Preparation method of high-pressure-resistant high-heat-resistant low-dielectric phenolic epoxy resin

Abstract

The application discloses a preparation method of high-pressure-resistant high-heat-resistant low-dielectric phenolic epoxy resin, and belongs to the field of high polymer resin material preparation, and specifically comprises the following steps: adding a fused ring silicon-phosphorus synergistic rigid phenolic copolymer matrix, epoxy chloropropane and tetrabutylammonium bromide into a reaction kettle to generate ring-opening etherification and ring-closing desalination reaction, and obtaining a functional phenolic epoxy resin; through the synergistic effect between the prepared fused ring silicon-phosphorus synergistic rigid phenolic copolymer matrix and the silicon-based conjugated boron nitride functional powder, the high-pressure-resistant high-heat-resistant low-dielectric phenolic epoxy resin is further optimized in the high-pressure-resistant performance, the high-temperature-resistant performance, the low-dielectric property and the toughness.

Description

Technical Field

[0001] This invention relates to the field of polymer resin material preparation, specifically to a method for preparing a high-pressure resistant, high-heat resistant, low-dielectric phenolic epoxy resin. Background Technology

[0002] Phenolic epoxy resin, with its high crosslinking density, excellent insulation and thermal stability, is widely used in power equipment, electronic packaging, high-voltage insulation components and other fields. It is one of the core materials of high-end electrical insulation systems. With the rapid development of industries such as ultra-high voltage power transmission, new energy power control, and high-frequency electronic devices, the working environment is gradually becoming more demanding, with strong electric fields, wide temperature ranges and long-term continuous operation. The industry is putting forward more stringent requirements for the comprehensive performance of phenolic epoxy resin.

[0003] While conventional phenolic epoxy resins possess basic performance characteristics, there are still areas for improvement. From a molecular structure perspective, traditional phenolic resins have a high proportion of polar groups, resulting in significant molecular polarization. Under high-voltage electric fields, this can easily lead to charge accumulation and migration, limiting the material's breakdown resistance and making its dielectric properties unsuitable for high-frequency, high-voltage applications. Furthermore, the rigid and simple molecular skeleton of conventional resins leads to increased molecular chain movement in high-temperature environments, limiting their thermal stability and making them unable to withstand long-term high-temperature thermal shock. In addition, traditional phenolic epoxy resins generally have inherent brittleness, making them prone to cracking under external forces. This not only reduces the material's lifespan but also allows cracks to further create conductive defects, deteriorating the insulation performance.

[0004] Currently, the simple blending modification method commonly used in the industry easily leads to poor interfacial bonding between inorganic fillers and resin matrix, resulting in voids and interfacial polarization. This makes it impossible to simultaneously meet the multiple requirements of high voltage resistance, low dielectric constant, high heat resistance, and high toughness. In order to adapt to the development needs of the high-end electrical insulation field, the industry urgently needs a technical solution that combines molecular structure design, functional matrix copolymerization, and filler modification to systematically improve the comprehensive performance of materials such as high voltage resistance, heat resistance, low dielectric constant, and toughness while retaining the original advantages of phenolic epoxy resin, thereby making up for the performance shortcomings of existing products. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a high-pressure resistant, high-heat resistant, low-dielectric phenolic epoxy resin, mainly addressing the technical problem of how to further improve the high-pressure resistance, high-temperature resistance, low dielectric properties, and toughness of phenolic epoxy resin.

[0006] The objective of this invention can be achieved through the following technical solution: a method for preparing a high-pressure resistant, high-heat resistant, low-dielectric phenolic epoxy resin, comprising the following steps:

[0007] S1. Add the polycyclic siloxane-phosphorus synergistic rigid phenolic copolymer matrix, epichlorohydrin and tetrabutylammonium bromide to the reactor to carry out ring-opening etherification and ring-closing desalting reactions to obtain functional phenolic epoxy resin.

[0008] S2. Under a nitrogen atmosphere, functional phenolic epoxy resin, antioxidant 1010, and defoamer are added to a reaction vessel and melt-blended uniformly at 115-125℃. Then, the temperature is lowered to 105-110℃ and polyetherimide N-methylpyrrolidone solution is added dropwise. After the addition is complete, the mixture is stirred for 5-8 minutes, and the solvent is removed under vacuum at -0.09MPa. Then, the temperature is raised to 115-125℃, and silicon-based conjugated boron nitride functional powder is added and stirred uniformly. Finally, the temperature is cooled to 70-80℃, and methylhexahydrophthalic anhydride and 2-ethyl-4-methylimidazolium are added and stirred to obtain a composite slurry.

[0009] S3. Pour the composite slurry into a mold preheated to 80℃, keep it in an oven at 100℃ for 1-2 hours to cure, then raise the temperature to 150-160℃ for 3-4 hours to crosslink, and finally let it cool naturally to 50℃ in the oven to demold, thus obtaining a high-pressure resistant, high-heat resistant, low-dielectric phenolic epoxy resin.

[0010] Further, in step S2, the ratio of the functional phenolic epoxy resin, antioxidant 1010, defoamer, polyetherimide N-methylpyrrolidone solution, silicon-based conjugated boron nitride functional powder, methylhexahydrophthalic anhydride, and 2-ethyl-4-methylimidazole is 100 parts: 0.2-0.4 parts: 0.2 parts: 23-25 ​​parts: 10 parts: 88 parts: 0.4 parts; the mass fraction of the polyetherimide N-methylpyrrolidone solution is 35%.

[0011] Furthermore, the preparation method of the functional phenolic epoxy resin is as follows: under a nitrogen atmosphere, a polycyclic silicophosphorus synergistic rigid phenolic copolymer matrix, epichlorohydrin and tetrabutylammonium bromide are added to a reaction vessel, heated to 90-100℃ and reacted for 3-4 hours. After the reaction is completed, the mixture is cooled to 65-70℃, and sodium hydroxide aqueous solution is added dropwise. After the addition is completed, the mixture is reacted at 60-70℃ for 1-2 hours. After the reaction is completed, the mixture is allowed to stand and separated. The organic layer is washed with deionized water at 40-50℃ until the washing solution is neutral, and then transferred to a rotary evaporator. The mixture is rotary evaporated at 65-75℃ and -0.09MPa until it turns yellowish-brown to obtain the functional phenolic epoxy resin.

