A waterproof and corrosion-resistant cable sheath material and its preparation method

Abstract

This invention belongs to the technical field of cable sheath materials, specifically disclosing a waterproof and corrosion-resistant cable sheath material and its preparation method. The waterproof and corrosion-resistant cable sheath material comprises the following raw materials in parts by weight: 40-60 parts polyethylene, 15-20 parts acrylate rubber, 10-20 parts plasticizer, 10-15 parts compatibilizer, 3-5 parts lubricant, 1-5 parts antioxidant, 2-10 parts flame retardant, 5-10 parts modified carbon nanotubes, and 3-5 parts lignin derivatives. The addition of modified carbon nanotubes and lignin derivatives not only helps improve the mechanical properties of the cable sheath material but also endows it with excellent waterproof and corrosion-resistant capabilities.

Description

Technical Field

[0001] This invention belongs to the technical field of cable sheath materials, specifically relating to a waterproof and corrosion-resistant cable sheath material and its preparation method. Background Technology

[0002] Insulated cables play a vital role in modern society as an important medium for power transmission. The insulation sheath material, as a key component protecting the internal structure of the cable and ensuring safe and stable power transmission, directly affects the cable's service life and safety.

[0003] Currently, most insulated cable sheath materials are made of plastics such as polyethylene. While these materials possess certain insulation and mechanical strength, they still present numerous problems in practical applications. For instance, although polyethylene itself has some hydrophobicity, it is insufficient to completely prevent moisture penetration, especially in humid environments or under prolonged immersion conditions. Water molecules can gradually penetrate through defects in crystalline regions and the free volume of amorphous regions, leading not only to a decrease in insulation performance but also potentially causing "water treeing" and accelerating cable aging. Furthermore, when exposed to corrosive media such as acids, alkalis, or salt spray, the material surface may slowly deteriorate, potentially reducing the protective effect of the sheath over time. While these problems may not immediately cause failures in normal environments (non-extreme conditions), they can shorten the service life of the cable system. Therefore, further material modification is needed to improve the waterproof and corrosion-resistant properties of cable sheath materials. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the primary objective of this invention is to provide a waterproof and corrosion-resistant cable sheath material with excellent waterproof and corrosion-resistant capabilities.

[0005] Another objective of this invention is to provide a method for preparing the above-mentioned waterproof and corrosion-resistant cable sheath material, which has a simple process and provides a new approach for preparing waterproof and corrosion-resistant cable sheath materials.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A waterproof and corrosion-resistant cable sheath material comprises the following raw materials in parts by weight: 40-60 parts polyethylene, 15-20 parts acrylate rubber, 10-20 parts plasticizer, 10-15 parts compatibilizer, 3-5 parts lubricant, 1-5 parts antioxidant, 2-10 parts flame retardant, 5-10 parts modified carbon nanotubes, and 3-5 parts lignin derivatives.

[0008] The structure of the modified carbon nanotubes is as follows:

[0009] .

[0010] Furthermore, the preparation process of the modified carbon nanotubes is as follows:

[0011] (1) Disperse hydroxyl carbon nanotubes in N,N-dimethylformamide, then add 1,4-dichlorobenzyl and potassium carbonate, stir the reaction, filter, wash and dry after the reaction to obtain intermediate 1;

[0012] The structural formula of intermediate 1 is:

[0013]

[0014] (2) Intermediate 1 and [2-(5-imidazolyl)ethyl]acrylamide were added to acetonitrile and reacted under reflux conditions. After filtration and drying, the modified carbon nanotubes were obtained.

[0015] Further, in step (1), the ratio of hydroxyl carbon nanotubes, 1,4-dichlorobenzyl, potassium carbonate and N,N-dimethylformamide is 1 g: (2-4) g: (1.6-3.2) g: (60-90) mL; the stirring reaction time is 10-14 h.

[0016] Further, in step (2), the ratio of intermediate 1, [2-(5-imidazolyl)ethyl]acrylamide and acetonitrile is 1 g: (2-4) g: (150-200) mL; the reaction time is 12-15 h.

