Fluorine-containing polymer modified epoxy resin composite insulator core rod and manufacturing method thereof

Abstract

The invention provides a fluorine-containing polymer modified epoxy resin composite insulator core rod and a manufacturing method thereof. The fluorine-containing polymer modified epoxy resin composite insulator core rod comprises glass fibers, matrix resin, a curing agent, fluorinated carbon nanotubes, epoxy group-containing fluorosilicone POSS, nano SiO2, micron SiC and a silane coupling agent. According to the invention, fillers with different sizes are designed, the fillers form a density gradient through centrifugation, and a continuous gradient structure spontaneously formed in single-layer resin is matched, so that interface mutation is avoided, the material is tough inside and rigid outside, and meanwhile, the epoxy group-containing fluorosilicone POSS is'extruded 'to a middle transition area by the fillers during centrifugation, so that the material is more stable in performance. And during curing, migration to the outer layer is realized through chemical anchoring and the surface enrichment effect of fluorine atoms, so that gradient fluorine-containing is formed, and a super-hydrophobic outer layer is realized through low-fluorine modification.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of insulator core rod preparation, in particular to a fluorine-containing polymer modified epoxy resin composite insulator core rod and a manufacturing method thereof. BACKGROUND

[0002] As a key component for support and insulation, the composite insulator core rod is usually made of glass fiber reinforced epoxy resin composite material, and its performance defects have become one of the bottlenecks restricting the development of extra-high voltage power transmission technology. The current mainstream core rod material faces three major technical challenges: internal stress problems caused by uneven curing, interfacial defects and environmental risks of high fluorine modification. These problems are particularly prominent under complex working conditions such as high temperature, high humidity and strong electric field, seriously affecting the long-term reliability and safety of the insulator.

[0003] The modified resin disclosed in the patent with the publication number CN112592560A reduces the internal stress of the material and reduces the cracking problem by controlling the curing speed and adding a release agent, but the non-reactive release agent component introduced forms a weak interface region inside the core rod. This leads to a decrease in the coupling rate of glass fiber and resin, significantly increasing the dispersion of material mechanical strength. Under dynamic load, these weak interface regions are prone to become the starting point of crack initiation and propagation, ultimately leading to the destruction of the core rod under a stress lower than the theoretical strength.

[0004] The patent with the publication number CN118063968B uses a multi-layer composite structure design to achieve performance gradient distribution, but in the actual manufacturing process, due to the differences in the thermal expansion coefficient and elastic modulus of different layers of material, there will be obvious stress concentration at the interfacial interface, and interfacial peeling failure is more likely to occur in environments with drastic temperature fluctuations. In addition, the multi-layer structure also increases the complexity of the manufacturing process, increases production costs, and reduces the economic efficiency and market competitiveness of the product.

[0005] Fluoride modification is the current mainstream method for improving the hydrophobicity of the core rod surface. By physically blending fluorinated carbon nanotubes (F-CNTs), the contact angle can reach an excellent level of 112°. However, when the fluorine content exceeds 10%, the impact strength of the material will decrease sharply to 4.2 kJ / m², seriously affecting the mechanical reliability of the core rod. More seriously, the fluorine component is prone to migration and loss during long-term use, not only leading to the gradual degradation of hydrophobicity, but also possibly causing environmental pollution.

[0006] With the development of extra-high voltage power transmission technology, the performance defects of traditional composite insulator core rods under complex working conditions are increasingly prominent, so it is urgent to develop a low-fluorine modification strategy that can maintain excellent hydrophobicity without sacrificing mechanical performance and environmental friendliness. At the same time, through innovative gradient design, the problems of interfacial defects and internal stress concentration can be avoided. SUMMARY

[0007] (1) Technical problems solved

[0008] In view of the deficiencies of the prior art, the present invention provides a fluoropolymer modified epoxy resin composite insulator core rod and a manufacturing method thereof to solve the problems raised in the above background technology.

