Macromolecular insulating resin composite material and preparation method thereof

Abstract

The invention relates to the technical field of concrete, in particular to a polymer insulating resin composite material which comprises the following raw materials in parts by weight: 50-70 parts of epoxy resin, 10-20 parts of a curing agent, 2-8 parts of a first additive, 1-5 parts of a second additive, 5-10 parts of a flame retardant and 0.5-2 parts of a coupling agent. According to the invention, the first additive catalyzes and carbonizes waste paper to form a carbon nanotube loaded zinc oxide structure, by virtue of high conductivity of a conjugated pi bond, a charge conduction network is formed on the surface of the material, static electricity is quickly dissipated, and corona discharge caused by local electric field concentration is avoided; carriers are adsorbed and captured by surface hydroxyl groups, bulk phase conduction is inhibited by combining a physical barrier effect, surface conduction and bulk phase insulation functions are realized, and the problem of early failure caused by electrostatic accumulation of a traditional insulation resin material is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and specifically to a polymer insulating resin composite material and a preparation method thereof. Background Art

[0002] Polymer insulating resin composite materials have the light weight, flexibility and excellent dielectric properties of polymer materials, and at the same time have good mechanical strength, heat resistance and environmental stability. They are widely used in the fields of power equipment, electronic component packaging, aerospace, etc. Such materials have characteristics such as high resistivity, low dielectric loss, and arc resistance, and can effectively isolate current and prevent leakage of electricity. They are one of the key materials in the modern electrical insulation field.

[0003] In the prior art, due to the low polarity of the molecular chain and the lack of free carriers in the insulating resin composite material, the surface resistivity is extremely high, and the charge migration depends on the slow ion hopping conduction mechanism. Under high voltage and friction conditions, the static charges captured on the material surface locally accumulate due to the lack of a continuous conductive path, forming an electric field distortion, and then there are problems such as dendritic discharge caused by electrostatic accumulation and dielectric breakdown causing material failure. Based on this, the present invention provides a polymer insulating resin composite material and a preparation method thereof. Summary of the Invention

[0004] The purpose of the present invention is to provide a polymer insulating resin composite material and a preparation method thereof. The concrete prepared by the present invention not only has good insulating performance, but also has excellent heat conduction ability and anti-partial discharge aging ability.

[0005] To achieve the above purpose, the present invention provides the following technical solutions: A polymer insulating resin composite material, comprising the following raw materials in parts by weight: 50-70 parts of epoxy resin, 10-20 parts of curing agent, 2-8 parts of first additive, 1-5 parts of second additive, 5-10 parts of flame retardant and 0.5-2 parts of coupling agent; The preparation method of the second additive comprises the following steps: Step 1: Dissolve rare earth nitrate in absolute ethanol to prepare a solution with a concentration of 0.1-0.3 mol / L, which is the first solution; Step 2: Dissolve the β-diketone ligand in absolute ethanol to prepare a solution with a concentration of 0.2-0.5 mol / L, which is the second solution; Step 3: Stir the second solution under the conditions of a stirring speed of 200-300 rpm and a temperature of 50-70 °C, and then add the first solution dropwise into the second solution at a dropping rate of 1-2 drops / s to obtain a third solution. Adjust the pH value of the third solution to 6-8 and then continue to stir and react for 2-4 h. After filtration, select the precipitate and wash and dry it to obtain a rare earth complex; Step 4: Mix boron nitride nanosheets with the rare earth complex prepared in Step 3 at a mass ratio of 6:1, stir and react at 60 - 80°C for 4 - 8 h, and obtain the second additive after filtration, washing, and drying.

[0006] Preferably, the epoxy resin can be any one of bisphenol A epoxy resin and bisphenol F epoxy resin.

[0007] Preferably, the curing agent can be any one of ethylenediamine, diethylenetriamine, and m-phenylenediamine.

[0008] Preferably, the flame retardant can be any one of aluminum hydroxide and magnesium hydroxide or an equal amount combination.

