Multi-synergistic enhanced polyurea elastomer material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of preparation of polyurea elastomer materials, in particular to a multi-synergistic enhanced polyurea elastomer material as well as a preparation method and application thereof. The material is prepared from a specific component A and a specific component B through a reaction, and a synergistic flame-retardant system, a multi-scale enhancement system and an intelligent protection system are innovatively integrated. A ceramic framework carbon layer is formed through 'phosphorus-nitrogen-silicon' synergy, step-by-step dissipation of stress is achieved through 'nanometer-micrometer' synergy, dynamic long-acting protection is provided through 'self-repairing-hydrophobic' synergy, and the problem that a traditional protection material is single in performance and restricts one another is solved. The preparation method adopts a unique nanometer pre-dispersion and multi-step charging process. Compared with the prior art, the material provided by the invention simultaneously has excellent fireproof and heat-insulating, impact-resistant, wear-resistant and self-repairing waterproof performances, and can fundamentally improve the safety and reliability of a battery pack and a chassis of a new energy automobile.

Description

Technical Field

[0001] This invention relates to the field of polyurea elastomer material preparation technology, specifically to multi-synergistic reinforced polyurea elastomer materials, their preparation methods, and applications. Background Technology

[0002] With the explosive growth of the global new energy vehicle (NEV) industry, the safety of power battery systems has become a core bottleneck restricting the industry's development and an absolute focus of consumer attention. As the energy center of the entire vehicle, the battery pack faces complex and ever-changing safety threats from multiple dimensions and extremes, including physical, thermal, and chemical factors, under complex and varied driving conditions.

[0003] When a vehicle is traveling at high speed, the chassis inevitably encounters the risk of violent impacts from road debris and foreign objects, scratches from sharp objects, and even punctures from accidental bottoming out. Once these physical damages affect the battery pack casing, they can easily cause internal cell deformation and short circuits, potentially triggering catastrophic thermal runaway. Whether caused by an external fire source or internal thermal runaway due to a single cell failure, the resulting high temperatures and flames will spread rapidly within the battery pack. Effectively blocking the spread of heat and flames in the early stages of thermal runaway, thus providing occupants with precious "golden escape time," is a critical challenge that current battery safety technology urgently needs to overcome. The battery pack and chassis are constantly exposed to corrosive environments such as humidity, salt spray, acid rain, and de-icing agents, while also enduring continuous vibration and temperature cycling. This necessitates that protective materials possess stable and reliable waterproof sealing and corrosion resistance throughout their entire lifespan.

[0004] To address these challenges, existing technological solutions have significant limitations: traditional physical protection solutions, such as adding metal or composite material skid plates, while providing some impact resistance, significantly increase vehicle weight, sacrifice driving range, and may cause secondary damage after deformation. Traditional functional coating solutions, such as PVC chassis armor, asphalt coatings, or ordinary polyurethane coatings, generally suffer from limited functionality and low performance. More importantly, they are subject to irreconcilable performance constraints: for example, simple filler blending to improve flame retardancy often significantly sacrifices the material's flexibility and impact resistance, leading to embrittlement and cracking; while formulations pursuing high flexibility typically lack sufficient hardness and wear resistance.

[0005] Therefore, there is an urgent need in this field for a protective material that is no longer a simple compromise or superposition of various performance indicators, but rather achieves a simultaneous leap and organic unity of multiple core properties such as flame retardancy, toughness, wear resistance, and long-lasting waterproofing through molecular-level design and deep synergy of multiple systems, so as to provide an integrated safety solution for new energy vehicles. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a multi-synergistic reinforced polyurea elastomer material that provides "firewall" level thermal protection and physical impact resistance, fundamentally improving the survivability of core components of new energy vehicles under extreme accidents.

[0007] Another objective of this invention is to provide a method for preparing a multi-synergistically reinforced polyurea elastomer material, which breaks through the design bottleneck of mutual constraints between the properties of traditional materials such as "flame retardancy / toughness / wear resistance", and achieves simultaneous enhancement and comprehensive improvement of all key safety indicators.

[0008] The third objective of this invention is to provide an application of a multi-synergistic reinforced polyurea elastomer material for the safety protection of battery pack housings, chassis, or high-voltage components in new energy vehicles.

[0009] This invention is achieved using the following technical solution: The aforementioned multi-synergistic reinforced polyurea elastomer material is prepared by reacting component A and component B, wherein the mass ratio of component A to component B is 1:(1.05-1.12). Component A is an isocyanate prepolymer with an NCO content between 14.5% and 16.5%. Component B is a mixture of composite functional amines, comprising 100 parts by weight of the main resin and amine chain extender, and includes: a. A phosphorus-nitrogen-silicon synergistic flame retardant system, wherein the dosage is 23.5-68 parts; b. A nano-micro multi-scale reinforcement system, wherein the dosage is 5.7-30 parts; c. An intelligent protection system, the dosage of which is 8-30 parts; d. An adjuvant, used in amounts of 3-12 parts.

[0010] Component A has an NCO content between 14.5% and 16.5%. When the NCO content is within this range, it reacts with the amine groups of component B to form an ideal ratio of hard and soft segments. If the NCO content is below 14.5%, the hard segment content will be insufficient, resulting in a decrease in the hardness, strength, and wear resistance of the polyurea elastomer. If the NCO content is above 16.5%, the hard segment content will be too high, making the material too hard and brittle, significantly reducing the elongation at break and impact resistance, and failing to meet the toughness required for chassis protection. Component A is prepared by reacting aromatic isocyanate (diphenylmethane diisocyanate, MDI) with polyether polyol. To improve processability, liquefied MDI or modified MDI is preferred to reduce the viscosity of the prepolymer at room temperature, facilitating storage and transportation.

[0011] Traditional flame-retardant polymers rely on forming a loose, fragile char layer. This invention overturns this model through a quaternary synergy of phosphorus (P), nitrogen (N), silicon (Si), and carbon (C). The principle lies in the "in-situ self-generated ceramic-framework-reinforced expanded char layer": Upon heating, APP-II decomposes to produce polyphosphoric acid, which acts as a strong dehydrating agent and acid catalyst, promoting efficient dehydration and crosslinking of phytic acid and the polyurea matrix in PA-MMT, forming the basic expanded char layer (C-source). Simultaneously, the nano-montmorillonite (Si-source) sheets in PA-MMT act as high-temperature resistant "bricks," forming an initial physical barrier within the char layer. The non-combustible gases such as NH3 and N2 released by APP-II and MCA (N-source) dilute the oxygen concentration in the gas phase and purge and cool the flame; simultaneously, these gases cause the molten polymer matrix to foam, forming a porous structure and reducing the thermal conductivity of the char layer. More importantly, phosphates react with nitrogen-containing compounds at high temperatures to form a highly thermally stable PN cross-linked structure (phosphorus-oxygen-nitrogen compounds), which fundamentally improves the heat resistance and oxidation resistance of the carbon layer skeleton. At even higher temperatures, polyphosphoric acid reacts with the hydroxyl or siloxane bonds on the surface of montmorillonite to generate inorganic phosphorus-silicate or phosphorus-oxygen-silicon ceramic phases in situ. These ceramic phases are uniformly distributed at the nanoscale and anchored in the PN cross-linked carbon skeleton, much like introducing high-strength ceramic reinforcement into concrete. This completely changes the physical properties of the carbon layer: from the "loose and brittle" nature of traditional organic carbon to a "dense and tough" organic-inorganic hybrid ceramic body. This ceramic skeleton greatly inhibits the shrinkage and cracking of the carbon layer, enabling it to maintain structural integrity under prolonged flame erosion. As a result, the thermal insulation performance increases exponentially, achieving a qualitative leap from "flame retardant" to "fireproof and heat-insulating wall".