[0009] (2) Technical solution

[0010] To achieve the above objectives, the present invention is implemented through the following technical solutions: A fluorine-containing polymer modified epoxy resin composite insulator core rod, comprising, by weight percentage:

[0011] Glass fiber 70% to 80%;

[0012] Epoxy resin matrix 20% to 30%;

[0013] The epoxy resin matrix includes the following raw materials in parts by weight:

[0014] 100 parts of base resin;

[0015] 75.5 parts of curing agent;

[0016] 1.5 parts of fluorinated carbon nanotubes;

[0017] Contains 5 parts of epoxy fluorosilicone POSS;

[0018] 5 parts of nano-SiO2;

[0019] 15 parts of micron SiC;

[0020] 3 parts of silane coupling agent.

[0021] As a further preferred embodiment, the fluorinated carbon nanotubes have a fluorine content of 30% to 40% and a density of 1.8 to 2.0 g / cm 3 , the matrix resin density is 1.1~1.2g / cm 3 .

[0022] As a further preference, the nano-SiO2 is a spherical particle with a diameter of 10-15 nm, and the micron SiC is a spherical particle with a diameter of 50-60 μm.

[0023] As a further preference, the density of epoxy-containing fluorosilicone POSS is 1.8 to 2.0 g / cm 3 , the molecular structure is:

[0024] ;

[0025] Where R is a perfluoroalkyl group -C2H4-C n F 2n+1 , n is any integer between 5 and 8.

[0026] As a further preference, the silane coupling agent is one or more of γ-aminopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, and γ-glycidoxypropyltrimethoxysilane.

[0027] As a further preference, the base resin comprises the following raw materials in parts by weight:

[0028] 55-65 parts of bisphenol A epoxy resin;

[0029] 10-15 parts of trifunctional epoxy resin;

[0030] 20-25 parts of bisphenol F epoxy resin.

[0031] As further preferred, the trifunctional epoxy resin is one or more of triglycidyl p-aminophenol and tetraglycidyl diaminodiphenylmethane.

[0032] As a further preference, the curing agent comprises the following raw materials in parts by weight:

[0033] 30 parts of polyetheramine D400;

[0034] 45 parts of methyltetrahydrophthalic anhydride;

[0035] 0.5 parts of 2,4,6-tris(dimethylaminomethyl)phenol.

[0036] A method for manufacturing a fluorine-containing polymer modified epoxy resin composite insulator core rod, wherein the method comprises the following steps:

[0037] ① Place bisphenol A epoxy resin, trifunctional epoxy resin and bisphenol F epoxy resin in a reaction kettle in proportion and mix them to obtain a uniformly mixed matrix resin;

[0038] ② After mixing polyetheramine D400 and methyltetrahydrophthalic anhydride, add 2,4,6-tris(dimethylaminomethyl)phenol and mix again to obtain a curing agent system;

[0039] ③ Add corresponding weight fractions of nano-SiO2 and micron-SiC to the matrix resin one by one, disperse them evenly by ultrasonication, add corresponding weight fractions of fluorinated carbon nanotubes and epoxy-containing fluorosilicon POSS, emulsify them using a high-speed shear emulsifier, slowly pour in the curing agent system, mix them evenly, and vacuum degas to obtain a homogeneous epoxy resin matrix;

[0040] ④ Arrange glass fibers of corresponding weight fractions in a unidirectional manner and place them in a glue tank. Inject a homogeneous epoxy resin matrix into the mold, centrifuge at 800 rpm for 10-15 minutes, immediately heat and cure in sections, and pultrude to obtain a cylindrical core rod.

[0041] The staged heating curing includes: the first stage is 80°C constant temperature for 2 hours; the second stage is 120°C constant temperature for 3 hours; the third stage is 160°C constant temperature for 4 hours;

[0042] ⑤ After being kept at 160℃ for 2 hours, the temperature is gradually lowered (10℃ / h) to room temperature to eliminate the internal stress and obtain the composite insulator core rod.

[0043] (3) Beneficial effects

[0044] The present invention provides a fluorine-containing polymer modified epoxy resin composite insulator core rod and a manufacturing method thereof, which has the following beneficial effects:

[0045] The present invention designs fillers of nano-SiO2 and micron-SiC of different sizes. During centrifugation, the difference in particle sedimentation rate causes the inner SiO2 layer and the outer SiC layer to form a density gradient in the radial direction, "squeezing" the epoxy-containing fluorosilicon POSS to the middle transition zone. At the same time, by combining with epoxy resin and through the gradient distribution of the filler, the hardness of the outer layer of the core rod is increased while the toughness of the inner layer is maintained, forming a tough-inner-outer-rigid structure suitable for the complex working conditions of ultra-high voltage insulators.

