Photoelectric composite aluminum alloy conductor aerospace cable and preparation method thereof

Abstract

The invention discloses a photoelectric composite aluminum alloy conductor aerospace cable and a preparation method, and belongs to the technical field of photoelectric composite cables, the cable comprises an optical fiber unit, a conductor unit, an insulating layer, an anti-electromagnetic unit and a sheath layer; the anti-electromagnetic unit is obtained by weaving double-layer metallized polyimide fibers; the double-layer metallized polyimide fiber sequentially comprises a polyimide fiber, a first metal coating and a second metal coating from inside to outside. The surface of the polyimide fiber is coated with modified polydopamine; the first metal coating is copper; and the second metal coating is silver and / or nickel. The double-layer metal coating can form a more compact metal outer layer on the surface of the polyimide fiber, the requirements of the severe external environment of aerospace are met, a conductive network with higher stability is formed, and the electromagnetic shielding effect is remarkably improved. Moreover, the polyimide fiber is coated with a polydopamine coating, so that the fiber is not damaged, and the overall high and low temperature resistance and radiation resistance can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of optoelectronic composite cables, and in particular relates to an optoelectronic composite aluminum alloy conductor aerospace cable and a preparation method thereof. Background Art

[0002] With the development of the modern aerospace industry, the requirements for cable performance are becoming increasingly stringent. In the aerospace field, cables must not only transmit power but also support efficient data communication to meet the information exchange needs of complex systems. The performance of cables is directly related to the safety and reliability of aircraft.

[0003] At the same time, in order to achieve rapid data transmission and processing, fiber optic communication functions need to be integrated. By integrating optical fiber and power transmission lines into the same cable, the installation process can be greatly simplified and the required space can be reduced. This optoelectronic composite cable can not only carry a large amount of power load, but also support high-speed data transmission, ensuring seamless connection between various electronic devices. In the aerospace field, this composite cable can effectively reduce the wiring complexity inside aircraft or satellites, and improve the reliability and efficiency of the overall system.

[0004] Although traditional copper conductor cables have good conductivity, they have problems such as heavy weight, poor flexibility, insufficient tensile strength, and limited electromagnetic shielding effect. In addition, their performance is unstable in extreme environments such as high and low temperatures and radiation, making it difficult to meet the lightweight requirements of modern aerospace equipment and the demand for high-performance cables.

[0005] Aluminum alloy conductors have significant advantages over traditional copper conductors, such as light weight and strong corrosion resistance. However, the electromagnetic shielding effect of both copper and aluminum alloy conductors is limited, and their performance is difficult to maintain stable in extreme environments. Therefore, there is an urgent need to develop an optoelectronic composite cable that is lightweight, has strong anti-electromagnetic interference capabilities, and has excellent environmental resistance. Summary of the Invention

[0006] The purpose of the present invention is to provide an optoelectronic composite aluminum alloy conductor aerospace cable and a preparation method thereof, so as to solve the problems of poor anti-electromagnetic interference capability, high and low temperature resistance and radiation resistance of the optoelectronic composite cable.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] In a first aspect, the present invention provides an optoelectronic composite aluminum alloy conductor aerospace cable, comprising an optical fiber unit, a conductor unit, an insulation layer, an anti-electromagnetic unit, and a sheath layer; the anti-electromagnetic unit is braided from a double layer of metallized polyimide fiber;

[0009] The double-layer metallized polyimide fiber comprises polyimide fiber, a first metal plating layer and a second metal plating layer from the inside out. The surface of the polyimide fiber is coated with modified polydopamine. The first metal plating layer is copper. The second metal plating layer is silver and / or nickel.

[0010] By adopting the above technical solution, the raw materials for modifying polydopamine include dopamine hydrochloride and titanium dioxide nanotubes in a mass ratio of 1: (0.1-0.2).

[0011] By adopting the above technical solution, the polyimide fiber has excellent thermal stability, mechanical properties and radiation resistance. Two metal layers are plated on the surface of the polyimide fiber. The metal plating forms a continuous conductive film on the surface of the polyimide fiber, constructing a three-dimensional conductive network, which can make the polyimide fiber have the functions of conductivity, electromagnetic shielding and static elimination. Compared with general metal fibers, it is lighter and softer. After weaving the anti-electromagnetic unit, its electromagnetic shielding effect is significantly improved.

[0012] Furthermore, the metal coating of the present invention is a double-layer metal coating. Compared to a single-layer coating, it can form a denser metal outer layer through transition with the underlying alloy, thereby improving the mechanical stability and environmental durability of the metal coating. In contrast, a single-layer coating may affect long-term stability due to weak interfacial bonding, and its radiation resistance is significantly reduced in the extreme environments of aerospace. Furthermore, the double-layer metal coating can form multiple electromagnetic barriers. The composite structure can optimize the multiple reflection and absorption paths of electromagnetic waves, thereby improving the overall electromagnetic shielding effect.

