CN114479617B - Preparation method and application of Gr/BPA@Si nanometer hybrid material and fireproof coating - Google Patents

Abstract

The embodiment of the invention provides a preparation method and application of Gr/BPA@Si nanometer hybrid material and fireproof paint, comprising the following steps: s1, dispersing BPA in a solvent to obtain a first dispersion liquid; s2, dispersing Gr in the first dispersion liquid to obtain a second dispersion liquid; s3, dripping the oligomeric silsesquioxane solution into the second dispersion liquid under the stirring state for reaction, and treating to obtain the Gr/BPA@Si nano hybrid material. According to the embodiment of the invention, the carbon layer strength, oxidation resistance and foaming uniformity of the expansion type fireproof coating are improved through the fireproof coating obtained by uniformly mixing the base material and the Gr/BPA@Si nanometer hybrid material; the fireproof paint provided by the embodiment of the invention overcomes the dangerous characteristics of low strength, poor oxidation resistance and uneven expansion of the existing aqueous epoxy resin carbon layer, and the obtained nano fireproof paint has the characteristics of high strength, strong oxidation resistance and even expansion of the carbon layer, and the fireproof performance is greatly improved.

Description

Preparation method and application of Gr/BPA@Si nanometer hybrid material and fireproof coating

Technical Field

The embodiment of the invention relates to a preparation method and application of Gr/BPA@Si nanometer hybrid material and fireproof paint.

Background

Steel structures are widely used in various building structures, and are a main form of modern buildings. Although steel structures have the advantages of light weight and high strength, poor fire resistance is one of the prominent disadvantages. In case of fire in the building, the steel structure can rapidly rise to a destruction temperature of 500 ℃ and collapse. The fire-resistant time of the steel structure is only 15min without protection, which is not beneficial to people evacuation and fire extinguishment in fire disaster. In this case, good protection must be taken for the steel structure to address the potential risk of steel fires.

The expansion type fireproof paint has the advantages of simple structure, light weight, long fireproof time, no limitation of the geometric shape of the steel structure, and good economical efficiency and practicability. In recent years, waterborne epoxy intumescent fire-retardant coatings have received increasing attention for their excellent environmental protection properties, which consist mainly of a resin matrix, a flame retardant system (acid source, carbon source, blowing agent) and a filler. In the event of a fire, the coating will foam, carbonize and form a spongy carbon layer, providing protection to the substrate. However, the low strength, poor oxidation resistance and uneven foaming of the char layer are major dangerous disadvantages of waterborne epoxy intumescent coatings, thus limiting their application in fields where fire safety is critical.

Disclosure of Invention

The embodiment of the invention provides a Gr/BPA@Si nano hybrid material and a preparation method and application of a fireproof coating, so as to improve the strength, oxidation resistance and foaming uniformity of a carbon layer of an intumescent fireproof coating.

The embodiment of the invention is realized by the following technical scheme:

in a first aspect, an embodiment of the present invention provides a method for preparing a Gr/bpa@si nanohybrid material, including:

s1, dispersing BPA in a solvent to obtain a first dispersion liquid;

s2, dispersing Gr in the first dispersion liquid to obtain a second dispersion liquid;

s3, dripping the oligomeric silsesquioxane solution into the second dispersion liquid under the stirring state for reaction, and treating to obtain the Gr/BPA@Si nano hybrid material.

Further, the mass ratio of BPA to the oligomeric silsesquioxane is 1:0.4-0.5.

Further, the reaction temperature of the S2 is 75-85 ℃ and the reaction time is 45-55h; the solvent is absolute ethyl alcohol; the oligomeric silsesquioxane solution is an ethanol solution of oligomeric silsesquioxane.

Further, the preparation method of the BPA comprises the following steps:

t1, uniformly mixing hexagonal boron nitride, aniline monomer and water to obtain suspension;

and T2, dropwise adding an ammonium persulfate hydrochloric acid aqueous solution into the suspension, and reacting to obtain BPA.

Further, the mass ratio of the aniline monomer to the ammonium persulfate is 1:2.5-3.5; the mass ratio of the BPA to the hexagonal boron nitride is 1:0.05-0.15.

