Fluoropolymer-modified epoxy resin composite insulator core rod and method of making same

Abstract

The application provides a fluorine-containing polymer modified epoxy resin composite insulator core rod and a manufacturing method thereof, which comprises glass fibers, a matrix resin, a curing agent, fluorinated carbon nanotubes, epoxy group-containing fluorosilicon POSS, nano SiO2, micro SiC and a silane coupling agent. The application forms a density gradient for the fillers through centrifugation by designing fillers with different sizes, cooperates with the continuous gradient structure spontaneously formed in the single-layer resin, avoids interface mutation, makes the material tough inside and rigid outside, and simultaneously, the epoxy group-containing fluorosilicon POSS is "extruded" to the middle transition zone by the fillers during centrifugation, and migrates to the outer layer by chemical anchoring and the surface enrichment effect of fluorine atoms during solidification, so that a gradient fluorine-containing structure is formed, and the outer layer is realized to be super-hydrophobic by 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] Technical problems solved

[0008] In view of the deficiencies of the prior art, the present application provides a fluorine-containing polymer modified epoxy resin composite insulator core rod and a manufacturing method thereof to solve the problems raised in the background art.

[0009] Technical solutions

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

[0011] 70% to 80% of glass fibers;

[0012] 20% to 30% of an epoxy resin matrix;

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

[0014] 100 parts of a base resin;

[0015] 75.5 parts of a curing agent;

[0016] 1.5 parts of carbon fluoride nanotubes;

[0017] 5 parts of epoxy group-containing fluorosilicon POSS;

[0018] 5 parts of nano-SiO2;

[0019] 15 parts of micro-SiC;

[0020] 3 parts of a silane coupling agent.

[0021] As a further preferred, the carbon fluoride nanotubes have a fluorine content of 30% to 40% and a density of 1.8 to 2.0 g / cm 3 , and the base resin has a density of 1.1 to 1.2 g / cm 3 .

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

[0023] As a further preferred, the epoxy group-containing fluorosilicon POSS has a density of 1.8 to 2.0 g / cm 3 , and a molecular structure formula is:

[0024] ;

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

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

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

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

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

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

[0031] As a further preference, the trifunctional epoxy resin is one or more of trisglycidyl-p-aminophenol, tetraglycidyl-diaminodiphenylmethane.

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

[0033] polyetheramine D400 30 parts;

[0034] methyltetrahydrophthalic anhydride 45 parts;

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

[0036] A fluoropolymer-modified epoxy resin composite insulator core rod manufacturing method, which prepares the above-mentioned composite insulator core rod, comprises the following steps:

[0037] ①The bisphenol A type epoxy resin, trifunctional epoxy resin and bisphenol F type epoxy resin are placed in a reaction kettle in proportion, mixed, and a uniformly mixed base resin is obtained;

[0038] ②The polyetheramine D400 and methyltetrahydrophthalic anhydride are mixed uniformly, then 2,4,6-tris(dimethylaminomethyl)phenol is added and mixed again, and a curing agent system is obtained;

[0039] ③The corresponding weight fraction of nano-SiO2 and micron-SiC are added to the base resin in sequence, ultrasonically dispersed uniformly, and the corresponding weight fraction of carbon fluoride nanotubes and epoxy-containing fluorosilicon POSS is added, emulsified by a high-speed shearing emulsifier, and the curing agent system is slowly poured in, mixed uniformly and vacuum degassed, and a homogeneous epoxy resin matrix is obtained;

[0040] ④The corresponding weight fraction of glass fibers is arranged in one direction and placed in a glue tank, the homogeneous epoxy resin matrix is injected into a mold, centrifuged at 800 rpm for 10-15 min, immediately cured by stepwise heating, and a columnar core rod is obtained by pultrusion molding.

[0041] Wherein, the segmented heating curing comprises: a first stage of 80 DEG C constant temperature for 2h; a second stage of 120 DEG C constant temperature for 3h; and a third stage of 160 DEG C constant temperature for 4h.

[0042] 5. After 2 hours of 160 DEG C heat preservation, and gradient cooling (10 DEG C / h) to room temperature, internal stress is eliminated, and the composite insulator core rod is obtained.

