A highly tear resistant cable material and method of manufacture

Abstract

The present application relates to the technical field of cable material, in particular to a kind of high tear-resistant cable material and preparation method.The material takes hydrogenated styrene-butadiene-styrene block copolymer as matrix, contains carboxyl-terminated liquid fluororubber microcapsule and polypyrrole modified layered double hydroxide nanosheet.Through the process of containing dynamic vulcanization, the microcapsule core material is released and interfacial interaction occurs with nanosheet, and dynamic sacrificial network and rigid nanoskeleton interpenetrating structure are constructed in situ in matrix.The material has both ultra-high tear strength (≥78kN / m) and high elongation at break (≥400%), and realizes early mechanical damage electrical warning function using sensitive conductive network formed by polypyrrole on the surface of nanosheet.Meanwhile, the material maintains excellent flame retardancy, insulation, heat resistance and processing performance, and is suitable for cable sheath with high requirements for reliability and intelligentization.

Description

Technical Field

[0001] This invention relates to the field of cable material technology, and more specifically, to a high tear-resistant cable material and its preparation method. Background Technology

[0002] As a crucial barrier protecting the internal conductors, the mechanical properties of the cable sheath, especially its tear resistance, directly determine the cable's service life and safety under complex operating conditions (such as dragging, bending, and impact). Extremely high requirements for the tear resistance of cable sheaths are placed in fields such as robot joints, marine engineering, mining equipment, and smart grids.

[0003] Currently, the mainstream technical approach to improving the tear resistance of cable sheaths involves adding reinforcing phases to the polymer matrix (such as polyvinyl chloride, polyethylene, and rubber). Common reinforcing phases include chopped fibers (such as aramid and glass fibers) and rigid nanoparticles (such as nano-calcium carbonate and silica). However, these methods have significant limitations: while fiber reinforcement can improve strength, it often comes at the cost of material flexibility and processing fluidity, and the physical interface between the fiber and the matrix is ​​prone to debonding under long-term dynamic stress, leading to performance degradation; adding nanoparticles faces challenges such as difficulty in dispersion and easy agglomeration, resulting in limited improvement in tear strength (usually only 20%-50%), and may also impair the insulation properties of the material.

[0004] More importantly, the aforementioned methods all represent passive performance enhancement, with a single enhancement mechanism (such as fiber pull-out or particle-induced crack blockage), failing to achieve a synergistic performance leap. Furthermore, existing sheath materials completely lack active sensing capabilities. When internal microcracks develop in the material due to fatigue or external damage, no warning is provided until the cracks propagate and cause insulation failure, potentially leading to serious electrical accidents. Summary of the Invention

[0005] The purpose of this invention is to provide a high tear-resistant cable material and its preparation method to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, on the one hand, the present invention provides a high tear-resistant cable material, the core of which comprises two components: end-carboxyl liquid fluororubber microcapsules as a dynamic sacrificial network and polypyrrole-modified layered double metal hydroxide (PPy@LDH) nanosheets as a rigid nanoskeleton. The raw materials, by weight, include:

[0007] Polymer matrix: 40-60 parts of hydrogenated styrene-butadiene-styrene block copolymer (SEBS), whose saturated structure provides excellent flexibility, insulation and weather resistance.

[0008] Dynamic sacrificial network component: 15-25 parts of terminal carboxyl-terminated liquid fluororubber microcapsules, wherein the wall material of the microcapsules is thermoplastic polyurethane (TPU) and the core material is vinylidene fluoride liquid fluororubber with active carboxyl groups.

[0009] Rigid nanoframework component: 5-12 parts of polypyrrole-modified layered bimetallic hydroxide (PPy@LDH) nanosheets, with a conductive polypyrrole (PPy) layer coated on the surface of the LDH nanosheets by in-situ polymerization.

[0010] Flame retardant synergist: 8-15 parts aluminum hypophosphate coated zinc borate (AHP@ZB).

[0011] Processing aids and stabilizers: 2-4 parts ethylene-vinyl acetate copolymer (EVA), 0.5-1.5 parts antioxidant and light stabilizer compound.

[0012] Crosslinking agent: 0.5-2 parts dicumyl peroxide (DCP), used to prepare crosslinked materials.

