Explosion-proof resin composite material and preparation method thereof

Abstract

The invention discloses an explosion-proof resin composite material and a preparation method thereof, and belongs to the technical field of high-molecular compound compositions, the explosion-proof resin composite material comprises the following components by mass: 80-100 parts of epoxy resin, 10-15 parts of wave-absorbing modified glass fiber, 5-8 parts of a flame retardant, 0.3-0.4 part of zinc stearate and 0.2-0.3 part of an antioxidant; the raw materials are added into a mixing mill to be stirred and mixed and then added into a mold to be subjected to hot press molding to obtain the anti-explosion resin composite material. According to the prepared explosion-proof resin composite material, the porous nickel-based carbon material and the graphene nanosheets are compounded to prepare the composite MOF graphene powder, the dispersed composite MOF graphene powder is fixed on the surface of the high-silica glass fiber through the high-temperature carbonization effect, and the wave-absorbing modified glass fiber with the wave-absorbing capacity is obtained. Therefore, the explosion-proof resin composite material has the wave-absorbing property, and the mechanical property of the explosion-proof resin material is also improved by doping the graphene nanosheets.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer compound compositions, and particularly relates to an explosion-proof resin composite material and a preparation method thereof. Background Art

[0002] Resin materials are widely used in building materials in various industries. Among them, in the application of factory building materials in industries such as chemical engineering and petroleum, the building materials are required to have certain explosion-proof properties. The explosion-proof modified resin has excellent heat resistance, durability, barrier properties, and good mechanical strength, and is widely used in fields such as explosion-proof buildings, storage facilities, and chemical equipment. The polymer structure of the explosion-proof modified resin can effectively isolate the fire source, prevent gas leakage and explosion. The prior art usually uses glass fiber modified resin with high strength to obtain an explosion-proof resin material with excellent explosion-proof performance.

[0003] The Chinese patent application with the publication number CN118290958A discloses a glass fiber modified explosion-proof, wear-resistant and corrosion-resistant composite resin manhole cover and a preparation method thereof. By adding polyethyleneimine as a flexible protective layer and reacting with dopamine, and taking advantage of the good compatibility between polyethyleneimine and the resin, the glass fiber is dispersed in the resin. The prepared composite resin manhole cover has advantages such as high compressive and flexural strength, high flame retardancy, etc., and has good explosion-proof performance.

[0004] However, with the development of factory intelligence, more and more factories adopt electric control and automated intelligent production. During the automated control process, a large amount of electromagnetic signals will be generated, resulting in electromagnetic pollution and affecting the intelligent production of the entire factory. Therefore, it is necessary to dope wave-absorbing materials in building materials to reduce the influence brought by electromagnetic pollution.

[0005] The Chinese patent application with the publication number CN108045060A discloses an explosion-proof broadband wave-absorbing composite material and a preparation method thereof. An explosion-proof skin is prepared by quartz fiber and unsaturated resin, and the broadband sandwich wave-absorbing material and the explosion-proof skin are successively adhered to the reflection bottom plate to obtain an explosion-proof broadband wave-absorbing composite material, which has both explosion-proof function and broadband wave-absorbing function. However, this scheme physically adheres the explosion-proof resin and the wave-absorbing material, and there are large performance differences between the two materials, reducing the physical properties of the composite material and having low practicability. Summary of the Invention

[0006] The purpose of the present invention is to solve how to improve the wave-absorbing performance of the explosion-proof resin, and to provide an explosion-proof resin composite material and a preparation method thereof.

[0007] In the present invention, graphene oxide nanosheets and Ni-MOF are compounded by phosphorylated lignin. Through high-temperature carbonization, the phosphorylated lignin is carbonized and the graphene oxide nanosheets and Ni-MOF are fixed on the surface of glass fiber, and a nickel-based carbon material is formed, which synergistically improves the wave-absorbing ability of the explosion-proof resin with the graphene oxide nanosheets.

[0008] The object of the present invention can be achieved by the following technical solutions:

[0009] An explosion-proof resin composite material, by mass, comprises the following components:

[0010] 80-100 parts of epoxy resin, 10-15 parts of wave-absorbing modified glass fiber, 5-8 parts of flame retardant, 0.3-0.4 parts of zinc stearate and 0.2-0.3 parts of antioxidant.