[0043] (Three) beneficial effects

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

[0045] The application forms a density gradient along the radial direction by the difference in particle sedimentation rate of the inner layer SiO2 and the outer layer SiC during centrifugation, and the epoxy group-containing fluorosilicon POSS is "extruded" to the middle transition zone, and the hardness of the outer layer of the core rod is improved while the toughness of the inner layer is maintained by the gradient distribution of the fillers, forming an inner toughness and outer rigidity structure, which is suitable for the complex working conditions of extra-high voltage insulators.

[0046] Moreover, by the difference in diffusion rate of the rigid curing agent and the flexible curing agent in the resin through centrifugation, the rigid curing agent is concentrated in the outer layer, and the flexible curing agent is distributed in the inner layer, and the self-crosslinking gradient in the single-layer resin is realized by the diffusion control of the curing agent and the temperature gradient curing, so that a continuous gradient structure is formed, the interface mutation is avoided, and the interface defects of the multi-layer stacking process are avoided.

[0047] Finally, the epoxy group-containing fluorosilicon POSS is "extruded" to the middle transition zone by the fillers during centrifugation, and the chemical anchoring produced by the reaction of the epoxy group-containing fluorosilicon POSS and methyltetrahydrophthalic anhydride and the surface enrichment effect of fluorine atoms migrate to the outer layer, forming a gradient fluorine, and cooperating with the F-CNTs settled in the outer layer to enhance the hydrophobic property of the surface of the core rod, the fluorine content of the surface layer is less than 8%, and the subsequent migration and loss of fluorine is reduced by the chemical anchoring, so that low-fluorine modification is realized. BRIEF DESCRIPTION OF DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the application, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

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

[0050] In the present application, unless otherwise explicitly specified and limited, a first feature is "on" or "under" a second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature is "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only means that the first feature is horizontally higher than the second feature. The first feature is "under", "below" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or only means that the first feature is horizontally lower than the second feature.

[0051] The following disclosure provides many different embodiments, or examples, for implementing different structures of the present application. For the purpose of simplification, the components and arrangements of specific examples are described in the following. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeatedly refer to numbers and / or letters in different examples, and such repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or arrangements discussed. In addition, the present application provides various specific examples of processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.

[0052] In one aspect of the present application, a fluorine-containing polymer modified epoxy resin composite insulator core rod is provided, which comprises, by weight percentage:

[0053] Glass fiber 70% to 80%;

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

[0055] The epoxy resin matrix comprises, by weight parts, the following raw materials:

[0056] Matrix resin 100 parts;

[0057] Curing agent 75.5 parts;

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

[0059] Epoxy-containing fluorosilicon POSS 5 parts;

[0060] Nano-SiO2 5 parts;

[0061] Micro-SiC 15 parts;

[0062] Silane coupling agent 3 parts;

[0063] Among them, F-CNTs, fluorine content 30% to 40%, density 1.8 to 2.0 g / cm 3, higher than the resin density 1.1-1.2 g / cm 3 , by centrifugation to make F-CNTs rich in the outer layer of epoxy resin matrix, improve the hydrophobicity and wear resistance of the outer layer of epoxy resin matrix.

[0064] Wherein, nano-SiO2 is a spherical particle with a diameter of 10-15 nm, and micron-SiC is a spherical particle with a diameter of 50-60 um. During centrifugation, nano-SiO2 has a slow sedimentation rate and is concentrated in the inner layer, and micron-SiC has a fast sedimentation rate and is concentrated 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 fluorosilicon POSS is "extruded" to the middle transition zone, combined with the epoxy resin to improve the bonding strength of the inner and outer layers.

[0065] Wherein, the silane coupling agent is one or more of γ-aminopropyl triethoxysilane, N-β-aminoethyl-γ-aminopropyl trimethoxysilane, and γ-glycidyl ether propyl trimethoxysilane, used to improve the bonding strength of the epoxy resin matrix and glass fibers.

[0066] Wherein, the base resin includes the following raw materials in parts by weight:

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

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

[0069] Bisphenol F type epoxy resin 20-25 parts;

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

[0071] Trifunctional epoxy resin, to improve the crosslinking density of the outer layer. In this embodiment, the trifunctional epoxy resin is one or more of trisglycidyl p-aminophenol and tetraglycidyl diaminodiphenylmethane, selected from Shanghai Resin Factory, model 680 series, with an epoxy value of 0.85-1.0, to give the epoxy resin matrix higher crosslinking density and more excellent heat resistance, mechanical strength and chemical stability.

