Self-repairing anti-twisting shielding composite cable

Abstract

The invention discloses a self-repairing anti-twisting shielding composite cable, and relates to the technical field of cables, the self-repairing anti-twisting shielding composite cable comprises a conductor, an insulating layer, a shielding layer and an outer sheath which are sequentially sleeved from inside to outside, and the insulating layer and / or the outer sheath are / is obtained by extruding a self-repairing polyurethane elastomer; the self-repairing polyurethane elastomer is prepared from the following components in parts by weight: 100 parts of soft-segment polyol, 40 to 80 parts of isophorone diisocyanate, 12 to 20 parts of a chain extender containing disulfide bonds and 5 to 12 parts of a chain extender containing ureido, and the soft-segment polyol is selected from at least one of polytetrahydrofuran ether glycol and amino-terminated polydimethylsiloxane. The self-repairing anti-twisting shielding composite cable is high in self-repairing capacity, excellent in anti-twisting performance and stable in shielding performance.

Description

Technical Field

[0001] This invention relates to the field of cable technology, and in particular to a self-healing, anti-kink shielded composite cable. Background Technology

[0002] Existing shielded composite cables mostly use traditional thermoplastic polyurethane (TPU), polyvinyl chloride (PVC), or silicone rubber for their insulation and outer sheath. These cables exhibit good electrical performance and shielding effectiveness under static or low-frequency bending conditions, but they suffer from the following main drawbacks: Under long-term frequent torsion or external mechanical damage, the insulation layer and outer sheath are prone to cracks, scratches or damage, resulting in decreased insulation performance, exposure or failure of the shielding layer, which in turn leads to increased electromagnetic interference, signal transmission failure, and even short circuit risk. The aforementioned damage is difficult to repair immediately. Existing technologies mostly rely on manual inspection and replacement of the entire cable, resulting in high maintenance costs, long downtime, and low efficiency. Due to the aforementioned defects, existing shielded composite cables cannot achieve long-term stable operation in high-dynamic application scenarios such as robots, cable chain systems, and automated equipment that require frequent bending, torsion, and mechanical damage, thus limiting their widespread application in these fields. Summary of the Invention

[0003] To solve the above-mentioned technical problems, the present invention provides a self-healing anti-kink shielded composite cable, the specific technical solution of which is as follows: A self-healing anti-kink shielded composite cable includes, from the inside out, a conductor, an insulation layer, a shielding layer, and an outer sheath, wherein the insulation layer and / or the outer sheath are extruded from a self-healing polyurethane elastomer; by weight, the self-healing polyurethane elastomer is made of the following components: 100 parts of soft segment polyol, 40-80 parts of isophorone diisocyanate, 12-20 parts of a chain extender containing disulfide bonds, and 5-12 parts of a chain extender containing urea groups, wherein the soft segment polyol is selected from at least one of polytetrahydrofuran ether diol and amino-terminated polydimethylsiloxane.

[0004] Preferably: The disulfide-containing chain extender is selected from at least one of bis(2-hydroxyethyl) disulfide, 2,2'-dithiodiethanol, and 3,3'-dithiodipropanol; The urea-containing chain extender is selected from at least one of diethylenetriamine, isophorone diamine, and 4,4'-diaminodicyclohexylmethane.

[0005] Preferably, the self-healing polyurethane elastomer is prepared by the following steps: S1. Soft segment polyol and isophorone diisocyanate are reacted at 70~100℃ for 2~4 hours under inert gas protection to obtain a prepolymer with terminal isocyanate groups; S2. Add a chain extender containing disulfide bonds and a chain extender containing urea groups to the prepolymer, and continue the reaction at 60~80°C for 4~10 hours to obtain the self-healing polyurethane elastomer.

[0006] Preferably, the self-healing anti-kink shielded composite cable is prepared by the following steps: S10. After melting the self-healing polyurethane elastomer, a first melt is formed. The first melt is extruded and coated onto the outer surface of the conductor to form an insulating layer. S20. Copper wire braid and aluminum foil composite tape are sequentially applied to the outer surface of the insulation layer to form a shielding layer; S30. After melting the self-healing polyurethane elastomer, a second melt is formed. The second melt is extruded and coated on the outer surface of the shielding layer to form an outer sheath.

[0007] Preferably: In step S10, the extrusion temperature is 140~190℃ and the die head temperature is 170~190℃; In step S30, the extrusion temperature is 130~210℃, the screw speed is 20~60rpm, and the traction speed is 10~40m / min.

[0008] Preferably, the second melt also contains surface-functionalized silver-plated carbon fibers.

[0009] Preferably, the surface-functionalized silver-plated carbon fiber is prepared by the following steps: S100. Surface activation treatment is applied to the carbon fiber; S200. Chemical silver plating is performed on the surface-activated carbon fiber to obtain silver-plated carbon fiber; S300. The silver-plated carbon fiber is subjected to surface functionalization treatment to obtain surface-functionalized silver-plated carbon fiber.

