Optical cable sheath material and preparation method thereof

Abstract

The invention relates to the field of optical cable manufacturing, and particularly discloses an optical cable sheath material and a preparation method thereof. The optical cable sheath material comprises the following components: polyvinylidene fluoride, natural rubber, nano montmorillonite, flexible zirconia fibers, an anti-ultraviolet agent and epoxidized soybean oil. The preparation method comprises the following steps: plastifying and softening the natural rubber, controlling the temperature to be 50-60 DEG C, and keeping the plastifying and softening for 5-10 minutes; the preparation method comprises the following steps: melting and mixing polyvinylidene fluoride at 160-180 DEG C for 5-10 minutes; the preparation method comprises the following steps: sequentially adding nano montmorillonite, flexible zirconium oxide fibers, natural rubber, epoxidized soybean oil and an anti-ultraviolet agent into molten polyvinylidene fluoride, and continuously mixing for 20-30 minutes; and carrying out extrusion molding on the uniformly mixed material at the temperature of 160-200 DEG C to obtain the required optical cable sheath. The optical cable sheath material has the advantages that an optical cable sheath has better weather resistance in a complex environment, and the service life is prolonged.

Description

Technical Field

[0001] This application relates to the field of optical cable manufacturing, and more specifically, to an optical cable sheath material and a preparation method thereof. Background Art

[0002] With the rapid development of information technology, the global demand for data transmission rate and capacity has increased significantly. As the main carrier of information transmission, optical cables play an increasingly important role. Optical cables, with their advantages of high bandwidth, low loss, anti-interference, etc., have become the core of modern communication networks. However, the performance and quality of optical cables directly affect the stability and reliability of communication systems. In particular, the optical cable sheath material plays a crucial role in protecting and supporting the entire optical cable structure.

[0003] The optical cable sheath is the outermost part of the optical cable, mainly used to prevent the influence of external environmental factors (such as mechanical stress, moisture, chemical corrosion, etc.) on the optical cable. Currently, common optical cable sheath materials are mainly plastics and rubbers, such as polyethylene, polyvinyl chloride, fluoroplastics, ethylene-propylene rubber, etc. These materials have good insulation, wear resistance, and anti-ultraviolet ability, and are easy to process and form.

[0004] However, in actual use, although plastic materials have excellent mechanical properties and moisture-proof properties, the aging of the optical cable sheath is an inevitable problem during the use of optical cables. When exposed to ultraviolet rays or extreme climate conditions for a long time, it is easy to age, resulting in a decrease in its strength and toughness, and phenomena such as cracking and embrittlement; while rubber materials will gradually lose their elasticity in high-temperature and humid environments, which will then lead to cracking or deformation of the optical cable sheath and cannot effectively protect the optical cable. Summary of the Invention

[0005] In order to enable the optical cable sheath to have better weather resistance in complex environments and extend its service life, this application provides an optical cable sheath material and a preparation method thereof.

[0006] An optical cable sheath material provided by this application adopts the following technical solution: An optical cable sheath material, comprising the following components by weight: 60 - 70 parts of polyvinylidene fluoride, 10 - 15 parts of natural rubber, 3 - 5 parts of nano-montmorillonite, 5 - 10 parts of flexible zirconia fiber, 1 - 3 parts of anti-ultraviolet agent, 5 - 10 parts of epoxidized soybean oil.

