CN118374061B - Modified basalt fiber cloth, reinforced cyano resin composite material and preparation method - Google Patents

Abstract

The present invention belongs to the field of fiber-reinforced polymer composite materials, and relates to a modified basalt fiber cloth, a reinforced cyano resin composite material and a preparation method. The modified basalt fiber reinforced cyano resin composite material of the present invention is prepared by a cyano resin containing benzoxazine and a modified basalt fiber cloth. The modified basalt fiber cloth of the present invention forms a physical interlock and a chemical bond with a matrix resin at the same time, and at the same time gives the modified basalt fiber cloth the ability to catalyze and cure thermosetting resins, thereby reducing the curing temperature of the resin and improving the mechanical and heat resistance properties of the composite material.

Description

Modified basalt fiber cloth, reinforced cyano resin composite material and preparation method

Technical Field

The invention belongs to the technical field of fiber-reinforced polymer composite materials, and relates to modified basalt fiber cloth, reinforced cyano resin composite materials and a preparation method thereof.

Background Art

Fiber-reinforced polymer composites have become an important role in the construction of modern society, ranging from civil automobiles, railway transportation and other industries to military manufacturing, aerospace and other high-tech fields. Basalt fiber (BF) is a new type of continuous inorganic fiber in recent years. It has the advantages of easy mining, abundant reserves, green and environmentally friendly preparation process, and outstanding performance characteristics such as high strength, high modulus, high heat resistance, flame retardancy, and fire resistance. Basalt fiber has similar environmentally friendly properties as natural fibers, but its mechanical strength is much higher than that of natural fibers. Compared with common glass fibers, its mechanical strength also has certain advantages; compared with carbon fibers, basalt fibers have excellent oxidation resistance and heat resistance, and lower cost. In view of the above characteristics, basalt fibers have great application potential in industries such as structure, construction, insulation, and automobiles. It is also an excellent fiber reinforcement phase choice for reinforced composite materials. However, its smooth surface morphology and chemical inertness make it difficult to bond with the polymer matrix on the surface, limiting its use as a reinforcing material. In order to enhance the bonding between basalt fiber and resin matrix and improve the interface strength between basalt fiber and resin matrix, basalt fiber is usually modified. Common methods include acid-base etching, electrochemical etching, plasma treatment, coupling agent reaction modification, etc. The basic principle of these methods is to use chemical or physical methods to cause certain damage to the fiber surface so that it can better mesh with the matrix material, thereby achieving the effect of interface modification.

At present, the modification of basalt fiber focuses on either surface chemical activation, the introduction of polymers with functional groups, or the growth of oxides or ceramic nanoparticles to increase roughness and physical entanglement. Few works use both to modify together, and basalt fiber is mostly modified in the form of chopped fibers for the reinforcement of thermoplastic polymers. Few basalt fiber cloth is modified to enhance the mechanical properties of thermosetting resins. The stirring and mixing operations involved in the general modification process of basalt fiber cloth are easy to damage the fiber cloth weaving structure; in addition, the gelation time of thermosetting resin (cyano resin) is as long as several days, and the curing temperature is high. Such polymerization conditions are obviously very unfavorable for production and application. Therefore, a basalt fiber cloth modification method is needed to overcome the problems of difficult modification of basalt fiber cloth, easy damage during the modification process, and difficulty in optimizing the interface strength, so as to improve the mechanical and heat resistance properties of basalt fiber reinforced matrix resin composites, and at the same time make the basalt fiber cloth have the ability to catalytically cure thermosetting resins and reduce the curing temperature of the resin.

Summary of the invention

In order to solve the above technical problems, the present invention provides a modified basalt fiber cloth, a reinforced cyano resin composite material and a preparation method, which overcomes the problems of difficult modification of basalt fiber cloth, easy damage during the modification process, and difficulty in optimizing the interface strength, and realizes the physical interlocking and chemical bond connection between the modified basalt fiber cloth and the matrix resin, effectively enhancing the interface strength, improving the mechanical and heat resistance of the basalt fiber reinforced cyano resin composite material, and at the same time giving the basalt fiber cloth the ability to catalyze the curing of thermosetting resins, thereby reducing the curing temperature of the resin.

The technical solution of the present invention to solve the above technical problems is as follows:

The present invention provides a modified basalt fiber cloth, which is prepared by the following preparation steps:

S101, treating the basalt fiber cloth in an oven for 2-3 hours;

S102, placing the basalt fiber cloth treated in step S101 in a dopamine solution, leaving it to stand at room temperature, soaking for 2-4 hours, taking out the basalt fiber cloth and drying it at 70° C. for 2 hours;

S103, taking the basalt fiber cloth dried in step S102 and subjecting it to irradiation treatment;

S104, respectively preparing a zinc acetate ethanol solution and a sodium hydroxide ethanol solution, mixing the two solutions, adding ethanol for ultrasonic dispersion, placing the irradiated basalt fibers therein, standing in a 60° C. water bath for reaction for 30 minutes, taking out and drying, and annealing in an air atmosphere at 200° C. for 10 minutes to obtain a basalt fiber cloth coated with a ZnO seed layer;

S105, adding zinc nitrate and hexamethylenetetramine into deionized water, stirring to dissolve, and then arranging the basalt fiber coated with the ZnO seed layer in step S104 therein, standing in a 90° C. water bath for reaction for 2 hours, taking out and drying to obtain a ZnO-modified basalt fiber cloth;

S106, preparing an acetone solution containing dopamine and epoxy resin E51, and placing the ZnO-modified basalt fiber cloth obtained in step S105 in the acetone solution for 2-3 hours to obtain a modified basalt fiber cloth.

Preferably, in step S101, the temperature of the oven is 300°C-350°C.

Preferably, in step S102, the concentration of the dopamine solution is 0.1-0.5 g/L, and the pH is 8.4.

Preferably, in step S103, the irradiation dose of the irradiation treatment is 100 KGy-800 KGy.

Preferably, in step S106, the total weight of the dopamine and the epoxy resin E51 accounts for 0.3%-2% of the weight of the basalt fiber cloth.

The present invention also provides a modified basalt fiber reinforced cyano resin composite material, wherein the composite material is prepared by a cyano resin containing benzoxazine and the modified basalt fiber cloth.

The present invention also provides a method for preparing the modified basalt fiber reinforced cyano resin composite material, comprising the following preparation steps:

S201, applying cyano resin glue on the modified basalt fiber cloth, and drying at 160° C. for half an hour to obtain a prepreg cloth;

S202, hot-pressing the prepreg obtained in step S201 at 240-300°C for 2 hours to obtain a modified basalt fiber reinforced cyano resin composite material.

Preferably, in step S201, the cyano resin glue is a phthalonitrile-based resin glue containing benzoxazine, and the preparation method of the cyano resin glue containing benzoxazine is: using N,N-dimethylformamide and toluene as solvents, bisphenol A, formaldehyde, and 3-aminophenyl-phthalonitrile as raw materials, magnetically stirring at 80° C. for 5 hours, reacting to obtain the phthalonitrile-based resin glue containing benzoxazine, and adjusting the solid content to 60%.