[0017] Furthermore, the preparation process of the lignin derivative is as follows:

[0018] (a) Add lignin and 1,6-hexanediamine to deionized water, adjust the pH to 10-10.5, add formaldehyde aqueous solution, react under heating conditions to obtain a reaction solution; cool the reaction solution to room temperature, add isopropanol to the reaction solution, filter, wash, and dry to obtain aminated lignin;

[0019] The structural formula of the aminated lignin is:

[0020]

[0021] (b) 1H,1H,2H,2H-perfluorooctanephosphonic acid and amination lignin were added to dimethyl sulfoxide and reacted under heating conditions; the reaction solution was cooled to room temperature, water was added to the reaction solution, filtered, washed, and dried to obtain the lignin derivative;

[0022] The structural formula of the lignin derivative is as follows:

[0023] .

[0024] Further, in step (a), the mass ratio of lignin, 1,6-hexanediamine, and formaldehyde aqueous solution is 1:(1.3-1.4):(1-1.1); the concentration of the formaldehyde aqueous solution is 37 wt%; the heating temperature is 50-60℃, and the reaction time is 5-8 h.

[0025] Further, in step (b), the ratio of aminated lignin, 1H,1H,2H,2H-perfluorooctanephosphonic acid and dimethyl sulfoxide is 1 g:(1-1.2) g:(50-75) mL; the heating temperature is 60-90℃, and the reaction time is 24-36 h.

[0026] Further, the polyethylene is composed of high-density polyethylene and low-density polyethylene in a mass ratio of 1:(1.5-3); the melt flow rate of the high-density polyethylene is (5-9) g / 10 min at 190°C and 2.16 kg, and the melt flow rate of the low-density polyethylene is (15-20) g / 10 min at 190°C and 2.16 kg; the lubricant is at least one of polyethylene wax, zinc stearate, and calcium stearate; the antioxidant is at least one of antioxidant 1010, antioxidant 1035, and antioxidant 168; the flame retardant is magnesium hydroxide; the plasticizer is dioctyl terephthalate; and the compatibilizer is at least one of POE-g-GMA, POE-g-MAH, and MAH-g-SBS.

[0027] The preparation method of the above-mentioned waterproof and corrosion-resistant cable sheath material includes the following steps: according to the stated weight proportions, polyethylene, acrylate rubber, plasticizer, compatibilizer, lubricant, antioxidant, flame retardant, modified carbon nanotubes and lignin derivatives are mixed evenly and then added to a twin-screw extruder, and after melt extrusion and granulation, the waterproof and corrosion-resistant cable sheath material is obtained.

[0028] Furthermore, the temperature range of each zone of the twin-screw extruder is 150-230℃, and the screw speed is 250-450 r / min.

[0029] The present invention has the following advantages over the prior art:

[0030] 1. The cable waterproof and corrosion-resistant sheath material provided by the present invention includes raw materials such as polyethylene, acrylic rubber, modified carbon nanotubes and lignin derivatives. The addition of modified carbon nanotubes and lignin derivatives not only helps to improve the mechanical properties of the cable sheath material, but also endows the cable sheath material with excellent waterproof and corrosion-resistant capabilities.

[0031] 2. This invention modifies the surface of carbon nanotubes using [2-(5-imidazolyl)ethyl]acrylamide, simultaneously introducing acrylate structures and functional imidazole groups onto the carbon nanotube surface. The introduced acrylate structure increases the affinity between the modified carbon nanotubes and the cable sheath material matrix, improving their compatibility and solving the problem of carbon nanotube agglomeration in traditional physical blending. Simultaneously, the grafted imidazole groups possess unique amphoteric properties, dynamically adjusting the pH value of the interfacial microenvironment through protonation or deprotonation reactions, effectively inhibiting the formation of corrosion microcells. This synergistic effect with the physical barrier effect of carbon nanotubes enhances the material's corrosion resistance. Furthermore, the imidazole groups exhibit excellent antibacterial properties, inactivating microorganisms and bacteria in the cable's operating environment. This reduces both the direct corrosive damage from microorganisms and the erosion of the material by acidic or alkaline liquids produced by their metabolism, thus achieving multiple protective effects.

