Anti-aging cable and preparation method thereof

Abstract

The invention relates to the technical field of cable materials, in particular to an anti-aging cable and a preparation method thereof. The anti-aging cable comprises a sheath and a plurality of cable bodies arranged in the sheath in a penetrating mode. The sheath is prepared from the following raw materials in parts by weight: 90-110 parts of polyethylene, 10-20 parts of maleic anhydride grafted polyethylene, 5-10 parts of a modified anti-ultraviolet agent and 1-5 parts of a cross-linking agent; the modified anti-ultraviolet agent is prepared by mixing double-bond lignin powder and modified sodium lignin sulfonate powder according to the weight ratio of (1 to 3): (5 to 10). Compared with a traditional polyethylene cable, the anti-aging cable has the advantages that the mechanical property, the insulating property or the anti-aging property are improved to a certain extent, and the anti-aging cable can be widely applied to the field of anti-aging cables.

Description

Technical Field

[0001] The present invention relates to the technical field of cable materials, and particularly relates to an anti-aging cable and a preparation method thereof. Background Art

[0002] The electric power industry is an important industry related to the national economy and people's livelihood. An extremely important part of it is the transmission of electric power. The main tool for electric power transmission is the cable. Therefore, the protection of the cable is also an indispensable link. As the first layer of protection for the cable to resist external damage, the performance of the cable sheath is related to a series of issues such as electric power transmission and electricity use safety. This requires that the cable sheath must have good performance such as mechanical performance, electrical insulation performance, anti-aging performance, etc., to ensure the successful construction of such a high-standard electric energy transmission channel.

[0003] In the wire and cable industry, the polymers used as sheath materials include polyethylene (PE), polyvinyl chloride (PVC), polyurethane, thermoplastic elastomer, thermoplastic polyurethane rubber; among them, polyethylene, especially high-density polyethylene (HDPE), has become one of the most widely used sheath materials due to its excellent electrical insulation performance, good comprehensive mechanical properties, processing performance, and environmental protection.

[0004] Although HDPE has many advantages when used as a sheath material, it has some disadvantages itself, which greatly restricts its development in the cable field. Nano-fillers have small size effect, surface and interface effect, macroscopic quantum tunneling effect and quantum size effect. At present, nano-fillers are often used to enhance the mechanical properties, electrical properties, barrier properties, anti-aging properties, heat resistance properties, flame retardant properties, etc. of polymer matrix materials.

[0005] Patent technical literature CN114933756A discloses an anti-aging polyethylene material, a preparation method thereof and a cable. The anti-aging polyethylene material of this invention includes the following raw materials: polyethylene, maleic anhydride grafted polyethylene, and an organic-inorganic composite agent. The organic-inorganic composite agent is an anti-ultraviolet metal oxide modified by a titanate-organosilicon composition. The cable prepared by this invention has excellent anti-ultraviolet aging performance.

[0006] Patent technical document CN116589778B discloses an aging-resistant cable protective cover, a preparation method thereof and an aging-resistant cable. The aging-resistant cable protective cover of the invention comprises the following raw materials: a polymer base material, expandable graphite, nano-titanium dioxide, reflective particles, and an organic ultraviolet absorber; the reflective particles comprise nano-calcium carbonate and nano-barium sulfate; the particle size ratio of nano-titanium dioxide: nano-calcium carbonate: nano-barium sulfate is (5-9):(2-3):1; the cable of the invention improves the absorption effect of nano-titanium dioxide on ultraviolet rays and reduces the aging effect of ultraviolet rays on the protective cover.

[0007] However, with the continuous emergence of various application environments, the performance of cables has gradually been unable to meet the needs of daily production and life. Summary of the invention

[0008] In view of this, the object of the present invention is to provide an aging-resistant cable and a preparation method thereof, and to provide a cable with excellent insulation performance and aging-resistant performance.

[0009] Based on the above purpose, the present invention provides an aging-resistant cable, including a sheath and a plurality of cables inserted into the sheath;

[0010] The sheath is composed of the following raw materials in parts by weight: 90-110 parts of polyethylene, 10-20 parts of maleic anhydride grafted polyethylene, 5-10 parts of modified anti-ultraviolet agent and 1-5 parts of cross-linking agent;

[0011] The modified anti-ultraviolet agent is a mixture of double-bonded lignin powder and modified sodium lignin sulfonate powder in a weight ratio of 1-3:5-10;

[0012] The preparation steps of the double-bonded lignin powder are as follows:

[0013] S11: adding alkali lignin to anhydrous ethanol, stirring magnetically at room temperature for 2 hours, then adding sodium hydroxide solution and zinc nitrate hexahydrate solution, and then heating the mixture in a water bath at 60-70°C for 30 minutes. After the reaction is completed, centrifuging, washing, and drying, placing the obtained solid in a tubular furnace, calcining at 500-600°C for 2-3 hours under a nitrogen atmosphere, cooling to room temperature, crushing, and sieving to obtain modified lignin powder;

[0014] S12: dissolving the modified lignin powder in a sodium hydroxide solution, adding allyl glycidyl ether, reacting at room temperature for 24 hours, precipitating, washing, and drying to obtain a double-bonded lignin powder;

[0015] The preparation steps of the modified sodium lignin sulfonate powder are as follows:

[0016] S21: Mix sodium lignosulfonate, acrylamide, N,N'-methylenebis(acrylamide) and deionized water, and dissolve them by magnetic stirring to obtain a mixed solution; subsequently, dissolve potassium persulfate in deionized water to obtain a potassium persulfate solution; mix the mixed solution and the potassium persulfate solution, shake well, then add TEMED, and react at 40 - 45 °C to obtain a sodium lignosulfonate hydrogel;