[0046] Moreover, by centrifugal action and the difference in diffusion rates between the rigid curing agent and the flexible curing agent in the resin, the rigid curing agent is concentrated in the outer layer, while the flexible curing agent is distributed in the inner layer. By controlling the diffusion of the curing agent and curing with a temperature gradient, a spontaneous cross-linking gradient is achieved within the single layer of resin, forming a continuous gradient structure, avoiding interface mutations, and at the same time avoiding interface defects in the multi-layer stacking process.

[0047] Finally, the epoxy-containing fluorosilicone POSS is "squeezed" into the middle transition zone by the filler during centrifugation. During solidification, the chemical anchoring produced by the reaction with methyltetrahydrophthalic anhydride and the surface enrichment effect of fluorine atoms migrate to the outer layer, forming a gradient fluorine content. It cooperates with the F-CNTs settled to the outer layer to enhance the hydrophobicity of the core rod surface. The surface fluorine content is less than 8%, and the chemical anchoring reduces the subsequent migration and loss of fluorine, achieving low-fluorine modification. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0049] Figure 1 The present invention is a schematic diagram of the manufacturing process of a fluorine-containing polymer modified epoxy resin composite insulator core rod. DETAILED DESCRIPTION

[0050] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0051] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0052] In one aspect, the present invention provides a fluorine-containing polymer modified epoxy resin composite insulator core rod, comprising, by weight percentage:

[0053] Glass fiber 70% to 80%;

[0054] Epoxy resin matrix 20% to 30%.

[0055] The epoxy resin matrix includes the following raw materials in parts by weight:

[0056] 100 parts of base resin;

[0057] 75.5 parts of curing agent;

[0058] 1.5 parts of fluorinated carbon nanotubes (F-CNTs);

[0059] Contains 5 parts of epoxy fluorosilicone POSS;

[0060] 5 parts of nano-SiO2;

[0061] 15 parts of micron SiC;

[0062] 3 parts of silane coupling agent;

[0063] Among them, F-CNTs, fluorine content 30% ~ 40%, density 1.8 ~ 2.0g / cm 3, higher than the resin density 1.1 ~ 1.2g / cm 3 By centrifugation, F-CNTs are enriched in the outer layer of the epoxy resin matrix, thereby improving the hydrophobicity and wear resistance of the outer layer of the epoxy resin matrix.

[0064] Among them, nano-SiO2 is spherical particles with a diameter of 10-15nm, and micron-SiC is spherical particles with a diameter of 50-60um. During centrifugation, the sedimentation rate of nano-SiO2 is slow and concentrated in the inner layer, while the sedimentation rate of micron-SiC is fast and enriched in the surface layer. The SiO2 in the inner layer and the SiC in the outer layer form a density gradient along the radial direction. During centrifugation, the epoxy-containing fluorosilicone POSS is "squeezed" to the middle transition zone and combines with the epoxy resin to improve the bonding strength of the inner and outer layers.

[0065] Among them, the silane coupling agent is one or more of γ-aminopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, and γ-glycidyloxypropyltrimethoxysilane, which is used to improve the bonding strength between the epoxy resin matrix and the glass fiber.

[0066] The base resin is in parts by weight and includes the following raw materials:

[0067] Bisphenol A epoxy resin (E-44) 55-65 parts;

[0068] Trifunctional epoxy resin (TGIC) 10-15 parts;

[0069] 20-25 parts of bisphenol F epoxy resin;

[0070] Among them, bisphenol A epoxy resin, as a base resin, provides mechanical strength. In this embodiment, the bisphenol A epoxy resin is selected from Baling Petrochemical, model CYD-128 / E44, with an epoxy value of 0.44-0.51, to ensure crosslinking density;

[0071] The trifunctional epoxy resin improves the crosslinking density of the outer layer. In this embodiment, the trifunctional epoxy resin is one or more of triglycidyl para-aminophenol and tetraglycidyl diaminodiphenylmethane, selected from Shanghai Resin Factory, model 680 series, with an epoxy value of 0.85-1.0, giving the epoxy resin matrix a higher crosslinking density and better heat resistance, mechanical strength and chemical stability.