[0013] At the same time, the present invention adopts a structure in which the inner layer is a copper plating and the outer layer is a silver and / or nickel plating. Metal copper is used as a conductive substrate, which has high conductivity compared to other metal platings and reduces the overall production cost. In addition, the bonding force between the inner copper layer and the polyimide fiber is stronger, which can improve the adhesion of the metal plating on the fiber surface; the outer layer adopts metal silver and / or metal nickel with better oxidation resistance, which can better protect the inner metal layer and prevent the inner layer from oxidation, resulting in a decrease in conductivity. This structural combination can greatly improve shielding effectiveness and service life, and can maintain basic performance even in extreme environments.

[0014] However, the traditional method of metallizing polyimide fibers is mostly chemical plating. Chemical plating is an effective metallization method with a wide range of options. The resulting coating has excellent conductivity and mechanical properties. However, the surface of polyimide fibers is highly inert. Before chemical plating, the polyimide fibers must be activated and modified. The activation and modification process usually requires a long period of alkali treatment to hydrolyze the imide rings in the polyimide fibers to produce polar groups, thereby achieving a close bond with the metal coating. However, after alkali treatment, the mechanical properties of the fibers are severely degraded, making it difficult to withstand long-term extreme environmental intrusions, and the ability to resist electromagnetic interference is greatly reduced.

[0015] To address this problem, the surface of the polyimide fiber of the present invention is coated with modified polydopamine. On the one hand, the aromatic ring structure contained in the polydopamine and the benzene ring of the polyimide fiber main chain can enhance the interface bonding through π-π stacking. The hydroxyl groups contained in the polydopamine can also form a hydrogen bond network with the imide groups of the polyimide fiber, thereby inhibiting the peeling of the coating. This makes the polyimide fiber have a certain chemical activity without the need for alkali treatment and activation, and can be tightly bonded to the coating layer of the modified polydopamine.

[0016] On the other hand, the large amount of active groups such as catechol and amino groups contained in polydopamine can form coordination bonds with metal ions, enhance the nucleation density of the metal, strengthen the reduction process of the metal, and improve the reaction efficiency of the chemical plating. Moreover, the coating formed by polydopamine can form a porous structure on the surface of the polyimide fiber, thereby enhancing the mechanical interlocking effect of the metal plating, achieving a close combination of the metal plating and the polyimide fiber, and also maintaining the excellent radiation resistance and mechanical properties of the polyimide fiber without damaging the polyimide fiber body.

[0017] At the same time, the polyimide fiber coated with modified polydopamine can help the metal plating layer to be deposited more densely, improve conductivity, and enhance electromagnetic shielding effectiveness. The polydopamine coating formed by the coating can also play a protective role. During the chemical plating process, the chemical plating solution does not directly contact the polyimide fiber, but forms a coating on the surface of the modified polydopamine coating formed by the coating. In this way, the polyimide fiber can still form a close link with the metal plating layer without activation treatment, thereby giving the polyimide fiber a certain conductivity, and the mechanical strength of the polyimide fiber will not be affected.

[0018] Preferably, the titanium dioxide nanotubes are modified with tannic acid; the mass ratio of the titanium dioxide nanotubes to the tannic acid is 1:(0.4-0.6).

[0019] Preferably, the titanium dioxide nanotubes are modified according to the following method:

[0020] The titanium dioxide nanotubes are dispersed in a tannic acid aqueous solution, immersed at 40-60 DEG C for 10-12 hours, and finally centrifuged, washed and dried to obtain modified titanium dioxide nanotubes.

[0021] By adopting this technical solution, the polyimide fiber coated with modified polydopamine can form a tight bond with the metal coating even without alkaline activation, achieving conductivity while maintaining its inherent mechanical properties. Furthermore, due to its application in aerospace, the cable must also maintain excellent electromagnetic interference resistance in even extreme environments.

[0022] In addition to the above-mentioned effects, the polyimide fiber surface coated with modified polydopamine of the present invention can absorb the difference in thermal expansion coefficient between part of the polyimide fiber and the metal coating, delaying interface cracking, and at the same time, the amino group can form a stronger hydrogen bond network with the carbonyl group contained in the polyimide fiber at low temperatures, thereby improving the interface bonding force between the coating and the fiber; at the same time, the catechol group in the polydopamine can efficiently quench the active oxygen generated by irradiation, inhibiting the oxidation and fracture of the main chain of the polyimide fiber, and the dense polydopamine coating can scatter low-energy ions and reduce the irradiation energy deposition rate. It can be seen that after the polydopamine modification treatment, the anti-electromagnetic interference ability of the anti-electromagnetic unit in extreme environments can be significantly improved.

