High-elasticity corrosion-resistant polyurea as well as preparation method and application thereof

Abstract

The invention relates to the technical field of polyurea production, in particular to high-elasticity corrosion-resistant polyurea as well as a preparation method and application thereof. Comprising the following raw materials in parts by weight: 50-70 parts of polyether amine D-2000; 15 to 25 parts of polyether amine D-400; 25 to 30 parts of PTMG-1000 (polytetramethylene terephthalate); 70 to 80 parts of H12MDI (diphenylmethane diisocyanate); 20 to 30 parts of IPDI (isophorone diisocyanate); 3 to 5 parts of an ethylenediamine-beta-cyclodextrin coating compound; 3 to 5 parts of 2-methyl piperazine; 0.5 to 1 part of a FeCoNiCrAlHEA nano cluster; 1 to 2 parts of graphene aerogel microspheres; 1 to 2 parts of an MXene coated SiO2 core-shell sheet; 0.5 to 1 part of fluorinated diamond; 0.5 to 1 part of cerium acetylacetonate; and 0.5 to 1 part of [EMIM] BF4 ionic liquid. According to the invention, through molecular design optimization and nano-filler synergistic enhancement, comprehensive improvement of performance is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of polyurea production, in particular to high-elasticity and corrosion-resistant polyurea and a preparation method and application thereof. Background Art

[0002] Polyurea, a polymer material formed by the reaction of isocyanates and amine compounds, is widely used in a variety of fields, including construction, transportation, and the chemical industry, thanks to its fast curing speed and excellent mechanical properties. In the field of plastic running tracks, polyurea is an ideal paving material due to its excellent wear resistance and elasticity.

[0003] However, traditional polyurea materials have numerous performance deficiencies in plastic track applications. In terms of elasticity and low-temperature tolerance, the traditional polyurea soft segment often utilizes a single polyetheramine, resulting in severe embrittlement at low temperatures, making it difficult to adapt to use scenarios with large temperature fluctuations. Elongation at break decreases significantly at low temperatures, impacting the track's elasticity and safety. Weather resistance and high-temperature stability are also poor. The MDI / TDI used in the hard segment is prone to yellowing under high temperatures and UV exposure, and strength retention is low at high temperatures. The appearance and performance of the track degrade significantly after long-term use. Wear and corrosion resistance are also insufficient. Conventional nanofillers suffer from weak interfacial bonding and agglomeration, leading to high material wear. Furthermore, the material is susceptible to flaking and pitting in corrosive environments such as acid rain, shortening the track's service life. Process bottlenecks also exist. Single-temperature curing results in inadequate microphase separation of the polyurea. Traditional spray coating processes have weak interfacial bonding and lack effective surface strengthening methods, resulting in a short fatigue life, making it difficult to meet the demands of long-term, high-frequency use of plastic tracks. Summary of the Invention

[0004] In view of the above deficiencies in the prior art, the purpose of the present invention is to provide a highly elastic and corrosion-resistant polyurea, which achieves comprehensive performance improvement through molecular design optimization and synergistic enhancement of nanofillers.

[0005] Another object of the present invention is to provide a method for preparing highly elastic and corrosion-resistant polyurea, which effectively improves the adhesion between the material and the substrate through laser pretreatment and shot peening technology, introduces compressive stress to improve fatigue life; gradient curing achieves precise control of phase domain size, ensuring a high retention rate of the material's elastic modulus.

[0006] The third object of the present invention is to provide an application of highly elastic and corrosion-resistant polyurea for use in plastic tracks with large temperature differences.

[0007] The present invention is achieved by adopting the following technical solutions: The highly elastic and corrosion-resistant polyurea comprises the following raw materials in parts by weight: 50-70 parts of polyetheramine D-2000; 15-25 parts of polyetheramine D-400; 25-30 parts of PTMG-1000; 70-80 parts of H12MDI; 20-30 parts of IPDI; 3-5 parts of ethylenediamine-β-cyclodextrin coating; 3-5 parts of 2-methylpiperazine; 0.5-1 part of FeCoNiCrAlHEA nanoclusters; 1-2 parts of graphene aerogel microspheres; 1-2 parts of MXene@SiO2 core-shell sheets; 0.5-1 part of fluorinated diamond; 0.5-1 part of cerium acetylacetonate; and 0.5-1 part of [EMIM]BF4 ionic liquid.