[0009] Preferably, the preparation method of the first additive includes the following steps: Step 1: Collect waste newspapers and crush them to a particle size of 1 - 3 mm, add them to a sodium hydroxide solution with a concentration of 0.5 mol / L, stir and process at 70 - 80°C and 200 - 300 rpm, and obtain waste paper materials after removing the filtrate and air drying. Step 2: Immerse the waste paper materials in a ferric nitrate solution with a concentration of 0.1 - 0.3 mol / L, with a solid-liquid ratio of the waste paper materials to the ferric nitrate solution of 1:(12 - 15), perform ultrasonic impregnation for 30 - 40 min, remove the filtrate and then perform drying treatment to obtain the first base material. Step 3: Under a nitrogen atmosphere, heat the first base material at a heating rate of 10°C / min to 700 - 800°C, and obtain the second base material after holding for 1 - 2 h. Step 4: Disperse the second base material in an acetic acid zinc solution with a concentration of 0.05 - 0.1 mol / L, with a solid-liquid ratio of the second base material to the acetic acid zinc solution of 1:(15 - 20), add hexamethylenetetramine, react at 90°C for 5 - 7 h, take the precipitate, wash it to neutrality and then dry it, and anneal the obtained product in an air atmosphere at 400°C for 2 h to obtain the first additive.

[0010] Preferably, in Step 1, the solid-liquid ratio of the waste newspapers to the sodium hydroxide solution is 1:(10 - 12).

[0011] Preferably, in Step 2, the β-diketone ligand can be any one of hexafluoroacetylacetone and acetylacetone, and in Step 3, the molar ratio of the first solution to the second solution is 1:(2 - 3).

[0012] Preferably, the method for preparing boron nitride nanosheets is as follows: after mixing hexagonal boron nitride powder and N-methylpyrrolidone in a mass ratio of 1:(5-10), ultrasonic exfoliation is performed by liquid phase exfoliation method at a power of 200-400 W and a frequency of 40 kHz for 24-48 hours, the resulting mixed solution is centrifuged at 5000-8000 rpm for 30-40 minutes, and the supernatant is dried to obtain boron nitride nanosheets.

[0013] Preferably, the coupling agent can be selected from any one of KH550 and KH560 or an equal combination thereof.

[0014] Preferably, a method for preparing a polymer insulating resin composite material comprises the following steps: S1: Put the epoxy resin into a stirring kettle, heat it to 80-100°C, then add the coupling agent, and stir at a speed of 300-500 rpm for 10-20 minutes; S2: Add the second additive into the stirring tank in S1, and stir at a speed of 500-800 rpm for 30-60 min; S3: adding the first additive into the stirring kettle in S1, and continuing stirring at a speed of 500 to 800 rpm for 30 to 60 minutes to obtain a mixture; S4: Cool the mixture to 40-60°C, add a curing agent and a flame retardant, stir at a speed of 200-400rpm for 10-20min, degas the resulting product under vacuum conditions of ≤-0.09MPa for 10-30min, inject the resulting product into a mold, pre-cure at 80-100°C for 2-4h, then heat to 120-150°C and cure for 4-8h to obtain a polymer insulating resin composite material.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. In the present invention, a first additive is added during the preparation of a polymer insulating resin composite material. The first additive forms a carbon nanotube-loaded zinc oxide structure by catalytic carbonization of waste paper. With the high conductivity of conjugated π bonds, a charge conduction network is formed on the surface of the material, static electricity is quickly dissipated, and corona discharge caused by local electric field concentration is avoided. Zinc oxide, as a wide bandgap semiconductor, is coated with carbon nanotubes in the form of quantum dots, and surface hydroxyl groups are combined to capture carriers. The physical barrier effect is combined to suppress bulk conductivity, thereby achieving surface conductivity and bulk insulation functions, and solving the problem of early failure caused by static electricity accumulation in traditional insulating resin materials.

[0016] 2. In the present invention, a second additive is added during the preparation of the polymer insulating resin composite material. The second additive utilizes the characteristic of rare earth ion electron transition to convert the ultraviolet light energy generated by corona into heat energy and dissipate it, inhibiting the photo-oxygen degradation of the resin. The two-dimensional sheet layer of boron nitride nanosheets constructs a heat conduction path to quickly conduct out the heat of local hot spots. The rare earth complex forms a covalent bond through the condensation of the ligand with the hydroxyl groups on the surface of boron nitride nanosheets, reducing the aggregation of fillers and improving the dispersion uniformity, which can effectively break through the bottleneck that it is difficult to balance anti-aging and thermal management in traditional insulating resin materials. Detailed Embodiment

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. 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 creative efforts shall fall within the protection scope of the present invention. Embodiment

[0018] A polymer insulating resin composite material includes the following raw materials in parts by weight: 50 parts of epoxy resin, 10 parts of curing agent, 2 parts of first additive, 1 part of second additive, 5 parts of flame retardant, and 0.5 part of coupling agent.