[0072] Bisphenol F type epoxy resin, to reduce the overall viscosity and improve the flowability and wettability of the resin system. In this embodiment, the bisphenol F type epoxy resin is selected from Balin Petrochemical, model CYDEF-200, with an epoxy equivalent weight of 160-180 g / eq, to improve the reactivity.

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

[0074] Polyetheramine D400 30 parts;

[0075] Methyltetrahydrophthalic anhydride 45 parts;

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

[0077] Among them, the flexible curing agent and the rigid curing agent are differentially migrated under the action of centrifugal force (D400 diffusion rate is slow, anhydride diffuses fast, and the diffusion rate is 1:8-10), and a concentration gradient is formed along the radial direction.

[0078] At the same time, polyetheramine D400 as a flexible curing agent, acts on the inner layer of the epoxy resin matrix, so that the crosslinking degree is 50%, and 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-→R-N(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, and the hydroxyl group (-OH) generated in the reaction can catalyze the ring opening of the epoxy group to accelerate the curing.

[0083] Methyltetrahydrophthalic anhydride (MeTHPA) as a rigid curing agent, acts on the outer layer of the epoxy resin matrix, so that the crosslinking rate reaches 85%;

[0084] 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30) as an accelerator acts on the entire epoxy resin matrix to promote the reaction of epoxy resin and methyltetrahydrophthalic anhydride, and 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→crosslinked ester bond network ;

[0088] R is methyltetrahydrophthalyl;

[0089] DMP-30 first reacts with anhydride to form carboxylate anion, which attacks the epoxy group to form ester bond (—COO—) and hydroxyl group (—OH). The generated hydroxyl group can catalyze the remaining anhydride or epoxy group to continue to react, and finally form a crosslinked network through chain extension.

[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, and the oxygen anion after ring opening can continue to react with anhydride or another epoxy group to form ether bond or ester bond.

[0092] The density of the epoxy-containing fluorosilicon POSS is 1.8-2.0 g / cm 3 , and the molecular structural formula is:

[0093] ;

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

[0095] The epoxy group of the epoxy-containing fluorosilicon POSS can undergo ring-opening reaction with amine / anhydride curing agent to form a covalent bond network. Since the cage structure of the epoxy-containing fluorosilicon POSS has large steric hindrance when moving, the sedimentation rate is lower than that of the rigid activator. After centrifugal sedimentation, the epoxy-containing fluorosilicon POSS is mainly distributed in the transition region of the inner and outer layers. During segmented curing, the epoxy-containing fluorosilicon POSS in the transition region migrates while undergoing ring-opening reaction. However, since the flexible curing agent mainly distributes in the inner layer and has low reactivity, the ring-opening rate of the epoxy group of the epoxy-containing fluorosilicon POSS is slow, and more unreacted groups are retained, so the epoxy-containing fluorosilicon POSS preferentially undergoes ring-opening reaction with the rigid curing agent in the outer layer. However, the rigid curing agent mainly concentrates in the outer layer through centrifugal sedimentation in the early stage, which promotes the migration of the epoxy-containing fluorosilicon POSS to the outer layer, so that the content of the epoxy-containing fluorosilicon POSS is distributed in a radial gradient, and the fluorine content in the outer layer is increased, thereby improving the hydrophobicity of the material surface. In addition, the Si-O-C cage structure formed after the ring-opening of the epoxy group of the epoxy-containing fluorosilicon POSS can form hydrogen bond or siloxane bond with the hydroxyl group or silane coupling agent in the resin, thereby chemically anchoring the epoxy-containing fluorosilicon POSS, reducing the interface defects and internal stress of the material, and further enhancing the bonding strength between the inner layer and the outer layer.