[0008] The preparation method of the ethylenediamine-β-cyclodextrin coating is as follows: dissolving β-cyclodextrin in a 55-58°C aqueous solution, adding ethylenediamine dropwise, standing at 3-4°C for 24-28 hours, filtering and drying to obtain the obtained product; the mass ratio of β-cyclodextrin to ethylenediamine is 10:(2-4).

[0009] The method for preparing the highly elastic and corrosion-resistant polyurea comprises the following steps: (1) Prepolymer synthesis: Mix the soft segment materials polyetheramine D-2000, polyetheramine D-400 and PTMG-1000, dehydrate under vacuum, cool, add the hard segment materials H12MDI and IPDI, and react for 3-3.5 hours to obtain material A; (2) Preparation of chain extension system: ethylenediamine-β-cyclodextrin coating and 2-methylpiperazine were mixed, and pre-assembled nanofillers: FeCoNiCrAlHEA nanoclusters, MXene@SiO2 core-shell sheets, and fluorinated diamond were added. The mixture was dispersed at 1800-2000 rpm for 30-40 min, and three-roll milling was performed to make the fineness ≤20 μm. Then, functionalized aerogel prepared by graphene aerogel microspheres, [EMIM]BF4 ionic liquid and cerium acetylacetonate was added, and the mixture was stirred at 200-220 rpm for 2-3 h to obtain material B. (3) Laser-assisted spraying: First, pre-treat the substrate; then, use the spraying equipment GusmerGX-9 to discharge material A and material B in a volume ratio of 1:1 and perform high-pressure atomization spraying; (4) Gradient curing: The product obtained in step (3) is kept at a constant temperature of 80-82°C for 1-1.5 hours, then at a constant temperature of 120°C for 1.5-1.8 hours, and then at a constant temperature of 120-125°C for 1-1.5 hours, UV curing (when the coating thickness is ≤1mm, the 365nm ultraviolet light transmittance is ≥15%) for 10-15 minutes, and then CO2 laser remelting and 355nm pulse laser shot peening are performed in sequence to obtain highly elastic and corrosion-resistant polyurea.

[0010] In the step (1), the vacuum dehydration conditions are as follows: vacuum dehydration at 110-115°C for 2-2.5h, cooling to 75-78°C, and the reaction conditions are as follows: under nitrogen protection, the reaction temperature is 82-85°C; the NCO% of material A is 10.2-16.8%.

[0011] The processing steps of the preassembled nanofiller are as follows: FeCoNiCrAlHEA nanoclusters and MXene@SiO2 core-shell sheets are added to a planetary mixer, 0.5% of the total weight of the preassembled nanofiller is added as a silane coupling agent KH-560, the temperature is raised to 110-112°C, the reaction is carried out for 2-3 hours, the temperature is then lowered to 80-85°C, fluorinated diamond is added, and the mixture is stirred at 2000 rpm for 1-1.5 hours to form a preassembled nanomaterial with a "core-shell-satellite" structure. During the above treatment process, 30 parts by weight of ethanol can be added when the silane coupling agent is added, and ultrasonic treatment is performed at 40kHz, 2 hours, and a power density of 300W / m 3 .

[0012] In step (2), the functionalized aerogel is prepared by vacuum impregnating the graphene aerogel with [EMIM]BF4 ionic liquid, adding cerium acetylacetonate, and stirring for 30-45 minutes. The impregnation temperature is 60°C, and the stirring temperature is 60°C.

[0013] In step (3), substrate pretreatment is achieved using an Nd:YAG laser with a wavelength of 1064 nm and an energy density of 20 J / cm². During high-pressure atomization spraying, the temperature of material A is 75°C, and the temperature of material B is 70°C, at 2500 psi. In step (4), the CO2 laser remelting conditions are a wavelength of 10.6 μm, a power of 500 W, and a scanning speed of 10 mm / s. The conditions for 355 nm pulsed laser shot peening are: an Nd:YAG pulsed laser with a pulse energy of 1 J. Laser shot peening is performed with air cooling, a wind speed of 5 m / s, and a room temperature of 25°C. The surface temperature of the laser shot peening area is ≤280°C.

[0014] In the step (4), the UV curing conditions are: 365nm; 40mW / cm².

[0015] The application of the highly elastic and corrosion-resistant polyurea is used for plastic tracks with large temperature differences.

[0016] The pretreatment method of MXene@SiO2 core-shell sheets is: plasma activation under vacuum degree 10Pa, interpole distance 50mm: Ar / O2=4:1 mixed gas, 300W / 5min.

