Corrosion-resistant cross arm and preparation method thereof

Abstract

The invention relates to the field of cross arm hoops, and provides a corrosion-resistant cross arm and a preparation method thereof. The corrosion-resistant cross arm comprises a core layer and an outer layer, wherein the core layer is prepared from the following matrix raw materials in parts by weight: 40 to 50 parts of bisphenol A type epoxy resin, 5 to 10 parts of reactive diluent AGE, 3 to 5 parts of boron nitride micro powder and 50 to 60 parts of methylhexahydrophthalic anhydride; the glass fiber accounts for 60-70 wt% of the matrix raw material; the outer layer is prepared from the following raw materials in parts by weight: 55 to 65 parts of fluorosilicone epoxy resin, 15 to 20 parts of hydrophobic modified nano Al2O3, 5 to 8 parts of TiO2 coated SiO2 core-shell material, 2 to 3 parts of silane coupling agent, 10 to 15 parts of butyl acetate and 0.5 to 1 part of photoinitiator TPO. According to the corrosion-resistant cross arm provided by the invention, the corrosion resistance of the cross arm is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of crossarm clamps, and in particular to a corrosion-resistant crossarm and a preparation method thereof. Background Art

[0002] In power transmission and distribution systems, crossarms serve as crucial supporting components for overhead lines, carrying conductors, insulators, and other equipment. The stability and reliability of their performance are directly linked to the safe operation of the entire power system. With the continuous development of the power industry and increasingly complex environmental conditions, higher requirements are being placed on the corrosion resistance of crossarms. Corrosion-resistant crossarms, which effectively resist environmental corrosion, extend service life, and reduce maintenance costs, have become a hot topic of research.

[0003] Corrosion-resistant crossarms are manufactured using specialized materials or surface treatments to resist chemical and electrochemical corrosion, enabling them to maintain their structural integrity and mechanical properties over time in a variety of harsh environmental conditions. They are primarily used on outdoor overhead power lines, where they withstand multiple external forces, including the weight of the conductors, wind loads, and ice loads, while preventing corrosion-related strength loss and breakage, ensuring the safe and stable operation of power lines.

[0004] Currently, common corrosion-resistant crossarms mainly include metal-based and composite-based crossarms. Metal-based crossarms are usually based on corrosion-resistant metal materials such as stainless steel and aluminum alloy, and their corrosion resistance is enhanced through alloying design or surface treatment processes. Composite-based crossarms are composed of reinforcing materials such as glass fiber and carbon fiber combined with a resin matrix, offering advantages such as light weight, high strength, and corrosion resistance.

[0005] Over long-term use, composite materials are susceptible to environmental factors such as ultraviolet light, oxygen, and moisture, leading to material aging and a gradual decline in performance. While some anti-aging measures have been implemented, such as adding antioxidants and applying surface protection, the aging resistance of composite materials still needs to be further improved. The aging problem of composite corrosion-resistant crossarms is particularly severe in areas with high temperatures, high humidity, and strong ultraviolet radiation. Based on this, the present invention provides a corrosion-resistant crossarm and a method for its preparation. Summary of the Invention

[0006] The present invention proposes a corrosion-resistant crossarm and a preparation method thereof, which improves the corrosion resistance of the crossarm to cope with complex environmental conditions, improves the local corrosion phenomenon and aging resistance of the crossarm caused by material problems, and ensures the safe and stable operation of the power line.

[0007] The technical solutions of the present invention are as follows: In a first aspect, the present invention provides a corrosion-resistant crossarm comprising a core layer and an outer layer; The core layer comprises the following matrix materials in parts by weight: 40-50 parts of bisphenol A epoxy resin, 5-10 parts of reactive diluent AGE, 3-5 parts of boron nitride micropowder, and 50-60 parts of methylhexahydrophthalic anhydride; and further comprises 60-70 wt% of glass fiber relative to the matrix materials; The outer layer comprises the following raw materials in parts by weight: 55-65 parts of fluorosilicone epoxy resin, 15-20 parts of hydrophobically modified nano-Al2O3, 5-8 parts of TiO2@SiO2 core-shell material, 2-3 parts of silane coupling agent, 10-15 parts of butyl acetate, and 0.5-1 part of photoinitiator TPO.