[0013] In this invention, during the dynamic vulcanization stage of the preparation process, the TPU wall material of the carboxyl-terminated liquid fluororubber microcapsules melts, releasing the core material and releasing liquid fluororubber. The active carboxyl groups (-COOH) at the ends react with metal ions (such as Mg) on ​​the surface of the PPy@LDH nanosheets. 2+ Al 3+ This generates strong ion-dipole interactions and interfacial bonds. These interfacial chemical bonds act like flexible bridges, connecting countless rigid nano-islands (PPy@LDH) to form a three-dimensional, rigid-flexible interpenetrating network structure in the SEBS matrix, namely a dynamic sacrificial network and rigid nanoskeleton system.

[0014] Specifically: When a material is subjected to tearing stress, the crack tip first encounters a rigid barrier composed of PPy@LDH nanosheets. In order to overcome these high-modulus barriers, the crack needs to consume a huge amount of energy to deflect it or cause the nanosheets to be pulled out. At this time, the flexible bridge of liquid fluororubber connecting the nanosheets becomes the core energy dissipation region. It efficiently absorbs and dissipates energy through the intense stretching, slippage, plastic deformation, and even the breaking of some chemical bonds of its molecular chains. PPy@LDH provides the strength and density to hinder crack propagation, while liquid fluororubber provides an extremely efficient energy dissipation pathway in the process of overcoming the barrier.

[0015] The conductive polypyrrole layer on the surface of PPy@LDH nanosheets forms a micro-conductive permeation network inside the material. When the material is intact, the network connectivity is stable and the whole remains highly insulating. Once microcracks initiate inside, causing the liquid fluororubber bridge to break or the PPy@LDH nanosheets to shift, the connectivity of the conductive network is disrupted, causing a step increase in the material resistance, thus achieving an electrical early warning of early mechanical damage.

[0016] AHP@ZB, PPy@LDH (decomposition endothermic, catalytic char formation), and liquid fluororubber (fluorine element captures free radicals) produce synergistic flame retardancy. The SEBS matrix and good interfacial bonding ensure the material's flexibility, high insulation, and processability.

[0017] On the other hand, the present invention provides a method for preparing the above-mentioned high tear-resistant cable material, comprising the following steps:

[0018] S1. Preparation of polypyrrole-modified layered double metal hydroxide (PPy@LDH) nanosheets:

[0019] Layered bimetallic hydroxide (LDH) nanosheets were uniformly dispersed in water, and pyrrole monomers were added. An in-situ polymerization reaction was carried out under the action of an oxidant to coat the surface of the LDH nanosheets with polypyrrole (PPy). After the reaction was completed, the nanosheets were washed and dried to obtain PPy@LDH nanosheets.

[0020] S2. Preparation of carboxyl-terminated liquid fluororubber microcapsules:

[0021] Using interfacial polymerization, core-shell microcapsules were formed with vinylidene fluoride liquid fluororubber containing active carboxyl groups as the core material and thermoplastic polyurethane (TPU) prepolymer as the wall material under emulsification and polymerization conditions. After separation and drying, carboxyl-terminated liquid fluororubber microcapsules were obtained.

[0022] S3, Premixed:

[0023] Hydrogenated styrene-butadiene-styrene block copolymer (SEBS) and ethylene-vinyl acetate copolymer (EVA) are added to a mixer and plasticized at 120-140°C. Then, aluminum hypophosphite-coated zinc borate (AHP@ZB), stabilizers, and PPy@LDH nanosheets prepared by S1 are added, and the mixture is continued to be mixed for 5-10 minutes until it is evenly dispersed to obtain a premix.

[0024] S4. Dynamic vulcanization and collaborative network construction:

[0025] The temperature of the premixed material is raised to 160-170℃, and the carboxyl-terminated liquid fluororubber microcapsules prepared by S2 and the crosslinking agent dicumyl peroxide (DCP) are added. The mixture is then melt-blended and dynamically vulcanized under shear force for 3-8 minutes. During this process, the wall material of the carboxyl-terminated liquid fluororubber microcapsules melts and the core material is released. The carboxyl groups of the microcapsules interact with the surface of the PPy@LDH nanosheets through interfacial chemical reactions, while initiating partial crosslinking in the SEBS matrix, thereby forming an in-situ interpenetrating structure of "dynamic sacrificial network-rigid nanoskeleton".