Preferably, in step S201, the weight ratio of the modified basalt fiber cloth to the cyano resin adhesive containing benzoxazine is 5.5:4.5.

Preferably, in step S202, the hot pressing method is: preheating at 240°C for 5 minutes without pressure, starting the hot press when the resin on the prepreg cloth becomes a fluid state, hot pressing for 1 hour at a temperature of 240°C and a pressure of 5 MPa, then keeping the pressure unchanged, raising the temperature to 280°C, and hot pressing for 0.5 hour.

The beneficial effects of the present invention are:

1. The present invention uses zinc oxide, dopamine and epoxy resin to perform multi-level structural modification on basalt fiber cloth. The zinc oxide nanowires grown on the modified basalt fiber cloth, dopamine and epoxy resin simultaneously form physical interlocking and chemical bond links between the modified basalt fiber cloth and the cyano resin, thereby more effectively enhancing the bonding between the basalt fiber and the matrix resin and improving the interface strength.

2. The present invention firstly adopts dopamine as an organic source. The irradiated dopamine produces more active sites, which is beneficial to the growth of zinc oxide. The chemical reaction between the directly coated dopamine and the basalt fiber is relatively weak, while the electron beam bombardment will make more organic functional groups grow on the fiber, so the zinc oxide grows more and is more solid. Compared with the direct irradiation of the basalt fiber cloth, more active sites can be produced, making the zinc oxide grow more firmly and not easy to fall off; the zinc oxide nanowires can roughen the fiber cloth, which is beneficial to physical entanglement and improves the bonding between the basalt fiber cloth and the cyano resin; finally, dopamine and epoxy resin are further irradiated. Co-coating is beneficial to further improve the interface strength and avoid separate coating stratification. Dopamine is relatively soft, and epoxy resin is relatively hard after copolymerization with the resin matrix. The obtained composite material is easy to separate when subjected to external force impact and can withstand less stress. Dopamine and epoxy resin are mixed together for coating, which can not only utilize the adhesion of dopamine, but also make it more tightly and firmly combined with the resin, with obvious reinforcement effect and greater interface force. The high adhesion of dopamine is used to enhance the interface effect, and the epoxy resin and the cyano resin containing benzoxazine form a chemical cross-linking structure to enhance the mechanical strength and heat resistance.

3. The irradiation used in the present invention is beneficial to better infiltration of the coated dopamine and the resin matrix on the fiber surface, avoiding agglomeration to a certain extent, and further improving the mechanical strength and heat resistance of the composite material;

4. The amino group and phenolic hydroxyl group in the dopamine finally coated on the modified basalt fiber cloth of the present invention can catalyze the polymerization reaction of thermosetting resin, reduce the curing temperature of the resin, increase the conversion rate of functional groups, and reduce the curing reaction conditions;

5. The preparation process of the modified basalt fiber cloth of the present invention is simple, and the modification process does not require mechanical stirring and other operations, which will not disrupt or damage the woven structure of the basalt fiber cloth. The modified basalt fiber cloth is suitable for modification of basalt fiber cloth and reinforcement of composite materials based on thermosetting resins.

6. The mechanical strength of the modified basalt fiber reinforced cyano resin composite material of the present invention is improved by 140MPa, and the glass transition temperature is increased from 380 ^° C to above 400 ^° C. In addition, during the preparation of the composite material, the dopamine of the modified basalt fiber cloth and the benzoxazine of the cyano resin cooperate to achieve a highly efficient self-catalytic effect, so that the composite material does not need to be prepared by adding a curing agent, effectively avoiding the problem that the introduction of a heterogeneous curing agent system will affect the uniformity of the system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a scanning electron microscope image of the basalt fiber of the present invention,

Among them, Figure 1 (a) is an electron microscope image of the untreated basalt fiber, Figure 1 (b) is an electron microscope image of the pretreated basalt fiber, Figure 1 (c) is an electron microscope image of the basalt fiber coated with dopamine in Example 3, Figure 1 (d) is an electron microscope image of the basalt fiber coated with dopamine in Example 1, Figure 1 (e) is an electron microscope image of the basalt fiber coated with dopamine in Example 2, Figure 1 (f) is an electron microscope image of the surface of the basalt fiber coated with dopamine in Example 3 after re-irradiation, and Figure 1 (g) is an electron microscope image of the surface of the basalt fiber coated with dopamine in Example 1 after re-irradiation. Electron microscope images of the basalt fiber surface, FIG1(h) is an electron microscope image of the basalt fiber surface after being coated with dopamine and then irradiated in Example 2, FIG1(i) is an electron microscope image of the basalt fiber obtained by directly irradiating without dopamine coating and growing ZnO, FIG1(j) is an electron microscope image of the basalt fiber surface after being coated with dopamine and then irradiated and then growing ZnO in Example 1, FIG1(k) is an electron microscope image of the basalt fiber surface after being coated with dopamine and then irradiated and then growing ZnO in Example 2, and FIG1(l) is an electron microscope image of the basalt fiber after being finally coated with dopamine and epoxy resin in Example 1;

FIG2 is the XPS and XRD spectra of the basalt fiber cloth of Example 1 and Comparative Example 1 of the present invention,

Among them, Figure 2 (a) is the XPS full spectrum of the modified basalt fiber cloth of Example 1, Figure 2 (b) is the XPS oxygen element spectrum of the modified basalt fiber cloth of Example 1, Figure 2 (c) is the XPS zinc element spectrum of the modified basalt fiber cloth of Example 1, and Figure 2 (d) is the XRD spectrum of the modified basalt fiber cloth of Example 1 and the unmodified basalt fiber cloth of Comparative Example 1;

FIG. 3 is a photograph of the composite material of Example 1 of the present invention.

DETAILED DESCRIPTION

The principles and features of the present invention are described below (in conjunction with the accompanying drawings). The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

The sources of some raw materials of the present invention are as follows:

Basalt fiber cloth was purchased from Sichuan Glass Fiber Group Co., Ltd.; dopamine was purchased from Aladdin Reagent Co., Ltd.; epoxy E51 was purchased from Shandong Pinshang New Materials Co., Ltd.

