Radiation-resistant composite epoxy resin film and preparation method thereof

Abstract

The invention belongs to the technical field of composite materials, and particularly relates to an irradiation-resistant composite epoxy resin film and a preparation method thereof, and the irradiation-resistant composite epoxy resin film is composed of a modified epoxy resin matrix, carbon fibers, modified nano silicon dioxide and a curing agent. The mass ratio of the carbon fibers in the irradiation-resistant composite epoxy resin film is 0.5%-5%, the mass ratio of the modified nano silicon dioxide in the irradiation-resistant composite epoxy resin film is 1%-8%, and the mass ratio of the curing agent to the modified epoxy resin matrix is (5-8): 10. According to the radiation-resistant composite epoxy resin film disclosed by the invention, the bisphenol A epoxy resin matrix is subjected to dual modification, and the carbon fibers and the modified nano silicon dioxide filler are added, so that the dielectric property and the mechanical property of the radiation-resistant composite epoxy resin film are improved, the radiation resistance of the material is improved, and the radiation resistance of the material is improved after high-strength radiation. And the performance of the composite epoxy resin film before irradiation can be basically maintained.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, specifically relating to a radiation-resistant composite epoxy resin film and its preparation method. Background Technology

[0002] Epoxy resin, as a matrix for composite materials, is widely used in various fields such as electronics, electrical engineering, and aerospace in the form of structural or functional components. It possesses excellent heat resistance, damp heat resistance, impact resistance, adhesion, and interfacial properties. However, the insulation and mechanical properties of epoxy resin matrix composites decrease after irradiation, thus affecting their application. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a radiation-resistant composite epoxy resin film and its preparation method. The bisphenol A epoxy resin matrix is ​​modified in two ways, and carbon fibers and modified nano-silica fillers are added. After being subjected to high-intensity irradiation, the film can basically maintain its performance before irradiation.

[0004] The present invention is specifically implemented through the following technical solution.

[0005] A radiation-resistant composite epoxy resin film is formed by curing a modified epoxy resin matrix, carbon fibers, modified nano-silica, and a curing agent. The carbon fibers account for 0.5% to 5% of the mass of the radiation-resistant composite epoxy resin film, the modified nano-silica accounts for 1% to 8% of the mass of the radiation-resistant composite epoxy resin film, and the remainder consists of curing agent and modified epoxy resin matrix. The mass ratio of curing agent to modified epoxy resin matrix is ​​5 to 8:10, totaling 100%.

[0006] The preparation method of the modified epoxy resin matrix includes the following steps: Modified epoxy resin was prepared by using bisphenol A type epoxy resin, 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, and eugenol as raw materials in an organic solvent under an inert gas atmosphere and in the presence of triphenylphosphine catalysis, through addition and substitution reactions.

[0007] The method for preparing modified nano-silica is as follows: using water as a dispersant, a mixed dispersion system of nano-silica and oleic acid-based imidazoline quaternary ammonium salt is prepared; the mixed dispersion system is kept at 75~85℃ to prepare modified nano-silica; more specifically, the nano-silica is uniformly dispersed in deionized water and ultrasonically treated for 30~60 minutes, then heated to 75℃~85℃, and the aqueous solution of oleic acid-based imidazoline quaternary ammonium salt is added dropwise over 20~30 minutes. After the addition is complete, the temperature is kept at 75℃~85℃ for 2.5~3.5 hours. After separating the solid particles, the mixture is washed with deionized water, and the solid particles are collected to obtain modified nano-silica.

[0008] The chemical structure of oleic acid-based imidazoline quaternary ammonium salt is as follows: .

[0009] The aforementioned radiation-resistant composite epoxy resin film, through dual modification of the bisphenol A epoxy resin matrix and the addition of carbon fiber and modified nano-silica filler, improves the dielectric and mechanical properties of the radiation-resistant composite epoxy resin film, thereby enhancing the material's radiation resistance. After high-intensity irradiation, it can basically maintain the performance of the composite epoxy resin film before irradiation, with minimal performance degradation.

[0010] In a preferred embodiment of the present invention, in the preparation method of modified nano-silica, the mass ratio of nano-silica to oleic acid-based imidazoline quaternary ammonium salt is 2:0.8~1.5.

[0011] The aforementioned radiation-resistant composite epoxy resin film exhibits superior radiation resistance and dielectric properties.

[0012] In a preferred embodiment of the present invention, the mass ratio of carbon fiber in the composite epoxy resin film is 1% to 3%, and the mass ratio of modified nano-silica in the composite epoxy resin film is 2.5% to 6%.

