Snow-melting bridge cable sheath material and preparation method thereof

Abstract

The invention relates to the technical field of high polymer materials, and particularly discloses a snow-melting bridge cable sheath material and a preparation method thereof. The snow-melting bridge cable sheath material is prepared from the following raw materials in parts by weight: 100 parts of PE resin, 8 to 15 parts of polyolefin elastomer, 0.1 to 0.4 part of light stabilizer, 0.3 to 0.5 part of antioxidant, 1.5 to 2 parts of lubricant, 5 to 6 parts of black master batch, 4 to 8 parts of snow-melting material and 2 to 5 parts of preservative, the snow melting material is PAN (Polyacrylonitrile) nanofiber loaded with sodium chloride. The bridge cable sheath material provided by the invention has strong low-temperature impact resistance and good low-temperature crack resistance, has certain snow-melting and anti-freezing effects, reduces the accumulation amount of ice and snow, and relieves cable tension.

Description

Technical Field

[0001] The present application relates to the technical field of polymer materials, and more specifically, to a snow-melting bridge cable sheath material and a preparation method thereof. Background Art

[0002] The cable system of a bridge is the main load-bearing structure of a modern long-span bridge, and plays a vital role in the life and quality of the bridge. The cable of a bridge is generally composed of steel strands or wire ropes and anchors, but because the material is steel, it is easy to age and rust, so it is necessary to cover the cable with a sheath material.

[0003] When selecting protective materials, the material's resistance to environmental stress cracking is a very important property, because under the corrosion of light, heat, water, pollutants, etc., the sheath is prone to performance changes, resulting in cracks, affecting the protection effect and reducing the service life of the cable. High-density polyethylene material is the preferred material for sheath materials because of its stable performance, good strength and toughness.

[0004] In the prior art, a Chinese invention patent application document with application number CN2016112272561 discloses a bridge cable sheath material and a preparation method thereof. The special sheath material for bridge cables comprises, by weight, 50 to 80 parts of high-density polyethylene, 10 to 40 parts of low-density polyethylene, 5 to 10 parts of vinyl trimethoxy silane, 1.0 to 10 parts of masterbatch, 0.5 to 1.0 parts of antioxidant, 0.5 to 1.0 parts of compound ultraviolet absorber, and 0.5 to 1.0 parts of compound plastic modifier.

[0005] The above-mentioned bridge cable sheath material has good physical and mechanical properties and resistance to environmental stress cracking, but its crack resistance at low temperatures needs to be improved. In relatively cold areas, the cable itself may cause brittle cracking due to low temperatures. In addition, as the amount of snow increases, ice and snow continue to accumulate on the bridge cable, which will increase the load on the cable. If the cable has been used for a long time and has tiny cracks or cracks, and the snow load exceeds the cable's bearing capacity, the bridge cable may break, and the snow may also corrode the cable, further reducing its tensile performance. Summary of the invention

[0006] In order to increase the toughness of cables at low temperatures, reduce their low-temperature brittleness, and reduce the accumulation of ice and snow on bridge cables, the present application provides a snow-melting bridge cable sheath material and a preparation method thereof.

[0007] In the first aspect, the present application provides a snowmelt bridge cable sheath material, which adopts the following technical solution: A snow-melting bridge cable sheath material comprises the following raw materials in parts by weight: 100 parts of PE resin, 8-15 parts of polyolefin elastomer, 0.1-0.4 parts of light stabilizer, 0.3-0.5 parts of antioxidant, 1.5-2 parts of lubricant, 5-6 parts of black masterbatch, and 4-8 parts of snow-melting material.

[0008] By adopting the above technical scheme, PE resin is used as the main material and polyolefin elastomer is added. The polyolefin elastomer has excellent elasticity and can undergo large deformation without breaking easily when subjected to external force, which helps to improve the toughness of PE resin. At the same time, its high elongation can also absorb more energy during the stretching process, thereby enhancing the impact resistance of the sheath material. In addition, the structure of polyolefin elastomer is similar to that of PE resin and the compatibility is good. POE can be evenly dispersed in PE resin to form a stable blending system, thereby improving the overall performance of the sheath material. The snow-melting material can reduce the accumulation of ice and snow on the surface of the cable when it snows, reduce the load-bearing capacity of the cable, and improve safety.

[0009] Optionally, the snow-melting material is PAN nanofiber loaded with sodium chloride.

[0010] By adopting the above technical scheme, sodium chloride is a material with good ice melting effect, and its freezing point is lower than that of pure water, so it can melt ice and snow at a lower temperature. Moreover, the dissolution of sodium chloride in water is an endothermic process, which can absorb heat from the surroundings, which helps to further reduce the temperature of ice and snow and accelerate its melting process. In addition, sodium chloride can also change the crystal structure of ice and snow, making it easier to be destroyed and melted, thereby accelerating the decomposition of ice and snow. PAN nanofibers have high strength and high modulus and can withstand ice dispersion external forces, so that they can effectively enhance the mechanical strength of PE sheath materials, improve the strength and toughness of sheath materials, and hinder the expansion of cracks in sheath materials, and improve the interface bonding force between sheath materials and cable bodies, ensuring that stress is effectively transmitted in sheath materials, thereby improving the finishing mechanical properties, and thus improving the impact resistance, durability and toughness of sheath materials.

