A self-healing ant-proof cable

Abstract

The present invention discloses a self-healing anti-termite cable, which includes an optical fiber sensor, a conductor, a conductor shielding layer, an insulating layer, an insulating shielding layer, a communication optical cable, a filling rope, an isolating sleeve, a steel tape armor and an outer sheath. The outer sheath comprises 50-70 parts of linear low density polyethylene, 40-60 parts of high density polyethylene, 0.9-1.2 parts of silane coupling agent, 0.12-0.15 parts of initiator, 1.8-3.0 parts of antioxidant, 1.2-1.5 parts of co-crosslinking agent, 1.2-1.5 parts of zinc oxide, 2.4-2.8 parts of catalyst, and 2-3 parts of anti-termite agent. When crosslinking polyethylene, a double network structure is formed by covalent bonds and supramolecular interactions. The covalent bonds ensure the basic mechanical properties of the material, and the supramolecular interactions provide a high self-healing efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of cables, and particularly relates to a self-repairing and termite-proof cable. Background Art

[0002] Most cables are laid underground in cities or directly buried in the soil. This laying method can reduce the impact on ground traffic and also protect the cables from external physical damage, but there will be problems of rats and termites gnawing. The research on cable termite prevention has a long history. Australia conducted experiments on drug termite prevention as early as the 1830s. In the initial stage of drug termite prevention, the termite prevention effect was obvious. However, when cable samples were retrieved several years later to measure the toxicity, it was found that the toxicity had decreased, which was mainly due to plastic aging and the gradual slow-release effect of the drug. To solve the problems of drug slow-release and environmental protection caused by the aging of the drug sheath plastic, scientists at home and abroad have also explored the research on cable termite prevention from the physical aspect. It mainly relies on hardness to prevent termites from gnawing, and the termite prevention effect is obvious. However, when the outer sheath of the cable is scratched during the construction process, it provides a breakthrough for termites to gnaw, thus affecting the termite prevention effect. Cross-linked polyethylene is mostly cross-linked through irreversible covalent bonds, resulting in the material not having self-repair ability. Although there is already a technology to repair cross-linked polyethylene by injecting a repair agent to react with water, there are differences in the molecular diffusion rates of the components of the repair liquid, and the initial position is prone to the accumulation and blockage of the repair liquid.

[0003] Intrinsic self-repair means that without adding a repair agent, the material can use dynamic bonds in the molecular network to achieve self-repair, and the self-repair can be repeated multiple times. Intrinsic self-repair at room temperature is mainly based on supramolecular interactions, including hydrogen bonds, ionic bonds, and metal-ligand interactions. However, most cables are directly buried in the soil, and the environment is humid. Polar supramolecular interactions are easily affected by the humid environment, and the hydrogen bond network is damaged, resulting in a decrease in the thermal and mechanical properties of the material. Summary of the Invention

[0004] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a self-repairing and termite-proof cable, which adopts a double network structure formed by covalent bonds and supramolecular interactions. The covalent bonds ensure the basic mechanical properties of the material, and the supramolecular interactions provide a high self-repair efficiency. The supramolecular interactions include hydrogen bonds between hydrophobic thiocarbonyl groups and ionic bonds between zinc and carboxyl groups.

[0005] The technical solution for achieving the purpose of the present invention is as follows:

[0006] A self-healing anti-termite cable, comprising an optical fiber sensor, a conductor, a conductor shielding layer, an insulating layer, an insulating shielding layer, a communication optical cable, a filling rope, an isolating sleeve, a steel tape armor and an outer sheath, characterized in that, by weight, the outer sheath comprises 50-70 parts of linear low-density polyethylene, 40-60 parts of high-density polyethylene, 0.9-1.2 parts of a silane coupling agent, 0.12-0.15 parts of an initiator, 1.8-3.0 parts of an antioxidant, 1.2-1.5 parts of a co-crosslinking agent, 1.2-1.5 parts of zinc oxide, 2.4-2.8 parts of a catalyst, and 2-3 parts of an anti-termite agent; the co-crosslinking agent has the molecular structure of formula I as follows:

[0007] , formula I; wherein n = 1-10, and R is at least one of aliphatic secondary amines or tertiary amines; the optical fiber sensor is directly implanted into the cable conductor, and can directly and accurately monitor various physical quantities during the operation of the cable.