[0011] The flame retardant is one of aluminum hydroxide and magnesium hydroxide.

[0012] The antioxidant is one of hindered phenol antioxidants and phosphite antioxidants.

[0013] Further, the wave-absorbing modified glass fiber is prepared by the following steps:

[0014] In a reaction kettle, high-silica glass fiber, composite MOF graphene powder and deionized water are ultrasonically mixed for 5-6 h, and the precipitate is obtained by centrifugal filtration. After the precipitate is vacuum dried at 60-70 °C, it is placed in a tube furnace. Under nitrogen protection, it is heated to 700-800 °C at a rate of 5 °C / min, kept warm for 1.5-2 h, and the wave-absorbing modified glass fiber is obtained after cooling.

[0015] Further, the dosage ratio of high-silica glass fiber, composite MOF graphene powder and deionized water is 10-15 g: 0.8-1 g: 100-150 mL.

[0016] Further, the composite MOF graphene powder is prepared by the following steps:

[0017] In a reaction kettle, nickel nitrate hexahydrate and 2-aminoterephthalic acid are dissolved in DMF and deionized water, lignin / graphene powder is added, and the temperature is raised to 120-130 °C for reaction for 20-24 h. The precipitate is centrifuged and separated, and the precipitate is washed with DMF and ethanol, and then vacuum dried to obtain the composite MOF graphene powder.

[0018] Further, the dosage ratio of nickel nitrate hexahydrate, 2-aminoterephthalic acid, DMF, deionized water and lignin / graphene powder is 3-5 g: 3-4 g: 200-250 mL: 100-150 mL: 0.5-0.6 g.

[0019] Further, the lignin / graphene powder is prepared by the following steps:

[0020] Ultrasonically disperse phosphorylated lignin in deionized water in a reaction kettle, add graphene oxide nanosheets, stir and react for 10 - 12 h, centrifuge to collect the precipitate, and vacuum dry at 60 - 70 °C for 10 - 12 h to obtain lignin / graphene powder.

[0021] Furthermore, the dosage ratio of phosphorylated lignin, deionized water and graphene oxide nanosheets is 2 - 2.5 g : 200 - 250 mL : 1 - 1.2 g.

[0022] Furthermore, the phosphorylated lignin is prepared by the following steps:

[0023] Dissolve alkaline lignin powder in tetrahydrofuran in a reaction kettle, add 85 wt% phosphoric acid solution to the reaction kettle, stir magnetically at 30 - 40 °C for 3 - 4 h, remove the solvent by reduced pressure distillation after cooling to obtain a precipitate, wash the precipitate, and vacuum dry to obtain phosphorylated lignin.

[0024] Furthermore, the dosage ratio of alkaline lignin powder, tetrahydrofuran and phosphoric acid is 1 - 2 g : 50 - 60 mL : 0.8 - 1 g.

[0025] A preparation method of an explosion-proof resin composite material includes the following steps:

[0026] Add epoxy resin, wave-absorbing modified glass fiber, flame retardant, zinc stearate and antioxidant into a mixer and stir to mix, obtain a premix, add the premix into a mold, heat and reflux react at 150 - 170 °C for 3 - 6 h and hot press to form, and obtain the explosion-proof resin composite material after curing for 20 - 24 h.

[0027] Advantages of the present invention:

[0028] (1) The explosion-proof resin composite material prepared by the present invention is prepared by compounding porous nickel-based carbon material and graphene oxide nanosheets to obtain composite MOF graphene powder, and the dispersed composite MOF graphene powder is fixed on the surface of high-silica glass fiber through high-temperature carbonization, so as to obtain wave-absorbing modified glass fiber with wave-absorbing ability, thereby enabling the explosion-proof resin composite material to have wave-absorbing performance, and the doping of graphene oxide nanosheets also improves the mechanical properties of the explosion-proof resin material.