[0007] By adopting the above technical solutions, ultraviolet rays are one of the main factors leading to material aging, and anti-ultraviolet agents can slow down the degradation rate of polymer chains, prevent embrittlement and cracking caused by long-term exposure to sunlight, and significantly extend the service life of the optical cable sheath. As the matrix material, polyvinylidene fluoride (PVDF) itself has excellent chemical corrosion resistance, high temperature resistance and anti-ultraviolet performance, and can remain stable under extreme climate conditions. This property enables it to maintain the physical properties of the optical cable sheath in harsh environments such as high temperature and humidity. Nano-montmorillonite has good barrier properties, which can further improve the moisture-proof performance of the material, prevent moisture penetration, and slow down the aging rate of the material in a humid environment. The combination of PVDF and nano-montmorillonite not only enhances the thermal stability of the material but also improves its processing performance. At a relatively high temperature, the melt viscosity of PVDF is low, making it easy to extrude and form, while the addition of nano-montmorillonite effectively inhibits the excessive fluidity of polymer chains, improving the dimensional stability and heat resistance of the material. The introduction of natural rubber and epoxidized soybean oil endows the material with good flexibility. In low-temperature or high-temperature environments, natural rubber maintains good elasticity, while epoxidized soybean oil, as a plasticizer, increases the softness of the material and reduces the risk of cracking of the sheath. At the same time, epoxidized soybean oil can also provide a certain degree of antioxidant ability, further enhancing the anti-aging performance of the material. Flexible zirconia fibers can improve the mechanical strength and impact resistance of the material. Zirconia fibers have good thermal stability and high temperature resistance, and can maintain strength under complex climate conditions, thus delaying the performance degradation of the material. Through the optical cable sheath material of the present invention, the synergistic effect of each component greatly improves the weather resistance, anti-aging performance, mechanical strength and flexibility of the material. This material can maintain excellent performance under extreme climate conditions and extend the service life of the optical cable sheath.

[0008] Optionally, it further includes 4-8 parts of self-healing polymer.

[0009] Optionally, the preparation method of the self-healing polymer is as follows: Mix polyethylene glycol and dimethyl dithiodibenzoate, add an initiator at 120-130 °C for polymerization reaction to form a polymer with disulfide bonds, add a disulfide cross-linking agent, and carry out a cross-linking reaction at 70-80 °C, and keep the temperature for 2-4 h.

[0010] By adopting the above technical solution, the self-healing polymer realizes the self-healing property by introducing disulfide bonds (S-S bonds) into the polymer backbone. When microcracks or damages occur in the optical cable sheath material under external force, the existence of disulfide bonds enables the material to heal spontaneously. Compared with other self-healing materials, the present application can self-repair at a lower temperature, slow down the decline of material properties, and extend the service life of the optical cable. The preparation process is simple and easy to operate, and the material exhibits a high self-healing efficiency at room temperature without the need for special external repair media or complex conditions. The self-healing polymer combines with components such as polyvinylidene fluoride and natural rubber in the material, further enhancing the overall flexibility and impact resistance of the material.

[0011] Optionally, the flexible zirconia fiber has a diameter of 2 - 4 μm and a length of 1 - 3 mm.

[0012] By adopting the above technical solution, the fibers with micron-level diameter endow the material with good flexibility and appropriate mechanical strength, enabling the material to maintain a certain strength while still possessing certain bending and deformation capabilities. The fiber size of 1 - 3 mm can provide the necessary strengthening effect for the material while maintaining the softness of the flexible material, preventing the material from being too fragile. The distribution of the flexible zirconia fibers of this specification in the material can effectively disperse stress, thereby improving the fatigue resistance of the material. In the case of repeated bending and stretching, the fiber structure can delay the generation of cracks and extend the service life of the material.

[0013] Optionally, the preparation method of the flexible zirconia fiber is as follows: Add nano-aluminum oxide and polyethylene glycol to a zirconium oxychloride solution with a mass concentration of 40 - 60%. The dosage of nano-aluminum oxide is 2 - 6% of the mass of the zirconium oxychloride solution, and the dosage of polyethylene glycol is 4 - 8% of the mass of the zirconium oxychloride solution. After mixing evenly, a precursor solution is obtained. The precursor solution of the zirconium oxychloride solution is drawn into fibers through solution spinning technology, and then the fibers are subjected to gelation treatment in ammonia water with a mass concentration of 5 - 10%. Dry the fibers after gelation treatment at a temperature of 60 - 100 °C, and pre-sinter the dried fibers at a temperature of 300 - 500 °C for 1 - 2 h. Sinter the pre-sintered fibers at 1200 - 1600 °C for 1 - 3 h. After sintering is completed, cool the fibers to room temperature to obtain flexible zirconia fibers.

