Environment-friendly railway turnout coating and preparation method thereof

Abstract

This invention discloses a method for preparing an environmentally friendly railway turnout coating, relating to the field of railway turnout coating technology. The method involves forming a modified graphene oxide suspension grafted with polydopamine; generating a polyurea resin shell in situ on the surface of lubricating oil droplets via interfacial polymerization to obtain a surface-armored self-lubricating microcapsule dispersion; obtaining an aqueous polyurethane prepolymer emulsion containing side-group double bonds; constructing molecular-level interfacial crosslinking to obtain an organic-inorganic hybrid coating crosslinking slurry; and obtaining an environmentally friendly railway turnout coating with a micro-nano multi-level anti-slip and self-healing lubrication network. This invention ensures that the microcapsules do not collapse prematurely under extremely high wheel-rail contact stress, significantly improving the microcapsules' critical fracture threshold and environmental performance.

Description

Technical Field

[0001] This invention relates to the field of railway turnout coating technology, and in particular to an environmentally friendly railway turnout coating and its preparation method. Background Technology

[0002] With the rapid expansion of high-speed railways and heavy-haul freight networks, railway turnouts, as key hubs for track switching, are highly susceptible to severe wear due to the high-frequency impact and extremely high mechanical loads of the core moving components of the slide plates under train wheelsets. To ensure smooth and reliable turnout switching, continuous lubrication intervention at the turnout friction interface is essential. However, current railway maintenance operations face numerous insurmountable challenges in turnout lubrication and surface protective coating technologies.

[0003] Traditional turnout lubrication methods typically rely on manual brushing or mechanical spraying of liquid lubricating oil and heavy-duty grease. Mineral oil-based lubricants are highly susceptible to runoff under complex outdoor climates, leading to extremely short lubrication cycles, significantly increased maintenance costs, and the lost greases containing heavy metals, polycyclic aromatic hydrocarbons, and volatile organic compounds, causing serious secondary pollution to the soil ecology and groundwater environment along the railway line.

[0004] To overcome the problem of easy grease loss, existing technologies have gradually introduced solid resin coatings containing friction-reducing fillers or self-lubricating microcapsules. The preparation process of traditional lubricating microcapsules usually relies on highly toxic formaldehyde crosslinking agents and small molecule chemical surfactants, which violates the requirements of green environmental protection from the source; moreover, the mechanical strength and surface activity of conventional capsule walls are extremely poor, causing the microcapsules to easily rupture prematurely over a large area under the extremely high shear load of the turnout, making it impossible to achieve a truly stress-responsive long-term sustained release.

[0005] As the complexity of coating systems increases, ensuring the uniform distribution and interfacial compatibility of functional fillers in the matrix becomes increasingly difficult. Traditional self-lubricating coatings typically involve only simple mechanical blending, lacking molecular-level chemical bonding between microcapsules and the matrix resin. During the lengthy film-forming process of traditional pure thermosetting or solvent evaporation drying, driven by thermodynamics and density differences, microcapsules are prone to disordered aggregation, sedimentation, or floating migration within the wet film. This results in an extremely uneven distribution of the lubrication network within the coating after film formation and also leads to the accumulation of significant shrinkage stress within the coating, triggering microcracks.

[0006] Traditional coating adhesion strengthening mechanisms typically rely on extensive substrate pretreatment methods such as pickling or sandblasting, which generate high pollution and dust. These methods fail to create multi-level micro-anchoring points with high surface energy on the high-manganese steel surface of turnouts, resulting in extremely limited interfacial bonding strength between the organic coating and the inorganic metal substrate. Under the alternating shear stress caused by high-frequency heavy-load train rolling, existing coatings are prone to interfacial debonding, brittle fracture, and even large-area peeling failure, failing to meet the stringent requirements of modern railways for maintenance-free turnout cycles. Summary of the Invention

[0007] One objective of this invention is to provide a method for preparing an environmentally friendly railway turnout coating. This invention ensures that the microcapsules do not collapse prematurely under extremely high wheel-rail contact stress, significantly improving the critical threshold for fracture resistance and environmental performance of the microcapsules.

[0008] According to an embodiment of the present invention, a method for preparing an environmentally friendly railway turnout coating includes: Graphene oxide was ultrasonically dispersed in a weakly alkaline buffer solution, and dopamine hydrochloride was added to carry out an in-situ self-polymerization reaction in the dark to grow a polydopamine active adhesion layer on the surface of the graphene oxide sheets, forming a modified graphene oxide suspension with surface-grafted polydopamine. Using a graphene oxide suspension with surface-grafted polydopamine as a solid particle emulsifier, environmentally friendly plant-based lubricating oil was subjected to high-speed shear dispersion, and a polyurea resin shell was generated in situ on the surface of the lubricating oil droplets through interfacial polymerization to obtain a surface-armored self-lubricating microcapsule dispersion. Aliphatic diisocyanate and bio-based polycarbonate diol were grafted and polymerized under the action of a catalyst, and a hydrophilic chain extender containing carbon-carbon double bonds was introduced for the reaction. After high-speed phase configuration conversion with deionized water, an aqueous polyurethane prepolymer emulsion containing side group double bonds was prepared. The surface-armored self-lubricating microcapsule dispersion was added dropwise to the aqueous polyurethane prepolymer emulsion containing side group double bonds for mechanical mixing. The end groups of the aqueous polyurethane prepolymer and the polydopamine layer on the surface of the microcapsules were dehydrated and condensed by adding a silane coupling agent to construct molecular-level interfacial crosslinking and obtain an organic-inorganic hybrid coating crosslinking slurry. Organic-inorganic hybrid coating crosslinking slurry was applied to the surface of the pretreated railway turnout substrate and subjected to UV-thermal dual-stage curing treatment. The side double bonds were induced to undergo free radical polymerization by UV light to instantly lock the spatial distribution of microcapsules. The deep condensation reaction of the prepolymer network was completed under the excitation of the heat source, resulting in an environmentally friendly railway turnout coating with a micro-nano multi-level anti-slip and self-healing lubrication network.

