Boron-loaded hollow zirconium-based organic octahedral material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of flame-retardant fireproof materials, in particular to a boron-loaded hollow zirconium-based organic octahedral material and a preparation method and application thereof.The preparation method comprises the steps that an adjustable zirconium-based metal organic octahedral material serves as a matrix, the matrix is evenly dispersed in a phenolic acid solution, an etching reaction is conducted at the room temperature, and hollow H-UiO66 is obtained; the preparation method comprises the following steps: dispersing hollow H-UiO66 in boric acid, and carrying out ultrasonic stirring treatment at room temperature to obtain the boron-loaded hollow zirconium-based metal organic octahedral material B-H-UiO66. The boron-loaded organic octahedral material with a hollow structure is obtained by utilizing simple acid etching and physical loading methods, and the flame-retardant epoxy resin composite material prepared from the boron-loaded organic octahedral material as a flame retardant and epoxy resin has good flame retardance and smoke suppression performance.

Description

Technical Field

[0001] The present invention relates to the technical field of flame-retardant and fire-proof materials, and particularly relates to a boron-loaded hollow zirconium-based organic octahedron material, a preparation method thereof, and an application thereof. Background Art

[0002] Polymer materials have attracted extensive attention due to their excellent properties and mild synthesis processes. However, the inherent flammability of polymers hinders their practical applications in many fields, and the large amount of heat and toxic smoke released during the combustion of polymers are the main causes of death for humans and animals. Therefore, the design of new polymer composites with good flame retardancy, thermal stability, and smoke suppression has become the focus of attention.

[0003] Due to the high porosity and specific surface area of crystalline porous materials with a periodic network structure, metal-organic framework materials (MOFs) have been widely used in the fields of catalysis, energy, optoelectronics, etc. MOFs have excellent thermal stability and catalytic properties and can be used to construct excellent polymer composites, which theoretically can improve the safety performance of polymers. In addition, MOFs are self-assembled by metal-containing units and organic linkers through coordination bonds. Compared with inorganic flame retardants, the organic ligands of MOFs not only enhance the compatibility with polymers but also provide flame retardant groups and elements. Compared with organic flame retardants, the internal pores and metals of MOFs effectively promote the adsorption and catalytic carbonization of pyrolysis volatiles, thereby inhibiting the release of toxic smoke.

[0004] Considering that the smoke generated during the combustion of polymers is generally incompletely combusted volatiles with too large particle sizes to be captured by the micropores of MOFs. Currently, synthesizing hollow MOFs with complex open nanostructures is a promising method to solve this problem, which improves the capture ability of MOFs materials for pyrolysis volatiles. The open nanostructure of hollow MOFs can easily encapsulate objects in its slender cavities or channels. Due to the excellent properties of hollow MOFs, a large number of experiments have been carried out on the rational synthesis of hollow MOFs materials. However, the existing synthesis methods of hollow MOFs materials cannot effectively control the size and shape of the hollow structure. Summary of the Invention

[0005] Aiming at the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide a boron-loaded hollow zirconium-based organic octahedron material, a preparation method thereof, and an application thereof. The present invention obtains a zirconium-based metal-organic octahedron material with adjustable hollow structure by using a simple acid etching method, and then loads the flame retardant element boron on the hollow zirconium-based metal-organic octahedron material with a large specific surface area through a simple physical adsorption method, thereby preparing a boron-loaded hollow zirconium-based organic octahedron material.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions: A preparation method of a boron-loaded hollow zirconium-based metal-organic octahedron material, comprising the following steps: In a reaction solvent, using a zirconium source as a raw material and terephthalic acid as a ligand to obtain a mixed solution, adding acetic acid to the mixed solution, and carrying out a hydrothermal reaction at a temperature of 100 °C to 130 °C for 20 h to 24 h to obtain a zirconium-based metal-organic octahedron material.