Further, in the hydrochloric acid aqueous solution of ammonium persulfate, the concentration of HCl in the hydrochloric acid aqueous solution is 0.05mol/L; the reaction temperature in the T2 is 0-5 ℃ and the reaction time is 6-10h.

In a second aspect, an embodiment of the present invention provides a method for preparing a fire retardant coating, including: uniformly mixing a base material with the Gr/BPA@Si nano hybrid material to obtain the fireproof coating; wherein the Gr/BPA@Si nano hybrid material accounts for 1.5% -3.5% of the total weight of the fireproof coating.

Further, uniformly mixing the base material with the Gr/BPA@Si nano hybrid material to obtain the fireproof coating; comprising the following steps:

uniformly mixing a base material, a defoaming agent and the Gr/BPA@Si nano hybrid material to obtain the fireproof coating;

wherein the defoamer accounts for 0.5 to 1.5 percent of the total weight of the fireproof coating.

Further, the preparation method of the base material comprises the following steps:

uniformly mixing epoxy resin, a curing agent and an expanding agent to obtain a uniformly mixed base material; wherein, the mass ratio of the epoxy resin to the curing agent is 2:1, a step of; the mass ratio of the epoxy resin to the expanding agent is 2-2.5:1 to 1.5; the expanding agent comprises the following components in percentage by mass of 5.5-6.5:2.5-3.5: melamine polyphosphate, dipentaerythritol and melamine in the range of 1 to 1.5.

In a third aspect, embodiments of the present invention provide use of the Gr/bpa@si nanohybrid material or the fire protection material in fire protection of steel structures.

Compared with the prior art, the embodiment of the invention has the following advantages and beneficial effects:

according to the preparation method and the application of the Gr/BPA@Si nano hybrid material and the fireproof coating, the carbon layer strength, the oxidation resistance and the foaming uniformity of the intumescent fireproof coating are improved through the fireproof coating obtained by uniformly mixing a base material with the Gr/BPA@Si nano hybrid material; the fireproof paint provided by the embodiment of the invention overcomes the dangerous characteristics of low strength, poor oxidation resistance and uneven expansion of the existing aqueous epoxy resin carbon layer, and the obtained nano fireproof paint has the characteristics of high strength, strong oxidation resistance and even expansion of the carbon layer, and the fireproof performance is greatly improved.

Drawings

In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings that are needed in the examples will be briefly described below, it being understood that the following drawings only illustrate some examples of the present invention and therefore should not be considered as limiting the scope, and that other related drawings may be obtained from these drawings without inventive effort for a person skilled in the art.

FIG. 1 is an X-ray diffraction pattern of Gr, BN, BPA, gr/BPA, gr/BPA@Si.

FIG. 2 is a transmission electron microscope image of BN, BPA, gr/BPA, gr/BPA@Si, wherein A is h-BN, B is BPA, C is Gr/BPA, and D is Gr/BPA@Si.

FIG. 3 is a scanning electron microscope image of the cross section of an EP, BN/EP, BPA/EP, gr/BPA@Si/EP coating, wherein A is EP, B is BN/EP, C is BPA/EP, D is Gr/BPA/EP, E is Gr/BPA@Si/EP.

FIG. 4 is a graph showing the temperature profile of the back surface of a steel sheet after the large plate test.

Fig. 5 shows the results of cone calorimeter measurements, where a is the average Heat Release Rate (HRR), B is the total heat release rate (THR), C is the average smoke release (SPR), and D is the total smoke release (TSP).

FIG. 6 is a scanning electron microscope image of the morphology of the coating and the char layer after cone calorimeter testing, wherein A is EP, B is BN/EP, C is BPA/EP, D is Gr/BPA/EP, and E is Gr/BPA@Si/EP.

Detailed Description

For the purpose of making apparent the objects, technical solutions and advantages of the present invention, the present invention will be further described in detail with reference to the following examples and the accompanying drawings, wherein the exemplary embodiments of the present invention and the descriptions thereof are for illustrating the present invention only and are not to be construed as limiting the present invention.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that: no such specific details are necessary to practice the invention. In other instances, well-known structures, circuits, materials, or methods have not been described in detail in order not to obscure the invention.