[0009] Optionally, the step of ultrasonically dispersing graphene oxide in a weakly alkaline buffer solution, adding dopamine hydrochloride to carry out a light-protected in-situ self-polymerization reaction to grow a polydopamine active adhesion layer on the surface of the graphene oxide sheets, forming a polydopamine-grafted modified graphene oxide suspension, includes: Graphene oxide powder was added to a composite buffer system and dispersed by multi-frequency cascade ultrasonication under strict low-temperature conditions. The active groups were finely exfoliated and retained to obtain a highly active precursor dispersion. In a light-proof and oxygen-free inert environment, dopamine monomer solution was targeted and added dropwise to the highly active precursor dispersion using microfluidic technology to obtain a mixed predispersant containing dopamine monomer. Sodium periodate oxidant was introduced into a mixed pre-dispersion containing dopamine monomers, and programmed temperature rise was performed to drive in-situ self-assembly crosslinking of dopamine to form a modified graphene oxide suspension with surface-grafted polydopamine.

[0010] Optionally, the modified graphene oxide suspension grafted with polydopamine is used as a solid particle emulsifier to perform high-speed shear dispersion of environmentally friendly plant-based lubricating oil, and a polyurea resin shell is generated in situ on the surface of the lubricating oil droplets through interfacial polymerization to obtain a surface-armored self-lubricating microcapsule dispersion, comprising: Plant-based lubricating oil and epoxidized soybean oil were physically blended and then subjected to micro-oxidation activation treatment with ozone to obtain a modified environmentally friendly plant-based lubricating oil core material with spontaneous interface enrichment tendency. A modified environmentally friendly plant-based lubricating oil core material was mixed with isocyanate to form an oil phase, and a high-shear dispersion was performed using a suspension of modified graphene oxide grafted with polydopamine as the sole emulsifier to construct a Pickering primary oil-in-water emulsion. A mixed amine chain extender was added dropwise to the aqueous phase of a primary oil-in-water emulsion in Pickering to drive asymmetric addition polymerization at the oil-water interface, generating a polyurea inner shell in situ and covalently anchoring it to the outer graphene oxide layer, resulting in a surface-armored self-lubricating microcapsule dispersion with a double-core-shell structure.

[0011] Optionally, the graft polymerization of aliphatic diisocyanate and bio-based polycarbonate diol under the action of a catalyst, and the introduction of a hydrophilic chain extender containing carbon-carbon double bonds for reaction, followed by high-speed phase configuration conversion with deionized water, yields an aqueous polyurethane prepolymer emulsion containing side group double bonds, comprising: Deep dehydration treatment of bio-based polycarbonate diols is performed using extreme negative pressure coupled with high temperature to remove trace amounts of moisture and impurities, resulting in high-purity dehydrated and activated diols. Under the action of a non-toxic composite catalyst, high-purity dehydrated and activated diols and aliphatic diisocyanates are bulk block copolymerized to synthesize the main chain backbone of polyurethane prepolymers. A hydrophilic chain extender containing carbon-carbon double bonds is inserted into the main chain backbone of a polyurethane prepolymer at specific points, and a neutralizing agent is added to perform incomplete neutralization treatment to obtain a functionalized prepolymer with a coiled main chain. Functionalized prepolymers were injected at high speed into deionized water using fluid rheological shear stress to induce phase inversion and complete secondary chain extension in the aqueous phase, thus preparing an aqueous polyurethane prepolymer emulsion containing side group double bonds.

[0012] Optionally, the process involves adding the surface-armored self-lubricating microcapsule dispersion dropwise to the aqueous polyurethane prepolymer emulsion containing side-group double bonds for mechanical mixing, and then adding a silane coupling agent to induce a dehydration condensation reaction between the end groups of the aqueous polyurethane prepolymer and the polydopamine layer on the microcapsule surface, thereby constructing a molecular-level interfacial crosslinking to obtain an organic-inorganic hybrid coating crosslinking slurry, comprising: Under a planetary biaxial shear force field, a surface-armored self-lubricating microcapsule dispersion is slowly injected into an aqueous polyurethane prepolymer emulsion containing side group double bonds in a fluid pulse manner to obtain a biphase physical premixed suspension in which the microcapsules are uniformly suspended. The silane coupling agent containing epoxy groups is placed in a weakly acidic mixed solvent and pre-hydrolyzed at controlled room temperature to convert it into a pre-hydrolyzed coupling agent containing active silanol groups. The pre-hydrolyzed coupling agent is atomized and added to the biphase physical premixed suspension, and the mixture is heated and stirred at a constant temperature. This drives the two ends of the silane coupling agent to undergo bidirectional topological chemical bonding with the surface of the microcapsule and the end of the prepolymer molecular chain, respectively, thus completely eliminating macroscopic phase separation and obtaining an organic-inorganic hybrid coating crosslinking slurry.

[0013] Optionally, the organic-inorganic hybrid coating crosslinking slurry is coated onto the pretreated railway turnout substrate surface, and a UV-thermal dual-stage curing treatment is performed to finally form an environmentally friendly railway turnout coating with a micro-nano multi-level anti-slip and self-healing lubrication network, comprising: Nanosecond pulsed fiber lasers were used to perform vaporization stripping and local melting etching on railway turnout metal substrates to obtain multi-level microtextured high-energy metal substrates with significantly enhanced surface energy. Organic-inorganic hybrid coating crosslinking slurry is sprayed under high pressure without air onto the surface of a multi-level microtextured high-energy metal substrate. After capillary wetting and mechanical anchoring, an uncured wet film coating that fills the micro-pits is obtained. Applying dual-frequency synergistic ultraviolet radiation to an uncured wet film coating instantaneously triggers the free radical polymerization of side-chain double bonds, locking the three-dimensional network and microcapsule distribution of the coating, resulting in a photo-induced phase-locked semi-cured coating; A step-by-step heat treatment from low temperature to high temperature is performed on the photo-induced phase-locked semi-cured coating to drive the deep polycondensation of the polyurethane skeleton and silane network and release the internal stress accumulated by photocuring, and finally form a film to obtain an environmentally friendly railway turnout coating.