[0007] Using the zirconium-based metal-organic octahedron material as a matrix, uniformly dispersing it in a phenolic acid solution, and carrying out an etching reaction at room temperature to obtain a hollow zirconium-based metal-organic octahedron material, abbreviated as H-UiO66.

[0008] Uniformly dispersing the H-UiO66 in boric acid and carrying out ultrasonic stirring treatment at room temperature to obtain a boron-loaded hollow zirconium-based metal-organic octahedron material.

[0009] The present invention prepares a zirconium-based metal-organic octahedron material with adjustable size. Using the zirconium-based metal-organic octahedron material with adjustable size as a matrix, uniformly dispersing it in a phenolic acid solution, and carrying out an etching reaction at room temperature to obtain H-UiO66 with an adjustable hollow structure. Phenolic acids can release free protons, which can be used to destroy the framework of MOFs, and their relatively large molecular size allows them to block the pores of MOFs, thereby protecting the MOFs from complete collapse, and finally endowing the MOFs with a hollow structure. During the preparation of MOFs, by controlling the addition amount of phenolic acids, the size of MOFs can be adjusted. Finally, dispersing the H-UiO66 with an adjustable hollow structure in boric acid and carrying out ultrasonic stirring treatment at room temperature, the present invention obtains a boron-loaded metal-organic octahedron material with a hollow structure by using a simple acid etching and physical loading method.

[0010] In a preferred embodiment of the present invention, the mass ratio of the zirconium source to terephthalic acid is 1:0.8.

[0011] In a preferred embodiment of the present invention, the mass ratio of acetic acid, terephthalic acid and the reaction solvent is 1 to 12:0.8:180 to 220.

[0012] In a preferred embodiment of the present invention, the dosage ratio of the zirconium-based metal-organic octahedron material to the phenolic acid solution is 0.2 g:200 mL to 250 mL, and the concentration of the phenolic acid solution is 3 g to 10 g:1000 mL.

[0013] In a preferred embodiment of the present invention, the phenolic acid solution is tannic acid or gallic acid.

[0014] In a preferred embodiment of the present invention, the etching reaction time is 10 min to 20 min.

[0015] In a preferred embodiment of the present invention, the mass ratio of the hollow H-UiO66 to boric acid is 1:2 to 4.

[0016] In a preferred embodiment of the present invention, the phenolic acid solution is obtained by the following method: The phenolic acid is uniformly dispersed in water to obtain an acid solution, where the dosage ratio of the phenolic acid to water is 3 g to 10 g:1000 mL.

[0017] In a preferred embodiment of the present invention, the ultrasonic stirring treatment time is 0.5 h to 1 h.

[0018] In a preferred embodiment of the present invention, the preparation steps of the adjustable zirconium-based metal-organic octahedron material are as follows: The zirconium source and terephthalic acid are placed in a reaction solvent and subjected to stirring treatment to obtain a mixed solution; after adding different amounts of acetic acid to the mixed solution, hydrothermal reaction is carried out at a temperature of 100 °C to 130 °C for 20 h to 24 h, followed by centrifugation, washing, and drying to obtain the adjustable zirconium-based metal-organic octahedron material UiO66.

[0019] Among them, the zirconium source is zirconium tetrachloride; the reaction solvent is DMF; and the mass ratio of the zirconium source, terephthalic acid, reaction solvent, and acetic acid is 1:0.8:180 to 220:1 to 12.

[0020] The stirring rate of the stirring treatment is 80 r / min to 120 r / min, and the stirring time is 10 min to 30 min.

[0021] Another object of the present invention is to provide a boron-loaded hollow zirconium-based organic octahedron material prepared by the preparation method described in any one of the above.

[0022] The third object of the present invention is to provide an application of the boron-loaded hollow zirconium-based organic octahedron material described above in a flame-retardant epoxy resin composite material. The application method is as follows: The thermosetting E51 bisphenol A epoxy resin is heated and stirred evenly, and then, with the boron-loaded hollow zirconium-based organic octahedron material as the supporting matrix, it is placed in an organic solvent together with the heated thermosetting E51 bisphenol A epoxy resin, and after stirring treatment until the system becomes transparent, air is then evacuated until no bubbles are generated to obtain a mixture.

