An impact-resistant insulated busbar and a method for manufacturing the same

Abstract

This invention discloses an impact-resistant insulating busbar and its preparation method, relating to the field of power electronic device manufacturing technology. The busbar of this invention comprises a substrate, an adhesive layer, and an insulating layer. The insulating layer is prepared by a specific process using furan-functionalized polyolefin elastomer, bismaleimide crosslinking agent, catechol-borate modified EVA, liquid crystal elastomer / lead zirconate titanate core-shell material, hexagonal boron nitride nanosheets, 3,4-ethylenedioxythiophene, polyethylene glycol-polystyrene-perfluorohexyl ethyl acrylate block copolymer, and other functional additives. The impact-resistant insulating busbar prepared by this invention maintains excellent electrical insulation performance while also possessing high impact resistance, excellent heat resistance, long-term environmental stability, and interface reliability, making it suitable for power equipment operating under harsh conditions.

Description

Technical Field

[0001] This invention relates to the field of power electronic device manufacturing technology, specifically to an impact-resistant insulating busbar and its preparation method. Background Technology

[0002] As a key connecting component in power transmission and distribution systems, the core function of insulated busbars is to provide long-term, reliable insulation protection while ensuring electrical continuity. With the rapid development of new energy power generation, electric vehicles, and high-end equipment manufacturing, the operating environment of insulated busbars is becoming increasingly harsh. They not only need to withstand continuous power frequency or high DC voltage, but are also frequently exposed to complex conditions such as frequent mechanical vibration, impact, extreme temperature cycling, high humidity, and pollution. This poses unprecedented challenges to the comprehensive performance of insulation materials: requiring not only excellent initial insulation strength, but also maintaining stable and reliable performance under the long-term coupling of dynamic mechanical stress, thermal stress, and environmental stress—that is, achieving a balance and long-term durability across multiple performance aspects, including electrical, mechanical, thermal, and environmental properties.

[0003] Currently, the insulating materials widely used in insulating busbars mainly include thermosetting resins (such as epoxy resin and silicone resin) and their composites, as well as polyolefin materials (such as XLPE and XLPO) that are cross-linked by irradiation or chemical methods. These traditional material systems have revealed the following pressing technical bottlenecks in long-term application practice:

[0004] (1) Mechanical properties are difficult to improve in synergy with electrical insulation and heat resistance. Traditional modification methods often improve a certain property by adding inorganic fillers (such as silica and aluminum hydroxide), but this can easily lead to an imbalance in performance. For example, adding a large amount of filler to improve rigidity can impair the material's flexibility and impact resistance, making it prone to cracking under vibration conditions; ceramic fillers added to improve thermal conductivity may introduce electrical weaknesses, affecting insulation reliability. There is often a contradiction between the material's impact resistance and flexibility and its high strength, high thermal conductivity, and high heat resistance.

[0005] (2) Insufficient reliability of the material's internal structure and interlayer interfaces under dynamic stress. Under long-term thermal cycling, mechanical vibration, and thermal shock, defects such as microcracks and interface delamination are easily generated due to the mismatch in thermal expansion coefficients between the organic polymer matrix and the inorganic filler, as well as the easy aging of the bonding interface between the insulation layer and the metal busbar. These defects will become the starting point of partial discharge and the breakdown channel, seriously threatening long-term insulation safety. Existing technologies mostly rely on physical bonding or simple silane coupling agent treatment, and the interfacial bonding force is significantly weakened under dynamic stress.

[0006] (3) The lack of proactive mechanisms to cope with complex multi-factor aging processes limits long-term durability. When faced with multiple aging factors such as temperature fluctuations, continuous electric field effects, and environmental medium intrusion, the performance degradation of traditional insulating materials is a passive and irreversible process. For example, in humid and hot environments, moisture penetration accelerates the hydrolytic aging of materials and leads to surface leakage; under long-term electrical stress, the accumulation of space charge easily induces electrical dendrites. Most existing material systems are static structures and cannot dissipate impact energy, homogenize stress distribution, or repair early damage through their own physical or chemical changes, making it difficult to predict their lifespan and resulting in higher risks under extreme or unexpected operating conditions.

[0007] (4) Lack of synergistic design between surface properties and bulk properties. High humidity, salt spray, or polluted environments can easily form a continuous water film or conductive layer on the surface of insulating materials, causing surface discharge and flashover. Existing solutions mostly involve coating the surface with a hydrophobic coating, but such coatings have problems such as weak adhesion to the substrate, easy wear, and poor durability, and cannot form a stable integrated protective system with the bulk material.

[0008] In summary, while existing insulating busbar technology can meet basic insulation requirements, it suffers from significant shortcomings in performance balance, interface reliability, adaptive protection, and long-term service life when facing high-dynamic mechanical shocks, drastic temperature changes, long-term electrothermal aging, and the coupling effects of harsh environments. Therefore, there is an urgent need to develop a novel design concept and preparation method for insulating materials that can synergistically address these issues at the molecular and microstructural levels, producing impact-resistant insulating busbars that combine high insulation, robust impact resistance, excellent heat resistance, intelligent self-adaptation, and ultra-long service life. Summary of the Invention

[0009] The purpose of this invention is to provide an impact-resistant insulating busbar and its preparation method to solve the problems mentioned in the background art.

[0010] In a first aspect, the present invention provides an impact-resistant insulating busbar, comprising a substrate, an adhesive layer, and an insulating layer;

[0011] The substrate is a copper busbar or an aluminum alloy busbar;

[0012] The adhesive layer is obtained by immersing the substrate in a solvent containing bifunctional group molecules.

[0013] The bifunctional group molecule is 2-methyl-3-mercaptofuran or tris(2-furanyl)phosphine;

[0014] The mass fraction of the bifunctional group molecule in the solvent is 1-3%;

[0015] The solvent is any one or two of ethanol, propanol, isopropanol, butanone, acetone, toluene, and ethyl acetate;

[0016] The insulating layer comprises the following raw materials by weight:

[0017] 60-80 parts of furan-functionalized polyolefin elastomer;

[0018] 8-12 parts of bismaleimide crosslinking agent;

[0019] 20-40 parts of catechol-boron ester modified EVA;

[0020] 15-30 parts of liquid crystal elastomer / lead zirconate titanate core-shell material;

[0021] 18-27 parts of hexagonal boron nitride nanosheets;

[0022] 2-3 parts of 3,4-ethylenedioxythiophene;

[0023] 2-8 parts of polyethylene glycol-polystyrene-perfluorohexyl ethyl acrylate block copolymer;

[0024] Antioxidant 0.5-1 part;

[0025] 5-15 parts of silane-modified aluminum hydroxide micro powder;

[0026] Voltage stabilizer 0.5-3 parts.