[0012] Furthermore, the ratio of the polycyclic silicophosphorus synergistic rigid phenolic copolymer matrix, epichlorohydrin, tetrabutylammonium bromide and sodium hydroxide aqueous solution is 100g:230g:0.9g:34-37mL, and the mass fraction of the sodium hydroxide aqueous solution is 45%.

[0013] Furthermore, the preparation method of the polycyclic silicophosphorus synergistic rigid phenolic copolymer matrix is ​​as follows: under a nitrogen atmosphere, naphthol, dicyclopentadiene phenol, 2,6-dimethylphenol and oxalic acid are added to a reaction vessel, heated to 50-60℃ and stirred for 10-15 min, then arylsilicophosphorus-phenanthrene synergistic hydroxyl copolymer functional body is added, stirred for 5-10 min, and then formaldehyde aqueous solution is added dropwise. After the addition is complete, the temperature is first raised to 75-80℃ and reacted for 1-2 h, then raised to 80-85℃ and reacted for 2-3 h. After the reaction is completed, the temperature is lowered to 40-50℃, and 3-4 times the volume of deionized water at 40-50℃ is added to the reaction vessel. After stirring for 5-8 min, the mixture is allowed to stand and separated. The organic layer is taken and evaporated in a rotary evaporator at 60-65℃ and -0.09MPa until transparent to obtain the polycyclic silicophosphorus synergistic rigid phenolic copolymer matrix.

[0014] Furthermore, the ratio of naphthol, dicyclopentadienephenol, 2,6-dimethylphenol, oxalic acid, arylsilylphosphine synergistic hydroxyl copolymer and formaldehyde aqueous solution is 70g:20g:10g:0.6-0.8g:14-15g:37-40mL, and the mass fraction of the formaldehyde aqueous solution is 37%.

[0015] Furthermore, the arylsilylphosphine-phenanthrene synergistic hydroxyl copolymer functionalized body is prepared by the following steps:

[0016] A1. Under a nitrogen atmosphere, 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane, diphenylsilanediol and barium hydroxide were added to a reaction vessel and stirred at 80-90℃ for 3-4 hours. After the reaction was completed, the mixture was distilled at 70-80℃ and -0.09MPa for 30-40 minutes to obtain a diphenyl-bridged alicyclic siloxane prepolymer.

[0017] A2. Add the diphenyl-bridged alicyclic siloxane prepolymer and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to a reactor and keep the reaction at 80-90℃ for 3-4 hours. After the reaction is completed, cool down to 70-80℃ and distill at -0.09MPa for 30-40 minutes to obtain the arylsiloxane-phosphaphenanthrene synergistic hydroxyl copolymer functionalized product.

[0018] Further, in step A1, the ratio of 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane, diphenylsilanediol, and barium hydroxide is 94 mL:48-52 mL:0.7 g; in step A2, the ratio of the bisphenyl-bridged alicyclic siloxane prepolymer and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 5 g:3.1-3.3 g.

[0019] Furthermore, the silicon-based conjugated boron nitride functional powder is prepared by the following steps:

[0020] B1. Add hexagonal boron nitride to a reaction vessel containing deionized water and ultrasonically disperse for 40-60 min. Then, add Tris-HCl buffer to adjust the pH to 8.5. Next, add dopamine hydrochloride and continue stirring for 3-4 h. After centrifugation, collect the solid product, wash it 2-3 times with deionized water, transfer it to a vacuum drying oven, and dry it at 80℃ to constant weight to obtain interface-activated aryl conjugated boron nitride powder.

[0021] B2. The interface-activated aryl conjugated boron nitride powder was added to a reaction vessel containing an aqueous ethanol solution and ultrasonically dispersed for 1-2 hours. Acetic acid was added dropwise to adjust the pH to 3.5-4. KH590 was then added, the temperature was raised to 70-80℃, and the mixture was stirred for 5-6 hours. After the reaction was completed, the solid product was centrifuged and washed 2-3 times with anhydrous ethanol. The product was then transferred to a vacuum drying oven and dried at 60℃ to constant weight to obtain silicon-based conjugated boron nitride functional powder.

[0022] Furthermore, in step B1, the ratio of hexagonal boron nitride, deionized water, and dopamine hydrochloride is 1g:40-50mL:0.2g; in step B2, the ratio of interface-activated aryl conjugated boron nitride powder, ethanol aqueous solution, and KH590 is 1g:80-100mL:0.25mL, and the ethanol aqueous solution has a mass fraction of 80%.

[0023] The present invention has the following beneficial effects:

[0024] 1. The arylsilylphosphorylphenanthrene synergistic hydroxyl copolymer functional body of the present invention contains siloxane and phosphorylphenanthrene cyclic structures. The combination of silicon and phosphorus elements with low polarity molecular chains can reduce the molecular dipole moment. After the functional body is covalently connected to the phenolic system, it forms a fused-ring siloxane-phosphoryl synergistic rigid phenolic copolymer matrix. The naphthol fused ring and alkyl substitution structure in the matrix further weaken the molecular polarization effect. The functional phenolic epoxy resin synthesized with this matrix fully inherits the low polarity skeleton and insulating functional groups, reducing charge accumulation and migration at the molecular level. The silicon-based conjugated boron nitride functional powder itself has excellent intrinsic insulation properties. After modification with dopamine and silane, the surface conjugated layer and silicon-oxygen structure can be tightly combined with the resin matrix, eliminating interphase interface voids, conductive defects and interfacial polarization. The materials form a synergistic effect from multiple dimensions such as molecular chains, cross-linking networks and inorganic fillers, effectively improving the material's breakdown resistance, while significantly reducing the relative permittivity, achieving the comprehensive advantages of high voltage resistance and low dielectric constant.