The present invention provides a modified basalt fiber cloth, which is prepared by the following preparation steps:

S101, treating the basalt fiber cloth in an oven for 2-3 hours;

S102, placing the basalt fiber cloth treated in step S101 in a dopamine solution, leaving it to stand at room temperature, soaking for 2-4 hours, taking out the basalt fiber cloth and drying it at 70° C. for 2 hours;

S103, taking the basalt fiber cloth dried in step S102 and subjecting it to irradiation treatment;

S104, respectively preparing a zinc acetate ethanol solution and a sodium hydroxide ethanol solution, mixing the two solutions, adding ethanol for ultrasonic dispersion, placing the irradiated basalt fibers therein, standing in a 60° C. water bath for reaction for 30 minutes, taking out and drying, and annealing in an air atmosphere at 200° C. for 10 minutes to obtain a basalt fiber cloth coated with a ZnO seed layer;

S105, adding zinc nitrate and hexamethylenetetramine into deionized water, stirring to dissolve, and then arranging the basalt fiber coated with the ZnO seed layer in step S104 therein, standing in a 90° C. water bath for reaction for 2 hours, taking out and drying to obtain a ZnO-modified basalt fiber cloth;

S106, preparing an acetone solution containing dopamine and epoxy resin E51, and placing the ZnO-modified basalt fiber cloth obtained in step S105 in the acetone solution for 2-3 hours to obtain a modified basalt fiber cloth.

In step S101, the basalt fiber cloth is treated in an oven for 2-3 hours to remove the impregnation agent and facilitate the modification treatment;

In steps S102 and S103, dopamine is first used as an organic source to provide active sites, and then the dopamine on the basalt fiber cloth is irradiated. The irradiated dopamine produces more active sites, which is beneficial to the growth of zinc oxide. Compared with direct irradiation of basalt fiber cloth, more active sites can be produced, making the zinc oxide grow more firmly and not easy to fall off; at the same time, irradiation is more conducive to better infiltration of the coated dopamine and the resin matrix on the fiber surface, avoiding a certain degree of agglomeration, and further improving the mechanical strength and heat resistance of the composite material;

In steps S104 and S105, the growth of zinc oxide is divided into two steps and the annealing treatment is more conducive to the uniform and denser growth of zinc oxide. One-step growth is more likely to fall off. Annealing after the long seed layer makes the zinc oxide more tightly bound. In step S104, the system is placed in a 60°C water bath for static reaction. 60°C makes the reaction more complete and faster, and the ZnO seeds grow more firmly.

In step S106, dopamine and epoxy are finally used for co-coating. Co-coating is more conducive to improving the interface strength, while single coating is prone to stratification. When coated alone, dopamine is relatively soft, and epoxy resin is relatively hard after copolymerization with the resin matrix. The obtained composite material is easy to separate when impacted by external force and can withstand less stress. Dopamine and epoxy resin are mixed together for coating, which can not only utilize the adhesion of dopamine, but also make it more tightly and firmly combined with the resin, with obvious reinforcement effect and greater interface force.

As an optional implementation, in step S101, the temperature of the oven is 300°C-350°C.

The oven temperature is controlled at 300℃-350℃. If the temperature is lower than 300℃, the wetting agent cannot be completely removed, and if the temperature is higher than 350℃, resources will be wasted.

As an optional implementation, in step S102, the concentration of the dopamine solution is 0.1-0.5 g/L, and the pH is 8.4.

The concentration of the dopamine solution is controlled at 0.1-0.5g/L, so that sufficient active sites are formed, the zinc oxide grows fully and firmly, and is not easy to fall off; when the concentration of the dopamine solution is higher than 0.5g/L, there is too much dopamine, and the zinc oxide does not grow firmly enough and is easy to fall off; when the concentration of the dopamine solution is lower than 0.5g/L, there is too little dopamine, and few active sites are formed, and the zinc oxide does not grow enough; the pH is controlled at 8.4 to make the reaction temperature, which is convenient for controlling the reaction.

As an optional implementation, in step S103, the irradiation dose of the irradiation treatment is 100 KGy-800 KGy.

When the irradiation dose is lower than 100KGy, it is not conducive to the growth of zinc oxide. When the irradiation dose is higher than 800KGy, all organic matter will be decomposed, which is not conducive to bonding.

As an optional implementation, in step S106, the total weight of the dopamine and the epoxy resin E51 accounts for 0.3%-2% of the weight of the basalt fiber cloth.

When the total weight of dopamine and epoxy resin is less than 0.3% of the weight of basalt fiber cloth, the catalytic effect is not obvious and the interface strength is reduced; when the total weight of dopamine and epoxy resin is higher than 2% of the weight of basalt fiber cloth, the heat resistance of the composite material will be reduced.

The present invention also provides a modified basalt fiber reinforced cyano resin composite material, wherein the composite material is prepared by a cyano resin containing benzoxazine and the modified basalt fiber cloth.

The present invention also provides a method for preparing the modified basalt fiber reinforced cyano resin composite material, comprising the following preparation steps:

S201, applying cyano resin glue on the modified basalt fiber cloth, and drying at 160° C. for half an hour to obtain a prepreg cloth;

S202, hot-pressing the prepreg obtained in step S201 at 240-300°C for 2 hours to obtain a modified basalt fiber reinforced cyano resin composite material.

As an optional implementation, in step S201, the cyano resin glue is a phthalonitrile-based resin glue containing benzoxazine, and the preparation method of the cyano resin glue containing benzoxazine is: using N,N-dimethylformamide and toluene as solvents, bisphenol A, formaldehyde, and 3-aminophenyl-phthalonitrile as raw materials, magnetically stirring at 80°C for 5 hours, reacting to obtain the phthalonitrile-based resin glue containing benzoxazine, and adjusting the solid content to 60%.

The benzoxazine structure can effectively cooperate with the excellent properties of phthalonitrile, ensuring excellent thermal stability while taking into account flexible molecular structure design. Under thermal reaction conditions, ring-opening polymerization will occur to form a Mannich bridge structure, generating a large number of phenolic hydroxyl and amine structures. These structures will have a positive promoting effect on the polymerization reaction, thereby achieving a self-catalytic effect and promoting the curing of phthalonitrile.

The solid content of the phthalonitrile-based resin adhesive containing benzoxazine is controlled at 60%, so that the resin on the fiber cloth is fully impregnated and the performance of the composite material is enhanced.

As an optional implementation, in step S201, the weight ratio of the modified basalt fiber cloth to the cyano resin adhesive containing benzoxazine is 5.5:4.5.

As an optional embodiment, in step S202, the hot pressing method is: preheating at 240°C for 5 minutes without pressure, starting the hot press when the resin on the prepreg cloth becomes a fluid state, hot pressing for 1 hour at a temperature of 240°C and a pressure of 5 MPa, then keeping the pressure unchanged, raising the temperature to 280°C, and hot pressing for 0.5 hour.

The temperature can be controlled at 240°C to gel, and then the temperature is raised to 280°C for curing to increase the functional group conversion rate, improve the degree of curing and heat resistance.

The present invention is described in detail below in conjunction with embodiments and experimental data.