[0023] However, the polydopamine coating will gradually carbonize at higher temperatures, losing its adhesion and free radical scavenging functions, limiting its application in higher temperature scenarios. In addition, under long-term high-dose irradiation, the catechol structure of polydopamine may be oxidized, reducing the free radical scavenging efficiency, and the molecular chain may also cross-link or break. In order to further improve the effect of the polydopamine coating on the high and low temperature resistance and radiation resistance of polyimide fibers, titanium dioxide nanotubes are also added to the polydopamine.

[0024] Titanium dioxide nanotubes dispersed in the polydopamine coating can act as a physical barrier to delay the thermal decomposition of polydopamine and improve the overall high-temperature resistance. At the same time, the low shrinkage of titanium dioxide nanotubes will offset the shrinkage difference between polyimide fibers and polydopamine in low-temperature environments and reduce interfacial peeling at low temperatures.

[0025] In addition, titanium dioxide nanotubes can effectively absorb and scatter high-energy rays, reduce the breakage of the molecular chain of polydopamine, and inhibit the oxidative degradation of polydopamine, thereby improving the high-temperature degradation resistance and long-term radiation stability of polydopamine.

[0026] However, due to the poor nanodispersibility of titanium dioxide nanotubes, they tend to aggregate in the system, which in turn affects the material's performance. Therefore, further modification can be performed on the titanium dioxide nanotubes. Specifically, the present invention uses tannic acid to modify the titanium dioxide nanotubes. Tannic acid, through its abundant hydroxyl and carboxylic acid groups, forms hydrogen bonds or coordinate bonds with the hydroxyl groups on the surface of the titanium dioxide nanotubes, forming a stable coating that reduces the van der Waals forces between the nanotubes and thus inhibits aggregation.

[0027] Tannic acid also acts as a bridge. Its aromatic rings bond with the benzene rings of the polyimide fiber through π-π stacking, while the hydroxyl groups form hydrogen bonds with the imide groups of the polyimide fiber, thereby enhancing the bonding strength between the modified polydopamine coating and the polyimide fiber. The introduction of tannic acid also helps scavenge free radicals, improving overall radiation resistance and thus enhancing resistance to electromagnetic interference in extreme environments.

[0028] Preferably, the double-layer metallized polyimide fiber is prepared according to the following method:

[0029] S101. Ultrasonic cleaning of the polyimide fiber for 3 to 4 hours;

[0030] S102. Dopamine hydrochloride was added to the buffer solution and mixed to obtain a dopamine solution. Titanium dioxide nanotubes were then added and dispersed uniformly. The cleaned polyimide fiber was immersed in the mixed solution and stirred at room temperature for 12 to 15 hours. The pretreated polyimide fiber was finally washed and dried to obtain the pretreated polyimide fiber.

[0031] S103. The pretreated polyimide fiber is immersed in a chemical copper plating solution, the temperature is raised to 40 to 45 ° C, and immersed for 20 to 30 minutes to form a first metal coating;

[0032] S104. Place the polyimide fiber coated with the first metal layer in a water-soluble palladium salt solution and ultrasonically react for 30 to 40 seconds; then transfer it to a chemical silver plating solution and / or a chemical nickel plating solution, increase the temperature to 70 to 80°C, react for 2 to 5 minutes, and finally wash and dry to obtain a double-layer metallized polyimide fiber.

[0033] Preferably, the concentration of the dopamine solution is 2-4 g / L; the mass volume ratio of the polyimide fiber to the dopamine solution is 1 g: (3-5) mL.

[0034] Preferably, the water-soluble palladium salt includes a combination of one or more of palladium chloride, palladium nitrate, sodium tetrachloropalladate and palladium sulfate.

[0035] By adopting the above technical solution, the polyimide fiber is first coated and modified, polydopamine is in situ polymerized on the surface, and titanium dioxide nanotubes are dispersed to improve the high temperature resistance and long-term radiation stability of the polydopamine coating. Furthermore, the polyimide fiber coated with the modified polydopamine coating can be tightly bonded to the metal plating without alkali treatment. Finally, after two platings, two layers of metal layers are coated on the surface of the polyimide fiber, so that the polyimide fiber has a certain conductive effect. The woven anti-electromagnetic unit still has good anti-electromagnetic interference capability under extreme environments.

[0036] Preferably, the conductor unit is made of 1350 series aluminum alloy.