[0025] 2. The Si-O-Si siloxane segments and phosphaphenanthrene cyclic structures in the arylsiloxane-phosphorus-phenanthrene synergistic hydroxyl copolymer of the present invention have high chemical bond energy and high thermal decomposition temperature, possessing excellent heat resistance. After copolymerization and introduction into the phenolic system, they together with naphthol fused rings and dicyclopentadienyl aliphatic rings to construct a fused-ring silicon-phosphorus synergistic rigid phenolic copolymer matrix, forming a high-density, high-stability rigid cross-linked network, which greatly restricts the thermal motion of molecular chains at high temperatures. The functional phenolic epoxy resin derived from this matrix retains all heat-resistant functional units, and the overall molecular skeleton thermal stability is significantly enhanced. The silicon-based conjugated boron nitride functional powder has extremely high thermal stability. When uniformly dispersed in the resin system, it can build a continuous heat-resistant skeleton, hindering heat transfer and delaying the thermal degradation of molecular chains. The intermediates work together layer by layer to comprehensively enhance the heat resistance from the molecular structure, cross-linking system, and inorganic reinforcing phase, allowing the finished product to achieve a higher insulation and heat resistance level.

[0026] 3. The flexible siloxane segments inside the arylsiloxane-phosphorus-phenanthrene synergistic hydroxyl copolymer functional body of the present invention can play a buffering role in the molecular network, alleviating stress concentration caused by external impact. The fused-ring siloxane-phosphorus synergistic rigid phenolic copolymer matrix obtained by copolymerizing it with polyphenol monomers integrates the fused-ring rigid structure and the alicyclic toughening structure, improving the problem of high brittleness of traditional phenolic resins. The functional phenolic epoxy resin continues this rigid-flexible molecular structure, ensuring that the resin body has good toughness. After the silicon-based conjugated boron nitride functional powder is surface activated and silane grafted and modified, the outer organic transition layer can greatly improve the interfacial bonding force between inorganic powder and organic resin. When subjected to external impact, the impact energy can be dissipated through interfacial slip, crack deflection, energy absorption and other means. The intermediates are mutually adapted and synergistically toughened, making up for the mechanical defects of the single resin system and significantly improving the impact toughness of the material. Detailed Implementation

[0027] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] In this application, hexagonal boron nitride is selected from Forsmann Technology (Beijing) Co., Ltd., with a particle size of 1 μm and catalog number 0506001.

[0029] Example 1

[0030] This embodiment provides a method for preparing a high-pressure resistant, high-heat resistant, low-dielectric phenolic epoxy resin, comprising the following steps:

[0031] S1. Preparation of arylsilylphosphine-phenanthrene synergistic hydroxyl copolymer functionalized products

[0032] Under a nitrogen atmosphere, 940 mL of 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane, 480 mL of diphenylsilanediol, and 7 g of barium hydroxide were weighed and added to a reaction vessel. The mixture was stirred at 80 °C for 3 h. After the reaction was completed, the mixture was distilled at 70 °C and -0.09 MPa for 30 min to obtain a diphenyl-bridged alicyclic siloxane prepolymer.

[0033] Weigh out 200g of diphenyl-bridged alicyclic siloxane prepolymer and 124g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and add them to a reaction vessel. Keep the reaction at 80℃ for 3h. After the reaction is completed, cool down to 70℃ and distill at -0.09MPa for 30min to obtain the arylsilphosphaphenanthrene synergistic hydroxyl copolymer functionalized product.

[0034] Reaction mechanism for preparing arylsilylphosphine-phenanthrene synergistic hydroxyl copolymers:

[0035] Under barium hydroxide weak base catalysis and hydrothermal conditions, the silanol of diphenylsilanediol undergoes a methanol-demethylsiloxane condensation reaction with the methoxy group of 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane, forming Si-O-Si bonds to construct a linear siloxane prepolymer with diphenyl as the bridging unit and alicyclic epoxycyclohexyl groups attached to both sides. The byproduct methanol is removed by low-temperature negative pressure distillation to obtain a diphenyl-bridged alicyclic siloxane prepolymer. Subsequently, the alicyclic epoxy ternary bonds at both ends of the prepolymer molecule are... The cyclooxygen ring undergoes nucleophilic ring-opening addition with the active pH bond of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), resulting in the strained cleavage of the epoxy ring and the generation of secondary hydroxyl groups. The phosphaphenanthrene structure of DOPO is covalently grafted onto the cyclohexane side chain, releasing small molecules. Finally, trace amounts of free DOPO and small molecules are removed by negative pressure distillation to obtain an arylsiloxane-phosphaphenanthrene synergistic hydroxyl copolymer functionalized with a flexible phenylsiloxane backbone, hydroxyl crosslinking sites, and a phosphaphenanthrene flame-retardant structure.

[0036] S2. Preparation of a polycyclic silicon-phosphorus synergistic rigid phenolic copolymer matrix

[0037] Under a nitrogen atmosphere, 700g of naphthol, 200g of dicyclopentadiene phenol, 100g of 2,6-dimethylphenol, and 6g of oxalic acid were weighed and added to a reaction vessel. The mixture was heated to 50°C and stirred for 10 minutes. Then, 140g of arylsilylphosphine-phenanthrene synergistic hydroxyl copolymer was added and stirred for 5 minutes. Next, 370mL of 37wt% formaldehyde aqueous solution was added dropwise over a period of 1.5 hours. After the addition was complete, the temperature was raised to 75°C and reacted for 1 hour, then raised to 80°C and reacted for 2 hours. After the reaction was completed, the temperature was lowered to 40°C, and 3 volumes of 40°C deionized water were added to the reaction vessel. The mixture was stirred for 5 minutes and allowed to stand for separation. The organic layer was taken and evaporated to transparency in a rotary evaporator at 60°C and -0.09MPa to obtain a polycyclic silylphosphine-synergistic rigid phenolic copolymer matrix.