[0096] In another aspect, the embodiment also provides a preparation method of a fluorine-containing polymer modified epoxy resin composite insulator core rod, which comprises the following steps:

[0097] ①The bisphenol A type epoxy resin, trifunctional epoxy resin and bisphenol F type epoxy resin are placed in a reaction kettle in proportion, 60℃, stirring rate 300 rpm, pre-mixed for 20 min, then silane coupling agent is added, and stirring is continued for 10-15 min to obtain a uniformly mixed matrix resin;

[0098] ②Polyetheramine D400 and methyltetrahydrophthalic anhydride are mixed at 50℃, stirring rate 200 rpm, for 15 min, then DMP-30 accelerator is added and stirred at 40℃ for 5 min to obtain a curing agent system;

[0099] ③Nanoscale SiO2 and microscale SiC in corresponding weight fractions are added to the matrix resin in sequence and dispersed by ultrasonic waves at 40 kHz for 30 min;

[0100] ④Corresponding weight fractions of fluorinated carbon nanotubes and epoxy group-containing fluorosilicon POSS are added and mixed for 15 min using a high-speed shearing emulsifier at 5000 rpm, then the curing agent system is slowly poured in while controlling the temperature to be ≤40℃ and stirring at a rate of 400 rpm for 10 min, followed by vacuum degassing (-0.1 MPa, 15 min) to obtain a homogeneous epoxy resin matrix;

[0101] ⑤Glass fibers in corresponding weight fractions are arranged in a single direction in a glue tank, and the homogeneous epoxy resin matrix is injected into a mold and centrifuged at 800 rpm for 10 min, immediately followed by curing through staged heating and extrusion-pultrusion forming to obtain a columnar core rod;

[0102] The staged heating and curing process is as follows:

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

[0104] Second stage: 120℃ / 3h, the fluorosilicon POSS in the transition region forms an organic-inorganic hybrid network with the epoxy groups of the epoxy resin matrix, significantly improving the crosslinking density and heat resistance of the material, while the difference in curing degree between the inner and outer layers is reduced, and the overall material tends to be uniform;

[0105] Third stage: 160℃ / 4h, the methyltetrahydrophthalic anhydride in the outer layer is completely reacted at this temperature, forming a rigid structure with high crosslinking density on the surface of the core rod, firmly locking the SiC fillers and F-CNTs in the surface layer, greatly improving the surface hardness and wear resistance. At the same time, the epoxy group-containing fluorosilicon POSS migrates to the surface layer due to chemical anchoring with methyltetrahydrophthalic anhydride and the surface enrichment effect of fluorine atoms, enhancing the hydrophobic properties of the core rod surface;

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

[0107] ⑥After 2 hours of heat preservation at 160℃, the temperature is gradually reduced to room temperature (10℃ / h) to eliminate internal stress, and the composite insulator core rod is obtained.

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

[0109] Experimental Example 1

[0110] ①Put 65 parts of bisphenol A type epoxy resin, 10 parts of trisglycidyl p-aminophenol and 25 parts of bisphenol F type epoxy resin into a reaction kettle, stir at 60℃ and 300 rpm for 20 min, then add 3 parts of γ-aminopropyl triethoxysilane, continue to stir for 10-15 min, and get a uniformly mixed matrix resin;

[0111] ②Mix 30 parts of polyetheramine D400 and 45 parts of methyltetrahydrophthalic anhydride at 50℃ and 200 rpm for 15 min, then add 0.5 parts of DMP-30 accelerator, stir at 40℃ for 5 min, and get a curing agent system;

[0112] ③Add 5 parts of nano-SiO2 and 15 parts of micron-SiC to the matrix resin one by one, and disperse for 30 min under ultrasonic wave at 40 kHz;

[0113] ④Add 1.5 parts of carbon fluoride nanotubes and 5 parts of epoxy-containing fluorosilicon POSS, mix for 15 min at 5000 rpm using a high-speed shearing emulsifier, slowly pour the curing agent system into the mixture, control the temperature ≤40℃, mix for 10 min at 400 rpm, and then vacuum degassing (-0.1 MPa, 15 min) to get a homogeneous epoxy resin matrix;

[0114] The epoxy-containing fluorosilicon POSS has a molecular structure in which R is a perfluoroalkyl-C2H4-C5F 11 ;

[0115] ⑤Arrange the corresponding weight fraction of glass fibers in one direction in a glue tank, inject the homogeneous epoxy resin matrix into a mold, and centrifuge for 10 min at 800 rpm, then immediately cure by segmental heating at 80℃ / 2h, 120℃ / 3h and 160℃ / 4h, and then extrude and draw to form a columnar core rod;

[0116] ⑥After 2 hours of heat preservation at 160℃, and slow cooling (10℃ / h) to room temperature, internal stress is eliminated, and the composite insulator core rod is obtained.