[0037] By adopting the above technical solution, the present invention uses 1350 series aluminum alloy to replace conventional copper conductors, which can greatly reduce the overall weight while maintaining the same conductive performance, achieve lightweight design, and significantly reduce installation and support costs. In addition, since the creep resistance of 1350 series aluminum alloy is close to that of copper conductors, the connection stability is significantly improved, and it also has excellent anti-oxidation performance and a longer service life.

[0038] Preferably, the optical fiber unit includes an optical fiber, a loose tube, a fiber reinforcement layer and a coating layer; the fiber reinforcement layer is composed of 6 to 10 aramid fibers.

[0039] Preferably, the conductor unit is composited outside the optical fiber unit by twisting.

[0040] Preferably, the raw material of the coating layer is tetrafluoroethylene-ethylene copolymer.

[0041] Preferably, the thickness of the coating layer is 0.12 to 0.20 mm.

[0042] By adopting the above technical solution, a fiber reinforcement layer is added to the outside of the optical fiber, which can effectively prevent the optical fiber from breaking due to stretching or bending, and reduce the micro-bending loss of the optical fiber. The coating layer made of tetrafluoroethylene-ethylene copolymer can provide a certain degree of compressive flexibility, which can better protect the internal optical fiber.

[0043] Preferably, the raw material of the insulating layer and the sheath layer is tetrafluoroethylene-ethylene copolymer.

[0044] More preferably, the thickness of the insulating layer is 0.12 to 0.20 mm; and the thickness of the sheath layer is 0.15 to 0.25 mm.

[0045] In a second aspect, the present invention provides a method for preparing an optoelectronic composite aluminum alloy conductor aerospace cable, characterized in that it includes the following process steps:

[0046] S201 in the optical fiber jacket loose tube, the loose tube extrusion coating tetrafluoroethylene - ethylene copolymer to form a coating layer, and the introduction of aramid fiber during the extrusion process, the loose tube and the coating around the composition of the fiber reinforcement layer to obtain an optical fiber unit;

[0047] S202. With the optical fiber unit as the center, 1350 series aluminum alloy is twisted outside the optical fiber unit to obtain a conductor unit, and the conductor unit is insulated by extruding tetrafluoroethylene - ethylene copolymer and radiation cross-linking to form an insulating layer;

[0048] S203. The double-layer metallized polyimide fiber is woven to obtain an anti-electromagnetic unit, wherein the braiding density is 85 to 95%, the braiding angle is 40 to 50 degrees, and the anti-electromagnetic unit is coated on the outside of the insulated core after the cable is formed;

[0049] S204. Insulation extruded tetrafluoroethylene-ethylene copolymer, coated on the outside of the anti-electromagnetic unit, radiation cross-linked to form a sheath layer.

[0050] Beneficial effects of the present invention:

[0051] 1. The optoelectronic composite aluminum alloy conductor aerospace cable of the present invention is provided with an anti-electromagnetic unit, which is composed of a double-layer metallized polyimide fiber. The double-layer metal plating can form a denser metal outer layer through a transition effect with the underlying alloy, meeting the harsh external environment of aerospace, forming a more stable conductive network, and significantly improving the electromagnetic shielding effect.

[0052] 2. The polyimide fiber in the anti-electromagnetic unit of the present invention is not activated by alkali treatment before being plated with the metal coating, but is coated with a polydopamine coating on the surface, which can better maintain the fiber structure and mechanical properties, and can also enhance the bonding force between the polyimide fiber and the metal coating. Moreover, polydopamine combined with titanium dioxide nanotubes can greatly improve the overall high and low temperature resistance and radiation resistance, and enhance the anti-electromagnetic interference ability of the anti-electromagnetic unit in extreme environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The present invention will be further described below with reference to the accompanying drawings.

[0054] Figure 1 This is a schematic structural diagram of the optoelectronic composite aluminum alloy conductor aerospace cable in Example 1 of the present invention;

[0055] In the figure: 1. Optical fiber unit; 2. Conductor unit; 3. Insulation layer; 4. Anti-electromagnetic unit; 5. Sheath layer. DETAILED DESCRIPTION

[0056] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0057] Preparation Example

[0058] Preparation Example 1: A double-layer metallized polyimide fiber was prepared according to the following method:

[0059] S101. Ultrasonic cleaning of polyimide fibers (single filament diameter 15 μm) for 4 h;

[0060] S102. Add dopamine hydrochloride to the Tris-HCl buffer solution and mix well to obtain a dopamine solution, wherein the concentration of the dopamine solution is 3 g / L; then add titanium dioxide nanotubes, wherein the mass ratio of dopamine hydrochloride to titanium dioxide nanotubes is 1:0.15;

[0061] After uniform dispersion, the cleaned polyimide fibers were immersed in the mixed solution, where the mass volume ratio of polyimide fibers to dopamine solution was 1g:4mL. The mixture was stirred at room temperature for 12 hours, and finally washed and dried to obtain the pretreated polyimide fibers.