[0038] Reaction mechanism for preparing fused-ring silicon-phosphorus synergistic rigid phenolic copolymer matrix:

[0039] Under nitrogen protection, oxalic acid dissociates upon heating, releasing protons to form a mild, weakly acidic catalytic system. In this system, protons activate an aqueous formaldehyde solution to generate highly active hydroxymethyl carbocations. These carbocations then undergo electrophilic substitution reactions with the fused rings of naphthol, the alicyclic aromatic rings of dicyclopentadienephenol, and the sterically hindered aromatic rings of 2,6-dimethylphenol, simultaneously generating hydroxymethylated naphthol, hydroxymethylated dicyclopentadienephenol, and hydroxymethylated 2,6-dimethylphenol multi-component intermediates. Under heating, the homogeneous prepolymerization and chain extension of the low-sterically hindered active phenols are first completed. Subsequently, the multi-component hydroxymethylphenol intermediates undergo continuous dehydration condensation to form methylene bridges, collectively... A linear multi-component phenolic main chain was constructed. Simultaneously, the secondary hydroxyl groups carried by the phenolic side chain hydroxyl copolymer functional group and the arylsilylphosphine synergistic hydroxyl group in the system underwent an acid-catalyzed intermolecular dehydration etherification reaction to stabilize the COC ether bond and covalently integrate the flexible siloxane chain segment and the rigid phosphine functional structure into the multi-component phenolic linear copolymer backbone. After the reaction, the system was washed and rotary evaporated to remove residual water and trace amounts of low-molecular-weight volatiles, finally yielding a fused-ring silicon-phosphorus synergistic rigid phenolic copolymer matrix rich in active phenolic hydroxyl groups, possessing fused ring rigidity, alicyclic toughness, low polarity hydrophobicity of methyl groups, and synergistic function of phosphorus and silicon.

[0040] S3. Preparation of functional phenolic epoxy resin

[0041] Under a nitrogen atmosphere, 200g of polycyclic silicophosphorus synergistic rigid phenolic copolymer matrix, 460g of epichlorohydrin and 1.8g of tetrabutylammonium bromide were weighed and added to a reaction vessel. The mixture was heated to 90℃ and reacted for 3 hours. After the reaction was completed, the mixture was cooled to 65℃, and 68mL of 45wt% sodium hydroxide aqueous solution was added dropwise. After the addition was completed, the mixture was reacted at 60℃ for 1 hour. After the reaction was completed, the mixture was allowed to stand and separated. The organic layer was washed with deionized water at 40℃ until the washing solution was neutral. The solution was then transferred to a rotary evaporator and rotary evaporated at 65℃ and -0.09MPa until it turned yellowish-brown, thus obtaining the functional phenolic epoxy resin.

[0042] Reaction mechanism for preparing functional phenolic epoxy resins:

[0043] Under the catalysis of tetrabutylammonium bromide phase transfer, the abundant active phenolic hydroxyl groups on the surface of the fused-ring silicon-phosphorus synergistic rigid phenolic copolymer matrix undergo a highly efficient epoxy ring-opening etherification reaction with excess epichlorohydrin under heating conditions, generating a copolymer intermediate with a chlorohydrin side chain. Subsequently, an aqueous sodium hydroxide solution is added to the system to remove hydrogen chloride from the intermediate structure through a neutralization reaction, promoting an intramolecular ring-closure reaction of the chlorohydrin structure and regenerating an epoxy ternary active ring. The reaction system is then subjected to static separation of the organic phase, followed by washing and rotary evaporation to remove excess epichlorohydrin and trace small volatile components. Finally, a functional phenolic epoxy resin is obtained that simultaneously possesses a naphthalene fused-ring high heat-resistant rigid structure, a dicyclopentadiene alicyclic toughening structure, a 2,6-dimethylphenol low polarity hydrophobic unit, a siloxane low water absorption flexible segment, phosphorus-phenanthroline flame-retardant and smoke-suppressing functional groups, and high-purity epoxy curing active sites.

[0044] S4. Preparation of silicon-based conjugated boron nitride functional powder

[0045] Weigh 20g of hexagonal boron nitride and add it to a reaction vessel containing 800mL of deionized water. Disperse the mixture by sonication for 40min. Then, add Tris-HCl buffer to adjust the pH to 8.5. Next, add 4g of dopamine hydrochloride and continue stirring for 3h. After centrifugation, collect the solid product, wash it twice with deionized water, transfer it to a vacuum drying oven, and dry it at 80℃ to constant weight to obtain interface-activated aryl conjugated boron nitride powder.

[0046] Weigh 20g of interface-activated aryl conjugated boron nitride powder and add it to a reaction vessel containing 1600mL of ethanol (80% by mass) aqueous solution. Disperse the mixture ultrasonically for 1h, and add acetic acid dropwise to adjust the pH to 3.5. Then add 5mL of KH590, heat to 70℃, and stir for 5h. After the reaction is complete, centrifuge to separate the solid product, wash it twice with anhydrous ethanol, transfer it to a vacuum drying oven, and dry it at 60℃ to constant weight to obtain silicon-based conjugated boron nitride functional powder.

[0047] Reaction mechanism for preparing silicon-based conjugated boron nitride functional powders:

[0048] In a weakly alkaline environment constructed with Tris-HCl buffer, dopamine hydrochloride undergoes an oxidative self-polymerization reaction, generating a polydopamine conjugated film rich in hydroxyl and amino groups on the surface of dispersed boron nitride sheets through hydrogen bonding. After washing with water and high-temperature vacuum drying, an interface-activated aryl conjugated boron nitride powder is obtained. In a weakly acidic environment regulated by acetic acid, the methoxy group of KH590 is fully hydrolyzed to generate active silanol groups. The silanol groups undergo dehydration condensation with the active hydroxyl and amino groups of polydopamine on the powder surface to form covalent bonds, linking mercaptosilane molecules to the outside of the conjugated organic layer. The reaction product is washed with ethanol to remove free silane impurities, and after drying to remove the solvent, a silicon-based conjugated boron nitride functional powder is obtained, which combines an inorganic thermally conductive and insulating substrate, an aryl conjugated transition layer, and a mercaptosilane-compatible outer layer.

[0049] S5. Preparation of composite slurry

[0050] Under a nitrogen atmosphere, 100 parts by weight of functional phenolic epoxy resin, 0.2 parts by weight of antioxidant 1010 and 0.2 parts by weight of defoamer were weighed and added to a reaction vessel. After melting and mixing evenly at 115°C, the temperature was lowered to 105°C and 23 parts by weight of 35 wt% polyetherimide N-methylpyrrolidone solution were added dropwise. After the addition was completed, the mixture was mixed for 5 min and the solvent was removed under vacuum at -0.09 MPa. Then the temperature was raised to 115°C and 10 parts by weight of silicon-based conjugated boron nitride functional powder were added and mixed evenly. Finally, the temperature was cooled to 70°C and 88 parts by weight of methylhexahydrophthalic anhydride and 0.4 parts by weight of 2-ethyl-4-methylimidazolium were added and mixed to obtain a composite slurry.