[0012] The phosphorus-nitrogen-silicon synergistic flame retardant system comprises: 14-36 parts of ammonium polyphosphate, 7-20 parts of phosphorus-modified layered silicate, and 2.5-12 parts of nitrogen-based flame retardant.

[0013] The phosphorus-modified layered silicate is phytic acid-modified montmorillonite.

[0014] The phosphorus-nitrogen-silicon synergistic flame retardant system preferably consists of "ammonium polyphosphate (APP)," "phosphorus-containing modified layered silicate," and "nitrogen-based flame retardant." In a preferred embodiment, it specifically comprises "APP-II," "phytic acid-modified montmorillonite (PA-MMT)," and "melamine cyanurate (MCA)." The dosage of APP-II ranges from 10 to 18 parts. Below 10 parts, the flame retardant effect is acceptable, but the limiting oxygen index is low; above 18 parts, the mechanical properties are sacrificed due to excessive filler content. The dosage of PA-MMT ranges from 5 to 10 parts. It is key to achieving "P-Si synergy" in forming a high-strength ceramic-like carbon layer. Below 5 parts, the carbon layer strength is insufficient; above 10 parts, excessive nanosheets may affect the material's flowability and elongation. The dosage of MCA ranges from 2 to 6 parts. It provides gas-phase synergy and forms a PN synergy with APP.

[0015] The nano-micro multi-scale reinforcement system comprises: 0.7-6 parts of carbon-based nanomaterials, 2.5-12 parts of high-toughness microfibers, and 2.5-12 parts of high-hardness nanoparticles.

[0016] The carbon-based nanomaterials are functionalized graphene oxide (f-GO), the high-toughness microfibers are aramid fibers, and the high-hardness nanoparticles are nano-silicon carbide (Nano-SiC). The f-GO dosage ranges from 0.5 to 3 parts. As a "nanorhine," dispersion is crucial. Below 0.5 parts, the interface reinforcement effect is not significant; above 3 parts, agglomeration easily occurs, becoming a defect. The aramid fiber dosage ranges from 2 to 6 parts. It is the main force resisting macroscopic punctures and tears. Without aramid, the material's impact resistance drops sharply, and the elongation at break decreases significantly, making the material brittle. The Nano-SiC dosage ranges from 2 to 6 parts. It is the core component for improving wear resistance. Without SiC, wear and scratch resistance decreases significantly.

[0017] Traditional reinforcement methods often compromise on one aspect while achieving another, making it difficult to simultaneously achieve both hardness and toughness. This invention constructs a "nano-micro" cross-scale reinforcement network, achieving orderly stress transfer and progressive dissipation across different scales: amino-functionalized graphene oxide (f-GO) acts like countless "nanoromandibular rivets," whose two-dimensional sheet structure and surface functional groups simultaneously form strong chemical or hydrogen bonds with the polyurea matrix and aramid fibers, firmly locking the originally weak filler-matrix interface and preventing interface debonding during impact. This is the foundation for the synergistic operation of the entire reinforcement system. When microcracks attempt to propagate, they encounter high-modulus f-GO sheets and high-hardness Nano-SiC particles. These nanoparticles force crack paths to deflect, branch, and even form micro-regional plastic deformation around the nanoparticles, thereby dissipating a large amount of energy and significantly improving the material's fracture toughness and crack initiation threshold. When the impact energy is enormous and microcracks converge into macrocracks, the aramid fibers embedded in the matrix begin to act as "steel reinforcement." Cracks propagate to the fibers, requiring high-energy-consuming processes such as fiber pull-out, fiber breakage, or fiber bridging to continue. The fiber pull-out process, in particular, involves significant interfacial friction work, absorbing most of the impact energy and preventing catastrophic penetration damage. The essence of this invention lies in the fact that the nano-reinforcement does not work independently. The strong interfacial network constructed by f-GO allows impact stress to be efficiently transferred from the polyurea matrix to the high-toughness aramid fibers, activating the full potential of the aramid fibers. Without this efficient "stress transfer chain," aramid fibers could easily be pulled out directly from the weak interface when stress is insufficient, failing to achieve their maximum energy absorption effect. Therefore, the "rivet" effect of f-GO and the "rib" effect of aramid are interdependent, synergistically achieving an overall strengthening and toughening effect.

[0018] The intelligent protection system comprises 5.5-20 parts of a diamine containing reversible dynamic chemical bonds and 2.5-10 parts of a functional amine containing fluorinated silane groups. The value of the intelligent system lies in its "dynamic" and "long-lasting" properties. Minor damage can self-repair, allowing its superhydrophobic surface to recover even after scratches, thus maintaining a high level of waterproof and corrosion-resistant capabilities for a long time—a feature not found in traditional coatings.

[0019] Traditional protection is passive and static. This invention, by introducing dynamic chemical bonds and low surface energy molecules, endows materials with the ability to actively adapt and self-heal: the introduced disulfide-bonded diamine forms reversible dynamic cross-linking points in the polyurea network. When the material is subjected to external forces and microcracks are generated, these stress-concentrated disulfide bonds preferentially break, absorbing energy and preventing the cracks from evolving into catastrophic fracture. After the external force is removed, these broken sulfur free radicals, or through exchange reactions, can re-bond under room temperature or microthermal conditions, thereby "healing" the microcracks and restoring the mechanical integrity and airtightness of the material. The superhydrophobicity of the coating depends on the low surface energy material (fluorosilicone segments) and micro-rough structure of the surface. When the surface is scratched and damaged, the water resistance decreases. The synergy of this invention lies in the fact that the self-healing process is not only structural repair but also functional repair. When the microcracks heal, the movement of polymer segments causes the "reserved" fluorosilane groups inside the system to migrate back to the newly exposed surface, rebuilding the low surface energy interface to a certain extent and achieving partial or complete restoration of hydrophobicity. This is an intelligent closed loop of "damage-response-repair-functional regeneration", which ensures that the coating can maintain a high level of waterproof and corrosion resistance throughout the entire service life, achieving a leap from "static waterproofing" to "dynamic long-term sealing".

[0020] The main resin is an amino-terminated polyether, and the amine chain extender is an aromatic diamine chain extender; the additives consist of silane coupling agents, dispersants, defoamers, and pigments.

