阅读说明：本技术 一种阻燃剂、阻燃环氧树脂及二者的制备方法 (Flame retardant, flame-retardant epoxy resin and preparation methods of flame retardant and flame-retardant epoxy resin ) 是由 屈红强 李佳贺 孟伟华 毕雪 彭珊 徐建中 于 2020-12-31 设计创作，主要内容包括：本发明涉及一种球磨石墨纳米片负载UiO-66-NH-2接枝HCCP阻燃剂、阻燃环氧树脂及二者的制备方法。球磨石墨纳米片负载UiO-66-NH-2接枝HCCP阻燃剂是通过下述方法制得：先将膨胀石墨材料球磨制成膨胀石墨纳米片,再通过微波水热法在膨胀石墨纳米片的表面负载UiO-66-NH-2,最后将制得物与六氯环三磷腈分散在四氢呋喃中进行反应接枝,反应生成物固液分离后即得球磨石墨纳米片负载UiO-66-NH-2接枝HCCP阻燃剂。本发明所制备得到的球磨石墨纳米片负载UiO-66-NH-2接枝HCCP阻燃剂具有较高阻燃性能,在阻燃方面有较好的应用前景,为MOFs材料提供了一种可行的阻燃应用方法。(The invention relates to a ball-milled graphite nanosheet loaded UiO-66-NH 2 A grafted HCCP flame retardant, a flame-retardant epoxy resin and a preparation method thereof. Ball-milled graphite nanosheet loaded UiO-66-NH 2 The grafted HCCP flame retardant is prepared by the following method: firstly, the expanded graphite material is ball-milled to prepare expanded graphite nano-sheets, and then UiO-66-NH is loaded on the surfaces of the expanded graphite nano-sheets by a microwave hydrothermal method 2 Finally, dispersing the prepared product and hexachlorocyclotriphosphazene in tetrahydrofuran for reaction grafting, and carrying out solid-liquid separation on the reaction product to obtain ball-milled graphite nanosheet loaded UiO-66-NH 2 Grafted HCCP flame retardant. The ball-milled graphite nanosheet loaded UiO-66-NH prepared by the invention 2 The grafted HCCP flame retardant has higher flame retardant performance and better application before flame retardantThe method provides a feasible flame-retardant application method for MOFs materials.)

1. A flame retardant is characterized by being prepared by the following method: firstly, the expanded graphite material is ball-milled to prepare expanded graphite nano-sheets, and then UiO-66-NH is loaded on the surfaces of the expanded graphite nano-sheets by a microwave hydrothermal method₂Finally, dispersing the prepared product and hexachlorocyclotriphosphazene in tetrahydrofuran for reaction grafting, and carrying out solid-liquid separation on the reaction product to obtain ball-milled graphite nanosheet loaded UiO-66-NH₂Grafted HCCP flame retardant.

2. The preparation method of the flame retardant is characterized by comprising the following steps of:

(a) adding 1 part of expanded graphite (in parts by weight, the same below) and 10 parts of deionized water into a reaction kettle of a ball mill, ball-milling for 48 hours at the rotating speed of 2500rpm, collecting a product, placing the product into a drying oven, and drying for 24 hours at the temperature of 60 ℃ to obtain expanded graphite nanosheets;

(b) reacting ZrCl₄Dissolving in dimethylformamide to obtain ZrCl with the concentration of 0.0066-0.0132 mol/L₄A solution; dissolving p-aminobenzoic acid in ZrCl₄Obtaining a para aminobenzoic acid solution with the concentration of 0.0059-0.0118 mol/L in the solution; glacial acetic acid accounting for 5.55-11.11% of the volume of the p-aminobenzoic acid solution and ZrCl₄Mixing 2.81-5.62% of expanded graphite nano-sheets by mass into a p-aminobenzoic acid solution, uniformly mixing, carrying out a synthesis reaction at 120-140 ℃ for 20-40 min, carrying out solid-liquid separation on the obtained reaction product, carrying out centrifugal washing on the separated solid matter with methanol for three times, carrying out centrifugal washing with dimethylformamide for three times, and then putting the solid matter into an oven to carry out vacuum drying at 80 ℃ for 12h to obtain the graphite flake supported UiO-66-NH₂；