[0014] By adopting the above technical solutions, nano-aluminum oxide effectively inhibits the growth of zirconia grains during the sintering process, preventing the increase in brittleness caused by excessive grain growth of fibers at high temperatures. Polyethylene glycol can endow the fibers with higher flexibility during the forming stage, making the fibers easier to stretch and form. During the sintering process, PEG will gradually burn off. Through the special ratio of nano-aluminum oxide and polyethylene glycol, the balance between the mechanical properties and flexibility of the fibers is ensured. By carrying out gelation treatment in 5-10% ammonia water, chemical cross-linking reactions can occur in the zirconia precursor fibers, further stabilizing the initial morphology of the fibers and helping to improve the shape stability of the fibers during subsequent sintering. The flexible zirconia fibers prepared by this method have high strength while maintaining good flexibility.

[0015] Optionally, the ultraviolet absorber includes Tinuvin 770 and nano-titanium dioxide, and Tinuvin 770 and nano-titanium dioxide are compounded according to a mass ratio of (7-9):2.

[0016] By adopting the above technical solutions, Tinuvin 770 captures free radicals, inhibits the aging of materials caused by ultraviolet radiation, prevents the breakage and degradation of polymer chains, and can play a role stably for a long time. Especially in an environment of long-term ultraviolet exposure, it can effectively delay the powdering and cracking of materials and ensure the appearance and mechanical properties of materials. Nano-titanium dioxide can effectively absorb and scatter the UVA and UVB spectra in ultraviolet rays, forming a physical shielding layer to prevent ultraviolet rays from directly penetrating the materials. The compounding of Tinuvin 770 and nano-titanium dioxide makes full use of the synergistic effect of organic and inorganic ultraviolet absorbers, which can not only prevent the generation of free radicals induced by ultraviolet rays from the inside, but also provide physical barriers from the outside. The dual protection effectively improves the ultraviolet resistance of the materials. Compounding according to a mass ratio of (7-9):2 ensures a reasonable balance of the two components.

[0017] In a second aspect, the present application provides a preparation method for an optical cable sheath material, adopting the following technical solutions: A preparation method for an optical cable sheath material, comprising the following steps: Plasticize and soften natural rubber, control the temperature at 50-60°C, and continue for 5-10 min; Melt and knead polyvinylidene fluoride at 160-180°C for 5-10 min; In the molten polyvinylidene fluoride, sequentially add nano-montmorillonite, flexible zirconia fibers, natural rubber, epoxidized soybean oil, and an ultraviolet absorber, and continue kneading for 20-30 min; Extrude and mold the uniformly kneaded material at a temperature of 160-200°C to obtain the required optical cable sheath.

[0018] Optionally, a self-healing polymer is also added to the molten polyvinylidene fluoride.

[0019] By adopting the above technical solution, after the natural rubber is plasticized and softened, the material is endowed with excellent flexibility and fatigue resistance, and the service life of the optical cable is extended. Polyvinylidene fluoride (PVDF) is fully integrated with other components during the melt mixing process, providing excellent corrosion resistance, weather resistance and mechanical strength. The flexible zirconia fiber enhances the high-temperature resistance of the material and maintains its flexibility in a high-temperature environment. Epoxidized soybean oil as a plasticizer further improves the flexibility and processing performance of the material, while the ultraviolet absorber effectively prevents the material from aging caused by ultraviolet rays. The optional self-healing polymer provides the optical cable sheath material with the ability of self-repair and extends its service life.

[0020] In summary, the present application has the following beneficial effects: 1. Since the present application uses polyvinylidene fluoride as the matrix material, it has excellent chemical corrosion resistance, high temperature resistance and ultraviolet resistance, and can maintain stability under extreme climate conditions. The addition of nano-montmorillonite further enhances the moisture resistance and thermal stability of the material, effectively inhibiting moisture penetration and excessive flow of polymer chains. The introduction of natural rubber and epoxidized soybean oil endows the material with good flexibility and anti-aging performance, ensuring that it can still maintain elasticity and prevent cracking in low-temperature and high-temperature environments. The flexible zirconia fiber improves the mechanical strength and impact resistance of the material and enhances its high-temperature resistance. The ultraviolet absorber effectively slows down the degradation of polymer chains caused by ultraviolet rays and extends the service life of the optical cable sheath. The synergistic effect of each component enables the optical cable sheath material to maintain excellent performance in harsh environments and significantly extends the service life.