[0072] Bisphenol F epoxy resin reduces the overall viscosity and improves the fluidity and wettability of the resin system. In this embodiment, the bisphenol F epoxy resin is selected from Baling Petrochemical, model CYDEF-200, epoxy equivalent: 160-180 g / eq, to ​​enhance the reaction activity.

[0073] Furthermore, the curing agent includes the following raw materials in parts by weight:

[0074] 30 parts of polyetheramine D400;

[0075] 45 parts of methyltetrahydrophthalic anhydride;

[0076] 0.5 parts of 2,4,6-tris(dimethylaminomethyl)phenol;

[0077] Among them, the flexible curing agent and the rigid curing agent undergo differential migration under the action of centrifugal force (D400 diffuses slowly, the anhydride diffuses quickly, and the diffusion rate is 1:8-10), forming a concentration gradient along the radial direction.

[0078] At the same time, polyetheramine D400 acts as a flexible curing agent in the inner layer of the epoxy resin matrix to make its cross-linking degree 50%. The reaction formula is as follows:

[0079] R-NH2+CH2-CH(O)CH2-→R-NH-CH2-CH(OH)-CH2-;

[0080] R-NH-CH2-CH(OH)-CH2-+CH2-CH(O)CH2-→RN(CH2-CH(OH)-CH2-)2;

[0081] R represents the polyether segment of polyetheramine;

[0082] Each primary amino group (-NH2) of polyetheramine D400 can open an epoxy group to generate a secondary amine and a hydroxyl group. The generated secondary amine (-NH-) can continue to react with another epoxy group to form a tertiary amine and a new hydroxyl group. The hydroxyl group (-OH) generated in the reaction can catalyze the ring opening of the epoxy group and accelerate curing.

[0083] Methyltetrahydrophthalic anhydride (MeTHPA) acts as a rigid curing agent on the outer layer of the epoxy resin matrix, making its cross-linking rate reach 85%;

[0084] 2,4,6-Tris(dimethylaminomethyl)phenol (DMP-30) acts as a accelerator on the entire epoxy resin matrix to promote the reaction between epoxy resin and methyltetrahydrophthalic anhydride. The specific reaction formula is as follows:

[0085] DMP-30+R-CO-O-CO-R→R-COO - +DMP-30-H + ;

[0086] R-COOH+CH2-CH(O)CH2-→R-COO-CH2-CH(OH)-CH2-;

[0087] R-COO-CH2-CH(OH)-CH2-+MeTHPA→cross-linked ester bond network;

[0088] R is methyltetrahydrophenyl;

[0089] DMP-30 first reacts with anhydride to generate carboxylate anions, which then attack epoxy groups to form ester bonds (—COO—) and hydroxyl groups (—OH). The generated hydroxyl groups can catalyze the remaining anhydride or epoxy groups to continue reacting, ultimately forming a cross-linked network through chain growth.

[0090] DMP-30-N+epoxy→DMP-30-N + -CH2-CH(O - )-R ;

[0091] The tertiary amine group (N) of DMP-30 directly catalyzes the ring opening of the epoxy group. The oxygen anion after the ring opening can continue to react with anhydride or another epoxy group to form an ether bond or an ester bond.

[0092] Among them, the density of epoxy-containing fluorosilicone POSS is 1.8-2.0 g / cm 3 , the molecular structure is:

[0093] ;

[0094] Where R is a perfluoroalkyl group -C2H4-C n F 2n+1 , n is any integer between 5 and 8.