[0032] 3. This invention modifies lignin by using 1,6-hexanediamine and 1H,1H,2H,2H-perfluorooctanephosphonic acid. On the one hand, the introduced perfluoroalkyl chain, combined with the intrinsic hydrophobic properties of lignin, can significantly reduce the surface energy of the material, forming a superhydrophobic surface that effectively hinders the wetting and penetration of water. On the other hand, the introduced amino and phosphonic acid groups can reduce the self-aggregation tendency of lignin derivatives, improve the dispersibility of lignin derivatives, and strengthen the interaction between lignin derivatives and the matrix, thereby constructing a denser waterproof barrier. Attached Figure Description

[0033] Figure 1 The FT-IR images of hydroxyl carbon nanotubes and modified carbon nanotubes in Example 1 are shown, where 1 is the result of hydroxyl nanotubes and 2 is the result of modified carbon nanotubes.

[0034] Figure 2 The FT-IR spectra of lignin and lignin derivatives in Example 4 are shown, where a represents the result for lignin and b represents the result for lignin derivatives. Detailed Implementation

[0035] The technical solution of the present invention will be further described below with reference to specific embodiments. However, those skilled in the art should understand that the following embodiments are only for illustrating the present invention and should not be regarded as limiting the present invention. Specific conditions not specified in the embodiments are performed according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the reagents or instruments used are all conventional products obtained through commercial channels.

[0036] The melt flow rate of the high-density polyethylene used in this invention is 5-9 g / 10 min at 190°C and 2.16 kg, and the melt flow rate of the low-density polyethylene is 15-20 g / 10 min at 190°C and 2.16 kg.

[0037] (a) Preparation example

[0038] Preparation Example 1

[0039] A modified carbon nanotube, the preparation process of which is as follows:

[0040]

[0041] (1) Hydroxycarbon nanotubes were dispersed in N,N-dimethylformamide according to the following ratio of hydroxycarbon nanotubes, 1,4-dichlorobenzyl chloride, potassium carbonate and N,N-dimethylformamide: 1 g: 3 g: 2.4 g: 75 mL. Then 1,4-dichlorobenzyl chloride and potassium carbonate were added. After stirring at room temperature for 12 h, the reaction was quenched by adding 6 mol / L hydrochloric acid solution. The mixture was filtered, and the solid product was washed with distilled water and saturated brine in sequence. After vacuum drying, intermediate 1 was obtained.

[0042] (2) According to the ratio of intermediate 1, [2-(5-imidazolyl)ethyl]acrylamide (CAS: 10124-85-3) and acetonitrile, 1 g: 3 g: 180 mL, intermediate 1 and [2-(5-imidazolyl)ethyl]acrylamide were added to acetonitrile and reacted under reflux for 14 h. Then, the mixture was cooled to room temperature, filtered, and vacuum dried to obtain modified carbon nanotubes.

[0043] The FT-IR images of the above-mentioned hydroxyl carbon nanotubes and modified carbon nanotubes are shown below. Figure 1 As shown, curve 1 corresponds to hydroxyl carbon nanotubes, and curve 2 corresponds to modified carbon nanotubes. From Figure 1 It can be seen that, compared to hydroxyl-containing carbon nanotubes, modified carbon nanotubes at 1725 cm⁻¹... -1 1485 cm -1 The presence of characteristic peaks for C=O and benzene rings indicates the successful synthesis of modified carbon nanotubes.

[0044] Preparation Example 2

[0045] A modified carbon nanotube, the reaction route is as shown in Preparation Example 1, and the specific preparation process is as follows:

[0046] (1) Hydroxycarbon nanotubes were dispersed in N,N-dimethylformamide according to the following ratio of hydroxycarbon nanotubes, 1,4-dichlorobenzyl chloride, potassium carbonate and N,N-dimethylformamide: 1 g: 2 g: 1.6 g: 60 mL. Then 1,4-dichlorobenzyl chloride and potassium carbonate were added. After stirring at room temperature for 10 h, the reaction was quenched by adding 6 mol / L hydrochloric acid solution. The mixture was filtered, and the solid product was washed with distilled water and saturated brine in sequence. After vacuum drying, intermediate 1 was obtained.