[0021] 2. In the present application, a self-healing polymer is preferably used. By introducing disulfide bonds into the polymer main chain, the material is endowed with self-healing characteristics. When microcracks or damages appear in the optical cable sheath under external force, the disulfide bonds can promote the spontaneous healing of the material, and the repair can be achieved at a relatively low temperature. Compared with other self-healing materials, this solution has high repair efficiency, simple preparation process, and does not require special external media or complex conditions.

[0022] 3. In the present application, flexible zirconia fibers with a diameter of 2-4 μm and a length of 1-3 mm are preferably used, endowing the material with good flexibility and appropriate mechanical strength, ensuring that the material has bending and deformation capabilities while maintaining a certain strength. During its preparation process, nano-aluminum oxide and polyethylene glycol are added to the zirconium oxychloride solution, and then solution spinning technology is used to make fibers, which are subjected to ammonia gelation and high-temperature sintering. Nano-aluminum oxide inhibits the growth of crystal grains, and polyethylene glycol endows the fibers with higher flexibility. The finally prepared fibers have excellent flexibility while maintaining high strength. Detailed implementation mode

[0023] The following further elaborates on this application in conjunction with embodiments. It should be specifically noted that: for those not specifying specific conditions in the following embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following embodiments can all be obtained from ordinary commercial sources.

[0024] Preparation Examples of Self - healing Polymers Preparation Example 1 Preparation Method of Self - healing Polymer: Add 70 kg of polyethylene glycol (molecular weight in the range of 4000 - 6000 Da) and 30 kg of dimethyl dithiodibenzoate into a reaction kettle, mix under stirring conditions to ensure uniform dispersion of the two.

[0025] Under a nitrogen environment, heat the mixture to 125 °C, add 1 kg of azobisisobutyronitrile as an initiator, keep the temperature for 2 h, and carry out a polymerization reaction.

[0026] After the polymerization reaction is completed, add 3.5 kg of hexamethylenedithiocarbamic acid as a cross - linker to the reaction system, adjust the reaction temperature to 75 °C, and maintain this temperature for 3 hours. After completion, naturally cool the polymer to room temperature to obtain the self - healing polymer.

[0027] Preparation Example 2 Preparation Method of Self - healing Polymer: Add 60 kg of polyethylene glycol (molecular weight in the range of 4000 - 6000 Da) and 40 kg of dimethyl dithiodibenzoate into a reaction kettle, mix under stirring conditions to ensure uniform dispersion of the two.

[0028] Under a nitrogen environment, heat the mixture to 125 °C, add 1 kg of azobisisobutyronitrile as an initiator, keep the temperature for 2 h, and carry out a polymerization reaction.

[0029] After the polymerization reaction is completed, add 3.5 kg of hexamethylenedithiocarbamic acid as a cross - linker to the reaction system, adjust the reaction temperature to 75 °C, and maintain this temperature for 3 hours. After completion, naturally cool the polymer to room temperature to obtain the self - healing polymer.

[0030] Preparation Example 3 Preparation Method of Self - healing Polymer: Add 80 kg of polyethylene glycol (molecular weight in the range of 4000 - 6000 Da) and 20 kg of dimethyl dithiodibenzoate into a reaction kettle, mix under stirring conditions to ensure uniform dispersion of the two.

[0031] Under a nitrogen environment, heat the mixture to 125 °C, add 1 kg of azobisisobutyronitrile as an initiator, keep the temperature for 2 h, and carry out a polymerization reaction.

[0032] After the polymerization reaction is completed, 3.5 kg of hexamethylenedithiocarbamic acid is added to the reaction system as a crosslinking agent, the reaction temperature is adjusted to 75 °C, and this temperature is maintained for 3 hours. After completion, the polymer is naturally cooled to room temperature to obtain a self-healing polymer.

[0033] Preparation Example of Flexible Zirconia Fiber Preparation Example 4 Preparation method of flexible zirconia fiber: Add 20 kg of zirconium oxychloride solution with a mass concentration of 50% to a stirring tank, slowly add 0.8 kg of nano-aluminum oxide to the zirconium oxychloride solution, and then add 0.12 kg of polyethylene glycol. Continue to stir the mixture in the stirring tank to ensure the uniform dispersion of nano-aluminum oxide and polyethylene glycol, forming a stable precursor solution.