[0019] The epoxy resin selects bisphenol A epoxy resin.

[0020] The curing agent selects ethylenediamine.

[0021] The flame retardant selects aluminum hydroxide.

[0022] The preparation method of the first additive includes the following steps: Step 1: Collect waste newspapers and crush them to a particle size of 1 mm, add them to a sodium hydroxide solution with a concentration of 0.5 mol / L, and the solid-liquid ratio of waste newspapers to sodium hydroxide solution is 1:10. Stir at 70 °C and 200 rpm, and obtain waste paper materials after removing the filtrate and air drying. Step 2: Immerse the waste paper materials in a ferric nitrate solution with a concentration of 0.1 mol / L, and the solid-liquid ratio of waste paper materials to ferric nitrate solution is 1:12. After ultrasonic impregnation for 30 min, remove the filtrate and then perform drying treatment to obtain the first base material. Step 3: Under a nitrogen atmosphere, heat the first base material at a heating rate of 10 °C / min to 700 °C, and obtain the second base material after holding for 1 h. Step 4: Disperse the second base material in a 0.05 mol / L zinc acetate solution. The solid-liquid ratio of the second base material to the zinc acetate solution is 1:15. Add hexamethylenetetramine and react at 90 °C for 5 h. Take the precipitate, wash it until neutral, and then dry it. Anneal the obtained product in an air atmosphere at 400 °C for 2 h to obtain the first additive.

[0023] The preparation method of the second additive includes the following steps: Step 1: Dissolve rare earth nitrate in absolute ethanol to prepare a 0.1 mol / L solution, which is the first solution. Step 2: Dissolve the β-diketone ligand in absolute ethanol to prepare a 0.2 mol / L solution, which is the second solution. Step 3: Stir the second solution at a stirring speed of 200 rpm and a temperature of 50 °C, and then add the first solution dropwise to the second solution at a dropping rate of 1 drop / s to obtain a third solution. Adjust the pH value of the third solution to 6 and continue stirring and reacting for 2 h. After filtration, select the precipitate and wash and dry it to obtain a rare earth complex. Step 4: Mix the boron nitride nanosheets and the rare earth complex prepared in Step 3 at a mass ratio of 6:1, stir and react at 60 °C for 4 h, and obtain the second additive after filtration, washing, and drying.

[0024] In Step 2, the β-diketone ligand is selected as hexafluoroacetylacetone. In Step 3, the molar ratio of the first solution to the second solution is 1:2.

[0025] The preparation method of the boron nitride nanosheets is as follows: Mix hexagonal boron nitride powder and N-methylpyrrolidone at a mass ratio of 1:5, and then perform ultrasonic peeling by liquid-phase exfoliation at a power of 200 W and a frequency of 40 kHz for 24 h. Then, centrifuge the obtained mixture at 5000 rpm for 30 min, and take the supernatant and dry it to obtain boron nitride nanosheets.

[0026] The coupling agent is selected as KH550.

[0027] A preparation method of a polymer insulating resin composite material includes the following steps: S1: Put epoxy resin into a stirring kettle, heat it to 80 °C, and then add a coupling agent and stir at a speed of 300 rpm for 10 min. S2: Add the second additive to the stirring kettle in S1 and stir at a speed of 500 rpm for 30 min. S3: Add the first additive to the stirring kettle in S1 and continue to stir at a speed of 500 rpm for 30 min to obtain a mixture. S4: Cool the mixture to 40°C, add a curing agent and a flame retardant, stir for 10 min at a speed of 200 rpm, defoam the resulting product for 10 min under a vacuum of ≤ -0.09 MPa, then inject the resulting product into a mold, pre-cure at 80°C for 2 h, and then cure at 120°C for 4 h to obtain a polymer insulating resin composite material. Example

[0028] A polymer insulating resin composite material comprises the following raw materials in parts by weight: 70 parts of epoxy resin, 20 parts of curing agent, 8 parts of first additive, 5 parts of second additive, 10 parts of flame retardant, and 2 parts of coupling agent.