[0095] The epoxy groups of epoxy-containing fluorosilicone POSS can undergo ring-opening reaction with amine / anhydride curing agents to form a covalent bond network. Since the cage structure of epoxy-containing fluorosilicone POSS has large steric hindrance when moving, the sedimentation rate is lower than that of the rigid activator. After centrifugal sedimentation, it is mainly distributed in the transition area of ​​the inner and outer layers. During segmented curing: the epoxy-containing fluorosilicone POSS located in the transition area migrates and undergoes ring-opening reaction at the same time, but since the flexible curing agent mainly distributed in the inner layer has low reaction activity, the epoxy group ring-opening rate of epoxy-containing fluorosilicone POSS is slow, and more unreacted groups are retained. Therefore, it preferentially undergoes ring-opening reaction with the rigid curing agent in the outer layer. However, the rigid curing agent that is mainly enriched in the outer layer through centrifugal sedimentation in the early stage promotes the migration of epoxy-containing fluorosilicone POSS to the outer layer, so that the content of epoxy-containing fluorosilicone POSS is distributed along the radial gradient, and the fluorine content of the outer layer is increased, thereby improving the surface hydrophobicity of the material. At the same time, the epoxy group of epoxy-containing fluorosilicone POSS forms a Si-OC cage structure after ring opening, which can form hydrogen bonds or siloxane bonds with the hydroxyl group or silane coupling agent in the resin, chemically anchoring the epoxy-containing fluorosilicone POSS, reducing interface defects, reducing the internal stress of the material, and further enhancing the bonding strength between the inner and outer layers.

[0096] Another aspect of this embodiment provides a method for preparing a fluorine-containing polymer modified epoxy resin composite insulator core rod, comprising the following steps:

[0097] ① Place bisphenol A epoxy resin, trifunctional epoxy resin and bisphenol F epoxy resin in a reaction kettle in proportion, stir at 60°C and 300 rpm, pre-mix for 20 minutes, add silane coupling agent, and continue stirring for 10-15 minutes to obtain a uniformly mixed matrix resin;

[0098] ②Polyetheramine D400 and methyltetrahydrophthalic anhydride were mixed at 50°C and a stirring rate of 200 rpm for 15 minutes, and then DMP-30 accelerator was added and stirred at 40°C for 5 minutes to obtain a curing agent system;

[0099] ③Add corresponding weight fractions of nano-SiO2 and micron-SiC into the matrix resin one by one, and disperse them at 40kHz ultrasonic speed for 30min;

[0100] ④ Add the corresponding weight fraction of fluorinated carbon nanotubes and epoxy-containing fluorosilicon POSS, use a high-speed shear emulsifier at 5000 rpm, mix for 15 minutes, slowly pour the curing agent system, control the temperature ≤40°C, stir at 400 rpm, mix for 10 minutes, and then vacuum degas (-0.1 MPa, 15 minutes) to obtain a homogeneous epoxy resin matrix;

[0101] ⑤ Arrange glass fibers of corresponding weight fractions in a unidirectional manner and place them in a glue tank. Inject a homogeneous epoxy resin matrix into the mold, centrifuge at 800 rpm for 10 minutes, immediately heat and cure in sections, and extrude and pultrude to obtain a cylindrical core rod.

[0102] The specific process of segmented heating and curing is as follows:

[0103] Phase 1: 80°C / 2h. Due to the high activity of the amine curing agent and the hindering effect of the filler in the outer layer, the polyetheramine D400 inner layer initiates a preliminary crosslinking network, while the outer layer still maintains a low degree of crosslinking. This differentiated curing degree avoids internal stress caused by sudden high crosslinking shrinkage;

[0104] The second stage: 120℃ / 3h, the fluorosilicone POSS part in the transition zone forms an organic-inorganic hybrid network with the epoxy group of the epoxy resin matrix, significantly improving the crosslinking density and heat resistance of the material. At the same time, the difference in the degree of curing of the inner and outer layers is reduced, and the overall material tends to be uniform.

[0105] The third stage: 160℃ / 4h. The outer layer of methyltetrahydrophthalic anhydride reacts completely at this temperature, forming a rigid structure with high cross-linking density on the surface of the core rod, firmly locking the SiC filler and F-CNTs on the surface, greatly improving the surface hardness and wear resistance. At the same time, the epoxy-containing fluorosilicon POSS migrates to the surface due to the chemical anchoring produced by the reaction with methyltetrahydrophthalic anhydride and the surface enrichment effect of fluorine atoms, enhancing the hydrophobicity of the core rod surface.

