Braided insulation composite cable support and preparation method and application thereof

Abstract

The invention relates to the technical field of cable supports, in particular to a braided insulation composite cable support and a preparation method and application thereof. The bracket comprises a base, a stand column bracket, a rotatable mechanism and a cable trench bracket, each part is formed by weaving and curing resin compounded with inorganic filler, modified polyester fibers used for weaving are prepared by polymerizing dicarboxylated DOPO, various dibasic acids and dihydric alcohol and spinning and stretching, and the cable trench bracket is formed by weaving and curing. The surface of the fiber is treated by a silane coupling agent to enhance the interface bonding with the polyester fiber. The preparation method comprises the steps of weaving of all parts, resin impregnation, curing and assembling, by optimizing the proportion of warp and weft fibers, the weaving process and curing parameters, the stent has excellent mechanical property, flame retardance, corrosion resistance and insulativity, and the angle can be flexibly adjusted through the rotatable mechanism. The support is suitable for cable duct bank working wells, high and low voltage cable engineering and other scenes, can meet cable supporting requirements under complex working conditions, and has good application prospects.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cable support, in particular to a braided insulation composite cable support and its preparation method and application. BACKGROUND

[0002] As a key bearing structure of power transmission system, the performance of cable support directly affects the safety and operation cost of power grid. At present, the traditional cable support is mainly made of metal materials (such as angle steel, channel steel) or ordinary composite materials (such as glass fiber reinforced unsaturated polyester), but there are obvious defects: metal support is easy to be corroded in humid environment, resulting in the decrease of structural strength, and the conductivity exists safety hazard; ordinary composite material has good insulation, but its mechanical properties are insufficient, especially the bending strength and impact toughness are difficult to meet the heavy load demand, and the flame retardance and weather resistance are poor, which is easy to cause aging and cracking due to temperature change and humidity erosion in long-term use.

[0003] In addition, most of the existing supports are fixed structures, which cannot be flexibly adjusted in angle according to the cable laying demand, and have poor installation adaptability; some composite supports use simple mixed flame retardant to improve the flame retardance, which is easy to cause migration and uneven distribution of the flame retardant, resulting in unstable flame retardant effect. Therefore, it is a key to solve the bottleneck of the prior art to develop a cable support with high strength, high insulation, excellent flame retardance and corrosion resistance, and adjustable structure. SUMMARY

[0004] The purpose of the present application is to solve the problems existing in the prior art and to provide a braided insulation composite cable support and its preparation method and application.

[0005] In order to achieve the above purpose, the present application provides a braided insulation composite cable support, which comprises the following structures: a base, a column support, a rotatable mechanism and a cable trench support. The base is made of modified polyester fiber, basalt fiber and aramid fiber, which is braided and formed after the resin with inorganic fillers is compounded and solidified. The column support is made of modified polyester fiber, basalt fiber and carbon fiber, which is braided and formed after the resin with inorganic fillers is compounded and solidified. The rotatable mechanism is made of modified polyester fiber, aramid fiber and basalt fiber, which is braided and formed after the resin with inorganic fillers is compounded and solidified. The cable trench support is made of modified polyester fiber, aramid fiber and basalt fiber, which is braided and formed after the resin with inorganic fillers is compounded and solidified. The preparation method of the modified polyester fiber is as follows: I. Under the protection of nitrogen, the flame retardant DOPO and itaconic acid are added into 1,4-dioxane, the reaction vessel is sealed, the temperature is raised to 150-170℃, the reaction is carried out for 3-5h, the temperature is cooled to 0-10℃, the white solid is precipitated after cooling and crystallization for 8-12h, the filtrate is concentrated under reduced pressure, and then the product is cooled, crystallized, filtered, and dried, and the two filtered products are combined and dried under reduced pressure to obtain dicarboxylated DOPO, and the chemical reaction equation is: The product is characterized by H NMR. By dicarboxylation of DOPO, it can participate in the generation of subsequent polyester, and the flame-retardant structure is distributed in the molecular chain of polyester by chemical method, which ensures the flame-retardant stability of polyester and avoids phase separation in use. In addition, the rigid heterocyclic structure of DOPO can enhance the stability of molecular chain and improve the heat resistance of polyester. II. Terephthalic acid, isophthalic acid, dicarboxylated DOPO, ethylene glycol, octanediol and hexafluorobisphenol A are added into a reaction kettle, molecular sieves are added, nitrogen is introduced and replaced three times, and the pressure is increased to 0.2-0.3MPa. The temperature is raised to 200-220℃, and the reaction is carried out for 2-4h. Then trihydroxypropane and a catalyst are added, the pressure is restored to normal, the temperature is raised to 240-280℃, and the reaction is carried out for 4-6h. Then 1-naphthoic acid is added, and the reaction is carried out for 1-2h. The molecular sieves are separated while hot, and the obtained product is precipitated in 0-10℃ ethanol. The obtained precipitate is washed, dried, and granulated to obtain a modified polyester. The product is characterized by FTIR infrared spectrum. III. The modified polyester is added into a double-screw extruder, and after melt extrusion, it is conveyed to a spinneret through a metering pump at a speed of 10-20rpm, with a pore size of 0.2-0.35mm. The extruded stream is cooled and solidified through a ring blowing system at a wind temperature of 15-25℃ and a wind speed of 0.4-0.6m / s to obtain a primary fiber. The primary fiber is stretched through a stretching machine, and finally, it is heat set at a temperature of 175-185℃ for 1.5-2.5min to eliminate internal stress and obtain a modified polyester fiber.

[0006] Preferably, the inorganic filler refers to aluminum hydroxide, magnesium hydroxide, talc and wollastonite.

[0007] Preferably, the resin compounded with inorganic fillers refers to epoxy resin E-51, methylhexahydrophthalic anhydride, aluminum hydroxide, magnesium hydroxide, talc and wollastonite mixed in a weight ratio of 7:3:0.6:0.6:0.4:0.03.

[0008] Preferably, the aramid fiber, basalt fiber and carbon fiber are treated with silane coupling agent KH-550, and the treatment process is as follows: the aramid fiber, basalt fiber and carbon fiber are respectively unfolded, the surface impurities and oil stains are removed, then immersed in a solution containing silane coupling agent KH-550, stirred for 10-20 min, after soaking, taken out, washed with ethanol and dried to obtain the silane coupling agent solution prepared by mixing silane coupling agent KH-550, ethanol and deionized water in a weight ratio of 1:9:1.

[0009] Preferably, the molar ratio of the flame retardant DOPO and itaconic acid in I is 1:1-1.1, and the weight ratio of the flame retardant DOPO and 1,4-dioxane is 1:8-12.

[0010] Preferably, the molar ratio of terephthalic acid, isophthalic acid, dicarboxylated DOPO, ethylene glycol, octanediol, hexafluorobisphenol A and trihydroxypropane in II is 4-6:2-4:1-3:5-7:1-3:1-3:0.1-0.4.

[0011] Preferably, the total mass of terephthalic acid, isophthalic acid, dicarboxylated DOPO, ethylene glycol, octanediol, hexafluorobisphenol A and trihydroxypropane in II and the weight ratio of molecular sieve, catalyst, 1-naphthalene carboxylic acid are 1:0.05-0.15:0.03-0.07:0.01-0.03.

[0012] Preferably, the catalyst in II refers to tetrabutyl titanate.