[0047] (2) According to the ratio of intermediate 1, [2-(5-imidazolyl)ethyl]acrylamide and acetonitrile, 1 g: 2 g: 150 mL, intermediate 1 and [2-(5-imidazolyl)ethyl]acrylamide were added to acetonitrile and reacted under reflux for 12 h. Then, the mixture was cooled to room temperature, filtered, and vacuum dried to obtain modified carbon nanotubes.

[0048] Preparation Example 3

[0049] A modified carbon nanotube, prepared via the reaction route shown in Preparation Example 1, is prepared as follows:

[0050] (1) Hydroxycarbon nanotubes, 1,4-dichlorobenzyl, potassium carbonate and N,N-dimethylformamide were dispersed in N,N-dimethylformamide according to the ratio of 1 g: 4 g: 3.2 g: 90 mL. Then 1,4-dichlorobenzyl and potassium carbonate were added. After stirring at room temperature for 14 h, the reaction was quenched by adding 6 mol / L hydrochloric acid solution. The mixture was filtered, and the solid product was washed with distilled water and saturated brine in sequence. After vacuum drying, intermediate 1 was obtained.

[0051] (2) According to the ratio of intermediate 1, [2-(5-imidazolyl)ethyl]acrylamide and acetonitrile, 1 g: 4 g: 200 mL, intermediate 1 and [2-(5-imidazolyl)ethyl]acrylamide were added to acetonitrile and reacted under reflux for 15 h. Then, the mixture was cooled to room temperature, filtered, and vacuum dried to obtain modified carbon nanotubes.

[0052] Preparation Example 4

[0053] A lignin derivative, the preparation process of which is as follows:

[0054]

[0055] (a) The raw materials were weighed according to the mass ratio of lignin, 1,6-hexanediamine and formaldehyde aqueous solution of 1:1.4:1. First, lignin and 1,6-hexanediamine were added to deionized water and mixed thoroughly to make the concentration of lignin in water 0.1 g / mL. Then, the pH value of the solution was maintained at 10 with 0.1 M NaOH and 0.1 M HCl solution. Then, 37 wt.% formaldehyde aqueous solution was added and reacted at 55 °C for 7 h. The reaction solution was cooled to room temperature and the product was precipitated by adding 5 times the volume of isopropanol. The product was filtered, washed with isopropanol, and dried in a vacuum oven at 50 °C to obtain aminated lignin.

[0056] (b) Following the ratio of aminated lignin, 1H,1H,2H,2H-perfluorooctanephosphonic acid and dimethyl sulfoxide of 1 g:1.1 g:60 mL, 1H,1H,2H,2H-perfluorooctanephosphonic acid (CAS: 252237-40-4) and aminated lignin were added to dimethyl sulfoxide and stirred until homogeneous. The reaction was carried out at 75 °C for 30 h. After the reaction solution was cooled to room temperature, an equal volume of deionized water was added to precipitate the product. The product was filtered, washed with deionized water, and dried in a vacuum oven to obtain the lignin derivative.

[0057] The FT-IR spectra of the above lignin and lignin derivatives are shown below. Figure 2 As shown, curve a corresponds to lignin, and curve b corresponds to lignin derivatives. Compared to lignin, lignin derivatives have a lower content of lignin at 1642 cm⁻¹. -1 1564 cm -1 1245cm -1 The presence of characteristic peaks for NH, NP, and P=O indicates the successful synthesis of the lignin derivative.

[0058] Preparation Example 5

[0059] A lignin derivative, prepared via the reaction route shown in Preparation Example 4, is prepared as follows:

[0060] (a) The raw materials were weighed according to the mass ratio of lignin, 1,6-hexanediamine and formaldehyde aqueous solution of 1:1.3:1.1. First, lignin and 1,6-hexanediamine were added to deionized water and mixed thoroughly to make the concentration of lignin in water 0.1 g / mL. Then, the pH value of the solution was maintained at 10.5 with 0.1 M NaOH and 0.1 M HCl solution. Then, 37 wt.% formaldehyde aqueous solution was added and reacted at 50 °C for 8 h. The reaction solution was cooled to room temperature and the product was precipitated by adding 5 times the volume of isopropanol. The product was filtered, washed with isopropanol, and dried in a vacuum oven at 50 °C to obtain aminated lignin.