[0014] An environmentally friendly railway turnout coating, characterized in that the coating is prepared by any one of claims 1 to 6.

[0015] The beneficial effects of this invention are: This invention introduces modified graphene oxide grafted with polydopamine as the sole solid particulate emulsifier, enabling spontaneous assembly and in-situ generation of a polyurea resin inner shell on the surface of plant-based lubricating oil droplets. This constructs a bilayer armored self-lubricating microcapsule composed of high-toughness polyurea and high-modulus graphene oxide, achieving precise stress-responsive, long-lasting lubricant release under the conditions of high-frequency heavy-load shearing and extreme friction in railway turnouts. Through a bilayer rigid-flexible microstructure design and a green polymerization process using a pure aqueous phase interface, this invention ensures that the microcapsules do not collapse prematurely under extremely high wheel-rail contact stress, significantly improving the microcapsules' critical fracture threshold and environmental performance.

[0016] This invention employs a strictly controlled room-temperature pre-hydrolysis process on a silane coupling agent containing epoxy groups. This allows the two ends of the molecule to undergo dehydration condensation and ring-opening grafting with the polydopamine layer on the microcapsule surface and the aqueous polyurethane prepolymer containing side-group double bonds, respectively. This enables the model to focus more intently on the molecular-level bonding between the organic matrix and the inorganic filler interface. By introducing a bidirectional chemical bridging mechanism, the originally isolated self-lubricating microcapsules can be strongly anchored to a three-dimensional interpenetrating polyurethane network through covalent bonds. This dynamically eliminates the macroscopic phase separation interface, allowing the network to uniformly transfer loads under alternating shear stress, thereby more precisely locking the lubrication core.

[0017] This invention combines nanosecond pulsed laser microtexturing pretreatment with a dual-stage UV-thermal curing process. It utilizes dual-frequency synergistic UV light to instantaneously trigger the free radical polymerization of polyurethane side-chain double bonds, photo-locking the three-dimensional spatial network of the wet film coating. Leveraging the extremely rapid response of UV light, it instantly freezes and captures the perfectly uniform distribution of microcapsules in the slurry. Combined with step-by-step heat treatment to drive deep polycondensation and internal stress release of the prepolymer network, it completely eliminates the thermodynamic migration, agglomeration, and floating defects of microcapsules during the lengthy baking process. This invention not only constructs high-surface-energy biomimetic micron-level anchoring points on the metal substrate surface but also, through a disruptive kinetic path of "first photo-curing and then thermal curing," precisely predicts and controls the spatial position and stress evolution direction of each phase during the coating film formation process. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart of a method for preparing an environmentally friendly railway turnout coating proposed in this invention. Detailed Implementation