[0017] S22: Immerse the sodium lignosulfonate hydrogel in deionized water for 12 h, then immerse the soaked hydrogel in a mixed solution of ferrous sulfate heptahydrate and ferric chloride hexahydrate for 8 - 10 h. After the immersion, wash with distilled water, then transfer it to a sodium hydroxide solution and immerse it for 7 - 8 h. Wash until neutral, soak in distilled water for 12 h, dehydrate at room temperature for 2 - 3 d, dry to a constant weight, and crush to obtain modified sodium lignosulfonate powder;

[0018] In step S11, the dosage ratio of the alkali lignin, absolute ethanol, sodium hydroxide solution, and zinc nitrate hexahydrate solution is 1 - 3 g: 40 - 50 ml: 10 - 15 ml: 20 - 25 ml;

[0019] In step S12, the dosage ratio of the modified lignin, sodium hydroxide solution, and allyl glycidyl ether is 2 - 3 g: 50 - 70 mL: 10 - 15 mL;

[0020] In step S21, the dosage ratio of the sodium lignosulfonate, acrylamide, N,N'-methylenebis(acrylamide), deionized water, potassium persulfate, and TEMED is 3 - 5 g: 10 - 15 g: 0.2 - 0.3 g: 120 - 180 g: 2 - 2.5 g: 0.4 - 0.6 mL;

[0021] In step 22, the dosage ratio of the sodium lignosulfonate hydrogel, the mixed solution, and the sodium hydroxide solution is 5 - 10 g: 50 - 100 mL: 50 mL;

[0022] In the mixed solution in step 22, the molar ratio of ferrous sulfate heptahydrate to ferric chloride hexahydrate is 1:1.4.

[0023] Preferably, the polyethylene is high - density polyethylene, and its melt index (190 °C, 2.16 kg) is 0.8 g / 10 min.

[0024] Preferably, the density of the maleic anhydride - grafted polyethylene is 0.92 g / ml (25 °C).

[0025] Preferably, the cross - linker is dicumyl peroxide.

[0026] Preferably, the concentration of the sodium hydroxide solution in step S11 is 8 mol / L.

[0027] Preferably, the concentration of the zinc nitrate hexahydrate solution in step S11 is 0.5 mol / L.

[0028] Preferably, the washing in step S12 is to wash 3 times each with deionized water and absolute ethanol.

[0029] Preferably, the concentration of the sodium hydroxide solution in step S12 is 2 mol / L.

[0030] Preferably, the concentration of the sodium hydroxide solution in step 22 is 1 mol / L.

[0031] Furthermore, the present invention also provides a preparation method of an anti-aging cable, and the specific preparation steps are as follows:

[0032] Mix polyethylene, maleic anhydride grafted polyethylene, modified anti-ultraviolet agent and crosslinking agent, stir evenly to obtain a mixture, and then carry out melt extrusion and molding to obtain a sheath. Insert four cables into the sheath to obtain the anti-aging cable.

[0033] Preferably, the extrusion temperature of the extruder is 150 °C in the first stage, 155 °C in the second stage, 160 °C in the third stage, 160 °C in the fourth stage, 160 °C in the fifth stage, 160 °C in the sixth stage, 160 °C in the seventh stage, 160 °C in the eighth stage, and the screw speed is 120 r / min.

[0034] The beneficial effects of the present invention: The anti-aging cable of the present invention has excellent mechanical strength and bending strength and good insulation performance. Most importantly, it has excellent anti-aging performance and can meet the use in various harsh environments.

[0035] The anti-aging cable of the present invention, through the good anti-ultraviolet performance and insulation performance of lignin and sodium lignosulfonate itself and the mutual coordination and promotion between the two, makes the obtained anti-aging cable superior to traditional polyethylene cables in terms of both mechanical properties, insulation properties and anti-aging properties.

[0036] The anti-aging cable of the present invention, by loading zinc oxide nanoparticles on the surface of lignin and Fe 3 O 4 nanoparticles on the surface of sodium lignosulfonate, improves the mechanical properties, insulation properties and anti-aging properties of the anti-aging cable to a certain extent. Specific Embodiments

[0037] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following further elaborates on the present invention in conjunction with specific embodiments.

[0038] In the mixed solution of ferrous sulfate heptahydrate and ferric chloride hexahydrate in the present invention, the molar ratio of ferrous sulfate heptahydrate to ferric chloride hexahydrate is 1:1.4.

[0039] Example 1: An anti-aging cable, and the specific preparation steps are as follows:

[0040] (1) Mix 3 g of sodium lignosulfonate, 10 g of acrylamide, 0.2 g of N,N-methylenebis(acrylamide) and 100 g of deionized water, and dissolve them by magnetic stirring to obtain a mixed solution; subsequently, dissolve 2 g of potassium persulfate in 20 g of deionized water to obtain a potassium persulfate solution; mix the mixed solution and the potassium persulfate solution, shake well, then add 0.4 mL of TEMED, and react at 40 °C to obtain sodium lignosulfonate hydrogel;

[0041] (2) Immerse 5 g of sodium lignosulfonate hydrogel in 100 mL of deionized water for 12 h, then immerse it in a mixed solution of 50 mL of ferrous sulfate heptahydrate and ferric chloride hexahydrate for 8 h. After the immersion, wash it with distilled water, then transfer it to 50 mL of 1 mol / L sodium hydroxide solution, immerse it for 7 h, wash it until neutral, and immerse it in distilled water for 12 h. Dehydrate at room temperature for 2 - 3 d, dry it at 60 °C to constant weight, and crush it to obtain modified sodium lignosulfonate powder;