[0008] The present invention uses the physical barrier of hydrophobic Al2O3 and the chemical inertness of boron nitride to construct a triple protection system of "super-hydrophobic layer-thermal conductive channel-micro-defect filling", effectively blocking the penetration path of corrosive media and inhibiting electrochemical corrosion and thermal stress cracking. The TiO2@SiO2 core-shell structure forms a "light protection-thermal stability-interface enhancement" synergistic anti-aging network through photocatalytic inhibition and interface strengthening, combined with the UV shielding effect of fluorosilicone epoxy resin, significantly reducing UV-induced resin degradation and yellowing. The gradient curing process achieves a densified cross-linked structure through thermal stress regulation and molecular motion coordination; the microscopic reinforcement effect of boron nitride and core-shell materials, combined with the macroscopic load-bearing effect of glass fiber, constructs an integrated mechanical performance improvement system of "multi-scale reinforcement-gradient structure-interface optimization". Through the triple innovation of material formulation, preparation process and structural design, the present invention achieves long-life service of corrosion-resistant crossarms in complex environments. Its performance indicators are improved by 26%-78% compared with traditional products, providing an innovative solution for the protection of power facilities.

[0009] As a further technical solution, the preparation method of the hydrophobically modified nano-Al2O3 includes: calcining Al2O3 powder at 350-450°C for 2-3 hours; mixing KH-550 with anhydrous ethanol, adding glacial acetic acid to adjust the pH to 4-5, and magnetically stirring at 60-70°C for 30-40 minutes to form a hydrolyzed silane solution; adding the calcined Al2O3 thereto, and reacting at a constant temperature of 75-85°C and 700-800 rpm for 5-6 hours, and then centrifuging, washing, and drying to obtain the product.

[0010] As a further technical solution, the usage ratio of the Al2O3 powder, KH-550 and anhydrous ethanol is 100g: (1-3)g: (400-500)mL.

[0011] As a further technical solution, the preparation method of the TiO2@SiO2 core-shell material includes: dispersing nano-TiO2 in an ethanol solution containing hexadecyltrimethylammonium bromide, and ultrasonically treating it to form a suspension; mixing ethyl orthosilicate with ethanol, adding the mixture dropwise to the suspension, and simultaneously adding ammonia water to adjust the pH to 9-10; stirring the mixture at a constant temperature of 50-60°C for 10-12 hours, and forming a uniform SiO2 shell layer by a sol-gel method; and obtaining the material after centrifugation, washing, and drying.

[0012] As a further technical solution, the weight ratio of the nano-TiO2, hexadecyltrimethylammonium bromide and ethyl orthosilicate is 100:(20-40):(2-3).

[0013] As a further technical solution, the concentration of the hexadecyltrimethylammonium bromide ethanol solution is 0.4wt%-0.6wt%.

[0014] As a further technical solution, when the ethyl orthosilicate and ethanol are mixed, the usage ratio of the two is 1g: (9-11)mL.

[0015] In a second aspect, the present invention provides a method for preparing a corrosion-resistant crossarm, comprising the following steps: S1. Add bisphenol A epoxy resin, methylphenyl silicone resin, reactive diluent AGE, methylhexahydrophthalic anhydride and boron nitride to a vacuum mixing tank in sequence. Stir at a medium speed of 500-600 r / min for 30-40 minutes under a vacuum degree of 50-60 Pa, then switch to a high-speed stirring of 1000-1200 r / min for 30-40 minutes; add the mixed resin matrix to a glue tank preheated to 55-65°C, and pass the glass fiber through the glue tank at a speed of 50-60 mm / min to form a uniformly resin-wrapped prepreg. The prepreg enters a pultrusion die. The temperature in the die is controlled in sections, and the resin is gradually cured by gradient temperature increase; the formed core rod is subjected to a secondary heat treatment at 170-180°C for 2-3 hours; S2. Weigh the outer layer raw materials according to proportion, mix fluorosilicone epoxy resin, hydrophobically modified nano-Al2O3, TiO2@SiO2 core-shell material, silane coupling agent, butyl acetate, and photoinitiator TPO at 40-50°C and 200-300 rpm for 50-60 min, and let it stand for 10-15 min to obtain the outer layer rubber material; S3. Fix the formed core rod in a prefabricated shed mold, inject the outer layer of rubber into the mold, and obtain the corrosion-resistant crossarm after curing.

[0016] As a further technical solution, the temperature of the segmented temperature control in S1 is 150-160°C in the front section, 175-185°C in the middle section, and 160-170°C in the rear section.

[0017] As a further technical solution, the curing step includes: maintaining at 70-80°C for 1-2 hours, and then heating to 110-120°C and maintaining for 3-4 hours.