[0019] Example 1: Reference Figure 1 A method for preparing an environmentally friendly railway turnout coating, the method comprising: Graphene oxide was ultrasonically dispersed in a weakly alkaline buffer solution, and dopamine hydrochloride was added to carry out an in-situ self-polymerization reaction in the dark to grow a polydopamine active adhesion layer on the surface of the graphene oxide sheets, forming a modified graphene oxide suspension with surface-grafted polydopamine. In this embodiment, graphene oxide is ultrasonically dispersed in a weakly alkaline buffer solution, and dopamine hydrochloride is added to perform a light-protected in-situ self-polymerization reaction to grow a polydopamine active adhesion layer on the surface of the graphene oxide sheets, forming a polydopamine-grafted modified graphene oxide suspension, comprising: Customized pre-activation and multi-frequency cascade cavitation dispersion of graphene oxide: High-purity monolayer graphene oxide powder with a carbon-to-oxygen atomic ratio strictly controlled between 2.5:1 and 2.8:1, an average monolayer thickness of 0.8-1.2 nm, and a lateral size distribution in the range of 0.5-2.0 μm was selected as the core building block. The graphene oxide powder was added to a pre-prepared biomimetic weakly alkaline composite buffer system. The composite buffer system abandoned the conventional single inorganic salt system and instead consisted of a mixture of 0.05-0.15 mol / L tris(hydroxymethyl)aminomethane-hydrochloric acid solution and 0.01-0.03 mol / L bio-based L-histidine aqueous solution at a volume ratio of 3:1 to 5:1. The imidazole ring structure of L-histidine not only provides a strong secondary buffering capacity and maintains the high stability of the pH value of the system's microenvironment, but also generates strong intermolecular π-π electron conjugation stacking with the subsequently added dopamine molecules. The dispersion was achieved using a multi-frequency cascaded ultrasonic device. The first band of low-frequency ultrasonic treatment was activated for 15-20 minutes to break up macroscopic van der Waals aggregates without damage. The system then seamlessly switched to the second band of high-frequency ultrasonic treatment for 30-45 minutes to achieve fine exfoliation and solvation of the sheets. Throughout the multi-frequency cascaded cavitation dispersion process, a closed-loop temperature control network was formed by an external liquid nitrogen-ethylene glycol refrigerant jacket circulation system and an internal array of temperature sensors to strictly lock the core temperature of the dispersion system to no more than 4.5℃. The extremely low temperature ultrasonic environment completely broke the technical bias and thermodynamic trap of conventional room temperature ultrasonic dispersion, which easily leads to disordered shedding of oxygen-containing functional groups at the edge of graphene oxide due to local hot spot effects. This maximized the preservation of activated carboxyl groups at the edge of the sheets and epoxy groups in the plane, resulting in an extremely stable precursor dispersion with a concentration of 1.5-2.5 mg / mL and rich in high-energy reactive sites. Microfluidic targeted dropping and biomimetic catalytic graft polymerization of dopamine monomers: In a specially designed titanium alloy light-proof reactor completely shielded from 200-800nm ​​full-band ultraviolet and visible light sources, ultrapure argon gas with a purity of up to 99.999% was continuously introduced into the prepared precursor dispersion to completely replace dissolved oxygen and maintain an absolutely anaerobic inert environment with a slight positive pressure inside the reactor, thus cutting off the pathway of spontaneous disordered oxidation of dopamine. The dopamine hydrochloride monomer was prepared into a slightly acidic aqueous solution with a concentration of 10-15 mg / mL, and the pH value was pre-adjusted to 5.0-5.5 to maintain the monomer concentration. To ensure stability, a high-precision multi-channel microfluidic injection pump based on the principle of microelectromechanical systems (MEMS) was used to dropwise add the dopamine monomer solution to the precursor dispersion under vigorous mechanical stirring at an extremely low stray rate of 0.05-0.10 mL / min. The mass ratio of dopamine monomer to graphene oxide in the system was strictly set within an unexpected critical selection range of 1:2.5 to 1:3.2, which could produce a significant synergistic enhancement effect. Under the dual constraints of this critical range and an anaerobic environment, after the dropwise addition was completed, 0.05 mL / min was slowly introduced into the system through a micro-titration device. A 0.15 mol / L sodium periodate aqueous solution, acting as a mild and controllable single-electron transfer oxidant, breaks away from the conventional, high-energy-consuming reaction pathway that relies solely on uncontrolled self-oxidation from free oxygen in the air. After the oxidant is added, a programmed temperature control module is activated, steadily raising the system temperature from 4.5℃ to 28.5℃ at a constant slope of 0.5℃ / min, and maintaining this temperature for 12-16 hours. Under this specific coupling effect of heating kinetics and isothermal thermodynamics, dopamine molecules undergo 5,6-dihydroxylation on the graphene oxide surface. The highly ordered rearrangement, oligomerization, and in-situ crosslinking of indole intermediates covalently graft and self-assemble on the surface of each graphene sheet to form an extremely uniform and dense polydopamine active armor layer. This not only completely eliminates the meaningless generation of a large number of free melanin particles in the aqueous phase in traditional open-cell reactions, but also dramatically increases the effective utilization rate of dopamine raw materials from less than 40% to over 98%. Furthermore, it densely constructs a large number of catechol groups and secondary amine active groups on the surface of two-dimensional graphene sheets, forming a modified graphene oxide suspension with surface-grafted polydopamine.

[0020] Using a graphene oxide suspension with surface-grafted polydopamine as a solid particle emulsifier, environmentally friendly plant-based lubricating oil was subjected to high-speed shear dispersion, and a polyurea resin shell was generated in situ on the surface of the lubricating oil droplets through interfacial polymerization to obtain a surface-armored self-lubricating microcapsule dispersion. In this embodiment, a graphene oxide suspension modified with surface-grafted polydopamine is used as a solid particle emulsifier to perform high-speed shear dispersion of environmentally friendly plant-based lubricating oil. A polyurea resin shell is then formed in situ on the surface of the lubricating oil droplets through interfacial polymerization, resulting in a surface-armored self-lubricating microcapsule dispersion. Molecular reconstruction and interfacial activity enhancement pretreatment of plant-based lubricating oil: Completely abandoning the mineral base oil that produces serious polycyclic aromatic hydrocarbon pollution in traditional track coatings, refined high-oleic sunflower seed oil with biodegradable properties is selected as the core lubricating medium. In order to overcome the technical bottleneck of poor extreme pressure resistance of plant oil, the high-oleic sunflower seed oil is pre-extracted with supercritical carbon dioxide fluid to remove impurities. Under catalyst-free green chemical conditions, it is physically blended with epoxidized soybean oil at a mass ratio of 4:1 to 6:1, and a small amount of ozone is introduced for short-term controlled micro-oxidation treatment, so that the carbon-carbon double bond of the plant oil is converted into epoxy groups and polar peroxide free radicals, thus preparing a modified environmentally friendly plant-based lubricating oil core material. Dynamic construction of Pickering emulsion without surfactant intervention: In a double-layer temperature-controlled reactor with an embedded high-shear emulsifying homogenizer, modified environmentally friendly plant-based lubricating oil core material and isophorone diisocyanate are mixed uniformly at a mass ratio of 10:1 to 15:1 to form an oil phase premix. Discarding any traditional small-molecule chemical surfactants, the prepared surface-grafted polydopamine-modified graphene oxide suspension is directly pumped into the reactor as the only high-molecular solid particle emulsifier. The oil phase premix and suspension are mixed at a volume ratio of 1:4 to 1:6. The high-shear emulsifying homogenizer is started, and high-intensity pulverization and dispersion treatment is carried out for 8-12 minutes using an extremely high shear field that breaks through the conventional emulsification speed limit. Under the strong synergistic effect of extremely high shear force and the amphiphilic properties of polydopamine layer, the modified graphene oxide sheets are arranged at the oil-water interface of the plant oil droplets to form a Pickering oil-in-water primary emulsion system. Asymmetric interfacial polymerization of aqueous and oil phases and construction of biomimetic multilayer armor shells: The primary emulsion system was transferred to an anchor-stirred reactor, and the stirring rate was reduced to a gentle 200-300 rpm. The jacket heating was activated, and the temperature was steadily increased to 65-70℃ at a rate of 1.0℃ / min. At this temperature, isophorone diisocyanate molecules pre-dissolved in the oil phase migrated to the oil-water interface under thermodynamic drive. A 5wt% aqueous solution of polyetheramine and diethylenetriamine, acting as a chain extender, was uniformly added dropwise to the aqueous phase using a metering pump. The primary amine groups in the aqueous phase and the isocyanate groups at the oil-water interface reacted in pure water without the participation of organic solvents. Rapid asymmetric interfacial addition polymerization occurs in the phase environment, and within just 15-30 minutes, a high-crosslink density polyurea resin inner shell layer is generated on the droplet surface through in-situ polycondensation. The unreacted isocyanate groups remaining in the polyurea shell layer will further undergo covalent crosslinking network reaction with the hydroxyl and amine groups on the polydopamine layer on the surface of graphene oxide closely attached to the interface. This causes the two-dimensional nanosheets that were originally physically adsorbed and remained at the interface to be firmly anchored to the outer surface of the polyurea microcapsule through strong chemical bonds, forming a double-layer core-shell structure composed of an inner layer of high-toughness polyurea and an outer layer of high-modulus graphene oxide, thus obtaining a surface-armored self-lubricating microcapsule dispersion.