[0023] A curing agent is added to the mixture. After the curing agent is completely dissolved, it is cured at 80 °C to 100 °C for 2 h to 3 h, 120 °C to 140 °C for 1 h to 2 h, and 160 °C to 180 °C for 1 h to 2 h in sequence to obtain the flame-retardant epoxy resin composite material.

[0024] In a preferred embodiment of the present invention, the organic solvent is any one of dichloromethane, chloroform and acetone; in the mixture, the addition amount of the boron-loaded hollow zirconium-based metal-organic octahedron material is 1 wt% - 7 wt% of the mass of the thermosetting E51 bisphenol A epoxy resin after heating; the curing agent is 4,4-diaminodiphenylmethane, and the mass ratio of the curing agent to the mixture is 1:4 - 5.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In the present invention, zirconium-based organic octahedron materials with adjustable sizes are prepared. Using the zirconium-based metal-organic octahedron materials with adjustable sizes as the matrix, they are uniformly dispersed in the phenolic acid solution, and an etching reaction is carried out at room temperature to obtain H-UiO66 with an adjustable hollow structure. The phenolic acid will release free protons, which can be used to destroy the framework of MOFs. Moreover, the relatively large molecular size of the phenolic acid can block the pores of MOFs, thereby protecting the MOFs from complete collapse, and finally endowing the MOFs with a hollow structure. During the preparation of MOFs, the size of the MOFs can be adjusted by controlling the addition amount of acetic acid. Finally, the H-UiO66 with an adjustable hollow structure is dispersed in boric acid, and ultrasonic stirring treatment is carried out at room temperature. The present invention obtains a boron-loaded metal-organic octahedron material with a hollow structure by using a simple acid etching and physical loading method.

[0026] 2. The novel boron-loaded hollow zirconium-based metal-organic octahedron material prepared in the present invention contains boron, a hollow structure and metal at the same time. The boron element forms a glassy coating covering the epoxy resin during combustion, playing an insulating role. In addition, bound water is released at the combustion temperature, playing a cooling and endothermic role and changing the thermal decomposition pathway of the combustible, inhibiting the generation of combustible gases; the hollow structure can adsorb and collect the combustible gases generated by combustion, thereby inhibiting combustion; the metal element promotes catalytic carbonization, and the formed dense carbon layer can prevent the heat and gas exchange between the condensed phase and the gas phase. The synergistic effect among the three improves the flame retardancy and smoke suppression performance of the epoxy resin composite material, which has certain guiding significance for improving the flame retardancy performance of the epoxy resin.

[0027] 3. Using the prepared B-H-UiO66 and epoxy resin as the flame retardant and matrix material respectively, a novel flame retardant epoxy resin composite material is developed. The results show that the flame retardant epoxy resin composite material prepared in the present invention has good flame retardancy and smoke suppression performance. Description of the Drawings

[0028] Figure 1SEM and TEM images of the boron-loaded hollow zirconium-based metal-organic octahedron material prepared in Example 1 of the present invention. Among them, (A) is the SEM image of B-H-UiO66, and (B) is the TEM image of B-H-UiO66.

[0029] Figure 2 SEM and TEM images of the boron-loaded hollow zirconium-based metal-organic octahedron material prepared in Example 2 of the present invention. Among them, (A) is the SEM image of B-H-UiO66, and (B) is the TEM image of B-H-UiO66.

[0030] Figure 3 SEM and TEM images of the boron-loaded hollow zirconium-based metal-organic octahedron material prepared in Example 3 of the present invention. Among them, (A) is the SEM image of B-H-UiO66, and (B) is the TEM image of B-H-UiO66.