[0013] Preferably, the terephthalic acid in II is a main binary acid monomer with symmetrical molecular structure and strong rigidity, and forms ester bond by esterification with binary alcohol to provide regular linear skeleton for polyester molecular chain, which is the core component to ensure the mechanical strength of polyester. The symmetrical structure can promote the orderly arrangement of molecular chain, improve the crystallization performance and heat resistance of polyester; isophthalic acid and terephthalic acid are structural isomers, but the molecular structure is asymmetrically distributed. The introduction can break the highly regular structure formed by terephthalic acid, appropriately reduce the crystallinity, improve the toughness and processing fluidity of polyester, avoid the brittleness problem caused by excessive crystallization, and maintain certain mechanical properties; ethylene glycol as a main binary alcohol monomer has short molecular chain and regular linear structure, and the ether bond formed after reaction with binary acid is stable, which provides the basic molecular chain length and linear structure for polyester, and is the key to ensure the basic mechanical properties and crystallinity of polyester. The low molecular weight characteristics help to improve the monomer reactivity and promote the smooth progress of polymerization reaction; octanediol is a long-chain binary alcohol containing 8 carbon methylene segments in the molecule, which can reduce the intermolecular force and improve the processing fluidity of polyester. In addition, the long-chain alkyl has strong hydrophobicity, which can reduce the hydrophilicity of polyester molecular chain, reduce water absorption, thereby improving the corrosion resistance of polyester in humid or corrosive environment, and prolonging the service life of the material; hexafluorobisphenol A contains two phenolic hydroxyl groups and two trifluoromethyl groups, and the molecular structure has rigidity and hydrophobicity. The rigid skeleton can enhance the rigidity of molecular chain, improve the heat resistance and mechanical strength of polyester, and the introduction of fluorinated groups can reduce the surface energy and water absorption of polyester, improve the corrosion resistance and insulation performance. At the same time, the steric hindrance of fluorine atom can further adjust the crystallization behavior of polyester to balance rigidity and toughness; trihydroxypropane as a branching center forms a small amount of branched or crosslinked structure between polyester molecular chains. Its role is to control the molecular weight distribution of polyester, improve the melt strength and mechanical properties, and the branched structure can inhibit the excessive crystallization of molecular chain, improve the dimensional stability of polyester, and reduce the deformation caused by crystallization shrinkage; since the molar amount of hydroxyl group is slightly larger than that of carboxyl group during the synthesis of polyester, the obtained polyester chain ends are hydroxyl-terminated. 1-naphthalene carboxylic acid as an end-capping agent contains a carboxyl group in the molecular structure, which can react with the hydroxyl group at the end of the polyester molecular chain to achieve end-capping. The rigid π-bond structure of naphthalene ring restricts the movement of molecular chain end, improves the regularity of molecular chain, and enhances the mechanical properties. At the same time, the number of terminal hydroxyl groups is reduced, and the hydrophilicity of polyester is reduced. In addition, the introduction of naphthalene ring can enhance the intermolecular force through π-π stacking effect, further improve the heat resistance and cohesive energy density of polyester.

[0014] Preferably, the parameters of the double screw extruder in III are as follows: the temperature of the first zone is 255-265℃, the temperature of the second zone is 265-275℃, the temperature of the third zone is 275-285℃, the temperature of the fourth zone is 285-295℃, the temperature of the die head is 285-295℃, and the screw rotation speed is 25-35 rpm.

[0015] Preferably, the stretching parameters of the third stretching machine in the III are as follows: the first stretching temperature is 75-85 DEG C, the stretching multiple is 2.3-2.8; the second stretching temperature is 95-105 DEG C, the stretching multiple is 1.4-1.8; the third stretching temperature is 115-125 DEG C, and the stretching multiple is 0.9-1.1.

[0016] Further, the application also provides a preparation method of the braided type insulation composite cable support, which specifically comprises the following steps: S1. Base preparation: the warp uses modified polyester fiber mixed with basalt fiber, the weft uses modified polyester fiber mixed with aramid fiber, a multi-axial warp knitting machine is used, and the base is knitted into a preform according to the shape of a base mold; the base preform is placed into the mold, a resin compounded with inorganic fillers is injected into the mold through a vacuum assisted resin transfer molding process, pressure impregnation is performed for 10-20 min, the mold is taken out, the excess resin is removed, and then curing is performed; the curing conditions are as follows: first curing at 70-80 DEG C for 1-2 h, then curing at 120-130 DEG C for 3-4 h, demolding after cooling to room temperature, polishing burrs to obtain the base; S2. Column support preparation: the warp uses carbon fiber, the weft uses modified polyester fiber mixed with basalt fiber, a two-dimensional braiding machine is selected, and the column support is knitted into a preform according to the shape of a column support mold; the column support preform is placed into the mold, a resin compounded with inorganic fillers is injected into the mold through a vacuum assisted resin transfer molding process, pressure impregnation is performed for 10-20 min, the mold is taken out, the excess resin is removed, and then curing is performed; the curing conditions are as follows: first curing at 70-80 DEG C for 1-2 h, then curing at 120-130 DEG C for 3-4 h, demolding after cooling to room temperature, polishing burrs to obtain the column support; S3. Rotatable mechanism preparation: the warp uses modified polyester fiber mixed with aramid fiber, the weft uses modified polyester fiber mixed with basalt fiber, a multi-axial warp knitting machine is used, and the rotatable mechanism is knitted into a preform according to the shape of the rotatable mechanism; the rotatable mechanism preform is placed into the mold, a resin compounded with inorganic fillers is injected into the mold through a vacuum assisted resin transfer molding process, pressure impregnation is performed for 10-20 min, the mold is taken out, the excess resin is removed, and then curing is performed; the curing conditions are as follows: first curing at 70-80 DEG C for 2-3 h, then curing at 120-130 DEG C for 3-4 h, demolding after cooling to room temperature, polishing burrs, and then installing bearings to obtain the rotatable mechanism; S4. Cable trench support preparation: warp uses modified polyester fiber mixed with aramid fiber, weft uses modified polyester fiber mixed with basalt fiber, uses multi-axial warp knitting machine, knits into shape according to the shape of the cable trench support, embeds the lock structure embedded part connected with the rotatable mechanism in the knitting process, obtains the cable trench support prefabricated part, puts the cable trench support prefabricated part into the mold, uses vacuum assisted resin transfer molding process, injects resin compounded with inorganic filler, pressure impregnation for 10-20 min, takes out the mold, removes the excess resin and the lock structure embedded part connected with the rotatable mechanism, then solidifies, the solidification conditions are: first solidify at 70-80℃ for 2-3h, then heat to 120-130℃ for 3-4h, cool to room temperature, demold, polish burrs, install the lock structure connected with the rotatable mechanism, obtain the rotatable mechanism; S5. The column support is vertically installed on the base, and then the rotatable mechanism is installed between the column support and the cable trench support, to obtain a woven insulation composite cable support.

[0017] Preferably, in the S1 warp, the weight ratio of modified polyester fiber to basalt fiber is 5-8:2-4, and in the weft, the weight ratio of modified polyester fiber to aramid fiber is 5-7:3-5, the needle pitch in the multi-axial warp knitting machine is 2-3mm, the needle density is 12-16 needles / cm, the warp tension is 10-14cN, and the weft tension is 8-12cN.

[0018] Preferably, in the S2 weft, the weight ratio of modified polyester fiber to basalt fiber is 5-7:3-5, the needle pitch in the two-dimensional warp knitting machine is 1.5-2.5mm, the needle density is 14-18 needles / cm, the warp tension is 13-17cN, the weft tension is 10-14cN, and the knitting speed is 8-12r / min.

[0019] Preferably, in the S3 warp, the weight ratio of modified polyester fiber to aramid fiber is 5-8:2-4, and in the weft, the weight ratio of modified polyester fiber to basalt fiber is 5-8:2-4, the needle pitch in the multi-axial warp knitting machine is 2-2.4mm, the needle density is 13-17 needles / cm, the warp tension is 11-15cN, and the weft tension is 9-13cN.

[0020] Preferably, in the S4 warp, the weight ratio of modified polyester fiber to aramid fiber is 5-7:3-5, and in the weft, the weight ratio of modified polyester fiber to basalt fiber is 5-7:3-5, the needle pitch in the multi-axial warp knitting machine is 2.1-2.5mm, the needle density is 13-15 needles / cm, the warp tension is 10-14cN, and the weft tension is 8-12cN.