[0021] The host resin mainly refers to high molecular weight terminal amino compounds, which react with isocyanates to form "soft segments" in polyurea, giving the material excellent flexibility, elasticity, and low-temperature performance. The molecular weight of the host resin is typically between 1000 and 5000 g / mol. The host resin chain is a terminal amino polyether, which can be one or a mixture of difunctional terminal amino polyoxypropylene glycol ethers or trifunctional terminal amino polyoxypropylene triol ethers. Using a mixture of both can introduce appropriate crosslinking while ensuring flexibility, thereby improving the strength and resilience of the material.

[0022] The amine chain extenders mainly refer to low molecular weight diamines or polyamine compounds. Their function is to react rapidly with isocyanates to form "hard segments" in polyurea, imparting high strength, high modulus, high hardness, and heat resistance to the material. The amine chain extenders are aromatic diamine chain extenders because they have moderate reactivity and can form high-strength rigid hard segments. Diethyltoluene diamine (DETDA) is preferred because it is a liquid, easy to handle, reacts quickly, and imparts excellent physical properties to the material.

[0023] The preparation method of the aforementioned multi-synergistic reinforced polyurea elastomer material includes the following steps: (1) Nano pre-dispersion step: The nanomaterials in the nano-micro multi-scale reinforcement system are mixed with a portion of the main resin, and ultrasonic dispersion treatment with a power of not less than 600W is performed under the condition that the material temperature is lower than 50℃, or high-energy ball milling treatment is performed to prepare nano composite masterbatch. (2) Composite slurry preparation steps: Mix the nanocomposite masterbatch with the remaining main resin, then add the powder raw material of the phosphorus-nitrogen-silicon synergistic flame retardant system and the micron fiber in the nano-micron multi-scale reinforcement system, and perform high-speed shear dispersion at a speed of 1500-2500 rpm until the slurry fineness is no greater than 60 μm; (3) Functional blending step: After cooling the slurry obtained in step (2) to below 45°C, add the amine chain extender and the liquid raw material and additives of the intelligent protection system in sequence, and stir at low speed at 300-500 rpm to mix evenly. (4) Degassing step: The final mixture obtained in step (3) is subjected to vacuum degassing treatment under a vacuum degree of not less than -0.09MPa.

[0024] Specifically, raw material pretreatment: Liquid raw material pretreatment (terminated amine polyether, self-healing amine, hydrophobic amine, etc.): Place the liquid raw material in a reactor equipped with a stirrer and a vacuum interface. Heat to 105-110℃ with stirring, turn on the vacuum pump, and dehydrate for 1-2 hours under a vacuum degree ≤100Pa until no bubbles escape. After cooling to room temperature, break the vacuum with dry nitrogen and seal for later use.

[0025] Powder raw material pretreatment (APP-II, PA-MMT, MCA, Nano-SiC, carbon black, etc.): Place the powder raw material in a forced-air drying oven and bake at 110-120℃ for 4-6 hours. After removal, cool to room temperature in a desiccator for later use.

[0026] Fiber raw material pretreatment (aramid staple fiber): dry in a vacuum oven at 80℃ for 4 hours, or vacuum dry at room temperature for 8 hours.

[0027] Detailed preparation steps for component B: Step 1: Preparation of Nano-Reinforced Masterbatch; Add the prescribed amounts of f-GO and Nano-SiC to approximately 20%-30% of the total formulated amount of terminal amino polyether, and perform high-energy dispersion. Dispersion method: ultrasonic dispersion or high-energy ball milling. Ultrasonic power: 600W-1000W. Dispersion time: 20-40 minutes. Temperature control: Strictly control the material temperature below 50℃ through cooling jacket or intermittent operation.

[0028] Step 2: Composite slurry dispersion; In a high-speed dispersion vessel, mix the remaining main resin with the nano-masterbatch obtained in Step 1 until homogeneous, then start high-speed shearing and add all powder raw materials (flame retardant system, fibers, etc.) sequentially. High-speed shearing speed: 1500-2500 rpm. Powder dispersion time: 30-60 minutes. Dispersion endpoint criterion: Using a scraper fineness gauge, the slurry fineness should not exceed 60 μm.

[0029] Step 3: Functional liquid blending; After cooling the dispersed slurry, add all remaining liquid amine raw materials and additives sequentially while stirring at low speed. Target cooling temperature: below 45℃. Low-speed stirring speed: 300-500 rpm.

[0030] Step 4: Vacuum Degassing and Encapsulation; The final mixture is vacuum degassed to remove air introduced during processing. Vacuum level: not less than -0.09 MPa. Degassing time: 10-30 minutes, or until no obvious bubbles escape.

[0031] The aforementioned multi-synergistic reinforced polyurea elastomer material is used for the safety protection of battery pack housings, chassis, or high-voltage components in new energy vehicles.

[0032] The aforementioned safety protection involves applying a protective coating made of the polyurea elastomer material to the surface of the battery pack casing, chassis, or high-voltage components. The thickness of the protective coating is 2.0-3.0 mm.

[0033] Compared with the prior art, the beneficial effects of the present invention are: (1) Ultimate Safety: It provides "firewall" level thermal protection and physical impact resistance, fundamentally improving the survivability of core components of new energy vehicles under extreme accidents. It has micro-damage self-healing properties, can resist daily scratches and long-term environmental corrosion, and ensures stable protection throughout the entire life cycle.

[0034] (2) It completely breaks through the design bottleneck of mutual constraints between the traditional materials' properties such as "flame retardancy / toughness / wear resistance", and achieves simultaneous enhancement and comprehensive improvement of all key safety indicators. The solvent-free spraying process is adopted, which has high production efficiency and is environmentally friendly, and is fully adapted to the fast-paced and green requirements of modern automobile manufacturing. Detailed Implementation

[0035] To make the objectives and technical solutions of this invention clearer, the invention will be further described in detail below.

[0036] Liquefied MDI: Wannate® PM-200, a commercially available product of Wanhua Chemical Group Co., Ltd. Polyether polyols (PPG): PPG-2000, VORANOL 220-110, commercially available products from Dow Chemical Company, USA; Amino-terminated polyethers: JEFFAMINE® D-2000, T-5000, commercially available products from Huntsman Corporation, USA; Diethyltoluenediamine (DETDA): Ethacure® 100, a commercially available product from Albemarle, Inc., USA; Ammonium polyphosphate: Exolit® AP422 (APP-II), a commercially available product from Clariant, Switzerland; Melamine cyanurate (MCA), industrial grade, a commercially available product of Shandong Shiyin New Material Technology Co., Ltd. Functionalized graphene oxide (f-GO): SE2430-N (amino-functionalized), a commercially available product from Changzhou Sixth Element Materials Technology Co., Ltd. Aramid staple fiber: Twaron® 1099 (6mm), a commercially available product of Teijin, Netherlands; Nano-silicon carbide: β-SiC, particle size 50nm, commercially available product of Shanghai Yaotian New Materials Technology Co., Ltd. Inert filler: Talc powder, 1250 mesh, commercially available product from Guangxi Guihua Talc Co., Ltd. Silane coupling agent: KH-560, a commercially available product from Nanjing Shuguang Silane Chemical Co., Ltd. Dispersant: BYK-111, a commercially available product from BYK Chemical AG, Germany; Defoamer: BYK-052, a commercially available product from BYK Chemical AG, Germany; Pigment: Carbon black, Printex® U, a commercially available product of Evonik Industries, Germany; Sodium-based montmorillonite (Na-MMT): Nanomer® PGV, a commercially available product from Nanomer Inc., USA; Phytic acid solution: 50wt% aqueous solution, analytical grade (AR), commercially available product from Shanghai Maclean Biochemical Technology Co., Ltd. Cystamine dihydrochloride: Purity >98%, commercially available product of Shanghai Aladdin Biochemical Technology Co., Ltd.; Epichlorohydrin (ECH): Purity >99%, commercially available product from Dow Chemical Company, USA; JEFFAMINE® D-400: Polyetheramine, a commercially available product from Huntsman Corporation, USA; (3-Glycidyl etheroxypropyl)methyldiethoxysilane: KBE-402, a commercially available product of Shin-Etsu Chemical Co., Ltd., Japan; Nonafluorohexyltriethoxysilane: 1H,1H,2H,2H-Perfluorohexyltriethoxysilane, purity >97%, commercially available product from Harbin Fluorine Source Chemical Co., Ltd.