[0117] Experimental Example 2

[0118] ① Put 60 parts of bisphenol A type epoxy resin, 15 parts of tetraglycidyl diamino diphenyl methane and 25 parts of bisphenol F type epoxy resin into a reaction kettle, pre-mix at 60℃ for 20 min at a stirring rate of 300 rpm, add 3 parts of γ-glycidyl ether oxypropyl trimethoxysilane, and continue to stir for 10-15 min to obtain a uniformly mixed matrix resin;

[0119] ② Mix 30 parts of polyetheramine D400 and 45 parts of methyltetrahydrophthalic anhydride at 50℃ for 15 min at a stirring rate of 200 rpm, then add 0.5 parts of DMP-30 accelerator, and stir at 40℃ for 5 min to obtain a curing agent system;

[0120] ③ Add 5 parts of nano-SiO2 and 15 parts of micron-SiC to the matrix resin successively, and disperse for 30 min under ultrasonic waves at 40 kHz;

[0121] ④ Add 1.5 parts of carbon fluoride nanotubes and 5 parts of epoxy group-containing fluorosilicon POSS, mix for 15 min at 5000 rpm using a high-speed shearing emulsifier, slowly pour in the curing agent system while controlling the temperature to be ≤40℃, mix for 10 min at a stirring rate of 400 rpm, and then vacuum degas (-0.1 MPa for 15 min) to obtain a homogeneous epoxy resin matrix;

[0122] The epoxy group-containing fluorosilicon POSS has a molecular structure in which the R group is a perfluoroalkyl-C2H4-C8F 17 ;

[0123] ⑤ Arrange the corresponding weight fraction of glass fibers in a unidirectional manner in a glue tank, inject the homogeneous epoxy resin matrix into a mold, and centrifuge for 12 min at 800 rpm, immediately cure by segmental heating at 80℃ / 2h, 120℃ / 3h and 160℃ / 4h, and obtain a columnar core rod by extrusion molding;

[0124] ⑥After 2 hours of heat preservation at 160℃, and slow cooling (10℃ / h) to room temperature, internal stress is eliminated, and the composite insulator core rod is obtained.

[0125] Comparative Example 1

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

[0127] Comparative Example 2

[0128] The ordinary composite insulator core rod is commercially available, and the manufacturer is Baoding Daitai Electric Power Equipment Manufacturing Co., Ltd., and the type is a vacuum injection composite insulator core rod (ordinary type).

[0129] Test example:

[0130] According to the test standard GB / T 19519-2014, the tensile strength of the composite insulator core rods prepared in Experimental Examples 1-2 and the insulator core rods of Comparative Examples 1 and 2 is tested by using a universal material testing machine. The test results are recorded in Table 1.

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

[0132] According to the Taber abrasion test (100 times), 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 is tested. The test results are recorded in Table 1.

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

[0134] By GC-MS analysis of perfluorinated compound content, the environmental protection of the composite insulator core rods prepared in Experimental Examples 1-2 and the insulator core rods of Comparative Examples 1 and 2 is tested. The test results are recorded in Table 1.

[0135] Using a contact angle measuring instrument, the contact angle of the composite insulator core rods prepared in Experimental Examples 1-2 and the insulator core rods of Comparative Examples 1 and 2 is tested under standard environment (temperature 23±2℃, humidity 50±5%). The test results are recorded in Table 1.

[0136] Table 1: Test data statistics table of experimental examples and comparative examples.

[0137]

[0138] In summary, the present application provides a fluoropolymer modified epoxy resin composite insulator core rod and a manufacturing method thereof. By designing fillers of different sizes, such as nano-SiO2 and micro-SiC, the difference in particle settling rate during centrifugation causes the SiO2 in the inner layer and the SiC in the outer layer to form a density gradient along the radial direction. The epoxy group-containing fluorosilicon POSS is "extruded" to the middle transition zone, and by combining with the epoxy resin, the gradient distribution of the fillers improves the hardness of the outer layer while maintaining the toughness of the inner layer, 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, by the difference of diffusion rate between rigid and flexible curing agents 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 the curing agent diffusion control and temperature gradient curing in the single layer resin to achieve spontaneous cross-linking gradient, avoid the interface defects of multi-layer stacking process, and reduce the stress in the mandrel;

[0140] Finally, the epoxy-containing fluorosilicone POSS is "extruded" by the filler to the middle transition zone during centrifugation, and migrates to the outer layer through chemical anchoring produced by reaction with methyltetrahydrophthalic anhydride during curing and the surface enrichment effect of fluorine atoms, and cooperates with F-CNTs settled in the outer layer to form a super-hydrophobic surface, while reducing the fluorine content of the material through gradient fluorine to improve environmental friendliness.