[0021] Aliphatic diisocyanate and bio-based polycarbonate diol were grafted and polymerized under the action of a catalyst, and a hydrophilic chain extender containing carbon-carbon double bonds was introduced for the reaction. After high-speed phase configuration conversion with deionized water, an aqueous polyurethane prepolymer emulsion containing side group double bonds was prepared. In this embodiment, aliphatic diisocyanate and bio-based polycarbonate diol are grafted and polymerized under the action of a catalyst, and a hydrophilic chain extender containing carbon-carbon double bonds is introduced for the reaction. After high-speed phase configuration conversion with deionized water, an aqueous polyurethane prepolymer emulsion containing side group double bonds is prepared, comprising: Pre-depolymerization and dehydration activation of bio-based raw materials: Bio-based polycarbonate diol with extremely high resistance to UV aging and hydrolysis is used as the soft segment skeleton. The bio-based polycarbonate diol is placed in a three-necked flask with a reflux condenser and subjected to deep dehydration to remove trace small molecule impurities for up to 2 hours under extreme negative pressure and high temperature environment with an absolute pressure of less than 100 Pa and a temperature set at 110-120℃. The moisture content of the system is reduced to an astonishing 0.01 wt%, which eliminates the problem of coating density loss caused by the subsequent reaction of isocyanate groups with water to produce carbon dioxide bubbles from the source. Bulk block copolymerization and hard segment microdomain construction under green catalytic conditions: The dehydrated system is cooled to 75-80℃, and under the protection of high-purity nitrogen, an aliphatic diisocyanate—specifically limited to 4,4'-dicyclohexylmethane diisocyanate with a cyclic structure ratio of more than 80%—is added to impart extreme wear-resistant rigidity to the molecular chain. The molar ratio of isocyanate groups to hydroxyl groups in the system is controlled within the critical value of 1.65 to 1.75. A breakthrough green and non-toxic organic bismuth / zinc composite catalyst is introduced to completely replace the highly toxic organotin catalysts that are strictly controlled by environmental regulations. Under the efficient synergistic catalysis of the green composite catalyst, the reaction proceeds stably for 2-3 hours until the residual NCO group content of the system reaches 98%-102% of the theoretically calculated value as determined by titration, thus completing the synthesis of the polyurethane prepolymer backbone. Precise insertion of double-bond functionalized hydrophilic segments: A specially customized hydrophilic chain extender containing carbon-carbon double bonds is slowly added to the prepolymer. The chain extender is formed by the pre-reaction of dimethylolpropionic acid with hydroxyethyl methacrylate under specific conditions. It not only contains carboxyl groups that can form salts and impart water solubility, but also has highly active methacrylate double bonds suspended on the side chains. The chain extension reaction is carried out at 60-65°C for 1.5 hours. Due to the deliberate reduction of temperature control, the risk of thermal self-polymerization of the side double bonds in the absence of a polymerization inhibitor is avoided. Triethylamine is added as a neutralizing agent, and the degree of neutralization is strictly controlled at 90%-95% of the incompletely neutralized state. Superfluid phase configuration transformation and nano-latex particle solidification: The neutralized functionalized prepolymer was injected at high speed into a high-speed stirred tank containing a large amount of deionized water dispersion medium via a high-pressure micro-jet pump in the form of an extremely fine liquid stream. Under the action of a strong fluid rheological shear stress field, the prepolymer instantly underwent a catastrophic phase configuration reversal from oil-in-water to water-in-oil. The originally coiled molecular chains rapidly self-assembled into nuclei in the aqueous phase, forming highly permeable nano-latex particles with an average particle size of only 40-60 nanometers and a particle size polydispersity index (PDI) of less than 0.1. During this phase transformation process, a secondary chain extension of the aqueous phase with trace amounts of hexamethylenediamine was carried out, and an aqueous polyurethane prepolymer emulsion containing side group double bonds was prepared.