[0029] The epoxy resin is selected as bisphenol F type epoxy resin.

[0030] The curing agent is selected as m-phenylenediamine.

[0031] The flame retardant is selected as magnesium hydroxide.

[0032] The preparation method of the first additive comprises the following steps: Step 1: Collect waste newspapers and crush them to a particle size of 3 mm, add them into a sodium hydroxide solution with a concentration of 0.5 mol / L, the solid-liquid ratio of waste newspapers to sodium hydroxide solution is 1:12, stir and process at 80°C and 300 rpm, remove the filtrate and air-dry to obtain waste paper materials; Step 2: Immerse the waste paper materials in a ferric nitrate solution with a concentration of 0.3 mol / L, the solid-liquid ratio of waste paper materials to ferric nitrate solution is 1:15, perform ultrasonic impregnation for 40 min, remove the filtrate and then perform drying treatment to obtain first base materials; Step 3: Under a nitrogen atmosphere, heat the first base materials to 800°C at a heating rate of 10°C / min, hold for 2 h to obtain second base materials; Step 4: Disperse the second base materials in an acetic acid zinc solution with a concentration of 0.1 mol / L, the solid-liquid ratio of the second base materials to the acetic acid zinc solution is 1:20, add hexamethylenetetramine, react at 90°C for 7 h, take the precipitate, wash it to neutral and then dry it, and anneal the resulting product in an air atmosphere at 400°C for 2 h to prepare the first additive.

[0033] The preparation method of the second additive comprises the following steps: Step 1: Dissolve rare earth nitrate in absolute ethanol to prepare a solution with a concentration of 0.3 mol / L, which is the first solution; Step 2: Dissolve β-diketone ligand in absolute ethanol to prepare a solution with a concentration of 0.5 mol / L, which is the second solution; Step 3: Stir the second solution at a stirring speed of 300 rpm and a temperature of 70 °C, and then add the first solution dropwise to the second solution at a dropping rate of 2 drops / s to obtain a third solution. Adjust the pH value of the third solution to 8 and continue stirring for 4 h. After filtration, select the precipitate and wash and dry it to obtain a rare earth complex. Step 4: Mix the boron nitride nanosheets and the rare earth complex prepared in Step 3 in a mass ratio of 6:1, and stir and react at 80 °C for 8 h. After filtration, washing, and drying, a second additive is obtained.

[0034] In Step 2, the β-diketone ligand is selected as acetylacetone. In Step 3, the molar ratio of the first solution to the second solution is 1:3.

[0035] The preparation method of the boron nitride nanosheets is as follows: Mix hexagonal boron nitride powder and N-methylpyrrolidone in a mass ratio of 1:10, and then perform ultrasonic exfoliation by liquid-phase exfoliation method at a power of 400 W and a frequency of 40 kHz for 48 h. Then, centrifuge the obtained mixture at 8000 rpm for 40 min, and take the supernatant and dry it to obtain boron nitride nanosheets.

[0036] The coupling agent is selected as KH560.

[0037] A preparation method of a polymer insulating resin composite material includes the following steps: S1: Put epoxy resin into a stirring kettle, heat it to 100 °C, and then add a coupling agent, and stir at a speed of 500 rpm for 20 min; S2: Add the second additive to the stirring kettle in S1, and stir at a speed of 800 rpm for 60 min; S3: Add the first additive to the stirring kettle in S1, and continue to stir at a speed of 800 rpm for 60 min to obtain a mixture; S4: Cool the mixture to 60 °C, add a curing agent and a flame retardant, and stir at a speed of 400 rpm for 20 min. Debubble the obtained product under a vacuum degree of ≤ -0.09 MPa for 30 min, then inject the obtained product into a mold, pre-cure it at 100 °C for 4 h, and then raise the temperature to 150 °C and cure it for 8 h to obtain a polymer insulating resin composite material. Example

[0038] A polymer insulating resin composite material includes the following raw materials in parts by weight: 60 parts of epoxy resin, 15 parts of curing agent, 5 parts of first additive, 3 parts of second additive, 8 parts of flame retardant, and 1 part of coupling agent.