[0011] Optionally, the sodium chloride-loaded PAN nanofiber is prepared by the following method: Dissolving polyurethane, adding PVP and boron nitride nanosheets to obtain a core layer liquid with a polyurethane concentration of 18-20wt%, and a mass ratio of polyurethane, PVP and boron nitride nanosheets of 1:1.5-2:0.2-0.3; Dispersing cellulose nanocrystals in DMF, adding PAN powder, and mixing evenly to prepare a shell liquid with a PAN concentration of 14-15wt%, and a mass ratio of cellulose nanocrystals to PAN of 0.1-0.2:1; The core layer liquid and the shell layer liquid were coaxially electrospun to obtain nanofibers, which were then immersed in deionized water and dried to obtain porous PAN nanofibers. The core-shell solution flow rate ratio was 5:1. The porous PAN nanofibers are immersed in a saturated sodium chloride solution, heated to 70-80° C., stirred for 5-6 hours, and dried to a constant weight, wherein the mass ratio of the porous PAN nanofibers to the sodium chloride is 15-20:20.

[0012] By adopting the above technical scheme, coaxial electrospinning technology is used to prepare nanofibers with cellulose nanocrystals and PAN as shells and PVP, polyurethane and boron nitride nanosheets as cores. PVP is easily dissolved and etched away by water, so after soaking in deionized water, PVP is dissolved and removed, and a channel structure extending along the fiber direction is created on the surface of the nanofiber. A channel structure that opens the internal space of the fiber appears on the nanofiber, thereby increasing the gap between fibers, thereby increasing the average pore size, which is convenient for the loading of sodium chloride; after the PVP in the core layer is dissolved and removed, polyurethane and boron nitride nanosheets are used as the core layer. The boron nitride nanosheet has high thermal conductivity, which can increase the absorption of heat by the sheath material, thereby enhancing the ice and snow melting ability. Moreover, polyurethane is used as the inner layer through coaxial electrospinning, which can effectively compensate for the decrease in the mechanical strength of the nanofibers caused by the removal of PVP. Therefore, the prepared PAN nanofibers loaded with sodium chloride can effectively enhance the low-temperature impact resistance and flexibility of the sheath material, while improving the ice and snow melting ability.

[0013] Optionally, the sodium chloride-loaded PAN nanofibers are pretreated by vapor deposition of methyltrichlorosilane.

[0014] By adopting the above technical scheme, the hydrophilic hydroxyl groups on the surface of cellulose nanocrystals make the porous PAN nanofibers more hydrophilic. Therefore, the PAN nanofibers loaded with sodium chloride may have poor dispersion in the PE resin. Therefore, methyltrichloromethane is used to form a layer of organic silicon film on the PAN nanofibers loaded with sodium chloride by vapor deposition, thereby giving the material excellent hydrophobic properties. Methyltrichloromethane can also undergo silanol reaction with hydroxyl groups to further enhance the hydrophobicity of the material surface, thereby improving the dispersion of PAN nanofibers loaded with sodium chloride in the sheath material, thereby enhancing the overall mechanical strength of the sheath material.

[0015] Optionally, the PE resin includes ultra-high molecular weight polyethylene and high density polyethylene in a mass ratio of 1:1-1.5.

[0016] By adopting the above technical scheme, ultra-high molecular weight polyethylene has a longer molecular chain due to its extremely high molecular weight, which enables it to maintain good flexibility and impact strength at low temperatures, and its brittle temperature reaches -140°C, and it is still ductile at -269°C, so that it can work at temperatures close to zero degrees. The molecular chains of high-density polyethylene and ultra-high molecular weight polyethylene are similar, and the blends have good compatibility. High-density polyethylene can penetrate into the molecular chains of ultra-high molecular weight polyethylene, untie some of the physical entanglements, and obtain a mutually penetrating and continuous homogeneous form, thereby increasing the fluidity of ultra-high molecular weight polyethylene, improving its processing performance, and obtaining a sheath material raw material with better low-temperature impact resistance.

[0017] Optionally, hydrophobically modified polyvinyl alcohol aerogel is further added to the PE resin, and the mass ratio of the hydrophobically modified polyvinyl alcohol aerogel to high-density polyethylene is 0.1-0.2:1.

[0018] By adopting the above technical scheme, the polyvinyl alcohol aerogel is hydrophobically modified and its non-polarity is enhanced, so it can be dispersed more evenly in raw materials such as high-density polyethylene. The nanoscale void structure of the polyvinyl alcohol aerogel helps to improve the low-temperature toughness of high-density polyethylene, and the thermal insulation effect of the polyvinyl alcohol aerogel can slow down the cooling rate of the sheath material at low temperatures and reduce the risk of cracking.

[0019] Optionally, the hydrophobically modified polyvinyl alcohol aerogel is prepared by the following method: Dispersing titanium carbide in deionized water, ultrasonically dispersing, adding aramid nanofibers, and ultrasonically dispersing to obtain a dispersion, wherein the mass ratio of titanium carbide to aramid nanofibers is 0.1-0.2:2; Adding polyvinyl alcohol to the dispersion, stirring at 90-100° C. for 2-3 hours and then freezing, thawing and immersing in a potassium hydroxide solution, taking out, and freeze-drying to obtain an aerogel, wherein the mass ratio of polyvinyl alcohol to aramid fiber is 3-4:1; The aerogel is immersed in a graphene oxide solution, filtered and dried at 60-70° C. for 22-24 hours, immersed in a hydrogen iodide aqueous solution, kept warm at 70-80° C. for 12-15 hours, filtered, washed and dried to obtain a hydrophobically modified polyvinyl alcohol aerogel.