[0029] (2) The preparation method of the present invention uses phosphorylated lignin as a connecting substance. By compounding phosphorylated lignin with graphene oxide nanosheets, Ni-MOF is combined on the surface of graphene oxide nanosheets under the action of phosphorylated cellulose to form a composite MOF powder with uniform composite degree. The carbon structure formed by the carbonization of lignin is used to fix the composite MOF powder on the surface of high-silica glass fiber, which better improves the wave-absorbing performance and mechanical properties of the explosion-proof resin composite material. Specific embodiments

[0030] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0031] Example 1: A preparation method of an explosion-proof resin composite material, comprising the following steps:

[0032] S1. Dissolve 1 g of alkaline lignin powder passed through a 100-mesh sieve in 50 mL of tetrahydrofuran in a reaction kettle, add 0.8 g of 85 wt% phosphoric acid solution to the reaction kettle, stir magnetically at 30 °C for 3 h, remove the solvent by reduced pressure distillation after cooling, wash the precipitate with deionized water, and vacuum dry at 90 °C for 3 h to obtain phosphorylated lignin.

[0033] S2. Ultrasonically disperse 2 g of phosphorylated lignin in 200 mL of deionized water in a reaction kettle, add 1 g of graphene oxide nanosheets, stir and react for 10 h, centrifuge to collect the precipitate, and vacuum dry at 60 °C for 10 h to obtain lignin / graphene powder.

[0034] S3. Dissolve 3 g of nickel nitrate hexahydrate and 3 g of 2-aminoterephthalic acid in 200 mL of DMF and 100 mL of deionized water in a reaction kettle, add 0.5 g of lignin / graphene powder, heat up to 120 °C and react for 20 h, centrifuge to separate the precipitate, wash the precipitate with DMF and ethanol, and vacuum dry at 60 °C for 10 h to obtain composite MOF graphene powder.

[0035] S4. Ultrasonically mix 10 g of high-silica glass fiber, 0.8 g of composite MOF graphene powder and 100 mL of deionized water in a reaction kettle for 5 h, centrifuge and filter to obtain the precipitate, vacuum dry the precipitate at 60 °C and then place it in a tube furnace, heat up to 700 °C at a rate of 5 °C / min under nitrogen protection, keep the temperature for 1.5 h, and cool to obtain wave-absorbing modified glass fiber.

[0036] S5. Add 80 g of epoxy resin, 10 g of wave-absorbing modified glass fiber, 5 g of aluminum hydroxide, 0.3 g of zinc stearate and 0.2 g of hindered phenol antioxidant to a mixer and stir and mix to obtain a premix. Add the premix to a mold, heat and reflux at 150 °C for 3 h for hot pressing and molding, and cure for 20 h to obtain an explosion-proof resin composite material.

[0037] Example 2: A preparation method of an explosion-proof resin composite material, comprising the following steps:

[0038] S1. Dissolve 1.5 g of alkaline lignin powder passed through a 100-mesh sieve in 55 mL of tetrahydrofuran in a reaction kettle. Add 0.9 g of 85 wt% phosphoric acid solution to the reaction kettle, stir magnetically at 35 °C for 3.5 h. After cooling, remove the solvent by vacuum distillation to obtain a precipitate. Wash the precipitate with deionized water and vacuum dry it at 92.5 °C for 3.5 h to obtain phosphorylated lignin.

[0039] S2. Ultrasonically disperse 2.25 g of phosphorylated lignin in 225 mL of deionized water in a reaction kettle. Add 1.1 g of graphene oxide nanosheets, stir and react for 11 h, centrifuge to collect the precipitate, and vacuum dry it at 65 °C for 11 h to obtain lignin / graphene powder.

[0040] S3. Dissolve 4 g of nickel nitrate hexahydrate and 3.5 g of 2-aminoterephthalic acid in 225 mL of DMF and 125 mL of deionized water in a reaction kettle. Add 0.55 g of lignin / graphene powder, heat up to 125 °C and react for 22 h, centrifuge to separate the precipitate, wash the precipitate with DMF and ethanol, and vacuum dry it at 65 °C for 11 h to obtain composite MOF graphene powder.

[0041] S4. Ultrasonically mix 12.5 g of high-silica glass fiber, 0.9 g of composite MOF graphene powder and 125 mL of deionized water in a reaction kettle for 5.5 h, centrifuge and filter to obtain a precipitate. Vacuum dry the precipitate at 65 °C and then place it in a tubular furnace. Under nitrogen protection, heat it up to 750 °C at a rate of 5 °C / min, hold for 1.75 h, and cool to obtain wave-absorbing modified glass fiber.