[0018] The working principle and beneficial effects of the present invention are: The corrosion-resistant crossarm of the present invention is modified with KH-550 silane coupling agent on the surface of Al2O3 to construct a super-hydrophobic interface. The principle is that the super-hydrophobic layer forms a lotus leaf structure by reducing the surface energy, making the corrosive medium (such as Cl - 、SO4 2- ) is difficult to adhere to and penetrate, effectively blocking the corrosion path; and the organic-inorganic hybrid layer formed by the silane coupling agent can inhibit the contact between water molecules and metal ions, reducing the occurrence of electrochemical corrosion reactions.

[0019] The present invention adopts a sol-gel method to coat a SiO2 shell layer on the TiO2 surface, wherein the SiO2 shell layer blocks direct contact between TiO2 and ultraviolet light, thereby preventing its photogenerated electron-hole pairs from inducing photooxidative degradation of the resin matrix; and the core-shell structure improves the interface bonding with the resin through the organic compatibility of the SiO2 shell layer, while the TiO2 core provides rigid support, thereby enhancing the overall mechanical properties of the composite material.

[0020] The introduction of boron nitride in the present invention achieves dual functional synergy. Its high thermal conductivity promotes uniform heat dissipation during the resin curing process and inhibits stress cracking caused by local heat accumulation. Nano-scale boron nitride particles fill the microscopic pores at the fiber-resin interface, improving the interface bonding strength through the mechanical interlocking effect and enhancing the load transfer efficiency.

[0021] The present invention adopts a three-stage heating mode (front section 150-160°C → middle section 175-185°C → back section 160-170°C), wherein the low temperature in the front section promotes chain segment slippage to achieve uniform infiltration, the high temperature in the middle section accelerates the cross-linking reaction to form a three-dimensional network, and the cooling in the back section inhibits side reactions to minimize internal stress; and the gradient heating avoids the uneven reaction rate caused by single temperature curing, reduces the probability of microcrack initiation, and improves the density of the material.

[0022] The present invention uses multi-scale interface reinforcement of the core-shell-fiber-matrix. The TiO2@SiO2 core-shell material is regulated by the shell thickness to achieve photocatalytic inhibition at the nanoscale. At the same time, the hydroxyl groups on the SiO2 surface form a hydrogen bond network with the resin, thereby enhancing the micron-level fiber-resin interface bonding. The hydrophobic Al2O3 and boron nitride form a "rigid and flexible" structure at the mesoscale: Al2O3 provides wear resistance, and boron nitride (layered structure) dissipates crack energy through a slip mechanism.

[0023] The fluorosilicone epoxy resin and hydrophobic Al2O3 of the present invention form a "maze effect" protective layer, which requires corrosive media to penetrate multiple physical / chemical barriers, thereby improving acid resistance. The synergistic effect of TiO2@SiO2 and the silane coupling agent: the core-shell material inhibits light aging, and the coupling agent connects the organic / inorganic phases through -Si-O- bonds, improving the adhesion of the coating, and reaching level 0 using the cross-hatch test.

[0024] Specific implementation methods The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. It should be noted that the bisphenol A epoxy resin model in the present invention is E-51; the active diluent AGE, CAS No.: 68609-97-2, is purchased from Hubei Green Home Materials Technology Co., Ltd.; the fluorosilicone epoxy resin, 30% fluorine content, is purchased from Hubei Maidehao Biotechnology Co., Ltd.; and the boron nitride powder is purchased from Huifa Chemical.

[0025] Example 1 This embodiment provides a corrosion-resistant crossarm, comprising a core layer and an outer layer; The core layer comprises the following matrix materials in parts by weight: 45 parts of bisphenol A epoxy resin, 7 parts of reactive diluent AGE, 4 parts of boron nitride micropowder, and 55 parts of methylhexahydrophthalic anhydride; and also comprises 65 wt% of glass fiber relative to the matrix materials. The outer layer includes the following raw materials in parts by weight: 60 parts of fluorosilicone epoxy resin, 17 parts of hydrophobically modified nano-Al2O3, 6 parts of TiO2@SiO2 core-shell material, 2.5 parts of silane coupling agent KH-560, 12 parts of butyl acetate, and 0.7 parts of photoinitiator TPO.

[0026] The preparation method of hydrophobically modified nano-Al2O3 includes: calcining 100g Al2O3 powder at 400℃ for 2.5h; mixing 2g KH-550 with 450mL anhydrous ethanol, adding glacial acetic acid to adjust the pH to 4.5, and magnetically stirring at 65℃ for 35min to form a hydrolyzed silane solution; adding the calcined Al2O3 to the solution, and reacting at 80℃ and 750rpm for 5.5h, centrifuging, washing with deionized water, and drying at 60℃ to obtain the product.