[0027] As a preferred embodiment of the present invention, the preparation method of the furan-functionalized polyolefin elastomer is as follows:

[0028] Maleic anhydride-grafted polyolefin elastomer is added to a vacuum mixer and heated to 140-150℃ under nitrogen protection. The mixture is stirred and melted at 30-60 r / min for 3 min. 2-furan methylamine is added and the mixture is blended for 15-30 min. Terminal amino polyether and p-toluenesulfonic acid are added, and the mixture is heated to 160-180℃. Vacuum is applied for 1-2 min, and the mixture is stirred at 60-80 r / min for 20-40 min. The mixture is then quickly removed, pressed into tablets, cooled, and vacuum dried at 80℃ for 24-48 h to obtain furan-functionalized polyolefin elastomer.

[0029] The terminal amino polyether has a functionality of 2 and a number-average molecular weight of 1800-2200.

[0030] The mass ratio of maleic anhydride-grafted polyolefin elastomer, 2-furan methylamine, amino-terminated polyether, and p-toluenesulfonic acid is 100:(0.05-0.5):(4.1-10.2):(0.1-0.55).

[0031] It should be noted that, firstly, the primary amino group of furfurylamine undergoes a ring-opening amidation reaction with the anhydride group of the POE-g-MAH side chain, generating an amide bond and a carboxylic acid, thus firmly introducing the furan ring as a side chain. Secondly, the two primary amino groups of the terminal amino polyether can react with the carboxylic acid generated in the first step and the remaining anhydride (in small amounts). Under the action of the catalyst PTSA, the main reaction is the condensation amidation of the carboxylic acid and the amine, thereby chemically attaching the long-chain flexible polyether segment to the POE main chain. The resulting furan-functionalized polyolefin elastomer has a structure with POE as the main chain, with furan groups suspended in the side chains and furan-polyether long side chains connected by polyetheramines. In the insulating layer, the furan-functionalized polyolefin elastomer provides the main body's flexibility and impact resistance. Its furan groups can undergo a Diels-Alder cycloaddition reaction with the bismaleimide crosslinking agent to form a reversible dynamic covalent crosslinking network, endowing the insulating layer with inherent thermal remodeling potential and damage repair capabilities. The introduced flexible polyether segments act as micro-damping, further enhancing the material's low-temperature toughness and its ability to dissipate dynamic stress.

[0032] As a preferred embodiment of the present invention, the bismaleimide crosslinking agent is 1,1'-(methylenedi-4,1-phenylene)bismaleimide.

[0033] As a preferred embodiment of the present invention, the preparation method of the catechol-boron ester modified EVA is as follows:

[0034] A1. Maleic anhydride-grafted ethylene-vinyl acetate copolymer was dissolved in N,N-dimethylformamide containing trace amounts of deionized water and stirred at low speed at 50-60℃ for 2-4 hours. N-hydroxysuccinimide and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride were added, and the mixture was stirred for 0.5-1 hours under a nitrogen atmosphere at room temperature to obtain the reaction system solution.

[0035] The ratio of maleic anhydride-grafted ethylene-vinyl acetate copolymer, deionized water, N,N-dimethylformamide, N-hydroxysuccinimide and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride is 10g:0.36g:200mL:0.6g:1.15g.

[0036] A2. Prepare a mixed solution of N,N-dimethylformamide containing dopamine hydrochloride and triethylamine. Add the N,N-dimethylformamide mixed solution dropwise to the reaction system solution obtained in step A1 under nitrogen atmosphere, room temperature and in the dark. Stir the reaction for 12-24 hours to obtain a reaction solution. Add the reaction solution dropwise to a mixed solvent composed of diethyl ether and n-hexane under high-speed stirring to precipitate. Filter, wash and dry to obtain catechol-modified EVA.

[0037] The ratio of dopamine hydrochloride, triethylamine, and N,N-dimethylformamide in the N,N-dimethylformamide mixed solution containing dopamine hydrochloride and triethylamine is 0.5 g: 0.35 g: 10 mL.

[0038] The volume ratio of the N,N-dimethylformamide mixed solution to the reaction system solution is 1:20;

[0039] The volume ratio of diethyl ether to n-hexane in the mixed solvent is (1-2):(1-2);

[0040] The volume ratio of the reaction solution to the mixed solvent is 1:(8-12);

[0041] A3. Dissolve the catechol-modified EVA obtained in step A2 in tetrahydrofuran, add 1,4-phenyldiboronic acid and a trace amount of methanol, and react at room temperature with stirring for 6-12 h. Pour the product into 10 times the volume of petroleum ether, stir to induce precipitation, filter, collect the precipitate, wash 3 times with petroleum ether, and dry under vacuum at 40℃ for 24 h to obtain catechol-boron ester modified EVA.

[0042] The ratio of catechol-modified EVA, tetrahydrofuran, 1,4-phenyldiboronic acid, and methanol is 5g:50mL:0.18g:1.5g.

[0043] It should be noted that in step A1, trace amounts of water hydrolyze the anhydride groups of EVA-g-MAH to open the ring, generating EVA-COOH with two carboxyl groups in the side chain; subsequently, EDC and NHS synergistically activate the carboxyl groups, forming an active NHS ester intermediate. In step A2, the primary amino group of dopamine attacks this active ester, resulting in a highly efficient amidation reaction, thereby covalently grafting the catechol structural unit onto the EVA chain. Step A3 is the core step, where the two borate groups of 1,4-phenylenediboronic acid undergo specific and reversible complexation with the catechol groups on different EVA-Cat molecular chains, forming dynamic five-membered cyclic borate ester bonds, crosslinking the linear polymer into a network. Methanol is used as a regulator to control the crosslinking rate and density through competitive coordination. The resulting catechol-borate modified EVA is a crosslinked polymer network rich in dynamic borate ester bonds. In the insulating layer, this material acts as a dynamic sacrifice and stress buffer. When subjected to impact or stress, the borate ester bonds preferentially undergo reversible fracture, efficiently dissipating energy and significantly improving the impact resistance, tear resistance, and fatigue resistance of the composite material. Its dynamic properties also allow for bond recombination under heat or humidity stimulation, helping to release internal stress and inhibit microcrack propagation. This, in conjunction with the furan / maleimide dynamic network, endows the insulation layer with superior long-term reliability and environmental adaptability.

[0044] As a preferred embodiment of the present invention, the preparation steps of the liquid crystal elastomer / lead zirconate titanate core-shell material are as follows:

[0045] B1. Disperse nano-lead zirconate titanate particles in an ethanol solution with a mass fraction of 1-3% of 3-(isobutenoyloxy)propyltrimethoxysilane, adjust the pH to 4-5, reflux and stir at 70℃ for 12-24h, centrifuge, wash, and obtain KH-570 modified PZT particles.