[0106] Traction control: The initial speed is 0.06 m / min, gradually increasing to 0.5 m / min. In the first stage, the speed is low to reduce resin loss and fiber disturbance; in the second stage, the speed is medium to ensure sufficient curing time; in the third stage, the speed is increased to enhance production efficiency while preventing overheating of the product;

[0107] ⑥ After being kept at 160℃ for 2 hours and then gradually cooled (10℃ / h) to room temperature, the internal stress is eliminated to obtain the composite insulator core rod.

[0108] In order to further understand the present invention, the fluorine-containing polymer modified epoxy resin composite insulator core rod provided by the present invention is described below with reference to examples. The protection scope of the present invention is not limited by the following examples.

[0109] Experimental Example 1

[0110] ① Place 65 parts of bisphenol A epoxy resin, 10 parts of triglycidyl p-aminophenol, and 25 parts of bisphenol F epoxy resin in a reactor, stir at 60°C and 300 rpm, pre-mix for 20 minutes, add 3 parts of γ-aminopropyltriethoxysilane, and continue stirring for 10-15 minutes to obtain a uniformly mixed matrix resin;

[0111] ② 30 parts of polyetheramine D400 and 45 parts of methyltetrahydrophthalic anhydride were mixed at 50°C and a stirring rate of 200 rpm for 15 minutes, followed by the addition of 0.5 parts of DMP-30 accelerator and stirring at 40°C for 5 minutes to obtain a curing agent system;

[0112] ③ Add 5 parts of nano-SiO2 and 15 parts of micron-SiC into the matrix resin successively, and disperse them by ultrasonic 40kHz for 30 minutes;

[0113] ④ Add 1.5 parts of fluorinated carbon nanotubes and 5 parts of epoxy-containing fluorosilicone POSS, use a high-speed shear emulsifier at 5000 rpm, mix for 15 minutes, slowly pour the curing agent system, control the temperature ≤40°C, stir at 400 rpm, mix for 10 minutes, and vacuum degas (-0.1 MPa, 15 minutes) to obtain a homogeneous epoxy resin matrix;

[0114] It contains epoxy fluorosilicon POSS, and the R group in the molecular structure is perfluoroalkyl -C2H4-C5F 11 ;

[0115] ⑤ Arrange glass fibers of corresponding weight fractions in a unidirectional manner and place them in a glue tank. Inject a homogeneous epoxy resin matrix into the mold, centrifuge at 800 rpm for 10 minutes, and immediately cure by stepwise heating at 80°C / 2h, 120°C / 3h, and 160°C / 4h. Then, pultrusion molding is performed to obtain a cylindrical core rod.

[0116] ⑥ After being kept at 160℃ for 2 hours and slowly cooled (10℃ / h) to room temperature, the internal stress is eliminated to obtain the composite insulator core rod.

[0117] Experimental Example 2

[0118] ① Place 60 parts of bisphenol A epoxy resin, 15 parts of tetraglycidyl diaminodiphenylmethane, and 25 parts of bisphenol F epoxy resin in a reactor, stir at 60°C and 300 rpm, pre-mix for 20 minutes, add 3 parts of γ-glycidyloxypropyltrimethoxysilane, and continue stirring for 10-15 minutes to obtain a uniformly mixed matrix resin;

[0119] ② 30 parts of polyetheramine D400 and 45 parts of methyltetrahydrophthalic anhydride were mixed at 50°C and a stirring rate of 200 rpm for 15 minutes, followed by the addition of 0.5 parts of DMP-30 accelerator and stirring at 40°C for 5 minutes to obtain a curing agent system;

[0120] ③ Add 5 parts of nano-SiO2 and 15 parts of micron-SiC into the matrix resin successively, and disperse them by ultrasonic 40kHz for 30 minutes;

[0121] ④ Add 1.5 parts of fluorinated carbon nanotubes and 5 parts of epoxy-containing fluorosilicone POSS, use a high-speed shear emulsifier at 5000 rpm, mix for 15 minutes, slowly pour the curing agent system, control the temperature ≤40°C, stir at 400 rpm, mix for 10 minutes, and then vacuum degas (-0.1 MPa, 15 minutes) to obtain a homogeneous epoxy resin matrix;

[0122] It contains epoxy fluorosilicon POSS, and the R group in the molecular structure is perfluoroalkyl -C2H4-C8F 17 ;

[0123] ⑤ Arrange glass fibers of corresponding weight fractions in a unidirectional manner and place them in a glue tank. Inject a homogeneous epoxy resin matrix into the mold, centrifuge at 800 rpm for 12 minutes, and immediately cure by stepwise heating at 80°C / 2 hours, 120°C / 3 hours, and 160°C / 4 hours. Then, pultrusion molding is performed to obtain a cylindrical core rod.