[0020] By adopting the above technical scheme, rigid fillers titanium carbide and aramid nanofibers are introduced into the polyvinyl alcohol network structure, and hydrophobically modified polyvinyl alcohol aerogel is prepared by freezing, thawing and potassium hydroxide impregnation. There is a strong hydrogen bond interaction between the aramid nanofibers and the polyvinyl alcohol, which promotes the crystallization of the polyvinyl alcohol, thereby obtaining a double network formed by the aramid nanofibers and the polyvinyl alcohol connected by hydrogen bonds, so that the mechanical capacity of the polyvinyl alcohol aerogel is enhanced. In addition, the aramid nanofiber is an organic filler with a high specific surface area, which provides more sites for bonding with the polymer interface. Therefore, the interaction between the aramid nanofibers and the polyvinyl alcohol introduces a Energy dissipation mechanism helps to improve mechanical strength; titanium carbide nanosheets are very easy to aggregate in water, and the addition of aramid nanofibers improves the stability in the later stage and maintains a good dispersion state, because aramid fiber nano and titanium carbide can form hydrogen bonds, which stabilizes the dispersion of titanium carbide nanosheets. Titanium carbide has good thermal conductivity and can absorb external heat, accelerate the melting of ice and snow, and reduce the accumulation of ice and snow on the sheath material. After being impregnated with potassium hydroxide solution, the toughness can be further improved, because the hydroxyl groups in potassium hydroxide interact with the hydroxyl groups on the polyvinyl alcohol polymer chain and the aramid nanofibers, inducing the production of -O - and -COO - Due to the electrostatic force and intermolecular hydrogen bonds, the double network cross-linking is more solid. The hydrogen bonding between polyvinyl alcohol and water molecules can inhibit the formation of ice crystals and lower the freezing point. The addition of aramid nanofibers and titanium carbide further enhances the hydrogen bonding of the system. After immersion in potassium hydroxide solution, the salt concentration inside the gel increases, and the OH in the potassium hydroxide solution - It combines with the hydroxyl groups of the polyvinyl alcohol polymer chains and aramid nanofibers in the gel, inducing the ionization of the hydroxyl groups on the polyvinyl alcohol and aramid nanofibers, making the double network cross-linking stronger and the formation of ice crystals more difficult.

[0021] A large number of oxygen-containing groups such as hydroxyl, carboxyl and epoxy groups are grafted on the surface of graphene oxide, so that the surface can absorb a large amount of free water, forming a thick water film with good dispersibility. When the aerogel is impregnated on the graphene oxide, the graphene oxide can form a graphene oxide film on the surface and in the gaps of the aerogel. After reduction with hydrogen iodide, the oxygen-containing functional groups on the surface of the graphene oxide are removed, making it hydrophobic. The attachment of graphene further improves the tensile strength, flexibility and flexural resistance of the aerogel, thereby obtaining a hydrophobically modified polyvinyl alcohol aerogel that can further improve the mechanical properties of the sheath material. In addition, graphene has extremely high thermal conductivity and can absorb external heat in the sheath material to accelerate the melting of ice and snow.

[0022] Optionally, the black masterbatch is prepared by mixing and granulating polyethylene, polysiloxane and carbon black in a mass ratio of 1:0.8-1:0.3-0.5.

[0023] By adopting the above technical scheme, polyethylene resin and ultra-high molecular weight polysiloxane are used as the main body, carbon black is used as the pigment, and after being kneaded evenly by mixing and kneading, a black masterbatch is obtained by extrusion. The polysiloxane is an ultra-high molecular weight polysiloxane selected from Dow Corning MBSI-002P, which is a special polymer material with a semi-organic and semi-inorganic structure and has unique properties. Due to its own characteristics, the silicone component in the masterbatch is partially compatible with the CC chain in the plastic, so that they can play a unique role with each other and will not be completely submerged and assimilated by the basic polymer to fail. Therefore, a better lubrication and dispersion effect can be achieved, and at the same time, the surface lubrication and smoothness of the sheath material are increased, the friction between the sheath material and the snow is reduced, and the accumulation of snow is reduced. At the same time, the hydrophobic effect of the sheath material is increased, and the condensation of snow on the surface of the sheath material is reduced.

[0024] Optionally, the preservative is prepared by the following method: Nano titanium nitride and silicon dioxide are dispersed in an ethanol solution of KH570, the pH is adjusted to 4-5, the temperature is raised to 60-65°C for reaction for 2-2.5 hours, the solution is dispersed in anhydrous ethanol after centrifugation and washing, octadecyl methacrylate and 2,2-azobisisobutyronitrile are added, the solution is stirred at 60-65°C for 2-3 hours, filtered and dried to obtain a preservative.

[0025] By adopting the above technical scheme, KH570 is used to chemically modify silica microspheres and nano-titanium nitride particles through a hydrolysis condensation reaction. The hydrolysis product of KH570 in an acidic medium can react with the hydroxyl groups on the surface of the silica microspheres and nano-titanium nitride particles to form alkylated particles. Subsequently, 2,2-azobisisobutyronitrile is used as an initiator to graft the super-hydrophobic alkyl chain of octadecyl methacrylate onto the particle surface through a double bond polymerization reaction. The silica and nano-titanium nitride mixture has an obvious micro-nano structure and excellent super-hydrophobicity, so that the sheath material has a micro-nano structure and low surface energy, thereby obtaining a strong hydrophobicity, thereby reducing the penetration of water, reducing the accumulation of ice and snow, and reducing the corrosion of ice and snow.

[0026] Optionally, the antioxidant is selected from at least one of antioxidant 1010, antioxidant 168 and antioxidant 1076; the lubricant is selected from at least one of stearamide, calcium stearate, paraffin, polyethylene wax and acrylic wax.

[0027] By adopting the above technical solution, antioxidants can capture and neutralize free radicals, prevent polymer chains from breaking due to oxidation during processing and use, help maintain the physical properties of the sheath material, and extend its service life; antioxidants can also enhance the stability of the polymer at high temperatures, prevent it from losing performance due to thermal degradation, and also reduce the degradation of the polymer during processing, maintaining its melt fluidity and processing performance.