[0042] (3) Add 1 g of alkali lignin to 40 ml of absolute ethanol, stir magnetically at room temperature for 2 h, then add 10 ml of 8 mol / L sodium hydroxide solution and 20 ml of 0.5 mol / L zinc nitrate hexahydrate solution. Then place the mixture in a water bath at 60 °C and heat it for 30 min. After the reaction, centrifuge it, wash it 3 times with deionized water and absolute ethanol respectively, dry it, place the obtained solid in a tube furnace, calcine it at 500 °C for 2 h in a nitrogen atmosphere, cool it to room temperature, crush it, and sieve it to obtain modified lignin powder;

[0043] (4) Dissolve 2 g of modified lignin powder in 50 mL of 2 mol / L sodium hydroxide solution, add 10 mL of allyl glycidyl ether, react at room temperature for 24 h, then precipitate the mixture solution with acetone. Wash the precipitated product with acetone repeatedly for 5 times, and dry it under vacuum at 60 °C for 48 h to obtain double-bonded lignin powder;

[0044] (5) Mix 1 g of double-bonded lignin powder and 5 g of modified sodium lignosulfonate powder, and disperse them evenly to obtain a modified anti-ultraviolet agent;

[0045] (6) Mix 90 g of polyethylene, 10 g of maleic anhydride grafted polyethylene, 5 g of modified ultraviolet stabilizer, and 1 g of diisopropylbenzene peroxide, stir evenly to obtain a mixture, and then carry out melt extrusion to obtain a sheath. Among them, the temperature of the extruder is: the first stage is 150 °C, the second stage is 155 °C, the third stage is 160 °C, the fourth stage is 160 °C, the fifth stage is 160 °C, the sixth stage is 160 °C, the seventh stage is 160 °C, the eighth stage is 160 °C, the screw speed is 120 r / min. Insert four cables into the sheath to obtain the aging-resistant cable.

[0046] Example 2: An aging-resistant cable, and the specific preparation steps are as follows:

[0047] (1) Mix 4 g of sodium lignosulfonate, 12.5 g of acrylamide, 0.25 g of N,N-methylenebis(acrylamide), and 130 g of deionized water, stir and dissolve magnetically to obtain a mixed solution; then dissolve 2.3 g of potassium persulfate in 25 g of deionized water to obtain a potassium persulfate solution; mix the mixed solution and the potassium persulfate solution, shake well, then add 0.5 mL of TEMED, and react at 43 °C to obtain sodium lignosulfonate hydrogel.

[0048] (2) Immerse 7.5 g of sodium lignosulfonate hydrogel in 150 mL of deionized water and soak for 12 h, then immerse it in a mixed solution of 80 mL of ferrous sulfate heptahydrate and ferric chloride hexahydrate and soak for 9 h. After the soaking is completed, wash with distilled water, then transfer it to 50 mL of 1 mol / L sodium hydroxide solution and soak for 7 h, wash until neutral, soak in distilled water for 12 h, dehydrate at room temperature for 2 d, dry at 63 °C to constant weight, and crush to obtain modified sodium lignosulfonate powder.

[0049] (3) Add 2 g of alkali lignin to 45 ml of absolute ethanol, stir magnetically at room temperature for 2 h, then add 13 ml of 8 mol / L sodium hydroxide solution and 23 ml of 0.5 mol / L zinc nitrate hexahydrate solution, and then place the mixture in a water bath at 65 °C and heat for 30 min. After the reaction is completed, centrifuge, wash 3 times with deionized water and absolute ethanol respectively, dry, place the obtained solid in a tube furnace, calcine in a nitrogen atmosphere at 550 °C for 3 h, cool to room temperature, crush, and sieve to obtain modified lignin powder.

[0050] (4) Dissolve 2.5 g of modified lignin powder in 60 mL of 2 mol / L sodium hydroxide solution, add 13 mL of allyl glycidyl ether, react at room temperature for 24 h, then precipitate the mixture solution with acetone, wash the precipitated product with acetone repeatedly 5 times, and vacuum dry at 60 °C for 48 h to obtain double-bonded lignin powder.

[0051] (5) Mix 2 g of double-bonded lignin powder and 8 g of modified lignosulfonate powder evenly to obtain a modified anti-ultraviolet agent;

[0052] (6) Mix 100 g of polyethylene, 15 g of maleic anhydride grafted polyethylene, 7.5 g of the modified anti-ultraviolet agent, and 3 g of diisopropylbenzene peroxide evenly, and then carry out melt extrusion to obtain a sheath. Among them, the temperature of the extruder is: the first section is 150 °C, the second section is 155 °C, the third section is 160 °C, the fourth section is 160 °C, the fifth section is 160 °C, the sixth section is 160 °C, the seventh section is 160 °C, the eighth section is 160 °C, and the screw speed is 120 r / min. Insert four cables into the sheath to obtain an anti-aging cable.