[0042] S5. Add 90 g of epoxy resin, 12.5 g of wave-absorbing modified glass fiber, 6.5 g of aluminum hydroxide, 0.35 g of zinc stearate and 0.25 g of hindered phenol antioxidant to a mixer and stir to mix, obtaining a premix. Add the premix to a mold, heat and reflux at 160 °C for 4.5 h for hot pressing and molding, and cure for 22 h to obtain an explosion-proof resin composite.

[0043] Example 3: A preparation method of an explosion-proof resin composite, comprising the following steps:

[0044] S1. Dissolve 2 g of alkaline lignin powder passed through a 100-mesh sieve in 60 mL of tetrahydrofuran in a reaction kettle. Add 1 g of 85 wt% phosphoric acid solution to the reaction kettle, stir magnetically at 40 °C for 4 h. After cooling, remove the solvent by vacuum distillation to obtain a precipitate. Wash the precipitate with deionized water and vacuum dry it at 95 °C for 4 h to obtain phosphorylated lignin.

[0045] S2. Ultrasonically disperse 2.5 g of phosphorylated lignin in 250 mL of deionized water in a reaction kettle. Add 1.2 g of graphene oxide nanosheets, stir and react for 12 h, centrifuge to collect the precipitate, and vacuum dry it at 70 °C for 12 h to obtain lignin / graphene powder.

[0046] S3. In a reactor, 5 g of nickel nitrate hexahydrate and 4 g of 2-aminoterephthalic acid were dissolved in 250 mL of DMF and 150 mL of deionized water, and 0.6 g of lignin / graphene powder was added. The temperature was raised to 130° C. and the reaction was carried out for 24 h. The precipitate was separated by centrifugation, and the precipitate was washed with DMF and ethanol. The composite MOF graphene powder was obtained by vacuum drying at 70° C. for 12 h.

[0047] S4. In a reactor, 15 g of high-silica glass fiber, 1 g of composite MOF graphene powder and 150 mL of deionized water were ultrasonically mixed for 6 h, and the precipitate was obtained by centrifugal filtration. The precipitate was vacuum dried at 70 °C and placed in a tubular furnace. The temperature was increased to 800 °C at a rate of 5 °C / min under nitrogen protection, and the temperature was kept for 2 h. After cooling, the wave-absorbing modified glass fiber was obtained.

[0048] S5. Add 100g epoxy resin, 15g wave-absorbing modified glass fiber, 8g magnesium hydroxide, 0.4g zinc stearate and 0.3g phosphite antioxidant into a mixer and stir to obtain a premix. Add the premix into a mold, heat to reflux at 170°C for 6h, and perform hot pressing to form the mold. After curing for 24h, obtain an explosion-proof resin composite material.

[0049] Principle of the invention:

[0050] The invention modifies alkaline lignin with phosphoric acid, wherein the hydroxyl groups on the surface of the alkaline lignin are conducive to the grafting modification of the phosphoric acid groups, and the phosphoric acid groups of the phosphorylated lignin are reacted with the hydroxyl groups on the surface of the graphene oxide nanosheets for grafting, and the surface of the lignin and the graphene oxide nanosheets also have a hydrogen bond effect, the phosphorylated lignin is composited with the graphene oxide nanosheets, and then Ni-MOF is in situ generated on the surface of the lignin / graphene powder, and the amino groups in the ligand 2-aminoterephthalic acid are used to improve the binding ability of Ni-MOF on the surface of the phosphorylated lignin, so as to obtain a composite MOF powder composited with Ni-MOF, phosphorylated lignin and graphene oxide nanosheets.

[0051] By compounding the composite MOF powder with high-temperature resistant and high-strength high-silica glass fiber and then sintering at high temperature, the phosphorylated cellulose in the composite MOF graphene powder is carbonized on the surface of the high-silica glass fiber, thereby improving the bonding strength between the composite MOF graphene powder and the high-silica glass fiber and avoiding the agglomeration phenomenon when the composite MOF graphene powder is mixed with epoxy resin. At the same time, the high temperature carbonizes the ligand of Ni-MOF to derive into a porous nickel-based carbon material, which has good electromagnetic wave absorption ability and is dispersed on the surface of the high-silica glass fiber, thereby improving the wave absorption performance of the high-silica glass fiber.