[0051] S6. Prepare a high-voltage resistant, high-heat resistant, low-dielectric phenolic epoxy resin.

[0052] Weighing: Pour the composite slurry into a mold preheated to 80℃, keep it in an oven at 100℃ for 1 hour to cure, then raise the temperature to 150℃ and keep it at 150℃ for 3 hours to crosslink, and finally let it cool naturally to 50℃ in the oven to demold, thus obtaining a high-pressure resistant, high-heat resistant, low-dielectric phenolic epoxy resin.

[0053] Example 2

[0054] This embodiment provides a method for preparing a high-pressure resistant, high-heat resistant, low-dielectric phenolic epoxy resin, comprising the following steps:

[0055] S1. Preparation of arylsilylphosphine-phenanthrene synergistic hydroxyl copolymer functionalized products

[0056] Under a nitrogen atmosphere, 940 mL of 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane, 500 mL of diphenylsilanediol, and 7 g of barium hydroxide were weighed and added to a reaction vessel. The mixture was stirred at 85 °C for 3.5 h. After the reaction was completed, the mixture was distilled at 75 °C and -0.09 MPa for 35 min to obtain a diphenyl-bridged alicyclic siloxane prepolymer.

[0057] Weigh out 200g of diphenyl-bridged alicyclic siloxane prepolymer and 138g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and add them to a reaction vessel. Keep the reaction at 85℃ for 3.5h. After the reaction is completed, cool down to 75℃ and distill at -0.09MPa for 35min to obtain the arylsilphosphaphenanthrene synergistic hydroxyl copolymer functionalized product.

[0058] S2. Preparation of a polycyclic silicon-phosphorus synergistic rigid phenolic copolymer matrix

[0059] Under a nitrogen atmosphere, 700g of naphthol, 200g of dicyclopentadiene phenol, 100g of 2,6-dimethylphenol, and 7g of oxalic acid were weighed and added to a reaction vessel. The mixture was heated to 55°C and stirred for 12 minutes. Then, 145g of arylsilylphosphine-phenanthrene synergistic hydroxyl copolymer was added and stirred for 8 minutes. Next, 385mL of 37wt% formaldehyde aqueous solution was added dropwise over a period of 1.75 hours. After the addition was complete, the temperature was raised to 75°C and reacted for 1.5 hours, then raised to 82°C and reacted for 2.5 hours. After the reaction was completed, the temperature was lowered to 45°C, and 3 volumes of 45°C deionized water were added to the reaction vessel. The mixture was stirred for 6 minutes and allowed to stand for separation. The organic layer was taken and evaporated to transparency in a rotary evaporator at 62°C and -0.09MPa to obtain a polycyclic silylphosphine-synergistic rigid phenolic copolymer matrix.

[0060] S3. Preparation of functional phenolic epoxy resin

[0061] Under a nitrogen atmosphere, 200g of polycyclic silicophosphorus synergistic rigid phenolic copolymer matrix, 460g of epichlorohydrin and 1.8g of tetrabutylammonium bromide were weighed and added to a reaction vessel. The mixture was heated to 95℃ and reacted for 3.5h. After the reaction was completed, the mixture was cooled to 67℃, and 71mL of 45wt% sodium hydroxide aqueous solution was added dropwise. After the addition was completed, the mixture was reacted at 65℃ for 1.5h. After the reaction was completed, the mixture was allowed to stand and separated. The organic layer was washed with deionized water at 45℃ until the washing solution was neutral. The solution was then transferred to a rotary evaporator and evaporated at 70℃ and -0.09MPa until it turned yellowish-brown, thus obtaining functional phenolic epoxy resin.

[0062] S4. Preparation of silicon-based conjugated boron nitride functional powder

[0063] Weigh 20g of hexagonal boron nitride and add it to a reaction vessel containing 900mL of deionized water. Disperse the mixture by sonication for 50min. Then, add Tris-HCl buffer to adjust the pH to 8.5. Next, add 4g of dopamine hydrochloride and continue stirring for 3.5h. After centrifugation, collect the solid product, wash it twice with deionized water, transfer it to a vacuum drying oven, and dry it at 80℃ to constant weight to obtain interface-activated aryl conjugated boron nitride powder.

[0064] Weigh 20g of interface-activated aryl conjugated boron nitride powder and add it to a reaction vessel containing 1800mL of ethanol (80% by mass) aqueous solution. Disperse the mixture ultrasonically for 1.5h, and adjust the pH to 3.8 by adding acetic acid dropwise. Then add 5mL of KH590, heat to 75℃, and stir for 5.5h. After the reaction is complete, centrifuge to separate the solid product, wash it twice with anhydrous ethanol, transfer it to a vacuum drying oven, and dry it at 60℃ to constant weight to obtain silicon-based conjugated boron nitride functional powder.

[0065] S5. Preparation of composite slurry

[0066] Under a nitrogen atmosphere, 100 parts by weight of functional phenolic epoxy resin, 0.3 parts by weight of antioxidant 1010 and 0.2 parts by weight of defoamer were weighed and added to a reaction vessel. After melting and mixing evenly at 120°C, the temperature was lowered to 105°C and 24 parts by weight of 35 wt% polyetherimide N-methylpyrrolidone solution were added dropwise. After the addition was completed, the mixture was mixed for 6 min and the solvent was removed under vacuum at -0.09 MPa. Then the temperature was raised to 120°C and 10 parts by weight of silicon-based conjugated boron nitride functional powder were added and mixed evenly. Finally, the temperature was cooled to 75°C and 88 parts by weight of methylhexahydrophthalic anhydride and 0.4 parts by weight of 2-ethyl-4-methylimidazolium were added and mixed to obtain a composite slurry.

[0067] S6. Prepare a high-voltage resistant, high-heat resistant, low-dielectric phenolic epoxy resin.