[0037] The preparation method of phytic acid modified montmorillonite (PA-MMT) is as follows: Weigh 100g of sodium-based montmorillonite (Na-MMT, cation exchange capacity CEC≈90meq / 100g), disperse it in 2L of deionized water, and stir at high speed for 24 hours to allow it to fully swell and disperse, forming a homogeneous suspension. Let it stand for 48 hours, and take the upper layer of approximately 80% of the suspension. While stirring, slowly add 1M hydrochloric acid solution dropwise to the upper layer of suspension to adjust the pH of the suspension to 3.0. Continue stirring for 4 hours. Weigh 60g of phytic acid solution (50%wt.) and dilute it with deionized water to 500mL. Slowly add the diluted phytic acid solution dropwise to the prepared acidified montmorillonite suspension while stirring vigorously. The molar amount of phytic acid far exceeds the CEC value of montmorillonite to ensure sufficient ion exchange and physical adsorption. Transfer the mixed suspension to a constant temperature water bath and react continuously at 60℃ for 12 hours with stirring. Cool the resulting suspension to room temperature, transfer it to a centrifuge tube, and centrifuge at 8000 rpm for 15 minutes. Discard the supernatant. Add deionized water back to the precipitate, sonicate for 10 minutes, and then centrifuge again. Repeat this wash-centrifugation process 5 times until the pH of the supernatant is close to neutral (approximately 6.5-7.0).

[0038] The washed precipitate (filter cake) is freeze-dried in a freeze dryer for 48 hours to obtain a loose, powdery product, preventing agglomeration during the drying process. If a freeze dryer is unavailable, the filter cake can be dried in a vacuum oven at 80°C for 24 hours. The dried lumpy product is then ground using a planetary ball mill or an agate mortar and pestle, and passed through a 200-mesh sieve to obtain a white phytic acid-modified montmorillonite (PA-MMT) powder.

[0039] The self-healing amine selected is disulfide diamine (DSDD), and its preparation method is as follows: In a 500 mL three-necked flask equipped with a condenser, dropping funnel, and thermometer, add 22.5 g (0.1 mol) of cystamine dihydrochloride and 200 mL of methanol. Stir until dissolved. Dissolve 37.0 g (0.4 mol, 4 times excess) of epichlorohydrin in 50 mL of methanol and place the solution in a constant-pressure dropping funnel. Place the three-necked flask in an ice-water bath and cool to 0–5 °C. While stirring vigorously, slowly add the epichlorohydrin solution dropwise, controlling the rate of addition to keep the reaction system temperature below 10 °C. The addition process takes approximately 1–2 hours. After the addition is complete, remove the ice bath and continue stirring the reaction system at room temperature (25 °C) for 24 hours. After the reaction is complete, cool the system again to 0–5 °C. Slowly add a 20% (w / w) aqueous solution of sodium hydroxide, carefully adjusting the pH to 10–11. This step aims to neutralize the cystamine hydrochloride and catalyze the ring closure of the chlorohydrin intermediate to form an epoxy group. After neutralization, continue stirring at room temperature for 4 hours. Remove most of the methanol from the reaction mixture using a rotary evaporator. Extract the remaining viscous mixture with 200 mL of ethyl acetate and 100 mL of saturated brine. Separate the organic phase; extract the aqueous phase twice more with 100 mL of ethyl acetate. Combine all organic phases and dry overnight with anhydrous magnesium sulfate. Filter to remove the drying agent, and evaporate the ethyl acetate from the filtrate using a rotary evaporator to obtain a pale yellow, viscous, oily liquid or semi-solid product. Dissolve the crude product in a minimal amount of hot ethanol, cool, and allow to crystallize in a refrigerator. Collect the crystals by filtration, wash with a small amount of cold ethanol, and dry under vacuum to obtain a high-purity disulfide diamine (DSDD) product.

[0040] The hydrophobic amine used is a fluorosilicone-modified polyether amine, and its preparation method is as follows: In a dry three-necked flask, add 31.2 g (0.1 mol) of nonafluorohexyltriethoxysilane and 24.8 g (0.1 mol) of (3-glycidyl etheroxypropyl)methyldiethoxysilane, along with 100 mL of anhydrous toluene. Add 2-3 drops of concentrated hydrochloric acid as a catalyst and a small amount of water (approximately 0.2 mL) to initiate hydrolysis. Heat the system to 80 °C and reflux under nitrogen protection for 8 hours to carry out the hydrolysis-condensation reaction. After the reaction is complete, remove toluene and the byproduct ethanol by rotary evaporator to obtain the fluorosiloxane-containing glycidyl ether intermediate (F-Si-Epoxy). In another dry three-necked flask, add 40.0 g (0.1 mol) of pre-vacuum-dehydrated JEFFAMINE® D-400 and 150 mL of anhydrous toluene. Dissolve all the F-Si-Epoxy intermediate obtained in step 1 in 50 mL of anhydrous toluene and transfer the solution to a dropping funnel. The three-necked flask was heated to 100°C. While stirring, an F-Si-Epoxy solution was slowly added dropwise. The amino group of JEFFAMINE® D-400 undergoes a ring-opening reaction with the epoxy group. After the addition was complete, the reaction was continued at 100°C for 12 hours to ensure complete reaction. After the reaction was complete, the mixture was cooled to room temperature. The solvent toluene was removed by rotary evaporation. The resulting viscous liquid product was subjected to thin-film distillation or vacuum distillation at 100°C and high vacuum (<10 Pa) to remove unreacted JEFFAMINE® D-400 and small molecule impurities. A clear, pale yellow viscous liquid was finally obtained, which is the target product, fluorosilicone-modified polyetheramine.

[0041] The preparation method of component A prepolymer is as follows: In a reactor equipped with a stirrer, thermometer, and nitrogen protection, a measured amount of polyether polyol (PPG, molecular weight 2000 g / mol) is added, and the mixture is heated to 110℃ for dehydration for 1 hour. After cooling to 50℃, liquefied MDI is slowly added dropwise under stirring, controlling the temperature to not exceed 80℃. After the addition is complete, the reaction is maintained at 78℃ for 3 hours. Samples are taken periodically, and the -NCO content is determined using the di-n-butylamine titration method (GB / T12009.5) until the target value is reached. The mixture is then cooled, a stabilizer is added, and the product is discharged and sealed for storage. The proportions and test results of each raw material in component A prepolymer are shown in Table 1.