[0039] The epoxy resin is selected as bisphenol A epoxy resin.

[0040] The curing agent is selected as diethylenetriamine.

[0041] The flame retardants are selected as an equal combination of aluminum hydroxide and magnesium hydroxide.

[0042] The preparation method of the first additive includes the following steps: Step 1: Collect waste newspapers and crush them to a particle size of 2 mm. Add them to a sodium hydroxide solution with a concentration of 0.5 mol / L. The solid-liquid ratio of the waste newspapers to the sodium hydroxide solution is 1:11. Stir and process at 75 °C and 250 rpm. After removing the filtrate and air-drying, waste paper materials are obtained; Step 2: Immerse the waste paper materials in a ferric nitrate solution with a concentration of 0.2 mol / L. The solid-liquid ratio of the waste paper materials to the ferric nitrate solution is 1:13. After ultrasonic impregnation for 35 min, remove the filtrate and then perform drying treatment to obtain the first base material; Step 3: Under a nitrogen atmosphere, heat the first base material at a heating rate of 10 °C / min to 750 °C, and keep it at this temperature for 1.5 h to obtain the second base material; Step 4: Disperse the second base material in a zinc acetate solution with a concentration of 0.08 mol / L. The solid-liquid ratio of the second base material to the zinc acetate solution is 1:18. Add hexamethylenetetramine and react at 90 °C for 6 h. Take the precipitate, wash it until neutral, and then dry it. The obtained product is annealed in an air atmosphere at 400 °C for 2 h to prepare the first additive.

[0043] The preparation method of the second additive includes the following steps: Step 1: Dissolve rare earth nitrate in absolute ethanol to prepare a solution with a concentration of 0.2 mol / L, which is the first solution; Step 2: Dissolve the β-diketone ligand in absolute ethanol to prepare a solution with a concentration of 0.3 mol / L, which is the second solution; Step 3: Stir the second solution at a stirring speed of 250 rpm and a temperature of 60 °C, and then add the first solution dropwise to the second solution at a dropping rate of 1 drop / s to obtain the third solution. Adjust the pH value of the third solution to 7 and continue stirring and reacting for 3 h. After filtration, select the precipitate, wash it, and dry it to prepare the rare earth complex; Step 4: Mix the boron nitride nanosheets with the rare earth complex prepared in Step 3 at a mass ratio of 6:1, and stir and react at 70 °C for 6 h. After filtration, washing, and drying, the second additive is prepared.

[0044] In Step 2, the β-diketone ligand is selected as hexafluoroacetylacetone. In Step 3, the molar ratio of the first solution to the second solution is 1:2.

[0045] The preparation method of boron nitride nanosheets is as follows: hexagonal boron nitride powder and N-methylpyrrolidone are mixed at a mass ratio of 1:8, and then subjected to ultrasonic exfoliation by liquid-phase exfoliation method for 36 h under the conditions of a power of 300 W and a frequency of 40 kHz. The obtained mixture is centrifuged at 6500 rpm for 35 min, and the supernatant is taken and dried to obtain boron nitride nanosheets.

[0046] The coupling agents selected are an equal combination of KH550 and KH560.

[0047] A preparation method of a polymer insulating resin composite material includes the following steps: S1: Put epoxy resin into a stirring kettle, heat it to 90 °C, then add a coupling agent, and stir at a speed of 400 rpm for 15 min; S2: Add the second additive to the stirring kettle in S1, and stir at a speed of 650 rpm for 45 min; S3: Add the first additive to the stirring kettle in S1, and continue to stir at a speed of 650 rpm for 45 min to obtain a mixture; S4: Cool the mixture to 50 °C, add a curing agent and a flame retardant, stir at a speed of 300 rpm for 15 min, defoam the obtained product under a vacuum degree of ≤ -0.09 MPa for 20 min, then inject the obtained product into a mold, pre-cure at 90 °C for 3 h, and then raise the temperature to 135 °C and cure for 6 h to obtain a polymer insulating resin composite material.