[0046] The particle size of the nano-lead zirconate titanate particles is 100-200 nm;

[0047] The volume ratio of ethanol to deionized water in the ethanol solution is 19:1;

[0048] The ratio of the nano-lead zirconate titanate particles to the ethanol solution is 1g:(40-60)mL;

[0049] B2. Disperse the KH-570 modified PZT particles obtained in step B1 in N,N-dimethylformamide, add diacrylate monomer containing liquid crystal units, pentaerythritol tetrakis(3-mercaptopropionic acid) chain transfer agent and azobisisobutyronitrile free radical initiator, stir and react at 75-85℃ under nitrogen atmosphere for 6-10h, centrifuge, wash with N,N-dimethylformamide and acetone alternately 3 times, vacuum dry at 80℃ for 12-24h, and irradiate under ultraviolet light (wavelength 365nm) for 1-2h to obtain liquid crystal elastomer / lead zirconate titanate core-shell material (LCE@PZT core-shell material);

[0050] The diacrylate monomer containing the liquid crystal unit is 1,4-bis-[4-(3-acryloyloxypropoxy)benzoyloxy]-2-methylbenzene, i.e., RM257 monomer, or 1,4-bis-[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-methylbenzene, i.e., RM82 monomer.

[0051] The ratio of the KH-570 modified PZT particles, N,N-dimethylformamide, pentaerythritol tetrakis(3-mercaptopropionic acid) chain transfer agent, azobisisobutyronitrile free radical initiator, and diacrylate monomer containing liquid crystal units is 1g:20mL:0.2g:0.02g:2g.

[0052] It should be noted that in step B1, the silane coupling agent KH-570 (3-(isobutenoyloxy)propyltrimethoxysilane) undergoes hydrolysis and condenses with the hydroxyl groups on the surface of PZT particles, introducing polymeric active double bonds (C=C) onto its surface. In step B2, under the action of the thermal initiator AIBN, the double bonds on the PZT surface, the liquid crystal monomer RM257 (containing two acrylate groups), and the multifunctional chain transfer agent pentaerythritol tetrakis(3-mercaptopropionic acid) ester (PETMP, containing four thiol groups) undergo a copolymerization reaction. This reaction belongs to the combination of mercapto-olefin click chemistry and free radical copolymerization, forming a chemically cross-linked liquid crystal polymer network shell around the PZT core through surface grafting and cross-linking. Ultraviolet irradiation is used to complete the later curing. The obtained LCE@PZT core-shell material has a core-shell structure, with PZT as the core providing piezoelectric effect; and the cross-linked liquid crystal polymer as the shell, exhibiting thermally induced phase transition properties. In the insulation layer, the LCE@PZT core-shell material acts as a filler with a smart dual-response function: when subjected to mechanical shock or vibration, the PZT core can convert part of the mechanical energy into micro-electrical energy and dissipate it, playing an active damping role; when the temperature changes (such as the busbar heating up), the liquid crystal cells of the LCE shell undergo an ordered-disorder phase transition, resulting in a significant change in its modulus (hardening at high temperatures), thereby adaptively and locally enhancing the material's resistance to deformation at high temperatures and improving the thermomechanical stability of the insulation system.

[0053] As a preferred embodiment of the present invention, the preparation steps of the polyethylene glycol-polystyrene-perfluorohexyl ethyl acrylate block copolymer are as follows:

[0054] C1. Under a nitrogen atmosphere, polyethylene glycol monomethyl ether, 2-bromoisobutyryl bromide and triethylamine were reacted in an ice-water bath for 12 h, and the reaction was continued at room temperature for 24 h. After filtration, dichloromethane was added to the filtrate, and the mixture was washed, filtered, and distilled under reduced pressure to obtain Br-PEG.

[0055] The molar ratio of polyethylene glycol monomethyl ether, 2-bromoisobutyryl bromide, and triethylamine is 1:1.5:2;

[0056] The number-average molecular weight of the polyethylene glycol monomethyl ether is 750;

[0057] C2. Under a nitrogen atmosphere, Br-PEG, cuprous bromide, pentamethyldiethylenetriamine and styrene were mixed and reacted at 110°C for 4 h to obtain a crude product. The crude product was dissolved in tetrahydrofuran, and the resulting solution was passed through a neutral alumina column to remove the catalyst. The product was then precipitated in petroleum ether as a precipitant. The precipitation-dissolution-precipitation process was repeated 3 times. The resulting product was dried in a vacuum drying oven at 30°C for 24 h to obtain a bromine-terminated polyethylene glycol-polystyrene copolymer.

[0058] The molar ratio of Br-PEG, cuprous bromide, pentamethyldiethylenetriamine, and styrene is 1:1:1:400;

[0059] The ratio of the crude product to tetrahydrofuran is 1g:(10-20)mL;

[0060] C3. Under a nitrogen atmosphere, bromine-terminated polyethylene glycol-polystyrene copolymer, cuprous bromide, pentamethyldiethylenetriamine, and perfluorohexyl ethyl acrylate were reacted at 90°C for 10 h to obtain a primary product. The primary product was dissolved in tetrahydrofuran, and the resulting solution was passed through a neutral alumina column to remove the catalyst. The product was then precipitated in petroleum ether, and the precipitation-dissolution-precipitation process was repeated three times to obtain a secondary product. The secondary product was dried in a vacuum drying oven at 30°C for 24 h to obtain a polyethylene glycol-polystyrene-perfluorohexyl ethyl acrylate block copolymer.

[0061] The molar ratio of the brominated polyethylene glycol-polystyrene copolymer, cuprous bromide, pentamethyldiethylenetriamine and perfluorohexyl ethyl acrylate is 1:1:1:100.

[0062] The ratio of the primary product to tetrahydrofuran is 1 g:(15-25) mL.

[0063] It should be noted that in step C1, the terminal hydroxyl groups of polyethylene glycol monomethyl ether (mPEG) are esterified with 2-bromoisobutyryl bromide, transforming it into an atom transfer radical polymerization (ATRP) initiator (Br-PEG). In step C2, Br-PEG is used as a macroscopic initiator to initiate styrene polymerization in a CuBr / PMDETA catalytic system, yielding a bromine-terminated PEG-b-PS diblock copolymer. In step C3, the bromine end of this diblock copolymer is used as the initiation site to initiate the polymerization of perfluorohexyl ethyl acrylate (FA), ultimately yielding a triblock copolymer. The structural characteristics of the polyethylene glycol-polystyrene-perfluorohexyl ethyl acrylate block copolymer prepared by atom transfer radical polymerization are that it simultaneously contains hydrophilic PEG segments, hydrophobic PS segments that provide mechanical support, and fluorinated PFA segments with extremely low surface energy. In the insulating layer, this block copolymer is a highly efficient structural surface modifier. During processing and molding, due to the differences in compatibility between each segment and the matrix, its fluorinated segments (PFA) spontaneously migrate to the material surface, forming a durable and robust superhydrophobic layer, improving the insulation layer's resistance to staining, hydrophobicity, and tracking. Simultaneously, its hydrophilic segments (PEG) and intermediate segments (PS) are anchored within the matrix, ensuring the stability of the surface functional layer. This addresses surface issues from the material's core, avoiding the drawbacks of easy wear and detachment of the surface layer.