[0022] The surface-armored self-lubricating microcapsule dispersion was added dropwise to an aqueous polyurethane prepolymer emulsion containing side group double bonds for mechanical mixing. Then, by adding a silane coupling agent, the end groups of the aqueous polyurethane prepolymer and the polydopamine layer on the surface of the microcapsules underwent a dehydration condensation reaction to construct molecular-level interfacial crosslinking and obtain an organic-inorganic hybrid coating crosslinking slurry. In this embodiment, a surface-armored self-lubricating microcapsule dispersion is dropwise added to an aqueous polyurethane prepolymer emulsion containing side-group double bonds for mechanical mixing. A silane coupling agent is added to induce a dehydration condensation reaction between the end groups of the aqueous polyurethane prepolymer and the polydopamine layer on the microcapsule surface, constructing a molecular-level interfacial crosslinking to obtain an organic-inorganic hybrid coating crosslinking slurry, comprising: Thixotropic rheological premixing and stabilization of a two-phase dispersion system: Aqueous polyurethane prepolymer emulsion was placed in a high-viscosity reactor with a planetary twin-shaft agitator. The planetary agitator was started at room temperature (20-25℃) with a rotation speed of 40 rpm and a revolution speed of 20 rpm. A pulse peristaltic pump was used to slowly inject the surface-armored self-lubricating microcapsule dispersion into the polyurethane emulsion by pulsed fluid addition. This ensured that the microcapsules were uniformly suspended and embedded in the nanoscale network of the aqueous polyurethane without any physical agglomeration or capsule wall rupture. The mass ratio of the mixture was precisely locked between 12:100 and 18:100 according to the turnout load requirements. The mixture showed an extremely low coefficient of friction in the subsequent friction and wear tests without any compromise in coating adhesion. In-situ directional hydrolysis of silane crosslinking agent and interfacial molecular stitching reaction: After the physical premixed liquid forms a highly uniform suspension, instead of adding conventional silane directly, γ-glycidyl ether propyltrimethoxysilane with epoxy groups is pre-dissolved in a mixed solvent of anhydrous ethanol and weakly acidic water and subjected to strict 30 minutes of room temperature pre-hydrolysis to precisely convert the terminal methoxy group into a highly active silanol group, while retaining the epoxy group at the other end without ring opening. The pre-hydrolyzed KH-560 coupling agent solution is atomized and sprayed into the reaction vessel, and the system temperature is steadily increased to 45-50℃ and stirred for 4-6 hours. The realization of the topological chemical bonding mechanism: Under the mild activation energy of 45-50℃, the silanol groups generated by pre-hydrolysis actively seek the polyphenolic hydroxyl groups enriched on the surface of microcapsules to undergo directional dehydration condensation reaction, forming an indestructible Si-OC covalent bond. The epoxy group at the other end of the silane coupling agent undergoes a ring-opening grafting reaction with the trace amount of amino groups or polar groups in the system that are not completely closed at the molecular chain end of the waterborne polyurethane prepolymer; forming an organic-inorganic hybrid coating crosslinking slurry.

[0023] Organic-inorganic hybrid coating crosslinking slurry was applied to the surface of the pretreated railway turnout substrate and subjected to UV-thermal dual-stage curing treatment. The side double bonds were induced to undergo free radical polymerization by UV light to instantly lock the spatial distribution of microcapsules. The deep condensation reaction of the prepolymer network was completed under the excitation of the heat source, resulting in an environmentally friendly railway turnout coating with a micro-nano multi-level anti-slip and self-healing lubrication network.

[0024] In this embodiment, an organic-inorganic hybrid coating crosslinking slurry is applied to the surface of a pretreated railway turnout substrate, and a dual-stage UV-thermal curing process is performed to obtain an environmentally friendly railway turnout coating with a micro-nano multi-level anti-slip and self-healing lubrication network, comprising: Microtexturing and High-Energy Surface Activation Pretreatment of Turnout Metal Substrates: Completely abandoning traditional high-pollution acid washing and dust-generating sandblasting processes, a high-power nanosecond pulsed fiber laser cleaning system is employed for green dry cleaning and microtexturing treatment of high-manganese steel turnout metal substrates. The laser wavelength is set at 1064nm, the pulse width is 50-100ns, the single-pulse energy density is precisely controlled between 4.5-6.0J / cm², and the scanning speed is 800-1000mm / s. Under this specific strong radiation laser field, not only can the oxide scale and oil stains on the metal surface be vaporized and peeled off at the nanosecond level, producing an absolutely clean bare metal surface, but also… The Marengoni convection effect, caused by the local melting and condensation of the metal surface material, spontaneously etches a biomimetic lotus leaf-like multi-level microtexture morphology with periodic micron-level pits and nano-level ripples with specific topological morphology on the substrate surface. The laser plasma shock wave significantly increases the dislocation density and surface free energy of the surface grains, endowing the substrate with highly aggressive chemical adsorption potential. The above-mentioned organic-inorganic hybrid coating crosslinking slurry is uniformly coated on the microtextured high-energy metal surface with a wet film thickness of 150-200 microns using high-pressure airless spraying technology. The slurry instantly generates a strong capillary wetting effect, deeply anchors and fills all micro-pits, forming an unbreakable mechanical interlocking effect. Photoinduced instantaneous phase locking and UV free radical deep polymerization: To completely solve the fatal defects of traditional thermosetting coatings, such as sagging, craters, and uneven lubrication distribution caused by the thermal agglomeration and floating of microcapsules during the baking process, UV photoinduced instantaneous phase locking technology is introduced. After the workpiece is coated with wet film, it first enters a composite-band UV curing tunnel, with a trace amount of composite photoinitiator introduced in the formula as the excitation point. The tunnel adopts dual-frequency synergistic radiation of UVA and UVC bands, with an radiation time of only 8-12 seconds. UVC strongly penetrates deep to excite free radicals, while UVA dominates surface crosslinking. The UV light instantly triggers an explosive free radical addition in-situ crosslinking polymerization reaction of carbon-carbon double bonds on the side groups of the waterborne polyurethane prepolymer molecular chain. Within a few seconds, the viscosity of the liquid slurry jumps geometrically to a three-dimensional gel state, anchoring all the surface armored self-lubricating microcapsules in situ at every node inside the coating with an absolutely uniform spatial distribution, completely blocking any possibility of thermodynamic migration and sedimentation of fillers. Thermodynamically driven deep condensation and stress relief of molecular networks: The semi-cured coating, after photocuring phase locking, is then subjected to deep, stepped thermocuring in a mid-infrared thermal oven. The heating curve is strictly set as a step: it is held at a low temperature of 60℃ for 20 minutes to slowly and non-destructively drive away residual moisture and trace amounts of polar solvents in the network, avoiding the formation of boiling micropore defects in the system. The temperature is then gently increased to 120℃ at a rate of 2℃ / min and held at the high temperature for 45 minutes. Under the continuous excitation of this deep heat source, the residual NCO groups in the polyurethane skeleton undergo deep chain extension and cross-reaction with moisture or other active hydrogens. At the same time, the condensation network of the silane coupling agent is further matured and densified. The high-temperature curing further relaxes and releases the internal stress accumulated in the coating due to the rapid shrinkage of the photocuring reaction in the early stage, preventing brittle cracking after film formation. After strict control of UV-thermal dual-step curing, an environmentally friendly railway turnout coating is obtained.

