedure is basically the same as in Example 1, except that 0.12 mol of 2-methylimidazole and 0.04 mol of 2-vinylimidazole are added in step 2. Example 4:

[0034] Similar to Example 1, except that 4-vinylbenzaldehyde was used instead of 4-(3-butenyl)benzaldehyde. Yield 70.1%, HPLC purity 99.4%, ESI-MS (m / z) (M + Theoretical value: 348.34, measured value: 348.50. Example 5:

[0035] The results were essentially the same as in Example 1, except that 4-allylbenzaldehyde was used instead of 4-(3-butenyl)benzaldehyde. Yield: 67.8%, HPLC purity: 99.1%, ESI-MS (m / z) (M + Theoretical value: 362.36, measured value: 362.18.

[0036] Comparative Example 1: It is basically the same as Example 1, except that antimony trioxide is not modified with mercaptoacetic acid.

[0037] Comparative Example 2: It is basically the same as Example 1, except that octavinyl-POSS is not added.

[0038] Comparative Example 3: The procedure is basically the same as in Example 1, except that 0.16 mol of 2-methylimidazole is added in step 2.

[0039] Comparative Example 4: It is basically the same as Example 1, except that it does not undergo a polymerization reaction.

[0040] A method for preparing a composite functional material based on antimony trioxide is as follows: Step 1: Weigh 10g of antimony trioxide (Dazheng Chemical, average particle size 2μm) and add it to 100mL of ethanol solution of mercaptoacetic acid (1mmol / L). Sonicate at room temperature for 24h, centrifuge to collect the precipitate, and wash it three times each with distilled water and anhydrous ethanol to obtain mercaptoacetic acid modified antimony trioxide, which can be stored for later use.

[0041] Step 2: Dissolve 0.08 mol 2-methylimidazole, 0.08 mol 2-vinylimidazole and 0.02 mol zinc nitrate hexahydrate in 800 mL methanol, then add the above-mentioned thioglycolic acid-modified antimony trioxide, stir and react in a 60 °C water bath for 2 h, then stop stirring and let it stand to crystallize and grow for 12 h, cool to room temperature, centrifuge to collect the precipitate, wash it three times each with distilled water and anhydrous ethanol, and vacuum dry it at 60 °C for 12 h.

[0042] Experimental groups 1-9: The composite functional materials, decabromodiphenyl ether, PTFE anti-dripping agent, and acrylonitrile-butadiene-styrene copolymer (ABS) prepared in Examples 1-5 and Comparative Examples 1-4 were mixed uniformly using a mixer at a mass ratio of 3:10:0.3:86.7. The mixture was granulated using a twin-screw extruder, and the granules were dried at 110°C. The granules were then injection molded into samples for experimental groups 1-9 using an injection molding machine. The operating parameters of the injection molding machine were as follows: the temperatures of zones 1, 2, 3, 4, and 5 were 170°C, 190°C, 230°C, 235°C, and 235°C, respectively.

[0043] Control group 1: Commercially available antimony trioxide (Dazheng Chemical, average particle size 2μm), decabromodiphenyl ether, PTFE anti-dripping agent, and acrylonitrile-butadiene-styrene copolymer (ABS) were mixed uniformly using a mixer at a mass ratio of 3:10:0.3:86.7. The mixture was granulated using a twin-screw extruder, and the granules were dried at 110℃. The granules were then injection molded into control group 1 sample using an injection molding machine. The operating parameters of the injection molding machine were as follows: the temperatures of zones 1, 2, 3, 4, and 5 were 170℃, 190℃, 230℃, 235℃, and 235℃, respectively.

[0044] Control group 2: Decabromodiphenyl ether, PTFE anti-dripping agent, and acrylonitrile-butadiene-styrene copolymer (ABS) were mixed uniformly using a mixer at a mass ratio of 10:0.3:86.7. The mixture was then granulated using a twin-screw extruder. After drying the granules at 110°C, they were injection molded into control group 2 samples using an injection molding machine. The operating parameters of the injection molding machine were as follows: the temperatures of zones 1, 2, 3, 4, and 5 were 170°C, 190°C, 230°C, 235°C, and 235°C, respectively.

[0045] Performance testing: Performance tests were conducted on the samples in experimental groups 1-9 and control groups 1-2.

[0046] ①Oxygen index data were collected using an oxygen index tester. The test standard was in accordance with GB / T 2406.2-2009 Oxygen Index Determination Method. The sample size was 100mm×6.5mm×3mm.

[0047] ② The flame retardant performance data were collected using a cone calorimeter, and the testing standard was in accordance with ISO 5660-1:2015. The sample size was 100mm×100mm×3mm, and the radiation intensity was selected as 35kW / m². 2 .

[0048] ③ Tensile properties: Tensile tests were conducted on the specimens using a multi-functional testing bench in accordance with GB / T 1040.1-2018. The average cross-sectional area of ​​the specimens was 37.24 mm². 2The tensile test rate was 10 mm / min, and the initial gauge length was 50 mm. At least 5 samples were tested, and the average value was taken.

[0049] ④ Cantilever beam notched impact strength: In accordance with GB / T 1843-2008, the cantilever beam impact testing machine was used to conduct notched impact tests on the specimens. The pendulum speed was set to 3.5 m / s, the pendulum energy was 5.5 J, and the radius of the notch bottom was (1.00±0.05) mm. At least 5 samples were tested, and the average value of the results was taken.