[0064] As a preferred embodiment of the present invention, one or more of antioxidants 1010, 168, 1076, BHT, DLTP, and TNPP are used.

[0065] As a preferred embodiment of the present invention, the voltage stabilizer is pyromellitic diimide or N,N'-dimethyl-3,4,9,10-perylenetetracarboxylate diimide.

[0066] A second aspect of the present invention provides a method for preparing an impact-resistant insulating busbar, comprising the following steps:

[0067] S1. The substrate is degreased, sandblasted and roughened, cleaned and dried in sequence. It is then immersed in a solvent containing bifunctional group molecules at 50-60℃ for 0.5-1h. After being taken out and washed with the corresponding solvent, it is vacuum dried at 40℃ to obtain the motherboard with adhesive layer.

[0068] It should be noted that step S1 constructs a chemically bonded adhesive layer on the surface of the metal substrate through molecular self-assembly. The chemically bonded adhesive layer is the adhesive layer in the impact-resistant insulating busbar structure provided in the first aspect of the present invention. One end of the selected bifunctional group molecule is a strong metal-binding group (thiol group for copper, phosphine group for aluminum), and the other end is a furan ring, which can serve as an active site for the Diels-Alder crosslinking reaction of furan-functionalized polyolefin elastomer in the subsequent insulating layer. While realizing the chemical bridging between the metal substrate and the organic insulating layer, it forms a strong and durable interface, significantly improving the adhesion stability and long-term reliability of the insulating layer under dynamic stresses such as thermal cycling and mechanical vibration, and reducing the risk of interface delamination.

[0069] S2. Weigh the insulating layer raw materials according to the weight parts. Mix furan-functionalized polyolefin elastomer, catechol-boron ester modified EVA, liquid crystal elastomer / lead zirconate titanate core-shell material, hexagonal boron nitride nanosheets, polyethylene glycol-polystyrene-polyperfluorohexyl ethyl acrylate block copolymer, antioxidant, silane surface-modified aluminum hydroxide micro powder and voltage stabilizer in a mixer at 120-140℃ and 30r / min speed for 2-3min. Add 3,4-ethylenedioxythiophene, increase the speed to 60-80r / min and mix for 10-15min. Cool to 90-95℃, add bismaleimide crosslinking agent, mix well, sheet, cool and granulate to obtain insulating layer composite masterbatch.

[0070] S3. Place the busbar with adhesive layer obtained in step S1 into a preheated mold, fill it with the composite masterbatch of insulating layer obtained in step S2, hot press it at a temperature of 170-180℃ and a pressure of 15-20MPa for 15-25 minutes, hold the pressure and cool it before demolding to obtain the impact-resistant insulating busbar.

[0071] It should be noted that the insulation layer formulation, through molecular design and multi-component synergy, constructs a composite system that combines dynamic adaptability and structural stability. Furan-functionalized polyolefin elastomers and bismaleimide crosslinking agents form a dynamic covalent network via a reversible Diels-Alder reaction, endowing the material with intrinsic ductility and potential self-healing capabilities. The dynamic borate bonds in the catechol-boronate modified EVA act as reversible sacrificial bonds, preferentially breaking under impact to dissipate energy and enhance toughness. In the liquid crystal elastomer / lead zirconate titanate core-shell material, the piezoelectric ceramic core converts mechanical vibration into minute electrical energy dissipation, while the liquid crystal shell reversibly adjusts its local modulus with temperature changes, achieving intelligent damping. Hexagonal boron nitride nanosheets are well dispersed with the assistance of 3,4-ethylenedioxythiophene, constructing an effective thermal conductivity pathway. Silane-modified aluminum hydroxide micropowder can improve the flame retardancy of the insulation layer and inhibit arc propagation and carbonization. Polyethylene glycol-polystyrene-perfluorohexyl ethyl acrylate block copolymers form a stable hydrophobic layer through surface migration. These components work synergistically through chemical and physical interactions, enabling the insulating layer to maintain structural integrity and functional stability under mechanical, thermal, and electrical stresses through multiple energy dissipation and adaptive mechanisms.

[0072] It is worth noting that in practical use, this insulating busbar copes with complex operating conditions through the aforementioned synergistic mechanism. When encountering external mechanical shocks or vibrations, the dynamic covalent network, sacrificial bonds, and piezoelectric-liquid crystal core-shell filler work together to dissipate energy through multiple pathways, including reversible bond breakage, phase transitions, and mechanical-to-electrical energy conversion, thus buffering the impact. Under long-term energized heating and fluctuating ambient temperature, the thermally conductive network effectively dissipates heat, the liquid crystal shell adaptively adjusts the interface stiffness, and the dynamic network releases thermal stress, all working together to maintain interface stability and prevent delamination. In high-humidity or polluted environments, the surface hydrophobic layer inhibits water film formation, while the internal dynamic bonds can recombine to compensate for damp-heat stress. This passive defense-active adaptation integrated protection system, constructed by multiple intelligent response mechanisms within the material, ensures its long-term insulation reliability under multiple stresses, including electrical, thermal, and environmental stresses.

[0073] Compared with the prior art, the present invention has the following beneficial effects:

[0074] (1) A multi-layered, dynamically synergistic intelligent protection mechanism has been constructed. This invention is not a simple blend, but rather integrates multiple response units, such as a furan / bismaleimide reversible covalent network, a borate ester dynamic sacrificial bond, and a piezoelectric-liquid crystal intelligent core-shell filler, through chemical synthesis. Under mechanical impact, thermal cycling, and electric field action, these units can synergistically achieve intelligent response and resistance to complex dynamic stresses at the intrinsic level of the material, improving the limitations of traditional static insulating materials.

[0075] (2) Improved long-term reliability under extreme multi-factor coupled conditions. In traditional solutions, the impact resistance, heat resistance, and environmental aging resistance of insulating materials are often mutually restrictive. This invention, through precise design and interface control of each functional component, enables the material to simultaneously possess excellent impact toughness, efficient thermal management capabilities, adaptive interface stability, and durable environmental protection. It can systematically cope with the accelerated aging challenges caused by the interplay of mechanical, thermal, electrical, and environmental factors in actual operation, thus extending its service life.

[0076] (3) Integrated design from substrate to interface is achieved. This invention conducts material design across all levels, from molecular-level interfacial bonding (adhesive layer) of the metal substrate to the synergistic effect of multifunctional fillers and surface property regulation of the insulating phase (insulating layer). This integrated design across the entire chain ensures an excellent balance in macroscopic performance and high stability in microstructure of the material system, avoiding weak links caused by interlayer mismatch or single function, and improving the overall performance and reliability of the insulating busbar. Detailed Implementation

[0077] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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.