[0052] High temperature also causes the reduction of graphene oxide nanosheets to form graphene nanosheets. Graphene nanosheets have a large specific surface area and can effectively serve as microwave absorbing materials to enhance the microwave absorbing ability of the resin. At the same time, they can improve the mechanical properties of the resin, effectively enhancing the impact resistance and tensile strength of the resin, improving the explosion-proof ability of the resin, and synergistically acting with nickel-based carbon materials to jointly enhance the microwave absorbing ability of the resin.

[0053] Comparative Example 1: The difference from Example 1 is that in S2, alkaline lignin powder is used to replace phosphorylated lignin to prepare an explosion-proof resin composite material.

[0054] Comparative Example 2: The difference from Example 1 is that in S3, graphene oxide nanosheets are used to replace lignin / graphene powder to prepare an explosion-proof resin composite material.

[0055] Comparative Example 3: The difference from Example 1 is that in S4, 0.5 g of lignin / graphene powder and 0.3 g of zirconia nanopowder are used to replace the composite MOF graphene powder to prepare an explosion-proof resin composite material.

[0056] The sources of some reagents in the comparative examples and examples are as follows:

[0057] The CAS number of the alkaline lignin powder is 9005-53-2, with a purity of 99%, and it is purchased from Hubei Dalili Chemical Co., Ltd.

[0058] The sheet diameter of the graphene oxide nanosheets: 0.5 - 5 μm, thickness: 0.8 - 1.2 nm, and it is purchased from Suxianfeng Nanoscience and Technology Co., Ltd.

[0059] The high silica glass fiber is a chopped fiber with a specification of 9 - 15 μm, and it is purchased from Lianyungang Rongbai New Materials Co., Ltd.

[0060] Perform performance tests on the explosion-proof resin composites prepared in Examples 1 - 3 and Comparative Examples 1 - 3. Test the compressive strength of the specimens according to the standard GBJ81 - 1985, test the impact resistance of the specimens according to the simply supported beam impact test method of the standard GB / T1043.1 - 2008, and test the electromagnetic parameters of the samples according to the coaxial test method. The model of the test machine is the N5241BPNA-X type microwave network analyzer, and the test frequency range is 2 - 18 GHz.

[0061] The results are shown in Table 1:

[0062] Table 1: Performance test results table of explosion-proof resin composites

[0063] Project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Compressive strength (MPa) 78 81 82 72 68 63 <![CDATA[Impact strength (kJ / m 2 )]]> 102 103 105 92 90 86 Effective absorption bandwidth (GHz) 5.43 5.28 5.12 5.81 6.72 7.41 Minimum reflectivity (dB) -33.6 -33.9 -34.0 -30.1 -27.4 -24.8

[0064] As can be seen from Table 1, the explosion-proof resin composite material prepared by the present invention has high compressive strength and high impact strength, indicating good explosion-proof performance, and has a low effective absorption bandwidth and a small minimum reflectivity, indicating that the explosion-proof resin composite material prepared by the present invention has good wave absorption ability.

[0065] In Comparative Example 1, since the alkaline lignin powder was not phosphorylated and modified, the degree of composite of the alkaline lignin powder and the graphene oxide nanosheets was low, and the degree of composite of Ni-MOF and the lignin / graphene powder was also reduced, resulting in a decrease in the performance of the explosion-proof resin composite material prepared.

[0066] In Comparative Example 2, due to the absence of phosphorylated lignin, the degree and strength of the composite of graphene oxide nanosheets and Ni-MOF were low, and the modification effect on high-silica glass fibers was reduced. When the wave-absorbing modified glass fibers were mixed with epoxy resin, the composite MOF graphene powder was easily detached from the surface of the high-silica glass fibers, resulting in a lower improvement in the mechanical properties and wave absorption properties of the explosion-proof resin composite material.