[0013] Preferably, 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide and eugenol are first added to an organic solvent containing bisphenol A type epoxy resin and mixed at 140℃~160℃. Then, triphenylphosphine is added at 185℃~195℃ and kept at this temperature for 2.5h~3.5h.

[0014] Specifically, the following steps are included: (1) Under inert gas protection, the bisphenol A type epoxy resin is heated to 140℃~160℃, and 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide and eugenol are slowly added. The molar ratio of 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide and eugenol is 1~4:1~4, and the mass ratio of bisphenol A type epoxy resin to 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide is 100:25~30.

[0015] (2) The temperature is then raised to 185℃~195℃, and triphenylphosphine is added as a catalyst. The reaction is then maintained at this temperature for 2.5 hours~3.5 hours; preferably, the temperature is 190℃ and the reaction time is 3 hours. The amount of triphenylphosphine used is 0.8%~1.2% of the mass of bisphenol A epoxy resin. The preparation mechanism of the modified epoxy resin is as follows: .

[0016] (3) Remove the reaction solvent to obtain the modified epoxy resin.

[0017] In a preferred embodiment of the present invention, the reaction in the preparation method of the modified epoxy resin is carried out in a dichloromethane solvent.

[0018] In a preferred embodiment of the present invention, the curing agent is 4,4'-diaminodiphenylmethane, abbreviated as DDM.

[0019] In a preferred embodiment of the present invention, the length of the carbon fiber does not exceed 3 mm.

[0020] In a preferred embodiment of the present invention, the method for preparing the radiation-resistant composite epoxy resin film includes the following steps: (1) After mixing modified epoxy resin, modified nano silica and carbon fiber with a length not exceeding 3 mm in a weight ratio, add curing agent and mix well to obtain a mixture.

[0021] (2) After degassing the mixture in a vacuum oven at 85℃~90℃, the temperature is raised to 98℃~105℃ and cured for 2~5 hours to obtain a radiation-resistant composite epoxy resin film.

[0022] More specifically, the preparation method of the radiation-resistant composite epoxy resin film includes the following steps: (a) After mixing modified epoxy resin, modified nano silica and carbon fiber with a length not exceeding 3 mm in a weight ratio, a curing agent is added and mixed evenly to obtain a mixture.

[0023] The preparation method of the modified epoxy resin matrix includes the following steps: Modified epoxy resin was prepared by using bisphenol A type epoxy resin, 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, and eugenol as raw materials in an organic solvent under an inert gas atmosphere and in the presence of triphenylphosphine catalysis, through addition and substitution reactions.

[0024] The method for preparing modified nano-silica includes the following steps: using water as a dispersant, a mixed dispersion system of nano-silica and oleic acid-based imidazoline quaternary ammonium salt is prepared; the mixed dispersion system is kept at 75℃~85℃ to prepare modified nano-silica.

[0025] The chemical structure of oleic acid-based imidazoline quaternary ammonium salt is as follows: .

[0026] The curing agent is 4,4'-diaminodiphenylmethane.

[0027] (b) After degassing the mixture in a vacuum oven at 85°C to 90°C, the temperature is raised to 98°C to 105°C and cured for 2 to 5 hours to obtain a radiation-resistant composite epoxy resin film.

[0028] The carbon fiber accounts for 0.5% to 5% of the mass of the radiation-resistant composite epoxy resin film, the modified nano silica accounts for 1% to 8% of the mass of the radiation-resistant composite epoxy resin film, and the remainder is curing agent and modified epoxy resin matrix. The mass ratio of curing agent to modified epoxy resin matrix is ​​5 to 8:10, totaling 100%.

[0029] Compared with the prior art, the present invention has the following advantages: The radiation-resistant composite epoxy resin film provided by this invention improves the dielectric and mechanical properties of the composite epoxy resin film by doubly modifying the bisphenol A epoxy resin matrix and adding carbon fiber and modified nano-silica filler, thereby improving the radiation resistance of the material. After high-intensity irradiation, the composite epoxy resin film can basically maintain the properties of the composite epoxy resin film before irradiation and can be used as an insulating material. Detailed Implementation

[0030] To enable those skilled in the art to better understand and implement the technical solutions of this invention, the invention is further described below with reference to specific embodiments and data. However, the embodiments are not intended to limit the invention. Unless otherwise specified, the experimental and detection methods described in the following embodiments are conventional methods; unless otherwise specified, the reagents and materials are commercially available.