[0124] ⑥ After being kept at 160℃ for 2 hours and slowly cooled (10℃ / h) to room temperature, the internal stress is eliminated to obtain the composite insulator core rod.

[0125] Comparative Example 1

[0126] The commercially available fluorine-containing epoxy resin composite insulator core rod is manufactured by Yangzhou Suruida Electrical Technology Co., Ltd. and is available in the FR4 epoxy rod series.

[0127] Comparative Example 2

[0128] The common composite insulator core rods on the market are manufactured by Baoding Ditai Electric Power Equipment Manufacturing Co., Ltd. The model is vacuum injection composite insulator core rod (common type).

[0129] Test example:

[0130] The composite insulator core rods prepared in Experimental Examples 1-2 and the insulator core rods in Comparative Examples 1 and 2 were subjected to tensile strength tests using a universal material testing machine according to the test standard GB / T 19519-2014. The test results are recorded in Table 1.

[0131] According to the test standard ASTM D2344, the composite insulator core rods prepared in Experimental Examples 1-2 and the insulator core rods of Comparative Examples 1 and 2 were tested for interfacial shear strength. The test results are recorded in Table 1.

[0132] The wear resistance of the composite insulator core rods prepared in Experimental Examples 1-2 and the insulator core rods of Comparative Examples 1 and 2 was tested according to the Taber wear test (100 times). The test results are recorded in Table 1.

[0133] According to IEC 60587 (1 A / 12 h), the composite insulator core rods prepared in Experimental Examples 1-2 and the insulator core rods of Comparative Examples 1 and 2 were subjected to tracking tests. The test results are recorded in Table 1.

[0134] The perfluorinated compound content was analyzed by GC-MS, and the environmental protection test was conducted on the composite insulator core rods prepared in Experimental Examples 1-2 and the insulator core rods of Comparative Examples 1 and 2. The test results are recorded in Table 1.

[0135] Using a contact angle meter, contact angle tests were conducted on the composite insulator core rods prepared in Experimental Examples 1-2 and the insulator core rods of Comparative Examples 1 and 2 under a standard environment (temperature 23±2°C, humidity 50±5%). The test results are recorded in Table 1.

[0136] Table 1 Statistical table of experimental and comparative test data.

[0137]

[0138] In summary, the present invention provides a fluoropolymer-modified epoxy resin composite insulator core rod and a manufacturing method thereof. By designing fillers of different sizes of nano-SiO2 and micron-SiC, the difference in particle sedimentation rate during centrifugation causes the inner layer of SiO2 and the outer layer of SiC to form a density gradient in the radial direction, so that the epoxy-containing fluorosilicon POSS is "squeezed" to the middle transition zone. At the same time, by combining with the epoxy resin and through the gradient distribution of the filler, the hardness of the outer layer of the core rod is increased while the toughness of the inner layer is maintained, forming a "tough inside and hard outside" structure, which significantly improves the tensile strength and interfacial shear strength of the insulator core rod.

[0139] Moreover, through centrifugal action and the difference in diffusion rates between the rigid curing agent and the flexible curing agent in the resin, the rigid curing agent is concentrated in the outer layer, while the flexible curing agent is distributed in the inner layer. Through curing agent diffusion control and temperature gradient curing, a spontaneous cross-linking gradient is achieved in the single layer of resin, avoiding interface defects in the multi-layer stacking process and reducing stress in the core rod.

[0140] Finally, the epoxy-containing fluorosilicone POSS is "squeezed" into the middle transition zone by the filler during centrifugation. During solidification, the chemical anchoring produced by the reaction with methyltetrahydrophthalic anhydride and the surface enrichment effect of fluorine atoms migrate to the outer layer and cooperate with the F-CNTs settled to the outer layer to form a superhydrophobic surface. At the same time, the fluorine content of the material is reduced by gradient fluorine content, thereby improving environmental protection.