[0062] S103. The pretreated polyimide fiber is immersed in a chemical copper plating solution, the temperature is raised to 45 ° C, and immersed for 20 minutes to form a first metal coating;

[0063] S104. Place the polyimide fiber coated with the first metal layer in palladium chloride and ultrasonically react for 30 seconds; then transfer it to a chemical silver plating solution, increase the temperature to 80°C, react for 4 minutes, and finally wash and dry to obtain a double-layer metallized polyimide fiber.

[0064] Preparation Example 2, a double-layer metallized polyimide fiber, differs from Preparation Example 1 only in that the mass ratio of dopamine hydrochloride to titanium dioxide nanotubes is 1:0.1; and the mass volume ratio of polyimide fiber to dopamine solution is 1 g:3 mL.

[0065] Preparation Example 3, a double-layer metallized polyimide fiber, differs from Preparation Example 1 only in that the mass ratio of dopamine hydrochloride to titanium dioxide nanotubes is 1:0.2; and the mass volume ratio of polyimide fiber to dopamine solution is 1 g:5 mL.

[0066] Preparation Example 4, a double-layer metallized polyimide fiber, differs from Preparation Example 1 only in that an equal amount of chemical nickel plating solution is used to replace the chemical silver plating solution.

[0067] Preparation Example 5, a double-layer metallized polyimide fiber, differs from Preparation Example 1 only in that the chemical silver plating solution is replaced by a mixture of an equal amount of chemical nickel plating solution and a chemical silver plating solution in a mass ratio of 0.4:0.6.

[0068] Preparation Example 6, a double-layer metallized polyimide fiber, differs from Preparation Example 1 only in that the mass ratio of dopamine hydrochloride to titanium dioxide nanotubes is 1:0.05.

[0069] Preparation Example 7, a double-layer metallized polyimide fiber, differs from Preparation Example 1 only in that the mass ratio of dopamine hydrochloride to titanium dioxide nanotubes is 1:0.3.

[0070] Preparation Example 8, a double-layer metallized polyimide fiber, differs from Preparation Example 1 only in that the titanium dioxide nanotubes are replaced with an equal amount of titanium dioxide nanotubes modified with tannic acid, wherein the titanium dioxide nanotubes modified with tannic acid are prepared according to the following method:

[0071] Titanium dioxide nanotubes were dispersed in a tannic acid aqueous solution, wherein the mass ratio of titanium dioxide nanotubes to tannic acid was 1:0.5; the solution was immersed at 45°C for 12 hours, and finally the modified titanium dioxide nanotubes were obtained by centrifugation, washing and drying.

[0072] Preparation Example 9, a double-layer metallized polyimide fiber, is different from Preparation Example 1 only in that titanium dioxide nanotubes are not added in step S102.

[0073] Preparation Example 10: A single-layer metallized polyimide fiber was prepared according to the following method:

[0074] S101. Ultrasonic cleaning of polyimide fibers (single filament diameter 15 μm) for 4 h;

[0075] S102. Add dopamine hydrochloride to the Tris-HCl buffer solution and mix well to obtain a dopamine solution, wherein the concentration of the dopamine solution is 3 g / L; then add titanium dioxide nanotubes, wherein the mass ratio of dopamine hydrochloride to titanium dioxide nanotubes is 1:0.15;

[0076] After uniform dispersion, the cleaned polyimide fibers were immersed in the mixed solution, where the mass volume ratio of polyimide fibers to dopamine solution was 1g:4mL. The mixture was stirred at room temperature for 12 hours, and finally washed and dried to obtain the pretreated polyimide fibers.

[0077] S103. Immerse the pretreated polyimide fiber in a chemical silver plating solution, increase the temperature to 80° C., react for 10 minutes, and finally wash and dry to obtain a single-layer metallized polyimide fiber.

[0078] Preparation Example 11: A single-layer metallized polyimide fiber was prepared according to the following method:

[0079] S101. Ultrasonic cleaning of polyimide fibers (single filament diameter 15 μm) for 4 h;

[0080] S102. Add dopamine hydrochloride to the Tris-HCl buffer solution and mix well to obtain a dopamine solution, wherein the concentration of the dopamine solution is 3 g / L; then add titanium dioxide nanotubes, wherein the mass ratio of dopamine hydrochloride to titanium dioxide nanotubes is 1:0.15;

[0081] After uniform dispersion, the cleaned polyimide fibers were immersed in the mixed solution, where the mass volume ratio of polyimide fibers to dopamine solution was 1g:4mL. The mixture was stirred at room temperature for 12 hours, and finally washed and dried to obtain the pretreated polyimide fibers.