[0017] In terms of molecular design, a soft segment ternary compound system is adopted. The ether bond flexibility of PTMG-1000 and the short-chain cross-linking of D-400 work synergistically to significantly reduce the glass transition temperature to -65°C, effectively improving low-temperature elasticity; the hard segment uses a combination of H12MDI alicyclic structure and IPDI rigid ring. H12MDI can inhibit ultraviolet degradation, and IPDI can resist thermal relaxation, significantly enhancing weather resistance and high-temperature stability.

[0018] Nanofillers form a multi-level reinforcement mechanism. FeCoNiCrAlHEA nanoclusters serve as hard and wear-resistant phases. Their Cr and Al elements migrate to the interface to form a nano-passivation film, blocking corrosion channels. MXene@SiO2 builds an efficient thermal conductive network. The SiO2 shell prevents MXene oxidation and reduces interfacial thermal stress through thermal conduction paths. Fluorinated diamond migrates to the surface with the help of ionic liquid released by the aerogel under pressure, forming a self-healing layer and reducing the friction coefficient. Graphene aerogel stores [EMIM]BF4 ionic liquid with a porosity of 95%, ensuring low-temperature fluidity for energy dissipation.

[0019] The chain extension reaction kinetics are precisely controlled. The β-cyclodextrin cavity wraps around ethylenediamine, which is gradually released after heating, reducing the reaction activation energy and avoiding sudden polymerization to produce micropores. 2-methylpiperazine locks the piperazine ring conformation, greatly improving the material's fatigue resistance.

[0020] Compared with the prior art, the present invention has the following beneficial effects: (1) The highly elastic and corrosion-resistant polyurea prepared by the present invention achieves comprehensive performance improvements through molecular design optimization and nanofiller synergistic enhancement. The material has excellent high and low temperature elasticity, solving the problems of low-temperature embrittlement and high-temperature performance degradation of traditional polyurea. The wear and corrosion resistance are greatly improved, extending the service life of the material. At the same time, the VOC emission is reduced, making it more environmentally friendly, meeting the dual requirements of high performance and environmental protection for plastic tracks.

[0021] (2) This invention effectively improves the adhesion between the material and the substrate through laser pretreatment and shot peening technology, and introduces compressive stress to improve fatigue life. Gradient curing achieves precise control of phase domain size, ensuring high retention of the material's elastic modulus. The entire preparation process is stable, and the pre-assembly and functionalization of nanofillers ensures uniform dispersion of the fillers in the matrix, further enhancing the material's performance.

[0022] (3) The polyurea obtained by this invention is particularly suitable for plastic tracks with large temperature differences. In practical applications, it can provide stable impact absorption performance and vertical deformation performance. After long-term temperature cycle testing, it has no cracks, solving the problem that traditional polyurea tracks are easily damaged in temperature-differential environments. The long service life and low overall cost make this solution have significant application value and economic advantages in the field of plastic tracks. DETAILED DESCRIPTION

[0023] In order to make the purpose and technical solution of the present invention more clear, the present invention is further described in detail below.

[0024] Polyetheramine D-2000: a commercial product of Huntsman Petrochemical Co., Ltd. Polyetheramine D-400: a commercial product of Huntsman Petrochemical Co., Ltd.; PTMG-1000: a commercial product of BASF SE; H12MDI: NCO content 23.5±0.3%, cyclohexane dimethylene diisocyanate, commercially available from Covestro AG; IPDI: content 37.5-38.5%, isophorone diisocyanate, a commercial product of Evonik Industries; β-Cyclodextrin: commercially available product from Sigma-Aldrich (Shanghai) Trading Co., Ltd. 2-Methylpiperazine: commercially available from Shanghai MacLean Biochemical Technology Co., Ltd. FeCoNiCrAlHEA nanoclusters (particle size 50±5 nm, FeCoNiCrAl atomic ratio of 1:1:1:1:1) were prepared by laser liquid-phase ablation. A metal target (Fe, Co, Ni, Cr, and Al, all 99.9% pure) was placed in an atomic ratio of 1:1:1:1:1 in a reaction vessel, and anhydrous ethanol was added until the target was submerged. A 1064 nm Nd:YAG pulsed laser (pulse energy 500 mJ, frequency 10 Hz, spot diameter 2 mm) was vertically irradiated onto the target surface and ablated under argon for 2 h. The resulting suspension was centrifuged at 12,000 rpm for 15 min, and the precipitate was collected, washed three times with anhydrous ethanol, and finally dried in a vacuum at 60°C to obtain FeCoNiCrAlHEA nanoclusters with a particle size of 50±5 nm.