[0027] Among them, the preparation method of TiO2@SiO2 core-shell material includes: dispersing nano-TiO2 in an ethanol solution containing hexadecyltrimethylammonium bromide, and ultrasonically treating it to form a suspension; mixing ethyl orthosilicate with ethanol, adding it dropwise to the suspension, and simultaneously adding ammonia water to adjust the pH to 9.5; stirring and reacting at a constant temperature of 55°C for 11 hours, and forming a uniform SiO2 shell layer by a sol-gel method; centrifuging, washing with deionized water and ethanol respectively, and drying at 60°C to obtain the material; the weight ratio of nano-TiO2, hexadecyltrimethylammonium bromide and ethyl orthosilicate is 100:30:2.5; the concentration of the ethanol solution of hexadecyltrimethylammonium bromide is 0.5wt%; when ethyl orthosilicate and ethanol are mixed, the usage ratio of the two is 1g:10mL.

[0028] A method for preparing a corrosion-resistant crossarm comprises the following steps: S1. Add bisphenol A epoxy resin, methylphenyl silicone resin, active diluent AGE, methylhexahydrophthalic anhydride and boron nitride to a vacuum mixing tank in sequence. Stir at a medium speed of 550 r / min for 35 minutes under a vacuum degree of 55 Pa, and then switch to a high-speed stirring of 1100 r / min for 35 minutes. Add the mixed resin matrix to a glue tank preheated to 60°C. Pass the glass fiber through the glue tank at a speed of 55 mm / min to form a uniformly resin-wrapped prepreg. The prepreg enters the pultrusion die. The temperature in the die is controlled in sections, with the front section temperature at 155°C, the middle section temperature at 180°C, and the rear section temperature at 165°C. The resin is gradually cured by gradient heating. The formed core rod is subjected to a secondary heat treatment at 175°C for 2.5 hours. S2. Weigh the outer layer raw materials according to proportion, mix fluorosilicone epoxy resin, hydrophobically modified nano-Al2O3, TiO2@SiO2 core-shell material, silane coupling agent, butyl acetate, and photoinitiator TPO at 45°C and 250 rpm for 55 min, and let it stand for 12 min to obtain the outer layer rubber material; S3. Fix the formed core rod in a prefabricated shed mold, inject the outer layer of rubber into the mold, maintain it at 75°C for 1.5 hours, then heat it to 115°C and maintain it for 3.5 hours to solidify it to obtain a corrosion-resistant crossarm.

[0029] Example 2 This embodiment provides a corrosion-resistant crossarm, comprising a core layer and an outer layer; The core layer comprises the following matrix materials in parts by weight: 40 parts of bisphenol A epoxy resin, 5 parts of reactive diluent AGE, 3 parts of boron nitride powder, and 50 parts of methyl hexahydrophthalic anhydride; and also comprises 60 wt% of glass fiber relative to the matrix materials; The outer layer includes the following raw materials in parts by weight: 55 parts of fluorosilicone epoxy resin, 15 parts of hydrophobically modified nano-Al2O3, 5 parts of TiO2@SiO2 core-shell material, 2 parts of silane coupling agent KH-560, 10 parts of butyl acetate, and 0.5 parts of photoinitiator TPO.

[0030] The preparation method of hydrophobically modified nano-Al2O3 includes: calcining 100g Al2O3 powder at 350°C for 2h; mixing 1g KH-550 with 400mL anhydrous ethanol, adding glacial acetic acid to adjust the pH to 4, and magnetically stirring at 60°C for 30min to form a hydrolyzed silane solution; adding the calcined Al2O3 thereto, reacting at 75°C and 700rpm for 5h, centrifuging, washing with deionized water, and drying at 60°C to obtain the product.

[0031] Among them, the preparation method of TiO2@SiO2 core-shell material includes: dispersing nano-TiO2 in an ethanol solution containing hexadecyltrimethylammonium bromide, and ultrasonically treating it to form a suspension; mixing ethyl orthosilicate with ethanol, adding it dropwise to the suspension, and simultaneously adding ammonia water to adjust the pH to 9; stirring and reacting at a constant temperature of 50°C for 10 hours, and forming a uniform SiO2 shell layer by a sol-gel method; centrifuging, washing with deionized water and ethanol respectively, and drying at 60°C to obtain the material; the weight ratio of nano-TiO2, hexadecyltrimethylammonium bromide and ethyl orthosilicate is 100:20:2; the concentration of the ethanol solution of hexadecyltrimethylammonium bromide is 0.4wt%; the dosage ratio of ethyl orthosilicate and ethanol when the two are mixed is 1g:9mL.