(c) Dissolving hexachlorocyclotriphosphazene in tetrahydrofuran to obtain 0.0019 mol/L hexachlorocyclotriphosphazene solution, and adding graphite flake supported UiO-66-NH at a mass ratio of hexachlorocyclotriphosphazene to hexachlorocyclotriphosphazene of 1.36: 1₂Ultrasonic treatment is carried out for 2 hours at 40 ℃; performing microwave synthesis reaction at 80 ℃ for 30min, performing solid-liquid separation on the obtained reaction product, centrifugally washing the separated solid substance with methanol for three times, centrifugally washing with dimethylformamide for three times, and finally performing vacuum drying at 70 ℃ for 12h to obtain ball-milled graphite nanosheet loaded UiO-66-NH₂Grafted HCCP flame retardant.

3. Ball-milled graphite nanoplate-loaded UiO-66-NH as recited in claim 1₂The application of the grafted HCCP flame retardant in preparing flame-retardant materials.

4. Ball-milled graphite nanoplatelets loaded UiO-66-NH as in claim 3₂The application of the grafted HCCP flame retardant in the preparation of the flame-retardant material is characterized in that the ball-milled graphite nanosheet loaded UiO-66-NH₂The application of the grafted HCCP flame retardant in preparing flame-retardant epoxy resin.

5. The flame-retardant epoxy resin is characterized in that ball-milled graphite is added into the epoxy resinNanosheet-loaded UiO-66-NH₂Grafted HCCP flame retardant, wherein the ball-milled graphite nanosheet is loaded with UiO-66-NH₂The mass ratio of the grafted HCCP flame retardant to the epoxy resin is 1-4: 100;

the ball-milled graphite nanosheet loaded UiO-66-NH₂The grafted HCCP flame retardant is prepared by the following method: firstly, the expanded graphite material is ball-milled to prepare expanded graphite nano-sheets, and then UiO-66-NH is loaded on the surfaces of the expanded graphite nano-sheets by a microwave hydrothermal method₂Finally, dispersing the prepared product and hexachlorocyclotriphosphazene in tetrahydrofuran for reaction grafting, and carrying out solid-liquid separation on the reaction product to obtain ball-milled graphite nanosheet loaded UiO-66-NH₂Grafted HCCP flame retardant.

6. A preparation method of flame-retardant epoxy resin is characterized in that epoxy resin is heated and stirred, and then ball-milled graphite nanosheet loaded UiO-66-NH is added₂Grafted HCCP flame retardant and ball-milled graphite nanosheet loaded UiO-66-NH₂The mass ratio of the grafted HCCP flame retardant to the epoxy resin is 1-4: 100; adding m-phenylenediamine after uniformly stirring, wherein the mass ratio of the m-phenylenediamine to the epoxy resin is 10-14: 100, heating and curing after uniformly stirring, and cooling to obtain the flame-retardant epoxy resin;

the ball-milled graphite nanosheet loaded UiO-66-NH₂The grafted HCCP flame retardant is prepared by the following method: firstly, the expanded graphite material is ball-milled to prepare expanded graphite nano-sheets, and then UiO-66-NH is loaded on the surfaces of the expanded graphite nano-sheets by a microwave hydrothermal method₂Finally, dispersing the prepared product and hexachlorocyclotriphosphazene in tetrahydrofuran for reaction grafting, and carrying out solid-liquid separation on the reaction product to obtain ball-milled graphite nanosheet loaded UiO-66-NH₂Grafted HCCP flame retardant.

7. The preparation method of the flame-retardant epoxy resin as claimed in claim 6, wherein the epoxy resin is placed in a filter flask, heated and stirred for 20min at the temperature of 60 ℃ and the rotation speed of 180 rpm, and then 1-4 parts of ball-milled graphite nanosheet loaded UiO-66-NH is added₂Grafting HCCP flame retardant, stirring for 20min, and then adding 10-14 parts ofStirring the m-phenylenediamine for 20 min; taking out, pouring into a mold, standing at 60 deg.C for 20min in an oven with vacuum degree of 0.05 MPa, transferring into an oven with 80 deg.C, heating for 120 min, adjusting temperature to 150 deg.C, and heating and curing for 220 min; and cooling to room temperature, and taking out from the mold to obtain the flame-retardant epoxy resin.