[0034] Inject the precursor solution into the nozzle of the solution spinning device, and extrude the solution under pressure to form a fibrous liquid. Immerse the drawn fiber in ammonia water with a mass concentration of 8% for gelation treatment. Keep the fiber immersed in ammonia water for 30 min.

[0035] Take out the fiber after gelation treatment and drain it to remove the excess ammonia water solution on the surface. Place the fiber in a drying oven at 80 °C for drying treatment until the fiber is completely dry.

[0036] Put the dried fiber into a sintering furnace, the heating rate should be controlled at 3 - 5 °C / min, and the temperature is controlled at 400 °C for pre-sintering, and the time is 1.5 hours.

[0037] After the pre-sintering is completed, continue to sinter the fiber in the sintering furnace at a high temperature of 1400 °C, and the time is controlled at 2 hours.

[0038] After the sintering is completed, slowly cool the fiber in the furnace to room temperature to obtain flexible zirconia fiber. The cooling rate is controlled at 5 - 10 °C / min to prevent cracks or structural damage to the fiber during rapid cooling.

[0039] Preparation Example 5 Preparation method of flexible zirconia fiber: The difference from Preparation Example 4 is that 0.4 kg of nano-aluminum oxide is slowly added to the zirconium oxychloride solution, and then 0.8 kg of polyethylene glycol is added, and the mixture is continuously stirred in the stirring tank to form a stable precursor solution.

[0040] Preparation Example 6 Preparation method of flexible zirconia fiber: The difference from Preparation Example 4 is that 1.2 kg of nano-aluminum oxide is slowly added to the zirconium oxychloride solution, and then 1.6 kg of polyethylene glycol is added, and the mixture is continuously stirred in the stirring tank to form a stable precursor solution.

[0041] Preparation Example 7 Method for preparing flexible zirconia fiber: Different from Preparation Example 4 in that nano-aluminum oxide is not added.

[0042] Preparation Example 8 Method for preparing flexible zirconia fiber: Different from Preparation Example 4 in that polyethylene glycol is not added. Examples

[0043] Example 1 Method for preparing an optical cable sheath material: Add 4 kg of nano-montmorillonite (Macklin reagent M813515) to deionized water and perform ultrasonic dispersion treatment at 30 kHz for 15 min using an ultrasonic treatment device to form a montmorillonite suspension; Plasticize natural rubber (Macklin reagent N909338) on an open mill, control the temperature at 55 °C, and continue for 10 minutes to soften it; Compound Tinuvin 770 and nano-titanium dioxide according to a mass ratio of 8:2 to obtain an ultraviolet light absorber; Prepare flexible zirconia fibers according to the method of Preparation Example 4, with a diameter of 2 - 4 μm and a length of 1 - 3 mm; Melt and knead 65 kg of polyvinylidene fluoride (Macklin reagent 768740) at 170 °C for 10 min; Add the montmorillonite suspension to the molten polyvinylidene fluoride, continue kneading for 10 min, then sequentially add 7 kg of flexible zirconia fibers, 13 kg of natural rubber, 8 kg of epoxidized soybean oil (Macklin reagent E808876), and 2 kg of ultraviolet light absorber, and continue kneading for 25 min; Extrude the uniformly kneaded material at a temperature of 180 °C to obtain the required optical cable sheath.

[0044] Example 2 Method for preparing an optical cable sheath material: Different from Example 1 in that a suspension containing 3 kg of nano-montmorillonite is added to 60 kg of molten polyvinylidene fluoride, continue kneading for 10 min, then sequentially add 5 kg of flexible zirconia fibers, 10 kg of natural rubber, 5 kg of epoxidized soybean oil, and 1 kg of ultraviolet light absorber, and continue kneading for 25 min.

[0045] Example 3 A preparation method of an optical cable sheath material: The difference from Example 1 is that a suspension containing 5 kg of nano-montmorillonite is added to 70 kg of molten polyvinylidene fluoride, and the mixture is further kneaded for 10 min. Then, 10 kg of flexible zirconia fibers, 15 kg of natural rubber, 10 kg of epoxidized soybean oil, and 3 kg of ultraviolet absorber are added in sequence, and the mixture is further kneaded for 25 min.

[0046] Example 4 A preparation method of an optical cable sheath material: The difference from Example 1 is that the flexible zirconia fibers are prepared according to the method of Preparation Example 5.