[0026] S5. Granulation:

[0027] The dynamically vulcanized material is transferred to a twin-screw extruder, where it is extruded, cooled, pelletized, and dried at a processing temperature of 150-160℃ to obtain the high tear-resistant and flame-retardant cable sheath material granules with self-monitoring function.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] In this high tear-resistant cable material and its preparation method, based on the dynamic sacrificial network-rigid nanoskeleton mechanism, the tear strength of the material can reach more than 80kN / m, far exceeding that of traditional fiber or nanoparticle reinforced materials (usually 20-50kN / m), achieving a qualitative leap in tear resistance while maintaining a high elongation at break (>400%).

[0030] Without adding high-content conductive fillers that impair insulation, the structure sensitivity of the internal conductive network is cleverly utilized to endow the material with early warning capabilities for mechanical damage, providing an innovative solution for condition monitoring and preventive maintenance of smart cables.

[0031] The material achieves ultra-high tear resistance while also possessing excellent flame retardancy (limiting oxygen index LOI ≥ 32%) and high insulation (volume resistivity ≥ 1 × 10⁻⁶). 15 With its excellent Ω·m, good weather resistance, chemical resistance, and superior extrusion processing performance, it breaks through the dilemma of mutual constraints on performance in traditional technologies. Attached Figure Description

[0032] Figure 1 This is an overall flowchart of Embodiment 1 of the present invention. Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1: This embodiment of the invention provides a high tear-resistant cable material, the raw material composition of which is as follows by weight:

[0035] Hydrogenated styrene-butadiene-styrene block copolymer (SEBS): 55 parts;

[0036] Carboxyl-terminated liquid fluororubber microcapsules: 18 parts;

[0037] Polypyrrole-modified layered bimetallic hydroxide (PPy@LDH) nanosheets: 6 parts;

[0038] Aluminum hypophosphite coated zinc borate (AHP@ZB): 10 parts;

[0039] Ethylene-vinyl acetate copolymer (EVA): 3 parts;

[0040] Antioxidant and light stabilizer compound (1010 and 770 in a 1:1 ratio): 1 part;

[0041] Dicumyl peroxide (DCP): 0.8 parts.

[0042] according to Figure 1 As shown, its preparation method includes the following steps:

[0043] (1) Preparation of PPy@LDH nanosheets:

[0044] 5g of magnesium aluminum hydrotalcite (Mg:Al=3:1) nanosheets were dispersed in 200mL of deionized water and sonicated for 30min. 1.5g of pyrrole monomer was added and stirred in an ice-water bath (0-5℃). 3g of ammonium persulfate was dissolved in 50mL of water and added slowly. The reaction was carried out for 12h. The product was filtered, washed, dried under vacuum at 60℃ for 24h, and ground for later use.

[0045] (2) Preparation of carboxyl-terminated liquid fluororubber microcapsules:

[0046] 10g of vinylidene fluoride liquid fluororubber with active carboxyl groups and 5g of thermoplastic polyurethane prepolymer were dissolved in 40g of dichloromethane as the oil phase, and 2g of polyvinyl alcohol was dissolved in 200g of water as the aqueous phase. The oil phase was added dropwise to the aqueous phase under high-speed shear (10000rpm), and emulsification was carried out for 15min. The mixture was transferred to a reactor at 45℃, and 0.5g of ethylenediamine aqueous solution was added. The reaction was carried out for 4h. The product was cooled, filtered, washed, and vacuum dried at 40℃ for 24h to obtain microcapsules.

[0047] (3) Premixing:

[0048] SEBS and EVA were put into a mixer and plasticized at 130°C and 60 rpm for 2 minutes. AHP@ZB, antioxidant / light stabilizer compound and all PPy@LDH nanosheets prepared in step (1) were added. The speed was increased to 80 rpm and mixed for 8 minutes to obtain a premix.

[0049] (4) Dynamic vulcanization and network construction:

[0050] Raise the temperature of the internal mixer to 165°C, add all the carboxyl-terminated liquid fluororubber microcapsules and DCP prepared in step (2) to the premix, quickly increase the rotation speed to 100 rpm, react at 165°C for 5 minutes, and carry out dynamic vulcanization and interfacial bonding.

[0051] (5) Granulation and molding:

[0052] The above materials are transferred to a twin-screw extruder, melt-extruded at 155-160℃, cooled, pelletized, and dried at 80℃ for 4 hours to obtain cable material granules. The granules are then hot-pressed at 160℃ and 10MPa for 10 minutes to prepare standard test samples.