[0031] Figure 4 SEM and TEM images of the boron-loaded hollow zirconium-based metal-organic octahedron material prepared in Example 4 of the present invention. Among them, (A) is the SEM image of B-H-UiO66, and (B) is the TEM image of B-H-UiO66.

[0032] Figure 5 FTIR spectra of UiO66, H-UiO66, and B-H-UiO66 prepared in Example 1 of the present invention.

[0033] Figure 6 Heat release rate curves of the flame-retardant epoxy resin composites prepared in Application Example 1 of the present invention and Comparative Examples 1-3.

[0034] Figure 7 Total heat release curves of the flame-retardant epoxy resin composites prepared in Application Example 1 of the present invention and Comparative Examples 1-3.

[0035] Figure 8 Smoke release curves of the flame-retardant epoxy resin composites prepared in Application Example 1 of the present invention and Comparative Examples 1-3.

[0036] Figure 9 Total smoke release curves of the flame-retardant epoxy resin composites prepared in Application Example 1 of the present invention and Comparative Examples 1-3. Detailed implementation manners

[0037] Combined with the embodiments of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described with the preferred embodiments and the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0038] It should be noted that all the professional terms used in the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the protection scope of the present invention. Unless otherwise specifically stated, various raw materials, reagents, instruments and equipment used in the following embodiments of the present invention can be obtained through market purchase or prepared by existing methods.

[0039] The epoxy resin used in each of the following embodiments of the present invention is a thermosetting E51 bisphenol A epoxy resin.

[0040] Example 1 A preparation method of boron-loaded hollow zirconium-based metal-organic octahedron materials, comprising the following steps: (1) Mix 2.33 g of zirconium tetrachloride, 1.66 g of terephthalic acid and 240 mL of DMF in a single-necked flask and stir for 30 min. Then, drop 5 mL of acetic acid into the stirred solution, pour it into a reaction kettle, and carry out hydrothermal reaction at 120 °C for 24 h. Finally, centrifuge, wash and dry to obtain zirconium-based metal-organic octahedron material UiO66.

[0041] (2) Mix 5 g of tannic acid TA and 1000 mL of distilled water in a beaker and stir for 5 min to obtain a weak acid solution. Take 1 g of UiO66 prepared in step (1), disperse it evenly in the weak acid solution, react at room temperature for 10 min, and finally centrifuge and dry to obtain hollow metal-organic framework material H-UiO66.

[0042] (3) Disperse 1 g of H-UiO66 and 2 g of boric acid in 100 mL and 50 mL of distilled water respectively. Then, pour the above two solutions into a beaker, carry out ultrasonic stirring treatment at room temperature for 1 h, and finally wash and dry to obtain boron-loaded hollow zirconium-based metal-organic octahedron material B-H-UiO66.

[0043] Example 2 A preparation method of boron-loaded hollow zirconium-based metal-organic octahedron materials, comprising the following steps: (1) Mix 2.33 g of zirconium tetrachloride, 1.66 g of terephthalic acid, and 240 mL of DMF in a single-necked flask and stir for 30 min. Then, add 10 mL of acetic acid dropwise to the stirred solution, pour it into a reaction kettle, and carry out a hydrothermal reaction at 120 °C for 24 h. Finally, centrifuge, wash, and dry to obtain the zirconium-based metal-organic octahedral material UiO66.

[0044] (2) Mix 5 g of tannic acid TA and 1000 mL of distilled water in a beaker and stir for 5 min to obtain a weak acid solution. Take 1 g of the UiO66 prepared in step (1), disperse it evenly in the weak acid solution, react at room temperature for 10 min, and finally centrifuge and dry to obtain the hollow metal-organic framework material H-UiO66.

[0045] (3) Disperse 1 g of H-UiO66 and 2 g of boric acid in 100 mL and 50 mL of distilled water respectively. Then, pour the above two solutions into a beaker and carry out ultrasonic stirring treatment at room temperature for 1 h. Finally, wash and dry to obtain the boron-loaded hollow zirconium-based metal-organic octahedral material B-H-UiO66.