Technical Field

The invention relates to a flame retardant, in particular to a flame retardant, flame-retardant epoxy resin and preparation methods thereof.

Background

Metal-organic framework (MOFs) materials are an organic-inorganic hybrid material and the number of reported species has increased rapidly in the last decade. MOFs are considered to be nano-porous materials with a variety of application prospects, such as electrode materials, drug sustained release, catalysis and other fields. At present, MOFs attract extensive attention in the flame retardant field due to the characteristics of ordered porous structures, active metal centers and the like, and metal sites contained in the MOFs and metal derivatives generated by degradation of the MOFs have excellent catalytic oxidation and catalytic carbon formation performances. MOFs materials can be broadly classified as: isotactic metal organic framework, zeolite imidazole acid ester framework, porous coordination net and the like. Meanwhile, in order to solve the problem of rapid batch production of the MOFs materials and meet the requirement of industrialization, various synthetic methods for the MOFs materials in different use scenes are also developed, for example: room temperature synthesis, hydrothermal method, ionic liquid method, microwave-assisted hydrothermal method, and the like.

Epoxy resin (EP) is an important thermosetting polymer, has excellent chemical resistance, low shrinkage and strong adhesion, and is widely used in the fields of composite material substrates, surface coatings, adhesives and the like. However, the high flammability of EP has greatly limited their applications. Among them, halogen-containing flame retardants are most effective, but are prohibited because they release a large amount of toxic gases such as HBr, HCl, dibenzo-p-dioxin, and dibenzofuran during combustion. Inorganic fillers such as aluminum hydroxide and magnesium hydroxide can improve the fire resistance of EP, but high amounts of fillers are necessary to achieve flame retardancy, which affects the mechanical properties.

Disclosure of Invention

One of the purposes of the invention is to provide a ball-milled graphite nanosheet loaded UiO-66-NH₂Grafted HCCP flame retardant and preparation method thereof, which is metal-organicThe application of the machine frame material in the flame retardant field provides a feasible treatment method.

The second purpose of the invention is to provide a flame-retardant epoxy resin and a preparation method thereof, so as to improve the flame-retardant property of the epoxy resin.

One of the objects of the invention is achieved by:

ball-milled graphite nanosheet loaded UiO-66-NH₂The grafted HCCP flame retardant is prepared by the following method: firstly, the expanded graphite material is ball-milled to prepare expanded graphite nano-sheets, and then UiO-66-NH is loaded on the surfaces of the expanded graphite nano-sheets by a microwave hydrothermal method₂Finally, dispersing the prepared product and Hexachlorocyclotriphosphazene (HCCP) in Tetrahydrofuran (THF) for reaction grafting, and carrying out solid-liquid separation on the reaction product to obtain ball-milled graphite nanosheet loaded UiO-66-NH₂Grafted HCCP flame retardant.

II, carrying UiO-66-NH on ball-milled graphite nano-sheet₂The preparation method of the grafted HCCP flame retardant comprises the following steps:

(a) adding 1 part of expanded graphite (in parts by weight, the same below) and 10 parts of deionized water into a reaction kettle of a ball mill, ball-milling for 48 hours at the rotating speed of 2500rpm, collecting a product, placing the product in a drying oven, and drying for 24 hours at the temperature of 60 ℃ to obtain expanded graphite nano sheets, which are marked as GnPs;