[0032] A method for preparing a corrosion-resistant crossarm comprises the following steps: S1. Add bisphenol A epoxy resin, methylphenyl silicone resin, active diluent AGE, methylhexahydrophthalic anhydride and boron nitride to a vacuum mixing tank in sequence. Stir at a medium speed of 500 r / min for 30 min under a vacuum degree of 50 Pa, then switch to a high-speed stirring of 1000 r / min for 30 min. Add the mixed resin matrix to a glue tank preheated to 55°C. Pass the glass fiber through the glue tank at a speed of 50 mm / min to form a uniformly resin-wrapped prepreg. The prepreg enters the pultrusion die. The temperature in the die is controlled in sections, with the front section temperature at 150°C, the middle section temperature at 175°C, and the rear section temperature at 160°C. The resin is gradually cured by gradient heating. The formed core rod is subjected to a secondary heat treatment at 170°C for 2 h. S2. Weigh the outer layer raw materials according to proportion, mix fluorosilicone epoxy resin, hydrophobically modified nano-Al2O3, TiO2@SiO2 core-shell material, silane coupling agent, butyl acetate, and photoinitiator TPO at 40°C and 200 rpm for 50 min, and let it stand for 10 min to obtain the outer layer rubber material; S3. Fix the formed core rod in a prefabricated shed mold, inject the outer layer of rubber into the mold, maintain it at 70°C for 1 hour, then heat it to 110°C and maintain it for 3 hours to solidify to obtain a corrosion-resistant crossarm.

[0033] Example 3 This embodiment provides a corrosion-resistant crossarm, comprising a core layer and an outer layer; The core layer comprises the following matrix materials in parts by weight: 50 parts of bisphenol A epoxy resin, 10 parts of reactive diluent AGE, 5 parts of boron nitride powder, and 60 parts of methylhexahydrophthalic anhydride; and also comprises 70 wt% of glass fiber relative to the matrix materials. The outer layer includes the following raw materials in parts by weight: 65 parts of fluorosilicone epoxy resin, 20 parts of hydrophobically modified nano-Al2O3, 8 parts of TiO2@SiO2 core-shell material, 3 parts of silane coupling agent KH-560, 15 parts of butyl acetate, and 1 part of photoinitiator TPO.

[0034] The preparation method of hydrophobically modified nano-Al2O3 includes: calcining 100g Al2O3 powder at 450℃ for 3h; mixing 3g KH-550 with 500mL anhydrous ethanol, adding glacial acetic acid to adjust the pH to 5, and magnetically stirring at 70℃ for 40min to form a hydrolyzed silane solution; adding the calcined Al2O3 to the solution, reacting at 85℃ and 800rpm for 6h, centrifuging, washing with deionized water, and drying at 60℃ to obtain the product.

[0035] Among them, the preparation method of TiO2@SiO2 core-shell material includes: dispersing nano-TiO2 in an ethanol solution containing hexadecyltrimethylammonium bromide, and ultrasonically treating it to form a suspension; mixing ethyl orthosilicate with ethanol, adding it dropwise to the suspension, and simultaneously adding ammonia water to adjust the pH to 10; stirring and reacting at a constant temperature of 60°C for 12 hours, and forming a uniform SiO2 shell layer through a sol-gel method; centrifuging, washing with deionized water and ethanol respectively, and drying at 60°C to obtain the material; the weight ratio of nano-TiO2, hexadecyltrimethylammonium bromide and ethyl orthosilicate is 100:40:3; the concentration of the ethanol solution of hexadecyltrimethylammonium bromide is 0.6wt%; when ethyl orthosilicate and ethanol are mixed, the usage ratio of the two is 1g:11mL.