[0025] MXene@SiO2 core-shell sheet: Ti3C2T x Core, SiO2 shell thickness 20±5nm; commercially available product from Beijing Graphene Research Institute; Fluorinated diamond: particle size 100 nm, fluorine content ≥ 5 at%, commercially available from Shanghai Aladdin Biochemical Technology Co., Ltd. Cerium acetylacetonate: Ce content ≥ 24%, commercially available from Sinopharm Chemical Reagent Co., Ltd. [EMIM][BF4]: Purity ≥ 99.5%, water content ≤ 50 ppm, commercially available from the Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences; Silane coupling agent KH-560: γ-glycidyloxypropyltrimethoxysilane, commercially available from Maitu Advanced Materials (Nantong) Co., Ltd. α-Al2O3 nanopowder: specific surface area 100±15m 2 / g, commercially available product of Evonik Industries AG.

[0026] Example 1 The highly elastic and corrosion-resistant polyurea comprises the following raw materials in parts by weight: 50 parts of polyetheramine D-2000; 15 parts of polyetheramine D-400; 25 parts of PTMG-1000; 70 parts of H12MDI; 20 parts of IPDI; 3 parts of ethylenediamine-β-cyclodextrin coating; 3 parts of 2-methylpiperazine; 0.5 parts of FeCoNiCrAlHEA nanoclusters; 1 part of graphene aerogel microspheres; 1 part of MXene@SiO2 core-shell sheets; 0.5 parts of fluorinated diamond; 0.5 parts of cerium acetylacetonate; and 0.5 parts of [EMIM]BF4 ionic liquid.

[0027] The preparation method of the ethylenediamine-β-cyclodextrin coating is as follows: dissolving β-cyclodextrin in a 55°C aqueous solution, adding ethylenediamine dropwise, standing at 3°C ​​for 24 hours, filtering and drying to obtain the obtained product; the mass ratio of β-cyclodextrin to ethylenediamine is 10:2.

[0028] The preparation method of highly elastic and corrosion-resistant polyurea comprises the following steps: (1) Prepolymer synthesis: Mix the soft segment materials polyetheramine D-2000, polyetheramine D-400 and PTMG-1000, dehydrate under vacuum, cool, add the hard segment materials H12MDI and IPDI, and react for 3 hours to obtain material A; (2) Preparation of chain extension system: Ethylenediamine-β-cyclodextrin coating and 2-methylpiperazine were mixed, and pre-assembled nanofillers: FeCoNiCrAlHEA nanoclusters, MXene@SiO2 core-shell sheets, and fluorinated diamond were added. The mixture was dispersed at 1800 rpm for 30 min and subjected to triple-roll grinding to a fineness of 20 μm. Then, functionalized aerogel prepared from graphene aerogel microspheres, [EMIM]BF4 ionic liquid, and cerium acetylacetonate was added. The mixture was stirred at 200 rpm for 3 h to obtain material B. (3) Laser-assisted spraying: First, pre-treat the substrate; then, use the Gusmer GX-9 equipment to discharge material A and material B in a volume ratio of 1:1 and perform high-pressure atomization spraying; (4) Gradient curing: The product obtained in step (3) was kept at a constant temperature of 80°C for 1 hour, then at a constant temperature of 120°C for 1.5 hours, and then at a constant temperature of 120°C for 1 hour, UV cured for 10 minutes, and then CO2 laser remelting and 355nm pulsed laser shot peening were performed in sequence to obtain highly elastic and corrosion-resistant polyurea.

[0029] In step (1), the vacuum dehydration conditions are vacuum dehydration at 110°C for 2h, cooling to 75°C, and the reaction conditions are carried out under nitrogen protection at a reaction temperature of 82°C; the NCO% of material A is 13.3%.

[0030] The preassembled nanofillers were processed as follows: FeCoNiCrAlHEA nanoclusters and MXene@SiO2 core-shell sheets were added to a planetary mixer, followed by the addition of silane coupling agent KH-560 (0.5% by weight of the total preassembled nanofiller mass). The mixture was heated to 110°C and allowed to react for 2 hours. The mixture was then cooled to 80°C, fluorinated diamond was added, and stirred at 2000 rpm for 1 hour. The functionalized aerogel was prepared by vacuum impregnating the graphene aerogel with [EMIM]BF4 ionic liquid, adding cerium acetylacetonate, and stirring for 30 minutes. The impregnation and stirring temperatures were 60°C.