Throughout the specification, references to "one embodiment," "an embodiment," "one example," or "an example" mean: a particular feature, structure, or characteristic described in connection with the embodiment or example is included within at least one embodiment of the invention. Thus, the appearances of the phrases "in one embodiment," "in an example," or "in an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable combination and/or sub-combination in one or more embodiments or examples. Moreover, those of ordinary skill in the art will appreciate that the illustrations provided herein are for illustrative purposes and that the illustrations are not necessarily drawn to scale. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

In the description of the present invention, the terms "front", "rear", "left", "right", "upper", "lower", "vertical", "horizontal", "high", "low", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, merely to facilitate description of the present invention and simplify description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the scope of the present invention.

Examples

In order to improve the strength, oxidation resistance and foaming uniformity of a carbon layer of an intumescent fire retardant coating, in a first aspect, an embodiment of the invention provides a preparation method of a Gr/BPA@Si nano hybrid material, which comprises the following steps: s1, dispersing BPA in a solvent to obtain a first dispersion liquid; s2, dispersing Gr in the first dispersion liquid to obtain a second dispersion liquid; s3, dripping the oligomeric silsesquioxane solution into the second dispersion liquid under the stirring state for reaction, and treating to obtain the Gr/BPA@Si nano hybrid material.

Further, the mass ratio of BPA to the oligomeric silsesquioxane is 1:0.4-0.5.

Further, the reaction temperature of the S2 is 75-85 ℃ and the reaction time is 45-55h; the solvent is absolute ethyl alcohol; the oligomeric silsesquioxane solution is an ethanol solution of oligomeric silsesquioxane.

Further, the preparation method of the BPA comprises the following steps:

t1, uniformly mixing hexagonal boron nitride, aniline monomer and water to obtain suspension;

and T2, dropwise adding an ammonium persulfate hydrochloric acid aqueous solution into the suspension, and reacting to obtain BPA.

Further, the mass ratio of the aniline monomer to the ammonium persulfate is 1:2.5-3.5; the mass ratio of the BPA to the hexagonal boron nitride is 1:0.05-0.15.

Further, in the hydrochloric acid aqueous solution of ammonium persulfate, the concentration of HCl in the hydrochloric acid aqueous solution is 0.05mol/L; the reaction temperature in the T2 is 0-5 ℃ and the reaction time is 6-10h.

In a second aspect, an embodiment of the present invention provides a method for preparing a fire retardant coating, including: uniformly mixing a base material with the Gr/BPA@Si nano hybrid material to obtain the fireproof coating; wherein the Gr/BPA@Si nano hybrid material accounts for 1.5% -3.5% of the total weight of the fireproof coating.

Therefore, the carbon layer strength, oxidation resistance and foaming uniformity of the expansion type fireproof coating are improved through the fireproof coating obtained by uniformly mixing the base material and the Gr/BPA@Si nanometer hybrid material; the fireproof paint provided by the embodiment of the invention overcomes the dangerous characteristics of low strength, poor oxidation resistance and uneven expansion of the existing aqueous epoxy resin carbon layer, and the obtained nano fireproof paint has the characteristics of high strength, strong oxidation resistance and even expansion of the carbon layer, and the fireproof performance is greatly improved.

Further, uniformly mixing the base material with the Gr/BPA@Si nano hybrid material to obtain the fireproof coating; comprising the following steps:

uniformly mixing a base material, a defoaming agent and the Gr/BPA@Si nano hybrid material to obtain the fireproof coating;

wherein the defoamer accounts for 0.5 to 1.5 percent of the total weight of the fireproof coating.

Further, the preparation method of the base material comprises the following steps:

uniformly mixing epoxy resin, a curing agent and an expanding agent to obtain a uniformly mixed base material; wherein, the mass ratio of the epoxy resin to the curing agent is 2:1, a step of; the mass ratio of the epoxy resin to the expanding agent is 2-2.5:1 to 1.5; the expanding agent comprises the following components in percentage by mass of 5.5-6.5:2.5-3.5: melamine polyphosphate, dipentaerythritol and melamine in the range of 1 to 1.5.

In a third aspect, embodiments of the present invention provide use of the Gr/bpa@si nanohybrid material or the fire protection material in fire protection of steel structures.