Example 1

A method for preparing a modified basalt fiber cloth comprises the following preparation steps:

S101, cut the basalt warp and weft cloth into 10 square samples of 10 cm×10 cm, then put it into an acetone-anhydrous ethanol mixed solution (the mass ratio of acetone to anhydrous ethanol is 3:7), soak it for 24 hours, take out the fiber cloth and put it into a 300°C high-temperature oven, heat treat it in air atmosphere for 3 hours, take it out, cool it and set it aside;

S102, add 0.2g dopamine powder to 500ml deionized water, stir and shake at room temperature to fully dissolve it until the solution becomes transparent, slowly add Tris buffer to the solution until the pH of the solution is 8.4; put the basalt fiber cloth treated by S101 into the dopamine hydrochloride solution of the previous step, soak it at room temperature for 4h, take it out and rinse off the unabsorbed residue on the surface with clean water, and put it in an oven at 70℃ to dry for 2h;

S103, placing the fiber cloth with dopamine loaded on the surface obtained in step S102 into a GJ-2 electron accelerator, and irradiating it with an electron beam in an air atmosphere at an irradiation intensity of 400 KGy;

S104, respectively preparing a zinc acetate ethanol solution with a concentration of 0.0125 mol/L and a sodium hydroxide ethanol solution with a concentration of 0.02 mol/L, taking 16 ml of each solution, mixing, adding 168 ml of ethanol, and performing ultrasonic dispersion for 2 minutes; placing the irradiated basalt fiber cloth into the prepared solution, standing in a 60°C water bath for reaction for 30 minutes, then taking out the basalt fiber cloth, drying it, and annealing it in an air atmosphere at 200°C for 10 minutes to obtain a basalt fiber cloth coated with a ZnO seed layer;

S105, adding 3.7g zinc nitrate and 1.75g hexamethylenetetramine into 500ml deionized water, stirring for 10min to fully dissolve them, then arranging the basalt fiber coated with the ZnO seed layer therein, standing in a 90°C water bath for reaction for 2h, taking out and drying to obtain ZnO nanowires on the surface of the basalt fiber cloth;

S106, taking 500 ml of acetone solution, adding 0.2 g of dopamine and 0.25 g of epoxy resin E51, stirring thoroughly to dissolve the epoxy resin in the acetone solution, and placing the modified basalt fiber cloth obtained in the previous step in the acetone solution for 2-3 hours to obtain a multi-stage modified basalt fiber cloth.

A method for preparing a modified basalt fiber reinforced cyano resin composite material comprises the following preparation steps:

S201, using N,N-dimethylformamide and toluene as solvents, bisphenol A, formaldehyde, and 3-aminophenyl-phthalonitrile as raw materials, and magnetically stirring at 80°C for 5 hours to obtain a phthalonitrile-based resin containing benzoxazine, and adjusting the solid content to 60% for standby use; weighing the weights of 10 fiber cloths, calculating and weighing the phthalonitrile resin containing benzoxazine according to the ratio of fiber cloth: resin glue = 5.5:4.5, and evenly coating the resin glue on each fiber cloth, and then drying it in an oven at 160°C for half an hour to remove the solvent, to obtain a prepreg cloth;

S202. Completely fit and overlap the prepreg fiber cloth, put it into a hot press, and preheat it at 240°C without pressure for 5 minutes. When the resin on the prepreg cloth becomes a fluid state, start the hot press, and allow the resin gel to be hot-pressed at a temperature of 240°C and a pressure of 5 MPa for 1 hour. Then, the pressure remains unchanged, the temperature is raised to 280°C, and hot-pressed for 0.5 hour. After the hot-pressing is completed, a 10 cm×10 cm composite laminate is obtained. After the sample is cooled, it is taken out to obtain a modified basalt fiber reinforced cyano resin composite material.

Example 2

A method for preparing a modified basalt fiber cloth comprises the following preparation steps:

S101, cut the basalt warp and weft cloth into 10 square samples of 10 cm × 10 cm, then put them into an acetone-anhydrous ethanol mixed solution (the mass ratio of acetone to anhydrous ethanol is 3:7), soak them for 24 hours, take out the fiber cloth and put it into a 300°C high-temperature oven, heat treat it in air atmosphere for 3 hours, take it out, cool it and set it aside;

S102, add 0.25g dopamine powder to 500ml deionized water, stir and shake at room temperature to fully dissolve it until the solution becomes transparent, slowly add Tris buffer to the solution until the pH of the solution is 8.4; put the basalt fiber cloth treated by S101 into the dopamine hydrochloride solution of the previous step, soak it at room temperature for 4h, take it out and rinse off the unabsorbed residue on the surface with clean water, and put it in an oven at 70℃ to dry for 1h;

S103, placing the fiber cloth with dopamine loaded on the surface obtained in step S102 into a GJ-2 electron accelerator, and irradiating it with an electron beam in an air atmosphere at an irradiation intensity of 200 KGy;

S104, prepare 0.025 mol/L zinc acetate ethanol solution and 0.04 mol/L sodium hydroxide ethanol solution respectively, take 16 ml of each solution, mix them, add 168 ml of ethanol and perform ultrasonic dispersion for 2 minutes. Put the irradiated basalt fiber cloth into the prepared solution, let it stand in a 60°C water bath for 30 minutes, then take out the basalt fiber cloth, dry it, and anneal it in an air atmosphere at 200°C for 10 minutes to obtain a basalt fiber cloth coated with a ZnO seed layer;

S105, adding 5g zinc nitrate and 2.4g hexamethylenetetramine into 500ml deionized water, stirring for 10min to fully dissolve them, then arranging the basalt fiber coated with the ZnO seed layer therein, standing in a 90°C water bath for reaction for 2h, taking out and drying to obtain ZnO nanowires on the surface of the basalt fiber cloth;

S106, taking 500 ml of acetone solution, adding 0.2 g of dopamine and 0.25 g of epoxy resin E51, stirring thoroughly to dissolve the epoxy resin in the acetone solution, and placing the modified basalt fiber cloth obtained in the previous step in the acetone solution for 2-3 hours to obtain a multi-stage modified basalt fiber cloth.

A method for preparing a modified basalt fiber reinforced cyano resin composite material comprises the following preparation steps:

S201. Use N,N-dimethylformamide and toluene as solvents, bisphenol A, formaldehyde, and 3-aminophenyl-phthalonitrile as raw materials, stir magnetically at 80°C for 5 hours, and react to obtain a phthalonitrile-based resin containing benzoxazine. Adjust the solid content to 60% for later use. Weigh the weight of 10 fiber cloths, calculate and weigh the phthalonitrile resin containing benzoxazine according to the ratio of fiber cloth: resin glue = 5.5:4.5, evenly apply the resin glue on each fiber cloth, and then put it in an oven and dry it at 160°C for half an hour to remove the solvent to obtain a prepreg cloth;

S202, completely overlap the prepreg fiber cloth, put it into the hot press, preheat it at 240℃ without pressure for 5 minutes, start the hot press when the resin on the prepreg cloth becomes fluid, and hot press for 1 hour at 240℃ and 5MPa, then keep the pressure unchanged, raise the temperature to 280℃, and hot press for 0.5 hour. After the hot press is completed, a 10cm×10cm composite laminate is obtained, and the sample is taken out after cooling to obtain a modified basalt fiber reinforced cyano resin composite material.