[0031] In step (3), substrate pretreatment was achieved using an Nd:YAG laser with a wavelength of 1064 nm and an energy density of 20 J / cm². During high-pressure atomization spraying, the temperature of material A was 75°C, and the temperature of material B was 70°C, at 2500 psi. In step (4), the CO2 laser remelting conditions were a wavelength of 10.6 μm, a power of 500 W, and a scanning speed of 10 mm / s. The conditions for 355 nm pulsed laser shot peening were: an Nd:YAG pulsed laser with a pulse energy of 1 J. UV curing conditions were: 365 nm UV at 40 mW / cm².

[0032] Example 2 The highly elastic and corrosion-resistant polyurea comprises the following raw materials in parts by weight: 60 parts of polyetheramine D-2000; 20 parts of polyetheramine D-400; 28 parts of PTMG-1000; 75 parts of H12MDI; 25 parts of IPDI; 4 parts of ethylenediamine-β-cyclodextrin coating; 4 parts of 2-methylpiperazine; 0.75 parts of FeCoNiCrAlHEA nanoclusters; 2 parts of graphene aerogel microspheres; 2 parts of MXene@SiO2 core-shell sheets; 1 part of fluorinated diamond; 1 part of cerium acetylacetonate; and 1 part of [EMIM]BF4 ionic liquid.

[0033] The preparation method of the ethylenediamine-β-cyclodextrin coating is as follows: dissolving β-cyclodextrin in a 56°C aqueous solution, adding ethylenediamine dropwise, standing at 4°C for 28 hours, filtering and drying to obtain the obtained product; the mass ratio of β-cyclodextrin to ethylenediamine is 10:3.

[0034] The preparation method of highly elastic and corrosion-resistant polyurea comprises the following steps: (1) Prepolymer synthesis: After mixing the soft segment materials polyetheramine D-2000, polyetheramine D-400 and PTMG-1000, vacuum dehydration, cooling, adding hard segment materials H12MDI and IPDI, and reacting for 3.5 hours to obtain material A; (2) Preparation of chain extension system: Ethylenediamine-β-cyclodextrin coating and 2-methylpiperazine were mixed, and pre-assembled nanofillers: FeCoNiCrAlHEA nanoclusters, MXene@SiO2 core-shell sheets, and fluorinated diamond were added. The mixture was dispersed at 2000 rpm for 40 min and subjected to triple-roll grinding to a fineness of 20 μm. Then, functionalized aerogel prepared from graphene aerogel microspheres, [EMIM]BF4 ionic liquid, and cerium acetylacetonate was added. The mixture was stirred at 210 rpm for 3 h to obtain material B. (3) Laser-assisted spraying: First, pre-treat the substrate; then, use the Gusmer GX-9 equipment to discharge material A and material B in a volume ratio of 1:1 and perform high-pressure atomization spraying; (4) Gradient curing: The product obtained in step (3) was kept at a constant temperature of 81°C for 1.5 hours, then at a constant temperature of 120°C for 1.8 hours, and then at a constant temperature of 125°C for 1.5 hours, UV cured for 15 minutes, and then CO2 laser remelting and 355nm pulsed laser shot peening were performed to obtain highly elastic and corrosion-resistant polyurea.

[0035] In step (1), the vacuum dehydration conditions are as follows: vacuum dehydration at 115°C for 2.5 hours, cooling to 78°C, and the reaction conditions are as follows: reaction under nitrogen protection at a temperature of 85°C; the NCO% of material A is 11.7%.

[0036] The preassembled nanofillers were processed as follows: FeCoNiCrAlHEA nanoclusters and MXene@SiO2 core-shell sheets were placed in a planetary mixer, followed by the addition of silane coupling agent KH-560 (0.5% by weight of the total preassembled nanofiller mass). The mixture was heated to 112°C and allowed to react for 3 hours. The mixture was then cooled to 85°C, fluorinated diamond was added, and stirred at 2000 rpm for 1.5 hours. The functionalized aerogel was prepared by vacuum impregnating the graphene aerogel with [EMIM]BF4 ionic liquid, adding cerium acetylacetonate, and stirring for 40 minutes. The impregnation and stirring temperatures were 60°C.