(b) reacting ZrCl₄Dissolving in dimethylformamide to obtain ZrCl with the concentration of 0.0066-0.0132 mol/L₄A solution; dissolving p-aminobenzoic acid in ZrCl₄Obtaining a para aminobenzoic acid solution with the concentration of 0.0059-0.0118 mol/L in the solution; glacial acetic acid accounting for 5.55-11.11% of the volume of the p-aminobenzoic acid solution and ZrCl₄Mixing 2.81-5.62% of expanded graphite nano-sheets by mass into a p-aminobenzoic acid solution, uniformly mixing, carrying out a synthesis reaction at 120-140 ℃ for 20-40 min, carrying out solid-liquid separation on the obtained reaction product, carrying out centrifugal washing on the separated solid matter with methanol for three times, carrying out centrifugal washing with dimethylformamide for three times, and then putting the solid matter into an oven to carry out vacuum drying at 80 ℃ for 12h to obtain the graphite flake supported UiO-66-NH₂And is marked as G-U;

(c) dissolving Hexachlorocyclotriphosphazene (HCCP)Obtaining hexachlorocyclotriphosphazene solution with the concentration of 0.0019 mol/L in Tetrahydrofuran (THF), adding graphite flake supported UiO-66-NH with the mass ratio of hexachlorocyclotriphosphazene to hexachlorocyclotriphosphazene of 1.36: 1₂Ultrasonic treatment is carried out for 2 hours at 40 ℃; performing microwave synthesis reaction at 80 ℃ for 30min, performing solid-liquid separation on the obtained reaction product, centrifugally washing the separated solid substance with methanol for three times, centrifugally washing with dimethylformamide for three times, and finally performing vacuum drying at 70 ℃ for 12h to obtain ball-milled graphite nanosheet loaded UiO-66-NH₂Grafted HCCP flame retardant, noted G-U-H.

Thirdly, the ball-milled graphite nanosheet loaded UiO-66-NH₂The application of the grafted HCCP flame retardant in preparing materials with flame retardant property.

Preferably, the ball-milled graphite nanosheets are loaded with UiO-66-NH₂The application of the grafted HCCP flame retardant in preparing flame-retardant epoxy resin.

The method comprises the steps of taking expanded graphite, 2-amino terephthalic acid, zirconium tetrachloride and hexachlorocyclotriphosphazene as raw materials, preparing the expanded graphite nanosheet by adopting wet ball milling, and loading UiO-66-NH on the surface of the expanded graphite nanosheet by using a microwave hydrothermal method₂Finally grafting with Hexachlorocyclotriphosphazene (HCCP) to obtain ball-milled graphite nano-sheet loaded UiO-66-NH₂Grafted HCCP flame retardant. According to the invention, the MOFs material and the traditional phosphazene flame retardant are combined, so that a feasible flame retardant treatment method is provided for the MOFs material, the application field of the MOFs material is expanded, and the prepared flame retardant has high flame retardant property and good application prospect in the flame retardant aspect.

The second purpose of the invention is realized by the following steps:

a fire-retardant epoxy resin is prepared by adding ball-milled graphite nanosheet loaded UiO-66-NH into epoxy resin₂Grafted HCCP flame retardant, wherein the ball-milled graphite nanosheet is loaded with UiO-66-NH₂The mass ratio of the grafted HCCP flame retardant to the epoxy resin is 1-4: 100;

the ball-milled graphite nanosheet loaded UiO-66-NH₂The grafted HCCP flame retardant is prepared by the following method: firstly, the expanded graphite material is ball milled to prepare expanded graphite nano-sheetsAnd loading UiO-66-NH on the surface of the expanded graphite nano-sheet by a microwave hydrothermal method₂Finally, dispersing the prepared product and Hexachlorocyclotriphosphazene (HCCP) in Tetrahydrofuran (THF) for reaction grafting, and carrying out solid-liquid separation on the reaction product to obtain ball-milled graphite nanosheet loaded UiO-66-NH₂Grafted HCCP flame retardant.