[0010] Preferably: In step S100, the surface activation treatment is selected from at least one of nitric acid oxidation treatment, plasma treatment, or ozone treatment; In step S200, the chemical silver plating includes sequential sensitization, activation, and chemical reduction silver plating processes; In step S300, the surface functionalization treatment uses a silane coupling agent to modify the surface of silver-plated carbon fibers. The silane coupling agent is selected from at least one of silane coupling agents containing amino or epoxy groups.

[0011] Preferably, the conductor is formed by stranding or re-stranding multiple strands of tin-plated copper wire.

[0012] Preferably, the shielding layer comprises a copper wire braided layer and an aluminum foil composite strip, wherein the braiding density of the copper wire braided layer is not less than 85%.

[0013] The self-healing anti-kink shielded composite cable provided by this invention has the following beneficial effects: Strong self-repairing ability The self-healing polyurethane elastomer, which utilizes dynamic disulfide bonds and multi-strength hydrogen bonds, can achieve efficient self-repair after damage at room temperature or under slight heating conditions. It has high repair efficiency and effectively solves the problem of manual replacement after damage to traditional cables, significantly reducing maintenance costs and downtime.

[0014] Excellent anti-kink properties The dynamic bond energy dissipation mechanism, combined with highly flexible soft segments, enables the cable to withstand high-frequency torsion and bending, significantly improving the cable's durability and reliability in dynamic applications such as robots and cable chains.

[0015] Stable shielding performance The rapid structural recovery of self-healing polyurethane elastomers after damage prevents the shielding layer from exposure or damage, maintains stable electromagnetic shielding effectiveness, and solves the problem of shielding failure after damage to existing cables. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0017] Figure 1 A schematic cross-sectional view of the self-healing anti-kink shielded composite cable provided for an embodiment of the present invention.

[0018] Figure Labels 1-Conductor; 2-Insulation layer; 3-Shielding layer; 4-Outer sheath. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings. The description in this part is only exemplary and explanatory, and should not be used to limit the scope of protection of the present invention in any way.

[0020] It should be noted that similar labels in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] Please see Figure 1This embodiment provides a self-healing anti-kink shielded composite cable, comprising a conductor 1, an insulation layer 2, a shielding layer 3, and an outer sheath 4 sequentially fitted from the inside out. The insulation layer 2 and / or the outer sheath 4 are obtained by extrusion of a self-healing polyurethane elastomer. By weight, the self-healing polyurethane elastomer is made of the following components: 100 parts of soft segment polyol, 40-80 parts of isophorone diisocyanate, 12-20 parts of a chain extender containing disulfide bonds, and 5-12 parts of a chain extender containing urea groups. The soft segment polyol is selected from at least one of polytetrahydrofuran ether diol and amino-terminated polydimethylsiloxane.

[0022] This embodiment employs a polyurethane network structure based on the synergistic effect of multi-strength hydrogen bonds and dynamic disulfide bonds. During stress, weak hydrogen bonds break first, dissipating energy and preventing crack propagation; strong hydrogen bonds and dynamic disulfide bonds maintain the overall structural integrity of the network. When the material suffers mechanical damage (such as scratches or cracks), the disulfide bonds in the damaged area undergo a reversible exchange reaction, while hydrogen bonds reform, enabling spontaneous repair at room temperature or under slight heating conditions, thereby restoring the material's mechanical and insulating properties.

[0023] Soft segment polyols (PTMG or aminoPDMS) endow materials with high elongation and low modulus characteristics. Combined with the energy dissipation mechanism of dynamic bonds, they enable the cable to effectively disperse stress during repeated torsion and bending, avoiding permanent deformation or cracking caused by local stress concentration, thereby achieving high kink resistance.

[0024] The shielding layer (copper wire braid + aluminum foil composite tape) provides initial high shielding effectiveness. When the outer sheath or insulation layer is damaged, the rapid recovery capability of the self-healing polyurethane elastomer enables the material structure and density of the damaged area to be quickly rebuilt, preventing the shielding layer from being exposed or failing due to damage to the outer sheath, thereby ensuring the long-term stability of electromagnetic shielding effectiveness.

[0025] Through the above-mentioned material design and structural combination, this embodiment can achieve self-repair after the cable is mechanically damaged, while maintaining excellent anti-kink performance and shielding stability, significantly improving the service life and reliability of the cable in high dynamic environments.

[0026] The self-healing, anti-kink shielded composite cable provided in this embodiment has the following beneficial effects: Strong self-repairing ability The self-healing polyurethane elastomer, which utilizes dynamic disulfide bonds and multi-strength hydrogen bonds, can achieve efficient self-repair after damage at room temperature or under slight heating conditions. It has high repair efficiency and effectively solves the problem of manual replacement after damage to traditional cables, significantly reducing maintenance costs and downtime.

[0027] Excellent anti-kink properties The dynamic bond energy dissipation mechanism, combined with highly flexible soft segments, enables the cable to withstand high-frequency torsion and bending, significantly improving the cable's durability and reliability in dynamic applications such as robots and cable chains.