[0053] Example 2: The raw material composition, by weight, is as follows:

[0054] Hydrogenated styrene-butadiene-styrene block copolymer (SEBS): 50 parts;

[0055] Carboxyl-terminated liquid fluororubber microcapsules: 22 parts;

[0056] Polypyrrole-modified layered bimetallic hydroxide (PPy@LDH) nanosheets: 10 parts;

[0057] Aluminum hypophosphite coated zinc borate (AHP@ZB): 13 parts;

[0058] Ethylene-vinyl acetate copolymer (EVA): 3 parts;

[0059] Antioxidant and light stabilizer compound: 1 part;

[0060] Dicumyl peroxide (DCP): 1.2 parts.

[0061] Its preparation method is the same as steps (1)-(5) of Example 1, except that the raw materials are weighed and fed according to the above ratio.

[0062] Example 3

[0063] A high tear-resistant cable material, by weight, has the following raw material composition:

[0064] Hydrogenated styrene-butadiene-styrene block copolymer (SEBS): 45 parts;

[0065] Carboxyl-terminated liquid fluororubber microcapsules: 25 parts;

[0066] Polypyrrole-modified layered bimetallic hydroxide (PPy@LDH) nanosheets: 12 parts;

[0067] Aluminum hypophosphite coated zinc borate (AHP@ZB): 15 parts;

[0068] Ethylene-vinyl acetate copolymer (EVA): 4 parts;

[0069] Antioxidant and light stabilizer compound: 1.5 parts;

[0070] Dicumyl peroxide (DCP): 1.5 parts.

[0071] Its preparation method is the same as steps (1)-(5) of Example 1, except that the raw materials are weighed and fed according to the above ratio.

[0072] Comparative Example 1: Traditional Fiber Reinforcement

[0073] Its raw material composition is basically the same as that of Example 1, except that: instead of adding end-carboxyl liquid fluororubber microcapsules and PPy@LDH nanosheets, 8 parts of short-cut aramid fibers (3 mm in length) are added.

[0074] In the preparation method, aramid fibers are added to the internal mixer along with AHP@ZB and other materials in the premixing step (3). There is no subsequent dynamic vulcanization step, and the material directly enters the granulation step (5).

[0075] Comparative Example 2: Contains only microcapsules (single reinforcing phase)

[0076] Its raw material composition is basically the same as that of Example 1, except that PPy@LDH nanosheets are not added, and the amount of carboxyl-terminated liquid fluororubber microcapsules added is kept at 18 parts.

[0077] The preparation method is the same as in Example 1, but PPy@LDH nanosheets are not added during premixing in step (3), and only microcapsule release and partial crosslinking with the SEBS matrix occur during dynamic vulcanization in step (4).

[0078] Comparative Example 3: Contains only nanosheets (single reinforcing phase)

[0079] Its raw material composition is basically the same as that of Example 1, except that: no terminal carboxyl group liquid fluororubber microcapsules are added, and the amount of PPy@LDH nanosheets added is kept at 6 parts.

[0080] The preparation method is the same as in Example 1, but no carboxyl-terminated liquid fluororubber microcapsules are added during dynamic vulcanization in step (4).

[0081] Comparative Example 4: Unmodified LDH

[0082] Its raw material composition is basically the same as that of Example 1, except that: an equal amount of unmodified raw magnesium aluminum hydrotalcite (LDH) nanosheets are used instead of PPy@LDH nanosheets, and the amount of carboxyl-terminated liquid fluororubber microcapsules added is 18 parts.

[0083] The preparation method is the same as in Example 1.

[0084] Experimental Example: To verify the technical effects of the present invention, the materials prepared in the above embodiments and comparative examples were subjected to system performance tests.

[0085] The test methods for each item are as follows. All tests are conducted in a standard environment with a temperature of (23±2)℃ and a relative humidity of (50±5)%, and the samples are conditioned for at least 24 hours.

[0086] (1) Tear strength test

[0087] Test standard: GB / T 529-2008 Determination of tear strength of vulcanized rubber or thermoplastic rubber.

[0088] Sample specifications: Right-angled sample (without cut) with a thickness of (2.0±0.2) mm.

[0089] Testing equipment: Electronic tensile testing machine.

[0090] Test conditions: Tensile speed of 500 mm / min, record the maximum force value during the tearing process of the sample.

[0091] Result Calculation: Tear Strength According to the formula Calculation, where This represents the maximum force (in N) during the tearing process of the specimen. The thickness of the sample is in mm. The tear strength (in kN / m) is the arithmetic mean of five samples, and the result is in kN / m.