[0068] Weighing: Pour the composite slurry into a mold preheated to 80℃, keep it in an oven at 100℃ for 1.5h for curing, then raise the temperature to 155℃ for crosslinking for 3.5h, and finally let it cool naturally to 50℃ in the oven to demold, thus obtaining a high-pressure resistant, high-heat resistant, low-dielectric phenolic epoxy resin.

[0069] Example 3

[0070] This embodiment provides a method for preparing a high-pressure resistant, high-heat resistant, low-dielectric phenolic epoxy resin, comprising the following steps:

[0071] S1. Preparation of arylsilylphosphine-phenanthrene synergistic hydroxyl copolymer functionalized products

[0072] Under a nitrogen atmosphere, 940 mL of 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane, 520 mL of diphenylsilanediol, and 7 g of barium hydroxide were weighed and added to a reaction vessel. The mixture was stirred at 90 °C for 4 h. After the reaction was completed, the mixture was distilled at 80 °C and -0.09 MPa for 40 min to obtain a diphenyl-bridged alicyclic siloxane prepolymer.

[0073] Weigh out 200g of diphenyl-bridged alicyclic siloxane prepolymer and 152g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and add them to a reaction vessel. Keep the reaction at 90℃ for 4h. After the reaction is completed, cool down to 80℃ and distill at -0.09MPa for 40min to obtain the arylsilphosphaphenanthrene synergistic hydroxyl copolymer.

[0074] S2. Preparation of a polycyclic silicon-phosphorus synergistic rigid phenolic copolymer matrix

[0075] Under a nitrogen atmosphere, 700g of naphthol, 200g of dicyclopentadiene phenol, 100g of 2,6-dimethylphenol, and 8g of oxalic acid were weighed and added to a reaction vessel. The mixture was heated to 60℃ and stirred for 15 minutes. Then, 150g of arylsilylphosphine-phenanthrene synergistic hydroxyl copolymer was added and stirred for 10 minutes. Next, 400mL of 37wt% formaldehyde aqueous solution was added dropwise over a period of 2 hours. After the addition was complete, the temperature was raised to 80℃ and reacted for 2 hours, then raised to 85℃ and reacted for 3 hours. After the reaction was completed, the temperature was lowered to 50℃, and 4 volumes of 50℃ deionized water were added to the reaction vessel. The mixture was stirred for 8 minutes and allowed to stand for separation. The organic layer was taken and evaporated in a rotary evaporator at 65℃ and -0.09MPa until transparent, yielding a polycyclic silylphosphine-synergistic rigid phenolic copolymer matrix.

[0076] S3. Preparation of functional phenolic epoxy resin

[0077] Under a nitrogen atmosphere, 200g of polycyclic silicophosphorus synergistic rigid phenolic copolymer matrix, 460g of epichlorohydrin and 1.8g of tetrabutylammonium bromide were weighed and added to a reaction vessel. The mixture was heated to 100℃ and reacted for 4 hours. After the reaction was completed, the mixture was cooled to 70℃, and 74mL of 45wt% sodium hydroxide aqueous solution was added dropwise. After the addition was completed, the mixture was reacted at 70℃ for 2 hours. After the reaction was completed, the mixture was allowed to stand and separated. The organic layer was washed with deionized water at 50℃ until the washing solution was neutral. The solution was then transferred to a rotary evaporator and rotary evaporated at 75℃ and -0.09MPa until it turned yellowish-brown, thus obtaining the functional phenolic epoxy resin.

[0078] S4. Preparation of silicon-based conjugated boron nitride functional powder

[0079] Weigh 20g of hexagonal boron nitride and add it to a reaction vessel containing 1000mL of deionized water. Disperse the mixture by sonication for 60min. Then, add Tris-HCl buffer to adjust the pH to 8.5. Next, add 4g of dopamine hydrochloride and continue stirring for 4h. After centrifugation, collect the solid product, wash it three times with deionized water, transfer it to a vacuum drying oven, and dry it at 80℃ to constant weight to obtain interface-activated aryl conjugated boron nitride powder.

[0080] Weigh 20g of interface-activated aryl conjugated boron nitride powder and add it to a reaction vessel containing 2000mL of ethanol (80% by mass) aqueous solution. Disperse the mixture ultrasonically for 2h, and add acetic acid dropwise to adjust the pH to 4. Then add 5mL of KH590, heat to 80℃, and stir for 6h. After the reaction is complete, centrifuge to separate the solid product, wash it three times with anhydrous ethanol, transfer it to a vacuum drying oven, and dry it at 60℃ to constant weight to obtain silicon-based conjugated boron nitride functional powder.

[0081] S5. Preparation of composite slurry

[0082] Under a nitrogen atmosphere, 100 parts by weight of functional phenolic epoxy resin, 0.4 parts by weight of antioxidant 1010 and 0.2 parts by weight of defoamer were weighed and added to a reaction vessel. After melting and mixing evenly at 125°C, the temperature was lowered to 110°C and 25 parts by weight of 35 wt% polyetherimide N-methylpyrrolidone solution were added dropwise. After the addition was completed, the mixture was mixed for 8 min and the solvent was removed under vacuum at -0.09 MPa. Then the temperature was raised to 125°C and 10 parts by weight of silicon-based conjugated boron nitride functional powder were added and mixed evenly. Finally, the temperature was cooled to 80°C and 88 parts by weight of methylhexahydrophthalic anhydride and 0.4 parts by weight of 2-ethyl-4-methylimidazolium were added and mixed to obtain a composite slurry.

[0083] S6. Prepare a high-voltage resistant, high-heat resistant, low-dielectric phenolic epoxy resin.

[0084] Weighing: Pour the composite slurry into a mold preheated to 80℃, keep it in an oven at 100℃ for 2 hours to cure, then raise the temperature to 160℃ and keep it at 160℃ for 4 hours to crosslink, and finally let it cool naturally to 50℃ in the oven to demold, thus obtaining a high-pressure resistant, high-heat resistant, low-dielectric phenolic epoxy resin.

[0085] Comparative Example 1

[0086] The difference between this comparative example and Example 3 is that step S1 is omitted, and the arylsilphosphenanthrene synergistic hydroxyl copolymer is not added in step S2.

[0087] Comparative Example 2

[0088] The difference between this comparative example and Example 3 is that, in step S2, cresol is used instead of naphthol, dicyclopentadienephenol, and 2,6-dimethylphenol to prepare the phenolic matrix.