[0078] Preparation Example 1

[0079] The preparation method of furan-functionalized polyolefin elastomers is as follows:

[0080] 100g of maleic anhydride-grafted polyolefin elastomer was added to a vacuum mixer and heated to 145℃ under nitrogen protection. The mixture was stirred and melted at 45r / min for 3min. 0.2g of 2-furan methylamine was added and the mixture was blended for 25min. 8.2g of amino-terminated polyether and 0.33g of p-toluenesulfonic acid were added, the mixture was heated to 170℃, vacuumed for 1min, and stirred at 70r / min for 30min. The mixture was quickly removed, pressed into tablets, cooled, and vacuum dried at 80℃ for 24h to obtain furan-functionalized polyolefin elastomer.

[0081] Preparation Example 2

[0082] The preparation method of catechol-boron ester modified EVA is as follows:

[0083] A1. 10g of maleic anhydride-grafted ethylene-vinyl acetate copolymer was dissolved in 200mL of N,N-dimethylformamide containing 0.36g of deionized water. The mixture was stirred at low speed at 55℃ for 3h. Then, 0.6g of N-hydroxysuccinimide and 1.15g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride were added. The mixture was stirred for 0.5h under a nitrogen atmosphere at room temperature to obtain the reaction system solution.

[0084] A2. Prepare a 10 mL N,N-dimethylformamide mixed solution containing 0.5 g dopamine hydrochloride and 0.35 g triethylamine. Add the 10 mL N,N-dimethylformamide mixed solution dropwise to 200 mL of the reaction system solution obtained in step A1 under nitrogen atmosphere, room temperature and in the dark. Stir the reaction for 12 h to obtain a reaction solution. Add the reaction solution dropwise to a 10-fold volume of a mixed solvent consisting of diethyl ether and n-hexane in a 1:1 volume ratio, stirred at high speed, to precipitate the precipitate. Filter, wash, and dry to obtain catechol-modified EVA.

[0085] A3. Dissolve 5g of the catechol-modified EVA obtained in step A2 in 50mL of tetrahydrofuran, add 0.18g of 1,4-phenyldiboronic acid and 1.5g of methanol, and react at room temperature with stirring for 6h. Pour the product into 10 times the volume of petroleum ether, stir to induce precipitation, filter, collect the precipitate, wash 3 times with petroleum ether, and dry under vacuum at 40℃ for 24h to obtain catechol-boron ester modified EVA.

[0086] Preparation Example 3

[0087] The preparation steps of the liquid crystal elastomer / lead zirconate titanate core-shell material are as follows:

[0088] B1. Disperse 1g of nano-lead zirconate titanate particles in 50mL of 2% ethanol solution of 3-(isobutenoyloxy)propyltrimethoxysilane, adjust the pH to 4.5, reflux and stir at 70℃ for 18h, centrifuge, wash, and obtain KH-570 modified PZT particles.

[0089] The particle size of the nano-lead zirconate titanate particles is 100-200 nm;

[0090] The volume ratio of ethanol to deionized water in the ethanol solution is 19:1;

[0091] B2. Disperse 1g of KH-570 modified PZT particles obtained in step B1 in 20mL of N,N-dimethylformamide, add 2g of RM257 monomer, 0.2g of pentaerythritol tetrakis(3-mercaptopropionic acid) chain transfer agent and 0.02g of azobisisobutyronitrile free radical initiator, stir and react for 8h under nitrogen atmosphere and 80℃, centrifuge, wash three times alternately with N,N-dimethylformamide and acetone, vacuum dry at 80℃ for 18h, and irradiate under ultraviolet light (wavelength 365nm) for 1h to obtain liquid crystal elastomer / lead zirconate titanate core-shell material (LCE@PZT core-shell material).

[0092] Preparation Example 4

[0093] The preparation steps of the polyethylene glycol-polystyrene-perfluorohexyl ethyl acrylate block copolymer are as follows:

[0094] C1. Under a nitrogen atmosphere, 0.5 g of polyethylene glycol monomethyl ether, 0.23 g of 2-bromoisobutyryl bromide and 0.13 g of triethylamine were reacted in an ice-water bath for 12 h, and the reaction was continued at room temperature for 24 h. After filtration, dichloromethane was added to the filtrate, and the mixture was washed, filtered, and distilled under reduced pressure to obtain Br-PEG.

[0095] The number-average molecular weight of the polyethylene glycol monomethyl ether is 750;

[0096] C2. Under a nitrogen atmosphere, 0.6 g Br-PEG, 0.1 g cuprous bromide, 0.13 g pentamethyldiethylenetriamine and 27.8 g styrene were mixed and reacted at 110 °C for 4 h to obtain a crude product. The crude product was dissolved in 430 mL tetrahydrofuran, and the resulting solution was passed through a neutral alumina column to remove the catalyst. The product was then precipitated in petroleum ether as a precipitant. The precipitation-dissolution-precipitation process was repeated 3 times. The resulting product was dried in a vacuum drying oven at 30 °C for 24 h to obtain a bromine-terminated polyethylene glycol-polystyrene copolymer.

[0097] C3. Under a nitrogen atmosphere, 28.4 g of brominated polyethylene glycol-polystyrene copolymer, 0.1 g of cuprous bromide, 0.13 g of pentamethyldiethylenetriamine, and 27.9 g of perfluorohexyl ethyl acrylate were reacted at 90 °C for 10 h to obtain a primary product. The primary product was dissolved in 1130 mL of tetrahydrofuran, and the resulting solution was passed through a neutral alumina column to remove the catalyst. The catalyst was then precipitated in petroleum ether, and the precipitation-dissolution-precipitation process was repeated three times to obtain a secondary product. The secondary product was dried in a vacuum drying oven at 30 °C for 24 h to obtain a polyethylene glycol-polystyrene-perfluorohexyl ethyl acrylate block copolymer.

[0098] Example 1

[0099] A method for preparing an impact-resistant insulating busbar includes the following steps:

[0100] S1. T2 copper busbar is degreased, sandblasted and roughened, cleaned and dried in sequence. It is then immersed in acetone containing 2% 2-methyl-3-mercaptofuran at 55°C for 1 hour. After being taken out and washed with acetone 3 times, it is vacuum dried at 40°C to obtain the busbar with adhesive layer.

[0101] S2. Weigh the insulating layer raw materials according to the weight parts. 70 parts of furan-functionalized polyolefin elastomer, 30 parts of catechol-boron ester modified EVA, 24 parts of liquid crystal elastomer / lead zirconate titanate core-shell material, 23 parts of hexagonal boron nitride nanosheets, 5 parts of polyethylene glycol-polystyrene-polyperfluorohexyl ethyl acrylate block copolymer, 0.8 parts of antioxidant 1010, 10 parts of silane surface-modified aluminum hydroxide micro powder and 2 parts of pyromellitic diamilide are mixed in a mixer at 130°C and 30 r / min for 3 min. 2.5 parts of 3,4-ethylenedioxythiophene are added, the speed is increased to 60 r / min and mixed for 15 min. The temperature is lowered to 95°C and 10 parts of 1,1'-(methylenedi-4,1-phenylene)bismaleimide are added. After mixing, the mixture is sheeted, cooled and granulated to obtain the insulating layer composite masterbatch.