[0021] Further, the application also provides the application of the above woven insulation composite cable support in cable pipe well, public power system cable engineering, user self-built special power facility cable engineering, high and low voltage cable engineering.

[0022] The application has the following beneficial effects: 1. The application significantly improves the comprehensive mechanical properties of the cable support through molecular design and material compounding technology. The symmetry rigid backbone of terephthalic acid and the flexibility adjustment of isophthalic acid in the modified polyester molecular chain form a balance, and the rigid heterocycle of double-carboxylated DOPO and the enhanced structure of hexafluorobisphenol A are combined to give the molecular chain excellent bending resistance and impact resistance. After the carbon fiber, aramid fiber, etc. are treated with silane coupling agent, they form a firm interfacial bond with the polyester fiber, and a three-dimensional reinforcing network is established through multi-axial weaving to make the support not only bear the heavy load of the cable, but also resist impact load during installation and use, thus meeting the structural stability requirements under complex working conditions.

[0023] 2. The application gives the cable support outstanding flame retardant and weather resistant properties. The double-carboxylated DOPO is embedded in the polyester molecular chain through covalent bond to realize the molecular-level uniform distribution of the flame retardant element, and the synergistic effect of the compounded inorganic filler is combined to form a high-efficiency flame retardant system that can effectively inhibit flame spread and reduce the release of toxic smoke. The long-chain alkyl of octanediol and the fluorinated group of hexafluorobisphenol A enhance the hydrophobicity of the material, and the dense interface structure of the fiber and the resin is combined to significantly improve the anti-aging performance of the support in humid and corrosive environments, thus prolonging the service life.

[0024] 3. The application optimizes the insulation performance and structural adaptability of the cable support. The polar groups in the modified polyester molecular chain are capped and regulated by 1-naphthalene carboxylic acid, and the non-polar structure of hexafluorobisphenol A is combined to reduce the electrical conductivity of the material and ensure excellent insulation strength. The rotatable mechanism and the multi-component modular design realize the flexible adjustment of the angle of the cable trench support through the optimization of the fiber ratio of the warp and weft and the adjustment of the weaving process, adapt to different laying path requirements, and at the same time simplify the installation process and improve the convenience of engineering application. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 H NMR spectrum of double-carboxylated DOPO prepared in Preparation Example 2 of the application; Figure 2 FTIR infrared spectrum of modified polyester prepared in Preparation Example 2 of the application; Figure 3 Structure schematic diagram of the woven insulation composite cable support produced by the application; Figure 4 Finite element analysis cloud map of the woven insulation composite cable support produced by the application.

[0026] The components include: 1. base, 2. support column, 3. rotatable mechanism, and 4. cable trench support. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0028] Raw material preparation: Pretreatment of aramid fiber, basalt fiber and carbon fiber: Aramid fiber, basalt fiber and carbon fiber are unfolded separately, surface impurities and oil stains are removed, and then they are immersed in a solution containing silane coupling agent KH-550 (silane coupling agent KH-550, ethanol and deionized water are mixed in a weight ratio of 1:9:1). With stirring, they are soaked for 10-20 minutes. After soaking, they are taken out, rinsed with ethanol, and dried for later use. Preparation of resin with compound inorganic filler: Epoxy resin E-51, methyl hexahydrophthalic anhydride aluminum hydroxide, magnesium hydroxide, talc powder and wollastonite are mixed in a weight ratio of 7:3:0.6:0.6:0.4:0.03 and stirred evenly to prepare resin with compound inorganic filler for later use.

[0029] Preparation Example 1: A specific preparation method for modified polyester, including the following steps: (1) Under nitrogen protection, 20g of flame retardant DOPO and 12.04g of itaconic acid were added to 160g of 1,4-dioxane, the reaction vessel was sealed, the temperature was raised to 150℃, the reaction was carried out for 3h, the temperature was cooled to 0℃, the crystallization was carried out for 8h, a white solid was precipitated, filtered, washed and dried, the filtrate was concentrated under reduced pressure, and then cooled, crystallized and filtered again. The two filtered products were combined and dried under reduced pressure to obtain dicarboxylated DOPO; (2) Add 50g terephthalic acid, 25g isophthalic acid, 26.05g dicarboxylated DOPO, 23.35g ethylene glycol, 11.01g octanediol and 25.30g hexafluorobisphenol A to a reaction vessel, add 8.07g molecular sieve, purge with nitrogen gas, replace three times, pressurize to 0.2MPa, heat to 200℃, react for 2h, then add 0.70g trihydroxypropane and 4.84g tetrabutyl titanate, restore to normal pressure, heat to 240℃, react for 4h, then add 1.61g 1-naphthoic acid, react for 1h, separate the molecular sieve while hot, add the obtained product to 0℃ ethanol while hot to precipitate, wash, dry and granulate the obtained precipitate to obtain modified polyester; (3) The modified polyester is added into a twin-screw extruder, and the temperature of the first zone is 255°C, the temperature of the second zone is 265°C, the temperature of the third zone is 275°C, the temperature of the fourth zone is 285°C, the temperature of the die head is 285°C, and the screw rotation speed is 25 rpm. After melting extrusion, the product is transported to the spinneret through a metering pump with a rotation speed of 10 rpm, and the pore diameter is 0.2 mm. After extrusion, the product is rapidly cooled and solidified through a ring blowing system with a wind temperature of 15°C and a wind speed of 0.4 m / s to obtain a primary fiber. The fiber is stretched through a stretching machine, and the first-stage stretching temperature is 75°C, the stretching ratio is 2.3, the second-stage stretching temperature is 95°C, the stretching ratio is 1.4, the third-stage stretching temperature is 115°C, the stretching ratio is 0.9, and finally, the fiber is subjected to tight heat setting at a temperature of 175°C for 1.5 min to eliminate internal stress, thereby obtaining the modified polyester fiber.

[0030] Preparation Example 2: A specific preparation method of the modified polyester, comprising the following steps: (1) Under nitrogen protection, 40 g of the flame retardant DOPO and 25.28 g of itaconic acid are added into 400 g of 1,4-dioxane, and the reaction container is sealed. The temperature is raised to 160°C, and the reaction is carried out for 4 h. The temperature is cooled to 5°C, and the temperature is lowered for crystallization for 10 h. White solids are precipitated, and after filtration, washing, and drying, the filtrate is concentrated under reduced pressure. After cooling, crystallization, and filtration, the products of the two filtrations are combined and dried under reduced pressure to obtain dicarboxylated DOPO. As shown in the H NMR characterization result in Figure 1 , it can be seen that there are thirteen hydrogens. According to the structural formula of dicarboxylated DOPO, except for the two active hydrogens of the carboxyl groups, there is a one-to-one correspondence. There are eight hydrogens at the position of the aromatic ring, which correspond to the eight hydrogens at the position of the aromatic ring in the molecular structure. There are five hydrogens in the high-field region, which correspond to five hydrogens of a methylene group and a methine group in the molecular structure. The product structure is correct. (2) 50 g of terephthalic acid, 30 g of isophthalic acid, 41.69 g of dicarboxylated DOPO, 22.42 g of ethylene glycol, 17.61 g of octanediol, and 40.48 g of hexafluorobisphenol A are added into a reaction kettle, 20.36 g of molecular sieves are added, nitrogen is introduced for three times, and the pressure is increased to 0.25 MPa. The temperature is raised to 210°C, and the reaction is carried out for 3 h. Then, 1.39 g of trihydroxypropane and 10.18 g of tetrabutyl titanate are added, the pressure is returned to normal, the temperature is raised to 260°C, and the reaction is carried out for 5 h. Then, 4.07 g of 1-naphthalene carboxylic acid is added, and the reaction is carried out for 1.5 h. The molecular sieves are separated while hot, and the obtained product is precipitated in 5°C ethanol. After washing and drying, the obtained precipitate is granulated to obtain the modified polyester. As shown in the FTIP infrared spectrum characterization result in Figure 2 , it can be seen that there are obvious absorption peaks of benzene ring, ester group, carboxyl group, hydroxyl group, phenolic hydroxyl group, and C-F bond in the infrared spectrum; (3) The modified polyester is added into a twin-screw extruder, and the temperature of the first zone is set to 260°C, the temperature of the second zone is set to 270°C, the temperature of the third zone is set to 280°C, the temperature of the fourth zone is set to 290°C, the temperature of the die head is set to 290°C, and the screw rotation speed is set to 30 rpm. After melting extrusion, the product is transported to a spinneret through a metering pump at a rotation speed of 15 rpm, and the pore diameter is 0.25 mm. After extrusion, the extrusion stream is rapidly cooled and solidified through a ring blowing system at a wind temperature of 20°C and a wind speed of 0.5 m / s to obtain a nascent fiber. The fiber is stretched through a stretching machine at a first stretching temperature of 80°C, a first stretching multiple of 2.6, a second stretching temperature of 100°C, a second stretching multiple of 1.6, a third stretching temperature of 120°C, and a third stretching multiple of 1.0. Finally, the fiber is treated by tight heat setting at a setting temperature of 180°C for 2 min to eliminate internal stress, thereby obtaining a modified polyester fiber.