[0031] To improve the radiation resistance of epoxy resin, this invention provides a radiation-resistant composite epoxy resin film, comprising a modified epoxy resin matrix, carbon fibers, modified nano-silica, and a curing agent; wherein the mass proportion of carbon fibers in the radiation-resistant composite epoxy resin film is 0.5%~5%, the mass proportion of modified nano-silica in the radiation-resistant composite epoxy resin film is 1%~8%, and the balance is the curing agent and the modified epoxy resin matrix, and the mass ratio of the curing agent to the modified epoxy resin matrix is ​​5~8:10, totaling 100%.

[0032] The preparation method of the modified epoxy resin matrix includes the following steps: Under an inert gas atmosphere, in an organic solvent, bisphenol A type epoxy resin, 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, and eugenol were used as raw materials. Under the catalysis of triphenylphosphine, addition and substitution reactions were carried out to prepare a modified epoxy resin. The mass ratio of bisphenol A type epoxy resin to 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide was 100:25~30, the molar ratio of 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide to eugenol was 1~4:1~4, and the amount of triphenylphosphine was 0.8%~1.2% of the mass of the bisphenol A type epoxy resin. The chemical structure of the modified epoxy resin matrix obtained by the above preparation method is shown in formula (Ⅰ). (I); Where x and y are natural numbers, 5 ≤ x ≤ 40, 5 ≤ y ≤ 40, and x and y are controlled by the ratio of bisphenol A epoxy resin, 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, and eugenol in the modified epoxy resin. 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide is abbreviated as DOPO-HQ. It should be noted that the degree of reaction of each molecular chain is different during the preparation process. Therefore, the product obtained through a single preparation process includes numerous molecular chains of different lengths. Thus, in the above structure, x and y are numerical ranges. That is, the preparation method of this invention can obtain products with x and y within the above ranges.

[0033] The preparation method of modified nano-silica includes the following steps: A mixed dispersion system of nano-silica and oleic acid-based imidazoline quaternary ammonium salt was prepared using water as a dispersant; the mixed dispersion system was kept at 75℃~85℃ to prepare modified nano-silica.

[0034] The chemical structure of oleic acid-based imidazoline quaternary ammonium salt is shown in formula (II): (II).

[0035] Furthermore, it should be noted that this invention, by performing dual modification on the bisphenol A epoxy resin matrix and adding carbon fiber and modified nano-silica filler, improves the dielectric and mechanical properties of the composite epoxy resin film and enhances the material's radiation resistance. Specifically, the dual modification of the bisphenol A epoxy resin matrix refers to modifying the epoxy resin backbone with 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide and eugenol. To illustrate the advantages of the aforementioned dual modification strategy, this invention also provides a single-modified bisphenol A epoxy resin matrix, where the epoxy resin backbone is modified with either 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide or eugenol, respectively, for comparison.

[0036] Specifically, when the bisphenol A epoxy resin matrix is ​​modified with 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, the resulting structure is shown in formula (Ⅲ): (III); Where x and y are natural numbers, 5≤x≤40, 5≤y≤40.

[0037] When eugenol is used to modify the bisphenol A epoxy resin matrix, the resulting structure is shown in formula (Ⅳ): (Ⅳ); Where x and y are natural numbers, 5≤x≤40, 5≤y≤40.

[0038] A method for preparing a radiation-resistant composite epoxy resin film includes the following steps: Modified epoxy resin matrix, modified nano-silica and carbon fiber are mixed in a weight ratio, and then a curing agent is added and mixed evenly to obtain a mixture.

[0039] After degassing the mixture in a vacuum oven at 85℃~90℃, it is then heated to 98℃~105℃ and cured for 2 to 5 hours to obtain a radiation-resistant composite epoxy resin film.

[0040] The radiation-resistant composite epoxy resin film provided by this invention improves the dielectric and mechanical properties of the bisphenol A epoxy resin matrix by double modification and by adding carbon fiber and modified nano-silica filler, thereby improving the radiation resistance of the material. After high-intensity irradiation, the composite epoxy resin film can basically maintain the performance of the film before irradiation, and the performance degradation is not significant.

[0041] The invention will now be described in detail through the following embodiments and comparative examples.

[0042] Example 1 As an embodiment of the present invention, a radiation-resistant composite epoxy resin film is made of a modified epoxy resin matrix, carbon fiber, modified nano-silica and a curing agent. The curing agent is 4,4'-diaminodiphenylmethane, abbreviated as DDM, and the length of the carbon fiber does not exceed 3 mm.