Example 1

A preparation method of Gr/BPA@Si nanometer hybrid material comprises the following steps: s1, dispersing BPA in absolute ethyl alcohol to obtain a first dispersion liquid; s2, dispersing Gr in the first dispersion liquid to obtain a second dispersion liquid; s3, dripping an ethanol solution of the oligomeric silsesquioxane into the second dispersion liquid under the stirring state, reacting for 45 hours at the temperature of 75 ℃, and treating to obtain the Gr/BPA@Si nano hybrid material; the mass ratio of BPA to oligomeric silsesquioxane was 1:0.4.

The preparation method of the BPA comprises the following steps: t1, uniformly mixing hexagonal boron nitride, aniline monomer and water to obtain suspension; t2. Dropwise adding ammonium persulfate aqueous hydrochloric acid solution (HCl concentration in the aqueous hydrochloric acid solution is 0.05 mol/L) into the suspension, and reacting at 0 ℃ for 6 hours to obtain BPA; the mass ratio of the aniline monomer to the ammonium persulfate is 1:2.5; the mass ratio of BPA to hexagonal boron nitride is 1:0.05.

The preparation method of the fireproof paint comprises the following steps: uniformly mixing the base material with Gr/BPA@Si nano hybrid material accounting for 1.5% of the total weight of the fireproof coating to obtain the fireproof coating; the preparation method of the base material comprises the following steps: uniformly mixing epoxy resin, a curing agent and an expanding agent to obtain a uniformly mixed base material; wherein, the mass ratio of the epoxy resin to the curing agent is 2:1, a step of; the mass ratio of the epoxy resin to the expanding agent is 2:1, a step of; the expanding agent comprises the following components in percentage by mass of 5.5:2.5:1, dipentaerythritol and melamine.

Example 2

A preparation method of Gr/BPA@Si nanometer hybrid material comprises the following steps: s1, dispersing BPA in absolute ethyl alcohol to obtain a first dispersion liquid; s2, dispersing Gr in the first dispersion liquid to obtain a second dispersion liquid; s3, dripping an ethanol solution of the oligomeric silsesquioxane into the second dispersion liquid under the stirring state, reacting for 55 hours at the temperature of 85 ℃, and obtaining the Gr/BPA@Si nano hybrid material after treatment; the mass ratio of BPA to oligomeric silsesquioxane was 1:0.5.

The preparation method of the BPA comprises the following steps: t1, uniformly mixing hexagonal boron nitride, aniline monomer and water to obtain suspension; t2. Dropwise adding ammonium persulfate aqueous hydrochloric acid solution (HCl concentration in the aqueous hydrochloric acid solution is 0.05 mol/L) into the suspension, and reacting at 5 ℃ for 6 hours to obtain BPA; the mass ratio of the aniline monomer to the ammonium persulfate is 1:3.5; the mass ratio of BPA to hexagonal boron nitride is 1:0.15.

The preparation method of the fireproof paint comprises the following steps: uniformly mixing a base material, a defoaming agent accounting for 1.5% of the total weight of the fireproof coating and Gr/BPA@Si nano hybrid material accounting for 3.5% of the total weight of the fireproof coating to obtain the fireproof coating; the preparation method of the base material comprises the following steps: uniformly mixing epoxy resin, a curing agent and an expanding agent to obtain a uniformly mixed base material; wherein, the mass ratio of the epoxy resin to the curing agent is 2:1, a step of; the mass ratio of the epoxy resin to the expanding agent is 2.5:1.5; the expanding agent comprises the following components in percentage by mass: 3.5: melamine polyphosphate, dipentaerythritol and melamine of 1.5.

Example 3

A preparation method of Gr/BPA@Si nanometer hybrid material comprises the following steps: s1, dispersing BPA in absolute ethyl alcohol to obtain a first dispersion liquid; s2, dispersing Gr in the first dispersion liquid to obtain a second dispersion liquid; s3, dripping an ethanol solution of the oligomeric silsesquioxane into the second dispersion liquid under the stirring state, reacting for 48 hours at the temperature of 80 ℃, and obtaining the Gr/BPA@Si nano hybrid material after treatment; the mass ratio of BPA to oligomeric silsesquioxane was 1:0.45.