[0028] Lubricants can form a lubricating layer between the polymer melt and the processing equipment, reduce friction resistance, make the melt easier to extrude and shape, help improve production efficiency and reduce energy consumption; they can also reduce the viscosity of the polymer melt, improve its fluidity, help ensure the uniformity and quality consistency of the sheath material, and prevent the polymer melt from sticking together during processing, reduce the generation of crystal points, and help keep the production equipment clean and operating normally.

[0029] In a second aspect, the present application provides a method for preparing a snowmelt bridge cable sheath material, using the following technical solution: A method for preparing a snow-melting bridge cable sheath material comprises the following steps: PE resin, polyolefin elastomer, light stabilizer, antioxidant, lubricant, black masterbatch, snow melting material and preservative are uniformly mixed and then extruded and granulated. The extrusion temperature is 190-210°C and the screw speed is 450-550Hz.

[0030] By adopting the above technical solution, the raw materials are blended, extruded and granulated to obtain the sheath material, which is simple to prepare and easy to realize large-scale production.

[0031] In summary, this application has the following beneficial effects: 1. Since the present application adopts PE resin, antioxidant, lubricant and snow-melting material to prepare the sheath material, a sheath material with strong low-temperature toughness and certain ice-melting and snow-melting ability can be obtained, which can reduce the accumulation of ice and snow on the cable and the occurrence of low-temperature cracking.

[0032] 2. In the present application, PAN nanofibers loaded with sodium chloride are preferably used as snow-melting materials, and PVP, polyurethane and boron nitride nanosheets are used as core layers when preparing the material, and cellulose nanocrystals and PAN are used as shell layers. PVP is removed by soaking in deionized water, and then immersed in a saturated sodium chloride solution. Therefore, sodium chloride can be loaded on the porous PAN nanofibers to obtain a certain snow-melting and anti-icing effect. At the same time, the nanofiber material has polyurethane and boron nitride nanosheets as the core layer, which can improve the mechanical strength of the snow-melting material and the low-temperature toughness of the sheath material. In addition, the addition of boron nitride nanosheets can further enhance the snow-melting ability.

[0033] 3. In the present application, ultra-high molecular weight polyethylene and high-density polyethylene are preferably used as PE resin raw materials, and hydrophobically modified polyvinyl alcohol aerogel is added. The ultra-high molecular weight polyethylene can make the sheath material have excellent low-temperature impact resistance, and the hydrophobically modified polyvinyl alcohol aerogel can be evenly dispersed in the PE resin raw material, further improving the mechanical properties of the sheath material; the hydrophobically modified polyvinyl alcohol aerogel forms a double network structure of aramid nanofibers and polyvinyl alcohol, and titanium carbide and graphene are added to improve its thermal conductivity and enhance its snow melting effect. DETAILED DESCRIPTION

[0034] The following examples further illustrate the present application in detail.

[0035] Preparation Example 1-6 of PAN Nanofibers Loaded with Sodium Chloride In the following preparation examples, the sources of the raw materials are: polyurethane is selected from BASF of Germany, model 1190A10, PVP molecular weight is 360000, selected from Shanghai Yuanye Biotechnology Co., Ltd., model S31099, boron nitride nanosheets are selected from Changzhou Lima Drying Technology, model BN, PAN powder molecular weight is 85000, selected from BASF of Germany, item number 20180452782, Preparation Example 1: (1) 2g of polyurethane was dissolved in DMF and butyl acetate in a volume ratio of 4:6, 4g of PVP and 0.6g of boron nitride nanosheets were added, and mixed evenly to obtain a core layer liquid with a polyurethane concentration of 20wt%; (2) 0.2 g of cellulose nanocrystals were dispersed in DMF, 1 g of PAN powder was added, and the mixture was mixed evenly to prepare a shell liquid with a PAN concentration of 14 wt%; (3) The core layer liquid and the shell layer liquid were coaxially electrospun to obtain nanofibers, and the nanofibers were immersed in deionized water for 12 h and dried at 60 ° C for 3 h to obtain porous PAN nanofibers. The shell layer liquid injection rate was 0.6 mL / h, the core-shell solution flow rate ratio was 5:1, the spinning voltage was 20 kV, and the receiving distance was 20 cm; (4) 15 g of porous PAN nanofibers were immersed in a saturated sodium chloride solution, heated to 80° C., stirred for 5 h, and dried to constant weight to obtain PAN nanofibers loaded with sodium chloride. The mass ratio of porous PAN nanofibers to sodium chloride was 15:20.

[0036] Preparation Example 2: (1) 1.8 g of polyurethane was dissolved in DMF and butyl acetate in a volume ratio of 4:6, 2.7 g of PVP and 0.36 g of boron nitride nanosheets were added, and the mixture was mixed evenly to prepare a core layer liquid having a polyurethane concentration of 18 wt %; (2) 0.1 g of cellulose nanocrystals were dispersed in DMF, 1 g of PAN powder was added, and the mixture was mixed evenly to prepare a shell liquid with a PAN concentration of 15 wt%; (3) The core layer liquid and the shell layer liquid were coaxially electrospun to obtain nanofibers, and the nanofibers were immersed in deionized water for 12 h and dried at 60 ° C for 3 h to obtain porous PAN nanofibers. The shell layer liquid injection rate was 0.6 mL / h, the core-shell solution flow rate ratio was 5:1, the spinning voltage was 20 kV, and the receiving distance was 20 cm; (4) 20 g of porous PAN nanofibers were immersed in a saturated sodium chloride solution, heated to 70° C., stirred for 6 h, and dried to constant weight to obtain PAN nanofibers loaded with sodium chloride. The mass ratio of porous PAN nanofibers to sodium chloride was 15:20.