[0043] The carbon fiber accounts for 3% of the mass of the radiation-resistant composite epoxy resin film, the modified nano-silica accounts for 4% of the mass of the radiation-resistant composite epoxy resin film, and the mass ratio of curing agent to modified epoxy resin matrix is ​​5:10.

[0044] The method for preparing the modified epoxy resin matrix shown in formula (Ⅰ) above includes the following steps: (1) Add bisphenol A type epoxy resin to a four-necked flask containing dichloromethane solvent. Set up a stirrer and a thermometer, stir at 90°C for 20 min to dissolve, and heat to 150°C under argon protection. Slowly add 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide and eugenol. The mass ratio of bisphenol A type epoxy resin to 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide is 100:25, and the molar ratio of 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide to eugenol is 1:1. Stir for 15 min to mix.

[0045] (2) Heat the temperature to 190°C, add triphenylphosphine as a catalyst and keep the temperature for 3 hours; the amount of catalyst is 1% of the weight of bisphenol A epoxy resin.

[0046] (3) Remove the reaction solvent to obtain the modified epoxy resin.

[0047] The modified nano-silica was prepared as follows: nano-silica was uniformly dispersed in deionized water and ultrasonically treated for 40 minutes. The mass ratio of nano-silica to deionized water was 1:10. After heating to 80°C, an aqueous solution of oleic acid imidazoline quaternary ammonium salt was added dropwise over 25 minutes. The mass concentration of the aqueous solution of oleic acid imidazoline quaternary ammonium salt was 20%, and the mass ratio of oleic acid imidazoline quaternary ammonium salt to nano-silica was 2:1. After the addition was completed, the solution was kept at 80°C for 3 hours. After separating the solid particles, the solution was washed with deionized water, and the solid particles were collected and dried to obtain modified nano-silica.

[0048] The chemical structure of oleic acid-based imidazoline quaternary ammonium salt is as follows: .

[0049] The method for preparing the radiation-resistant composite epoxy resin film in this embodiment includes the following steps: Modified epoxy resin, modified nano-silica, and carbon fibers with a length not exceeding 3 mm are mixed in a weight ratio, and then a curing agent is added and mixed evenly to obtain a mixture.

[0050] After degassing the mixture at 90°C in a vacuum oven, the temperature is raised to 100°C and cured for 2.5 hours to obtain a radiation-resistant composite epoxy resin film.

[0051] Example 2 As an embodiment of the present invention, the radiation-resistant composite epoxy resin film differs from Example 1 in that the mass ratio of bisphenol A type epoxy resin to 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide is 100:30, and the molar ratio of 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide to eugenol is 1:1.

[0052] Example 3 As an embodiment of the present invention, the radiation-resistant composite epoxy resin film differs from Example 1 in that the mass ratio of bisphenol A type epoxy resin to 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide is 100:25, and the molar ratio of 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide to eugenol is 3:2.

[0053] Example 4 As an embodiment of the present invention, the radiation-resistant composite epoxy resin film differs from Example 1 in that the mass ratio of bisphenol A type epoxy resin to 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide is 100:25, and the molar ratio of 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide to eugenol is 3:4.5.

[0054] Example 5 As an embodiment of the present invention, the difference between this embodiment and Embodiment 1 is that the mass ratio of carbon fiber in the radiation-resistant composite epoxy resin film is 3%, and the mass ratio of modified nano-silica in the radiation-resistant composite epoxy resin film is 1%.

[0055] Example 6 As an embodiment of the present invention, the difference between this embodiment and Embodiment 1 is that the mass ratio of carbon fiber in the radiation-resistant composite epoxy resin film is 3%, and the mass ratio of modified nano-silica in the radiation-resistant composite epoxy resin film is 2.5%.

[0056] Example 7 As an embodiment of the present invention, the difference between this embodiment and Embodiment 1 is that the mass ratio of carbon fiber in the radiation-resistant composite epoxy resin film is 3%, and the mass ratio of modified nano-silica in the radiation-resistant composite epoxy resin film is 6%.

[0057] Example 8 As an embodiment of the present invention, the difference between this embodiment and Embodiment 1 is that the mass ratio of carbon fiber in the radiation-resistant composite epoxy resin film is 3%, and the mass ratio of modified nano-silica in the radiation-resistant composite epoxy resin film is 8%.