[0025] Example 2: In a pilot production batch, the on-site control system recorded an initial concentration of 2.0 mg / mL of graphene oxide precursor in the mixing tank. The operation log showed that the multi-frequency cascaded ultrasonic system completed the automatic switching from a low frequency of 22 kHz to a high frequency of 85 kHz precisely and smoothly within 18 minutes of startup. Simultaneously, continuous sampling data from the jacket temperature control probe showed that the core liquid temperature of the system was locked at 4.3℃ throughout the cavitation dispersion period, without any localized hot spot anomalies commonly seen in routine operations. The microfluidic monitoring module showed that the dopamine monomer solution was continuously added at a precise rate of 0.08 mL / min for 45 minutes, during which time the pressure sensor in the sealed reaction chamber maintained an oxygen-free micro-positive pressure environment of 0.13 MPa. Further online UV-Vis spectroscopy analysis revealed that the absorption peak of free dopamine in the aqueous phase had completely disappeared 14 hours after sodium periodate injection and a programmed, stable temperature rise to 28.5℃. The system automatically triggered sampling, and the offline analysis report from transmission electron microscopy confirmed that a dense polymer coating layer with a thickness of 6.2 nanometers and a thickness distribution deviation of only 4.5% had been uniformly grown on the surface of the graphene sheet. The system determined that the in-situ self-polymerization reaction had reached the preset critical conditions and recorded and output a suspension of modified graphene oxide grafted with polydopamine.

[0026] The production line's fluid delivery network recorded the pumping of 50 liters of plant-based lubricating oil core material, activated by controlled micro-ozone, into a double-layered emulsification reaction chamber. An online torque sensor detected that the high-shear homogenizer reached its maximum speed of 20,500 rpm within 3 seconds of startup and operated under constant load for 10 minutes. During this period of high-intensity shear, continuous cross-sectional data transmitted via a bypass laser particle size analyzer showed that with the introduction of the modified graphene oxide suspension, the system spontaneously reconstructed itself from a macroscopically layered state extremely rapidly. The peak of the average droplet size narrowed rapidly and concentrated at 2.8 micrometers, and the equipment did not report any demulsification warnings, indicating that the physical assembly of the Pickering interface without surfactant participation was completed instantaneously. After the homogenizer speed decreased according to the program, the aqueous chain extender dripping pipeline automatically opened. At the 22-minute mark, the online infrared spectroscopy monitoring probe detected a sharp decay of the isocyanate characteristic peak (2270 cm⁻¹) signal at the oil-water interface to zero, marking the complete end of the interfacial asymmetric polymerization. The material report generated by the system sampling inspection showed that the solid content of the obtained microcapsules was 28.5%, and in the subsequent hydrostatic pressure crack microscopic test, the batch capsule wall withstood an extreme pressure of up to 1150 MPa without structural collapse. The system confirmed the successful preparation of the surface armored self-lubricating microcapsule dispersion with a double core-shell structure, and transferred it to the buffer storage tank.

[0027] On another parallel synthesis line, the pressure gauge of the high-vacuum dehydration equipment continuously displayed a negative pressure environment below 85 Pa for 40 minutes. Simultaneously, the online Karl Fischer moisture titrator alarmed, indicating that the moisture content of the polycarbonate diol had dropped to an extremely low 0.008 wt%, triggering a signal indicating the completion of the dehydration process. After introducing nitrogen and injecting the HMDI monomer and bismuth-zinc composite catalyst, the reaction monitoring system measured the NCO residual rate every 15 minutes using an automatic potentiometric titrator. The dynamic monitoring curve showed that at the 145-minute mark of the isothermal reaction, the residual NCO group amount precisely fell within the extremely narrow window of 99.2% of the theoretically calculated value, triggering a node signal indicating the completion of the prepolymer main chain construction. After the system automatically introduced a double-bond hydrophilic chain extender and completed the incomplete neutralization process, a high-pressure micro-jet pump forcibly injected the material into deionized water at a flow rate of 30 meters per second. The dynamic light scattering probe captured the dramatic rheological abrupt change in phase configuration inversion in real time. The latex particle size data on the monitoring screen stabilized at 48 nm within 1 second, with a polydispersity index as low as 0.06. Continuous data chains confirmed that no macroscopic gelation occurred in the system, resulting in an aqueous polyurethane prepolymer emulsion containing side-group double bonds with extremely high permeability and reactivity.

[0028] After entering the slurry compounding stage, the servo motor's background log recorded that the planetary biaxial high-viscosity reactor strictly maintained a constant thixotropic shear field of 40 rpm rotation and 20 rpm revolution. Within one hour, a fluid pulse pump gradually pumped the microcapsule dispersion into the prepolymer emulsion at a minute pulse rate of 2% of the total volume. The machine vision algorithm of the explosion-proof camera monitoring did not detect any abnormal color patches caused by micro-flocculation or demulsification. The mass flow meter monitored the KH-560 coupling agent, which had undergone 30 minutes of controlled pre-hydrolysis, being vaporized and atomized into the reactor. The system temperature sensor curve rose smoothly and solidified, remaining constant at 48.5℃. After 5 hours of mechanical incubation, the data transmitted online by the rheometer showed a clear rheological inflection point: the thixotropic index of the system steadily increased from the initial 1.2 and stabilized at 4.6, exhibiting extremely excellent anti-sagging potential. Through offline sampling analysis of nuclear magnetic resonance silicon spectroscopy, the researchers clearly observed the unique chemical shift characteristic peaks corresponding to the Si-OC covalent bonds. This crucial microscopic data chain confirms that a molecular-level interfacial crosslinking has been successfully constructed between the inorganic microcapsules and the organic polyurethane matrix. The system successfully outputs and encapsulates an organic-inorganic hybrid coating crosslinking slurry that showed no macroscopic phase separation during centrifugation testing.