[0092] (2) Elongation at break test

[0093] Test standard: GB / T 1040.2-2006 "Determination of tensile properties of plastics - Part 2: Test conditions for molded and extruded plastics"

[0094] Sample specifications: Type 1A dumbbell-shaped sample, gauge length 25 mm, thickness (2.0±0.2) mm.

[0095] Testing equipment: Electronic tensile testing machine.

[0096] Test conditions: Tensile speed 50 mm / min. Record the distance between the marks when the specimen breaks.

[0097] Calculation of results: Elongation at break According to the formula Calculation, where The original gauge length of the sample is 25 mm. The distance between gauge marks (mm) when the specimen breaks. Elongation at break is expressed as a percentage (%), and the result is the arithmetic mean of 5 specimens.

[0098] (3) Limiting Oxygen Index (LOI) Test

[0099] Test Standard: GB / T 2406.2-2009 "Determination of Combustion Behavior of Plastics by Oxygen Index Method - Part 2: Room Temperature Test"

[0100] Sample specifications: a strip with a length of (80-150) mm, a width of (10±0.5) mm, and a thickness of (4.0±0.5) mm.

[0101] Testing equipment: Oxygen index meter.

[0102] Test procedure: The sample is vertically fixed in the combustion chamber, the flow rate of the nitrogen-oxygen mixture is adjusted, and the sample is ignited using the top ignition method. The minimum oxygen concentration that can be extinguished before the continuous combustion time exceeds 180 seconds or the combustion length exceeds 50 mm is determined by the lifting method.

[0103] Result: The oxygen index value (%) was read and recorded directly.

[0104] (4) Volume resistivity test

[0105] Test standard: GB / T 1410-2006 "Test methods for volume resistivity and surface resistivity of solid insulating materials"

[0106] Sample specifications: square sheet with a diameter of 100mm or a side length of 100mm and a thickness of (2.0±0.2)mm.

[0107] Test equipment: High resistance meter (equipped with a three-electrode system).

[0108] Test conditions: Apply a test voltage of 500V DC, and take the reading after 60s of electrolysis.

[0109] Calculation results: Volume resistivity According to the formula Calculation, where The measured volume resistivity (Ω) is given. The effective area (m²) of the measuring electrode 2 ), The average thickness of the sample is (m). Volume resistivity (unit: Ω·cm).

[0110] (5) Damage warning sensitivity (resistance change rate) test

[0111] Test objective: To simulate the changes in the internal conductive network of a material when it is subjected to external force and develops initial microcracks, in order to evaluate its self-monitoring capability.

[0112] Sample preparation: The material is molded into a standard 1A dumbbell-shaped sample (same as the elongation at break sample). The parallel parts at both ends of the sample are coated with conductive silver paste and copper foil electrodes are fixed to ensure good contact.

[0113] Testing equipment: Electronic tensile testing machine (equipped with displacement control), digital multimeter (high precision, used for measuring resistance).

[0114] Test program:

[0115] Mount the specimen with the electrodes installed on the tensile testing machine, and connect the electrodes to a multimeter. Apply a very small pretension (approximately 0.1 N) to straighten the specimen, and record the initial resistance value at this point. Start the tensile testing machine and stretch the specimen at a very slow, constant displacement rate (0.5 mm / min). When the gauge length elongation of the specimen displayed on the tensile testing machine reaches 2.0% (this strain level is designed to simulate the state of micro-damage initiation within the material but before macroscopic failure), immediately stop the stretching. Hold the specimen in this tensile state, stabilize for 10 seconds, and then record the resistance value at this point.

[0116] Result calculation: Rate of change of resistance According to the formula calculate. The initial resistance value of the specimen before stretching (in Ω). The resistance value (in Ω) is measured when the specimen is stretched to 2.0% of the gauge length elongation. The resistance change rate is expressed as a percentage (%). The larger the value, the more sensitive the material is to initial strain / damage. The result is the arithmetic mean of three samples.

[0117] (6) Thermal elongation test

[0118] Test Standard: GB / T 2951.21-2008 "General Test Methods for Insulation and Sheath Materials of Cables and Optical Fibers - Part 21: Test Methods for Elastomer Compounds - Ozone Resistance Test - Thermal Tensile Strength Test and Mineral Oil Immersion Test"

[0119] Sample specifications: dumbbell-shaped specimen with a gauge length of 20 mm and a thickness of (2.0 ± 0.2) mm.