[0031] Preparation Example 3: A specific preparation method of the modified polyester, comprising the following steps: (1) Under nitrogen protection, 60 g of the flame retardant DOPO and 39.72 g of itaconic acid are added into 720 g of 1,4-dioxane, the reaction container is sealed, and the temperature is raised to 170°C. After reaction for 5 h, the temperature is cooled to 10°C, and the temperature is lowered for crystallization for 12 h. White solids are precipitated, and after filtration, washing, and drying, the filtrate is concentrated under reduced pressure, and then cooled, crystallized, and filtered. The products of the two filtrations are combined and dried under reduced pressure to obtain dicarboxylated DOPO; (2) 50 g of terephthalic acid, 33.33 g of isophthalic acid, 52.11 g of dicarboxylated DOPO, 21.79 g of ethylene glycol, 22.02 g of octanediol, and 50.60 g of hexafluorobisphenol A are added into a reaction kettle, 34.76 g of molecular sieves are added, nitrogen is introduced for three times, and the pressure is increased to 0.3 MPa. After the temperature is raised to 220°C, reaction is performed for 4 h. Then, 1.85 g of trihydroxypropane and 16.22 g of tetrabutyl titanate are added, the pressure is returned to normal, the temperature is raised to 280°C, and reaction is performed for 6 h. Then, 6.95 g of 1-naphthoic acid is added, and reaction is performed for 2 h. The molecular sieves are separated while hot, and the obtained product is precipitated in 10°C ethanol. After washing and drying, the obtained precipitate is granulated to obtain the modified polyester; (3) The modified polyester is added into a twin-screw extruder, and the temperature of the first zone is set to 265°C, the temperature of the second zone is set to 275°C, the temperature of the third zone is set to 285°C, the temperature of the fourth zone is set to 295°C, the temperature of the die head is set to 295°C, and the screw rotation speed is set to 35 rpm. After melting extrusion, the product is transported to a spinneret through a metering pump with a rotation speed of 20 rpm, a hole diameter of 0.35 mm, and then is rapidly cooled and solidified through a circular blowing system with a wind temperature of 25°C and a wind speed of 0.6 m / s to obtain a primary fiber. The primary fiber is stretched through a stretching machine, the first-stage stretching temperature is 85°C, the stretching multiple is 2.8, the second-stage stretching temperature is 105°C, the stretching multiple is 1.8, the third-stage stretching temperature is 125°C, the stretching multiple is 1.1, and finally, the fiber is treated by tight heat setting at a setting temperature of 185°C for 2.5 min to eliminate internal stress, thereby obtaining the modified polyester fiber.

[0032] Comparative Preparation Example 1: The difference between Comparative Preparation Example 1 and Preparation Example 2 is that step (1) is omitted, and the flame retardant DOPO is mixed and extruded with the modified polyester in the original step (3) in the twin-screw extruder. The specific preparation process is as follows: the specific preparation method of the modified polyester comprises the following steps: (1) 50 g of terephthalic acid, 30 g of isophthalic acid, 22.42 g of ethylene glycol, 17.61 g of octanediol, and 40.48 g of hexafluorobisphenol A are added into a reaction kettle, 20.36 g of molecular sieves is added, nitrogen is introduced for three times, and the pressure is increased to 0.25 MPa. The temperature is increased to 210°C, and the reaction is performed for 3 h. Then, 1.39 g of trihydroxypropane and 10.18 g of tetrabutyl titanate are added, the normal pressure is restored, the temperature is increased to 260°C, and the reaction is performed for 5 h. Then, 4.07 g of 1-naphthalene carboxylic acid is added, and the reaction is performed for 1.5 h. The molecular sieves is separated while hot, and the obtained product is precipitated in 5°C ethanol while hot. The obtained precipitate is washed, dried, and granulated to obtain the modified polyester; (2) The modified polyester prepared in step (1) and 32.53 g of the flame retardant DOPO are added into a twin-screw extruder, and the temperature of the first zone is set to 260°C, the temperature of the second zone is set to 270°C, the temperature of the third zone is set to 280°C, the temperature of the fourth zone is set to 290°C, the temperature of the die head is set to 290°C, and the screw rotation speed is set to 30 rpm. After melting extrusion, the product is transported to a spinneret through a metering pump with a rotation speed of 15 rpm, a hole diameter of 0.25 mm, and then is rapidly cooled and solidified through a circular blowing system with a wind temperature of 20°C and a wind speed of 0.5 m / s to obtain a primary fiber. The primary fiber is stretched through a stretching machine, the first-stage stretching temperature is 80°C, the stretching multiple is 2.6, the second-stage stretching temperature is 100°C, the stretching multiple is 1.6, the third-stage stretching temperature is 120°C, the stretching multiple is 1.0, and finally, the fiber is treated by tight heat setting at a setting temperature of 180°C for 2 min to eliminate internal stress, thereby obtaining the modified polyester fiber.

[0033] Comparative Preparation Example 2: The difference between Comparative Preparation Example 2 and Preparation Example 2 is that isophthalic acid is not added, and the missing isophthalic acid is supplemented by p-terephthalic acid in terms of molar amount.

[0034] Comparative Preparation Example 3: The difference between Comparative Preparation Example 3 and Preparation Example 2 is that octanediol is not added, and the missing octanediol is supplemented by ethylene glycol in terms of molar amount.

[0035] Comparative Preparation Example 4: The difference between Comparative Preparation Example 4 and Preparation Example 2 is that hexafluorobisphenol A is replaced by bisphenol A.

[0036] Comparative Preparation Example 5: The difference between Comparative Preparation Example 5 and Preparation Example 2 is that trihydroxypropane is not added.

[0037] Comparative Preparation Example 6: The difference between Comparative Preparation Example 6 and Preparation Example 2 is that 1-naphthoic acid is not added.