[0028] Stable shielding performance The rapid structural recovery of self-healing polyurethane elastomers after damage prevents the shielding layer from exposure or damage, maintains stable electromagnetic shielding effectiveness, and solves the problem of shielding failure after damage to existing cables.

[0029] Furthermore: The chain extender containing disulfide bonds is selected from at least one of bis(2-hydroxyethyl) disulfide, 2,2'-dithiodiethanol, and 3,3'-dithiodipropanol.

[0030] The urea-containing chain extender is selected from at least one of diethylenetriamine, isophorone diamine, and 4,4'-diaminodicyclohexylmethane.

[0031] Specifically, this embodiment achieves the synergistic effect of dynamic disulfide bonds and multi-strength hydrogen bonds by introducing disulfide-bonded chain extenders and urea-based chain extenders with specific structures into the polyurethane network. The disulfide-bonded chain extenders (such as bis(2-hydroxyethyl) disulfide) introduce reversible disulfide bonds (-SS-) during polymerization, endowing the material with dynamic reversibility. When damage occurs, the disulfide bonds can undergo reversible exchange reactions at room temperature or under slight heating conditions, promoting molecular chain rearrangement and recombination in the crack region, achieving self-repair. The urea-based chain extenders (such as diethylenetriamine, isophorone diamine, etc.) introduce urea bonds (-NH-CO-NH-), forming a high-density network of strong hydrogen bonds. These, along with weak hydrogen bonds, work together to dissipate energy when under stress, while the strong hydrogen bonds maintain structural integrity, further enhancing the material's toughness and crack propagation resistance.

[0032] The specific selection of the two chain extenders mentioned above ensures both the high dynamic activity of disulfide bonds and the strength and stability of the hydrogen bond network, thereby achieving efficient self-healing and anti-kink properties without sacrificing mechanical properties.

[0033] Furthermore, the self-healing polyurethane elastomer is prepared through the following steps: S1. Soft segment polyol and isophorone diisocyanate are reacted at 70-100°C for 2-4 hours under inert gas protection to obtain a prepolymer with terminal isocyanate groups.

[0034] S2. Add a chain extender containing disulfide bonds and a chain extender containing urea groups to the prepolymer, and continue the reaction at 60~80℃ for 4~10 hours to obtain a self-healing polyurethane elastomer.

[0035] Specifically, this embodiment uses a classic two-step bulk polymerization process to prepare self-healing polyurethane elastomers: Step 1: The soft segment polyol reacts with IPDI at 70-100℃ to first generate a prepolymer with terminal isocyanate groups. This step uses a moderate temperature to avoid side reactions (such as isocyanate self-polymerization) and ensures that the prepolymer has uniform molecular weight and high end-group activity, providing a good foundation for subsequent chain extension reactions.

[0036] Step 2: Add chain extenders containing disulfide bonds and urea groups at 60~80℃ to initiate a chain extension reaction, forming a network structure with synergistic effects of multi-strength hydrogen bonds and dynamic disulfide bonds. The lower reaction temperature (60~80℃) helps control the reaction rate, avoids excessively rapid viscosity increases that would make stirring difficult, and ensures the uniform introduction of disulfide and urea bonds, thus constructing a stable dynamic network.

[0037] The two-step process described above achieves effective separation of soft and hard segments, efficient embedding of dynamic bonds, and uniformity of the molecular network, resulting in a final material with high elongation, high toughness, and efficient self-healing capabilities.

[0038] Furthermore, the self-healing anti-kink shielded composite cable is prepared through the following steps: S10. After melting the self-healing polyurethane elastomer, a first melt is formed. The first melt is extruded and coated on the outer surface of the conductor 1 to form an insulating layer 2.

[0039] S20. Copper wire braid and aluminum foil composite tape are sequentially applied to the outer surface of the insulation layer 2 to form the shielding layer 3.

[0040] S30. After melting the self-healing polyurethane elastomer, a second melt is formed. The second melt is extruded and coated on the outer surface of the shielding layer 3 to form the outer sheath 4.

[0041] Specifically, this implementation method employs a standard cable multilayer extrusion and shielding composite process, using self-healing polyurethane elastomer for molding the insulation layer and outer sheath respectively: In step S10, the self-healing polyurethane elastomer is uniformly coated onto the highly flexible conductor through melt extrusion, forming a dense insulating layer. The material's high elongation and low modulus characteristics give it good flowability and coating properties during extrusion, resulting in a tight bond with the conductor after molding.

[0042] In step S20, copper wire braid and aluminum foil composite tape are sequentially applied outside the insulation layer to form a high-density shielding layer. The copper wire braid provides flexible shielding, while the aluminum foil composite tape enhances the low-frequency shielding effect. The combination of the two forms a multi-layer shielding structure, ensuring effective suppression of electromagnetic interference.

[0043] Step S30 involves re-melting and extruding the self-healing polyurethane elastomer to coat the shielding layer, forming the outer sheath. The outer sheath and the inner insulation layer are made of the same material, have similar coefficients of thermal expansion and interfacial compatibility, thus avoiding interlayer delamination or stress concentration.