[0082] S103. Immerse the pretreated polyimide fiber in a chemical copper plating solution, increase the temperature to 45° C., immerse for 20 minutes, and finally wash and dry to obtain a double-layer metallized polyimide fiber.

[0083] Preparation Example 12: A double-layer metallized polyimide fiber was prepared according to the following method:

[0084] S101. Ultrasonic cleaning of polyimide fibers (single filament diameter 15 μm) for 4 h;

[0085] S102. The cleaned polyimide fiber was immersed in a NaOH solution for 20 min, the temperature was raised to 40°C, and the fiber was treated in a nickel chloride solution for 5 min for ion exchange, followed by treatment in a NaBH4 solution for 3 min for ion reduction, and finally washed and dried to obtain an activated polyimide fiber.

[0086] S103. The activated polyimide fiber is immersed in a chemical copper plating solution, the temperature is raised to 45 ° C, and immersed for 20 minutes to form a first metal coating;

[0087] S104. Place the polyimide fiber coated with the first metal layer in palladium chloride and ultrasonically react for 30 seconds; then transfer it to a chemical silver plating solution, increase the temperature to 80°C, react for 4 minutes, and finally wash and dry to obtain a double-layer metallized polyimide fiber.

[0088] Example

[0089] Example 1: An optoelectronic composite aluminum alloy conductor aerospace cable is prepared according to the following process steps:

[0090] S201. A loose tube is formed in the outer jacket of the optical fiber, and a tetrafluoroethylene-ethylene copolymer is extruded outside the loose tube to form a coating layer. The average thickness of the coating layer is 0.14 mm, and eight aramid fibers are introduced during the extrusion process. The fiber reinforcement layer is formed between the loose tube and the coating layer to obtain an optical fiber unit.

[0091] S202. With the optical fiber unit as the center, 1350 series aluminum alloy is twisted outside the optical fiber unit to obtain a conductor unit. The conductor unit is insulated by extruding tetrafluoroethylene - ethylene copolymer and radiation cross-linking to form an insulating layer. The average thickness of the insulating layer is 0.15mm.

[0092] S203. The double-layer metallized polyimide fiber prepared in Preparation Example 1 is braided to obtain an anti-electromagnetic unit, wherein the braiding density is 90%, the braiding angle is 45°, and the anti-electromagnetic unit is coated on the outside of the insulated core after the cable is formed;

[0093] S204. Insulated extruded tetrafluoroethylene-ethylene copolymer is coated on the outside of the anti-electromagnetic unit and radiation cross-linked to form a sheath layer with an average thickness of 0.2mm.

[0094] Example 2, an optoelectronic composite aluminum alloy conductor aerospace cable, differs from Example 1 only in that the double-layer metallized polyimide fiber prepared in Preparation Example 2 is used to replace the double-layer metallized polyimide fiber prepared in Preparation Example 1.

[0095] Example 3, an optoelectronic composite aluminum alloy conductor aerospace cable, differs from Example 1 only in that the double-layer metallized polyimide fiber prepared in Preparation Example 1 is replaced by an equal amount of the double-layer metallized polyimide fiber prepared in Preparation Example 3.

[0096] Example 4, an optoelectronic composite aluminum alloy conductor aerospace cable, differs from Example 1 only in that the double-layer metallized polyimide fiber prepared in Preparation Example 1 is replaced by an equal amount of the double-layer metallized polyimide fiber prepared in Preparation Example 4.

[0097] Example 5, an optoelectronic composite aluminum alloy conductor aerospace cable, differs from Example 1 only in that the double-layer metallized polyimide fiber prepared in Preparation Example 1 is replaced by an equal amount of the double-layer metallized polyimide fiber prepared in Preparation Example 5.

[0098] Example 6, an optoelectronic composite aluminum alloy conductor aerospace cable, differs from Example 1 only in that the double-layer metallized polyimide fiber prepared in Preparation Example 1 is replaced by an equal amount of the double-layer metallized polyimide fiber prepared in Preparation Example 6.

[0099] Example 7, an optoelectronic composite aluminum alloy conductor aerospace cable, differs from Example 1 only in that the double-layer metallized polyimide fiber prepared in Preparation Example 7 is used to replace the double-layer metallized polyimide fiber prepared in Preparation Example 1.

[0100] Example 8, an optoelectronic composite aluminum alloy conductor aerospace cable, differs from Example 1 only in that the double-layer metallized polyimide fiber prepared in Preparation Example 8 is used to replace the double-layer metallized polyimide fiber prepared in Preparation Example 1.