[0046] Example 3 A preparation method of a boron-loaded hollow zirconium-based metal-organic octahedral material, comprising the following steps: (1) Mix 2.33 g of zirconium tetrachloride, 1.66 g of terephthalic acid, and 240 mL of DMF in a single-necked flask and stir for 30 min. Then, add 15 mL of acetic acid dropwise to the stirred solution, pour it into a reaction kettle, and carry out a hydrothermal reaction at 120 °C for 24 h. Finally, centrifuge, wash, and dry to obtain the zirconium-based metal-organic octahedral material UiO66.

[0047] (2) Mix 5 g of tannic acid TA and 1000 mL of distilled water in a beaker and stir for 5 min to obtain a weak acid solution. Take 1 g of the UiO66 prepared in step (1), disperse it evenly in the weak acid solution, react at room temperature for 10 min, and finally centrifuge and dry to obtain the hollow metal-organic framework material H-UiO66.

[0048] (3) Disperse 1 g of H-UiO66 and 2 g of boric acid in 100 mL and 50 mL of distilled water respectively. Then, pour the above two solutions into a beaker and carry out ultrasonic stirring treatment at room temperature for 1 h. Finally, wash and dry to obtain the boron-loaded hollow zirconium-based metal-organic octahedral material B-H-UiO66.

[0049] Example 4 A preparation method of a boron-loaded hollow zirconium-based metal-organic octahedral material, comprising the following steps: (1) Mix 2.33 g of zirconium tetrachloride, 1.66 g of terephthalic acid and 240 mL of DMF in a single-necked flask and stir for 30 min. Then, drop 20 mL of acetic acid into the stirred solution, pour it into a reaction kettle, carry out hydrothermal reaction at 120 °C for 24 h, and finally centrifuge, wash and dry to obtain the zirconium-based metal-organic octahedral material UiO66.

[0050] (2) Mix 5 g of tannic acid TA and 1000 mL of distilled water in a beaker and stir for 5 min to obtain a weak acid solution. Take 1 g of the UiO66 prepared in step (1), disperse it evenly in the weak acid solution, react at room temperature for 10 min, and finally centrifuge and dry to obtain the hollow metal-organic framework material H-UiO66.

[0051] (3) Disperse 1 g of H-UiO66 and 2 g of boric acid in 100 mL and 50 mL of distilled water respectively. Then, pour the above two solutions into a beaker, carry out ultrasonic stirring treatment at room temperature for 1 h, and finally wash and dry to obtain the boron-loaded hollow zirconium-based metal-organic octahedral material B-H-UiO66.

[0052] Application Example 1 Take 2 g of the boron-loaded hollow zirconium-based metal-organic octahedral material B-H-UiO66 prepared in Example 1, 40 g of thermosetting E51 bisphenol A epoxy resin and 30 mL of dichloromethane, stir at 80 °C until transparent, evacuate until no bubbles are generated, then add 10 g of 4,4-diaminodiphenylmethane. After complete dissolution, pour it into a preheated mold and cure at 100 °C for 3 h, 120 °C for 2 h, and 160 °C for 1 h to obtain the flame-retardant epoxy resin composite B-H-UiO66 / EP.

[0053] Application Example 2 Take 1 g of the boron-loaded hollow zirconium-based metal-organic octahedral material B-H-UiO66 prepared in Example 1, 40 g of thermosetting E51 bisphenol A epoxy resin and 30 mL of dichloromethane, stir at 80 °C until transparent, evacuate until no bubbles are generated, then add 10 g of 4,4-diaminodiphenylmethane. After complete dissolution, pour it into a preheated mold and cure at 100 °C for 3 h, 120 °C for 2 h, and 160 °C for 1 h to obtain the flame-retardant epoxy resin composite B-H-UiO66 / EP.