[0042] The 'additives' described in all examples and comparative examples are composed of the following components in the following weight ratio: silane coupling agent (KH-560): dispersant (BYK-111): defoamer (BYK-052): pigment (carbon black) = 1.5:1:0.5:1.5.

[0043] Test method: Tensile strength: GB / T528-2009; Elongation at break: GB / T528-2009; Impact strength: GB / T1732-1993; Adhesion (pull-off test): GB / T5210-2006; Abrasion resistance (Taber method): GB / T1768-2006; Flame retardancy (vertical burning method): GB / T2408-2008; Water contact angle: Using a contact angle meter, drop 5 μL of deionized water onto the horizontally placed coating surface.

[0044] After the water droplet stabilizes (approximately 5 seconds), the droplet profile is captured using the instrument software, and the static contact angles on the left and right sides are calculated and averaged. Five different locations are tested in each group, and the final average value is taken.

[0045] Self-repair efficiency: Cut a standard stretching specimen and use a sharp blade to make a cut at its center that is perpendicular to the stretching direction and about 50% of the specimen thickness.

[0046] Immediately test the tensile strength (original damage strength) of a portion of the scratched specimen.

[0047] The remaining scratched specimens were placed in a constant temperature oven at 60℃ and heat-treated for 2 hours.

[0048] After being removed and cooled to room temperature, the tensile strength of the repaired specimen was tested.

[0049] Self-healing efficiency (%) = (Repaired strength - Original damage strength) / (Unscratched spline strength - Original damage strength) × 100%.

[0050] Raw material pretreatment: Liquid raw material pretreatment (terminated amine polyether, self-healing amine, hydrophobic amine, etc.): Place the liquid raw material in a reactor equipped with a stirrer and a vacuum interface. Heat to 108°C with stirring, turn on the vacuum pump, and dehydrate under a vacuum of 100 Pa for 2 hours until no bubbles escape. After cooling to room temperature, break the vacuum with dry nitrogen and seal for later use.

[0051] Powder raw material pretreatment (APP-II, PA-MMT, MCA, Nano-SiC, carbon black, etc.): Place the powder raw material in a forced-air drying oven and bake at 115℃ for 5 hours. After removal, cool to room temperature in a desiccator for later use.

[0052] Fiber raw material pretreatment (aramid staple fiber): dry in a vacuum oven at 80℃ for 4 hours, or vacuum dry at room temperature for 8 hours.

[0053] In this embodiment, the main resin is a mixture of difunctional JEFFAMINE® D-2000 and trifunctional JEFFAMINE® T-5000. JEFFAMINE® D-2000, as the main component for linear chain growth, provides excellent flexibility and elongation at break; while JEFFAMINE® T-5000 introduces crosslinking points, forming a three-dimensional network structure to improve the tensile strength, hardness, and resilience of the material. By adjusting the ratio of the two, the final mechanical properties of the polyurea material can be precisely controlled.

[0054] Example 1 Multiple synergistic reinforced polyurea elastomer materials, including: Component A is selected as an isocyanate prepolymer with an NCO content of 14.53%; the mass ratio of component A to component B is 1:1.1. Component B formulation (100 parts): JEFFAMINE® D-2000: 47 parts; JEFFAMINE® T-5000: 3 parts; DETDA: 20 parts; APP-II: 10 parts; PA-MMT: 5 parts; MCA: 2 parts; f-GO: 0.5 parts; Aramid: 2 parts; Nano-SiC: 2 parts; self-healing amine: 4 parts; hydrophobic amine: 2 parts; additives: 2.5 parts.

[0055] The preparation steps are as follows: Nano-predispersion: Take 10 parts of terminal amino polyether, add 0.5 parts of f-GO and 2 parts of Nano-SiC. Under cooling conditions, disperse using 600W ultrasonic waves for 20 minutes, with the material temperature controlled below 48℃, to obtain masterbatch.

[0056] Composite slurry dispersion: Mix the remaining 40 parts of amino-terminated polyether with the above masterbatch. Start high-speed dispersion at 1500 rpm, and add 10 parts of APP-II, 5 parts of PA-MMT, and 2 parts of MCA sequentially, dispersing for 20 minutes. Then reduce the speed to 800 rpm, add 2 parts of Aramid fiber, and continue dispersing for 10 minutes. The final fineness was measured to be 60 μm.

[0057] Functional blending: Cool the slurry to 45°C. While stirring at a low speed of 400 rpm, add 4 parts of self-healing amine, 2 parts of hydrophobic amine, 20 parts of DETDA and 2.5 parts of additives in sequence, and mix for 15 minutes.

[0058] Degassing: Degas for 10 minutes under a vacuum of -0.09 MPa to obtain the product.

[0059] Example 2 Multiple synergistic reinforced polyurea elastomer materials, including: Component A is selected as an isocyanate prepolymer with an NCO content of 15.52%; the mass ratio of component A to component B is 1:1.09. Component B formulation (100 parts): JEFFAMINE® D-2000: 33 parts; JEFFAMINE® T-5000: 7 parts; DETDA: 18 parts; APP-II: 18 parts; PA-MMT: 10 parts; MCA: 6 parts; f-GO: 1 part; Aramid: 4 parts; Nano-SiC: 4 parts; Self-healing amine: 4 parts; Hydrophobic amine: 2 parts; Additives: 3 parts.

[0060] The preparation steps are as follows: Nano-predispersion: Take 10 parts of terminal amino polyether, add 1 part of f-GO and 4 parts of Nano-SiC. Under cooling conditions, disperse using 800W ultrasonic waves for 30 minutes, with the material temperature controlled below 45℃, to obtain masterbatch.

[0061] Composite slurry dispersion: Mix the remaining 30 parts of amino-terminated polyether with the above masterbatch. Start high-speed dispersion at 2000 rpm, and add 18 parts of APP-II, 10 parts of PA-MMT, and 6 parts of MCA sequentially, dispersing for 25 minutes. Then reduce the speed to 1000 rpm, add 4 parts of Aramid fiber, and continue dispersing for 15 minutes. The final fineness was measured to be 55 μm.

[0062] Functional blending: Cool the slurry to 40°C. While stirring at a low speed of 400 rpm, add 4 parts of self-healing amine, 2 parts of hydrophobic amine, 18 parts of DETDA and 3 parts of additives in sequence, and mix for 20 minutes.

[0063] Degassing: Degas for 20 minutes under a vacuum of -0.095 MPa to obtain the product.

[0064] Example 3 Multiple synergistic reinforced polyurea elastomer materials, including: Component A is selected as an isocyanate prepolymer with an NCO content of 15.52%; the mass ratio of component A to component B is 1:1.08. Component B formulation (100 parts): JEFFAMINE® D-2000: 36 parts; JEFFAMINE® T-5000: 5 parts; DETDA: 18 parts; APP-II: 14 parts; PA-MMT: 8 parts; MCA: 4 parts; f-GO: 1.5 parts; Aramid: 4 parts; Nano-SiC: 4 parts; self-healing amine: 7 parts; hydrophobic amine: 3.5 parts; additives: 4 parts.