[0101] Comparative Example

[0102] Comparative Example 1, an optoelectronic composite aluminum alloy conductor aerospace cable, differs from Example 1 only in that the double-layer metallized polyimide fiber prepared in Preparation Example 9 is used in place of the double-layer metallized polyimide fiber prepared in Preparation Example 1.

[0103] Comparative Example 2, an optoelectronic composite aluminum alloy conductor aerospace cable, differs from Example 1 only in that the double-layer metallized polyimide fiber prepared in Preparation Example 1 is replaced by an equal amount of the single-layer metallized polyimide fiber prepared in Preparation Example 10.

[0104] Comparative Example 3, an optoelectronic composite aluminum alloy conductor aerospace cable, differs from Example 1 only in that the double-layer metallized polyimide fiber prepared in Preparation Example 1 is replaced by an equal amount of the single-layer metallized polyimide fiber prepared in Preparation Example 11.

[0105] Comparative Example 4, an optoelectronic composite aluminum alloy conductor aerospace cable, differs from Example 1 only in that the double-layer metallized polyimide fiber prepared in Preparation Example 1 is replaced by an equal amount of the double-layer metallized polyimide fiber prepared in Preparation Example 12.

[0106] Comparative Example 5, an optoelectronic composite aluminum alloy conductor aerospace cable, differs from Example 1 only in that, in step S202, aramid fiber is not introduced outside the optical fiber.

[0107] Performance testing

[0108] 1. Mechanical properties: The tensile strength of the cable obtained in this application was tested according to the relevant records in GB / T 2951-2008 "General test methods for insulation and sheathing materials of electric and optical cables Part 11: Thickness and dimensions measurement - Mechanical properties test". The test results are shown in Table 1.

[0109] 2. Anti-electromagnetic interference capability test: Use a vector network analyzer to test the electromagnetic shielding effectiveness in the frequency range of 8Hz-12.5Hz;

[0110] Take the cable samples of the embodiment and the comparative example, treat them at 200° C. for 4 hours, and calculate the electromagnetic shielding effectiveness retention rate (%) after heat treatment;

[0111] Cable samples of the embodiment and comparative example were taken and treated under irradiation for 7 days, and the electromagnetic shielding effectiveness retention rate (%) after irradiation treatment was calculated.

[0112] The above test results are shown in Table 2.

[0113] Table 1 Mechanical properties test results

[0114]

[0115] Table 2 Anti-electromagnetic interference ability test results

[0116]

[0117] According to Tables 1 and 2, in combination with Example 1, Example 6, Example 7, and Comparative Example 1, it can be seen that the electromagnetic shielding effectiveness of Example 6, Example 7, and Comparative Example 1 has decreased compared to Example 1, with the decrease in Comparative Example 1 being more significant. This indicates that the anti-electromagnetic interference capabilities of Example 6, Example 7, and Comparative Example 1, as well as the stability of their anti-electromagnetic interference capabilities under extreme environments, have all decreased compared to Example 1. The reason for this is that the amount of titanium dioxide nanotubes added to the modified polydopamine coated with the double-layer metallized polyimide fiber of the anti-electromagnetic unit in Example 6, Example 7, and Comparative Example 1 was adjusted out of range. A small amount of addition did not improve stability sufficiently. Comparative Example 1, which did not add titanium dioxide nanotubes, had a more significant performance decrease. A large amount of addition would easily cause agglomeration, both of which would lead to a decrease in the overall performance of the cable.

[0118] Combining Example 1 and Example 8, it can be seen that the electromagnetic shielding effectiveness of Example 8 is increased compared to Example 1. The reason is that the titanium dioxide nanotubes added to the double-layer metallized polyimide fiber in Example 8 are modified with tannic acid, which enhances the dispersibility and improves the interfacial bonding strength between the fibers. It can also synergistically help improve the radiation resistance, thereby improving the overall stability.

[0119] Combining Example 1, Comparative Example 2 and Comparative Example 3, it can be seen that the electromagnetic shielding effectiveness of Comparative Example 2 and Comparative Example 3 is reduced compared with Example 1. The reason is that the polyimide fibers in Comparative Example 2 and Comparative Example 3 are plated with a single layer of metal, which has weaker interface bonding strength and poor long-term stability compared to double-layer metallization, especially in extreme environments, and the anti-electromagnetic interference ability decreases rapidly.

[0120] Combining Example 1 and Comparative Example 4, it can be seen that the tensile properties and anti-electromagnetic interference ability of Comparative Example 4 are lower than those of Example 1. The reason is that Comparative Example 4 uses alkali treatment to activate the polyimide fiber, which has a greater impact on the mechanical properties of the fiber itself, which is reflected in the cable. The tensile strength will decrease, and there is a lack of modified polydopamine to improve the fiber's resistance to high and low temperatures and radiation resistance, and the overall stability is reduced.