[0008] Preferably, the co-crosslinking agent has at least one of the molecular structures of formula II or formula III as follows:

[0009] , formula II; , formula III.

[0010] More preferably, the co-crosslinking agent has the structure of formula II as above.

[0011] Preferably, the silane coupling agent is at least one of vinyltriethoxysilane and vinyltrimethoxysilane; the initiator is dicumyl peroxide; the catalyst is dibutyltin dilaurate; the anti-termite agent is at least one of n-nonanoic acid vanillylamide and FYJ-01 anti-termite functional masterbatch.

[0012] More preferably, the silane coupling agent is vinyltrimethoxysilane; the anti-termite agent is n-nonanoic acid vanillylamide and FYJ-01 anti-termite functional masterbatch with a mass ratio of (1-2):1.

[0013] Preferably, the physical quantities detected by the optical fiber sensor are temperature, partial discharge and stress.

[0014] Specifically, the molecular structure of formula I is obtained by the following steps:

[0015] S1. At room temperature, under nitrogen protection, add N,N'-thiocarbonyl diimidazole to a reaction kettle and add N,N-dimethylformamide to dissolve it. Dissolve diamino dialkylamine in N,N-dimethylformamide and slowly add it dropwise to the reaction kettle. After reacting for 1-2 h, add an aliphatic secondary amine or tertiary amine, raise the temperature to 40-60 °C, and continue to react for 4-6 h. Pour the mixture into cold water, precipitate a solid, filter, wash the filter cake with cold water, and dry to obtain a thiourea compound;

[0016] S2. Disperse the thiourea compound obtained in step S1 in N,N-dimethylformamide, add triethylamine and phthalic anhydride, stir at a temperature of 35-45 °C for 12-18 h, pour the reaction solution into cold ethyl acetate, filter out the precipitated solid, wash the filter cake with ethyl acetate, and dry it under vacuum to obtain the molecular structure of formula I.

[0017] Preferably, in step S1, the molar ratio of N,N'-thiocarbonyl diimidazole, dialkyldiamine to aliphatic secondary or tertiary amine is 2:1:(5-8); the dropping time of the dialkyldiamine is 30-60 min.

[0018] Preferably, in step S2, the molar ratio of the thiourea compound, triethylamine to phthalic anhydride is 1:(2-3):(1.5-2).

[0019] Preferably, a preparation method of a self-healing ant-proof cable comprises the following steps:

[0020] 1) Pre-preparation of the outer sheath material: Dissolve the initiator in the silane coupling agent, put linear low-density polyethylene and high-density polyethylene into an oven at 70-90 °C and dry for 10-12 h, then divide them into four equal parts. One part is mixed with the initiator and the silane coupling agent, one part is mixed with the catalyst, one part is mixed with the co-crosslinking agent and the ant-proof agent, and one part is mixed with zinc oxide. They are respectively placed in a sealed container and left standing for 18-24 h, and then extruded by a twin-screw extruder in turn to obtain a mixed masterbatch.

[0021] 2) Outer sheath material: Add the mixed masterbatch to a preheated single-screw extruder, extrude and wrap it on the steel tape armor, cool it by water bath, fix the obtained extruded material and place it in a humid environment at a temperature of 25-40 °C for 3-4 d. After completing the self-crosslinking process of polyethylene, dry it to obtain a self-healing ant-proof cable.

[0022] More preferably, the parameters of the twin-screw extruder in step 1) are a temperature of 75-165 °C and a main machine speed of 190-220 r / min; the parameters of the single-screw extruder in step 2) are a temperature of 170-210 °C and a main machine speed of 30-40 r / min.

[0023] Beneficial effects

[0024] The present invention has the following beneficial effects: It provides a self-healing anti-termite cable that can self-heal at room temperature when the cable is scratched; meanwhile, supramolecular interactions and irreversible covalent bonds are introduced. When subjected to external forces, the supramolecular interactions break first to dissipate energy, improving the mechanical properties of the material. At the same time, the covalent bonds ensure the integrity and elasticity of the material; using a silane coupling agent to crosslink polyethylene provides better mechanical properties for the outer sheath; after zinc oxide reacts with the co-crosslinking agent, the generated water can be used for the internal self-crosslinking of polyethylene, and at the same time, zinc forms an ionic bond with the carboxyl group to provide an ionic dynamic crosslinking network for the crosslinked polyethylene; the thiocarbonyl group, as a polar molecular structure, provides hydrogen bonds while having a certain hydrophobic ability, making it applicable to underground humid environments; the thiocarbonyl group can coordinate with zinc, further enhancing the strength of the dynamic non-covalent network. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of the overall self-healing anti-termite cable of the present invention;