[0048] Comparative Example 1. The difference between this comparative example and Example 1 is that: this comparative example does not contain the first additive.

[0049] Comparative Example 2. The difference between this comparative example and Example 1 is that: this comparative example does not contain the second additive.

[0050] Comparative Example 3. The difference between this comparative example and Example 1 is that: this comparative example does not contain the first additive and the second additive.

[0051] Comparative Example 4. The difference between this comparative example and Example 1 is that: in the preparation of the second additive in this comparative example, alumina powder is used to replace boron nitride nanosheets.

[0052] Performance test: The concretes prepared in Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4 are subjected to performance tests, and the obtained test data are recorded in the following table:

[0053] In the performance test, the volume resistivity test adopts the test method in GB / T1410-2006, the thermal conductivity test adopts the test method in GB / T11048-2008, and the corona resistance life test adopts the test method in GB / T16927.1-2011. The volume resistivity, thermal conductivity and corona resistance life of the polymer insulating resin composite materials prepared in Examples 1-3 and Comparative Examples 1-4 are tested in turn, so as to evaluate the insulation performance, thermal conductivity and partial discharge aging resistance of the materials; It can be seen that the overall performance of the polymer insulating resin composite materials prepared in Examples 1-3 is better than that of Comparative Examples 1-4; this shows that: The first additive forms a carbon nanotube-loaded zinc oxide structure by catalytic carbonization of waste paper. With the high conductivity of conjugated π bonds, a charge conduction network is formed on the surface of the material, which quickly dissipates static electricity and avoids corona discharge caused by local electric field concentration. Zinc oxide, as a wide bandgap semiconductor, is coated with carbon nanotubes in the form of quantum dots, and the surface hydroxyl adsorption captures carriers. The physical barrier effect is combined to inhibit bulk conductivity, realize surface conductivity and bulk insulation functions, and solve the problem of early failure caused by static electricity accumulation of traditional insulating resin materials. However, due to the lack of the first additive, comparative examples 1-4 lack static electricity dissipation and insulation enhancement mechanisms, and the corona resistance performance is far inferior to that of examples 1-3, and the problem of static electricity accumulation under high voltage cannot be effectively solved; The second additive utilizes the electronic transition characteristics of rare earth ions to convert the ultraviolet light energy generated by the corona into heat energy dissipation, thereby inhibiting the photo-oxidation degradation of the resin. The two-dimensional layers of the boron nitride nanosheets construct a thermal conduction path to quickly conduct heat from local hot spots. The rare earth complex forms a covalent bond through the condensation of the ligand and the hydroxyl group on the surface of the boron nitride nanosheet, which reduces the agglomeration of the filler and improves the uniformity of dispersion. It can effectively break through the bottleneck of the traditional insulating resin material that is difficult to balance anti-aging and thermal management. However, due to the lack of the second additive, the corona resistance and thermal conductivity of comparative examples 1-4 are obviously insufficient.

[0054] By comparing and analyzing the relevant data in the table, it can be seen that the polymer insulating resin composite material prepared by the present invention not only has good insulation performance, but also has excellent thermal conductivity and resistance to partial discharge aging. This shows that the polymer insulating resin composite material provided by the present invention has a broader market prospect and is more suitable for promotion.

[0055] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0056] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A polymer insulating resin composite material, characterized in that, It includes the following raw materials in parts by weight: 50-70 parts of epoxy resin, 10-20 parts of curing agent, 2-8 parts of first additive, 1-5 parts of second additive, 5-10 parts of flame retardant, and 0.5-2 parts of coupling agent; The preparation method of the second additive includes the following steps: Step 1: Dissolve rare earth nitrate in absolute ethanol to prepare a solution with a concentration of 0.1-0.3 mol / L, which is the first solution; Step 2: Dissolve β-diketone ligand in absolute ethanol to prepare a solution with a concentration of 0.2-0.5 mol / L, which is the second solution; Step 3: Stir the second solution under the conditions of a stirring speed of 200-300 rpm and a temperature of 50-70 °C, and then add the first solution dropwise to the second solution at a dropping rate of 1-2 drops / s to obtain a third solution. Adjust the pH value of the third solution to 6-8 and then continue stirring and reacting for 2-4 h. After filtration, select the precipitate and wash and dry it to obtain a rare earth complex; Step 4: Mix boron nitride nanosheets with the rare earth complex prepared in Step 3 at a mass ratio of 6:1, stir and react at 60-80 °C for 4-8 h, and obtain the second additive after filtration, washing, and drying.