[0038] Example 1: A specific preparation method of a braided type insulation composite cable support, comprising the following steps: S1. Base preparation: the warp uses the modified polyester fiber prepared in Preparation Example 1 and basalt fiber mixed in a weight ratio of 5:2, the weft uses the modified polyester fiber prepared in Preparation Example 1 and aramid fiber mixed in a weight ratio of 5:3, a multi-axial warp knitting machine is used, the needle distance is 2mm, the needle density is 12 needles / cm, the warp tension is 10cN, the weft tension is 8cN, the knitting speed is 10r / min, and the base is knitted into a preform according to the shape of the base mold. The base preform is placed in the mold, a resin compounded with inorganic fillers is injected by using a vacuum assisted resin transfer molding process, pressure impregnation is performed for 10min, the mold is taken out, the excess resin is removed, and then curing is performed. The curing conditions are: first curing at 70℃ for 1h, then curing at 120℃ for 3h, demolding after cooling to room temperature, polishing burrs to obtain the base; S2. Column support preparation: the warp uses carbon fiber, the weft uses the modified polyester fiber prepared in Preparation Example 1 and basalt fiber mixed in a weight ratio of 5:3, a two-dimensional braiding machine is selected, the needle distance is 1.5mm, the needle density is 14 needles / cm, the warp tension is 13cN, the weft tension is 10cN, the knitting speed is 8r / min, and the column support is knitted into a preform according to the shape of the column support mold. The column support preform is placed in the mold, a resin compounded with inorganic fillers is injected by using a vacuum assisted resin transfer molding process, pressure impregnation is performed for 10min, the mold is taken out, the excess resin is removed, and then curing is performed. The curing conditions are: first curing at 70℃ for 1h, then curing at 120℃ for 3h, demolding after cooling to room temperature, polishing burrs to obtain the column support; S3. Rotatable mechanism preparation: warp uses modified polyester fiber prepared by preparation example 1 and aramid fiber mixed by weight ratio of 5:2, weft uses modified polyester fiber prepared by preparation example 1 and basalt fiber mixed by weight ratio of 5:2, using multi-axial warp knitting machine, needle spacing 2mm, knitting density 13 needles / cm, warp tension 11cN, weft tension 9cN, knitting speed 9r / min, according to the shape of the rotatable mechanism, knitting forming, getting rotatable mechanism preform, putting the rotatable mechanism preform into the mold, using vacuum assisted resin transfer molding process, injecting resin compounded with inorganic filler, pressure impregnation for 10min, taking out the mold, removing excess resin, then curing, the curing conditions are: first curing at 70℃ for 2h, then heating to 120℃ for 3h, cooling to room temperature, demolding, polishing burrs, installing bearings, getting rotatable mechanism; S4. Cable trench support preparation: warp uses modified polyester fiber prepared by preparation example 1 and aramid fiber mixed by weight ratio of 5:3, weft uses modified polyester fiber prepared by preparation example 1 and basalt fiber mixed by weight ratio of 5:3, using multi-axial warp knitting machine, needle spacing 2.1mm, knitting density 13 needles / cm, warp tension 10cN, weft tension 8cN, knitting speed 10r / min, according to the shape of the cable trench support, knitting forming, embedding the lock structure embedded part connected with the rotatable mechanism in the knitting process, getting cable trench support preform, putting the cable trench support preform into the mold, using vacuum assisted resin transfer molding process, injecting resin compounded with inorganic filler, pressure impregnation for 10min, taking out the mold, removing excess resin and the lock structure embedded part connected with the rotatable mechanism, then curing, the curing conditions are: first curing at 70℃ for 2h, then heating to 120℃ for 3h, cooling to room temperature, demolding, polishing burrs, installing the lock structure connected with the rotatable mechanism, getting rotatable mechanism; S5. The column support is vertically installed on the base, then the rotatable mechanism is installed between the column support and the cable trench support, getting the woven type insulation composite cable support.

[0039] Example 2: A specific preparation method of a woven type insulation composite cable support, including the following steps: S1. Base preparation: warp uses modified polyester fiber prepared by preparation example 2 and basalt fiber mixed by weight ratio 7:3, weft uses modified polyester fiber prepared by preparation example 2 and aramid fiber mixed by weight ratio 6:4, using multi-axial warp knitting machine, needle spacing 2.5mm, needle density 14 needles / cm, warp tension 12cN, weft tension 10cN, knitting speed 12r / min, according to the shape of base mold, knitting forming, getting base preform, putting base preform into mold, using vacuum assisted resin transfer molding process, injecting resin compounded with inorganic filler, pressure impregnation for 15min, taking out the mold, removing excess resin, then curing, the curing conditions are: first at 75℃ for 1.5h, then at 125℃ for 3.5h, cooling to room temperature, demolding, polishing burrs, getting base; S2. Column support preparation: warp uses carbon fiber, weft uses modified polyester fiber prepared by preparation example 2 and basalt fiber mixed by weight ratio 6:4, using two-dimensional weaving machine, needle spacing 2mm, needle density 16 needles / cm, warp tension 15cN, weft tension 12cN, knitting speed 10r / min, according to the shape of column support mold, knitting forming, getting column support preform, putting column support preform into mold, using vacuum assisted resin transfer molding process, injecting resin compounded with inorganic filler, pressure impregnation for 15min, taking out the mold, removing excess resin, then curing, the curing conditions are: first at 75℃ for 1.5h, then at 125℃ for 3.5h, cooling to room temperature, demolding, polishing burrs, getting column support; S3. Rotatable mechanism preparation: warp uses modified polyester fiber prepared by preparation example 2 and aramid fiber mixed by weight ratio 7:3, weft uses modified polyester fiber prepared by preparation example 2 and basalt fiber mixed by weight ratio 7:3, using multi-axial warp knitting machine, needle spacing 2.2mm, needle density 15 needles / cm, warp tension 13cN, weft tension 11cN, knitting speed 11r / min, according to the shape of rotatable mechanism, knitting forming, getting rotatable mechanism preform, putting rotatable mechanism preform into mold, using vacuum assisted resin transfer molding process, injecting resin compounded with inorganic filler, pressure impregnation for 15min, taking out the mold, removing excess resin, then curing, the curing conditions are: first at 75℃ for 2.5h, then at 125℃ for 3.5h, cooling to room temperature, demolding, polishing burrs, installing bearing, getting rotatable mechanism; S4. Cable trench support preparation: warp uses modified polyester fiber prepared by preparation example 2 and aramid fiber mixed by weight ratio 6:4, weft uses modified polyester fiber prepared by preparation example 2 and basalt fiber mixed by weight ratio 6:4, using multi-axial warp knitting machine, needle spacing 2.3mm, knitting density 14 needles / cm, warp tension 12cN, weft tension 10cN, knitting speed 12r / min, according to the shape of cable trench support, knitting forming, embedding the lock structure embedded part connected with the rotatable mechanism in the knitting process, obtaining the cable trench support prefabricated part, placing the cable trench support prefabricated part into the mold, using vacuum assisted resin transfer molding process, injecting resin compounded with inorganic filler, pressure impregnation for 15min, taking out the mold, removing the excess resin and the lock structure embedded part connected with the rotatable mechanism, then curing, the curing conditions are: first curing at 75℃ for 2.5h, then heating to 125℃ for 3.5h, cooling to room temperature, demolding, polishing burrs, installing the lock structure connected with the rotatable mechanism, obtaining the rotatable mechanism; S5. The column support is vertically installed on the base, and then the rotatable mechanism is installed between the column support and the cable trench support, obtaining the woven type insulation composite cable support.