[0065] The preparation steps are as follows: Nano-predispersion: Take 10 parts of terminal amino polyether, add 1.5 parts of f-GO and 4 parts of Nano-SiC. Under cooling conditions, disperse using 800W ultrasonic waves for 30 minutes, with the material temperature controlled below 45℃, to obtain masterbatch.

[0066] Composite slurry dispersion: Mix the remaining 30 parts of amino-terminated polyether with the above masterbatch. Start high-speed dispersion at 2000 rpm, and add 14 parts of APP-II, 8 parts of PA-MMT, and 4 parts of MCA sequentially, dispersing for 20 minutes. Then reduce the speed to 1000 rpm, add 4 parts of Aramid fiber, and continue dispersing for 15 minutes. The final fineness was measured to be 55 μm.

[0067] Functional blending: Cool the slurry to 45°C. While stirring at a low speed of 400 rpm, add 7 parts of self-healing amine, 3.5 parts of hydrophobic amine, 18 parts of DETDA and 4 parts of additives in sequence, and mix for 15 minutes.

[0068] Degassing: Degas for 20 minutes under a vacuum of -0.095 MPa to obtain the product.

[0069] Example 4 Multiple synergistic reinforced polyurea elastomer materials, including: Component A is selected as an isocyanate prepolymer with an NCO content of 14.53%; the mass ratio of component A to component B is 1:1.1. Component B formulation (100 parts): JEFFAMINE® D-2000: 38 parts; JEFFAMINE® T-5000: 2 parts; DETDA: 16 parts; APP-II: 10 parts; PA-MMT: 5 parts; MCA: 2 parts; f-GO: 0.5 parts; Aramid: 2 parts; Nano-SiC: 2 parts; self-healing amine: 10 parts; hydrophobic amine: 5 parts; additives: 7.5 parts.

[0070] The preparation steps are as follows: Nano-predispersion: Take 10 parts of terminal amino polyether, add 0.5 parts of f-GO and 2 parts of Nano-SiC. Under cooling conditions, disperse using 600W ultrasonic waves for 20 minutes, with the material temperature controlled below 48℃, to obtain masterbatch.

[0071] Composite slurry dispersion: Mix the remaining 30 parts of amino-terminated polyether with the above masterbatch. Start high-speed dispersion at 1500 rpm, and add 10 parts of APP-II, 5 parts of PA-MMT, and 2 parts of MCA sequentially, dispersing for 20 minutes. Then reduce the speed to 800 rpm, add 2 parts of Aramid fiber, and continue dispersing for 10 minutes. The final fineness was measured to be 60 μm.

[0072] Functional blending: Cool the slurry to 45°C. While stirring at a low speed of 400 rpm, add 10 parts of self-healing amine, 5 parts of hydrophobic amine, 16 parts of DETDA and 7.5 parts of additives in sequence, and mix for 25 minutes.

[0073] Degassing: Degas for 20 minutes under a vacuum of -0.095 MPa to obtain the product.

[0074] Example 5 Multiple synergistic reinforced polyurea elastomer materials, including: Component A is selected as an isocyanate prepolymer with an NCO content of 16.48%; the mass ratio of component A to component B is 1:1.06. Component B formulation (100 parts): JEFFAMINE® D-2000: 26 parts; JEFFAMINE® T-5000: 9 parts; DETDA: 15 parts; APP-II: 18 parts; PA-MMT: 10 parts; MCA: 6 parts; f-GO: 3 parts; Aramid: 6 parts; Nano-SiC: 6 parts; Self-healing amine: 10 parts; Hydrophobic amine: 5 parts; Additives: 6 parts.

[0075] The preparation steps are as follows: Nano-predispersion: Take 10 parts of terminal amino polyether, add 3 parts of f-GO and 6 parts of Nano-SiC. Under cooling conditions, disperse using 1000W ultrasonic waves for 40 minutes, with the material temperature controlled below 45℃, to obtain masterbatch.

[0076] Composite slurry dispersion: Mix the remaining 25 parts of amino-terminated polyether with the above masterbatch. Start high-speed dispersion at 2500 rpm, and add 18 parts of APP-II, 10 parts of PA-MMT, and 6 parts of MCA sequentially, dispersing for 30 minutes. Then reduce the speed to 1200 rpm, add 6 parts of Aramid fiber, and continue dispersing for 20 minutes. The final fineness was measured to be 50 μm.

[0077] Functional blending: Cool the slurry to 38°C. While stirring at a low speed of 500 rpm, add 10 parts of self-healing amine, 5 parts of hydrophobic amine, 15 parts of DETDA and 6 parts of additives in sequence, and mix for 25 minutes.

[0078] Degassing: Degas for 30 minutes under a vacuum of -0.098 MPa to obtain the product.

[0079] Comparative Example 1 The difference from Example 3 is that APP-II, PA-MMT, and MCA are not added; instead, 26 parts of inert talc are added.

[0080] Comparative Example 2 The difference from Example 3 is that PA-MMT and MCA are not added, and the amount of APP-II is increased to 26 parts.

[0081] Comparative Example 3 The difference from Example 3 is that f-GO is not added, and the amount of Aramid fiber is increased to 5.5 parts to maintain the total amount of filler.

[0082] Comparative Example 4 The difference from Example 3 is that Aramid fibers are not added, and the amount of f-GO is increased to 5.5 parts to maintain the total amount of filler.

[0083] Comparative Example 5 The difference from Example 3 is that Nano-SiC is not added, and 4 parts of talc are used instead to maintain the total amount of filler.

[0084] Comparative Example 6 The difference from Example 3 is that f-GO, Aramid, and Nano-SiC are not added; instead, 9.5 parts of talc are added.

[0085] Comparative Example 7 The difference from Example 3 is that no self-healing amine is added. In order to maintain the basic balance of amine equivalent, the amount of main resin is increased by 7 parts, namely JEFFAMINE® D-2000: 42 parts and JEFFAMINE® T-5000: 6 parts.

[0086] Comparative Example 8 The difference from Example 3 is that hydrophobic amines are not added, and the amount of main resin is increased by 3.5 parts, namely JEFFAMINE® D-2000: 39 parts; JEFFAMINE® T-5000: 5.5 parts.

[0087] Comparative Example 9 The difference from Example 3 is that self-healing amine and hydrophobic amine are not added, and the amount of terminal amino polyether is increased to 52.5 parts.

[0088] Comparative Example 10 The difference from Example 3 is that component B is simply prepared by mixing 70 parts JEFFAMINE® D-2000, 25 parts DETDA, and 5 parts additives.

[0089] Comparative Example 11 The difference from Example 3 is that all raw materials are added to the high-speed dispersion vessel at once and degasted after being dispersed at 2000 rpm for 60 minutes.

[0090] Comparative Example 12 The difference from Example 3 is that f-GO and Nano-SiC are directly added and dispersed together with other powders in step two.