[0047] Example 5 A preparation method of an optical cable sheath material: The difference from Example 1 is that the flexible zirconia fibers are prepared according to the method of Preparation Example 6.

[0048] Example 6 A preparation method of an optical cable sheath material: The difference from Example 1 is that Tinuvin 770 and nano-titanium dioxide are compounded in a mass ratio of 7:2 to obtain an ultraviolet absorber.

[0049] Example 7 A preparation method of an optical cable sheath material: The difference from Example 1 is that Tinuvin 770 and nano-titanium dioxide are compounded in a mass ratio of 9:2 to obtain an ultraviolet absorber.

[0050] Example 8 A preparation method of an optical cable sheath material: The difference from Example 1 is that 6 kg of self-healing polymer is further added to the molten polyvinylidene fluoride, and the self-healing polymer is prepared according to the method of Preparation Example 1.

[0051] Example 9 A preparation method of an optical cable sheath material: The difference from Example 8 is that 4 kg of self-healing polymer is further added to the molten polyvinylidene fluoride.

[0052] Example 10 A preparation method of an optical cable sheath material: The difference from Example 8 is that 8 kg of self-healing polymer is further added to the molten polyvinylidene fluoride.

[0053] Example 11 A preparation method of an optical cable sheath material: The difference from Example 8 is that the self-healing polymer is prepared according to the method of Preparation Example 2.

[0054] Example 12 A preparation method of an optical cable sheath material: The difference from Example 8 is that the self-healing polymer is prepared according to the method of Preparation Example 3.

[0055] Comparative Example Comparative Example 1 A preparation method of an optical cable sheath material: The difference from Example 1 is that the dosage of polyvinylidene fluoride is 55 kg, the dosage of natural rubber is 23 kg, and the dosages of the other components remain unchanged.

[0056] Comparative Example 2 A preparation method of an optical cable sheath material: The difference from Example 1 is that the flexible zirconia fiber is prepared according to the method of Preparation Example 7.

[0057] Comparative Example 3 A preparation method of an optical cable sheath material: The difference from Example 1 is that the flexible zirconia fiber is prepared according to the method of Preparation Example 7.

[0058] Performance Detection Test Detection Method Place the material sample in a high-temperature aging oven, conduct 300 h of aging treatment at 80 °C and 50% humidity, and continuously irradiate with an ultraviolet lamp. Test the tensile strength and surface quality changes of the material before and after aging respectively.

[0059] Table 1 Test Data Combined with Example 1 and Comparative Example 1 and Table 1, it can be seen that PVDF provides the high strength and weather resistance of the material, ensuring its stability in harsh environments, while natural rubber supplements the flexibility of the material, making it more adaptable to bending and movement, and enhancing the impact resistance and fatigue resistance of the material. Combining 60 - 70 parts of polyvinylidene fluoride with 10 - 15 parts of natural rubber can enhance the anti-aging, anti-ultraviolet, chemical corrosion resistance and other properties of the optical cable sheath material while maintaining the flexibility and impact resistance of the material, and extending the service life of the optical cable sheath, especially in complex outdoor environments.

[0060] Combined with Example 1, 4, 5 and Comparative Examples 2 - 3 and Table 1, it can be seen that nano-aluminum oxide provides strong structural stability and anti-aging ability, while PEG increases the flexibility of the fiber, enabling the two to complement each other when used in combination. The hard characteristics of nano-aluminum oxide can enhance the mechanical strength of the fiber, while the flexible chain segments of PEG can prevent the fiber from being too brittle, making it have better impact resistance and bending resistance under external forces.

[0061] Combined with Examples 1-3 and Table 1, it can be seen that by using polyvinylidene fluoride as the matrix material, it has excellent chemical corrosion resistance, high temperature resistance and ultraviolet resistance, and can maintain stability under extreme climatic conditions. The addition of nano-montmorillonite further enhances the moisture resistance and thermal stability of the material, effectively inhibiting moisture penetration and excessive flow of polymer chains. The introduction of natural rubber and epoxidized soybean oil endows the material with good flexibility and anti-aging performance, ensuring that it can still maintain elasticity and prevent cracking under low temperature and high temperature environments. Flexible zirconia fibers improve the mechanical strength and impact resistance of the material, enhancing its high temperature resistance. The ultraviolet absorber effectively slows down the degradation of polymer chains caused by ultraviolet rays, extending the service life of the optical cable sheath. The synergistic effect of each component enables the optical cable sheath material to maintain excellent performance in harsh environments and significantly extends its service life.