Secondly, a preparation method of the flame-retardant epoxy resin, heating and stirring the epoxy resin, and adding the ball-milled graphite nano-sheet loaded UiO-66-NH₂Grafted HCCP flame retardant and ball-milled graphite nanosheet loaded UiO-66-NH₂The mass ratio of the grafted HCCP flame retardant to the epoxy resin is 1-4: 100; adding m-phenylenediamine after uniformly stirring, wherein the mass ratio of the m-phenylenediamine to the epoxy resin is 10-14: 100, heating and curing after uniformly stirring, and cooling to obtain the flame-retardant epoxy resin;

the ball-milled graphite nanosheet loaded UiO-66-NH₂The grafted HCCP flame retardant is prepared by the following method: firstly, the expanded graphite material is ball-milled to prepare expanded graphite nano-sheets, and then UiO-66-NH is loaded on the surfaces of the expanded graphite nano-sheets by a microwave hydrothermal method₂Finally, dispersing the prepared product and Hexachlorocyclotriphosphazene (HCCP) in Tetrahydrofuran (THF) for reaction grafting, and carrying out solid-liquid separation on the reaction product to obtain ball-milled graphite nanosheet loaded UiO-66-NH₂Grafted HCCP flame retardant.

Specifically, the preparation method of the flame-retardant epoxy resin comprises the steps of placing 100 parts (by weight, the same below) of epoxy resin in a filter flask, heating and stirring for 20min at the temperature of 60 ℃ and the rotation speed of 180 rpm, and then adding 1-4 parts of ball-milled graphite nanosheet loaded UiO-66-NH₂Grafting an HCCP flame retardant, stirring for 20min, adding 10-14 parts of m-phenylenediamine, and stirring for 20 min; taking out, pouring into a mold, standing at 60 deg.C for 20min in an oven with vacuum degree of 0.05 MPa, transferring into an oven with 80 deg.C, heating for 120 min, adjusting temperature to 150 deg.C, and heating and curing for 220 min; and cooling to room temperature, and taking out from the mold to obtain the flame-retardant epoxy resin.

The ball-milled graphite nanosheet loaded UiO-66-NH prepared by the invention₂The grafted HCCP flame retardant can be used aloneThe flame retardant is added into a material needing to improve the flame retardant performance to prepare a corresponding flame retardant material, and when the flame retardant is added into epoxy resin, the flame retardant effect of the obtained flame retardant epoxy resin is greatly improved, so that the flame retardant epoxy resin has a wide industrial application prospect.

Drawings

FIG. 1 is a Thermogravimetric (TG) plot of the hexachlorocyclotriphosphazene purchased in example 1.

FIG. 2 is a Thermogravimetric (TG) plot of the G-U-H prepared in example 1.

FIG. 3 is an SEM image of G-U-H, where a is an SEM image of expanded graphite nanoplatelets; b is UiO-66-NH₂SEM image of (a); c is an SEM image of G-U; d is an SEM image of G-U-H; e is the mapping graph of G-U-H; f is the elementary energy spectrum of G-U-H.

FIG. 4 is a graph of the Heat Release Rate (HRR) in cone calorimetry for the epoxy resin prepared in comparative example 1.

FIG. 5 is a graph of the Heat Release Rate (HRR) in cone calorimetry for the epoxy composite prepared in example 2.

FIG. 6 is a graph of the Heat Release Rate (HRR) in cone calorimetry for the epoxy composite prepared in example 3.

FIG. 7 is a graph of the Heat Release Rate (HRR) in cone calorimetry for the epoxy composite prepared in example 4.

FIG. 8 is a graph of the Heat Release Rate (HRR) in cone calorimetry for the epoxy composite prepared in example 5.

Detailed Description

The invention is further illustrated by the following examples, which are given by way of illustration only and are not intended to limit the scope of the invention in any way.

The procedures and methods not described in detail in the examples of the present invention are conventional methods well known in the art, and the reagents used in the examples are all analytically or chemically pure and are either commercially available or prepared by methods well known to those of ordinary skill in the art. The following examples all achieve the objects of the present invention.

The hexachlorocyclotriphosphazene used in the following examples was analytically pure and 99.8% pure, and was produced by Zibo blue printing chemical Co., Ltd.

Example 1:

1 part of expanded graphite and 10 parts of deionized water were added to the reaction kettle of the ball mill by wet ball milling and mechanically stripped at 2500rpm for 48 hours, then the product was collected and placed in an oven to dry at 60 ℃ for 24 hours, denoted as GnPs.