[0121] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0122] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An optoelectronic composite aluminum alloy conductor aerospace cable, characterized in that: It includes an optical fiber unit, a conductor unit, an insulating layer, an anti-electromagnetic unit and a sheath layer; the anti-electromagnetic unit is woven from a double layer of metallized polyimide fiber; The double-layer metallized polyimide fiber comprises polyimide fiber, a first metal plating layer and a second metal plating layer from the inside out; the surface of the polyimide fiber is coated with modified polydopamine; the first metal plating layer is copper; and the second metal plating layer is silver and / or nickel.

2. The optoelectronic composite aluminum alloy conductor aerospace cable according to claim 1, characterized in that: The raw materials of the modified polydopamine include dopamine hydrochloride and titanium dioxide nanotubes in a mass ratio of 1: (0.1-0.2).

3. The optoelectronic composite aluminum alloy conductor aerospace cable according to claim 2, characterized in that: The titanium dioxide nanotubes are modified with tannic acid; and the mass ratio of the titanium dioxide nanotubes to tannic acid is 1:(0.4-0.6).

4. The optoelectronic composite aluminum alloy conductor aerospace cable according to claim 3, characterized in that: The titanium dioxide nanotubes are modified according to the following method: The titanium dioxide nanotubes are dispersed in a tannic acid aqueous solution, immersed at 40-60 DEG C for 10-12 hours, and finally centrifuged, washed and dried to obtain modified titanium dioxide nanotubes.

5. The optoelectronic composite aluminum alloy conductor aerospace cable according to claim 2, characterized in that: The double-layer metallized polyimide fiber is prepared according to the following method: S101. Ultrasonic cleaning of the polyimide fiber for 3 to 4 hours; S102. Dopamine hydrochloride was added to the buffer solution and mixed to obtain a dopamine solution. Titanium dioxide nanotubes were then added and dispersed uniformly. The cleaned polyimide fiber was immersed in the mixed solution and stirred at room temperature for 12 to 15 hours. The pretreated polyimide fiber was finally washed and dried to obtain the pretreated polyimide fiber. S103. The pretreated polyimide fiber is immersed in a chemical copper plating solution, the temperature is raised to 40 to 45 ° C, and immersed for 20 to 30 minutes to form a first metal coating; S104. Place the polyimide fiber coated with the first metal layer in a water-soluble palladium salt solution and ultrasonically react for 30 to 40 seconds; then transfer it to a chemical silver plating solution and / or a chemical nickel plating solution, increase the temperature to 70 to 80°C, react for 2 to 5 minutes, and finally wash and dry to obtain a double-layer metallized polyimide fiber.

6. The optoelectronic composite aluminum alloy conductor aerospace cable according to claim 5, characterized in that: The concentration of the dopamine solution is 2-4 g / L; the mass volume ratio of the polyimide fiber to the dopamine solution is 1 g: (3-5) mL.

7. The optoelectronic composite aluminum alloy conductor aerospace cable according to claim 1, characterized in that: The conductor unit is made of 1350 series aluminum alloy.

8. The optoelectronic composite aluminum alloy conductor aerospace cable according to claim 1, characterized in that: The optical fiber unit comprises an optical fiber, a loose tube, a fiber reinforcement layer and a coating layer; the fiber reinforcement layer is composed of 6 to 10 aramid fibers.

9. The optoelectronic composite aluminum alloy conductor aerospace cable according to claim 1, characterized in that: The raw materials of the insulating layer and the sheath layer are tetrafluoroethylene-ethylene copolymer.

10. A method for preparing an optoelectronic composite aluminum alloy conductor aerospace cable according to any one of claims 1 to 9, characterized in that: The process steps include: S201 in the optical fiber jacket loose tube, the loose tube extrusion coating tetrafluoroethylene - ethylene copolymer to form a coating layer, and the introduction of aramid fiber during the extrusion process, the loose tube and the coating around the composition of the fiber reinforcement layer to obtain an optical fiber unit; S202. With the optical fiber unit as the center, 1350 series aluminum alloy is twisted outside the optical fiber unit to obtain a conductor unit, and the conductor unit is insulated by extruding tetrafluoroethylene - ethylene copolymer and radiation cross-linking to form an insulating layer; S203. The double-layer metallized polyimide fiber is woven to obtain an anti-electromagnetic unit, wherein the braiding density is 85 to 95%, the braiding angle is 40 to 50 degrees, and the anti-electromagnetic unit is coated on the outside of the insulated core after the cable is formed; S204. Insulation extruded tetrafluoroethylene-ethylene copolymer, coated on the outside of the anti-electromagnetic unit, radiation cross-linked to form a sheath layer.

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