[0026] In the figure: 100. Fiber optic sensor, 200. Conductor, 201. Conductor shielding layer, 202. Insulation layer, 203. Insulation shielding layer, 204. Filling cord, 205. Isolation sleeve, 206. Steel tape armor, 207. Outer sheath, 300. Communication optical cable;

[0027] Figure 2 It is a schematic diagram of the synthesis route and structure of the co-crosslinking agent of the present invention;

[0028] Figure 3 It is the crosslinking method of the self-healing anti-termite cable of the present invention;

[0029] Figure 4 It is the nuclear magnetic hydrogen spectrum of the co-crosslinking agent 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0031] In the embodiments, the experimental methods used are all conventional methods unless otherwise specified, and the materials, reagents, etc. used can be obtained from commercial channels unless otherwise specified.

[0032] Now, the raw materials and equipment used in the examples and comparative examples are described as follows:

[0033] Vinyltrimethoxysilane: Product number CH0020, Hubei Chenghai Chemical Co., Ltd.

[0034] Linear low-density polyethylene: brand DFDA-7042, purchased from Wuhan Rongchuang Plastic Co., Ltd.;

[0035] High-density polyethylene: item number 5000S, purchased from Dongguan Shenghua Plastic Raw Materials Co., Ltd.;

[0036] Ethylene-octene elastomer: brand 8999, purchased from Dongguan Yucheng Plastic Chemical Co., Ltd.;

[0037] Initiator: dicumyl peroxide, purchased from Nanjing Reagent;

[0038] Catalyst: dibutyltin dilaurate, purchased from Kangdisi Chemical (Hubei) Co., Ltd.;

[0039] Anti-ant agent 1: n-nonanoic acid vanillamide, HD-99, purchased from Qingdao Haida Chemical;

[0040] Anti-termite agent 2: FYJ-01 anti-termite functional masterbatch, purchased from Shenzhen Heyanyue Plastic Pigment;

[0041] N,N'-Thiocarbonyldiimidazole: Product No. S49067, purchased from Shanghai Yuanye Biotechnology Co., Ltd.;

[0042] Diethylenetriamine: purchased from Shandong Xinheng Chemical Co., Ltd.

[0043] Methylamine hydrochloride: purchased from Nanjing Reagent;

[0044] Methylamine tetrahydrofuran solution: prepared from methylamine hydrochloride;

[0045] Tetrahydrophthalic anhydride: purchased from Nanjing Oriental Pearl Industry and Trade Co., Ltd.;

[0046] Stearic acid: purchased from Nantong Runfeng Petrochemical Co., Ltd.

[0047] 3-Cyclohexenylcarbonyl chloride: Shanghai Baishun Biotechnology Co., Ltd.;

[0048] 3-Cyclohexene-1-carboxylic acid: product number 1033333, purchased from Shanghai Haohong Biomedicine Technology.

[0049] Cross-linking agent 1:

[0050] S1. At room temperature and under nitrogen protection, 2 mol of N,N'-thiocarbonyldiimidazole was added to a reaction kettle and N,N-dimethylformamide was added to dissolve it. 1 mol of diethylenetriamine was dissolved in N,N-dimethylformamide and slowly added dropwise to the reaction kettle. After reacting for 1 h, 8 mol of methylamine in tetrahydrofuran was added. The temperature was raised to 50°C and the reaction was continued for 6 h. The mixture was introduced into cold water to precipitate solids, which were filtered and the filter cake was washed with cold water and dried to obtain a thiourea compound.

[0051] S2. Disperse 1 mol of the thiourea compound obtained in step S1 in N,N-dimethylformamide, add 2 mol of triethylamine and 1.8 mol of phthalic anhydride, stir at 40 °C for 18 h, pour the reaction solution into cold ethyl acetate, filter out the precipitated solid, wash the filter cake with ethyl acetate, and dry it under vacuum to obtain the co-crosslinking agent 1.