[0067] In Comparative Example 3, since zirconium dioxide nanopowder was used to replace Ni-MOF, the formed nickel-based carbon material did not have a porous structure, resulting in a small improvement in wave absorption ability, and the degree of combination of zirconium dioxide nanopowder and lignin / graphene powder was low, and the synergistic effect between zirconium dioxide and graphene nanosheets was small.

[0068] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An explosion-proof resin composite material, characterized in that: By mass, it contains the following components: 80-100 parts of epoxy resin, 10-15 parts of wave-absorbing modified glass fiber, 5-8 parts of flame retardant, 0.3-0.4 parts of zinc stearate and 0.2-0.3 parts of antioxidant; The flame retardant is one of aluminum hydroxide and magnesium hydroxide; The antioxidant is one of a hindered phenol antioxidant and a phosphite antioxidant.

2. The explosion-proof resin composite material according to claim 1, characterized in that: The wave-absorbing modified glass fiber is prepared by the following steps: In a reaction kettle, high silica glass fiber, composite MOF graphene powder and deionized water are ultrasonically mixed for 5-6 hours, centrifugally filtered to obtain a precipitate, the precipitate is vacuum dried at 60-70°C and placed in a tubular furnace, and heated to 700-800°C at a rate of 5°C / min under nitrogen protection, kept warm for 1.5-2 hours, and cooled to obtain the wave-absorbing modified glass fiber.

3. The explosion-proof resin composite material according to claim 2, characterized in that: The usage ratio of the high-silica glass fiber, the composite MOF graphene powder and the deionized water is 10-15 g: 0.8-1 g: 100-150 mL.

4. The explosion-proof resin composite material according to claim 3, characterized in that: The composite MOF graphene powder is prepared by the following steps: In a reaction kettle, nickel nitrate hexahydrate and 2-aminoterephthalic acid are dissolved in DMF and deionized water, lignin / graphene powder is added, the temperature is raised to 120-130° C. and the reaction is carried out for 20-24 hours, the precipitate is separated by centrifugation, the precipitate is washed with DMF and ethanol, and the composite MOF graphene powder is obtained by vacuum drying.

5. The explosion-proof resin composite material according to claim 4, characterized in that: The usage ratio of the nickel nitrate hexahydrate, 2-aminoterephthalic acid, DMF, deionized water and lignin / graphene powder is 3-5 g: 3-4 g: 200-250 mL: 100-150 mL: 0.5-0.6 g.

6. The explosion-proof resin composite material according to claim 5, characterized in that: The lignin / graphene powder is prepared by the following steps: In a reactor, the phosphorylated lignin is ultrasonically dispersed in deionized water, graphene oxide nanosheets are added, the reaction is stirred for 10-12 hours, the precipitate is collected by centrifugation, and the lignin / graphene powder is obtained by vacuum drying at 60-70° C. for 10-12 hours.

7. The explosion-proof resin composite material according to claim 6, characterized in that: The usage ratio of the phosphorylated lignin, deionized water and graphene oxide nanosheets is 2-2.5 g: 200-250 mL: 1-1.2 g.

8. The explosion-proof resin composite material according to claim 7, characterized in that: The phosphorylated lignin is prepared by the following steps: The alkaline lignin powder is dissolved in tetrahydrofuran in a reaction kettle, and 85 wt% phosphoric acid solution is added to the reaction kettle, and magnetic stirring is performed at 30-40° C. for 3-4 hours. After cooling, the solvent is removed by vacuum distillation to obtain a precipitate, and the precipitate is washed and vacuum dried to obtain phosphorylated lignin.

9. The explosion-proof resin composite material according to claim 8, characterized in that: The usage ratio of the alkaline lignin powder, tetrahydrofuran and phosphoric acid is 1-2g:50-60mL:0.8-1g.

10. A method for preparing an explosion-proof resin composite material, characterized in that: The steps include: The epoxy resin, wave-absorbing modified glass fiber, flame retardant, zinc stearate and antioxidant are added into a mixer and stirred to obtain a premix, the premix is ​​added into a mold, heated to reflux at 150-170° C. for 3-6 hours, hot-pressed, and cured for 20-24 hours to obtain an explosion-proof resin composite material.