The preparation method of the BPA comprises the following steps: t1, uniformly mixing hexagonal boron nitride, aniline monomer and water to obtain suspension; t2. Dropwise adding ammonium persulfate aqueous hydrochloric acid solution (HCl concentration in the aqueous hydrochloric acid solution is 0.05 mol/L) into the suspension, and reacting at 3 ℃ for 8 hours to obtain BPA; the mass ratio of the aniline monomer to the ammonium persulfate is 1:3; the mass ratio of BPA to hexagonal boron nitride is 1:0.1.

The preparation method of the fireproof paint comprises the following steps: uniformly mixing a base material, a defoaming agent accounting for 1% of the total weight of the fireproof coating and Gr/BPA@Si nano hybrid material accounting for 3% of the total weight of the fireproof coating to obtain the fireproof coating; the preparation method of the base material comprises the following steps: uniformly mixing epoxy resin, a curing agent and an expanding agent to obtain a uniformly mixed base material; wherein, the mass ratio of the epoxy resin to the curing agent is 2:1, a step of; the mass ratio of the epoxy resin to the expanding agent is 2.1:1.2; the expanding agent comprises the following components in percentage by mass: 3: melamine polyphosphate, dipentaerythritol and melamine of 1.2.

Example 4

A preparation method of a high-temperature-resistant nano Gr/BPA@Si aqueous epoxy resin intumescent fire-retardant coating specifically comprises the following steps:

s1: 47.97g of epoxy resin, 24.03g of curing agent and 25g of expansion system (15 g of melamine polyphosphate, 7.5g of dipentaerythritol and 2.5g of melamine) are weighed, 1g of defoamer is mechanically stirred for 3 hours at 300r/min, and then stirred for 2 hours at 60r/min, so as to obtain a uniformly mixed base material; wherein the short chain fatty amine curing agent is Ethylenediamine (EDA), diethylenetriamine (DTA) or triethylenetetramine (TTA).

S2: preparation of two-dimensional BPA nano hybrid material: into a 250mL three-necked round bottom flask, 0.233g of hexagonal boron nitride (h-BN), 60mL of distilled water, and 1.86g of aniline monomer were charged, equipped with a reflux condenser, a mechanical stirrer, and a dropping funnel, to form a uniform suspension. Then, 40mL of an aqueous solution of 0.05mol/LHCl (0.073 g) containing 5.477g of ammonium persulfate (NH 4) 2S2O8 (APS) was added dropwise to the prepared suspension in an ice bath; the solution mixture was continued at 0-5℃for 8 hours to complete the oxidative polymerization process. Finally, BPA is obtained by washing with ethanol, water and vacuum drying at 80℃for 24 h.

S3: preparation of two-dimensional Gr/BPA@Si nanometer hybrid material: 1g of BPA was sonicated into 100 ml of absolute ethanol and then 0.1. 0.1gGr powder was mixed into the BPA dispersion solution under intense sonication (sonication for an additional 1 h). Subsequently, the above dispersion was transferred to a 250mL three-necked round bottom flask, and 5mL of a uniform ethanol solution of oligomeric silsesquioxane (EPOSS) was slowly dropped into the above reactor (0.09 g/mL) with vigorous stirring, after which the reaction mixture was heated to 80 ℃ with gentle stirring for 48 hours, and then the mixture obtained by the above reaction was centrifuged and washed 3 times to remove unreacted EPOSS. Finally, the final product prepared was dried under vacuum at 60℃for 20 hours to give Gr/BPA@Si hybrid.

S4: preparation of high-temperature-resistant nano Gr/BPA@Si aqueous epoxy resin intumescent fire-retardant coating: 97g of base material, 2g of modified Gr/BPA@Si nano hybrid material and 1g of defoaming agent are weighed, mixed, mechanically stirred and dispersed for 5 hours to form a uniform dispersion system, then the uniform dispersion system is coated on the surface of a rectangular steel sheet, and cured for 7 days at normal temperature after the coating is finished, and baked for 3 days at 40 ℃ to obtain the high-temperature-resistant nano Gr/BPA@Si intumescent fire retardant coating.

The example shows the experimental analysis results related to the preparation method of the high-temperature-resistant nano Gr/BPA@Si aqueous epoxy resin intumescent fire retardant coating.