[0040] Example 3: A specific preparation method of a woven type insulation composite cable support, comprising the following steps: S1. Base preparation: warp uses modified polyester fiber prepared by preparation example 3 and basalt fiber mixed by weight ratio 8:4, weft uses modified polyester fiber prepared by preparation example 3 and aramid fiber mixed by weight ratio 7:5, using multi-axial warp knitting machine, needle spacing 3mm, knitting needle density 16 needles / cm, warp tension 14cN, weft tension 12cN, knitting speed 14r / min, according to the shape of base mold, knitting forming, obtaining base prefabricated part, placing the base prefabricated part into the mold, using vacuum assisted resin transfer molding process, injecting resin compounded with inorganic filler, pressure impregnation for 20min, taking out the mold, removing the excess resin, then curing, the curing conditions are: first curing at 80℃ for 2h, then heating to 130℃ for 4h, cooling to room temperature, demolding, polishing burrs, obtaining the base; S2. Column support preparation: warp uses carbon fiber, weft uses modified polyester fiber prepared by preparation example 3 and basalt fiber mixed by weight ratio 7:5, select two-dimensional knitting machine, needle distance 2.5mm, knitting density 18 needles / cm, warp tension 17cN, weft tension 14cN, knitting speed 12r / min, according to the shape of column support mold, knitting forming, get column support preform, put the column support preform into the mold, use vacuum assisted resin transfer molding process, inject resin compounded with inorganic filler, pressure impregnation for 20min, take out the mold, remove the excess resin, then solidify, the solidification condition is: first solidify at 80℃ for 2h, then heat to 130℃ for 4h, cool to room temperature after demolding, polish burrs to get column support; S3. Rotatable mechanism preparation: warp uses modified polyester fiber prepared by preparation example 3 and aramid fiber mixed by weight ratio 8:4, weft uses modified polyester fiber prepared by preparation example 3 and basalt fiber mixed by weight ratio 8:4, use multi-axial warp knitting machine, needle distance 2.4mm, knitting density 17 needles / cm, warp tension 15cN, weft tension 13cN, knitting speed 13r / min, according to the shape of rotatable mechanism, knitting forming, get rotatable mechanism preform, put the rotatable mechanism preform into the mold, use vacuum assisted resin transfer molding process, inject resin compounded with inorganic filler, pressure impregnation for 20min, take out the mold, remove the excess resin, then solidify, the solidification condition is: first solidify at 80℃ for 3h, then heat to 130℃ for 4h, cool to room temperature after demolding, polish burrs, install bearing, get rotatable mechanism; S4. Cable trench support preparation: warp uses modified polyester fiber prepared by preparation example 3 and aramid fiber mixed by weight ratio 7:5, weft uses modified polyester fiber prepared by preparation example 3 and basalt fiber mixed by weight ratio 7:5, use multi-axial warp knitting machine, needle distance 2.5mm, knitting density 15 needles / cm, warp tension 14cN, weft tension 12cN, knitting speed 14r / min, according to the shape of cable trench support, knitting forming, embed the lock structure embedded part connected with rotatable mechanism in the process of knitting, get cable trench support preform, put the cable trench support preform into the mold, use vacuum assisted resin transfer molding process, inject resin compounded with inorganic filler, pressure impregnation for 20min, take out the mold, remove the excess resin and the lock structure embedded part connected with rotatable mechanism, then solidify, the solidification condition is: first solidify at 80℃ for 3h, then heat to 130℃ for 4h, cool to room temperature after demolding, polish burrs, install the lock structure connected with rotatable mechanism, get rotatable mechanism; S5. Install the column support vertically on the base, then install the rotatable mechanism between the column support and the cable trench support, get the woven type insulation composite cable support.

[0041] Comparative Example 1: The difference between Comparative Example 1 and Example 2 is that the polyester fiber prepared in Preparation Example 2 is replaced by the polyester fiber prepared in Comparative Preparation Example 1.

[0042] Comparative Example 2: The difference between Comparative Example 2 and Example 2 is that the polyester fiber prepared in Preparation Example 2 is replaced by the polyester fiber prepared in Comparative Preparation Example 2.

[0043] Comparative Example 3: The difference between Comparative Example 3 and Example 2 is that the polyester fiber prepared in Preparation Example 2 is replaced by the polyester fiber prepared in Comparative Preparation Example 3.

[0044] Comparative Example 4: The difference between Comparative Example 4 and Example 2 is that the polyester fiber prepared in Preparation Example 2 is replaced by the polyester fiber prepared in Comparative Preparation Example 4.

[0045] Comparative Example 5: The difference between Comparative Example 5 and Example 2 is that the polyester fiber prepared in Preparation Example 2 is replaced by the polyester fiber prepared in Comparative Preparation Example 5.

[0046] Comparative Example 6: The difference between Comparative Example 6 and Example 2 is that the polyester fiber prepared in Preparation Example 2 is replaced by the polyester fiber prepared in Comparative Preparation Example 6.

[0047] Performance test: According to the JB / T10216-2013 Cable Bridge for Electric Control Power Distribution, the mechanical properties, heat resistance, water resistance and insulation of the product obtained by the application are tested, and the experimental results are shown in Table 1.

[0048] Table 1 Performance test data of cable support

[0049] Performance analysis: From the experimental data in Table 1, it can be seen that the performance test data of the braided type insulation composite cable support prepared by Examples 1-3 are significantly better than those of the comparative examples, which reflect more excellent mechanical properties, heat resistance, flame retardance, corrosion resistance, insulation and water resistance. This is due to the precise raw material ratio and process design, which realizes the synergistic optimization of molecular structure and macroscopic performance. Among them, the comprehensive performance of Example 2 is the most outstanding.

[0050] In Example 2, the molecular chain structure of the modified polyester takes into account rigidity and structural integrity. The symmetric benzene ring structure provided by terephthalic acid lays a regular linear skeleton for the molecular chain, which is conducive to the orderly arrangement of the molecular chain and the formation of stable crystalline regions, thereby enhancing the overall rigidity. The asymmetric structure of isophthalic acid moderately breaks this high regularity, avoiding brittleness caused by excessive crystallization, so that the molecular chain can maintain its overall shape while having some deformation capacity when under stress. The double carboxylated DOPO is embedded in the molecular chain through covalent bonds, and its rigid heterocyclic structure further enhances the bending resistance of the chain segment. The bisphenol skeleton of hexafluorobisphenol A not only enhances the rigidity of the molecular chain, but also forms steric hindrance due to the strong electronegativity of the trifluoromethyl group, which inhibits the sliding of the chain segment when under stress. The 1-naphthalene carboxylic acid not only reduces the number of hydroxyl groups during end-capping, but also further introduces naphthalene ring structures, increasing the rigidity of the polyester matrix and improving its mechanical properties. Various inorganic fibers treated with silane coupling agent KH-550 form a strong "fiber-polyester interface bridge" with the polyester, effectively reducing the interfacial peeling phenomenon when under stress, allowing the fiber and polyester to work together to bear external loads, and ultimately exhibiting excellent bending resistance.

[0051] The notch impact performance is directly related to the material's ability to absorb and disperse impact energy. In Example 2, the introduction of isophthalic acid reduces the crystallinity of the polyester, increasing the proportion of flexible regions in the molecular chain and providing more space for chain movement and deformation. When impacted, the chain segments can absorb some of the energy through movement. The molecular structure of aramid fiber contains a large number of aromatic rings, which form stable rigid chain segments through conjugation effects. Meanwhile, the fiber itself has extremely high toughness. In the woven structure, aramid fibers and modified polyester fibers interweave to form an "elastic network." When impacted, the fibers can disperse stress through their own deformation, pulling out, and friction with the resin, avoiding stress concentration-induced fracture. In addition, the naphthalene ring introduced by 1-naphthalene carboxylic acid end-capping enhances the mutual attraction between molecular chains through π-π stacking, allowing impact energy to be transmitted through the coordinated movement of molecular chains to a larger area rather than being localized at the notch, thereby significantly improving the material's ability to absorb impact energy.

[0052] The load deformation reflects the material's resistance to deformation under stress, and is closely related to the rigidity of the molecular chain, the degree of entanglement, and the integrity of the reinforcing structure. In Example 2, trihydroxypropane as a branching agent introduces a small amount of branches into the polyester molecular chain, increasing the entanglement density between molecular chains and limiting the free sliding of chain segments, making it more difficult for the molecular chain to undergo relative displacement under load; the rigid heterocycle of double-carboxylated DOPO and the bisphenol skeleton of hexafluorobisphenol A together enhance the overall rigidity of the molecular chain, reducing the bending and stretching deformation of the chain segment under load; in the macrostructure, the tight weaving process of the multi-axial warp knitting machine makes the fibers uniformly distributed in the warp, weft and diagonal directions, and the reinforcing effect of the layered structure of talc in the compounded inorganic filler on the polyester matrix further inhibits the overall deformation of the material under load, ultimately showing a small load deformation.