Example 3

A method for preparing a modified basalt fiber cloth comprises the following preparation steps:

S101, cut the basalt warp and weft cloth into 10 square samples of 10 cm×10 cm, then put it into an acetone-anhydrous ethanol mixed solution (the mass ratio of acetone to anhydrous ethanol is 3:7), soak it for 24 hours, take out the fiber cloth and put it into a 300°C high-temperature oven, heat treat it in air atmosphere for 3 hours, take it out, cool it and set it aside;

S102, add 0.1g dopamine powder to 500ml deionized water, stir and shake at room temperature to fully dissolve it until the solution becomes transparent, slowly add Tris buffer to the solution until the pH of the solution is 8.4; put the treated fiber cloth into the dopamine hydrochloride solution of the previous step, soak it at room temperature for 4h, take it out and rinse off the residue not adsorbed on the surface with clean water, and put it in an oven at 70℃ to dry for 1h;

S103, placing the fiber cloth with dopamine loaded on the surface into a GJ-2 electron accelerator, and irradiating it with an electron beam in an air atmosphere at an irradiation intensity of 800 KGy;

S104, respectively preparing a zinc acetate ethanol solution with a concentration of 0.0125 mol/L and a sodium hydroxide ethanol solution with a concentration of 0.02 mol/L, taking 16 ml of each solution, mixing, adding 168 ml of ethanol, and performing ultrasonic dispersion for 2 minutes; placing the irradiated basalt fiber cloth into the prepared solution, standing in a 60°C water bath for reaction for 30 minutes, then taking out the basalt fiber cloth, drying it, and annealing it in an air atmosphere at 200°C for 10 minutes to obtain a basalt fiber cloth coated with a ZnO seed layer;

S105, adding 3.7g zinc nitrate and 1.75g hexamethylenetetramine into 500ml deionized water, stirring for 10min to fully dissolve them, then arranging the basalt fiber coated with the ZnO seed layer therein, standing in a 90°C water bath for reaction for 2h, taking out and drying to obtain ZnO nanowires on the surface of the basalt fiber cloth;

S106, taking 500 ml of acetone solution, adding 0.1 g of dopamine and 0.5 g of epoxy resin E51, stirring thoroughly to dissolve the epoxy resin in the acetone solution, and placing the modified basalt fiber cloth obtained in the previous step in the acetone solution for 2-3 hours to obtain a multi-stage modified basalt fiber cloth.

A method for preparing a modified basalt fiber reinforced cyano resin composite material comprises the following preparation steps:

S201, using N,N-dimethylformamide and toluene as solvents, bisphenol A, formaldehyde, and 3-aminophenyl-phthalonitrile as raw materials, and magnetically stirring at 80°C for 5 hours to obtain a phthalonitrile-based resin containing benzoxazine, and adjusting the solid content to 60% for standby use; weighing the weights of 10 fiber cloths, and calculating and weighing the phthalonitrile resin containing benzoxazine according to the ratio of fiber cloth: resin glue = 5.5:4.5; evenly coating the resin glue on each fiber cloth, and then drying it in an oven at 160°C for half an hour to remove the solvent, to obtain a prepreg cloth;

S202, completely overlap the prepreg fiber cloth, put it into the hot press, preheat it at 240℃ without pressure for 5 minutes, start the hot press when the resin on the prepreg cloth becomes fluid, and hot press for 1 hour at 240℃ and 5MPa, then keep the pressure unchanged, raise the temperature to 280℃, and hot press for 0.5 hour. After the hot press is completed, a 10cm×10cm composite laminate is obtained, and the sample is taken out after cooling to obtain a modified basalt fiber reinforced cyano resin composite material.

Comparative Example 1

The basalt fiber cloth was cut into 10 square pieces of 10 cm × 10 cm, and then placed in an acetone-anhydrous ethanol mixed solution (the mass ratio of acetone to anhydrous ethanol was 3:7). After soaking for 24 hours, the fiber cloth was taken out and placed in a 300°C high-temperature oven. After heat treatment for 3 hours in air atmosphere, it was taken out and cooled for use.

N,N-dimethylformamide and toluene are used as solvents, bisphenol A, formaldehyde, and 3-aminophenyl-phthalonitrile are used as raw materials, and magnetic stirring is performed at 80°C for 5h to obtain a phthalonitrile-based resin containing benzoxazine. The solid content is adjusted to 60% for standby use. The weight of 10 fiber cloths is obtained, and the phthalonitrile resin containing benzoxazine is calculated and weighed according to the ratio of fiber cloth: resin glue = 5.5:4.5. The resin glue is evenly coated on each fiber cloth, and then placed in an oven and dried at 160°C for half an hour to remove the solvent to obtain a prepreg cloth. The prepreg fiber cloth is completely laminated and overlapped, placed in a hot press, and preheated at 240°C without pressure for 5 minutes. When the resin on the prepreg cloth becomes a flowing state, the hot press is started, and hot pressing is performed at a temperature of 240°C and a pressure of 5MPa for 1h. Then the pressure remains unchanged, the temperature is raised to 280°C, and hot pressing is performed for 0.5h. After the hot pressing, a composite laminate of 10 cm×10 cm was obtained. After the sample was cooled, it was taken out to obtain a basalt fiber reinforced cyano resin composite material.

Comparative Example 2

A method for preparing a modified basalt fiber cloth comprises the following preparation steps:

S101, cut the basalt warp and weft cloth into 10 square samples of 10 cm×10 cm, then put it into an acetone-anhydrous ethanol mixed solution (the mass ratio of acetone to anhydrous ethanol is 3:7), soak it for 24 hours, take out the fiber cloth and put it into a 300°C high-temperature oven, heat treat it in air atmosphere for 3 hours, take it out, cool it and set it aside;

S102, add 0.2g dopamine powder to 500ml deionized water, stir and shake at room temperature to fully dissolve it until the solution becomes transparent, slowly add Tris buffer to the solution until the pH of the solution is 8.4; put the basalt fiber cloth treated by S101 into the dopamine hydrochloride solution of the previous step, soak it at room temperature for 4h, take it out and rinse off the unabsorbed residue on the surface with clean water, and put it in an oven at 70℃ to dry for 2h;

S103, respectively preparing a zinc acetate ethanol solution with a concentration of 0.0125 mol/L and a sodium hydroxide ethanol solution with a concentration of 0.02 mol/L, taking 16 ml of each solution, mixing, adding 168 ml of ethanol, and performing ultrasonic dispersion for 2 minutes; placing the irradiated basalt fiber cloth into the prepared solution, standing in a 60°C water bath for reaction for 30 minutes, then taking out the basalt fiber cloth, drying it, and annealing it in an air atmosphere at 200°C for 10 minutes to obtain a basalt fiber cloth coated with a ZnO seed layer;

S104, adding 3.7g zinc nitrate and 1.75g hexamethylenetetramine into 500ml deionized water, stirring for 10min to fully dissolve them, then arranging the basalt fiber coated with the ZnO seed layer therein, standing in a 90°C water bath for reaction for 2h, taking out and drying to obtain ZnO nanowires on the surface of the basalt fiber cloth;

S105, taking 500 ml of acetone solution, adding 0.2 g of dopamine and 0.25 g of epoxy resin E51, stirring thoroughly to dissolve the epoxy resin in the acetone solution, and placing the modified basalt fiber cloth obtained in the previous step in the acetone solution for 2-3 hours to obtain a multi-stage modified basalt fiber cloth.