[0062] Combined with Example 1 and Examples 4-7 and Table 1, it can be seen that the compounding of Tinuvin 770 and nano-titanium dioxide makes full use of the synergistic effect of organic and inorganic ultraviolet absorbers, which can not only prevent the generation of free radicals induced by ultraviolet rays from the inside, but also provide physical barrier from the outside. The dual protection effectively improves the ultraviolet resistance of the material. The compounding is carried out according to the mass ratio of (7-9):2, ensuring a reasonable balance of the two components.

[0063] Combined with Example 1 and Examples 8-12 and Table 1, it can be seen that the self-healing polymer realizes the self-healing property by introducing disulfide bonds (S-S bonds) into the polymer main chain. When the optical cable sheath material generates microcracks or damages under external force, the presence of disulfide bonds can make the material heal spontaneously, slow down the decline of material performance, and extend the service life of the optical cable.

[0064] This specific embodiment is only an interpretation of the present application, and it is not a limitation of the present application. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. An optical cable sheath material, characterized in that: The following components are included by weight: 60-70 parts of polyvinylidene fluoride, 10-15 parts of natural rubber, 3-5 parts of nano-montmorillonite, 5-10 parts of flexible zirconia fiber, 1-3 parts of anti-ultraviolet agent, and 5-10 parts of epoxidized soybean oil.

2. The optical cable sheath material according to claim 1, characterized in that: Also included are 4-8 parts of a self-healing polymer.

3. The optical cable sheath material according to claim 2, characterized in that: The preparation method of the self-healing polymer is: Mix 6-8 parts of polyethylene glycol and 2-4 parts of dimethyl dithiodibenzoate, add an initiator at 120-130°C to carry out polymerization reaction to form a polymer with disulfide bonds, add a disulfide crosslinking agent, carry out crosslinking reaction at 70-80°C, and keep warm for 2-4 hours.

4. The optical cable sheath material according to claim 1, characterized in that: The flexible zirconia fiber has a diameter of 2-4 μm and a length of 1-3 mm.

5. The optical cable sheath material according to claim 1, characterized in that: The preparation method of the flexible zirconia fiber is: Adding nano-alumina and polyethylene glycol to a zirconium oxychloride solution with a mass concentration of 40-60%, wherein the amount of nano-alumina is 2-6% of the mass of the zirconium oxychloride solution, and the amount of polyethylene glycol is 4-8% of the mass of the zirconium oxychloride solution, and mixing them evenly to obtain a precursor solution, drawing the zirconium oxychloride solution precursor solution into fibers by solution spinning technology, and then placing the fibers in ammonia water with a mass concentration of 5-10% for gelation treatment; The gelled fibers are dried at 60-100°C, and the dried fibers are pre-sintered at 300-500°C for 1-2 hours; The pre-sintered fiber is sintered at 1200-1600° C. for 1-3 hours. After sintering, the fiber is cooled to room temperature to obtain a flexible zirconia fiber.

6. The optical cable sheath material according to claim 1, characterized in that: The anti-ultraviolet agent comprises Tinuvin 770 and nano titanium dioxide, and the Tinuvin 770 and the nano titanium dioxide are compounded in a mass ratio of (7-9):

2.

7. A method for preparing an optical cable sheath material according to any one of claims 1 to 6, characterized in that: The following steps are involved: Plasticize and soften the natural rubber, control the temperature at 50-60℃, and continue for 5-10 minutes; Melt and knead polyvinylidene fluoride at 160-180°C for 5-10 minutes; Add nano-montmorillonite, flexible zirconia fiber, natural rubber, epoxidized soybean oil and anti-ultraviolet agent to the molten polyvinylidene fluoride in sequence, and continue mixing for 20-30 minutes; The uniformly mixed material is extruded at a temperature of 160-200°C to obtain the desired optical cable sheath.

8. The method for preparing the optical cable sheath material according to claim 7, characterized in that: The self-healing polymer is also added into the molten polyvinylidene fluoride.

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