[0120] Test equipment: Thermal stretching test apparatus (oven, weights, ruler).

[0121] Test conditions: Place the sample in an oven at (200±3)℃, apply a load of 0.20MPa to the lower end of the sample (calculate the specific weight of the weight based on the cross-sectional area of ​​the sample), and maintain the temperature for 15 minutes.

[0122] Result calculation: Rapidly measure the gauge length of the specimen under load. Thermal elongation is calculated using the formula calculate, 20 represents the gauge length of the specimen under load (in mm), and 20 represents the original gauge length of the specimen (in mm). The result is the arithmetic mean of three specimens.

[0123] Based on the above testing methods, the materials obtained in Examples 1-3 and Comparative Examples 1-4 were tested, and the specific results are summarized in Table 1 below.

[0124] Table 1: Summary of Performance Test Results

[0125] Test Project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Tear strength (kN / m) 78 88 92 41 48 35 52 Elongation at break (%) 450 420 400 250 490 420 430 Limiting Oxygen Index (LOI) (%) 31.5 33.0 34.5 25.5 28.0 29.5 30.0 Volume resistivity (Ω·cm) <![CDATA[5.0×10 14 ]]> <![CDATA[8.0×10 13 ]]> <![CDATA[2.0×10 13 ]]> <![CDATA[1.0×10 15 ]]> <![CDATA[9.0×10 14 ]]> <![CDATA[3.0×10 13 ]]> <![CDATA[1.2×10 15 ]]> <![CDATA[Damage warning sensitivity (ΔR / R0)]]> 850% 1200% 1500% ＜1% ＜5% 150% 30% Thermal elongation (%) 25 20 18 65 40 55 38

[0126] As shown in the table, the test results indicate that the tear strength (78-92 kN / m) of Examples 1-3 is significantly higher than all comparisons. Compared with Comparative Example 1 (conventional aramid fiber reinforcement), the present invention achieves more than double the tear strength under similar or better flexibility. In particular, compared with Comparative Example 2 (microcapsules only) and Comparative Example 3 (nanosheets only), which contain only a single reinforcing phase, the tear strength of the present invention far exceeds both, and even exceeds the sum of the two. This strongly demonstrates the synergistic effect of rigidity and flexibility and the performance multiplication effect brought about by the dynamic sacrificial network and rigid nanoskeleton interpenetrating structure formed by dynamic vulcanization between CTBN-VDF microcapsules and PPy@LDH nanosheets.

[0127] Secondly, Examples 1-3 exhibit extremely high damage warning sensitivity ( The sensitivity of the novel damage warning system is 850%-1500%, far exceeding that of other comparative examples. Comparative example 2 (without PPy@LDH) has almost no warning capability, comparative example 3 (without microcapsules) has very low sensitivity, and comparative example 4 (using ordinary LDH) also has extremely low sensitivity. This indicates that the damage warning function in this invention relies on the initial conductive network composed of polypyrrole-modified LDH nanosheets and the dramatic change in connectivity of this network when the flexible bridge of the terminal carboxyl-terminated liquid fluororubber breaks. Both are indispensable and together constitute a unique self-monitoring mechanism.

[0128] Meanwhile, Examples 1-3, while achieving ultra-high tear strength and intelligent early warning function, still maintain excellent flame retardancy (LOI>30%), good heat deformation resistance (low thermal elongation), and volume resistivity that meets the insulation requirements of most cables. In contrast, Comparative Example 1 exhibits poor flexibility, and Comparative Example 4, although possessing good insulation, has mediocre overall performance. In summary, this invention successfully achieves optimization and balance of multiple properties, including high strength, high elasticity, flame retardancy, heat resistance, and intelligent sensing.

[0129] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high tear-resistant cable material, characterized in that, By weight, its raw materials include: 40-60 parts of hydrogenated styrene-butadiene-styrene block copolymer; 15-25 parts of carboxyl-terminated liquid fluororubber microcapsules, wherein the wall material of the microcapsules is thermoplastic polyurethane and the core material is carboxyl-terminated liquid fluororubber; 5-12 parts of polypyrrole-modified layered bimetallic hydroxide nanosheets; 8-15 parts of flame retardant synergist; Processing aids 2-4 parts; Stabilizer 0.5-1.5 parts; Crosslinking agent 0.5-2 parts; In this process, polypyrrole is formed on the surface of layered bimetallic hydroxide nanosheets through in-situ polymerization; the material is prepared by a process including dynamic vulcanization, during which the core material of the carboxyl-terminated liquid fluororubber microcapsules is released and interacts with the polypyrrole-modified layered bimetallic hydroxide nanosheets, forming a network structure in the hydrogenated styrene-butadiene-styrene block copolymer matrix through which a dynamic sacrificial network and a rigid nanoskeleton interpenetrate.