[0058] Comparative Example 1 As a comparative example of the present invention, this composite epoxy resin film differs from Example 1 in that: The modified epoxy resin in Example 1 was replaced with the modified epoxy resin with the structure shown in Formula (III). The preparation of the modified epoxy resin with the structure shown in Formula (III) was the same as that of the modified epoxy resin with the structure shown in Formula (I) in Example 1, except that eugenol was not added and the molar amount of eugenol was made up with 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0059] Comparative Example 2 As a comparative example of the present invention, this composite epoxy resin film differs from Example 1 in that: The modified epoxy resin in Example 1 was replaced with the modified epoxy resin with the structure shown in Formula (IV). The preparation of the modified epoxy resin with the structure shown in Formula (IV) was carried out in accordance with the preparation method of the modified epoxy resin with the structure shown in Formula (I) in Example 1, except that 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide was not added, and the molar amount of 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide was made up with the molar amount of eugenol.

[0060] Comparative Example 3 As a comparative example of the present invention, this composite epoxy resin film differs from Example 1 in that it uses nano-silica instead of modified nano-silica.

[0061] Comparative Example 4 As a comparative example of the present invention, this composite epoxy resin film differs from Example 1 in that it does not contain carbon fiber.

[0062] Experimental methods I. Sample to be tested The composite epoxy resin films prepared in Examples 1-8 and Comparative Examples 1-4 were prepared and tested according to the required specifications. Bisphenol A epoxy resin was used as a control.

[0063] II. Mechanical Performance Testing The impact strength of the cantilever beam was tested using the XJUD-5.5 cantilever beam impact testing machine, with the sample size being 80mm × 10mm × 4mm and the notch being 2mm, in accordance with GB / 1943-2007.

[0064] III. Dielectric Properties Using a precision impedance analyzer, model Agilent 4294A, at 25°C, at 10 4 ~10 7 Dielectric properties are measured within a frequency range of Hz.

[0065] The mechanical and dielectric properties of Examples 1 to 8 and Comparative Examples 1 to 4 are shown in Table 1.

[0066] Table 1 Dielectric properties of radiation-resistant composite epoxy resin films

[0067] As shown in Table 1, compared with the comparative sample, the above-mentioned radiation-resistant composite epoxy resin film, through double modification of the bisphenol A epoxy resin matrix and the addition of carbon fiber and modified nano-silica filler, improves the dielectric and mechanical properties of the radiation-resistant composite epoxy resin film, has a lower dielectric constant and dielectric loss, and absorbs less electrical energy under the action of alternating electric field. It can be used as an insulating material for microwave communication and exhibits higher electromagnetic wave transparency.

[0068] In Comparative Example 1, no eugenol was added during the preparation of the modified epoxy resin. Compared with Example 1, the prepared sample showed a decrease in impact strength and an increase in dielectric constant and dielectric loss. This indicates that the introduction of eugenol is necessary and can improve the dielectric and mechanical properties of the sample.

[0069] In Comparative Example 2, no 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide was added during the preparation of the modified epoxy resin. Compared with Example 1, the prepared sample showed a decrease in impact strength and an increase in dielectric constant and dielectric loss. This indicates that the introduction of 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide is necessary to improve the dielectric and mechanical properties of the sample.

[0070] Comparative Example 3 used nano-silica. Compared with Example 1, the prepared sample had a lower impact strength and a higher dielectric constant and dielectric loss, which indicates that modified nano-silica can improve the dielectric and mechanical properties of the sample.

[0071] Comparative Example 4, without the addition of carbon fiber, showed a decrease in impact strength and an increase in dielectric constant and dielectric loss compared to Example 1. This indicates that modified nano-silica can improve the dielectric and mechanical properties of the sample.

[0072] IV. Radiation Resistance Test Each laser power density is 3.54 kW / cm², with a power output of 1000 W. 2 The laser was used to irradiate the central area of ​​the gauge length of the sample, covering the surface of the radiation-resistant composite epoxy resin film. The irradiation time was set to 20s, 60s, and 5 minutes. After irradiation, the impact strength and dielectric properties of the sample were tested under different irradiation time conditions.

[0073] The samples to be tested were the products of Example 1, Comparative Examples 1 to 4, and epoxy resin was used as a control.