[0037] Preparation Example 3: The difference from Preparation Example 1 is that no boron nitride nanosheets are added to the core layer solution.

[0038] Preparation Example 4: The difference from Preparation Example 1 is that no boron nitride nanosheets and polyurethane are added to the core layer solution, and PVP and DMF are mixed and dissolved to prepare a core layer solution with a concentration of 20 wt%.

[0039] Preparation Example 5: The difference from Preparation Example 1 is that no cellulose nanocrystals are added to the shell solution.

[0040] Preparation Example 6: The difference from Preparation Example 1 is that trimethyltrichlorosilane is vapor deposited on the PAN nanofibers loaded with sodium chloride. The method is as follows: methyltrichlorosilane is placed in a dryer, the PAN nanofibers loaded with sodium chloride are suspended above the dryer, the dryer is sealed, the reaction is carried out at 60°C for 2 hours, and the reaction is allowed to stand in a fume hood for 6 hours to remove the reaction product HCl.

[0041] Preparation Example 7-12 of Hydrophobically Modified Polyvinyl Alcohol Aerogel The amounts of raw materials used in Preparation Example 7 are as follows: titanium carbide is selected from Nangong Xindun Alloy Welding Material, brand TIMP2, item number 54423, polyvinyl alcohol is selected from Shanghai Hufeng Chemical Co., Ltd., model 1799, and graphene oxide is selected from Hunan Fenghua Materials, item number 01, model FH-661.

[0042] Preparation Example 7: 0.2 g of titanium carbide was dispersed in 12 g of deionized water, ultrasonically dispersed for 30 min, 2 g of aramid nanofiber was added, and ultrasonically dispersed for 10 min to obtain a dispersion; the aramid nanofiber was prepared by the following method: 1.8 g of Kevlar pulp and 2.7 g of potassium hydroxide were added to 85.5 g of dimethyl sulfoxide, stirred at 65° C. for 4 d until it turned dark red, and a deprotonated aramid nanofiber dispersion was obtained, the mass fraction of which was 2%, and dried to constant weight; 6 g of polyvinyl alcohol was added to the dispersion, stirred at 100°C for 2 hours, then frozen at -45°C for 10 hours, thawed at room temperature for 1 hour, cycled freezing-thawing for 3 times, immersed in a potassium hydroxide solution with a concentration of 4 mol / l for 2 days, taken out, and freeze-dried to obtain an aerogel; The aerogel was immersed in a graphene oxide solution with a concentration of 5 mg / ml, filtered after immersion for 2 hours, dried at 60°C for 24 hours, then immersed in a 1% volume fraction of hydrogen iodide aqueous solution, and then kept warm at 80°C for 12 hours, filtered, washed with deionized water and anhydrous ethanol for 3 times respectively, and dried to obtain a hydrophobically modified polyvinyl alcohol aerogel.

[0043] Preparation Example 8: 0.1 g of titanium carbide was dispersed in 12 g of deionized water, and ultrasonically dispersed for 30 min, and 2 g of aramid nanofiber was added, and ultrasonically dispersed for 10 min to obtain a dispersion; 8 g of polyvinyl alcohol was added to the dispersion, stirred at 90°C for 3 h, then frozen at -45°C for 10 h, thawed at room temperature for 1 h, cycled freezing-thawing for 3 times, immersed in a 4 mol / l potassium hydroxide solution for 2 days, taken out, and freeze-dried to obtain an aerogel; The aerogel was immersed in a graphene oxide solution with a concentration of 5 mg / ml, filtered after immersion for 2 hours, dried at 70°C for 22 hours, and then immersed in a 1% volume fraction of hydrogen iodide aqueous solution, and then kept warm at 70°C for 15 hours, filtered, washed with deionized water and anhydrous ethanol for 3 times respectively, and dried to obtain a hydrophobically modified polyvinyl alcohol aerogel.

[0044] Preparation Example 9: The difference from Preparation Example 7 is that no titanium carbide is added to the dispersion.

[0045] Preparation Example 10: The difference from Preparation Example 7 is that no aramid nanofibers are added to the dispersion.

[0046] Preparation Example 11: The difference from Preparation Example 7 is that the aerogel is not impregnated with graphene oxide solution and hydrogen iodide aqueous solution, and the prepared aerogel is a hydrophobically modified polyvinyl alcohol aerogel.

[0047] Preparation Example 12: The difference from Preparation Example 7 is that the aerogel is only immersed in the graphene oxide solution, and not immersed in the hydrogen iodide aqueous solution. Example

[0048] The sources of raw materials in the following embodiments are as follows: ultra-high molecular weight polyethylene is selected from Japan Mitsui Chemicals with the brand name L3000, high-density polyethylene is selected from Yanshan Petrochemical with the model name B5703, polyolefin elastomer is selected from ExxonMobil with the brand name Vistamaxx 6202, polyethylene wax is selected from Henan Lisen Chemical Products with the model name PE-WAX, and commercially available black masterbatch is selected from Zhengzhou Economic and Technological Development Zone Senjie Chemical Products with the brand name 8015 and the item number 16-886.

[0049] Example 1: A snow-melting bridge cable sheath material, the raw material dosage of the sheath material is as shown in Table 1, wherein the PE resin includes ultra-high molecular weight polyethylene and high-density polyethylene in a mass ratio of 1:1.5, the antioxidant is antioxidant 1010, the lubricant is polyethylene wax, the light stabilizer is UV-329, the snow-melting material is PAN nanofiber loaded with sodium chloride, the PAN nanofiber loaded with sodium chloride is prepared by Preparation Example 1, the black masterbatch is a commercially available product, and the preservative is prepared by the following method: 3g of nano titanium nitride and 2g of silicon dioxide are dispersed in an ethanol solution of KH570 formed by mixing 5ml of KH570, 22ml of ethanol and 2ml of deionized water, the pH is adjusted to 5 with acetic acid, the temperature is raised to 60°C for reaction for 2.5h, centrifuged, washed, dispersed in 20ml of anhydrous ethanol, 3ml of octadecyl methacrylate and 0.05g of 2,2-azobisisobutyronitrile are added, stirred at 60°C for 3h, filtered and dried to obtain a preservative.