[0053] Example 3: An anti-aging cable, and the specific preparation steps are as follows:

[0054] (1) Mix 5 g of lignosulfonate, 15 g of acrylamide, 0.3 g of N,N-methylenebis(acrylamide), and 150 g of deionized water, and dissolve them by magnetic stirring to obtain a mixed solution; then dissolve 2.5 g of potassium persulfate in 30 g of deionized water to obtain a potassium persulfate solution; mix the mixed solution and the potassium persulfate solution, shake well, then add 0.6 mL of TEMED, and react at 45 °C to obtain a lignosulfonate hydrogel;

[0055] (2) Immerse 10 g of the lignosulfonate hydrogel in 200 mL of deionized water for 12 h, then immerse it in a mixed solution of 100 mL of ferrous sulfate heptahydrate and ferric chloride hexahydrate for 10 h. After the immersion is completed, wash it with distilled water, then transfer it to 50 mL of 1 mol / L sodium hydroxide solution, immerse it for 8 h, wash it to neutrality, and immerse it in distilled water for 12 h. Dehydrate at room temperature for 3 d, dry it at 65 °C to constant weight, and crush it to obtain modified lignosulfonate powder;

[0056] (3) Add 3 g of alkali lignin to 50 ml of absolute ethanol, stir magnetically at room temperature for 2 h, then add 15 ml of 8 mol / L sodium hydroxide solution and 25 ml of 0.5 mol / L zinc nitrate hexahydrate solution, and then place the mixture in a water bath at 70 °C and heat for 30 min. After the reaction is completed, centrifuge, wash it 3 times with deionized water and absolute ethanol respectively, dry it, place the obtained solid in a tube furnace, calcine it at 600 °C for 3 h in a nitrogen atmosphere, cool it to room temperature, crush it, and sieve it to obtain modified lignin powder;

[0057] (4) Dissolve 3 g of modified lignin powder in 70 mL of 2 mol / L sodium hydroxide solution, add 15 mL of allyl glycidyl ether, react at room temperature for 24 h, then precipitate the mixture solution with acetone. The precipitated product is washed repeatedly with acetone 5 times and dried in vacuum at 60 °C for 48 h to obtain double-bonded lignin powder;

[0058] (5) Mix 3 g of double-bonded lignin powder and 10 g of modified lignosulfonate powder and disperse them evenly to obtain a modified ultraviolet absorber;

[0059] (6) Mix 110 g of polyethylene, 20 g of maleic anhydride grafted polyethylene, 10 g of modified ultraviolet absorber and 5 g of diisopropylbenzene peroxide, stir evenly to obtain a mixture, and then carry out melt extrusion to obtain a sheath. Among them, the temperature of the extruder is: the first stage is 150 °C, the second stage is 155 °C, the third stage is 160 °C, the fourth stage is 160 °C, the fifth stage is 160 °C, the sixth stage is 160 °C, the seventh stage is 160 °C, the eighth stage is 160 °C, and the screw speed is 120 r / min. Insert four cables into the sheath to obtain an aging-resistant cable.

[0060] Comparative Example 1: An aging-resistant cable, which is different from Example 2 in that it does not carry Fe 3 O 4 nanoparticles. The specific preparation steps are as follows:

[0061] (1) Mix 4 g of lignosulfonate, 12.5 g of acrylamide, 0.25 g of N,N-methylenebis(acrylamide) and 130 g of deionized water, stir and dissolve magnetically to obtain a mixed solution; then dissolve 2.3 g of potassium persulfate in 25 g of deionized water to obtain a potassium persulfate solution; mix the mixed solution and the potassium persulfate solution, shake well, then add 0.5 mL of TEMED, and react at 43 °C to obtain lignosulfonate hydrogel. Wash and dry to constant weight, and crush to obtain lignosulfonate powder;

[0062] (2) Add 2 g of alkali lignin to 45 ml of absolute ethanol, stir magnetically at room temperature for 2 h, then add 13 ml of 8 mol / L sodium hydroxide solution and 23 ml of 0.5 mol / L zinc nitrate hexahydrate solution. Then place the mixture in a water bath at 65 °C and heat for 30 min. After the reaction is completed, centrifuge, wash 3 times with deionized water and absolute ethanol respectively, dry, place the obtained solid in a tubular furnace, calcine at 550 °C for 3 h in a nitrogen atmosphere, cool to room temperature, crush, and sieve to obtain modified lignin powder;

[0063] (3) Dissolve 2.5 g of modified lignin powder in 60 mL of 2 mol / L sodium hydroxide solution, add 13 mL of allyl glycidyl ether, react at room temperature for 24 h, then precipitate the mixture solution with acetone. The precipitated product is washed repeatedly with acetone 5 times and dried in vacuum at 60 °C for 48 h to obtain double-bonded lignin powder;

[0064] (4) Mix 2 g of double-bonded lignin powder and 8 g of sodium lignosulfonate powder evenly to obtain a modified UV absorber;

[0065] (5) Mix 100 g of polyethylene, 15 g of maleic anhydride grafted polyethylene, 7.5 g of modified UV absorber and 3 g of diisopropylbenzene peroxide, stir evenly to obtain a mixture, and then carry out melt extrusion to obtain a sheath. Among them, the temperature of the extruder is: the first stage is 150 °C, the second stage is 155 °C, the third stage is 160 °C, the fourth stage is 160 °C, the fifth stage is 160 °C, the sixth stage is 160 °C, the seventh stage is 160 °C, the eighth stage is 160 °C, and the screw speed is 120 r / min. Insert four cables into the sheath to obtain an aging-resistant cable.