[0044] The entire process makes full use of the thermoplastic processing characteristics of self-healing polyurethane, making the overall cable structure compact and flexible. At the same time, when damage occurs, the inner and outer self-healing materials can work together to restore the shielding layer from exposure or damage.

[0045] Furthermore: In step S10, the extrusion temperature is 140~190℃ and the die head temperature is 170~190℃.

[0046] In step S30, the extrusion temperature is 130~210℃, the screw speed is 20~60rpm, and the traction speed is 10~40m / min.

[0047] Specifically, this embodiment optimizes the extrusion process parameters to address the thermoplastic processing characteristics of self-healing polyurethane elastomers: Step S10, with a temperature range of 140~190℃ (170~190℃ at the die head), ensures that the material is fully melted and has good fluidity, while avoiding excessively high temperatures that could lead to thermal degradation of disulfide or hydrogen bond networks, thus maintaining the activity of dynamic bonds and the material's self-healing ability.

[0048] Step S30 has a temperature range of 130~210℃, covering a wider range to accommodate different formulations. The screw speed is 20~60rpm to ensure moderate shearing and avoid excessive shearing that could damage the molecular network. The traction speed is 10~40m / min to ensure uniform cooling, smooth surface, and dimensional stability of the extrudate.

[0049] The above parameter range ensures the thermoplastic processing performance of the material while preserving the dynamic disulfide and hydrogen bond structure in the polyurethane network to the maximum extent, so that the insulation layer and outer sheath of the final cable maintain high self-healing efficiency and mechanical properties.

[0050] Furthermore, surface-functionalized silver-plated carbon fibers are also added to the second melt; the amount of surface-functionalized silver-plated carbon fibers added is 8 to 12 parts by weight.

[0051] Furthermore, surface-functionalized silver-plated carbon fibers are prepared through the following steps: S100. Surface activation treatment is performed on the carbon fiber.

[0052] S200. Chemical silver plating is performed on the surface-activated carbon fiber to obtain silver-plated carbon fiber.

[0053] S300. Surface functionalization treatment is performed on silver-plated carbon fiber to obtain surface functionalized silver-plated carbon fiber.

[0054] Specifically, this embodiment employs a three-step surface modification process to construct a highly conductive silver plating layer with excellent interfacial compatibility on the carbon fiber surface, and further functionalizes it to enhance shielding effectiveness without affecting the performance of the self-healing polyurethane matrix. Step S100 introduces active functional groups such as hydroxyl and carboxyl groups on the carbon fiber surface through chemical or physical methods (such as oxidation or plasma treatment), which significantly improves the surface polarity and chemical reactivity, providing a good adhesion basis for subsequent silver plating.

[0055] In step S200, sensitization, activation, and chemical reduction silver plating are sequentially performed on the activated surface, resulting in a uniform and dense silver layer deposited on the carbon fiber surface, forming a highly conductive network. The high conductivity of silver significantly improves the electromagnetic shielding effectiveness of the composite material.

[0056] In step S300, the silver layer is modified using silane coupling agents to introduce functional groups such as amino and epoxy groups onto the silver surface. These functional groups can form additional hydrogen bonds or chemical bonds with urea bonds and urethane bonds in the polyurethane matrix, enhancing the interfacial bonding force between the filler and the matrix, and enabling the silver-plated carbon fibers to be uniformly dispersed in the polyurethane matrix and form a stable conductive network.

[0057] Through the above three-step process, the surface-functionalized silver-plated carbon fiber has both high conductivity and good compatibility with the self-healing polyurethane matrix, ensuring that the addition does not damage the dynamic bond network and self-healing ability of the matrix.

[0058] Furthermore: In step S100, the surface activation treatment is selected from at least one of nitric acid oxidation treatment, plasma treatment, or ozone treatment.

[0059] In step S200, the chemical silver plating process includes sequential sensitization, activation, and chemical reduction silver plating processes.

[0060] In step S300, the surface functionalization treatment uses a silane coupling agent to modify the surface of the silver-plated carbon fiber. The silane coupling agent is selected from at least one of silane coupling agents containing amino or epoxy groups.

[0061] Furthermore, conductor 1 is formed by stranding or re-stranding multiple strands of tin-plated copper wire.

[0062] Furthermore, the shielding layer 3 includes a copper wire braided layer and an aluminum foil composite strip, wherein the braiding density of the copper wire braided layer is not less than 85%.

[0063] Specific embodiments are provided below. These embodiments are intended to enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way.

[0064] Example 1 Step 1: Preparation of self-healing polyurethane elastomer 1.00 kg of PTMG was added to a four-necked flask, and the mixture was heated to 80.5 °C under nitrogen protection. The mixture was stirred for 30 min to remove trace amounts of moisture. 600.0 g of IPDI was slowly added dropwise, with the temperature controlled to not exceed 82 °C during the addition. After the addition was complete, 0.35 g of DBTDL was added under nitrogen protection, and the mixture was heated to 81.2 °C. The reaction was allowed to proceed for 3 h 10 min to obtain the terminal-NCO prepolymer.