[0074] Table 2 Results of Radiation Resistance Tests

[0075] As shown in Table 2, the mechanical properties of the composite epoxy resin films of Comparative Examples 1 to 4 decreased after laser irradiation, and the dielectric constant and dielectric loss increased significantly. However, the radiation-resistant composite epoxy resin film of Example 1 basically maintained its original mechanical and dielectric properties after laser irradiation. This indicates that the radiation-resistant composite epoxy resin film of the present invention improves the radiation resistance of the material by doubly modifying the bisphenol A epoxy resin matrix and adding carbon fiber and modified nano-silica filler.

[0076] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, it is intended to include any modifications and variations that fall within the scope of the claims and their equivalents.

Claims

1. A radiation-resistant composite epoxy resin film, characterized in that, It is formed by curing a modified epoxy resin matrix, carbon fiber, modified nano-silica, and a curing agent; wherein the mass proportion of carbon fiber in the composite epoxy resin film is 0.5%~5%, the mass proportion of modified nano-silica in the composite epoxy resin film is 1%~8%, and the balance is curing agent and modified epoxy resin matrix, and the mass ratio of curing agent to modified epoxy resin matrix is ​​5~8:10, totaling 100%; The preparation method of the modified epoxy resin matrix includes the following steps: In an inert gas atmosphere and in an organic solvent, bisphenol A type epoxy resin, 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide and eugenol were used as raw materials, and addition and substitution reactions were carried out under the catalysis of triphenylphosphine to prepare modified epoxy resin. The preparation method of modified nano-silica includes the following steps: A mixed dispersion system of nano-silica and oleic acid-based imidazoline quaternary ammonium salt was prepared using water as a dispersant; the mixed dispersion system was kept at 75℃~85℃ to prepare modified nano-silica. The chemical structure of oleic acid-based imidazoline quaternary ammonium salt is as follows: 。 2. The radiation-resistant composite epoxy resin film according to claim 1, characterized in that, The mass ratio of nano-silica to oleic acid-based imidazoline quaternary ammonium salt is 2:0.8~1.

5.

3. The radiation-resistant composite epoxy resin film according to claim 1, characterized in that, The mass ratio of carbon fiber in the composite epoxy resin film is 1%~3%, and the mass ratio of modified nano-silica in the composite epoxy resin film is 2.5%~6%.

4. The radiation-resistant composite epoxy resin film according to claim 1, characterized in that, The mass ratio of bisphenol A epoxy resin to 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide is 100:25~30, the molar ratio of 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide to eugenol is 1~4:1~4, and the amount of triphenylphosphine is 0.8%~1.2% of the mass of bisphenol A epoxy resin.

5. The radiation-resistant composite epoxy resin film according to claim 1, characterized in that, First, 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide and eugenol were added to an organic solvent containing bisphenol A epoxy resin and mixed at 140℃~160℃. Then, triphenylphosphine was added at 185℃~195℃ and kept at that temperature for 2.5h~3.5h.

6. The radiation-resistant composite epoxy resin film according to claim 1, characterized in that, The organic solvent is dichloromethane.

7. The radiation-resistant composite epoxy resin film according to claim 1, characterized in that, The curing agent is 4,4'-diaminodiphenylmethane, and the length of the carbon fiber does not exceed 3 mm.

8. The method for preparing the radiation-resistant composite epoxy resin film according to claim 1, characterized in that, Includes the following steps: After mixing the modified epoxy resin matrix, modified nano-silica and carbon fiber in a certain weight ratio, a curing agent is added and mixed evenly to obtain a mixture. After degassing the mixture in a vacuum environment at 85℃~90℃, the temperature is raised to 98℃~105℃ and cured for 2~5 hours to obtain a radiation-resistant composite epoxy resin film. The carbon fiber accounts for 0.5% to 5% of the mass of the composite epoxy resin film, the modified nano silica accounts for 1% to 8% of the mass of the composite epoxy resin film, and the remainder is curing agent and modified epoxy resin matrix. The mass ratio of curing agent to modified epoxy resin matrix is ​​5 to 8:10, totaling 100%. The preparation method of the modified epoxy resin matrix includes the following steps: In an inert gas atmosphere and in an organic solvent, bisphenol A type epoxy resin, 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide and eugenol were used as raw materials, and addition and substitution reactions were carried out under the catalysis of triphenylphosphine to prepare modified epoxy resin. The preparation method of modified nano-silica includes the following steps: A mixed dispersion system of nano-silica and oleic acid-based imidazoline quaternary ammonium salt was prepared using water as a dispersant; the mixed dispersion system was kept at 75℃~85℃ to prepare modified nano-silica. The chemical structure of oleic acid-based imidazoline quaternary ammonium salt is as follows: 。

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