A method for preparing a modified basalt fiber reinforced cyano resin composite material is the same as the method for preparing the composite material in Example 1.

Comparative Example 3

A method for preparing a modified basalt fiber cloth is the same as the method for preparing the modified basalt fiber cloth in Example 1.

A method for preparing a modified basalt fiber reinforced cyano resin composite material comprises the following preparation steps:

S201, using N,N-dimethylformamide and toluene as solvents, bisphenol A, formaldehyde, and 3-aminophenyl-phthalonitrile as raw materials, and magnetically stirring at 80°C for 5 hours to obtain a phthalonitrile-based resin containing benzoxazine, and adjusting the solid content to 60% for standby use; weighing the weights of 10 fiber cloths, calculating and weighing the phthalonitrile resin containing benzoxazine according to the ratio of fiber cloth: resin glue = 5.5:4.5, and evenly coating the resin glue on each fiber cloth, and then drying it in an oven at 160°C for half an hour to remove the solvent, to obtain a prepreg cloth;

S202. Completely fit and overlap the prepreg fiber cloth, put it into a hot press, and preheat it at 200°C without pressure for 5 minutes. When the resin on the prepreg cloth becomes a fluid state, start the hot press, and allow the resin gel to be hot-pressed at a temperature of 200°C and a pressure of 5 MPa for 1 hour. Then, the pressure remains unchanged, the temperature is raised to 240°C, and hot-pressed for 0.5 hour. After the hot-pressing is completed, a 10 cm×10 cm composite laminate is obtained. After the sample is cooled, it is taken out to obtain a modified basalt fiber reinforced cyano resin composite material.

Comparative Example 4

A method for preparing a modified basalt fiber cloth is the same as the method for preparing the modified basalt fiber cloth in Example 1.

A method for preparing a modified basalt fiber reinforced cyano resin composite material comprises the following preparation steps:

S201, using N,N-dimethylformamide and toluene as solvents, bisphenol A, formaldehyde, and 3-aminophenyl-phthalonitrile as raw materials, and magnetically stirring at 80°C for 5 hours to obtain a phthalonitrile-based resin containing benzoxazine, and adjusting the solid content to 40% for standby use; weighing the weights of 10 fiber cloths, calculating and weighing the phthalonitrile resin containing benzoxazine according to the ratio of fiber cloth: resin glue = 5.5:4.5, and evenly coating the resin glue on each fiber cloth, and then drying it in an oven at 160°C for half an hour to remove the solvent, to obtain a prepreg cloth;

S202. Completely fit and overlap the prepreg fiber cloth, put it into a hot press, and preheat it at 240°C without pressure for 5 minutes. When the resin on the prepreg cloth becomes a fluid state, start the hot press, and allow the resin gel to be hot-pressed at a temperature of 240°C and a pressure of 5 MPa for 1 hour. Then, the pressure remains unchanged, the temperature is raised to 280°C, and hot-pressed for 0.5 hour. After the hot-pressing is completed, a 10 cm×10 cm composite laminate is obtained. After the sample is cooled, it is taken out to obtain a modified basalt fiber reinforced cyano resin composite material.

Comparative Example 5

A method for preparing a modified basalt fiber cloth is different from the method for preparing the modified basalt fiber cloth in Example 2 except for S106, and other operations are the same; S106 of this comparative example is to take 500 ml of acetone solution, add 0.2 g of dopamine, stir thoroughly to dissolve the dopamine in the acetone solution, and place the modified basalt fiber cloth obtained in the previous step in the acetone solution for 2-3 hours to obtain a multi-stage modified basalt fiber cloth.

A method for preparing a modified basalt fiber reinforced cyano resin composite material is the same as the method for preparing the modified basalt fiber cloth in Example 2.

The following examples illustrate the beneficial effects of the present invention. The experimental methods in the following examples without specifying specific conditions are usually measured according to national standards. If there are no corresponding national standards, the methods are carried out according to the general international standards, conventional conditions, or conditions recommended by the manufacturer.

Test example

1. Characterization and analysis of modified basalt fiber cloth

1. SEM

The basalt fiber cloths at various stages of Example 1 and the basalt fiber cloths of Examples 2-3 were characterized using a scanning electron microscope, and the basalt fiber without dopamine coating and directly irradiated and grown with ZnO was characterized. The characterization results are shown in FIG1 .

Figure 1 is a scanning electron microscope image of basalt fiber cloth before and after modification. Figure 1 (a) is an electron microscope image of untreated basalt fiber, with many adhesives on the surface. Figure 1 (b) is an electron microscope image of pretreated basalt fiber. It can be seen that the surface of the pretreated basalt fiber is very smooth. Figures 1 (c)-(e) are electron microscope images of basalt fibers coated with dopamine in Example 3, Example 1, and Example 2, respectively. (f)-(h) are the fiber surfaces of Example 3, Example 1, and Example 2 after being coated with dopamine and then irradiated. Electron microscope images, (i) is an electron microscope image of a fiber sample obtained by directly irradiating and growing ZnO without dopamine coating, (j)-(k) are electron microscope images of the surface of basalt fibers coated with dopamine and then irradiated and then grown with ZnO in Experimental Examples 1 and 2. EDS analysis shows that the dense rod-like structure on the surface is ZnO; (l) is an electron microscope image of the basalt fiber after being coated with dopamine and epoxy resin in Example 1. As can be seen from Figure 1, the ZnO particles obtained by directly growing ZnO without dopamine coating are small, and the morphology is uneven and unstable.

2. XPS, XRD

XPS and XRD analyses were performed on the modified basalt fiber cloth of Example 1 and the unmodified basalt fiber cloth of Comparative Example 1, and the test results are shown in FIG2 .