[0054] Application Example 3 Take 3 g of the boron-loaded hollow zirconium-based metal-organic octahedron material B-H-UiO66 prepared in Example 1, 40 g of thermosetting E51 bisphenol A epoxy resin, and 30 mL of dichloromethane, stir at 80 °C until transparent, evacuate until no bubbles are generated, then add 10 g of 4,4-diaminodiphenylmethane. After complete dissolution, pour it into a preheated mold and cure at 100 °C for 3 h, 120 °C for 2 h, and 160 °C for 1 h to obtain the flame-retardant epoxy resin composite B-H-UiO66 / EP.

[0055] Application Example 4 Take 4 g of the boron-loaded hollow zirconium-based metal-organic octahedron material B-H-UiO66 prepared in Example 1, 40 g of thermosetting E51 bisphenol A epoxy resin, and 30 mL of dichloromethane, stir at 80 °C until transparent, evacuate until no bubbles are generated, then add 10 g of 4,4-diaminodiphenylmethane. After complete dissolution, pour it into a preheated mold and cure at 100 °C for 3 h, 120 °C for 2 h, and 160 °C for 1 h to obtain the flame-retardant epoxy resin composite B-H-UiO66 / EP.

[0056] Comparative Example 1 Stir 40 g of thermosetting E51 bisphenol A epoxy resin and 30 mL of dichloromethane at 80 °C until transparent, evacuate until no bubbles are generated, then add 10 g of 4,4-diaminodiphenylmethane. After complete dissolution, pour it into a preheated mold and cure at 100 °C for 3 h, 120 °C for 2 h, and 160 °C for 1 h to obtain a pure epoxy resin material, denoted as EP.

[0057] Comparative Example 2 Take 2 g of UiO66 prepared in Example 1, 40 g of thermosetting E51 bisphenol A epoxy resin, and 30 mL of dichloromethane, stir at 80 °C until transparent, evacuate until no bubbles are generated, then add 10 g of 4,4-diaminodiphenylmethane. After complete dissolution, pour it into a preheated mold and cure at 100 °C for 3 h, 120 °C for 2 h, and 160 °C for 1 h to obtain the flame-retardant epoxy resin composite UiO66 / EP.

[0058] Comparative Example 3 Take 2 g of the boron-free hollow zirconium-based metal-organic octahedron material H-UiO66 prepared in Example 1, 40 g of thermosetting E51 bisphenol A epoxy resin, and 30 mL of dichloromethane, stir at 80 °C until transparent, evacuate until no bubbles are generated, then add 10 g of 4,4-diaminodiphenylmethane. After complete dissolution, pour it into a preheated mold and cure at 100 °C for 3 h, 120 °C for 2 h, and 160 °C for 1 h to obtain the flame-retardant epoxy resin composite H-UiO66 / EP.

[0059] Result analysis 1. Morphology analysis Taking the boron-loaded hollow zirconium-based metal-organic octahedron material B-H-UiO66 prepared in Examples 1 to 4 of the present invention as an example, the morphology of the above boron-loaded hollow zirconium-based metal-organic octahedron material was observed using a thermal field emission scanning electron microscope and a transmission electron microscope, and the measured results are as follows Figures 1-4 shown, where Figure 1 (A) in is the SEM of B-H-UiO66 prepared in Example 1, Figure 1 (B) in is the TEM image of B-H-UiO66 prepared in Example 1, Figure 2 (A) in is the SEM of B-H-UiO66 prepared in Example 2, Figure 2 (B) in is the TEM image of B-H-UiO66 prepared in Example 2, Figure 3 (A) in is the SEM of B-H-UiO66 prepared in Example 3, Figure 3 (B) in is the TEM image of B-H-UiO66 prepared in Example 3, Figure 4 (A) in is the SEM of B-H-UiO66 prepared in Example 4, Figure 4 (B) in is the TEM image of B-H-UiO66 prepared in Example 4.