[0089] Comparative Example 3

[0090] The difference between this comparative example and Example 3 is that step S4 is omitted, and silicon-based conjugated boron nitride functional powder is not added in step S5.

[0091] Performance testing:

[0092] The heat resistance rating of a high-voltage-resistant, high-heat-resistant, low-dielectric phenolic epoxy resin prepared in Examples 1-3 and Comparative Examples 1-3 was determined according to standard GB / T 11021-2014 "Electrical insulation heat resistance and representation method".

[0093] Referring to standard GB / T 1408.1-2016 "Test methods for electrical strength of insulating materials - Part 1: Test at power frequency", the breakdown voltage of a high-voltage resistant, high-heat resistant, low-dielectric phenolic epoxy resin prepared in Examples 1-3 and Comparative Examples 1-3 was determined.

[0094] Referring to standard GB / T 31838.6-2021 "Dielectric and resistive properties of solid insulating materials - Part 6: Dielectric properties (AC method) - Relative permittivity and dielectric loss factor (frequency 0.1Hz~10MHz)", the relative permittivity of a high-voltage resistant, high-heat resistant, low-dielectric phenolic epoxy resin prepared in Examples 1-3 and Comparative Examples 1-3 was determined.

[0095] Referring to standard GB / T 1043.2-2018 "Determination of Impact Properties of Simply Supported Beams of Plastics - Part 2: Instrumented Impact Testing", the unnotched impact strength of simply supported beams made of a high-pressure resistant, high-heat resistant, low-dielectric phenolic epoxy resin prepared in Examples 1-3 and Comparative Examples 1-3 was determined. The specific test results are shown in Table 1 below:

[0096] Table 1 - Performance Test Data of Samples

[0097] Group Project Heat resistance rating (grade) Breakdown voltage (kV) Relative permittivity <![CDATA[Izod impact strength of simply supported beam (kJ / m 2 )]]> Example 1 H 35.4 2.9 13.2 Example 2 H 35.5 2.8 13.3 Example 3 H 35.7 2.7 13.4 Comparative Example 1 B 18.3 3.5 9.1 Comparative Example 2 B 20.6 3.7 7.9 Comparative Example 3 F 22.7 3.3 10.6

[0098] Data Analysis:

[0099] Comparative analysis of the data in Table 1 above shows that the high-voltage resistant, high-heat resistant, low-dielectric phenolic epoxy resin prepared in this invention has a heat resistance rating of H, a breakdown voltage of 35.7 kV, a relative permittivity of 2.7, and a notched impact strength of 13.4 kJ / m² for a simply supported beam. 2 ;

[0100] Comparative Example 1, lacking the addition of arylsiloxane-phosphorus-phenanthrene synergistic hydroxyl copolymer functionalizing agents, lacks core functional structures such as siloxanes and phosphorus-phenanthrenes. The fused-ring siloxane-phosphorus synergistic rigid phenolic copolymer matrix cannot construct a low-polarity, high-stability crosslinking network. The functional phenolic epoxy resin also loses key insulation, heat resistance, and toughening units, leading to a significant decrease in the overall material performance. Its heat resistance grade drops to Class B, the breakdown voltage is only 18.3 kV, and the relative permittivity reaches 3.5. Simultaneously, due to the lack of flexible siloxane segments to buffer stress, its impact resistance deteriorates, with the unnotched impact strength of a simply supported beam being only 9.1 kJ / m. 2 ;

[0101] Comparative Example 2, by replacing naphthol, dicyclopentadiene phenol, and 2,6-dimethylphenol with common cresol, failed to form naphthol fused rings, dicyclopentadiene aliphatic rings, and low-polarity alkyl structures. Even with the addition of arylsilylphosphine-phenanthrene synergistic hydroxyl copolymer functionalists, a stable synergistic system was difficult to form. The polarity of the phenolic matrix molecule increased significantly, and the rigidity and toughness skeleton was lost, resulting in a material heat resistance grade dropping to B, a breakdown voltage of 20.6 kV, and a relative permittivity as high as 3.7. Because the toughening effect brought by the fused and aliphatic rings completely disappeared, the resin brittleness increased significantly, and the unnotched impact strength of the simply supported beam was only 7.9 kJ / m. 2 ;

[0102] Comparative Example 3, lacking the addition of silicon-based conjugated boron nitride functional powder, lost its inorganic filler with high insulation and heat resistance properties. It also lacked the modified powder structure that could optimize interfacial bonding and dissipate impact energy, relying solely on organic functional intermediates. This resulted in an insufficient insulating framework, prominent interfacial polarization issues, a breakdown voltage reduced to 22.7 kV, a relative permittivity of 3.3, the heat-resistant auxiliary effect and crack deflection toughening effect of boron nitride disappearing, the heat resistance grade dropping to F, and the unnotched impact strength of the simply supported beam decreasing to 10.6 kJ / m. 2 .

[0103] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a high-pressure resistant, high-heat resistant, low-dielectric phenolic epoxy resin, characterized in that, Includes the following steps: S1. Add the polycyclic siloxane-phosphorus synergistic rigid phenolic copolymer matrix, epichlorohydrin and tetrabutylammonium bromide to the reactor to carry out ring-opening etherification and ring-closing desalting reactions to obtain functional phenolic epoxy resin. S2. Under a nitrogen atmosphere, a polyetherimide N-methylpyrrolidone solution is added dropwise to a reactor containing a molten blend of functional phenolic epoxy resin, antioxidant 1010, and defoamer. After the addition is complete, the mixture is blended. Then, silicon-based conjugated boron nitride functional powder is added and blended evenly. Finally, methylhexahydrophthalic anhydride and 2-ethyl-4-methylimidazolium are added and blended to obtain a composite slurry. S3. Pour the composite slurry into a preheated mold, cure, crosslink, and mold to obtain a high-pressure resistant, high-heat resistant, low-dielectric phenolic epoxy resin.