[0061] (b) According to the ratio of aminated lignin, 1H,1H,2H,2H-perfluorooctanephosphonic acid and dimethyl sulfoxide 1 g:1 g:50 mL, 1H,1H,2H,2H-perfluorooctanephosphonic acid and aminated lignin were added to dimethyl sulfoxide and stirred evenly. The reaction was carried out at 60 °C for 36 h. After the reaction solution was cooled to room temperature, an equal volume of deionized water was added to precipitate the product. The product was filtered, washed with deionized water, and dried in a vacuum oven to obtain the lignin derivative.

[0062] Preparation Example 6

[0063] A lignin derivative, prepared via the reaction route shown in Preparation Example 4, is prepared as follows:

[0064] (a) The raw materials were weighed according to the mass ratio of lignin, 1,6-hexanediamine and formaldehyde aqueous solution of 1:1.4:1.1. First, lignin and 1,6-hexanediamine were added to deionized water and mixed thoroughly to make the concentration of lignin in water 0.1 g / mL. Then, the pH value of the solution was maintained at 10 with 0.1 M NaOH and 0.1 M HCl solution. Then, 37 wt.% formaldehyde aqueous solution was added and reacted at 60 °C for 5 h. The reaction solution was cooled to room temperature and the product was precipitated by adding 5 times the volume of isopropanol. The product was filtered, washed with isopropanol, and dried in a vacuum oven at 50 °C to obtain aminated lignin.

[0065] (b) Following the ratio of aminated lignin, 1H,1H,2H,2H-perfluorooctanephosphonic acid and dimethyl sulfoxide of 1 g:1.2 g:75 mL, 1H,1H,2H,2H-perfluorooctanephosphonic acid and aminated lignin were added to dimethyl sulfoxide and stirred until homogeneous. The mixture was reacted at 90 °C for 24 h. After the reaction solution was cooled to room temperature, an equal volume of deionized water was added to precipitate the product. The product was then filtered, washed with deionized water, and dried in a vacuum oven to obtain the lignin derivative.

[0066] (II) Implementation Examples

[0067] Example 1

[0068] A waterproof and corrosion-resistant cable sheath material comprises the following raw materials in parts by weight: 50 parts polyethylene, 18 parts acrylate rubber, 15 parts dioctyl terephthalate, 12 parts POE-g-GMA, 4 parts polyethylene wax, 3 parts antioxidant 1010, 6 parts magnesium hydroxide, 7 parts modified carbon nanotubes of Preparation Example 1, and 4 parts lignin derivatives of Preparation Example 4; wherein the polyethylene is composed of high-density polyethylene and low-density polyethylene in a mass ratio of 1:2.

[0069] Example 1 also provides a method for preparing the above-mentioned waterproof and corrosion-resistant cable sheath material, including the following steps:

[0070] According to the above-mentioned weight proportions, polyethylene, acrylate rubber, dioctyl terephthalate, POE-g-GMA, polyethylene wax, antioxidant 1010, magnesium hydroxide, modified carbon nanotubes, and lignin derivatives are mixed evenly and then added to a twin-screw extruder for melt extrusion and granulation to obtain a waterproof and corrosion-resistant cable sheath material. The temperature of the twin-screw extruder is 150℃ in zone 1, 210℃ in zones 2-5, and 230℃ in other zones, with a screw speed of 350 r / min.

[0071] Example 2

[0072] A waterproof and corrosion-resistant cable sheath material comprises the following raw materials in parts by weight: 40 parts polyethylene, 15 parts acrylate rubber, 10 parts dioctyl terephthalate, 10 parts POE-g-MAH, 3 parts zinc stearate, 1 part antioxidant 1035, 2 parts magnesium hydroxide, 5 parts modified carbon nanotubes of Preparation Example 2, and 3 parts lignin derivatives of Preparation Example 5; the polyethylene is composed of high-density polyethylene and low-density polyethylene in a mass ratio of 1:1.5.