[0052] Co-crosslinking agent 2:

[0053] S1. At room temperature and under nitrogen protection, add 2 mol of N,N'-thiocarbonyl diimidazole to the reaction kettle and dissolve it with N,N-dimethylformamide. Dissolve 1 mol of diethylenetriamine in N,N-dimethylformamide and slowly add it dropwise to the reaction kettle. After reacting for 1 h, add a tetrahydrofuran solution of 8 mol of methylamine, raise the temperature to 50 °C, and continue to react for 6 h. Pour the mixture into cold water, filter out the precipitated solid, wash the filter cake with cold water, and dry it to obtain the thiourea compound.

[0054] S2. Disperse 1 mol of the thiourea compound obtained in step S1 in N,N-dimethylformamide, add 2 mol of triethylamine and 1.8 mol of 3-cyclohexenylcarbonyl chloride, stir at 40 °C for 18 h, pour the reaction solution into cold ethyl acetate, filter out the precipitated solid, wash the filter cake with ethyl acetate, and dry it under vacuum to obtain the co-crosslinking agent 2.

[0055] A preparation method of a self-healing ant-proof cable includes the following steps:

[0056] 1) Pre-preparation of the outer sheath material: Dissolve the initiator in the silane coupling agent. Put linear low-density polyethylene and high-density polyethylene into an 80 °C oven and dry for 12 h, then divide them into four equal parts. Mix one part with the initiator and the silane coupling agent, one part with the catalyst, one part with the co-crosslinking agent and the ant-proof agent, and one part with zinc oxide. Put them into airtight containers and let them stand for 24 h. Then, use a twin-screw extruder at a temperature of 75 - 165 °C and a main machine speed of 190 - 220 r / min to extrude and mix to obtain the masterbatch.

[0057] 2) Outer sheath material: Add the masterbatch to a preheated single-screw extruder, at a temperature of 170 - 210 °C and a main machine speed of 30 - 40 r / min, extrude and coat it on the steel tape armor. After water bath cooling, fix the obtained extruded material and place it in a humid environment at 25 - 40 °C for 3 - 4 d. After completing the self-crosslinking process of polyethylene, dry it to obtain the self-healing ant-proof cable.

[0058] Table 1 Formulation of examples and comparative examples (kg)

[0059]

[0060] Among them, the cross-linked polyethylene in Comparative Example 3 was not modified with carboxyl groups, and the cross-linked polyethylene in Comparative Example 4 was not modified with thiocarbonyl groups.

[0061] The following are the test methods for the performance parameters involved in the present invention:

[0062] 1. Ant-proof performance: Test the products of the examples and comparative examples according to the standard GB / T2951.38-1986, and record the corrosion grade;

[0063] 2. Surface hardness test: Test the Shore hardness of the products of the examples and comparative examples according to the standard ISO 7619-1:2012-02;

[0064] 3. Abrasion resistance test: Test the abrasion of the products of the examples and comparative examples according to the standard GB / T 5478-2008; among them, the single-arm load is 1000 g, and the double-pass impact is 20000 times, and record the wear amount;

[0065] 4. Self-healing performance test: Place the outer protective layer, blade and wood chip from bottom to top, load a 30 kg heavy object above the wood chip, and push the wood chip from front to back, thereby forming a scratch on the surface of the outer protective layer, and repair it with a 1 kg pressure. Use a stereomicroscope to photograph and measure the scratch width before repair d1 / after repair d2:

[0066] Repair efficiency = .

[0067] Table 2 Performance tests of examples and comparative examples

[0068]

[0069] From the data of Examples 2 to 6, it can be seen that as the mass ratio of the silane coupling agent to the co-crosslinking agent decreases, the hardness of the obtained outer sheath becomes lower and the repair efficiency gradually increases. The silane coupling agent provides irreversible covalent bonds to increase the hardness, and the supramolecular interaction improves the self-healing efficiency of the outer sheath; from the data of Comparative Examples 1 to 2, it can be seen that too large or too small mass ratio of the alkane coupling agent to the co-crosslinking agent will affect the performance of the outer sheath; from the data of Comparative Examples 3 to 4, it can be seen that the performance of a single type of supramolecular interaction on the hardness and self-healing efficiency of the outer sheath is not as excellent as that of multiple supramolecular interactions.