2. The method for preparing a high-voltage resistant, high-heat resistant, low-dielectric phenolic epoxy resin according to claim 1, characterized in that, In step S2, the ratio of the functional phenolic epoxy resin, antioxidant 1010, defoamer, polyetherimide N-methylpyrrolidone solution, silicon-based conjugated boron nitride functional powder, methylhexahydrophthalic anhydride, and 2-ethyl-4-methylimidazole is 100 parts: 0.2-0.4 parts: 0.2 parts: 23-25 ​​parts: 10 parts: 88 parts: 0.4 parts; the mass fraction of the polyetherimide N-methylpyrrolidone solution is 35%.

3. The method for preparing a high-voltage resistant, high-heat resistant, low-dielectric phenolic epoxy resin according to claim 1, characterized in that, The preparation method of the functional phenolic epoxy resin is as follows: Under a nitrogen atmosphere, a polycyclic silicophosphorus synergistic rigid phenolic copolymer matrix, epichlorohydrin and tetrabutylammonium bromide are added to a reaction vessel, heated to 90-100℃ and reacted for 3-4 hours. After the reaction is completed, the mixture is cooled to 65-70℃, and sodium hydroxide aqueous solution is added dropwise. After the addition is completed, the mixture is reacted at 60-70℃ for 1-2 hours. After the reaction is completed, the mixture is allowed to stand and separated. The organic layer is washed with deionized water at 40-50℃ until the washing solution is neutral, and then transferred to a rotary evaporator. The mixture is rotary evaporated at 65-75℃ and -0.09MPa until it turns yellowish-brown to obtain the functional phenolic epoxy resin.

4. The method for preparing a high-voltage resistant, high-heat resistant, low-dielectric phenolic epoxy resin according to claim 3, characterized in that, The ratio of the polycyclic silicophosphorus synergistic rigid phenolic copolymer matrix, epichlorohydrin, tetrabutylammonium bromide and sodium hydroxide aqueous solution is 100g:230g:0.9g:34-37mL, and the mass fraction of the sodium hydroxide aqueous solution is 45%.

5. The method for preparing a high-voltage resistant, high-heat resistant, low-dielectric phenolic epoxy resin according to claim 3, characterized in that, The preparation method of the polycyclic silicophosphorus synergistic rigid phenolic copolymer matrix is ​​as follows: Under a nitrogen atmosphere, naphthol, dicyclopentadiene phenol, 2,6-dimethylphenol and oxalic acid are added to a reaction vessel and heated to 50-60℃ and stirred for 10-15 min. Then, arylsilicophosphorus-phenanthrene synergistic hydroxyl copolymer functional body is added and stirred for 5-10 min. Then, formaldehyde aqueous solution is added dropwise. After the addition is complete, the temperature is first raised to 75-80℃ and reacted for 1-2 h, then raised to 80-85℃ and reacted for 2-3 h. After the reaction is completed, the temperature is lowered to 40-50℃, and 3-4 times the volume of deionized water at 40-50℃ is added to the reaction vessel. After stirring for 5-8 min, the mixture is allowed to stand and separated. The organic layer is taken and evaporated in a rotary evaporator at 60-65℃ and -0.09 MPa until transparent to obtain the polycyclic silicophosphorus synergistic rigid phenolic copolymer matrix.

6. The method for preparing a high-voltage resistant, high-heat resistant, low-dielectric phenolic epoxy resin according to claim 5, characterized in that, The ratio of naphthol, dicyclopentadienephenol, 2,6-dimethylphenol, oxalic acid, arylsilylphosphine synergistic hydroxyl copolymer and formaldehyde aqueous solution is 70g:20g:10g:0.6-0.8g:14-15g:37-40mL, and the mass fraction of the formaldehyde aqueous solution is 37%.

7. The method for preparing a high-voltage resistant, high-heat resistant, low-dielectric phenolic epoxy resin according to claim 5, characterized in that, The arylsilylphosphorylphenanthrene-synergistic hydroxyl copolymer functionalized product is prepared by the following steps: A1. Under a nitrogen atmosphere, 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane, diphenylsilanediol and barium hydroxide were added to a reaction vessel and stirred at 80-90℃ for 3-4 hours. After post-treatment, a bisphenyl-bridged alicyclic siloxane prepolymer was obtained. A2. Add the diphenyl-bridged alicyclic siloxane prepolymer and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to a reactor and react at 80-90℃ for 3-4 hours. After post-treatment, the aromatic siloxane phosphaphenanthrene synergistic hydroxyl copolymer functionalized product is obtained.

8. The method for preparing a high-voltage resistant, high-heat resistant, low-dielectric phenolic epoxy resin according to claim 7, characterized in that, In step A1, the ratio of 2-(3,4-epoxycyclohexane)ethyltrimethoxysilane, diphenylsilanediol, and barium hydroxide is 94 mL:48-52 mL:0.7 g; in step A2, the ratio of the bisphenyl-bridged alicyclic siloxane prepolymer and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 5 g:3.1-3.3 g.

9. The method for preparing a high-voltage resistant, high-heat resistant, low-dielectric phenolic epoxy resin according to claim 1, characterized in that, The silicon-based conjugated boron nitride functional powder is prepared by the following steps: B1. Add hexagonal boron nitride to a reaction vessel containing deionized water and ultrasonically disperse for 40-60 min. Then add Tris-HCl buffer to adjust the pH to 8.

5. Next, add dopamine hydrochloride and continue stirring for 3-4 h. After post-processing, obtain interface-activated aryl conjugated boron nitride powder. B2. The interface-activated aryl conjugated boron nitride powder was added to a reaction vessel containing an aqueous ethanol solution and ultrasonically dispersed for 1-2 hours. Acetic acid was added dropwise to adjust the pH to 3.5-4. KH590 was then added, the temperature was raised to 70-80℃, and the mixture was stirred for 5-6 hours. After post-treatment, silicon-based conjugated boron nitride functional powder was obtained.

10. The method for preparing a high-voltage resistant, high-heat resistant, low-dielectric phenolic epoxy resin according to claim 9, characterized in that, In step B1, the ratio of hexagonal boron nitride, deionized water, and dopamine hydrochloride is 1g:40-50mL:0.2g; in step B2, the ratio of interface-activated aryl conjugated boron nitride powder, ethanol aqueous solution, and KH590 is 1g:80-100mL:0.25mL, and the ethanol aqueous solution has a mass fraction of 80%.