[0050] The test results are shown in Table 1: Table 1: The above comparisons fully demonstrate the effectiveness and superiority of the technical solution of this invention. By constructing a three-layer core-shell structure of "antimony trioxide core - MOF intermediate layer - phosphorus-containing organosilicon shell layer" and adopting a stepwise preparation strategy of "thioglycolic acid surface modification - in-situ growth of MOFs - free radical polymerization grafting", this invention successfully prepared a novel composite functional material with stable structure and excellent performance. This material exhibits excellent technical effects in terms of flame retardancy, compatibility, and mechanical property retention, providing a new approach and technical method for the development of high-performance flame-retardant functional materials.

[0051] Analysis of experimental groups 1-3 (Examples 1-3) showed that an equimolar ratio likely resulted in the densest ZIF-8 shell with the most uniform distribution of functional groups. This ensured good interfacial compatibility, provided sufficient active sites for subsequent grafting, and did not excessively compromise the rigidity of the ZIF-8 framework. Excessive 2-vinylimidazole may have disrupted the regular crystal structure of ZIF-8, leading to a decrease in shell coating density or uneven distribution of grafts. Conversely, insufficient vinyl content resulted in a reduction in the amount of DOPO and POSS grafted later, thus lowering the flame retardant efficiency.

[0052] Analysis of experimental groups 4-5 (Examples 4-5) revealed that differences in molecular chain segment length and reactivity resulted in a less effective "bridging" effect after grafting compared to 4-(3-butenyl)benzaldehyde. This may affect stress transfer and crosslinking density between the polymer network and inorganic particles.

[0053] Analysis of Experimental Group 6 (Comparative Example 1) showed that modification with mercaptoacetic acid was crucial. Without modification, antimony trioxide had weak bonding with the ZIF-8 shell, making it prone to aggregation or peeling, resulting in the failure of both flame retardant and toughening effects.

[0054] Analysis of Experimental Group 7 (Comparative Example 2) showed that POSS, as a nano-reinforcing agent and char-forming promoter, worked synergistically with DOPO to improve flame retardant efficiency and material rigidity.

[0055] Analysis of experimental group 8 (comparative example 3) showed that without the introduction of 2-vinylimidazole to the active site, the DOPO / POSS network could not be grafted subsequently, the chemical bond between the flame retardant and the matrix disappeared, resulting in a significant degradation in performance.

[0056] Analysis of experimental group 9 (comparative example 4) showed that the organic-inorganic hybrid network formed by the surface polymerization reaction is a key step in improving flame retardant efficiency. Although the simple ZIF-8 shell has a certain barrier effect, it lacks the synergistic effect of flame retardant elements (phosphorus, silicon).

[0057] Analysis of control groups 1-2 showed that the addition of traditional antimony trioxide severely degraded the mechanical properties of the polymer matrix. However, after modification, the material not only had its flame retardancy greatly improved, but its mechanical properties were even slightly improved, achieving a balance between reinforcement and flame retardancy.

[0058] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite functional material based on antimony trioxide, characterized in that, include: Antimony trioxide nuclei; MOF intermediate layer; Phosphorus-containing organosilicon shell.

2. A method for preparing the composite functional material as described in claim 1, characterized in that, include: Step 1: Modify antimony trioxide with mercaptoacetic acid; Step 2: Dissolve 2-methylimidazole, 2-vinylimidazole and zinc salt in methanol, add antimony trioxide modified with thioglycolic acid obtained in Step 1, and prepare a dispersion after stirring, reaction and static crystallization. Step 3: Under nitrogen protection, vinyl DOPO and octavinyl-POSS are added to the dispersion obtained in step 2, and the polymerization reaction is carried out in the presence of a free radical initiator.

3. The method for preparing the composite functional material as described in claim 2, characterized in that, In step 1, the average particle size of antimony trioxide is 1-5 μm.

4. The method for preparing the composite functional material as described in claim 2, characterized in that, In step 2, the molar ratio of 2-methylimidazole to 2-vinylimidazole is 1-3:1-3.

5. The method for preparing the composite functional material as described in claim 2, characterized in that, In step 2, the stirring reaction temperature is 50-70℃ and the time is 1-4h; the standing crystallization time is 12-48h.

6. The method for preparing the composite functional material as described in claim 2, characterized in that, The mass ratio of vinyl DOPO to octavinyl-POSS is 1-9:

1.

7. The method for preparing the composite functional material as described in claim 2, characterized in that, The vinyl DOPO is obtained by reacting DOPO with p-alkenylbenzaldehyde.

8. The method for preparing the composite functional material as described in claim 7, characterized in that, The p-alkenylbenzaldehyde is any one of p-vinylbenzaldehyde, p-propenylbenzaldehyde, p-butenylbenzaldehyde, p-pentenylbenzaldehyde, and p-hexenylbenzaldehyde.

9. The method for preparing the composite functional material as described in claim 2, characterized in that, The initiator is azobisisobutyronitrile, and its mass is 0.2%-0.5% of the total mass of vinyl DOPO and octavinyl-POSS.

10. The method for preparing the composite functional material as described in claim 2, characterized in that, The polymerization reaction in step 3 is carried out at a temperature of 60-80℃.

Images