[0141] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A method of manufacturing a fluoropolymer-modified epoxy resin composite insulator core rod, characterized by, The method comprises the following steps: ① A bisphenol A type epoxy resin, a trifunctional epoxy resin and a bisphenol F type epoxy resin are placed in a reaction kettle in proportion, 3 parts by weight of a silane coupling agent is added, mixed, and a uniformly mixed matrix resin is obtained; wherein the base resin has a density of 1.1 to 1.2 g / cm 3 ; ② Polyetheramine D400 and methyltetrahydrophthalic anhydride are mixed at 50°C and a rotation speed of 200 rpm for 15 minutes, then 2,4,6-tris(dimethylaminomethyl)phenol is added, and stirred at 40°C for 5 minutes to obtain a curing agent system; ③ To 100 parts by weight of the matrix resin obtained in step ①, 5 parts by weight of nano-SiO2 and 15 parts by weight of micro-SiC are sequentially added and uniformly dispersed by ultrasonic; then 1.5 parts by weight of carbon fluoride nanotubes and 5 parts by weight of epoxy group-containing fluorosilicon POSS are added and emulsified by using a high-speed shearing emulsifier, then slowly poured into 75.5 parts by weight of the curing agent system obtained in step ②, mixed uniformly and vacuum degassed to obtain a homogeneous epoxy resin matrix; The nano-SiO2 is spherical microparticle with diameter of 10-15nm, and the micro-SiC is spherical microparticle with diameter of 50-60um; the carbon fluoride nanotube contains 30%-40% of fluorine and has density of 1.8-2.0g / cm 3 The epoxy group-containing fluorosilicon POSS has density of 1.8-2.0g / cm 3 The molecular structural formula is: ； wherein R is perfluoroalkyl-C2H4-C n F 2n+1 n is any integer between 5 and 8; ④ Glass fibers accounting for 70% to 80% of the total mass of the core rod are unidirectionally arranged, impregnated with the epoxy resin matrix obtained in step ③, and then injected into a mold, centrifuged at 800 rpm for 10 to 15 minutes, immediately cured by staged heating, and formed into a columnar core rod by pultrusion molding; The weight of the epoxy resin matrix is 20% to 30% of the total mass of the core rod. The staged heating curing comprises: a first stage of 80°C constant temperature for 2 hours; a second stage of 120°C constant temperature for 3 hours; a third stage of 160°C constant temperature for 4 hours; ⑤ after 2 hours of 160°C heat preservation, the temperature is lowered to room temperature at a rate of 10°C / h.

2. A fluoropolymer-modified epoxy resin composite insulator core rod, characterized in that, The method is prepared by using the manufacturing method of claim 1.

3. The fluoropolymer-modified epoxy resin composite insulator core rod according to claim 2, characterized in that, The matrix resin comprises 55 to 65 parts by weight of a bisphenol A type epoxy resin, 10 to 15 parts by weight of a trifunctional epoxy resin, and 20 to 25 parts by weight of a bisphenol F type epoxy resin.

4. The fluoropolymer-modified epoxy resin composite insulator core rod according to claim 2, characterized in that, The silane coupling agent is one or more of γ-aminopropyl triethoxysilane, N-β-aminoethyl-γ-aminopropyl trimethoxysilane, and γ-glycidyl ether propyl trimethoxysilane.

5. The fluoropolymer-modified epoxy resin composite insulator core rod according to claim 2, wherein, The curing agent system comprises 30 parts by weight of polyetheramine D400, 45 parts by weight of methyltetrahydrophthalic anhydride, and 0.5 parts by weight of 2,4,6-tris(dimethylaminomethyl)phenol.

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