[0053] The thermal deformation temperature depends on the rigidity of the molecular chain and the ability of intermolecular forces to suppress the thermal motion of the chain segment. In Example 2, the rigid heterocyclic structure of DOPO is covalently bonded to the polyester molecular chain, and its stable ring structure is difficult to twist or rotate at high temperatures, effectively limiting the thermal motion of the chain segment; the bisphenol skeleton of hexafluorobisphenol A also has high rigidity, and the induced effect of the strong electronegativity of the contained trifluoromethyl enhances the mutual attraction between molecules, making it more difficult for the molecular chain to relax at high temperatures; in addition, the step-by-step curing process ensures the full crosslinking of the resin, forming a dense three-dimensional network structure, reducing internal porosity and residual stress, and further improving the structural stability of the material at high temperatures. These factors work together to enable the molecular chain to maintain a stable arrangement at higher temperatures, resulting in a higher thermal deformation temperature.

[0054] The vertical combustion performance is mainly determined by the flame retardant mechanism of the material, including the synergistic effect of gas phase and condensed phase flame retardation. In Example 2, double-carboxylated DOPO is uniformly embedded in the polyester molecular chain through covalent bonds, and the phosphorus element contained therein generates phosphate intermediates during combustion. These intermediates can catalyze the dehydration of polymers to form a dense carbon layer on the surface of the material, blocking the transfer of oxygen and heat to the interior, and can also release phosphorus-containing free radicals to capture active free radicals in the gas phase, inhibiting the combustion chain reaction; the decomposition of aluminum hydroxide and magnesium hydroxide in the compounded inorganic filler at high temperatures releases heat and water vapor to dilute combustible gases, forming a synergistic effect with the flame retardant effect of DOPO. Compared to the uneven distribution and easy migration problems caused by physical mixing of flame retardants, the chemically combined DOPO structure in Example 2 ensures uniform distribution of the flame retardant components at the molecular level, ensuring the continuous and effective flame retardant mechanism during combustion, ultimately achieving excellent vertical combustion rating.

[0055] Corrosion resistance depends on the material's barrier ability to corrosion medium and its own chemical stability. In Example 2, the long-chain alkyl group introduced by octanediol has strong hydrophobicity, and its non-polar structure reduces the adsorption and infiltration of water molecules and polar corrosion medium on the material surface; the strong electronegativity of the trifluoromethyl group of hexafluorobisphenol A reduces the surface energy of the polyester molecular chain, further enhancing the hydrophobicity of the material, making it difficult for corrosion medium to spread and penetrate on the surface; the uniform distribution and moderate density of ester bonds in the molecular chain reduce the hydrolysis weak points caused by local ester bond intensive; at the same time, after the aramid fiber, basalt fiber and carbon fiber are treated with silane coupling agent KH-550, a stable chemical bond is formed at the interface between the polyester, avoiding the penetration of corrosion medium along the interface gap. These factors collectively enhance the material's resistance to corrosive environments, demonstrating excellent corrosion resistance.

[0056] Insulation strength is closely related to the polarity, charge transfer ability and internal structural defects of the material. In Example 2, the trifluoromethyl group of hexafluorobisphenol A is a non-polar group, and due to its strong electronegativity, the polarity of the molecular chain is reduced, reducing the charge transfer path on the molecular chain; the 1-naphthalene acid end-capping reaction reduces the number of hydroxyl groups at the end of the polyester molecular chain, and as a polar group, the reduction in the number of hydroxyl groups can reduce the conductivity of the material; the modified polyester molecular chain itself does not contain conductive groups, and the interface between the fibers treated with silane coupling agent and the resin is tightly bonded, avoiding the formation of "conductive channels" due to charge accumulation in the interface gap; the epoxy resin E-51 in the compounded resin itself has excellent insulation performance, and cooperates with inorganic fillers such as wollastonite to form a dense insulating structure, further hindering the transfer of charges, thereby making the material have a high insulation strength.

[0057] Water resistance mainly depends on the hydrophobicity and barrier ability of the material to water molecules. In Example 2, the 1-naphthalene acid end-capping reaction converts the hydroxyl groups at the end of the polyester molecular chain into naphthalene ring structure through esterification, significantly reducing the number of polar groups in the molecular chain, reducing the affinity between the material and water molecules, thereby reducing the adsorption of water molecules, the π-π stacking effect of naphthalene ring and the trifluoromethyl group of hexafluorobisphenol A enhances the intermolecular interaction force, making the molecular chain arrange more closely, reducing the gap that water molecules can penetrate; the long-chain alkyl group introduced by octanediol further enhances the hydrophobicity of the molecular chain, inhibiting the diffusion of water molecules into the material; in addition, the dense structure formed by multi-axial weaving and the full impregnation of the resin reduce the internal porosity of the material, avoiding the rapid penetration of water molecules through the pores, so that the material can maintain stable structure and mechanical properties after absorbing water, thus demonstrating excellent water resistance.

[0058] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art, according to the technical solution and inventive concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A braided insulated composite cable support, characterized in that, It includes the following structures: base, column support, rotatable mechanism, and cable trench support; The base is made of modified polyester fiber, basalt fiber and aramid fiber, which are woven and then cured with resin containing inorganic fillers. The column support is made of modified polyester fiber, basalt fiber and carbon fiber, which are woven and then cured with resin containing inorganic fillers. The rotatable mechanism is made of modified polyester fiber, aramid fiber and basalt fiber, which are woven and then cured with resin containing inorganic fillers. The cable trench support is made of modified polyester fiber, aramid fiber and basalt fiber, which are woven and then cured with resin containing inorganic fillers. The modified polyester fiber is prepared as follows: I. Under nitrogen protection, flame retardant DOPO and itaconic acid are added to 1,4-dioxane, the reaction vessel is sealed, the temperature is raised to 150-170℃, the reaction is carried out for 3-5 hours, the temperature is cooled to 0-10℃, and crystallization is carried out for 8-12 hours. A white solid is precipitated. After filtration, washing and drying, the filtrate is concentrated under reduced pressure, and then cooled, crystallized and filtered again. The two filtered products are combined and dried under reduced pressure to obtain dicarboxylated DOPO. II. Under nitrogen protection, terephthalic acid, isophthalic acid, dicarboxylated DOPO, ethylene glycol, octane glycol, and hexafluorobisphenol A are added to a reaction vessel. Molecular sieves are added, and the pressure is increased to 0.2-0.3 MPa. The temperature is raised to 200-220℃, and the reaction is carried out for 2-4 hours. Then, trihydroxypropane and catalyst are added, the pressure is restored to normal, and the temperature is raised to 240-280℃. The reaction is carried out for 4-6 hours. Then, 1-naphthoic acid is added, and the reaction is carried out for 1-2 hours. The molecular sieves are separated while hot, and the product is added to ethanol at 0-10℃ while hot to precipitate. The precipitate is washed, dried, and granulated to obtain modified polyester. III. Modified polyester is added to a twin-screw extruder. After melt extrusion, it is conveyed to a spinneret with an orifice diameter of 0.2-0.35 mm via a metering pump at a speed of 10-20 rpm. After extrusion, the fine stream is passed through a ring blowing system at a temperature of 15-25℃ and a speed of 0.4-0.6 m / s for rapid cooling and solidification to obtain nascent fibers. These fibers are then stretched using a stretching machine. Finally, they undergo tension heat setting at a temperature of 175-185℃ for 1.5-2.5 min to eliminate internal stress and obtain modified polyester fibers.