[0065] The temperature was lowered to 70.3℃, and 160.2 g of bis(2-hydroxyethyl) disulfide was added first. After stirring until homogeneous, 79.8 g of IPDA was added. After the addition was complete, the temperature was raised to 71.8℃, and the reaction was continued for 6 h 35 min.

[0066] At the end of the reaction, the viscosity of the system increased significantly. Stirring was stopped, and the system was degassed under vacuum for 30 minutes (vacuum degree -0.095MPa). The melt was poured into a polytetrafluoroethylene mold and allowed to cool naturally to room temperature, yielding a transparent, light yellow self-healing polyurethane elastomer with a smooth surface and no bubbles.

[0067] Step 2: Cable Sample Preparation It employs a small single-screw extruder (screw diameter 25 mm, L / D=25:1), a copper wire braiding machine, an aluminum foil winding machine, and a water-cooled traction machine.

[0068] The cable structure is as follows: Conductor: Class 6 multi-strand tinned copper wire (7×19×0.15 mm, twisted); Insulation layer: self-healing polyurethane, wall thickness 0.8 mm; Shielding layer: Copper wire braid (density 88%) + aluminum foil composite tape; Outer sheath: same insulation material, wall thickness 1.2 mm.

[0069] Extrusion process parameters: Insulation layer: feeding section 148℃, compression section 172℃, metering section 185℃, die head 188℃; Outer sheath: Feed section 142℃, compression section 168℃, metering section 182℃, die head 186℃; Screw speed: 35 rpm (insulation), 42 rpm (sheath); Traction speed: 18.5 m / min.

[0070] The extrusion process proceeded normally without material breakage or smoke, and the cable surface was smooth with stable dimensions.

[0071] Step 3: Sample Testing Self-healing performance Sample: Dumbbell-shaped specimens (GB / T 528-2009 Type A) cut from the outer sheath.

[0072] Damage: A straight scratch with a depth of 0.52 mm and a length of 10.1 mm was made with a scalpel.

[0073] Repair conditions: 25.2℃ constant temperature and humidity chamber (RH 50%), 48 h.

[0074] Test: Universal testing machine, tensile speed 500 mm / min, record the breaking strength.

[0075] Anti-kink properties Sample: 2 m long cable, fixed at both ends.

[0076] Method: Torsional fatigue testing machine, ±360° torsion, frequency 1 Hz, 10 cycles 6 Second-rate.

[0077] Judgment: Visually inspect for cracks, and test the continuity of the conductor by applying current.

[0078] Electromagnetic shielding effectiveness Method: Coaxial transmission line method (SJ / T 11223-2000), frequency 100 MHz–1 GHz.

[0079] Sample: 1 m cable.

[0080] The test data is shown in Table 1 below: Example 2 Step 1: Preparation of surface-functionalized silver-plated carbon fibers Take 100.0 g of carbon fiber and add it to 500 mL of concentrated nitric acid (68%). Stir and reflux at 80.5 °C for 4 h 20 min. After cooling, wash repeatedly with deionized water until neutral, and dry at 80 °C to obtain surface-activated carbon fiber.

[0081] Add the activated carbon fibers to 500 mL of deionized water, and then add the following in sequence: Sensitization solution: SnCl2·2H2O 5.2 g + HCl 2.0 mL, stir for 30 min; Activation solution: 0.15 g PdCl2 + 0.5 mL HCl, stir for 20 min; Reduced silver plating solution: AgNO3 18.5 g + NH3·H2O (25%) until clear, add formaldehyde (37%) 12.0 g, react at 60.8℃ for 45 min.

[0082] After the reaction was completed, the mixture was filtered, washed with deionized water and ethanol, and dried under vacuum at 80°C to obtain silver-plated carbon fiber.

[0083] Silver-plated carbon fibers were dispersed in 300 mL of ethanol / water (1:1) mixture, and 3.8 g of KH-550 was added. The mixture was stirred at 60.2 °C for 2 h 15 min. After filtration, the carbon fibers were washed three times with ethanol and dried at 100 °C for 2 h to obtain surface-functionalized silver-plated carbon fibers.

[0084] Step 2: Preparation of self-healing polyurethane elastomer 1.00 kg of PTMG was added to a four-necked flask, and the mixture was heated to 80.7 °C under nitrogen protection. The mixture was stirred for 30 min to remove trace amounts of moisture. 600.0 g of IPDI was slowly added dropwise, with the temperature controlled to not exceed 82 °C during the addition. After the addition was complete, 0.35 g of DBTDL was added under nitrogen protection, and the mixture was heated to 81.4 °C. The reaction was allowed to proceed for 3 h 05 min to obtain the terminal-NCO prepolymer.

[0085] The temperature was lowered to 70.5℃, and 160.2 g of bis(2-hydroxyethyl) disulfide was added first. After stirring until homogeneous, 79.8 g of IPDA was added. After the addition was complete, the temperature was raised to 71.9℃, and the reaction was continued for 6 h 40 min.