[0141] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A fluorine-containing polymer modified epoxy resin composite insulator core rod, characterized in that: By weight percentage, including: Glass fiber 70% to 80%; Epoxy resin matrix 20% to 30%; The epoxy resin matrix includes the following raw materials in parts by weight: 100 parts of base resin; 75.5 parts of curing agent; 1.5 parts of fluorinated carbon nanotubes; Contains 5 parts of epoxy fluorosilicone POSS; 5 parts of nano-SiO2; 15 parts of micron SiC; 3 parts of silane coupling agent; Among them, the density of epoxy-containing fluorosilicone POSS is 1.8-2.0 g / cm 3 , the molecular structure is: ； Where R is a perfluoroalkyl group -C2H4-C n F 2n+1 , n is any integer between 5 and 8.

2. The fluoropolymer modified epoxy resin composite insulator core rod according to claim 1, characterized in that: The fluorinated carbon nanotubes contain 30% to 40% fluorine and have a density of 1.8 to 2.0 g / cm 3 The matrix resin density is 1.1 to 1.2 g / cm 3 .

3. The fluoropolymer modified epoxy resin composite insulator core rod according to claim 1, characterized in that: The nano-SiO2 is a spherical particle with a diameter of 10-15nm, and the micron SiC is a spherical particle with a diameter of 50-60um.

4. The fluoropolymer modified epoxy resin composite insulator core rod according to claim 1, characterized in that: The silane coupling agent is one or more of γ-aminopropyltriethoxysilane, N-β-aminoethyl-γ-aminopropyltrimethoxysilane, and γ-glycidyloxypropyltrimethoxysilane.

5. The fluoropolymer modified epoxy resin composite insulator core rod according to claim 1, characterized in that: The base resin comprises the following raw materials in parts by weight: 55-65 parts of bisphenol A epoxy resin; 10-15 parts of trifunctional epoxy resin; 20-25 parts of bisphenol F epoxy resin.

6. The fluoropolymer modified epoxy resin composite insulator core rod according to claim 5, characterized in that: The trifunctional epoxy resin is one or more of triglycidyl p-aminophenol and tetraglycidyl diaminodiphenylmethane.

7. The fluoropolymer modified epoxy resin composite insulator core rod according to claim 1, characterized in that: The curing agent comprises the following raw materials in parts by weight: 30 parts of polyetheramine D400; 45 parts of methyltetrahydrophthalic anhydride; 0.5 parts of 2,4,6-tris(dimethylaminomethyl)phenol.

8. A method for manufacturing a fluoropolymer-modified epoxy resin composite insulator core rod, comprising preparing the fluoropolymer-modified epoxy resin composite insulator core rod according to any one of claims 1 to 7, characterized in that: The following steps are involved: ① Place bisphenol A epoxy resin, trifunctional epoxy resin and bisphenol F epoxy resin in a reaction kettle in proportion and mix them to obtain a uniformly mixed matrix resin; ② After mixing polyetheramine D400 and methyltetrahydrophthalic anhydride, add 2,4,6-tris(dimethylaminomethyl)phenol and mix again to obtain a curing agent system; ③ Add corresponding weight fractions of nano-SiO2 and micron-SiC to the matrix resin one by one, disperse them evenly by ultrasonication, add corresponding weight fractions of fluorinated carbon nanotubes and epoxy-containing fluorosilicon POSS, emulsify them using a high-speed shear emulsifier, slowly pour in the curing agent system, mix them evenly, and vacuum degas to obtain a homogeneous epoxy resin matrix; ④ Arrange glass fibers of corresponding weight fractions in a unidirectional manner and place them in a glue tank. After injecting a homogeneous epoxy resin matrix into a mold, centrifuge at 800 rpm for 10 to 15 minutes, immediately perform segmented heating and curing, and pultrusion to obtain a cylindrical core rod. The staged heating curing includes: the first stage is 80°C constant temperature for 2 hours; the second stage is 120°C constant temperature for 3 hours; the third stage is 160°C constant temperature for 4 hours; ⑤ After being kept at 160℃ for 2 hours, the temperature was cooled to room temperature at a cooling rate of 10℃ / h to obtain a composite insulator core rod.

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