[0102] S3. Place the busbar with adhesive layer obtained in step S1 into a preheated mold, fill it with the composite masterbatch of insulation layer obtained in step S2, hot press it at 180℃ and 15Pa for 20 minutes, hold the pressure and cool it before demolding to obtain the impact-resistant insulation busbar.

[0103] In this embodiment, some of the raw materials used are the same as those obtained in Preparation Examples 1-4, and the other examples are the same.

[0104] Example 2

[0105] A method for preparing an impact-resistant insulating busbar includes the following steps:

[0106] S1. T2 copper busbar is degreased, sandblasted and roughened, cleaned and dried in sequence. It is then immersed in acetone containing 2% 2-methyl-3-mercaptofuran at 55°C for 1 hour. After being taken out and washed with acetone 3 times, it is vacuum dried at 40°C to obtain the busbar with adhesive layer.

[0107] S2. Weigh the insulating layer raw materials according to the weight parts. 60 parts of furan-functionalized polyolefin elastomer, 20 parts of catechol-boron ester modified EVA, 15 parts of liquid crystal elastomer / lead zirconate titanate core-shell material, 20 parts of hexagonal boron nitride nanosheets, 3 parts of polyethylene glycol-polystyrene-polyperfluorohexyl ethyl acrylate block copolymer, 0.5 parts of antioxidant 1010, 6 parts of silane surface-modified aluminum hydroxide micro powder and 1 part of pyromellitic diamilide are mixed in a mixer at 130℃ and 30r / min for 3min. 2 parts of 3,4-ethylenedioxythiophene are added, the speed is increased to 60r / min and mixed for 15min. The temperature is lowered to 95℃ and 8 parts of 1,1'-(methylenedi-4,1-phenylene)bismaleimide are added. After mixing, the mixture is sheeted, cooled and granulated to obtain the insulating layer composite masterbatch.

[0108] S3. Place the busbar with adhesive layer obtained in step S1 into a preheated mold, fill it with the composite masterbatch of insulation layer obtained in step S2, hot press it at 180℃ and 15Pa for 20 minutes, hold the pressure and cool it before demolding to obtain the impact-resistant insulation busbar.

[0109] Example 3

[0110] A method for preparing an impact-resistant insulating busbar includes the following steps:

[0111] S1. T2 copper busbar is degreased, sandblasted and roughened, cleaned and dried in sequence. It is then immersed in acetone containing 2% 2-methyl-3-mercaptofuran at 55°C for 1 hour. After being taken out and washed with acetone 3 times, it is vacuum dried at 40°C to obtain the busbar with adhesive layer.

[0112] S2. Weigh the insulating layer raw materials according to the weight parts. 80 parts of furan-functionalized polyolefin elastomer, 40 parts of catechol-boron ester modified EVA, 30 parts of liquid crystal elastomer / lead zirconate titanate core-shell material, 25 parts of hexagonal boron nitride nanosheets, 7 parts of polyethylene glycol-polystyrene-polyperfluorohexyl ethyl acrylate block copolymer, 1 part of antioxidant 1010, 14 parts of silane surface-modified aluminum hydroxide micro powder and 3 parts of pyromellitic diamilide are mixed in a mixer at 130℃ and 30r / min for 3min. 3 parts of 3,4-ethylenedioxythiophene are added, the speed is increased to 60r / min and mixed for 15min. The temperature is lowered to 95℃, 12 parts of 1,1'-(methylenedi-4,1-phenylene)bismaleimide are added, mixed evenly, sheeted, cooled and granulated to obtain the insulating layer composite masterbatch.

[0113] S3. Place the busbar with adhesive layer obtained in step S1 into a preheated mold, fill it with the composite masterbatch of insulation layer obtained in step S2, hot press it at 180℃ and 15Pa for 20 minutes, hold the pressure and cool it before demolding to obtain the impact-resistant insulation busbar.

[0114] Comparative Example 1

[0115] The difference between this comparative example and Example 1 is that the furan-functionalized polyolefin elastomer prepared in Example 1 was not added; instead, an equal part by weight of maleic anhydride-grafted polyolefin elastomer was added.

[0116] Comparative Example 2

[0117] The difference between this comparative example and Example 1 is that the catechol-boron ester modified EVA obtained in Preparation Example 2 was not added; instead, an equal part by weight of maleic anhydride-grafted ethylene-vinyl acetate copolymer was added.

[0118] Comparative Example 3

[0119] The difference between this comparative example and Example 1 is that the liquid crystal elastomer / lead zirconate titanate core-shell material prepared in Preparation Example 3 was not added.

[0120] test:

[0121] I. Mechanical Performance Testing

[0122] Impact strength: According to GB / T 1043.1-2008 "Determination of impact properties of simply supported plastic beams", the insulation layer sample was tested using a pendulum impact tester, and the impact strength (kJ / m) was recorded. 2 ).

[0123] Tensile properties: According to GB / T 1040.2-2022 Determination of tensile properties of plastics, the tensile strength (MPa) and elongation at break (%) of the insulation layer specimens were tested using a universal testing machine.

[0124] The test results are shown in Table 1.

[0125] II. Electrical Insulation Performance Test

[0126] Power frequency electrical strength: According to GB / T 1408.1-2016 Test method for electrical strength of insulating materials, the continuous voltage increase method is used to test the breakdown field strength (kV / mm) of the insulation layer sample at power frequency (50Hz).

[0127] Volume resistivity: According to GB / T 31838.2-2019 Dielectric and resistive properties of solid insulating materials - Part 2: Resistive properties (DC method) - Volume resistivity and volume resistivity, the volume resistivity (Ω·cm) of the insulating layer sample is tested using a high resistance meter.

[0128] The test results are shown in Table 1.

[0129] III. Thermal Performance and Thermal Conductivity Testing

[0130] Thermal conductivity: According to GB / T 10297-2015 Determination of thermal conductivity of non-metallic solid materials by hot wire method, the thermal conductivity (W / (m·K)) of the insulating layer sample was tested using a thermal conductivity meter.

[0131] Heat distortion temperature (HDT): According to GB / T 1634.2-2019 Determination of heat distortion temperature of plastics under load, the heat distortion temperature (°C) of the insulation layer sample is tested under a load of 1.8 MPa.

[0132] The test results are shown in Table 2.