FIG2 is the XPS and XRD results of the modified basalt fiber cloth of Example 1. FIG2 (a) is the full XPS spectrum, FIG2 (b) is the oxygen element spectrum of XPS, and FIG2 (c) is the zinc element spectrum of XPS. As can be seen from FIG2, the center of the O1s high-resolution spectrum peak is at 529.8 eV, corresponding to the oxygen (O-Zn bond) in zinc oxide, and the other peaks belong to the Si-O bond and other metal oxides, corresponding to the metal oxides in the basalt fiber. In FIG2 (a) and (c), Zn2p3/2 and Zn2p1/2 in the Zn-O bond can be detected at 1021.3 eV and 1044.4 eV, respectively. FIG2 (d) is the XRD spectrum of the unmodified basalt fiber of Comparative Example 1 and the modified basalt fiber of Example 1. In the XRD spectrum of the modified fiber, 2θ = Six sharp diffraction peaks can be observed at 31.6o, 34.6o, 36.2o, 47.6o, 56.5o and 62.9o, which correspond to the (100), (002), (101), (102), (110) and (103) crystal planes of ZnO, while the unmodified fibers do not have these diffraction peaks.

2. Bending mechanical test of composite materials

The composite materials of Examples 1-3 and Comparative Examples 1-5 were subjected to bending mechanical tests: a three-point bending method was adopted, the crosshead displacement test speed was 5 mm/min, the support span to thickness ratio was 15:1, and the results were taken as the average of three samples. The test results are shown in Table 1 below:

Table 1 Bending mechanical test results

As can be seen from Table 1, the bending strength and bending modulus of Examples 1-3 are greatly improved compared with Comparative Examples 1-4, indicating that the multi-level surface modification of basalt fibers effectively improves the interface properties of the composite material, thereby improving the mechanical properties of the material; in the examples, Example 1 is the best, Example 2 is the worst, and Example 3 is between the two, indicating that the optimal dopamine modification concentration for the fiber is around 0.2g/500ml. Too high a dopamine concentration may affect the uniformity of the fiber surface and the growth of ZnO, making it impossible for the interface to reach the optimal state, thereby causing a certain degree of decline in the mechanical properties; and for the samples of the other comparative example groups, it was found that the bending strength and bending modulus of Comparative Example 3 were The lowest, indicating that the curing temperature during hot pressing is too low, resulting in incomplete resin curing and the worst mechanical properties; the non-irradiated comparative example 2 has a certain improvement over the completely unmodified comparative example 1 group, which is lower than the experimental group, indicating that the effect of irradiation on fiber surface modification is very critical, and comparative example 4 shows that too little resin matrix will lead to insufficient resin impregnation on the fiber and poor performance. Comparative example 5 only lacks epoxy E51 compared to example 2, but the performance is greatly reduced, which shows that the low-intensity irradiation level will lead to insufficient roughness of fiber surface modification, resulting in the inability to evenly coat excessive dopamine and causing agglomeration, thereby resulting in a decrease in mechanical properties. Not only that, it also shows that the presence of epoxy can effectively improve the brittleness of the resin and improve the mechanical properties.

3. Performance Analysis

1. Thermal stability analysis of composite materials

The thermal stability of the composite materials of Examples 1-3 and Comparative Examples 1-5 was studied by thermogravimetric analysis (TGA): the test was conducted by heating from 50 to 800°C at a heating rate of 20°C/min and a flow rate of 40 mL/min in a nitrogen atmosphere. The test results are shown in Table 2 below:

Table 2 Thermal stability test results

As shown in Table 2, the 5% mass loss temperature of the embodiments is better than that of the comparative example, among which embodiment 1> embodiment 3> embodiment 2, but the 10% mass loss temperature of embodiments 2 and 3 is almost the same as that of the comparative example. The dopamine concentration coated on the fiber surface in embodiment 2 is higher, and the thicker coating layer will lead to insufficient firmness of the interface bonding. On the contrary, embodiment 3 has less dopamine on the surface and the effect of improving the interface bonding is not enough, so it is similar to the effect of the unmodified comparative example. Only the value of embodiment 1 is slightly higher than the other three. This shows that while embodiment 1 ensures the best interface performance, the epoxy resin and dopamine coating layer effectively catalyzes The highly cross-linked network slightly delayed the damage of the resin structure to the high temperature. The too low 5% mass loss temperature in Example 3 was due to the insufficient temperature in the hot pressing program, resulting in insufficient curing of the resin compared with other samples under the same hot pressing time. This shows that the cross-linking degree of the resin will affect the mass loss temperature. Comparative Examples 1 and 4 show that the interfacial properties have a certain influence on the thermal weight loss temperature, but the curing degree of the resin matrix is the most critical influencing factor. The data of the seven groups of samples at 800°C carbon residue are similar, because only basalt fiber exists at this temperature, so the carbon residue is similar. In summary, the appropriate dopamine coating concentration, irradiation intensity, and epoxy dopamine mixed solution concentration of the embodiment provide excellent fiber-resin interface bonding performance, and the complete curing of the resin matrix and its complete infiltration on the fiber surface make the embodiment more thermally stable than the comparative example. Comparative Example 5 effectively illustrates that low modified strength of the fiber surface but excessive coating will lead to too many interface bonding defects, and the lack of epoxy resin also makes the curing degree of the matrix resin insufficient to a certain extent. These comprehensive factors greatly reduce the heat resistance of the composite material.

2. Dynamic mechanics and thermomechanical analysis of composite materials

(1) Dynamic Mechanical Analysis: The composite materials of Examples 1-3 and Comparative Example 1 were tested by dynamic mechanical analysis (DMA) in an air atmosphere at a heating rate of 5°C/min from 30°C to 400°C. The glass transition temperature Tg was obtained from the loss tangent curve. The results are shown in Table 3 below:

Table 3 Dynamic mechanical analysis test results

As can be seen from Table 3, the glass transition temperature Tg obtained in the dynamic mechanical analysis (DMA) well illustrates that the appropriate amount of epoxy and dopamine layers have a certain catalytic effect on the resin. Example 1 and Example 3 have glass transition temperatures Tg that are 20°C and 12°C higher than those of Comparative Example 1, and Example 1 is 32°C and 27°C higher than those of Comparative Examples 2 and 4, respectively, indicating that the degree of interfacial bonding also has a certain influence on Tg. The Tg of Example 2 and the Comparative Example are similar, indicating that the curing degrees of the two resins are similar; the glass transition temperature Tg of Comparative Example 3 is the lowest, indicating that its crosslinking degree is the lowest, which confirms the above analysis.