[0086] At the end of the reaction, the viscosity of the system increased significantly. Stirring was stopped, and the system was degassed under vacuum for 30 minutes (vacuum degree -0.094 MPa). The melt was poured into a polytetrafluoroethylene mold and allowed to cool naturally to room temperature to obtain a transparent, light yellow self-healing polyurethane elastomer.

[0087] Step 3: Cable Sample Preparation It employs a small single-screw extruder (screw diameter 25 mm, L / D=25:1), a copper wire braiding machine, an aluminum foil winding machine, and a water-cooled traction machine.

[0088] The cable structure is as follows: Conductor: Class 6 multi-strand tinned copper wire (7×19×0.15 mm, twisted); Insulation layer: self-healing polyurethane, wall thickness 0.8 mm; Shielding layer: Copper wire braid (density 88%) + aluminum foil composite tape; Outer sheath: self-healing polyurethane matrix + surface functionalized silver-plated carbon fiber, wall thickness 1.2 mm.

[0089] During the extrusion of the outer sheath, 102.6 g of surface-functionalized silver-plated carbon fiber was added to 1.84 kg of self-healing polyurethane melt and dispersed evenly by high-speed stirring (800 rpm) for 35 min.

[0090] Extrusion process parameters: Insulation layer: feeding section 148℃, compression section 172℃, metering section 185℃, die head 188℃; Outer sheath: Feed section 143℃, compression section 169℃, metering section 184℃, die head 187℃; Screw speed: 35 rpm (insulation), 43 rpm (sheath); Traction speed: 18.7 m / min.

[0091] The extrusion process proceeded normally without material breakage or smoke, and the cable surface was smooth with stable dimensions.

[0092] Step 4: Sample Testing The test items and methods are the same as in Example 1, and the test data are shown in Table 2 below: Example 3 Step 1: Preparation of self-healing polyurethane elastomer 1.00 kg of amino-terminated polydimethylsiloxane (aminoPDMS, Mn=2000) was added to a four-necked flask, and the mixture was heated to 90.3 °C under nitrogen protection and stirred for 35 min to remove trace amounts of moisture. 550.0 g of IPDI was slowly added dropwise, with the temperature controlled to not exceed 92 °C during the addition. After the addition was complete, 0.32 g of DBTDL was added under nitrogen protection, and the mixture was heated to 91.1 °C and reacted for 2 h 40 min to obtain a prepolymer containing NCO groups.

[0093] The temperature was lowered to 75.4℃, and 180.3 g of 2,2'-dithiodiethanol was added first. After stirring evenly, 100.1 g of diethylenetriamine (DETA) was added. After the addition was complete, the temperature was raised to 76.2℃, and the reaction was continued for 7 h 5 min.

[0094] At the end of the reaction, the viscosity of the system increased significantly. Stirring was stopped, and the system was degassed under vacuum for 30 minutes (vacuum degree -0.093 MPa). The melt was poured into a polytetrafluoroethylene mold and allowed to cool naturally to room temperature, yielding a transparent, light yellow self-healing polyurethane elastomer with a smooth surface and no bubbles.

[0095] Step 2: Cable Sample Preparation It employs a small single-screw extruder (screw diameter 25 mm, L / D=25:1), a copper wire braiding machine, an aluminum foil winding machine, and a water-cooled traction machine.

[0096] The cable structure is as follows: Conductor: Class 6 multi-strand tinned copper wire (7×19×0.15 mm, twisted); Insulation layer: self-healing polyurethane, wall thickness 0.8 mm; Shielding layer: Copper wire braid (density 88%) + aluminum foil composite tape; Outer sheath: same insulation material, wall thickness 1.2 mm.

[0097] Extrusion process parameters: Insulation layer: feeding section 138℃, compression section 162℃, metering section 175℃, die head 178℃; Outer sheath: Feed section 135℃, compression section 158℃, metering section 172℃, die head 175℃; Screw speed: 34 rpm (insulation), 41 rpm (sheath); Traction speed: 19.2 m / min.

[0098] The extrusion process proceeded normally without material breakage or smoke. The cable surface was smooth, the dimensions were stable, and the flexibility was excellent.

[0099] Step 3: Sample Testing The test items and methods are the same as in Example 1, and the test data are shown in Table 3 below: Example 4 Step 1: Preparation of surface-functionalized silver-plated carbon fibers Take 100.0 g of carbon fiber and add it to 500 mL of concentrated nitric acid (68%). Stir and reflux at 81.2℃ for 4 h 15 min. After cooling, wash repeatedly with deionized water until neutral, and dry at 80℃ to obtain surface-activated carbon fiber.

[0100] Add the activated carbon fibers to 500 mL of deionized water, and then add the following in sequence: Sensitization solution: SnCl2·2H2O 5.1 g + HCl 2.1 mL, stir for 30 min; Activation solution: 0.14 g PdCl2 + 0.6 mL HCl, stirred for 20 min; Reduced silver plating solution: AgNO3 18.2 g + NH3·H2O (25%) until clear, add formaldehyde (37%) 11.8 g, react at 61.0℃ for 48 min.