[0091] Comparative Example 13 The difference from Example 3 is that an isocyanate prepolymer with an NCO content of 17.55% was used for spraying.

[0092] Comparative Example 14 The difference from Example 3 is that an isocyanate prepolymer with an NCO content of 13.48% was used for spraying.

[0093] Application Example 1 The polyurea material obtained in Example 3 was used as the raw material.

[0094] Sample preparation: Substrate: A 150mm×150mm×3mm 6061-T6 aluminum alloy plate was selected to simulate the battery pack casing material. The aluminum plate was sandblasted (Sa2.5 grade) and degreased with ethanol, then coated with a layer of epoxy zinc-rich primer (dry film thickness 50μm) and cured for 24 hours under standard conditions. The polyurea material obtained in Example 3 was sprayed onto the pretreated aluminum plate, with the final dry film thickness strictly controlled to 2.5±0.1mm. All samples were cured for 7 days at (23±2)℃ and (50±5)%RH.

[0095] Test setup: Fix the sample to be tested horizontally on the support, coating side down. At the geometric center of the sample's back (aluminum plate side), attach a K-type armored thermocouple probe using high-temperature thermally conductive adhesive, ensuring the probe is tightly fitted to the aluminum plate surface. Connect the thermocouple to a multi-channel temperature data logger, setting the sampling frequency to 1Hz (once per second). Directly below the sample, place a propane torch (flame temperature up to 1300℃) vertically, adjusting the torch height so that the tip of its blue flame is 50mm from the coating surface. Place fireproof baffles around the torch to reduce airflow disturbance.

[0096] Test Execution: Turn on the temperature recorder to record the initial back temperature. Ignite the blowtorch and immediately start the timer to ensure the flame continuously and stably burns the center point of the coating. Record the entire process on video, documenting macroscopic phenomena such as combustion, expansion, carbonization, dripping, and burn-through of the coating. Continuously record the temperature change curve on the back of the sample.

[0097] Flame penetration time: The time from the onset of burning to the first penetration of the coating and direct contact with the aluminum substrate by the flame. Determined through video playback and visual observation.

[0098] The thermal insulation failure time is the time from the start of burning to the temperature at the center point of the back of the sample reaching 250°C. 250°C is an important critical reference temperature for the propagation of thermal runaway in lithium batteries.

[0099] 10-minute back temperature: The temperature of the back of the sample 10 minutes after the start of burning.

[0100] Morphology of residual carbon layer: After the test, observe and record the thickness, density, strength and adhesion of the residual carbon layer to the substrate.

[0101] Application Example 2 The polyurea material obtained in Example 3 was used as the raw material.

[0102] Test method: Sample preparation: Q235 cold-rolled steel sheets measuring 100mm × 300mm × 1mm were selected and pre-coated with standard automotive-grade electrophoretic coating (EDCoat) to simulate a real vehicle chassis. The polyurea material obtained in Example 3 was sprayed onto the electrophoretic steel sheet, and the final dry film thickness was strictly controlled to be 2.5 ± 0.2mm. All samples were cured under standard conditions for 7 days.

[0103] Phase 1: Crushed stone impact test (refer to SAE J400 standard) Equipment: Gravelometer impact testing machine.

[0104] Test conditions: The sample was placed in a -20°C cryogenic chamber for 4 hours and tested immediately to simulate the brittleness of materials under low-temperature winter conditions. The frozen sample was fixed in the testing machine at a 45° angle. Using an air pressure of 80 psi (approximately 0.55 MPa), 1 pint (approximately 550 g) of standard gravel was sprayed onto the sample surface within 10 seconds. After the test, the sample was allowed to return to room temperature, and standard high-adhesion tape (3M 898) was firmly adhered to and quickly peeled off the impact area to remove all loose coating fragments. Based on the number and size of the chips in the impact area, a visual rating was performed according to the SAE J400 standard chart. The rating consists of a number (damage density) and a letter (damage size). The smaller the number and the earlier the letter appears, the better the impact resistance.

[0105] Neutral salt spray corrosion test (refer to ASTM B117 standard) Equipment: Neutral salt spray test chamber.

[0106] Procedure: The sample that had passed the first-stage impact test was suspended in a salt spray chamber at a 20° angle to the vertical. It was continuously sprayed with a 5% NaCl solution at 35°C for a total exposure time of 500 hours.

[0107] Corrosion rating: After 500 hours, remove the sample, gently rinse the surface with running warm water, and air dry. Evaluate the corrosion status using a method conforming to ASTM D1654. Corrosion spread width of the scratched or damaged area: Measured with calipers, this is the maximum single-sided distance from the edge of the original damage point outwards.

[0108] Overall Corrosion Rating (ASTM D610): Assess the percentage of red rust on the total area of ​​the sample and give a corresponding rating on a 10-point scale (10 = no rust, 0 = 100% rust).

[0109] Application Comparative Example 1 The difference from Application Example 1 is that the polyurea material obtained in Comparative Example 6 is used as the raw material.

[0110] Application Comparative Example 2 The difference from Application Example 2 is that the polyurea material obtained in Comparative Example 4 is used as the raw material.

[0111] The test data for Examples 1-5 are shown in Table 2.

[0112] The test data for comparative examples 1-14 are shown in Table 3.

[0113] The test data for Application Example 1 and Application Comparative Example 1 are shown in Table 4.

[0114] The test data for Application Example 2 and Application Comparative Example 2 are shown in Table 5.

[0115] Table 1: Proportions and Test Results of Raw Materials for Component A Prepolymer

[0116] Table 2: Test data for Examples 1-5

[0117] Table 3: Test data for comparative examples 1-14

[0118] As shown in Tables 2-3, all five embodiments performed perfectly in the most critical safety indicators—flame retardancy (V-0) and impact resistance (no cracking). This proves that the three synergistic systems constructed in this invention are stable, reliable, and effective. By adjusting the proportions of each component, performance can be tailored to specific areas. For example, Embodiments 2 and 5 exhibit higher strength and abrasion resistance when the content of reinforcing and flame-retardant components is higher; while Embodiment 4, with a higher content of intelligent protective components, possesses top-notch self-healing and hydrophobic properties. Embodiment 3 represents the optimal balance point for various performance aspects, representing the best combination of overall effectiveness and cost.