[0133] IV. Environmental Adaptability Testing

[0134] Electrical property retention rate after constant temperature and humidity aging: The sample was placed in a constant temperature and humidity chamber at 85℃ and 85% relative humidity for 1000h. After removal, it was allowed to recover under standard conditions for 24h, and its volume resistivity was tested. The retention rate (%) relative to the initial value was calculated using the following formula:

[0135] Resistivity retention rate after damp heat (%) = ρ1 / ρ0 × 100%;

[0136] in:

[0137] ρ1—Volume resistivity of the sample after damp heat aging and recovery;

[0138] ρ0—Volume resistivity of the sample before damp heat aging treatment;

[0139] Insulation resistance after salt spray test: According to GB / T 2423.17-2024 Environmental Testing Part 2: Test Methods Test Ka: Salt Spray, the insulating busbar samples were subjected to a 96-hour neutral salt spray test. After the test, the samples were cleaned and dried, and their surface insulation resistance (MΩ) was measured using an insulation resistance tester (500V DC).

[0140] The test results are shown in Table 2.

[0141] V. Long-term reliability assessment

[0142] Mechanical property retention rate after hot air aging: The insulation layer sample was aged in a 135℃ forced-air drying oven for 168 hours. After removal, its tensile strength and elongation at break were tested, and the retention rate (%) relative to the initial value was calculated using the following formula:

[0143] Tensile strength retention rate after heat aging (%) = σ1 / σ0 × 100%;

[0144] in:

[0145] σ1—Tensile strength of the specimen after hot air aging;

[0146] σ0—Tensile strength of the specimen before hot air aging treatment;

[0147] Electrical aging life (tracking resistance): According to GB / T 4207-2022 Determination of Tracking Resistance Index and Comparative Tracking Index of Solid Insulating Materials, the comparative tracking index (CTI) of the insulating layer sample is tested.

[0148] The test results are shown in Table 2.

[0149] VI. Summary of Results

[0150] Table 1: Test Results of Mechanical and Electrical Insulation Properties

[0151]

[0152] Table 2: Test results of thermal performance and thermal conductivity, environmental adaptability and long-term reliability.

[0153]

[0154] VII. Discussion of Results

[0155] As can be seen from Tables 1 and 2, the impact-resistant insulating busbars prepared in Examples 1-3 of the present invention have excellent comprehensive performance balance, and exhibit excellent performance in terms of impact toughness, electrical insulation strength, thermal conductivity, heat resistance and long-term environmental reliability.

[0156] Compared to Examples 1-3, the properties of Comparative Example 1 decreased significantly, especially the impact strength, elongation at break, and performance retention after thermal aging. This demonstrates that the dynamic reversible covalent network constructed from furan / bismaleimide plays an irreplaceable role in improving the intrinsic toughness of the material, absorbing impact energy, and releasing long-term thermal stress through reversible bond fracture-recombination.

[0157] Compared to Examples 1-3, Comparative Example 2 showed a significant decrease in impact strength, damp heat stability, and insulation resistance after salt spray. This indicates that the dynamic borate ester bond, acting as a sacrificial bond, effectively dissipates energy under instantaneous impact and alleviates interfacial stress through dynamic bond recombination in a damp heat environment, which is crucial for maintaining interfacial integrity and insulation stability in humid environments.

[0158] Compared to Examples 1-3, Comparative Example 3 showed a decrease in impact strength, thermal conductivity, and tracking index (CTI). This indicates that the piezoelectric-liquid crystal core-shell filler plays a core role in intelligent damping and adaptive stiffness through the piezoelectric effect and liquid crystal phase transition, and its shell structure also helps to improve the filler-matrix interface.

[0159] It should be noted that hexagonal boron nitride nanosheets are the core filler for constructing efficient thermal conductivity pathways, and the integrity of the h-BN network is the dominant factor in thermal conductivity.

[0160] LCE@PZT core-shell materials synergistically contribute to maintaining and optimizing the integrity of the h-BN-based thermally conductive network, but their impact on thermal conductivity is less significant than that of the key components constructing the basic thermally conductive network. Comparative Example 1 lacks furan-functionalized polyolefin elastomers; the absence of these elastomers leads to a decreased ability of the matrix to fix h-BN, resulting in uneven h-BN dispersion, disrupting the thermally conductive structure, and achieving the lowest thermal conductivity. Comparative Example 2 lacks catechol-boron ester modified EVA; the lack of dynamic boron ester bonds prevents the effective release of internal stress accumulated during processing and cooling, leading to more micro-interface defects or microcracks. These defects become phonon scattering centers, thus reducing overall thermal conductivity. The PZT core has generally low thermal conductivity, and the LCE shell, being a polymer material, contributes far less thermal conductivity than h-BN. Therefore, even if LCE@PZT is completely removed in Comparative Example 3, as long as the h-BN network is well constructed, the basic thermal conductivity can still be maintained at a high level. Its core role lies in piezoresistive damping and liquid crystal phase transition. Its improvement on thermal conductivity is an indirect synergy, which can improve the local interface and assist in stress distribution (preventing microcracks from destroying the thermal conductivity path).

[0161] In summary, through the creative design and synergy of various functional components, this invention has successfully produced an impact-resistant insulating busbar that can maintain high reliability under harsh working conditions.

[0162] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0163] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the scope defined by the invention, and all such modifications and additions should fall within the protection scope of the present invention.