[0101] After the reaction was completed, the mixture was filtered, washed with deionized water and ethanol, and dried under vacuum at 80°C to obtain silver-plated carbon fiber.

[0102] Silver-plated carbon fibers were dispersed in 300 mL of ethanol / water (1:1) mixture, and 3.9 g of KH-560 was added. The mixture was stirred at 60.5 °C for 2 h 20 min. After filtration, the carbon fibers were washed three times with ethanol and dried at 100 °C for 2 h to obtain surface-functionalized silver-plated carbon fibers.

[0103] Step 2: Preparation of self-healing polyurethane elastomer 600.0 g of PTMG (Mn=2000) and 400.0 g of amino-terminated polydimethylsiloxane (aminoPDMS, Mn=2000) were added to a four-necked flask. Under nitrogen protection, the mixture was heated to 85.6 °C and stirred for 35 min to remove trace amounts of moisture. 580.0 g of IPDI was slowly added dropwise, with the temperature controlled to not exceed 87 °C during the addition. After the addition was complete, 0.34 g of DBTDL was added under nitrogen protection, and the mixture was heated to 86.3 °C and reacted for 3 h 00 min to obtain a prepolymer containing isocyanate groups.

[0104] The temperature was lowered to 70.8℃, and 170.4 g of 3,3'-dithiodipropanol was added first. After stirring until homogeneous, 90.2 g of 4,4'-diaminodicyclohexylmethane (PACM) was added. After the addition was complete, the temperature was raised to 71.5℃, and the reaction was continued for 6 h 45 min.

[0105] At the end of the reaction, the viscosity of the system increased significantly. Stirring was stopped, and the system was degassed under vacuum for 30 minutes (vacuum degree -0.094 MPa). The melt was poured into a polytetrafluoroethylene mold and allowed to cool naturally to room temperature to obtain a transparent, light yellow self-healing polyurethane elastomer.

[0106] Step 3: Cable Sample Preparation It employs a small single-screw extruder (screw diameter 25 mm, L / D=25:1), a copper wire braiding machine, an aluminum foil winding machine, and a water-cooled traction machine.

[0107] The cable structure is as follows: Conductor: Class 6 multi-strand tinned copper wire (7×19×0.15 mm, twisted); Insulation layer: self-healing polyurethane, wall thickness 0.8 mm; Shielding layer: Copper wire braid (density 88%) + aluminum foil composite tape; Outer sheath: self-healing polyurethane matrix + surface functionalized silver-plated carbon fiber, wall thickness 1.2 mm.

[0108] During the extrusion of the outer sheath, 103.1 g of surface-functionalized silver-plated carbon fiber was added to 1.84 kg of self-healing polyurethane melt and dispersed evenly by high-speed stirring (800 rpm) for 35 min.

[0109] Extrusion process parameters: Insulation layer: feeding section 145℃, compression section 170℃, metering section 183℃, die head 186℃; Outer sheath: Feeding section 140℃, compression section 166℃, metering section 180℃, die head 184℃; Screw speed: 36 rpm (insulation), 44 rpm (sheath); Traction speed: 18.9 m / min.

[0110] The extrusion process proceeded normally without material breakage or smoke. The cable surface was smooth, the dimensions were stable, and the flexibility was excellent.

[0111] Step 4: Sample Testing The test items and methods are the same as in Example 1, and the test data are shown in Table 4 below: Comparative Example 1 Step 1: Material Preparation Commercially available high-elasticity thermoplastic polyurethane (TPU) particles are used directly as the insulation layer and outer sheath material.

[0112] Additives: 10 g of antioxidant Irganox 1010 and 20 g of lubricant calcium stearate.

[0113] Step 2: Cable Sample Preparation It employs a small single-screw extruder (screw diameter 25 mm, L / D=25:1), a copper wire braiding machine, an aluminum foil winding machine, and a water-cooled traction machine.

[0114] The cable structure is as follows: Conductor: Class 6 multi-strand tinned copper wire (7×19×0.15 mm, twisted); Insulation layer: TPU, wall thickness 0.8 mm; Shielding layer: Copper wire braid (density 88%) + aluminum foil composite tape; Outer sheath: TPU, wall thickness 1.2 mm.

[0115] Extrusion process parameters: Insulation layer: 150℃ for feeding section, 175℃ for compression section, 190℃ for metering section, and 192℃ for die head; Outer sheath: Feed section 148℃, compression section 172℃, metering section 188℃, die head 190℃; Screw speed: 36 rpm (insulation), 43 rpm (sheath); Traction speed: 19.0 m / min.

[0116] The extrusion process proceeded normally without material breakage or smoke, and the cable surface was smooth with stable dimensions.

[0117] Step 3: Sample Testing The test items and methods are the same as in Example 1, and the test data are shown in Table 5 below: The data above show that the tensile strength recovery rate of Examples 1-4 after 48 hours of repair at room temperature is 92.5%-93.2%, and the elongation at break recovery rate is also above 93%, indicating that the self-healing polyurethane network based on the synergy of dynamic disulfide bonds and multi-strength hydrogen bonds has a highly efficient room temperature self-healing capability. The self-healing efficiency of this embodiment is far higher than that of the prior art, solving the problem of manual replacement after damage in the background art.