[0066] Comparative Example 2: An aging-resistant cable, which is different from Example 2 in that the sodium lignosulfonate hydrogel is broken into powder and then impregnated. The specific preparation steps are as follows:

[0067] (1) Mix 4 g of sodium lignosulfonate, 12.5 g of acrylamide, 0.25 g of N,N-methylenebis(acrylamide) and 130 g of deionized water, stir magnetically to dissolve to obtain a mixed solution; then dissolve 2.3 g of potassium persulfate in 25 g of deionized water to obtain a potassium persulfate solution; mix the mixed solution and the potassium persulfate solution, shake well, then add 0.5 mL of TEMED, and react at 43 °C to obtain sodium lignosulfonate hydrogel, wash, dry, and break to obtain sodium lignosulfonate powder;

[0068] (2) Immerse 7.5 g of sodium lignosulfonate powder in 150 mL of deionized water for 12 h, then immerse it in a mixed solution of 80 mL of ferrous sulfate heptahydrate and ferric chloride hexahydrate for 9 h. After the immersion is completed, wash with distilled water, then transfer it to 50 mL of 1 mol / L sodium hydroxide solution for 7 h, wash until neutral, and immerse in distilled water for 12 h, dehydrate at room temperature for 2 d, and dry at 63 °C to constant weight, and break to obtain modified sodium lignosulfonate powder;

[0069] (3) Add 2 g of alkali lignin to 45 ml of absolute ethanol, stir magnetically at room temperature for 2 h, then add 13 ml of 8 mol / L sodium hydroxide solution and 23 ml of 0.5 mol / L zinc nitrate hexahydrate solution. Then place the mixture in a water bath at 65 °C and heat for 30 min. After the reaction is completed, centrifuge, wash 3 times each with deionized water and absolute ethanol, dry, place the obtained solid in a tubular furnace, calcine at 550 °C for 3 h in a nitrogen atmosphere, cool to room temperature, crush, and sieve to obtain modified lignin powder;

[0070] (4) Dissolve 2.5 g of modified lignin powder in 60 mL of 2 mol / L sodium hydroxide solution, add 13 mL of allyl glycidyl ether, react at room temperature for 24 h, then precipitate the mixture solution with acetone. The precipitated product is washed repeatedly with acetone 5 times and dried in vacuo at 60 °C for 48 h to obtain double-bonded lignin powder;

[0071] (5) Mix 2 g of double-bonded lignin powder and 8 g of modified lignosulfonate powder, disperse evenly to obtain a modified UV absorber;

[0072] (6) Mix 100 g of polyethylene, 15 g of maleic anhydride grafted polyethylene, 7.5 g of modified UV absorber and 3 g of diisopropylbenzene peroxide, stir evenly to obtain a mixture, and then carry out melt extrusion to obtain a sheath. Among them, the extruder temperature is: the first section is 150 °C, the second section is 155 °C, the third section is 160 °C, the fourth section is 160 °C, the fifth section is 160 °C, the sixth section is 160 °C, the seventh section is 160 °C, the eighth section is 160 °C, and the screw speed is 120 r / min. Insert four cables into the sheath to obtain an aging-resistant cable.

[0073] Comparative Example 3: An aging-resistant cable, which is different from Example 2 in that lignosulfonate is replaced by lignin. The specific preparation steps are as follows:

[0074] (1) Mix 4 g of lignin, 12.5 g of acrylamide, 0.25 g of N,N-methylenebis(acrylamide) and 130 g of deionized water, stir magnetically to dissolve to obtain a mixed solution; then dissolve 2.3 g of potassium persulfate in 25 g of deionized water to obtain a potassium persulfate solution; mix the mixed solution and the potassium persulfate solution, shake well, and then add 0.5 mL of TEMED, and react at 43 °C to obtain lignin hydrogel;

[0075] (2) Immerse 7.5 g of lignin hydrogel in 150 mL of deionized water for 12 h. Subsequently, immerse it in a mixed solution of 80 mL of ferrous sulfate heptahydrate and ferric chloride hexahydrate for 9 h. After the immersion, wash it with distilled water, then transfer it to 50 mL of 1 mol / L sodium hydroxide solution, immerse it for 7 h, wash it until neutral, and immerse it in distilled water for 12 h. Dehydrate it at room temperature for 2 d, dry it at 63 °C to constant weight, and crush it to obtain modified lignin powder;

[0076] (3) Add 2 g of alkali lignin to 45 ml of anhydrous ethanol and stir magnetically at room temperature for 2 h. Subsequently, add 13 ml of 8 mol / L sodium hydroxide solution and 23 ml of 0.5 mol / L zinc nitrate hexahydrate solution. Then place the mixture in a water bath at 65 °C and heat it for 30 min. After the reaction, centrifuge it, wash it 3 times each with deionized water and anhydrous ethanol, dry it, place the obtained solid in a tube furnace, calcine it in a nitrogen atmosphere at 550 °C for 3 h, cool it to room temperature, crush it, and screen it to obtain lignin powder loaded with zinc oxide;

[0077] (4) Dissolve 2.5 g of lignin powder loaded with zinc oxide in 60 mL of 2 mol / L sodium hydroxide solution, add 13 mL of allyl glycidyl ether, react at room temperature for 24 h, then precipitate the mixture solution with acetone. The precipitated product is washed repeatedly with acetone 5 times and vacuum dried at 60 °C for 48 h to obtain double-bonded lignin powder;

[0078] (5) Mix 2 g of double-bonded lignin powder and 8 g of modified lignin powder and disperse them evenly to obtain a modified ultraviolet absorber;

[0079] (6) Mix 100 g of polyethylene, 15 g of maleic anhydride grafted polyethylene, 7.5 g of modified ultraviolet absorber, and 3 g of diisopropylbenzene peroxide, stir evenly to obtain a mixture, and then carry out melt extrusion to obtain a sheath. Among them, the temperature of the extruder is: the first stage is 150 °C, the second stage is 155 °C, the third stage is 160 °C, the fourth stage is 160 °C, the fifth stage is 160 °C, the sixth stage is 160 °C, the seventh stage is 160 °C, the eighth stage is 160 °C, and the screw speed is 120 r / min. Insert four cables into the sheath to obtain an aging-resistant cable.