Reacting ZrCl₄Dissolving in dimethyl formamide (DMF) to obtain ZrCl with the concentration of 0.0066-0.0132 mol/L₄A solution; dissolving p-aminobenzoic acid in ZrCl₄The dimethylformamide solution is added to obtain a para aminobenzoic acid solution with the concentration of 0.0059-0.0118 mol/L, and glacial acetic acid (HAc) accounting for 5.55-11.11% of the volume of the para aminobenzoic acid solution is added to the para aminobenzoic acid solution to control UiO-66NH₂The growth morphology of (2); finally adding ZrCl₄And (3) ultrasonically dispersing the expanded graphite nanosheets with the mass of 2.81-5.62%, sealing and ultrasonically treating for 10min for later use. Setting the reaction conditions of the microwave synthesizer to be 120-140 ℃, setting the reaction time to be 20-40 min, setting the heating power to be 70W, and controlling the heating rate. Performing microwave synthesis reaction on the ultrasonically dispersed solution by using a microwave synthesizer; and collecting a reactant synthesized by the microwave, carrying out solid-liquid separation, respectively carrying out centrifugal washing on the separated solid substance for three times by using methanol and DMF (dimethyl formamide), and finally drying in a vacuum oven at 80 ℃ for 12 hours, wherein the product is marked as G-U. Pure UiO-66-NH2 was synthesized by a similar procedure without the addition of GnPs.

Dissolving Hexachlorocyclotriphosphazene (HCCP) in Tetrahydrofuran (THF) to obtain 0.0019 mol/L hexachlorocyclotriphosphazene solution, and adding graphite flake-loaded UiO-66-NH (NH-loaded) at a mass ratio of hexachlorocyclotriphosphazene to hexachlorocyclotriphosphazene of 1.36: 1₂. The reaction conditions of the microwave synthesizer were set at 80 ℃ for 30 min. Performing microwave synthesis reaction on the ultrasonically dispersed solution by using a microwave synthesizer; collecting the reactant synthesized by the microwave, carrying out solid-liquid separation, centrifugally washing the separated solid by methanol and DMF (dimethyl formamide) for three times respectively, and drying in vacuum at 70 ℃ for 12 hours to obtain ball-milled graphite nanosheet loaded UiO-66-NH₂Grafted HCCP flame retardant, noted G-U-H.

Produced by NETZSCH company in GermanySTA449C type thermogravimetric pair GnPs, UiO-66-NH₂G-U-H and HCCP, and T5% is the temperature corresponding to 5% weight loss of the sample, and the obtained results are shown in Table 1.

Table 1: comparison of the thermal stability of the products of the invention

As is clear from Table 1, Hexachlorocyclotriphosphazene (HCCP) has an initial decomposition temperature of 125.6 ℃ and cannot be used alone as a flame retardant in EP. Ball-milled graphite nanosheet loaded UiO-66-NH₂The initial decomposition temperature of the grafted HCCP flame retardant (G-U-H) is above 230 ℃, and the grafted HCCP flame retardant can be independently used as a flame retardant in EP.

The test was carried out using an electron scanning electron microscope (SEM, JSM, JEOL Ltd., Japan) and a transmission electron microscope-energy dispersive X-ray analysis (TEM-EDX, FEI Tecnai G2F 20 Corporation, USA). The resulting correlation data are shown in fig. 2.

From FIG. 3, UiO-66-NH can be seen₂The nano particles are octahedral and about 500nm in size, smooth in surface, uniform in particle size and free of agglomeration. FIG. 3c is an SEM image of G-U showing dense UiO-66-NH₂The nanoparticles were uniformly distributed on the surface of GnPs, indicating that GnPs provide a platform for nucleation and growth of MOF nanoparticles. As can be seen from FIG. 3d, the-NH-due to the activity of the MOFs particles₂And the hydroxyl groups on the GnPs react with the P-Cl bonds of the HCCP, so that the MOFs nanoparticles have slight agglomeration phenomena with each other and with the GnPs. The EDX-characterized elemental spectra (fig. 3 f) and mapping images (fig. 3 e) show that the P and N elements are uniformly distributed in the G-U-H product and the presence of Cl elements is not detected.