BN, BPA, gr/BPA and Gr/BPA@Si are respectively mixed with epoxy resin, and dispersed for 5 hours by mechanical stirring, BN/EP, BPA/EP, gr/BPA/EP and Gr/BPA@Si coatings with the content of BN, BPA, gr/BPA and Gr/BPA@Si being 2wt% are respectively prepared, and are respectively coated on a base steel sheet (P110) which is subjected to sand blasting and welding, the coating is sprayed within 1 hour after the sand blasting treatment of the base steel sheet is finished, after the spraying is finished, the steel sheet with the coating is cured for 7 days at room temperature, and baked for 3 days at 40 ℃ to obtain a sample, and pure epoxy resin (EP) is used as a control.

(1) The crystal structures of Gr, BN, BPA, gr/BPA and Gr/BPA@Si were characterized by X-ray diffraction (XRD, XPertPROMPD, cuK. Alpha. Ray diffraction, 5-80 ℃). The results are shown in FIG. 1. As can be seen from FIG. 1, after modification, characteristic diffraction peaks of Gr, BN and PANI can be detected simultaneously in an XRD spectrum of the hybrid material Gr/BPA@Si, which indicates that the hybrid material is successfully synthesized.

(2) The morphology of BN, BPA, gr/BPA and Gr/BPA@Si hybrid materials was observed using a JEOLJEM-2100 high resolution transmission electron microscope (HR-TEM) and the results are shown in FIG. 2. As can be seen from FIG. 2A, the h-BN presents a typical lamellar structure, and after polyaniline modification (FIG. 2B), an organic layer is uniformly loaded on the surface of the h-BN; after binding to graphene (fig. 2C), typical wrinkled sheets of graphene can be clearly observed; when modified with EPOSS (fig. 2D), the hybrid material surface becomes more rough. The Gr/BPA@Si hybrid material is successfully synthesized.

(3) The cross-sectional morphology of each coating was observed using a JSM-7500F scanning electron microscope, and the results are shown in fig. 3. As can be seen from FIG. 3, unmodified h-BN (FIG. 3B) appears to have significant agglomeration in the resin system with voids and cracks; as can be seen from fig. 3C and 3D, the modified BPA and Gr/BPA added to the coating reduced porosity and cracking; from fig. 3E it can be seen that Gr/bpa@si is well dispersed in the resin system, with no cross-sectional gaps and cracks found.

(4) And testing the temperature of the back surface of the steel plate by adopting a large plate method to detect the fireproof performance of the fireproof paint. The results are shown in FIG. 4. As can be seen from FIG. 4, the temperature of the back surface of the steel plate of the fireproof coating containing Gr/BPA@Si is the lowest, which shows that the fireproof performance is the best, and the synthesized hybrid material Gr/BPA@Si can effectively improve the strength and the oxidation resistance of the carbon layer of the fireproof coating, thereby improving the fireproof performance.

(5) The burning behavior of the different fire protection coatings was tested using a cone calorimeter (CCT, kunshan Mo Disi fire technologies limited) and the results are shown in fig. 5. From the average heat release rate plot (FIG. 5A) and the total heat release rate plot (FIG. 5B), it can be seen that the addition of Gr/BPA@Si hybrid material effectively reduces peak levels

The soaking release rate and the total heat release amount show that the Gr/BPA@Si hybrid filler can effectively inhibit and improve the flame retardant property of the fireproof coating; from the average smoke release amount graph (fig. 5C) and the total smoke release amount graph (fig. 5D), it can be seen that the addition of the Gr/bpa@si hybrid material effectively reduces the peak average smoke release rate and the total smoke release amount, indicating that the Gr/bpa@si hybrid material has better smoke suppression performance.

(6) The structure of the carbon layer after the cone calorimeter test is observed by using a JSM-7500F scanning electron microscope, and the result is shown in figure 6. As can be seen from FIG. 6, the carbon layers of EP, BN/EP, BPA/EP and Gr/BPA/EP all have cracks with different degrees, and when Gr/BPA@Si hybrid materials are added, the carbon layer structure of the Gr/BPA@Si/EP sample is uniform, a honeycomb carbon layer network is displayed, and the strength of the carbon layer is obviously enhanced. The modified two-dimensional Gr/BPA@Si nanometer hybrid material can effectively enhance the strength of the carbon layer, thereby improving the fireproof performance of the fireproof coating.