[0060] And it can be seen from Figures 1 to 4 that the boron-loaded hollow zirconium-based metal-organic octahedron material prepared in the present invention has uniform size and regular crystal form, and it can be clearly seen that the obtained metal-organic framework material has a hollow structure. In addition, the size of the obtained material can be effectively regulated by acetic acid.

[0061] 2. Infrared test Taking UiO66 obtained in step (1) of Example 1, H-UiO66 obtained in step (2) of Example 1, and B-H-UiO66 obtained in step (3) of Example 1 of the present invention as examples, they were respectively tested using an infrared spectrometer, and the test results are as follows Figure 5 shown.

[0062] And it can be seen from Figure 5 the structure of the molecule and the chemical bond combination in that a new peak appears at 1182 cm -1 in the infrared spectrum of B-H-UiO66, which belongs to the B-O vibration peak, indicating that the boron-loaded hollow zirconium-based metal-organic octahedron material of the present invention was successfully prepared.

[0063] 3. Flame retardancy test Taking the materials of Application Example 1 and Comparative Examples 1 to 3 of the present invention as examples, flame retardancy tests were respectively carried out on them, and the test results are as followsFigures 6-9 as shown

[0064] Figure 6 are the heat release curves of the materials of Application Example 1 and Comparative Examples 1 to 3, Figure 7 are the total heat release curves of the materials of Application Example 1 and Comparative Examples 1 to 3. It can be seen from Figure 6 and Figure 7 that compared with pure epoxy resin, the peak heat release of the flame-retardant epoxy resin composite material in this example is reduced by 55%, and the total heat release value is reduced by 38%, indicating that the flame retardancy is greatly improved.

[0065] Figure 8 are the smoke release curves of the materials of Application Example 1 and Comparative Examples 1 to 3, Figure 9 are the total smoke release curves of the materials of Application Example 1 and Comparative Examples 1 to 3. It can be seen from Figure 8 and Figure 9 that compared with pure epoxy resin, the peak smoke release of the flame-retardant epoxy resin composite material in this example is reduced by 65%, and the total smoke release value is reduced by 44%, indicating that the smoke suppression property is greatly improved.

[0066] Moreover, according to the international standard ASTM-D 2863, the oxygen index meter was used to test the oxygen index of the flame-retardant epoxy resin composite materials of Application Examples 1 to 4 respectively, and the test results are shown in Table 1.

[0067] Table 1 Test results of oxygen index and vertical burning grade The present invention also uses a vertical burning tester to test the vertical burning grade of the flame-retardant epoxy resin composite materials of Application Examples 1 to 4 respectively according to the international standard ASTM-D 3801, and the test results are shown in Table 1.

[0068] As can be seen from Table 1, the oxygen index of the flame-retardant epoxy resin composite material prepared by the present invention is 30.2% - 32.3%. According to the international standard ASTM-D 2863, the flame-retardant epoxy resin composite material prepared by the present invention belongs to a flame-retardant material.

[0069] In summary, the novel boron-loaded hollow zirconium-based metal-organic octahedron material prepared by the present invention contains boron, a hollow structure, and a metal at the same time. The boron element forms a glassy coating covering the epoxy resin during combustion, playing an insulating role. In addition, bound water is released at the combustion temperature, playing a cooling and endothermic role and changing the thermal decomposition pathway of some combustibles, inhibiting the generation of flammable gases. The hollow structure can adsorb and collect the combustible gases generated by combustion, thus inhibiting combustion. The metal element promotes catalytic carbonization, and the formed dense carbon layer can prevent the heat and gas exchange between the condensed phase and the gas phase. The synergistic effect among these three improves the flame retardancy and smoke suppression performance of the epoxy resin composite material, which has certain guiding significance for improving the flame retardancy of the epoxy resin.

[0070] It should be noted that when the present invention involves a numerical range, it should be understood that any value between the two endpoints of each numerical range and the two endpoints can be selected. Since the adopted step method is the same as that of the embodiment, in order to prevent repetition, the present invention describes the preferred embodiments. Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended protection scope is intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0071] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the present invention and its equivalent technologies, the present invention also intends to include these modifications and variations.