[0050] The sheath material is made by the following method: PE resin, polyolefin elastomer, light stabilizer, antioxidant, lubricant, black masterbatch, snow melting material and preservative are uniformly mixed, and then extruded and granulated. The extrusion temperature is 210° C. and the screw speed is 450 Hz.

[0051] Table 1 Raw material dosage of snowmelt bridge cable sheath material Example 2: A bridge cable, which differs from Example 1 in that the amount of raw materials for the sheath material is as shown in Table 1, wherein the PE resin comprises ultra-high molecular weight polyethylene and high-density polyethylene in a mass ratio of 1:1, the antioxidant is antioxidant 168, the lubricant is calcium stearate, the light stabilizer is UV-329, the snow-melting material is PAN nanofiber loaded with sodium chloride, the PAN nanofiber loaded with sodium chloride is prepared by Preparation Example 2, the black masterbatch is a commercially available product, and the preservative is prepared by the following method: 3g of nano-titanium nitride and 2g of silicon dioxide are dispersed in an ethanol solution of KH570 formed by mixing 5ml of KH570, 22ml of ethanol and 2ml of deionized water, the pH is adjusted to 5 with acetic acid, the temperature is raised to 60°C for reaction for 2.5h, centrifuged, washed, dispersed in 20ml of anhydrous ethanol, 3ml of octadecyl methacrylate and 0.05g of 2,2-azobisisobutyronitrile are added, stirred at 60°C for 3h, filtered and dried to prepare the preservative.

[0052] The sheath material is made by the following method: PE resin, polyolefin elastomer, light stabilizer, antioxidant, lubricant, black masterbatch, snow melting material and preservative are uniformly mixed, and then extruded and granulated. The extrusion temperature is 190° C. and the screw speed is 500 Hz.

[0053] Example 3: A bridge cable, which differs from Example 1 in that the amount of raw materials for the sheath material is as shown in Table 1, wherein the PE resin comprises ultra-high molecular weight polyethylene and high-density polyethylene in a mass ratio of 1:1.3, the antioxidant is antioxidant 1076, the lubricant is paraffin, the light stabilizer is UV-329, the snow-melting material is PAN nanofiber loaded with sodium chloride, the PAN nanofiber loaded with sodium chloride is prepared by Preparation Example 1, the black masterbatch is a commercially available product, and the preservative is prepared by the following method: 3g of nano-titanium nitride and 2g of silicon dioxide are dispersed in an ethanol solution of KH570 formed by mixing 5ml of KH570, 22ml of ethanol and 2ml of deionized water, the pH is adjusted to 5 with acetic acid, the temperature is raised to 60°C for reaction for 2.5h, and after centrifugation and washing, it is dispersed in 20ml of anhydrous ethanol, 3ml of octadecyl methacrylate and 0.05g of 2,2-azobisisobutyronitrile are added, stirred at 60°C for 3h, filtered and dried to prepare the preservative.

[0054] The sheath material is made by the following method: PE resin, polyolefin elastomer, light stabilizer, antioxidant, lubricant, black masterbatch, snow melting material and preservative are uniformly mixed, and then extruded and granulated. The extrusion temperature is 200°C and the screw speed is 550Hz.

[0055] Example 4: A snow-melting bridge cable sheath material, which is different from Example 1 in that the PAN nanofiber loaded with sodium chloride is made from Preparation Example 3.

[0056] Example 5: A snow-melting bridge cable sheath material, which is different from Example 1 in that the PAN nanofiber loaded with sodium chloride is made from Preparation Example 4.

[0057] Example 6: A snow-melting bridge cable sheath material, which is different from Example 1 in that the PAN nanofibers loaded with sodium chloride are made from Preparation Example 5.

[0058] Example 7: A snow-melting bridge cable sheath material, which is different from Example 1 in that the PAN nanofibers loaded with sodium chloride are made from Preparation Example 6.

[0059] Example 8: A snow-melting bridge cable sheath material, which differs from Example 7 in that the PE resin includes ultra-high molecular weight polyethylene, high-density polyethylene and hydrophobically modified aerogel in a mass ratio of 1:1.5:0.3, and the hydrophobically modified aerogel is made by Preparation Example 7.

[0060] Example 9: A snow-melting bridge cable sheath material, which differs from Example 7 in that the PE resin includes ultra-high molecular weight polyethylene, high-density polyethylene and hydrophobically modified aerogel in a mass ratio of 1:1.5:0.15, and the hydrophobically modified aerogel is made by Preparation Example 8.

[0061] Example 10: A snow-melting bridge cable sheath material, which differs from Example 8 in that the hydrophobically modified aerogel is made from Preparation Example 9.

[0062] Example 11: A snow-melting bridge cable sheath material, which differs from Example 8 in that the hydrophobically modified aerogel is made from Preparation Example 10.

[0063] Example 12: A snow-melting bridge cable sheath material, which differs from Example 8 in that the hydrophobically modified aerogel is made from Preparation Example 11.

[0064] Example 13: A snow-melting bridge cable sheath material, which differs from Example 8 in that the hydrophobically modified aerogel is made from Preparation Example 12.