2. The high tear-resistant cable material according to claim 1, characterized in that, The flame retardant synergist is aluminum hypophosphite coated with zinc borate; the processing aid is ethylene-vinyl acetate copolymer; the stabilizer includes a compound of antioxidant and light stabilizer; and the crosslinking agent is dicumyl peroxide.

3. The high tear-resistant cable material according to claim 2, characterized in that, The raw material composition, by weight, is as follows: 55 parts of hydrogenated styrene-butadiene-styrene block copolymer; 18 portions of carboxyl-terminated liquid fluororubber microcapsules; Six portions of polypyrrole-modified layered bimetallic hydroxide nanosheets; 10 parts of zinc borate coated with aluminum hypophosphite; 3 parts of ethylene-vinyl acetate copolymer; One part of the antioxidant and light stabilizer compound; 0.8 parts of dicumyl peroxide.

4. The high tear-resistant cable material according to claim 1, characterized in that, When subjected to tearing stress, the material has a tear strength of not less than 78 kN / m and an elongation at break of not less than 400%.

5. The high tear-resistant cable material according to claim 1, characterized in that, The material has a damage warning function. When the gauge length elongation of the material reaches 2%, its resistance change rate is not less than 850%.

6. A method for preparing the high tear-resistant cable material according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Disperse layered bimetallic hydroxide nanosheets in water, add pyrrole monomer and oxidant to carry out in-situ polymerization reaction, and after the reaction is completed, wash and dry to obtain polypyrrole-modified layered bimetallic hydroxide nanosheets. S2. Using interfacial polymerization, microcapsules with a core-shell structure are formed using carboxyl-terminated liquid fluororubber as the core material and thermoplastic polyurethane prepolymer as the wall material. After separation and drying, carboxyl-terminated liquid fluororubber microcapsules are obtained. S3. The hydrogenated styrene-butadiene-styrene block copolymer and processing aids are melt-plasticized, and then flame retardant synergist, stabilizer and polypyrrole-modified layered bimetallic hydroxide nanosheets prepared in S1 are added, and the mixture is mixed and dispersed to obtain a premix. S4. Heat the premixed material, add the carboxyl-terminated liquid fluororubber microcapsules and crosslinking agent prepared in S2, and perform melt blending and dynamic vulcanization under shear force. During this process, the wall material of the carboxyl-terminated liquid fluororubber microcapsule melts and the core material is released. Its carboxyl-terminated groups interact with the surface of the polypyrrole-modified layered double metal hydroxide nanosheets, and at the same time, partial cross-linking is initiated in the hydrogenated styrene-butadiene-styrene block copolymer matrix to form an interpenetrating network structure. S5. The dynamically vulcanized material is extruded, cooled, pelletized, and dried to obtain cable material granules.

7. The method for preparing the high tear-resistant cable material according to claim 6, characterized in that, In S1, the in-situ polymerization reaction is carried out under ice-water bath conditions, and the oxidant is ammonium persulfate.

8. The method for preparing the high tear-resistant cable material according to claim 6, characterized in that, In S2, the interface aggregation method includes: Carboxyl-terminated liquid fluororubber and thermoplastic polyurethane prepolymer were dissolved in an organic solvent as the oil phase, and an emulsifier was dissolved in water as the aqueous phase. The oil phase was then dripped into the aqueous phase under high-speed shearing to emulsify it, and then a curing agent was added to carry out the reaction.

9. The method for preparing the high tear-resistant cable material according to claim 6, characterized in that, In step S3, the melting and plasticizing temperature is 120-140℃; the mixing and dispersion time is 5-10 minutes; in step S4, the dynamic vulcanization temperature is 160-170℃, and the reaction time is 3-8 minutes; in step S5, the extrusion processing temperature is 150-160℃.

10. The method for preparing the high tear-resistant cable material according to claim 6, characterized in that, In step S3, a mixer is used for premixing; in step S4, a mixer is used for dynamic vulcanization; and in step S5, a twin-screw extruder is used for granulation.

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