[0073] Example 3 also provides a method for preparing the above-mentioned waterproof and corrosion-resistant cable sheath material, including the following steps:

[0074] According to the above-mentioned weight proportions, polyethylene, acrylate rubber, dioctyl terephthalate, POE-g-MAH, zinc stearate, antioxidant 1035, magnesium hydroxide, modified carbon nanotubes, and lignin derivatives are mixed evenly and then added to a twin-screw extruder for melt extrusion and granulation to obtain a waterproof and corrosion-resistant cable sheath material. The temperature of the twin-screw extruder is 150℃ in zone 1, 215℃ in zones 2-5, and 230℃ in other zones, with a screw speed of 250 r / min.

[0075] Example 3

[0076] A waterproof and corrosion-resistant cable sheath material comprises the following raw materials in parts by weight: 60 parts polyethylene, 20 parts acrylate rubber, 20 parts dioctyl terephthalate, 15 parts MAH-g-SBS, 5 parts calcium stearate, 5 parts antioxidant 168, 10 parts magnesium hydroxide, 10 parts modified carbon nanotubes of Preparation Example 3, and 5 parts lignin derivatives of Preparation Example 6; the polyethylene is composed of high-density polyethylene and low-density polyethylene in a mass ratio of 1:3.

[0077] Example 3 also provides a method for preparing the above-mentioned waterproof and corrosion-resistant cable sheath material, including the following steps:

[0078] According to the above-mentioned weight proportions, polyethylene, acrylate rubber, dioctyl terephthalate, MAH-g-SBS, calcium stearate, antioxidant 168, magnesium hydroxide, modified carbon nanotubes, and lignin derivatives are mixed evenly and then added to a twin-screw extruder for melt extrusion and granulation to obtain a waterproof and corrosion-resistant cable sheath material. The temperature of the twin-screw extruder is 150℃ in zone 1, 220℃ in zones 2-5, and 230℃ in other zones, with a screw speed of 450 r / min.

[0079] (III) Comparative Example

[0080] Comparative Example 1

[0081] Comparative Example 1 is basically the same as Example 1, except that the lignin derivative in Example 1 is replaced with lignin.

[0082] Comparative Example 2

[0083] Comparative Example 2 is basically the same as Example 1, except that the modified carbon nanotubes in Example 1 are replaced with carbon nanotubes.

[0084] (iv) Test Cases

[0085] Experimental Example 1

[0086] According to GB / T 2951.11-2008 General test methods for insulation and sheathing materials of cables and optical fibers - Part 11: General test methods for thickness and dimensional measurement and mechanical property testing, the mechanical properties of the cable sheathing materials prepared in Examples 1-3 and Comparative Examples 1-2 were tested, and the test results are shown in Table 1.

[0087] Table 1

[0088]

[0089] As shown in Table 1, the cable sheath materials prepared in Examples 1-3 of this invention exhibit excellent tensile strength and elongation at break. In Comparative Example 1, the lignin derivative in Example 1 was replaced with lignin; in Comparative Example 2, the modified carbon nanotubes in Example 1 were replaced with carbon nanotubes. Both showed a decrease in mechanical properties, indicating that the addition of lignin derivatives and modified carbon nanotubes can improve the mechanical properties of the cable sheath materials.

[0090] Experimental Example 2

[0091] The tensile strength and elongation at break of the cable sheath materials prepared in Examples 1-3 and Comparative Examples 1-2 were tested respectively, and used as the initial tensile strength and initial elongation at break. Then, each sample was subjected to the following tests: ① completely immersed in 50 wt% sulfuric acid aqueous solution for 30 days; ② completely immersed in 20 wt% sodium hydroxide aqueous solution for 30 days; ③ salt spray resistance test was conducted according to GB / T2423.17-2024 Environmental Testing Part 2: Test Methods Test Ka: Salt Spray, with a salt spray time of 168 hours. After each group of samples was taken out, the tensile strength and elongation at break were tested again. The change rate of tensile strength and elongation at break of each sample after acid, alkali and salt spray corrosion were calculated. The test results are shown in Table 2.