[0037] In step (3), substrate pretreatment was achieved using an Nd:YAG laser with a wavelength of 1064 nm and an energy density of 20 J / cm². During high-pressure atomization spraying, the temperature of material A was 75°C, and the temperature of material B was 70°C, at 2500 psi. In step (4), the CO2 laser remelting conditions were a wavelength of 10.6 μm, a power of 500 W, and a scanning speed of 10 mm / s. The conditions for 355 nm pulsed laser shot peening were: an Nd:YAG pulsed laser with a pulse energy of 1 J. UV curing conditions were: 365 nm UV at 40 mW / cm².

[0038] Example 3 The highly elastic and corrosion-resistant polyurea comprises the following raw materials in parts by weight: polyetheramine D-2000: 70 parts; polyetheramine D-400: 25 parts; PTMG-1000: 30 parts; H12MDI: 80 parts; IPDI: 30 parts; ethylenediamine-β-cyclodextrin coating: 5 parts; 2-methylpiperazine: 5 parts; FeCoNiCrAlHEA nanoclusters: 1 part; graphene aerogel microspheres: 2 parts; MXene@SiO2 core-shell sheets: 2 parts; fluorinated diamond: 1 part; cerium acetylacetonate: 1 part; and [EMIM]BF4 ionic liquid: 1 part.

[0039] The preparation method of the ethylenediamine-β-cyclodextrin coating is as follows: dissolving β-cyclodextrin in a 58°C aqueous solution, adding ethylenediamine dropwise, standing at 4°C for 28 hours, filtering and drying, and obtaining the obtained product; the mass ratio of β-cyclodextrin to ethylenediamine is 10:4.

[0040] The preparation method of highly elastic and corrosion-resistant polyurea comprises the following steps: (1) Prepolymer synthesis: After mixing the soft segment materials polyetheramine D-2000, polyetheramine D-400 and PTMG-1000, vacuum dehydration, cooling, adding hard segment materials H12MDI and IPDI, and reacting for 3.5 hours to obtain material A; (2) Preparation of chain extension system: Ethylenediamine-β-cyclodextrin coating and 2-methylpiperazine were mixed, and pre-assembled nanofillers: FeCoNiCrAlHEA nanoclusters, MXene@SiO2 core-shell sheets, and fluorinated diamond were added. The mixture was dispersed at 2000 rpm for 40 min and subjected to triple-roll grinding to a fineness of 20 μm. Then, functionalized aerogel prepared from graphene aerogel microspheres, [EMIM]BF4 ionic liquid, and cerium acetylacetonate was added. The mixture was stirred at 220 rpm for 3 h to obtain material B. (3) Laser-assisted spraying: First, pre-treat the substrate; then, use the Gusmer GX-9 equipment to discharge material A and material B in a volume ratio of 1:1 and perform high-pressure atomization spraying; (4) Gradient curing: The product obtained in step (3) was kept at a constant temperature of 82°C for 1.5 hours, then at a constant temperature of 120°C for 1.8 hours, and then at a constant temperature of 125°C for 1.5 hours, UV cured for 15 minutes, and then CO2 laser remelting and 355nm pulsed laser shot peening were performed to obtain highly elastic and corrosion-resistant polyurea.

[0041] In step (1), the vacuum dehydration conditions are as follows: vacuum dehydration at 115°C for 2.5 hours, cooling to 78°C, and the reaction conditions are as follows: the reaction is carried out under nitrogen protection at a reaction temperature of 85°C; the NCO% of material A is 12.8%.

[0042] The preassembled nanofiller was processed as follows: FeCoNiCrAlHEA nanoclusters and MXene@SiO2 core-shell sheets were placed in a planetary mixer, followed by the addition of silane coupling agent KH-560 (0.5% by weight of the total preassembled nanofiller mass). The mixture was heated to 112°C and allowed to react for 3 hours. The temperature was then lowered to 85°C, and fluorinated diamond was added. The mixture was stirred at 2000 rpm for 1.5 hours. This resulted in a preassembled nanofiller with a "core-shell-satellite" structure. The functionalized aerogel was prepared by vacuum impregnating the graphene aerogel with [EMIM]BF4 ionic liquid, adding cerium acetylacetonate, and stirring for 45 minutes. The impregnation and stirring temperatures were 60°C.

[0043] In step (3), substrate pretreatment was achieved using an Nd:YAG laser with a wavelength of 1064 nm and an energy density of 20 J / cm². During high-pressure atomization spraying, the temperature of material A was 75°C, and the temperature of material B was 70°C, at 2500 psi. In step (4), the CO2 laser remelting conditions were a wavelength of 10.6 μm, a power of 500 W, and a scanning speed of 10 mm / s. The conditions for 355 nm pulsed laser shot peening were: an Nd:YAG pulsed laser with a pulse energy of 1 J. UV curing conditions were: 365 nm UV at 40 mW / cm².