[0080] Comparative Example 4: An aging-resistant cable, which is different from Example 2 in that the lignin does not carry zinc oxide nanoparticles. The specific preparation steps are as follows:

[0081] (1) Mix 4 g of sodium lignosulfonate, 12.5 g of acrylamide, 0.25 g of N,N-methylenebis(acrylamide) and 130 g of deionized water, and dissolve them by magnetic stirring to obtain a mixed solution; subsequently, dissolve 2.3 g of potassium persulfate in 25 g of deionized water to obtain a potassium persulfate solution; mix the mixed solution and the potassium persulfate solution, shake well, then add 0.5 mL of TEMED, and react at 43 °C to obtain sodium lignosulfonate hydrogel;

[0082] (2) Immerse 7.5 g of sodium lignosulfonate hydrogel in 150 mL of deionized water for 12 h, then immerse it in a mixed solution of 80 mL of ferrous sulfate heptahydrate and ferric chloride hexahydrate for 9 h. After the immersion, wash it with distilled water, then transfer it to 50 mL of 1 mol / L sodium hydroxide solution, immerse it for 7 h, wash it to neutrality, and immerse it in distilled water for 12 h. Dehydrate it at room temperature for 2 d, dry it at 63 °C to constant weight, and crush it to obtain modified sodium lignosulfonate powder;

[0083] (3) Dissolve 2.5 g of lignin powder in 60 mL of 2 mol / L sodium hydroxide solution, add 13 mL of allyl glycidyl ether, react at room temperature for 24 h, then precipitate the mixture solution with acetone. The precipitated product is washed repeatedly with acetone 5 times and dried in vacuo at 60 °C for 48 h to obtain double-bonded lignin powder;

[0084] (4) Mix 2 g of double-bonded lignin powder and 8 g of modified sodium lignosulfonate powder, and disperse them evenly to obtain a modified ultraviolet absorber;

[0085] (5) Mix 100 g of polyethylene, 15 g of maleic anhydride grafted polyethylene, 7.5 g of modified ultraviolet absorber and 3 g of diisopropylbenzene peroxide, stir evenly to obtain a mixture, and then carry out melt extrusion to obtain a sheath. Among them, the temperature of the extruder is: the first section is 150 °C, the second section is 155 °C, the third section is 160 °C, the fourth section is 160 °C, the fifth section is 160 °C, the sixth section is 160 °C, the seventh section is 160 °C, the eighth section is 160 °C, and the screw speed is 120 r / min. Insert four cables into the sheath to obtain an aging-resistant cable.

[0086] Comparative Example 5: An aging-resistant cable, which is different from Example 2 in that the lignin is not subjected to double-bonding treatment. The specific preparation steps are as follows:

[0087] (1) Mix 4 g of sodium lignosulfonate, 12.5 g of acrylamide, 0.25 g of N,N - methylenebis(acrylamide) and 130 g of deionized water, and dissolve them by magnetic stirring to obtain a mixed solution; subsequently, dissolve 2.3 g of potassium persulfate in 25 g of deionized water to obtain a potassium persulfate solution; mix the mixed solution and the potassium persulfate solution, shake well, then add 0.5 mL of TEMED, and react at 43 °C to obtain sodium lignosulfonate hydrogel;

[0088] (2) Immerse 7.5 g of sodium lignosulfonate hydrogel in 150 mL of deionized water for 12 h, then immerse it in a mixed solution of 80 mL of ferrous sulfate heptahydrate and ferric chloride hexahydrate for 9 h. After the immersion, wash it with distilled water, then transfer it to 50 mL of 1 mol / L sodium hydroxide solution, immerse it for 7 h, wash it until neutral, and immerse it in distilled water for 12 h. Dehydrate it at room temperature for 2 d, dry it at 63 °C to constant weight, and crush it to obtain modified sodium lignosulfonate powder;

[0089] (3) Add 2 g of alkali lignin to 45 ml of absolute ethanol, stir magnetically at room temperature for 2 h, then add 13 ml of 8 mol / L sodium hydroxide solution and 23 ml of 0.5 mol / L zinc nitrate hexahydrate solution. Then place the mixture in a water bath at 65 °C and heat it for 30 min. After the reaction, centrifuge it, wash it 3 times with deionized water and absolute ethanol respectively, dry it, place the obtained solid in a tubular furnace, calcine it at 550 °C for 3 h in a nitrogen atmosphere, cool it to room temperature, crush it, and sieve it to obtain modified lignin powder;

[0090] (4) Mix 2 g of modified lignin powder and 8 g of modified sodium lignosulfonate powder, disperse them evenly to obtain a modified ultraviolet absorber;

[0091] (5) Mix 100 g of polyethylene, 15 g of maleic anhydride grafted polyethylene, 7.5 g of modified ultraviolet absorber and 3 g of diisopropylbenzene peroxide, stir evenly to obtain a mixed material, and then carry out melt extrusion to obtain a sheath. Among them, the temperature of the extruder is: the first section is 150 °C, the second section is 155 °C, the third section is 160 °C, the fourth section is 160 °C, the fifth section is 160 °C, the sixth section is 160 °C, the seventh section is 160 °C, the eighth section is 160 °C, and the screw speed is 120 r / min. Insert four cables into the sheath to obtain an aging - resistant cable.