[0118] Examples 1 and 2 in 10 6 No cracks were found after ±360° torsion cycles; this indicates that the dynamic bond energy dissipation mechanism combined with the highly flexible soft segment enables the cable to exhibit excellent fatigue resistance in high-frequency torsion and bending environments, far exceeding that of traditional TPU cables.

[0119] Examples 1 and 3 show an initial shielding effectiveness of approximately 34–35 dB, primarily relying on a copper wire braided shielding layer combined with an aluminum foil shielding layer. Examples 2 and 4, with the addition of surface-functionalized silver-plated carbon fiber, show an initial shielding effectiveness of 42.6–44.1 dB, meeting the requirements for high-performance shielding.

[0120] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be within the scope of protection of the present invention.

Claims

1. A self-healing, anti-kink shielded composite cable, characterized in that, The product comprises, from the inside out, a conductor (1), an insulating layer (2), a shielding layer (3), and an outer sheath (4), wherein the insulating layer (2) and / or the outer sheath (4) are obtained by extrusion of a self-healing polyurethane elastomer; the self-healing polyurethane elastomer is made of the following components by weight: 100 parts of soft segment polyol, 40-80 parts of isophorone diisocyanate, 12-20 parts of chain extender containing disulfide bonds, and 5-12 parts of chain extender containing urea groups, wherein the soft segment polyol is selected from at least one of polytetrahydrofuran ether diol and amino-terminated polydimethylsiloxane.

2. The self-healing anti-kink shielded composite cable according to claim 1, characterized in that: The disulfide-containing chain extender is selected from at least one of bis(2-hydroxyethyl) disulfide, 2,2'-dithiodiethanol, and 3,3'-dithiodipropanol; The urea-containing chain extender is selected from at least one of diethylenetriamine, isophorone diamine, and 4,4'-diaminodicyclohexylmethane.

3. The self-healing anti-kink shielded composite cable according to claim 1, characterized in that, The self-healing polyurethane elastomer is prepared through the following steps: S1. Soft segment polyol and isophorone diisocyanate are reacted at 70~100℃ for 2~4 hours under inert gas protection to obtain a prepolymer with terminal isocyanate groups; S2. Add a chain extender containing disulfide bonds and a chain extender containing urea groups to the prepolymer, and continue the reaction at 60~80°C for 4~10 hours to obtain the self-healing polyurethane elastomer.

4. The self-healing anti-kink shielded composite cable according to any one of claims 1 to 3, characterized in that, The self-healing anti-kink shielded composite cable is prepared through the following steps: S10. After melting the self-healing polyurethane elastomer, a first melt is formed. The first melt is extruded and coated on the outer surface of the conductor (1) to form an insulating layer (2). S20. Copper wire braid and aluminum foil composite tape are sequentially applied to the outer surface of the insulating layer (2) to form a shielding layer (3); S30. After melting the self-healing polyurethane elastomer, a second melt is formed. The second melt is extruded and coated on the outer surface of the shielding layer (3) to form an outer sheath (4).

5. The self-healing anti-kink shielded composite cable according to claim 4, characterized in that: In step S10, the extrusion temperature is 140~190℃ and the die head temperature is 170~190℃; In step S30, the extrusion temperature is 130~210℃, the screw speed is 20~60rpm, and the traction speed is 10~40m / min.

6. The self-healing anti-kink shielded composite cable according to claim 4, characterized in that, The second melt also contains surface-functionalized silver-plated carbon fibers.

7. The self-healing anti-kink shielded composite cable according to claim 6, characterized in that, The surface-functionalized silver-plated carbon fiber is prepared by the following steps: S100. Surface activation treatment is applied to the carbon fiber; S200. Chemical silver plating is performed on the surface-activated carbon fiber to obtain silver-plated carbon fiber; S300. The silver-plated carbon fiber is subjected to surface functionalization treatment to obtain surface-functionalized silver-plated carbon fiber.

8. The self-healing anti-kink shielded composite cable according to claim 7, characterized in that: In step S100, the surface activation treatment is selected from at least one of nitric acid oxidation treatment, plasma treatment, or ozone treatment; In step S200, the chemical silver plating includes sequential sensitization, activation, and chemical reduction silver plating processes; In step S300, the surface functionalization treatment uses a silane coupling agent to modify the surface of silver-plated carbon fibers. The silane coupling agent is selected from at least one of silane coupling agents containing amino or epoxy groups.

9. The self-healing anti-kink shielded composite cable according to any one of claims 1 to 3, characterized in that, The conductor (1) is formed by stranding or re-stranding multiple strands of tin-plated copper wire.

10. The self-healing anti-kink shielded composite cable according to any one of claims 1 to 3, characterized in that, The shielding layer (3) includes a copper wire braided layer and an aluminum foil composite strip, wherein the braiding density of the copper wire braided layer is not less than 85%.

Images