[0044] Comparative Example 1 The difference from Example 2 is that the filler pre-assembly is cancelled and the untreated filler is directly added.

[0045] Comparative Example 2 The difference from Example 1 is that the cyclodextrin coating is replaced by DETDA in an equimolar ratio.

[0046] Comparative Example 3 The difference from Example 2 is that the gradient curing is changed to constant temperature curing at 120° C. for 4 hours.

[0047] Comparative Example 4 The difference from Example 2 is that the laser shot peening process is removed.

[0048] Comparative Example 5 The difference from Example 2 is that HEA is replaced by α-Al2O3 nanopowder, and 0.75 parts are added in an equal amount.

[0049] The test data of Examples 1-3 are shown in Table 1.

[0050] The test data of Comparative Examples 1-5 are shown in Table 2.

[0051] Table 1: Test data of Examples 1-3

[0052] VOC emission test conditions: 23°C, 50±5% RH, sampling time 24 hours. The substrate was laser-textured (Sa = 5μm). Cohesive failure occurred during the adhesion test.

[0053] Table 2: Test data of comparative examples 1-5

[0054] VOC emission test conditions: 23°C, 50±5%RH, sampling time 24h.

[0055] As can be seen from Tables 1 and 2, the product performance advantages of this solution are significant. In terms of mechanical properties, Example 2 achieved a tensile strength of 28 MPa, an elongation at break of 480%, and a tear strength of 38 kN / m, all significantly higher than the comparative examples. In particular, in terms of low-temperature performance, the elongation at break at -20°C was 250%, and the -30°C impact test showed no cracks, resolving the low-temperature embrittlement problem of traditional materials. Wear and corrosion resistance were outstanding, with Example 2 showing a Taber abrasion loss of only 38 mg / 100 revolutions, far lower than the 62 mg / 100 revolutions of Comparative Example 1 and the 68 mg / 100 revolutions of Comparative Example 5. The acid rain resistance test showed no change, while Comparative Example 1 exhibited flaking and Comparative Example 5 exhibited pitting corrosion, demonstrating that the synergistic effect of the nanofillers effectively improved wear and corrosion resistance. In terms of adhesion and environmental friendliness, Example 2 achieved substrate adhesion of 15.6 MPa, far exceeding the 6.3 MPa of Comparative Example 1. The VOC emission was 26 mg / m³, meeting environmental standards and lower than most comparative examples.

[0056] Application Example 1 The highly elastic, corrosion-resistant polyurea obtained in Example 2 was applied to a plastic track. The concrete base was first treated to a moisture content of 5% and a flatness of 3mm / 2m. The coating thickness was 8mm (applied in two stages). Laser texturing was performed using Nd:YAG at 20J / cm². The ambient temperature was controlled at 25°C and the humidity was 40%. The concrete substrate had a tensile strength of ≥3.5MPa (GB / T50081) and was laser texturing treated before spraying, with a Sa of 5μm.

[0057] Comparative Application Example 1 The polyurea obtained in Comparative Example 3 was used for the plastic track, and the treatment method was the same as that in Application Example 1.

[0058] The test data of Application Example 1 and Application Comparative Example 1 are shown in Table 3.

[0059] Table 3: Test data of Application Example 1 and Application Comparative Example 1

[0060] As shown in Table 3, in the application test, the impact absorption rate of Application Example 1 is 38.2%, the elasticity retention rate at -20°C is 92%, and there is no crack after 100 temperature difference cycles, which is significantly better than Application Comparative Example 1, fully verifying the advantages of this solution in the application of plastic tracks.

Claims

1. A highly elastic and corrosion-resistant polyurea, characterized in that: The invention comprises the following raw materials in parts by weight: polyetheramine D-2000: 50-70 parts; polyetheramine D-400: 15-25 parts; PTMG-1000: 25-30 parts; H12MDI: 70-80 parts; IPDI: 20-30 parts; ethylenediamine-β-cyclodextrin coating: 3-5 parts; 2-methylpiperazine: 3-5 parts; FeCoNiCrAlHEA nanoclusters: 0.5-1 parts; graphene aerogel microspheres: 1-2 parts; MXene@SiO2 core-shell sheets: 1-2 parts; fluorinated diamond: 0.5-1 parts; cerium acetylacetonate: 0.5-1 parts; and [EMIM]BF4 ionic liquid: 0.5-1 parts.