2. The braided insulated composite cable support according to claim 1, characterized in that, The inorganic filler refers to aluminum hydroxide, magnesium hydroxide, talc, and wollastonite. The resin compounded with the inorganic filler is epoxy resin E-51, methyl hexahydrophthalic anhydride, aluminum hydroxide, magnesium hydroxide, talc, and wollastonite mixed in a weight ratio of 7:3:0.6:0.6:0.4:0.

03. Aramid fibers, basalt fibers, and carbon fibers are treated with silane coupling agent KH-550. The specific treatment process is as follows: the aramid fibers, basalt fibers, and carbon fibers are unfolded separately, surface impurities and oil stains are removed, and then they are immersed in a solution containing silane coupling agent KH-550. Under stirring, they are soaked for 10-20 minutes. After soaking, they are taken out, rinsed with ethanol, and dried. The silane coupling agent solution is prepared by mixing silane coupling agent KH-550, ethanol, and deionized water in a weight ratio of 1:9:

1.

3. The braided insulated composite cable support according to claim 1, characterized in that, In section I, the molar ratio of flame retardant DOPO and itaconic acid is 1:1-1.1, and the weight ratio of flame retardant DOPO and 1,4-dioxane is 1:8-12. In section II, the molar ratio of terephthalic acid, isophthalic acid, dicarboxylated DOPO, ethylene glycol, octane glycol, hexafluorobisphenol A, and trihydroxypropane is 4-6:2-4:1-3:5-7:1-3:1-3:0.1-0.4, and the total mass of terephthalic acid, isophthalic acid, dicarboxylated DOPO, ethylene glycol, octane glycol, hexafluorobisphenol A, and trihydroxypropane, along with the weight ratio of molecular sieve, catalyst, and 1-naphthoic acid, is 1:0.05-0.15:0.03-0.07:0.01-0.

03. The catalyst refers to tetrabutyl titanate.

4. The braided insulated composite cable support according to claim 1, characterized in that, The parameters of the twin-screw extruder in section III are as follows: Zone 1 temperature: 255-265℃, Zone 2 temperature: 265-275℃, Zone 3 temperature: 275-285℃, Zone 4 temperature: 285-295℃, Die head temperature: 285-295℃, Screw speed: 25-35 rpm. The stretching parameters of the stretching machine are: First-stage stretching temperature: 75-85℃, stretching ratio: 2.3-2.8; Second-stage stretching temperature: 95-105℃, stretching ratio: 1.4-1.8; Third-stage stretching temperature: 115-125℃, stretching ratio: 0.9-1.

1.

5. The method for preparing the braided insulated composite cable bracket according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Base preparation: The warp yarn is a mixture of modified polyester fiber and basalt fiber, and the weft yarn is a mixture of modified polyester fiber and aramid fiber. The base is woven into shape according to the base mold using a multi-axial warp knitting machine to obtain a base preform. The base preform is placed into the mold and a vacuum-assisted resin transfer molding process is used to inject resin compounded with inorganic fillers. The mixture is impregnated under pressure for 10-20 minutes. The mold is removed, excess resin is removed, and then the mixture is cured. The curing conditions are: first, cure at 70-80℃ for 1-2 hours, then raise the temperature to 120-130℃ for 3-4 hours. After cooling to room temperature, the base is demolded and the burrs are removed to obtain the base. S2. Preparation of column support: The warp is made of carbon fiber and the weft is made of a mixture of modified polyester fiber and basalt fiber. A two-dimensional braiding machine is used to braid the column support according to the shape of the mold to obtain the column support preform. The column support preform is placed into the mold and a vacuum-assisted resin transfer molding process is used to inject resin mixed with inorganic fillers. The resin is held under pressure for 10-20 minutes. The mold is removed, excess resin is removed, and then the column support is cured. The curing conditions are: first, cure at 70-80℃ for 1-2 hours, then raise the temperature to 120-130℃ for 3-4 hours. After cooling to room temperature, the column support is demolded and the burrs are removed to obtain the column support. S3. Preparation of the rotatable mechanism: The warp yarn is a mixture of modified polyester fiber and aramid fiber, and the weft yarn is a mixture of modified polyester fiber and basalt fiber. The rotatable mechanism is woven into shape using a multi-axial warp knitting machine to obtain a preform of the rotatable mechanism. The preform of the rotatable mechanism is placed in a mold, and a vacuum-assisted resin transfer molding process is used to inject resin compounded with inorganic fillers. The mixture is impregnated under pressure for 10-20 minutes. The mold is removed, excess resin is removed, and then the mixture is cured. The curing conditions are: first, cure at 70-80℃ for 2-3 hours, then raise the temperature to 120-130℃ for 3-4 hours. After cooling to room temperature, the mixture is demolded, burrs are removed, and bearings are installed to obtain the rotatable mechanism. S4. Cable trench support preparation: The warp yarn is a mixture of modified polyester fiber and aramid fiber, and the weft yarn is a mixture of modified polyester fiber and basalt fiber. A multi-axial warp knitting machine is used to knit the cable trench support according to its shape. During the knitting process, a pre-embedded locking structure connected to the rotatable mechanism is embedded to obtain a pre-fabricated cable trench support. The pre-fabricated cable trench support is placed in a mold and a vacuum-assisted resin transfer molding process is used to inject resin compounded with inorganic fillers. The mixture is then impregnated under pressure for 10-20 minutes. The mold is removed, excess resin and the pre-embedded locking structure connected to the rotatable mechanism are removed, and then the mixture is cured. The curing conditions are: first, cure at 70-80℃ for 2-3 hours, then raise the temperature to 120-130℃ for 3-4 hours, cool to room temperature, demold, and after deburring, install the locking structure connected to the rotatable mechanism to obtain the rotatable mechanism. S5. Vertically install the column bracket on the base, and then install the rotatable mechanism between the column bracket and the cable trench bracket to obtain the braided insulated composite cable bracket.

6. The method for preparing the braided insulated composite cable bracket according to claim 5, characterized in that, The modified polyester fiber and basalt fiber in the S1 warp are in a weight ratio of 5-8:2-4, and the modified polyester fiber and aramid fiber in the weft are in a weight ratio of 5-7:3-5. The needle pitch in the multi-axial warp knitting machine is 2-3 mm, the needle density is 12-16 needles / cm, the warp tension is 10-14 cN, the weft tension is 8-12 cN, and the knitting speed is 10-14 r / min.

7. The method for preparing the braided insulated composite cable bracket according to claim 5, characterized in that, The modified polyester fiber and basalt fiber in the S2 weft yarn are in a weight ratio of 5-7:3-5. The needle pitch in the two-dimensional warp knitting machine is 1.5-2.5mm, the needle density is 14-18 needles / cm, the warp tension is 13-17cN, the weft tension is 10-14cN, and the knitting speed is 8-12r / min.

8. The method for preparing the braided insulated composite cable bracket according to claim 5, characterized in that, The modified polyester fiber and aramid fiber in the S3 warp are in a weight ratio of 5-8:2-4, and the modified polyester fiber and basalt fiber in the weft are in a weight ratio of 5-8:2-4. The needle pitch in the multi-axial warp knitting machine is 2-2.4 mm, the needle density is 13-17 needles / cm, the warp tension is 11-15 cN, the weft tension is 9-13 cN, and the knitting speed is 9-13 r / min.

9. The method for preparing the braided insulated composite cable bracket according to claim 5, characterized in that, The modified polyester fiber and aramid fiber in the S4 warp are in a weight ratio of 5-7:3-5, and the modified polyester fiber and basalt fiber in the weft are in a weight ratio of 5-7:3-5. The needle pitch in the multi-axial warp knitting machine is 2.1-2.5mm, the needle density is 13-15 needles / cm, the warp tension is 10-14cN, the weft tension is 8-12cN, and the knitting speed is 10-14r / min.

10. The application of the braided insulated composite cable support obtained by the preparation method according to any one of claims 5-9 in cable duct manholes, public power system cable projects, user-built and self-used dedicated power facility cable projects, and high and low voltage cable projects.

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