Therefore, the Gr/BPA@Si nano hybrid material and the fireproof coating prepared by the preparation method provided by the embodiment of the invention overcome the dangerous characteristics of low strength, poor oxidation resistance and uneven expansion of the existing water-based epoxy resin carbon layer, and the obtained nano fireproof coating carbon layer has the advantages of high strength, strong oxidation resistance, even expansion and greatly improved fireproof performance. The invention is mainly used for the fireproof protection of the steel structure, and can greatly delay the failure time of the steel structure when a fire disaster occurs, thereby striving for valuable time for personnel evacuation and fire rescue. The preparation process of the coating is simple and feasible, the cost is low, the environment is protected, the coating is suitable for industrial production, in the preparation process, gr/BPA@Si prepared by the embodiment of the invention is combined with water-based epoxy resin, and the prepared product has good high temperature resistance effect, strong adhesive force and wide application value.

The foregoing description of the embodiments has been provided for the purpose of illustrating the general principles of the invention, and is not meant to limit the scope of the invention, but to limit the invention to the particular embodiments, and any modifications, equivalents, improvements, etc. that fall within the spirit and principles of the invention are intended to be included within the scope of the invention.

Claims (5)

1. The preparation method of the Gr/BPA@Si nanometer hybrid material is characterized by comprising the following steps:

s1, dispersing BPA in a solvent to obtain a first dispersion liquid;

s2, dispersing Gr in the first dispersion liquid to obtain a second dispersion liquid;

s3, dripping the oligomeric silsesquioxane solution into the second dispersion liquid under the stirring state for reaction, and treating to obtain the Gr/BPA@Si nano hybrid material;

the preparation method of the BPA comprises the following steps:

t1, uniformly mixing hexagonal boron nitride, aniline monomer and water to obtain suspension;

t2, dropwise adding an ammonium persulfate hydrochloric acid aqueous solution into the suspension, and reacting to obtain BPA;

the mass ratio of the aniline monomer to the ammonium persulfate is 1:2.5-3.5; the mass ratio of the BPA to the hexagonal boron nitride is 1:0.05-0.15;

the mass ratio of BPA to the oligomeric silsesquioxane is 1:0.4-0.5;

the reaction temperature of the S2 is 75-85 ℃ and the reaction time is 45-55h; the solvent is absolute ethyl alcohol; the oligomeric silsesquioxane solution is an ethanol solution of oligomeric silsesquioxane;

in the hydrochloric acid aqueous solution of ammonium persulfate, the concentration of HCl in the hydrochloric acid aqueous solution is 0.05mol/L; the reaction temperature in the T2 is 0-5 ℃ and the reaction time is 6-10h.

2. A method of preparing a fire retardant coating comprising: uniformly mixing the base material with the Gr/BPA@Si nano hybrid material according to claim 1 to obtain the fireproof coating;

wherein the Gr/BPA@Si nano hybrid material accounts for 1.5% -3.5% of the total weight of the fireproof coating.

3. The preparation method of the fireproof coating according to claim 2, wherein the base material is uniformly mixed with the Gr/BPA@Si nano hybrid material according to claim 1 to obtain the fireproof coating; comprising the following steps:

uniformly mixing a base material, a defoaming agent and the Gr/BPA@Si nano hybrid material according to claim 1 to obtain the fireproof coating;

wherein the defoamer accounts for 0.5 to 1.5 percent of the total weight of the fireproof coating.

4. The method of preparing a fire retardant coating according to claim 2, wherein the method of preparing the base material comprises:

uniformly mixing epoxy resin, a curing agent and an expanding agent to obtain a uniformly mixed base material; wherein, the mass ratio of the epoxy resin to the curing agent is 2:1, a step of; the mass ratio of the epoxy resin to the expanding agent is 2-2.5:1 to 1.5; the expanding agent comprises the following components in percentage by mass of 5.5-6.5:2.5-3.5: melamine polyphosphate, dipentaerythritol and melamine in the range of 1 to 1.5.

5. Use of the Gr/bpa@si nanohybrid material according to claim 1 or the fire-retardant coating obtained by the preparation method of any one of claims 2 to 4 in the fire protection of steel structures.

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