[0036] A method for preparing a corrosion-resistant crossarm comprises the following steps: S1. Add bisphenol A epoxy resin, methylphenyl silicone resin, active diluent AGE, methylhexahydrophthalic anhydride and boron nitride to a vacuum mixing tank in sequence. Stir at a medium speed of 600 r / min for 40 min under a vacuum degree of 60 Pa, and then switch to a high-speed stirring of 1200 r / min for 40 min. Add the mixed resin matrix to a glue tank preheated to 65°C. Pass the glass fiber through the glue tank at a speed of 60 mm / min to form a uniformly resin-wrapped prepreg. The prepreg enters the pultrusion die. The temperature in the die is controlled in sections, with the front section temperature at 160°C, the middle section temperature at 185°C, and the rear section temperature at 170°C. The resin is gradually cured by gradient heating. The formed core rod is subjected to a secondary heat treatment at 180°C for 3 h. S2. Weigh the outer layer raw materials according to proportion, mix fluorosilicone epoxy resin, hydrophobically modified nano-Al2O3, TiO2@SiO2 core-shell material, silane coupling agent, butyl acetate, and photoinitiator TPO at 50°C and 300 rpm for 60 min, and let it stand for 15 min to obtain the outer layer rubber material; S3. Fix the formed core rod in a prefabricated shed mold, inject the outer layer of rubber into the mold, maintain it at 80°C for 2 hours, then heat it to 120°C and maintain it for 4 hours to solidify it to obtain a corrosion-resistant crossarm.

[0037] Example 4 This embodiment provides a corrosion-resistant crossarm, comprising a core layer and an outer layer; The core layer comprises the following matrix materials in parts by weight: 40 parts of bisphenol A epoxy resin, 10 parts of reactive diluent AGE, 3 parts of boron nitride powder, and 60 parts of methyl hexahydrophthalic anhydride; and also comprises 60 wt% of glass fiber relative to the matrix materials; The outer layer includes the following raw materials in parts by weight: 65 parts of fluorosilicone epoxy resin, 15 parts of hydrophobically modified nano-Al2O3, 8 parts of TiO2@SiO2 core-shell material, 2 parts of silane coupling agent KH-560, 15 parts of butyl acetate, and 0.5 parts of photoinitiator TPO.

[0038] The preparation method of hydrophobically modified nano-Al2O3 includes: calcining 100g Al2O3 powder at 450°C for 2h; mixing 3g KH-550 with 400mL anhydrous ethanol, adding glacial acetic acid to adjust the pH to 5, and magnetically stirring at 60°C for 40min to form a hydrolyzed silane solution; adding the calcined Al2O3 thereto, reacting at a constant temperature of 75°C and 800rpm for 5h, centrifuging, washing with deionized water, and drying at 60°C to obtain the product.

[0039] Among them, the preparation method of TiO2@SiO2 core-shell material includes: dispersing nano-TiO2 in an ethanol solution containing hexadecyltrimethylammonium bromide, and ultrasonically treating it to form a suspension; mixing ethyl orthosilicate with ethanol, adding it dropwise to the suspension, and simultaneously adding ammonia water to adjust the pH to 10; stirring and reacting at a constant temperature of 50°C for 12 hours, and forming a uniform SiO2 shell layer through a sol-gel method; centrifuging, washing with deionized water and ethanol respectively, and drying at 60°C to obtain the material; the weight ratio of nano-TiO2, hexadecyltrimethylammonium bromide and ethyl orthosilicate is 100:20:3; the concentration of the ethanol solution of hexadecyltrimethylammonium bromide is 0.4wt%; when ethyl orthosilicate and ethanol are mixed, the usage ratio of the two is 1g:11mL.

[0040] A method for preparing a corrosion-resistant crossarm comprises the following steps: S1. Add bisphenol A epoxy resin, methylphenyl silicone resin, active diluent AGE, methylhexahydrophthalic anhydride and boron nitride to a vacuum mixing tank in sequence. Stir at a medium speed of 600 r / min for 30 min under a vacuum degree of 50 Pa, then switch to a high-speed stirring of 1200 r / min for 30 min. Add the mixed resin matrix to a glue tank preheated to 65°C. Pass the glass fiber through the glue tank at a speed of 50 mm / min to form a uniformly resin-wrapped prepreg. The prepreg enters the pultrusion die. The temperature in the die is controlled in sections, with the front section temperature at 160°C, the middle section temperature at 175°C, and the rear section temperature at 170°C. The resin is gradually cured by gradient heating. The formed core rod is subjected to a secondary heat treatment at 170°C for 3 h. S2. Weigh the outer layer raw materials according to proportion, mix fluorosilicone epoxy resin, hydrophobically modified nano-Al2O3, TiO2@SiO2 core-shell material, silane coupling agent, butyl acetate, and photoinitiator TPO at 40°C and 300 rpm for 50 min, and let it stand for 15 min to obtain the outer layer rubber material; S3. Fix the formed core rod in a prefabricated shed mold, inject the outer layer of rubber into the mold, maintain it at 70°C for 2 hours, then heat it to 110°C and maintain it for 4 hours to solidify it to obtain a corrosion-resistant crossarm.