Claims

1. A preparation method of a boron-loaded hollow zirconium-based organic octahedron material, characterized in that, It includes the following steps: In a reaction solvent, using a zirconium source as a raw material and terephthalic acid as a ligand, a mixed solution is obtained. Acetic acid is added to the mixed solution, and a hydrothermal reaction occurs at a temperature of 100 °C to 130 °C for 20 h to 24 h to obtain a zirconium-based metal-organic octahedral material; Using the zirconium-based metal-organic octahedral material as a matrix, it is uniformly dispersed in a phenolic acid solution, and an acid etching reaction is carried out at room temperature to obtain a hollow zirconium-based metal-organic octahedral material; The hollow zirconium-based metal-organic octahedral material is uniformly dispersed in boric acid, and ultrasonic stirring treatment is carried out at room temperature to obtain a boron-loaded hollow zirconium-based organic octahedral material.

2. The preparation method of the boron-loaded hollow zirconium-based organic octahedron material according to claim 1, characterized in that The mass ratio of the zirconium source to terephthalic acid is 1:0.

8.

3. The preparation method of the boron-loaded hollow zirconium-based organic octahedron material according to claim 1, characterized in that, The mass ratio of acetic acid, terephthalic acid, and the reaction solvent is 1 to 12:0.8:180 to 220.

4. The preparation method of the boron-loaded hollow zirconium-based organic octahedron material according to claim 1, characterized in that, The dosage ratio of the zirconium-based metal-organic octahedral material to the phenolic acid solution is 0.2 g:200 mL to 250 mL. The phenolic acid solution is tannic acid or gallic acid, and the concentration of the phenolic acid solution is 3 g to 10 g:1000 mL.

5. The preparation method of the boron-loaded hollow zirconium-based organic octahedron material according to claim 1, wherein The mass ratio of the hollow H-UiO66 to boric acid is 1:2 to 4.

6. The preparation method of the boron-loaded hollow zirconium-based organic octahedron material according to claim 1, wherein, The phenolic acid solution is obtained by the following method: Phenolic acid is uniformly dispersed in water to obtain a phenolic acid solution, wherein the dosage ratio of phenolic acid to water is 3 g to 10 g:1000 mL.

7. The preparation method of the boron-loaded hollow zirconium-based organic octahedron material according to claim 1, characterized in that, The etching reaction time is 10 min to 20 min, and the ultrasonic stirring treatment time is 0.5 h to 1 h.

8. A boron-loaded hollow zirconium-based metal-organic octahedral material prepared by the preparation method according to any one of claims 1-7.

9. Use of the boron-loaded hollow zirconium-based organic octahedron material according to claim 8 in a flame-retardant epoxy resin composite material, characterized in that, The thermosetting E51 bisphenol A epoxy resin is heated and stirred evenly. Then, using the boron-loaded hollow zirconium-based metal-organic octahedral material as a support matrix, it is placed in an organic solvent with the heated thermosetting E51 bisphenol A epoxy resin. After stirring treatment until the system becomes transparent, then evacuated until no bubbles are generated to obtain a mixture; A curing agent is added to the mixture. After the curing agent is completely dissolved, it is cured at 80 °C to 100 °C for 2 h to 3 h, 120 °C to 140 °C for 1 h to 2 h, and 160 °C to 180 °C for 1 h to 2 h to obtain the flame-retardant epoxy resin composite material.

10. The application according to claim 9, wherein The organic solvent is any one of dichloromethane, chloroform, and acetone; in the mixture, the addition amount of the boron-loaded hollow zirconium-based metal-organic octahedral material is 1 wt% to 7 wt% of the mass of the heated thermosetting E51 bisphenol A epoxy resin; the curing agent is 4,4-diaminodiphenylmethane, and the mass ratio of the curing agent to the mixture is 1:4 to 5.

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