2. The highly elastic and corrosion-resistant polyurea according to claim 1, characterized in that: The preparation method of the ethylenediamine-β-cyclodextrin coating is as follows: dissolving β-cyclodextrin in a 55-58°C aqueous solution, adding ethylenediamine dropwise, standing at 3-4°C for 24-28 hours, filtering and drying to obtain the obtained product; the mass ratio of β-cyclodextrin to ethylenediamine is 10:(2-4).

3. A method for preparing the highly elastic and corrosion-resistant polyurea according to claim 1 or 2, characterized in that: The following steps are involved: (1) Prepolymer synthesis: Mix the soft segment materials polyetheramine D-2000, polyetheramine D-400 and PTMG-1000, dehydrate under vacuum, cool, add the hard segment materials H12MDI and IPDI, and react for 3-3.5 hours to obtain material A; (2) Preparation of chain extension system: ethylenediamine-β-cyclodextrin coating and 2-methylpiperazine were mixed, and pre-assembled nanofillers: FeCoNiCrAlHEA nanoclusters, MXene@SiO2 core-shell sheets, and fluorinated diamond were added. The mixture was dispersed at 1800-2000 rpm for 30-40 min, and three-roll milling was performed to make the fineness ≤20 μm. Then, functionalized aerogel prepared by graphene aerogel microspheres, [EMIM]BF4 ionic liquid and cerium acetylacetonate was added, and the mixture was stirred at 200-220 rpm for 2-3 h to obtain material B. (3) Laser-assisted spraying: First, pre-treat the substrate; then, use the spraying equipment to discharge material A and material B in a volume ratio of 1:1 and perform high-pressure atomization spraying; (4) Gradient curing: The product obtained in step (3) is kept at a constant temperature of 80-82°C for 1-1.5 hours, then at a constant temperature of 120°C for 1.5-1.8 hours, and then at a constant temperature of 120-125°C for 1-1.5 hours, UV cured for 10-15 minutes, and then CO2 laser remelting and 355nm pulsed laser shot peening are performed on it in sequence; high elasticity and corrosion-resistant polyurea is obtained.

4. The method for preparing highly elastic and corrosion-resistant polyurea according to claim 3, characterized in that: In the step (1), the vacuum dehydration conditions are as follows: vacuum dehydration at 110-115°C for 2-2.5h, cooling to 75-78°C, and the reaction conditions are as follows: under nitrogen protection, the reaction temperature is 82-85°C; the NCO% of material A is 10.2-16.8%.

5. The method for preparing highly elastic and corrosion-resistant polyurea according to claim 3, characterized in that: In the step (2), the processing steps of the preassembled nanofiller are as follows: FeCoNiCrAlHEA nanoclusters and MXene@SiO2 core-shell sheets are added to a planetary mixer, 0.5% of the total mass of the preassembled nanofiller and silane coupling agent KH-560 are added, the temperature is raised to 110-112°C, the reaction is carried out for 2-3 hours, the temperature is then lowered to 80-85°C, fluorinated diamond is added, and the mixture is stirred at 2000 rpm for 1-1.5 hours.

6. The method for preparing highly elastic and corrosion-resistant polyurea according to claim 3, characterized in that: In the step (2), the preparation method of the functionalized aerogel is as follows: vacuum impregnating the graphene aerogel with [EMIM]BF4 ionic liquid, adding cerium acetylacetonate and stirring for 30-45 minutes to obtain the functionalized aerogel.

7. The method for preparing highly elastic and corrosion-resistant polyurea according to claim 3, characterized in that: In the step (3), the substrate pretreatment is achieved by a Nd:YAG laser with a wavelength of 1064nm and an energy density of 20J / cm²; in the high-pressure atomization spraying, the temperature of material A is 75°C, and the temperature of material B is 70°C, 2500psi; in the step (4), the conditions for CO2 laser remelting are a wavelength of 10.6μm, a power of 500W, and a scanning speed of 10mm / s; the conditions for 355nm pulsed laser shot peening are: using an Nd:YAG pulsed laser with a pulse energy of 1J.

8. The method for preparing highly elastic and corrosion-resistant polyurea according to claim 3, characterized in that: In the step (4), the UV curing conditions are: 365nm; 40mW / cm².

9. Use of the highly elastic and corrosion-resistant polyurea according to claim 1 or 2, characterized in that: Used for plastic tracks with large temperature differences.

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