[0041] Comparative Example 1 In Comparative Example 1, the nano-Al2O3 was not hydrophobically modified, and the rest was the same as in Example 1, and the preparation steps were the same as in Example 1.

[0042] Comparative Example 2 In Comparative Example 2, the outer layer raw material does not include hydrophobically modified nano-Al2O3, and the rest is the same as in Example 1, and the preparation steps are the same as in Example 1.

[0043] Comparative Example 3 In Comparative Example 3, the TiO2@SiO2 core-shell material is replaced with nano-TiO2, and the rest is the same as in Example 1, and the preparation steps are the same as in Example 1.

[0044] Comparative Example 4 In Comparative Example 4, the TiO2@SiO2 core-shell material is replaced by silicon dioxide, and the rest is the same as in Example 1, and the preparation steps are the same as in Example 1.

[0045] Comparative Example 5 In Comparative Example 5, no TiO2@SiO2 core-shell material was added, and the rest was the same as in Example 1, and the preparation steps were the same as in Example 1.

[0046] Comparative Example 6 In Comparative Example 6, no boron nitride powder was added; the rest was the same as in Example 1, and the preparation steps were the same as in Example 1.

[0047] Test Example 1: The corrosion-resistant crossarms prepared in Examples 1-4 and Comparative Examples 1-6 were tested as follows: Neutral salt spray test: Refer to GB / T 10125-2021 for testing, 5% NaCl solution, temperature 35°C, continuous spraying for 5000 hours, and calculate the surface corrosion area rate (%); Mechanical properties test: Tested in accordance with GB / T 1449-2005, with a span of 200 mm and a loading speed of 2 mm / min, and the bending strength (MPa) was calculated. Chemical medium immersion test: The specimens were immersed in H2SO4 solution with pH=2 and NaOH solution with pH=12 (60°C), and the flexural strength retention rate was tested after 30 days. Anti-aging performance test: Tested according to GB / T 23987-2009, UVB-313 lamp, irradiation intensity 0.76W / m 2 , 60℃ / 8h illumination + 50℃ / 4h condensation, cycle for 3000 hours, calculate the yellowing index Δb; The results are shown in Table 1 below: Table 1

[0048] Combined with the above, the corrosion area rates of Examples 1-4 are all less than 1%, while those of Comparative Example 1 are as high as 8.5% and Comparative Example 2 reaches 12.3%, demonstrating that hydrophobically modified Al2O3 effectively blocks the penetration of corrosive media. The acid / base strength retention rate of Example 1 is >95%, significantly higher than that of Comparative Examples 1 and 2, indicating that the hydrophobic layer significantly reduces the chemical corrosion rate. The yellowing index Δb of Example 1 is 0.8, a 62% decrease compared to Comparative Example 3 and a 78% decrease compared to Example 4, demonstrating that the core-shell structure (TiO2@SiO2) suppresses TiO2 photocatalytic activity through SiO2 encapsulation, preventing resin degradation. The flexural strength of Example 1 is 13.1% higher than that of Comparative Example 5, demonstrating that the core-shell material enhances overall strength by strengthening interfacial bonding.

[0049] In addition, the outer layer of Example 3 contains 20% modified Al2O3 and 8% core-shell material, and the flexural strength (585 MPa) and acid resistance (98.1%) are both optimal, demonstrating the synergistic reinforcement effect of the high filler ratio and the resin matrix.

[0050] Therefore, hydrophobically modified Al2O3 and the core-shell TiO2@SiO2 structure are key to improving corrosion and aging resistance. Examples 1-4 all exhibited salt spray corrosion area rates less than 1%, and UV aging Δb ≤ 1.5, far exceeding industry standards. The gradient curing process and boron nitride micropowder synergistically enhance mechanical properties. Example 1 achieved a flexural strength of 568 MPa, a 26% improvement over conventional crossarms. Unmodified Al2O3 (Comparative Example 1) exhibited a corrosion area rate of 8.5%, while the absence of the core-shell material (Comparative Example 5) resulted in a yellowing index of 4.5, demonstrating the indispensability of these innovative components.