[0065] Example 14: A snow-melting bridge cable sheath material, which differs from Example 8 in that the black masterbatch is prepared by mixing polyethylene, polysiloxane and carbon black in a mass ratio of 1:1:0.5, kneading the mixture at 170°C, and then extruding and granulating the mixture; the polyethylene is a high-density polyethylene selected from Yanshan Petrochemical, model B5703; the polysiloxane is an ultra-high molecular weight polysiloxane selected from Dow Corning MBSI-002P; and the carbon black is N330.

[0066] Example 15: A snow-melting bridge cable sheath material, which differs from Example 8 in that the black masterbatch is prepared by mixing polyethylene, polysiloxane and carbon black in a mass ratio of 1:0.8:0.3, kneading the mixture at 170°C, and then extruding and granulating the mixture; the polyethylene is a high-density polyethylene selected from Yanshan Petrochemical, model B5703; the polysiloxane is an ultra-high molecular weight polysiloxane selected from Dow Corning MBSI-002P; and the carbon black is N330.

[0067] Comparative Example Comparative Example 1: A snow-melting bridge cable sheath material, which differs from Example 1 in that no snow-melting material is added.

[0068] Comparative Example 2: A snow-melting bridge cable sheath material, which differs from Example 1 in that the snow-melting material is sodium chloride.

[0069] Performance testing The sheath material was prepared according to the methods in the examples and comparative examples, and the performance of the sheath material was tested according to the following method. The test results are recorded in Table 2.

[0070] 1. Impact strength: The test is carried out in accordance with GB / T 1843-2008 "Determination of cantilever beam impact strength of plastics". The sample size is 10mm×80mm×4mm. When testing the impact strength at -60℃, the sample is placed at the test temperature for more than 2h in advance and then taken out for testing immediately.

[0071] 2. Tensile properties test: The test is carried out according to GB / T 1040.1-2018 "Determination of tensile properties of plastics Part 1: General principles", the specimen is type I, and the tensile rate is 50 mm / min.

[0072] 3. Bending performance test: Test according to GB / T 9341-2008 "Determination of bending properties of plastics", sample size 10mm×80mm×4mm.

[0073] 4. Ice-melting ability test: The ice-melting ability is tested using the test method in SHRP-H-332 "Handbook of Evaluation Methods for Chemical Deicing Agents". The test steps are as follows: Place 120 ml of deionized water in a cylindrical container, place it horizontally in a -10°C low-temperature freezer, and take it out after 3 hours for use; accurately weigh 5 g of sheath material and sprinkle it evenly on the homemade ice surface, place it in a -5°C low-temperature freezer and let it stand; use a syringe to extract the liquid at the bottom of the container every 10 minutes, and then immediately place it in a -5°C low-temperature freezer and continue to stand; inject the liquid in the syringe into a measuring cylinder and record the liquid volume.

[0074] Table 2 Performance test of sheath material It can be seen from the data in Table 2 that in Examples 1-3, PAN nanofibers loaded with sodium chloride are used as snow-melting materials, and the prepared sheath materials have a certain ice-melting ability and are not easy to cause frozen snow accumulation on the cable. Moreover, the sheath material has strong low-temperature impact resistance, is not easy to crack at low temperatures, and has excellent low-temperature resistance.

[0075] In Example 4, the sodium chloride loaded PAN nanofibers prepared in Preparation Example 3 were used. Compared with Example 1, no boron nitride nanosheets were added. It can be seen that the ice melting ability of the sheath material is reduced, but the mechanical strength such as notched impact strength is significantly reduced.

[0076] In Example 5, the sodium chloride loaded PAN nanofibers prepared in Preparation Example 4 were used. Compared with Preparation Example 1 in Example 1, no boron nitride nanosheets and polyurethane were added. It can be seen that the mechanical strength of the sheath material decreased and the ice melting ability decreased.

[0077] In Example 6, the sodium chloride loaded PAN nanofibers prepared in Preparation Example 5 were used. Compared with Example 1, no cellulose nanocrystals were added. It can be seen that the ice melting ability of the sheath material is not greatly affected, but the low temperature resistance and mechanical strength of the sheath material are affected.

[0078] In Example 7, the sodium chloride-loaded PAN nanofibers prepared in Preparation Example 6 are used. Compared with Example 1, trimethyltrichlorosilane is also used to vapor-deposit the sodium chloride-loaded PAN nanofibers. The sheath material prepared in Example 7 has enhanced low temperature resistance and bending resistance.

[0079] Compared with Example 7, Examples 8 and 9 further add hydrophobically modified polyvinyl alcohol aerogel to the PE resin, and the hydrophobically modified polyvinyl alcohol aerogel is prepared from Preparation Example 7 and Preparation Example 8, respectively. The sheath materials prepared from Examples 8 and 9 have enhanced ice melting ability and improved resistance to low-temperature cracking.

[0080] Compared with Example 8, Example 10 uses the hydrophobically modified polyvinyl alcohol aerogel prepared in Preparation Example 9, and compared with Preparation Example 7, no titanium carbide is added. It can be seen that the mechanical strength of the sheath material is reduced, and the other properties do not change much.

[0081] Compared with Example 7, Example 11 uses the hydrophobically modified polyvinyl alcohol aerogel prepared in Preparation Example 11, in which aramid nanofibers are not added. The mechanical properties such as bending strength of the sheath material prepared in Example 11 are reduced.

[0082] In Example 12, the hydrophobically modified polyvinyl alcohol aerogel prepared in Preparation Example 11 was used, and the aerogel was not impregnated with the graphene oxide solution. Compared with Example 7, the mechanical strength of the sheath material decreased, and the ice-melting effect was slightly weakened.