[0119] Comparative Example 1 was completely non-flame retardant, while Comparative Example 2, using a higher amount of a single flame retardant, was far less effective than Example 3. This irrefutably demonstrates the decisive role of the "phosphorus-nitrogen-silicon" synergy in forming a high-quality, high-strength char layer. Comparative Examples 3, 4, and 5 each removed a "component" from the reinforcing system, resulting in significant performance shortcomings: without f-GO, the interface weakened, leading to decreased impact resistance; without aramid, macroscopic toughness was lost, resulting in severe cracking under impact; and without SiC, wear resistance deteriorated drastically. Comparative Example 6, by completely removing the reinforcing system, almost completely collapsed its physical protection capability. This proves that nano-, micro-, and hard particles are indispensable, collectively forming a "joint defense" against damage at different scales. The results of Comparative Examples 7 and 8 are simple and direct: without self-healing amines, there is no self-healing function; without hydrophobic amines, there is no superhydrophobic surface. Comparative Example 9 simultaneously lost both of these "value-added" functions. This proves that the intelligent characteristics of this invention originate entirely from the introduction of specific functional molecules. Comparative Example 10 represents basic pure polyurea. Compared to Example 3, it shows orders of magnitude difference in all core safety protection indicators, including flame retardancy, impact resistance, abrasion resistance, and water resistance. This visually demonstrates the revolutionary progress of this invention compared to traditional technologies. Comparative Example 11 uses the most primitive one-step mixing method. Even with the correct formulation, the performance of the final product completely collapses, with a 33% decrease in strength, an 18% decrease in elongation, and a 2.6-fold difference in abrasion resistance, proving the absolute necessity of a multi-step dispersion process. Although Comparative Example 12 uses a multi-step method, it neglects the specialized pretreatment of nanomaterials, resulting in the nano-effects not being fully utilized, and its performance is still far inferior to Example 3. This proves that the refined preparation method including nano-pre-dispersion defined in this invention is the guarantee for achieving high performance. Comparative Examples 13 and 14 use the exact same component B as Example 3, except that the NCO content of component A deviates from the range defined in this invention. The results show that excessive NCO leads to an overly hard and brittle material that cracks upon impact; excessive NCO leads to an overly soft and weak material, resulting in a significant decrease in strength and abrasion resistance. These two failed cases "outside the boundary" powerfully demonstrate, from the opposite perspective, that the 14.5%-16.5% NCO content range proposed in this invention is the optimal window for achieving a balance between the rigidity and toughness of the material.

[0120] Table 4: Test data for Application Example 1 and Application Comparative Example 1

[0121] As shown in Table 4, although Comparative Example 1 has the exact same flame retardant formulation as Application Example 1, its heat insulation failure time and flame penetration time are less than half that of Application Example 1. The main reason is that it lacks reinforcing components such as f-GO and aramid fiber. The resulting expanded char layer loses its "steel skeleton," its mechanical strength decreases significantly, and it cannot withstand the physical erosion of the flame for a long time, leading to premature cracking and peeling, which causes the heat and flame to penetrate prematurely.

[0122] Table 5: Test data for Application Example 2 and Application Comparative Example 2

[0123] As shown in Table 5, Comparative Example 2 used a material formulation derived from Comparative Example 4, and its core deficiency lies in the lack of aramid fibers as a macroscopic reinforcing skeleton. Although its tensile strength is not low according to laboratory data, its elongation at break is significantly reduced, and the overall toughness of the material is insufficient. This performance shortcoming is drastically amplified in harsh low-temperature gravel impact applications: the impact resistance rating of Comparative Example 2 is far worse than that of Application Example 2, and the coating exhibits typical brittle tearing and peeling, losing complete protection for the underlying substrate. These impact-induced damage points then become the entry points for subsequent salt spray corrosion, resulting in a final corrosion resistance rating far lower than that of Application Example 2. This strongly demonstrates the integrity of the "nano-micro" multi-scale reinforcement system in this invention, especially the irreplaceable role of micron-level high-toughness fibers in resisting macroscopic physical damage and ensuring full life-cycle protective performance.

Claims

1. A multiple synergistically enhanced polyurea elastomer material, characterized by, Prepared by reacting A component and B component, wherein the mass ratio of A component to B component is 1: (1.05-1.12); The A component is an isocyanate prepolymer with an NCO content of 14.5%-16.5%; The B component is a composite functional amine mixture, which contains, based on 100 parts of the total weight of the main resin and amine chain extender: a. A phosphorus-nitrogen-silicon synergistic flame-retardant system in an amount of 23.5-68 parts; b. A nano-micro multi-scale reinforcing system in an amount of 5.7-30 parts; c. An intelligent protection system in an amount of 8-30 parts; d. An auxiliary agent in an amount of 3-12 parts.

2. The multiple synergistically enhanced polyurea elastomeric material of claim 1, wherein, The phosphorus-nitrogen-silicon synergistic flame-retardant system contains 14-36 parts of ammonium polyphosphate, 7-20 parts of phosphorus-containing modified layered silicate, and 2.5-12 parts of nitrogen-based flame retardant.

3. The multiple synergistically enhanced polyurea elastomeric material of claim 2, wherein, The phosphorus-containing modified layered silicate is phytic acid modified montmorillonite.

4. The multiple synergistically enhanced polyurea elastomeric material of claim 1, wherein, The nano-micro multi-scale reinforcing system contains 0.7-6 parts of carbon-based nanomaterial, 2.5-12 parts of high-toughness micro-fiber, and 2.5-12 parts of high-hardness nano-particles.

5. The multiple synergistically enhanced polyurea elastomeric material of claim 4, wherein, The carbon-based nanomaterial is functionalized graphene oxide, the high-toughness micro-fiber is aramid fiber, and the high-hardness nano-particles are nano-silicon carbide.

6. The multiple synergistically enhanced polyurea elastomeric material of claim 1, wherein, The intelligent protection system contains 5.5-20 parts of diamine containing reversible dynamic chemical bonds and 2.5-10 parts of functional amine containing fluorine-containing silane groups.

7. The multiple synergistically enhanced polyurea elastomeric material of claim 1, wherein, The main resin is an amino-terminated polyether, the amine chain extender is an aromatic diamine chain extender, and the auxiliary agent is composed of silane coupling agent, dispersant, defoamer, and pigment.

8. A process for the preparation of the multi-cooperative enhanced polyurea elastomer material according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: (1) Nano pre-dispersion step: mix the nanomaterial in the nano-micro multi-scale reinforcing system with a part of the main resin, and perform ultrasonic dispersion treatment at a power not less than 600W or high-energy ball milling treatment under the condition that the material temperature is lower than 50℃, to prepare a nano-composite master batch; (2) Composite slurry preparation step: mix the nano-composite master batch with the remaining main resin, then add the powder raw material of the phosphorus-nitrogen-silicon synergistic flame-retardant system and the micro-fiber in the nano-micro multi-scale reinforcing system, and perform high-speed shearing dispersion under the condition that the rotation speed is 1500-2500 rpm until the slurry fineness is not greater than 60μm; (3) Functional blending step: after the slurry obtained in step (2) is cooled to below 45℃, the amine chain extender and the liquid raw material of the intelligent protection system and the auxiliary agent are added in sequence, and then they are uniformly mixed by low-speed stirring under the condition that the rotation speed is 300-500 rpm; (4) Defoaming step: the final mixture obtained in step (3) is subjected to vacuum defoaming treatment under the condition that the vacuum degree is not less than -0.09MPa.

9. Use of the multiple synergistically reinforced polyurea elastomer material according to any one of claims 1 to 7, characterized in that The safety protection of the battery pack shell, chassis, or high-voltage components of new energy vehicles.

10. Use of a multiple synergistically reinforced polyurea elastomer material according to claim 9, characterized in that, The safety protection is a protective coating formed by the polyurea elastomer material on the surface of the battery pack shell, chassis, or high-voltage components, and the thickness of the protective coating is 2.0-3.0mm.

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