[0092] Table 2

[0093]

[0094] As shown in Table 2, the cable protection materials prepared in Examples 1-3 of this invention have excellent corrosion resistance.

[0095] Compared to Example 1, Comparative Example 1, which replaced the lignin derivative with lignin, showed little change in corrosion resistance; however, Comparative Example 2, which replaced the modified carbon nanotubes with carbon nanotubes, exhibited significantly worse corrosion resistance. This is likely because the present invention modifies the surface of carbon nanotubes using [2-(5-imidazolyl)ethyl]acrylamide, simultaneously introducing acrylate structures and functional imidazole groups onto the surface of the carbon nanotubes. The introduced acrylate structure increases the affinity between the modified carbon nanotubes and the cable sheath material matrix, improving their compatibility and solving the problem of easy agglomeration of carbon nanotubes in traditional physical blending. Simultaneously, the grafted imidazole groups possess unique amphoteric properties, dynamically adjusting the pH value of the interfacial microenvironment through protonation or deprotonation reactions, effectively inhibiting the formation of corrosion microcells, and synergistically enhancing the corrosion resistance of the material with the physical barrier effect of the carbon nanotubes. In addition, the imidazole group also exhibits good antibacterial properties, which can inactivate microorganisms and bacteria in the cable use environment. This reduces the direct corrosion and damage of materials by microorganisms and also reduces the erosion of materials by acidic and alkaline liquids produced by their metabolism, thus achieving multiple protective effects.

[0096] Experimental Example 3

[0097] The static surface water contact angle of the cable protection materials prepared in Examples 1-3 and Comparative Examples 1-2 was measured using the following methods:

[0098] First, each group of materials was soaked in deionized water for 48 hours. Then, the water on the surface of the materials was wiped off, and the materials were attached to a glass slide. Finally, 5 μL of water was dropped onto the surface of each group of materials using a micro-syringe. After the water droplets stabilized, the water droplets were photographed using a contact angle meter, and the contact angle values ​​of the water droplets in the images were measured and recorded. The static contact angle of each sample was measured at four different locations, and the average value was taken. The results are shown in Table 3.

[0099] Table 3

[0100]

[0101] As can be seen from Table 3, the cable protection materials prepared in Examples 1-3 and Comparative Example 2 of this invention have excellent superhydrophobicity, and the contact angle can reach 161°. o Compared to Example 1, the contact angle of Comparative Example 1 was significantly reduced, indicating that the addition of lignin derivatives endowed the cable sheath material with excellent waterproof capabilities. This invention modifies lignin using 1,6-hexanediamine and 1H,1H,2H,2H-perfluorooctanephosphonic acid. On one hand, the introduced perfluoroalkyl chains, combined with the intrinsic hydrophobic properties of lignin, significantly reduce the surface energy of the material, forming a superhydrophobic surface that effectively hinders water wetting and penetration. On the other hand, the introduced amino and phosphonic acid groups reduce the self-aggregation tendency of lignin derivatives, improve their dispersibility, and strengthen the interaction between the lignin derivatives and the matrix, thereby constructing a denser waterproof barrier.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. The basic principles and main features of the present invention have been described above with specific implementation schemes. Based on the present invention, some modifications or substitutions can be made, but these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of protection claimed by the present invention.

Claims

1. A waterproof and corrosion-resistant cable sheath material, characterized in that, The raw materials include the following parts by weight: 40-60 parts polyethylene, 15-20 parts acrylate rubber, 10-20 parts plasticizer, 10-15 parts compatibilizer, 3-5 parts lubricant, 1-5 parts antioxidant, 2-10 parts flame retardant, 5-10 parts modified carbon nanotubes, and 3-5 parts lignin derivatives. The structural formula of the modified carbon nanotubes is as follows: ； The structural formula of the lignin derivative is as follows: 。 2. The cable waterproof and corrosion-resistant sheath material according to claim 1, characterized in that, The preparation process of the modified carbon nanotubes is as follows: (1) Disperse hydroxyl carbon nanotubes in N,N-dimethylformamide, then add 1,4-dichlorobenzyl and potassium carbonate, stir the reaction, filter, wash and dry after the reaction to obtain intermediate 1; The structural formula of intermediate 1 is: (2) Intermediate 1 and [2-(5-imidazolyl)ethyl]acrylamide were added to acetonitrile and reacted under reflux conditions. After filtration and drying, the modified carbon nanotubes were obtained.