Comparative example 1:

weighing 120g of epoxy resin, placing the epoxy resin in a clean filter flask, heating and stirring the epoxy resin for 20min at 60 ℃ and 180 rpm, then adding 13.2 g of curing agent m-phenylenediamine, and stirring the epoxy resin for 20min to ensure that the m-phenylenediamine is uniformly dispersed; pouring the mold, placing in an oven with a vacuum degree of 0.05 MPa at 60 ℃ for 20min, transferring to an oven with a vacuum degree of 80 ℃, heating for 120 min, adjusting the temperature to 150 ℃, and heating and curing for 220 min. After cooling to room temperature, the specimens were removed to give EP material.

Example 2:

weighing 120g of epoxy resin in a clean filter flask, heating and stirring for 20min at 60 ℃ and 180 rpm, and then adding 1.2g of the ball-milled graphite nanosheet loaded UiO-66-NH prepared in example 1₂Grafting HCCP flame retardant, then adding 13.2 g of m-phenylenediamine, stirring for 20min, and ensuring that the m-phenylenediamine serving as a curing agent is uniformly dispersed; pouring into a mold, standing at 60 deg.C for 20min in an oven with vacuum degree of 0.05 MPa, transferring into an oven with 80 deg.C, heating for 120 min, adjusting temperature to 150 deg.C, and heating and curing for 220 min. And cooling to room temperature, and taking out the sample strip from the mold to obtain the flame-retardant EP material.

Example 3:

according to the process conditions of the example 1, 2.4g of the ball-milled graphite nanosheet supported UiO-66-NH prepared in the example 1 is added into epoxy resin respectively₂And grafting HCCP flame retardant to prepare the corresponding flame-retardant EP material.

Example 4:

according to the process conditions of the example 1, 3.6g of the ball-milled graphite nanosheet supported UiO-66-NH prepared in the example 1 is added into epoxy resin respectively₂And grafting HCCP flame retardant to prepare the corresponding flame-retardant EP material.

Example 5:

according to the process conditions of the example 1, 4.8g of the ball-milled graphite nanosheet supported UiO-66-NH prepared in the example 1 is added into epoxy resin respectively₂And grafting HCCP flame retardant to prepare the corresponding flame-retardant EP material.

The experimental method comprises the following steps:

limiting Oxygen Index (LOI): the minimum oxygen percentage required to maintain combustion of the sample material in the nitrogen-oxygen mixture is used to characterize the flame retardant effect of the flame retardant. The sample size was 140mm by 6mm by 3mm as measured by ASTM D2863-2000 using HC-2 oxygen index apparatus (Nanjing Jiangning Analyzer Co.).

CONE Calorimetry (CONE): cone calorimetry was measured using an icone plus (FTT Co., UK)) Sample size 100mm X3 mm, irradiation power 50Kw/m²。

The detection results are as follows:

table 2: effect of the inventive products on the flame retardancy of flame-retardant EP

As can be seen from Table 2, the limiting oxygen index of the pure epoxy resin is 24.0%, and it is a flammable product. After 1.2G, 2.4G, 3.6G and 4.8G of G-U-H flame retardant was added to the epoxy resin, the oxygen index increased to 25.2%, 25.7%, 27.3% and 27.1%, respectively.

As can be seen from the Heat Release Rate (HRR) graphs of the epoxy resin composite materials prepared in the comparative example 1 and the examples 2, 3, 4 and 5 shown in the figures 4-8 in the cone calorimetry, the peak value (PHRR) of the heat release rate of the epoxy resin reaches 1232.3 Kw/m²Higher heat release rate; as is apparent from FIGS. 4, 5, 6 and 7, the PHRR after adding 1.2g, 2.4g and 3.6g of the flame retardant prepared in example 2 was reduced to 1057.0, 860.0, 823.1 and 1087.6 Kw/m, respectively²The reduction is 14.2%, 30.20%, 33.21% and 11.74% respectively compared with that of epoxy resin.