[0092] Comparative Example 6: An aging - resistant cable, and the specific preparation steps are as follows:

[0093] Mix 100 g of polyethylene, 15 g of maleic anhydride grafted polyethylene, 7.5 g of modified ultraviolet stabilizer, and 3 g of diisopropylbenzene peroxide, stir evenly to obtain a mixed material, and then perform melt extrusion to obtain a sheath. Among them, the temperatures of the extruder are: the first stage is 150 °C, the second stage is 155 °C, the third stage is 160 °C, the fourth stage is 160 °C, the fifth stage is 160 °C, the sixth stage is 160 °C, the seventh stage is 160 °C, the eighth stage is 160 °C, and the screw speed is 120 r / min. Insert four cables into the sheath to obtain an aging-resistant cable.

[0094] Performance Test

[0095] Mechanical Property Test:

[0096] Tensile property: Conducted in accordance with the ISO527 standard. Inject the obtained mixed material into a standard dumbbell-shaped specimen, and then use a universal material testing machine to perform tensile testing at a rate of 50 mm / min. The test results are shown in Table 1;

[0097] Flexural property: Conducted in accordance with the ISO178 standard. Inject the obtained mixed material into a specimen with a size of 80 mm × 10 mm × 4 mm. The support span of the support beam is 64 mm, 32 mm on each side of the indenter, and perform flexural property testing at a speed of 5 mm / min. The test results are shown in Table 1;

[0098] Volume resistivity: Tested by an electrometer. Cut the obtained sheath into 80 mm × 80 mm, and calculate the average value of multiple measurement data as the final result. The test results are shown in Table 1;

[0099] Aging test: Conducted according to GB / T 2951.12-2008 "General Test Methods for Insulating and Sheathing Materials of Cables and Optical Fibre Cables - Part 12: General Test Methods - Thermal Aging Test Methods". First, perform tensile strength testing on the obtained cable specimens, and then conduct the aging test. The main steps of the test are as follows: Hang the obtained cable specimens in the middle of the air thermal aging test chamber. The distance between each specimen and any other specimen should be at least 20 mm, and do not contact the inner wall of the aging chamber, except for the metal binding wire. Then turn on the heating of the aging chamber. Start timing when the temperature rises to 100 °C. After 240 h, take out the specimens for tensile strength testing. Among them, the aging retention rate = tensile strength after aging / tensile strength before aging × 100%. The test results are shown in Table 1.

[0100] Table 1 Performance Test Results

[0101]

[0102]

[0103] Data analysis: As can be seen from Examples 1 - 3 in Table 1, the anti - aging cable of the present invention has excellent mechanical strength, bending strength, and good insulation performance. Most importantly, it has excellent anti - aging performance and can meet the usage requirements in various harsh environments.

[0104] As can be seen from Examples 2 and Comparative Examples 1 - 6 in Table 1, the anti - aging cable prepared in Example 2 of the present invention is superior to the traditional polyethylene cable in Comparative Example 6 in terms of both mechanical properties, insulation properties, and anti - aging properties. This is mainly because zinc oxide, lignin, and sodium lignosulfonate itself have good anti - ultraviolet properties and insulation properties, and all three can act as physical reinforcement phases to improve the mechanical properties of the cable.

[0105] It can be illustrated by Example 2 and Comparative Example 3 that the effect of compounding lignin and sodium lignosulfonate is better than only using lignin to prepare the anti - ultraviolet agent. This is mainly because lignin and sodium lignosulfonate itself have good insulation and anti - aging properties. At the same time, due to the polar advantage of sodium lignosulfonate, lignin itself may exist inside the polyethylene cross - linked network, and the mutual attraction between the metal nanoparticles loaded by the two, the two have a certain synergy, can promote each other, jointly greatly improve the mechanical properties, insulation, and anti - aging properties of the anti - aging cable, and at the same time can make the compatibility between the modified anti - ultraviolet agent and polyethylene better, disperse more evenly, and avoid the problem that the formation of a conductive network between metal nanoparticles due to aggregation leads to a decrease in the insulation performance of the cable.

[0106] It can be illustrated by Example 2 and Comparative Examples 1 and 2 that the loaded Fe 3 O 4 can be evenly dispersed in the polyethylene matrix, and can improve the tensile strength and bending strength of the material through physical entanglement and interfacial stress transfer. At the same time, it has low conductivity and is wrapped by insulating sodium lignosulfonate, which can avoid the formation of a continuous conductive network, thus ensuring its insulation performance. And Fe 3 O 4 itself has a certain magnetic shielding effect, which can reduce the ultraviolet penetration depth, thus ensuring its anti - aging performance. Most importantly, its inherent magnetism can attract zinc oxide in the double - bond lignin, thereby improving the compatibility between the modified anti - ultraviolet agent and the polyethylene matrix, so that the mechanical properties, insulation properties, and anti - aging properties of the anti - aging cable are all improved to a certain extent. And using the hydrogel method to load Fe 3 O 4 can increase the loading amount of Fe 3 O 4 , and then optimize the performance of the anti - aging cable to a certain extent.