Claims

1. An impact-resistant insulating busbar, characterized in that: Includes substrate, adhesive layer and insulating layer; The substrate is a copper busbar or an aluminum alloy busbar; The adhesive layer is obtained by immersing the substrate in a solvent containing bifunctional group molecules. The bifunctional group molecule is 2-methyl-3-mercaptofuran or tris(2-furanyl)phosphine; The insulating layer comprises the following raw materials by weight: 60-80 parts of furan-functionalized polyolefin elastomer; 8-12 parts of bismaleimide crosslinking agent; 20-40 parts of catechol-boron ester modified EVA; 15-30 parts of liquid crystal elastomer / lead zirconate titanate core-shell material; 18-27 parts of hexagonal boron nitride nanosheets; 2-3 parts of 3,4-ethylenedioxythiophene; 2-8 parts of polyethylene glycol-polystyrene-perfluorohexyl ethyl acrylate block copolymer; Antioxidant 0.5-1 part; 5-15 parts of silane-modified aluminum hydroxide micro powder; Voltage stabilizer 0.5-3 parts; The preparation method of the furan-functionalized polyolefin elastomer is as follows: Maleic anhydride-grafted polyolefin elastomer is added to a vacuum mixer and heated to 140-150℃ under nitrogen protection. The mixture is stirred and melted at 30-60 r / min for 3 min. 2-furan methylamine is added and the mixture is blended for 15-30 min. Terminal amino polyether and p-toluenesulfonic acid are added, and the mixture is heated to 160-180℃. Vacuum is applied for 1-2 min, and the mixture is stirred at 60-80 r / min for 20-40 min. The mixture is then quickly removed, pressed into tablets, cooled, and vacuum dried at 80℃ for 24-48 h to obtain furan-functionalized polyolefin elastomer. The preparation method of the catechol-boron ester modified EVA is as follows: A1. Maleic anhydride-grafted ethylene-vinyl acetate copolymer was dissolved in N,N-dimethylformamide containing trace amounts of deionized water and stirred at low speed at 50-60℃ for 2-4 hours. N-hydroxysuccinimide and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride were added, and the mixture was stirred for 0.5-1 hours under a nitrogen atmosphere at room temperature to obtain the reaction system solution. A2. Prepare a mixed solution of N,N-dimethylformamide containing dopamine hydrochloride and triethylamine. Add the N,N-dimethylformamide mixed solution dropwise to the reaction system solution obtained in step A1 under nitrogen atmosphere, room temperature and in the dark. Stir the reaction for 12-24 hours to obtain a reaction solution. Add the reaction solution dropwise to a mixed solvent composed of diethyl ether and n-hexane under high-speed stirring to precipitate. Filter, wash and dry to obtain catechol-modified EVA. A3. Dissolve the catechol-modified EVA obtained in step A2 in tetrahydrofuran, add 1,4-phenyldiboronic acid and a trace amount of methanol, and react at room temperature with stirring for 6-12 h. Pour the product into 10 times the volume of petroleum ether, stir to induce precipitation, filter, collect the precipitate, wash 3 times with petroleum ether, and dry under vacuum at 40℃ for 24 h to obtain catechol-boron ester modified EVA. The preparation steps of the liquid crystal elastomer / lead zirconate titanate core-shell material are as follows: B1. Disperse nano-lead zirconate titanate particles in an ethanol solution with a mass fraction of 1-3% of 3-(isobutenoyloxy)propyltrimethoxysilane, adjust the pH to 4-5, reflux and stir at 70℃ for 12-24h, centrifuge, wash, and obtain KH-570 modified PZT particles. B2. Disperse the KH-570 modified PZT particles obtained in step B1 in N,N-dimethylformamide, add diacrylate monomer containing liquid crystal units, pentaerythritol tetrakis(3-mercaptopropionic acid) chain transfer agent and azobisisobutyronitrile free radical initiator, stir and react at 75-85℃ for 6-10h under nitrogen atmosphere, centrifuge, wash three times alternately with N,N-dimethylformamide and acetone, vacuum dry at 80℃ for 12-24h, and irradiate under ultraviolet light for 1-2h to obtain liquid crystal elastomer / lead zirconate titanate core-shell material.

2. The impact-resistant insulating busbar according to claim 1, characterized in that: The terminal amino polyether has a functionality of 2 and a number-average molecular weight of 1800-2200. The mass ratio of maleic anhydride-grafted polyolefin elastomer, 2-furan methylamine, amino-terminated polyether, and p-toluenesulfonic acid is 100:(0.05-0.5):(4.1-10.2):(0.1-0.55).

3. The impact-resistant insulating busbar according to claim 1, characterized in that: The bismaleimide crosslinking agent is 1,1'-(methylenedi-4,1-phenylene)bismaleimide.

4. The impact-resistant insulating busbar according to claim 1, characterized in that: In step A1, the ratio of maleic anhydride-grafted ethylene-vinyl acetate copolymer, deionized water, N,N-dimethylformamide, N-hydroxysuccinimide, and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride is 10g:0.36g:200mL:0.6g:1.15g; in step A2, the ratio of dopamine hydrochloride, triethylamine, and N,N-dimethylformamide in the N,N-dimethylformamide mixed solution containing dopamine hydrochloride and triethylamine is 0.5g:

0. 0.35g:10mL; In step A2, the volume ratio of the N,N-dimethylformamide mixed solution to the reaction system solution is 1:20; In step A2, the volume ratio of diethyl ether to n-hexane in the mixed solvent is (1-2):(1-2); In step A2, the volume ratio of the reaction solution to the mixed solvent is 1:(8-12); In step A3, the ratio of catechol-modified EVA, tetrahydrofuran, 1,4-phenylenediboric acid and methanol is 5g:50mL:0.18g:1.5g.

5. The impact-resistant insulating busbar according to claim 1, characterized in that: In step B1, the particle size of the nano-lead zirconate titanate particles is 100-200 nm; the volume ratio of ethanol to deionized water in the ethanol solution is 19:1; and the volume ratio of the nano-lead zirconate titanate particles to the ethanol solution is 1 g:(40-60) mL.

6. The impact-resistant insulating busbar according to claim 1, characterized in that: In step B2, the diacrylate monomer containing the liquid crystal unit is either 1,4-bis-[4-(3-acryloyloxypropoxy)benzoyloxy]-2-methylbenzene or 1,4-bis-[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-methylbenzene; the ratio of the amount of KH-570 modified PZT particles, N,N-dimethylformamide, pentaerythritol tetrakis(3-mercaptopropionic acid) ester chain transfer agent, azobisisobutyronitrile free radical initiator and the diacrylate monomer containing the liquid crystal unit is 1g:20mL:0.2g:0.02g:2g.

7. The impact-resistant insulating busbar according to claim 1, characterized in that: The antioxidant is any one or more of antioxidant 1010, antioxidant 168, antioxidant 1076, antioxidant BHT, antioxidant DLTP, and antioxidant TNPP.

8. The impact-resistant insulating busbar according to claim 1, characterized in that: The voltage stabilizer is either pyromellitic diimide or N,N'-dimethyl-3,4,9,10-perylenetetracarboxylic diimide.

9. The method for preparing the impact-resistant insulating busbar according to any one of claims 1-8, characterized in that: The specific steps are as follows: S1. The substrate is degreased, sandblasted and roughened, cleaned and dried in sequence. It is then immersed in a solvent containing bifunctional group molecules at 50-60℃ for 0.5-1h. After being taken out and washed with the corresponding solvent, it is vacuum dried at 40℃ to obtain the motherboard with adhesive layer. The mass fraction of the bifunctional group molecule in the solvent is 1-3%; The solvent is any one or two of ethanol, propanol, isopropanol, butanone, acetone, toluene, and ethyl acetate; S2. Weigh the insulating layer raw materials according to the weight parts. Mix furan-functionalized polyolefin elastomer, catechol-boron ester modified EVA, liquid crystal elastomer / lead zirconate titanate core-shell material, hexagonal boron nitride nanosheets, polyethylene glycol-polystyrene-polyperfluorohexyl ethyl acrylate block copolymer, antioxidant, silane surface-modified aluminum hydroxide micro powder and voltage stabilizer in a mixer at 120-140℃ and 30r / min speed for 2-3min. Add 3,4-ethylenedioxythiophene, increase the speed to 60-80r / min and mix for 10-15min. Cool to 90-95℃, add bismaleimide crosslinking agent, mix well, sheet, cool and granulate to obtain insulating layer composite masterbatch. S3. Place the busbar with adhesive layer obtained in step S1 into a preheated mold, fill it with the composite masterbatch of insulating layer obtained in step S2, hot press it at a temperature of 170-180℃ and a pressure of 15-20MPa for 15-25 minutes, hold the pressure and cool it before demolding to obtain the impact-resistant insulating busbar.

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