2. The polymeric insulating resin composite material according to claim 1, characterized in that, The epoxy resin can be any one of bisphenol A epoxy resin and bisphenol F epoxy resin.

3. The polymer insulating resin composite material according to claim 1, characterized in that, The curing agent can be any one of ethylenediamine, diethylenetriamine, and m-phenylenediamine.

4. The polymeric insulating resin composite material according to claim 1, wherein, The flame retardant can be any one of aluminum hydroxide and magnesium hydroxide or an equal combination.

5. The polymer insulating resin composite material according to claim 1, wherein The preparation method of the first additive includes the following steps: Step 1: Collect waste newspapers and crush them to a particle size of 1-3 mm, add them to a sodium hydroxide solution with a concentration of 0.5 mol / L, stir and process at 70-80 °C and 200-300 rpm. After removing the filtrate and air-drying, obtain waste paper materials; Step 2: Immerse the waste paper materials in a ferric nitrate solution with a concentration of 0.1-0.3 mol / L. The solid-liquid ratio of the waste paper materials to the ferric nitrate solution is 1:(12-15). After ultrasonic impregnation for 30-40 min, remove the filtrate and then perform drying treatment to obtain the first base material; Step 3: Under a nitrogen atmosphere, heat the first base material at a heating rate of 10 °C / min to 700-800 °C, and keep it warm for 1-2 h to obtain the second base material; Step 4: Disperse the second base material in a zinc acetate solution with a concentration of 0.05-0.1 mol / L. The solid-liquid ratio of the second base material to the zinc acetate solution is 1:(15-20). Add hexamethylenetetramine and react at 90 °C for 5-7 h. Take the precipitate, wash it to neutrality and then dry it. Anneal the obtained product in an air atmosphere at 400 °C for 2 h to obtain the first additive.

6. The polymer insulating resin composite material according to claim 5, wherein In the above Step 1, the solid-liquid ratio of the waste newspaper to the sodium hydroxide solution is 1:(10-12).

7. The polymeric insulating resin composite material according to claim 1, wherein In the above Step 2, the β-diketone ligand can be any one of hexafluoroacetylacetone and acetylacetone. In the above Step 3, the molar ratio of the first solution to the second solution is 1:(2-3).

8. The polymer insulating resin composite material according to claim 6, characterized in that, The preparation method of the boron nitride nanosheets is as follows: hexagonal boron nitride powder and N-methylpyrrolidone are mixed at a mass ratio of 1:(5-10), and then subjected to ultrasonic exfoliation by the liquid-phase exfoliation method for 24-48 h under the conditions of a power of 200-400 W and a frequency of 40 kHz. After that, the obtained mixed solution is centrifuged at 5000-8000 rpm for 30-40 min, and the supernatant is taken and dried to obtain boron nitride nanosheets.

9. The polymer insulating resin composite material according to claim 1, characterized in that The coupling agent can be any one or an equivalent combination of KH550 and KH560.

10. A method for preparing the polymer insulating resin composite material according to any one of claims 1 to 9, characterized in that, It includes the following steps: S1: Put the epoxy resin into a stirring kettle, heat it to 80-100 °C, and then add the coupling agent, and stir at a speed of 300-500 rpm for 10-20 min; S2: Add the second additive to the stirring kettle in S1, and stir at a speed of 500-800 rpm for 30-60 min; S3: Add the first additive to the stirring kettle in S1, and continue to stir at a speed of 500-800 rpm for 30-60 min to obtain a mixture; S4: Cool the mixture to 40-60 °C, add a curing agent and a flame retardant, stir at a speed of 200-400 rpm for 10-20 min, defoam the obtained product under the condition of a vacuum degree ≤ -0.09 MPa for 10-30 min, then inject the obtained product into a mold, pre-cure it at 80-100 °C for 2-4 h, and then raise the temperature to 120-150 °C and cure it for 4-8 h to obtain a polymer insulating resin composite material.

Images