(2) Thermomechanical analysis: The composite material (strip size is 10×10×2 mm, width, length, thickness) was tested using the thermomechanical analysis method TMA. The test results are shown in Table 4 below:

Table 4 Thermal stability test results

As shown in Table 4, TMA obtained a slightly different glass transition temperature Tg from DMA. This may be because in the process of cutting the sample into 10×10×2 mm samples, the vibration of the cutting machine will affect the interface bonding of the sample, so the interface of the sample with loose interface will be looser, thereby reducing the glass transition. This can also be explained by the greatly reduced glass transition temperature Tg of the comparative example in the table and the dimensional stability several times lower than that of the embodiment. It can be seen that the Tg of the three groups of embodiments is much higher than that of the comparative example 1 without any modification, indicating that the modification method in the embodiment can improve the glass transition temperature of the composite material. Similar to the analysis in the previous part, the appropriate dopamine modification concentration (0.2g/500ml), irradiation intensity (400KGy), epoxy dopamine mixed solution concentration (0.2g dopamine, 0.25g epoxy resin E51/ 500ml acetone) can also achieve the best modification effect; the Tg and dimensional stability of Comparative Examples 2, 4 and 5 are slightly better than those of Comparative Example 1, but have a certain degree of decrease compared with several groups of experimental examples. The embodiment is compared with Comparative Example 2, which shows that irradiation is more conducive to the better infiltration of the coated dopamine and the resin matrix on the fiber surface, avoiding a certain degree of agglomeration; Comparative Example 4 shows that insufficient resin content will also lead to performance degradation, Comparative Example 5 shows that the addition of epoxy is conducive to the improvement of resin flexibility and the interface with the fiber, and Comparative Example 3 shows that the degree of resin curing has a greater impact on Tg, and Comparative Example 3 is that insufficient curing temperature will lead to a significant decrease in Tg and dimensional stability.

3. Dielectric properties of composite materials

The dielectric properties of the composite material were tested in the test frequency range of 1 kHz to 1 MHz. The dielectric constant and dielectric loss of the composite material in this frequency range were tested. The test results are shown in Table 5:

Table 5 Dielectric performance test results

The dielectric properties of fiber reinforced composites are mainly affected by the molecular polarity of the matrix and the interface polarization of the composite. In this work, the influence of interface polarization is the most important factor. From Table 5, dielectric properties with a change trend similar to that of mechanical properties can be obtained, which shows that excellent interface modification can effectively improve the dielectric properties, so that the composite material has a lower dielectric constant and dielectric loss. It is worth noting that due to the change in the degree of curing, the high-polarity cyano group in phthalonitrile is reduced, and the introduced nano-ZnO part will also affect the dielectric properties of the material to a certain extent. For Comparative Example 3, a large number of unreacted polar groups such as cyano groups lead to a larger polarity of the system. At this time, molecular polarity is dominant, and Comparative Example 3 has a higher dielectric constant and dielectric loss.

In summary, after multi-stage modification of basalt fiber cloth, the comprehensive performance of the composite material is significantly better than that of the composite material synthesized by unmodified fiber cloth, indicating that the modification of fiber cloth effectively improves the interfacial bonding force between fiber cloth and resin matrix, and improves the performance of the composite material; firstly, dopamine is used as an organic source. After irradiation, dopamine produces more active sites, which is conducive to the growth of zinc oxide. Compared with direct irradiation of basalt fiber cloth, more active sites can be produced, making zinc oxide grow more firmly and not easy to fall off; zinc oxide nanowires can roughen the fiber cloth, It is beneficial to physical entanglement and improves the bonding between the basalt fiber cloth and the cyano resin; finally, dopamine and epoxy resin are coated together, which is beneficial to further improve the interface strength and avoid separate coating and stratification. The high adhesion of dopamine is used to improve the interface effect. The epoxy resin and the cyano resin containing benzoxazine form a chemical cross-linking structure to improve the mechanical strength and heat resistance. The amino group and phenolic hydroxyl group in the dopamine finally coated on the modified basalt fiber cloth of the present invention can catalyze the polymerization reaction of thermosetting resin, reduce the resin curing temperature, increase the functional group conversion rate, and reduce the curing reaction conditions.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (5)

1. The modified basalt fiber reinforced cyano resin composite material is characterized in that the composite material is prepared from cyano resin containing benzoxazine and modified basalt fiber cloth;

The modified basalt fiber cloth is prepared by the following steps:

s101, taking basalt fiber cloth and treating the basalt fiber cloth in an oven for 2-3 hours;

S102, placing the basalt fiber cloth processed in the step S101 in a dopamine solution, standing at room temperature, soaking for 2-4 hours, taking out the basalt fiber cloth, and drying at 70 ℃ for 2 hours; the concentration of the dopamine solution is 0.1-0.5g/L;

s103, carrying out irradiation treatment on the basalt fiber cloth dried in the step S102; the irradiation dose of the irradiation treatment is 100KGy-800KGy;

s104, respectively preparing zinc acetate ethanol solution and sodium hydroxide ethanol solution, mixing the two solutions, adding ethanol for ultrasonic dispersion, arranging irradiated basalt fibers therein, standing in a water bath at 60 ℃ for 30min for reaction, taking out and drying, and annealing in an air atmosphere at 200 ℃ for 10min to obtain basalt fiber cloth coated with a ZnO seed layer;

s105, adding zinc nitrate and hexamethylenetetramine into deionized water, stirring and dissolving, arranging basalt fibers coated by a ZnO seed layer in the step S104, standing in a water bath at 90 ℃ for reaction for 2 hours, taking out and drying to obtain ZnO modified basalt fiber cloth;

S106, preparing an acetone solution containing dopamine and epoxy resin E51, and standing the ZnO modified basalt fiber cloth obtained in the step S105 for 2-3 hours to obtain the modified basalt fiber cloth; the total weight of the dopamine and the epoxy resin E51 accounts for 0.3-2% of the weight of the basalt fiber cloth;

The composite material is prepared through the following preparation steps:

s201, coating cyano resin glue solution containing benzoxazine on the modified basalt fiber cloth, and drying at 160 ℃ for half an hour to obtain prepreg cloth; the solid content of the cyano resin glue solution is 60%;

s202, preheating the prepreg cloth obtained in the step S201 for 5 minutes at 240 ℃ without increasing pressure, starting a hot press when the resin on the prepreg cloth is changed into a flowing state, hot-pressing for 1h under the conditions of the temperature of 240 ℃ and the pressure of 5MPa, then heating to 280 ℃ under the condition that the pressure is unchanged, and hot-pressing for 0.5h to obtain the modified basalt fiber reinforced cyano resin composite material.

2. The modified basalt fiber-reinforced cyano-resin composite of claim 1, wherein in step S101, the temperature of the oven is 300 ℃ to 350 ℃.

3. The modified basalt fiber-reinforced cyano-resin composite of claim 1, wherein in step S102, the pH of said dopamine solution is 8.4.

4. The modified basalt fiber-reinforced cyano-resin composite material of claim 1, wherein in step S201, the preparation method of the benzoxazine-containing cyano-resin glue solution is as follows: n, N-dimethylformamide and toluene are used as solvents, bisphenol A, formaldehyde and 3-aminophenyl-phthalonitrile are used as raw materials, magnetic stirring is carried out for 5 hours at the temperature of 80 ℃, benzoxazine-containing phthalonitrile resin glue solution is obtained through reaction, and the solid content is adjusted to 60%.

5. The modified basalt fiber-reinforced cyano-resin composite material of claim 1, wherein in step S201, the weight ratio of the modified basalt fiber cloth to the benzoxazine-containing cyano-resin glue solution is 5.5:4.5.