[0070] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A self-repairing anti-ant cable, comprising an optical fiber sensor, a conductor, a conductor shielding layer, an insulating layer, an insulating shielding layer, a communication optical cable, a filling rope, an isolation sleeve, a steel belt armor and an outer sheath, characterized in that: The outer sheath comprises, by weight, 50-70 parts of linear low-density polyethylene, 40-60 parts of high-density polyethylene, 0.9-1.2 parts of silane coupling agent, 0.12-0.15 parts of initiator, 1.8-3.0 parts of antioxidant, 1.2-1.5 parts of auxiliary cross-linking agent, 1.2-1.5 parts of zinc oxide, 2.4-2.8 parts of catalyst, and 2-3 parts of anti-termite agent; the auxiliary cross-linking agent has the following molecular structure of Formula I: , formula I; wherein n=1~10, R is at least one of aliphatic secondary amine or tertiary amine; the optical fiber sensor is directly implanted into the cable conductor, and can directly and accurately monitor various physical quantities of the cable operation.

2. A self-repairing anti-ant cable as claimed in claim 1, characterized in that: The auxiliary cross-linking agent has at least one of the following molecular structures: , Formula II; , Formula III.

3. A self-repairing anti-ant cable as claimed in claim 1, characterized in that: The silane coupling agent is at least one of vinyl triethoxysilane and vinyl trimethoxysilane; the initiator is dicumyl peroxide; the catalyst is dibutyltin dilaurate; and the termite repellent is at least one of n-nonanoic acid vanillamide and FYJ-01 anti-termite functional masterbatch.

4. The self-repairing anti-ant cable according to claim 1, characterized in that: The physical quantities detected by the optical fiber sensor are temperature, partial discharge and stress.

5. The self-repairing anti-ant cable according to claim 1, characterized in that: The molecular structure of formula I is obtained by the following steps: S1. At room temperature and under nitrogen protection, N,N'-thiocarbonyldiimidazole is added to a reaction kettle and N,N-dimethylformamide is added to dissolve it. Diaminodialkylamine is dissolved in N,N-dimethylformamide and slowly added dropwise to the reaction kettle. After reacting for 1-2 hours, an aliphatic secondary amine or tertiary amine is added. The temperature is raised to 40-60 °C and the reaction is continued for 4-6 hours. The mixture is introduced into cold water to precipitate a solid, which is filtered and the filter cake is washed with cold water and dried to obtain a thiourea compound. S2. The thiourea compound obtained in step S1 is dispersed in N,N-dimethylformamide, triethylamine and tetrahydrophthalic anhydride are added, and the mixture is stirred at a temperature of 35-45°C for 12-18 hours. The reaction solution is poured into cold ethyl acetate, the precipitated solid is filtered, the filter cake is washed with ethyl acetate, and vacuum dried to obtain a molecular structure of formula I.

6. A self-repairing anti-ant cable as claimed in claim 5, characterized in that: In step S1, the molar ratio of N,N'-thiocarbonyldiimidazole, diaminodialkylamine and aliphatic secondary or tertiary amine is 2:1:(5-8); the dropping time of the diaminodialkylamine is 30-60 min.

7. The self-repairing anti-ant cable according to claim 5, characterized in that: The molar ratio of the thiourea compound, triethylamine and tetrahydrophthalic anhydride in step S2 is 1:(2-3):(1.5-2).

8. The method for preparing a self-repairing anti-ant cable according to claim 1, characterized in that: The following steps are involved: 1) Pre-preparation of outer sheath material: dissolve the initiator in the silane coupling agent, put the linear low-density polyethylene and high-density polyethylene into a 70-90 ℃ oven and dry them for 10-12 hours, then divide them into four equal parts, one part is mixed with the initiator and the silane coupling agent, one part is mixed with the catalyst, one part is mixed with the auxiliary cross-linking agent and the anti-termite agent, and one part is mixed with zinc oxide, and they are placed in sealed containers and left to stand for 18-24 hours, and then extruded by a twin-screw extruder in turn to obtain mixed masterbatch; 2) Outer sheath material: The mixed masterbatch is added into a preheated single screw extruder and extruded onto the steel belt armor. After cooling in a water bath, the extruded material is fixed and placed in a humid environment at a temperature of 25-40 ℃ for 3-4 days. After the self-crosslinking process of the polyethylene is completed, it is dried to obtain a self-repairing anti-ant cable.

9. A method for preparing a self-repairing anti-ant cable according to claim 8, characterized in that: The parameters of the twin-screw extruder in step 1) are a temperature of 75-165°C and a main engine speed of 190-220 r / min; the parameters of the single-screw extruder in step 2) are a temperature of 170-210°C and a main engine speed of 30-40 r / min.

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