3. The cable waterproof and corrosion-resistant sheath material according to claim 2, characterized in that, In step (1), the ratio of hydroxyl carbon nanotubes, 1,4-dichlorobenzyl, potassium carbonate and N,N-dimethylformamide is 1 g: (2-4) g: (1.6-3.2) g: (60-90) mL; the stirring reaction time is 10-14 h.

4. The cable waterproof and corrosion-resistant sheath material according to claim 2, characterized in that, In step (2), the ratio of intermediate 1, [2-(5-imidazolyl)ethyl]acrylamide, and acetonitrile is 1 g: (2-4) g: (150-200) mL; the reaction time is 12-15 h.

5. The cable waterproof and corrosion-resistant sheath material according to claim 1, characterized in that, The preparation process of the lignin derivative is as follows: (a) Add lignin and 1,6-hexanediamine to deionized water, adjust the pH to 10-10.5, add formaldehyde solution, and react under heating conditions; cool the reaction solution to room temperature, add isopropanol to the reaction solution, filter, wash, and dry to obtain aminated lignin; The structural formula of the aminated lignin is: (b) 1H,1H,2H,2H-perfluorooctanephosphonic acid and amination lignin were added to dimethyl sulfoxide and reacted under heating conditions; the reaction solution was cooled to room temperature, water was added to the reaction solution, filtered, washed, and dried to obtain the lignin derivative; The structural formula of the lignin derivative is as follows: 。 6. The cable waterproof and corrosion-resistant sheath material according to claim 5, characterized in that, In step (a), the mass ratio of lignin, 1,6-hexanediamine, and formaldehyde aqueous solution is 1:(1.3-1.4):(1-1.1); the concentration of the formaldehyde aqueous solution is 37 wt%; the heating temperature is 50-60℃, and the reaction time is 5-8 h.

7. The cable waterproof and corrosion-resistant sheath material according to claim 5, characterized in that, In step (b), the ratio of aminated lignin, 1H,1H,2H,2H-perfluorooctanephosphonic acid and dimethyl sulfoxide is 1 g:(1-1.2) g:(50-75) mL; the heating temperature is 60-90℃ and the reaction time is 24-36 h.

8. The cable waterproof and corrosion-resistant sheath material according to claim 1, characterized in that, The polyethylene is composed of high-density polyethylene and low-density polyethylene in a mass ratio of 1:(1.5-3); the melt flow rate of the high-density polyethylene is (5-9) g / 10 min at 190°C and 2.16 kg, and the melt flow rate of the low-density polyethylene is (15-20) g / 10 min at 190°C and 2.16 kg; the lubricant is at least one of polyethylene wax, zinc stearate, and calcium stearate; the antioxidant is at least one of antioxidant 1010, antioxidant 1035, and antioxidant 168; the flame retardant is magnesium hydroxide; the plasticizer is dioctyl terephthalate; and the compatibilizer is at least one of POE-g-GMA, POE-g-MAH, and MAH-g-SBS.

9. A method for preparing the waterproof and corrosion-resistant cable sheath material according to any one of claims 1-8, characterized in that, Includes the following steps: According to the stated weight proportions, polyethylene, acrylate rubber, plasticizer, compatibilizer, lubricant, antioxidant, flame retardant, modified carbon nanotubes and lignin derivatives are mixed evenly and then added to a twin-screw extruder. After melt extrusion and granulation, the waterproof and corrosion-resistant cable sheath material is obtained.

10. The method for preparing the waterproof and corrosion-resistant cable sheath material according to claim 9, characterized in that, The temperature range of each zone of the twin-screw extruder is 150-230℃, and the screw speed is 250-450 r / min.

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