[0083] In Example 13, the hydrophobically modified polyvinyl alcohol aerogel prepared in Preparation Example 12 was used. Compared with Example 8, it was not immersed in an aqueous solution of hydrogen iodide. It can be seen that the mechanical strength of the sheath material was weakened, indicating that the unreduced graphene oxide may be unevenly dispersed in the sheath material, thereby affecting the mechanical strength of the material.

[0084] Compared with Example 8, Examples 14 and 15 also use polysiloxane, polyethylene and carbon black to prepare black masterbatch, and it can be seen that the mechanical strength and ice-melting ability of the material are slightly enhanced.

[0085] In Comparative Example 1, no snow-melting material is added. It can be seen that the mechanical strength of the sheath material made therefrom does not change much, but the ice-melting ability is significantly reduced compared with Example 1.

[0086] In Comparative Example 2, sodium chloride is used as the snow-melting material. It can be seen that its mechanical strength decreases and the snow-melting speed is fast, such as a better slow-release effect.

[0087] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A snow-melting bridge cable sheath material, characterized in that: The sheath material comprises the following raw materials in parts by weight: 100 parts of PE resin, 8-15 parts of polyolefin elastomer, 0.1-0.4 parts of light stabilizer, 0.3-0.5 parts of antioxidant, 1.5-2 parts of lubricant, 5-6 parts of black masterbatch, 4-8 parts of snow-melting material, and 2-5 parts of preservative; the snow-melting material is PAN nanofiber loaded with sodium chloride.

2. The snow-melting bridge cable sheath material according to claim 1, characterized in that: The sodium chloride-loaded PAN nanofiber is prepared by the following method: Dissolving polyurethane, adding PVP and boron nitride nanosheets to obtain a core layer liquid with a polyurethane concentration of 18-20wt%, and a mass ratio of polyurethane, PVP and boron nitride nanosheets of 1:1.5-2:0.2-0.3; Dispersing cellulose nanocrystals in DMF, adding PAN powder, and mixing evenly to prepare a shell liquid with a PAN concentration of 14-15wt%, and a mass ratio of cellulose nanocrystals to PAN of 0.1-0.2:1; The core layer liquid and the shell layer liquid were coaxially electrospun to obtain nanofibers, which were immersed in deionized water and dried to obtain porous PAN nanofibers. The core-shell solution flow rate ratio was 5:

1. The porous PAN nanofibers are immersed in a saturated sodium chloride solution, heated to 70-80° C., stirred for 5-6 hours, and dried to a constant weight, wherein the mass ratio of the porous PAN nanofibers to the sodium chloride is 15-20:

20.

3. The snow-melting bridge cable sheath material according to claim 2, characterized in that: The sodium chloride-loaded PAN nanofibers are pretreated by methyltrichlorosilane vapor deposition.

4. The snow-melting bridge cable sheath material according to claim 1, characterized in that: The PE resin includes ultra-high molecular weight polyethylene and high density polyethylene in a mass ratio of 1:1-1.

5.

5. The snow-melting bridge cable sheath material according to claim 4, characterized in that: The PE resin is further added with hydrophobically modified polyvinyl alcohol aerogel, and the mass ratio of the hydrophobically modified polyvinyl alcohol aerogel to high-density polyethylene is 0.1-0.2:

1.

6. The snow-melting bridge cable sheath material according to claim 5, characterized in that: The hydrophobically modified polyvinyl alcohol aerogel is prepared by the following method: Dispersing titanium carbide in deionized water, ultrasonically dispersing, adding aramid nanofibers, and ultrasonically dispersing to obtain a dispersion, wherein the mass ratio of titanium carbide to aramid nanofibers is 0.1-0.2:2; Adding polyvinyl alcohol to the dispersion, stirring at 90-100° C. for 2-3 hours and then freezing, thawing and immersing in a potassium hydroxide solution, taking out, and freeze-drying to obtain an aerogel, wherein the mass ratio of polyvinyl alcohol to aramid fiber is 3-4:1; The aerogel is immersed in a graphene oxide solution, filtered and dried at 60-70° C. for 22-24 hours, immersed in a hydrogen iodide aqueous solution, kept warm at 70-80° C. for 12-15 hours, filtered, washed and dried to obtain a hydrophobically modified polyvinyl alcohol aerogel.

7. The snow-melting bridge cable sheath material according to claim 1, characterized in that: The black masterbatch is prepared by mixing and granulating polyethylene, polysiloxane and carbon black in a mass ratio of 1:0.8-1:0.3-0.

5.

8. The snow-melting bridge cable sheath material according to claim 1, characterized in that: The preservative is prepared by the following method: Nano titanium nitride and silicon dioxide are dispersed in an ethanol solution of KH570, the pH is adjusted to 4-5, the temperature is raised to 60-65°C for reaction for 2-2.5 hours, the solution is dispersed in anhydrous ethanol after centrifugation and washing, octadecyl methacrylate and 2,2-azobisisobutyronitrile are added, the solution is stirred at 60-65°C for 2-3 hours, filtered and dried to obtain a preservative.

9. The snow-melting bridge cable sheath material according to claim 2, characterized in that: The antioxidant is selected from at least one of antioxidant 1010, antioxidant 168 and antioxidant 1076; The lubricant is selected from at least one of stearamide, calcium stearate, paraffin wax, polyethylene wax and acrylic wax.

10. The method for preparing the snow-melting bridge cable sheath material according to any one of claims 1 to 9, characterized in that: The following steps are involved: PE resin, polyolefin elastomer, light stabilizer, antioxidant, lubricant, black masterbatch, snow melting material and preservative are uniformly mixed and then extruded and granulated. The extrusion temperature is 190-210°C and the screw speed is 450-550Hz.

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