[0107] It can be illustrated by Example 2 and Comparative Examples 3 and 4 that by surface loading zinc oxide on lignin and further carrying out double bond treatment, the performance of the anti-aging cable is improved. This may be because during the melt extrusion process, the double-bonded lignin can exist in the cross-linked network of polyethylene. At the same time, the loaded zinc oxide can, on the one hand, improve the mechanical strength, insulation and anti-aging performance of the anti-aging cable, and on the other hand, can attract modified sodium lignosulfonate, so that the double-bonded lignin and the modified sodium sulfonate powder have a certain synergistic effect and can better exert the anti-aging performance of the modified UV absorber.

[0108] Those of ordinary skill in the art should understand that the discussion of any above embodiment is only exemplary and is not intended to imply that the scope of the present invention is limited to these examples; under the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present invention as described above, which are not provided in detail for the sake of brevity.

Claims

1. An aging-resistant cable, characterized in that: It comprises a sheath and a plurality of cables inserted into the sheath; The sheath is composed of the following raw materials in parts by weight: 90-110 parts of polyethylene, 10-20 parts of maleic anhydride grafted polyethylene, 5-10 parts of modified anti-ultraviolet agent and 1-5 parts of cross-linking agent; The modified anti-ultraviolet agent is a mixture of double-bonded lignin powder and modified sodium lignin sulfonate powder in a weight ratio of 1-3:5-10; The preparation steps of the double-bonded lignin powder are as follows: S11: adding alkali lignin to anhydrous ethanol, stirring magnetically at room temperature for 2 hours, then adding sodium hydroxide solution and zinc nitrate hexahydrate solution, and then heating the mixture in a water bath at 60-70°C for 30 minutes. After the reaction is completed, centrifuging, washing, and drying, placing the obtained solid in a tubular furnace, calcining at 500-600°C for 2-3 hours in a nitrogen atmosphere, cooling to room temperature, crushing, and sieving to obtain modified lignin powder; S12: dissolving the modified lignin powder in a sodium hydroxide solution, adding allyl glycidyl ether, reacting at room temperature for 24 h, precipitating, washing, and drying to obtain double-bonded lignin; The preparation steps of the modified sodium lignin sulfonate powder are as follows: S21: Sodium lignin sulfonate, acrylamide, N,N-methylenebis(acrylamide) and deionized water are mixed and dissolved by magnetic stirring to obtain a mixed solution; potassium persulfate is then dissolved in deionized water to obtain a potassium persulfate solution; the mixed solution and the potassium persulfate solution are mixed and shaken thoroughly, and then TEMED is added and reacted at 40-45° C. to obtain a sodium lignin sulfonate hydrogel; S22: Soak the sodium lignin sulfonate hydrogel in deionized water for 12 h, then soak the hydrogel in a mixed solution of ferrous sulfate heptahydrate and ferric chloride hexahydrate for 8-10 h, wash with distilled water after soaking, then transfer to a sodium hydroxide solution for 7-8 h, wash until neutral, soak in distilled water for 12 h, dehydrate at room temperature for 2-3 d, dry to constant weight, and crush to obtain modified sodium lignin sulfonate powder; In step S11, the usage ratio of alkali lignin, anhydrous ethanol, sodium hydroxide solution, and zinc nitrate hexahydrate solution is 1-3 g: 40-50 ml: 10-15 ml: 20-25 ml; The usage ratio of the modified lignin powder, the sodium hydroxide solution, and the allyl glycidyl ether in step S12 is 2-3 g: 50-70 mL: 10-15 mL; In step S21, the dosage ratio of sodium lignin sulfonate, acrylamide, N,N-methylenebis(acrylamide), deionized water, potassium persulfate and TEMED is 3-5 g:10-15 g:0.2-0.3 g:120-180 g:2-2.5 g:0.4-0.6 mL; The amount ratio of the sodium lignin sulfonate hydrogel, the mixed solution and the sodium hydroxide solution in step 22 is 5-10 g: 50-100 mL: 50 mL; The molar ratio of ferrous sulfate heptahydrate to ferric chloride hexahydrate in the mixed solution in step 22 is 1:1.

4.

2. The aging-resistant cable according to claim 1, characterized in that: The polyethylene is high-density polyethylene, and its melt index (190° C., 2.16 kg) is 0.8 g / 10 min.

3. The aging-resistant cable according to claim 1, characterized in that: The density of the maleic anhydride grafted polyethylene is 0.92 g / ml (25° C.).

4. The aging-resistant cable according to claim 1, characterized in that: The cross-linking agent is dicumyl peroxide.

5. The aging-resistant cable according to claim 1, characterized in that: The concentration of the sodium hydroxide solution in step S11 is 8 mol / L; the concentration of the zinc nitrate hexahydrate solution in step S11 is 0.5 mol / L.

6. The aging-resistant cable according to claim 1, characterized in that: The concentration of the sodium hydroxide solution in step S12 is 2 mol / L.

7. The aging-resistant cable according to claim 1, characterized in that: The concentration of the sodium hydroxide solution in step 22 is 1 mol / L.

8. A method for preparing an aging-resistant cable according to any one of claims 1 to 7, characterized in that: The specific preparation steps are as follows: Polyethylene, maleic anhydride grafted polyethylene, modified anti-ultraviolet agent and cross-linking agent are mixed and stirred evenly to obtain a mixture, which is then melt-extruded and formed to obtain a sheath. Four cables are inserted into the sheath to obtain an aging-resistant cable.

9. The method for preparing an aging-resistant cable according to claim 8, characterized in that: The extrusion temperatures of the extruder are 150°C for the first section, 155°C for the second section, 160°C for the third section, 160°C for the fourth section, 160°C for the fifth section, 160°C for the sixth section, 160°C for the seventh section, and 160°C for the eighth section, and the screw speed is 120r / min.

Images