[0051] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A corrosion-resistant crossarm, characterized in that: including a core layer and an outer layer; The core layer comprises the following matrix materials in parts by weight: 40-50 parts of bisphenol A epoxy resin, 5-10 parts of reactive diluent AGE, 3-5 parts of boron nitride micropowder, and 50-60 parts of methylhexahydrophthalic anhydride; and further comprises 60-70 wt% of glass fiber relative to the matrix materials; The outer layer comprises the following raw materials in parts by weight: 55-65 parts of fluorosilicone epoxy resin, 15-20 parts of hydrophobically modified nano-Al2O3, 5-8 parts of TiO2@SiO2 core-shell material, 2-3 parts of silane coupling agent, 10-15 parts of butyl acetate, and 0.5-1 part of photoinitiator TPO.

2. The corrosion-resistant crossarm according to claim 1, characterized in that: The preparation method of the hydrophobically modified nano-Al2O3 comprises: calcining Al2O3 powder at 350-450°C for 2-3 hours; mixing KH-550 with anhydrous ethanol, adding glacial acetic acid to adjust the pH to 4-5, and magnetically stirring at 60-70°C for 30-40 minutes to form a hydrolyzed silane solution; adding the calcined Al2O3 to the solution, and reacting at 75-85°C and 700-800 rpm for 5-6 hours, and then centrifuging, washing, and drying to obtain the hydrolyzed silane solution.

3. The corrosion-resistant crossarm according to claim 2, characterized in that: The usage ratio of the Al2O3 powder, KH-550 and anhydrous ethanol is 100g: (1-3)g: (400-500)mL.

4. The corrosion-resistant crossarm according to claim 1, characterized in that: The preparation method of the TiO2@SiO2 core-shell material comprises: dispersing nano-TiO2 in an ethanol solution containing hexadecyltrimethylammonium bromide, and ultrasonically treating the solution to form a suspension; mixing ethyl orthosilicate with ethanol, and adding the mixture dropwise to the suspension, while simultaneously adding aqueous ammonia to adjust the pH to 9-10; reacting the mixture at a constant temperature of 50-60°C with stirring for 10-12 hours, and forming a uniform SiO2 shell layer by a sol-gel method; and finally obtaining the TiO2 core-shell material by centrifugation, washing, and drying.

5. The corrosion-resistant crossarm according to claim 4, characterized in that: The weight ratio of the nano-TiO2, hexadecyltrimethylammonium bromide and ethyl orthosilicate is 100:(20-40):(2-3).

6. The corrosion-resistant crossarm according to claim 4, characterized in that: The concentration of the hexadecyltrimethylammonium bromide ethanol solution is 0.4 wt %-0.6 wt %.

7. The corrosion-resistant crossarm according to claim 1, characterized in that: When the ethyl orthosilicate and ethanol are mixed, the usage ratio of the two is 1g: (9-11)mL.

8. A method for preparing a corrosion-resistant crossarm according to any one of claims 1 to 7, characterized in that the steps include: S1. Add bisphenol A epoxy resin, methylphenyl silicone resin, reactive diluent AGE, methylhexahydrophthalic anhydride and boron nitride to a vacuum mixing tank in sequence. Stir at a medium speed of 500-600 r / min for 30-40 minutes under a vacuum degree of 50-60 Pa, then switch to a high-speed stirring of 1000-1200 r / min for 30-40 minutes; add the mixed resin matrix to a glue tank preheated to 55-65°C, and pass the glass fiber through the glue tank at a speed of 50-60 mm / min to form a uniformly resin-wrapped prepreg. The prepreg enters a pultrusion die. The temperature in the die is controlled in sections, and the resin is gradually cured by gradient temperature increase; the formed core rod is subjected to a secondary heat treatment at 170-180°C for 2-3 hours; S2. Weigh the outer layer raw materials according to proportion, mix fluorosilicone epoxy resin, hydrophobically modified nano-Al2O3, TiO2@SiO2 core-shell material, silane coupling agent, butyl acetate, and photoinitiator TPO at 40-50°C and 200-300 rpm for 50-60 min, and let it stand for 10-15 min to obtain the outer layer rubber material; S3. Fix the formed core rod in a prefabricated shed mold, inject the outer layer of rubber into the mold, and obtain the corrosion-resistant crossarm after curing.

9. The method for preparing a corrosion-resistant crossarm according to claim 8, characterized in that: The temperature of the segmented temperature control in S1 is 150-160°C in the front section, 175-185°C in the middle section, and 160-170°C in the rear section.

10. The corrosion-resistant crossarm according to claim 8, characterized in that: The curing step includes: maintaining the temperature at 70-80° C. for 1-2 hours, and then heating to 110-120° C. and maintaining the temperature for 3-4 hours.

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