[0029] During the on-site coating process and performance monitoring, the implementers observed a handheld 3D laser profilometer scanning the high-manganese steel substrate of the railway turnout after nanosecond pulsed fiber laser cleaning. The data screen displayed real-time data showing a uniform surface roughness of 3.2 micrometers in the treated area. Simultaneously, a portable contact angle meter showed that a water droplet rapidly spread within 0.1 seconds, with the contact angle dropping sharply to 12 degrees. This confirmed the successful formation of a high-energy biomimetic multi-level microtexture. A high-pressure airless spraying terminal uniformly coated the cross-linked slurry onto the substrate surface, and an ultrasonic thickness gauge confirmed a wet film thickness of 185 micrometers. In the critical curing stage, a dual-frequency UV ultraviolet radiation monitoring module detected that the wet film surface was subjected to precise, continuous, and intense light radiation for 10 seconds. An infrared thermal imager showed a tiny, uniform exothermic polymerization peak instantly generated within the liquid film. A coating rheometer showed that the dynamic viscosity increased geometrically after the light exposure ended, transforming into a gel state. Based on this, the system confirmed that the side double bonds had undergone free radical polymerization, completely blocking the physical channels for particle sedimentation. After undergoing deep condensation treatment in an infrared stepped thermal drying tunnel, the coating is finally formed. In the dual-disc rolling friction and wear acceptance test, the torque sensor continuously recorded an extremely smooth dynamic friction coefficient curve for 100 hours, with the value remaining constant at 0.072 without any deterioration or rebound. Simultaneously, the cross-cut peeling and pull-out tester showed that the interfacial tensile strength of the coating exceeded 18 MPa. This series of comprehensive test reports from the system provides closed-loop proof that the system has successfully constructed an environmentally friendly railway turnout coating with a micro-nano multi-level anti-slip and self-healing lubrication network, effectively and sustainably eliminating the threat of turnout wear under extreme pressure mechanical conditions.

[0030] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing an environmentally friendly railway turnout coating, characterized in that, The preparation method includes: Graphene oxide was ultrasonically dispersed in a weakly alkaline buffer solution, and dopamine hydrochloride was added to carry out an in-situ self-polymerization reaction in the dark to grow a polydopamine active adhesion layer on the surface of the graphene oxide sheets, forming a modified graphene oxide suspension with surface-grafted polydopamine. Using a graphene oxide suspension with surface-grafted polydopamine as a solid particle emulsifier, environmentally friendly plant-based lubricating oil was subjected to high-speed shear dispersion, and a polyurea resin shell was generated in situ on the surface of the lubricating oil droplets through interfacial polymerization to obtain a surface-armored self-lubricating microcapsule dispersion. Aliphatic diisocyanate and bio-based polycarbonate diol were grafted and polymerized under the action of a catalyst, and a hydrophilic chain extender containing carbon-carbon double bonds was introduced for the reaction. After high-speed phase configuration conversion with deionized water, an aqueous polyurethane prepolymer emulsion containing side group double bonds was prepared. The surface-armored self-lubricating microcapsule dispersion was added dropwise to the aqueous polyurethane prepolymer emulsion containing side group double bonds for mechanical mixing. The end groups of the aqueous polyurethane prepolymer and the polydopamine layer on the surface of the microcapsules were dehydrated and condensed by adding a silane coupling agent to construct molecular-level interfacial crosslinking and obtain an organic-inorganic hybrid coating crosslinking slurry. Organic-inorganic hybrid coating crosslinking slurry was applied to the surface of the pretreated railway turnout substrate and subjected to UV-thermal dual-stage curing treatment. The side double bonds were induced to undergo free radical polymerization by UV light to instantly lock the spatial distribution of microcapsules. The deep condensation reaction of the prepolymer network was completed under the excitation of the heat source, resulting in an environmentally friendly railway turnout coating with a micro-nano multi-level anti-slip and self-healing lubrication network.

2. The method for preparing an environmentally friendly railway turnout coating according to claim 1, characterized in that, The process involves ultrasonically dispersing graphene oxide in a weakly alkaline buffer solution, adding dopamine hydrochloride to conduct a light-protected in-situ self-polymerization reaction, thereby growing a polydopamine active adhesion layer on the surface of the graphene oxide sheets, forming a polydopamine-grafted modified graphene oxide suspension, comprising: Graphene oxide powder was added to a composite buffer system and dispersed by multi-frequency cascade ultrasonication under strict low-temperature conditions. The active groups were finely exfoliated and retained to obtain a highly active precursor dispersion. In a light-proof and oxygen-free inert environment, dopamine monomer solution was targeted and added dropwise to the highly active precursor dispersion using microfluidic technology to obtain a mixed predispersant containing dopamine monomer. Sodium periodate oxidant was introduced into a mixed pre-dispersion containing dopamine monomers, and programmed temperature rise was performed to drive in-situ self-assembly crosslinking of dopamine to form a modified graphene oxide suspension with surface-grafted polydopamine.

3. The method for preparing an environmentally friendly railway turnout coating according to claim 1, characterized in that, The modified graphene oxide suspension grafted with polydopamine is used as a solid particle emulsifier to perform high-speed shear dispersion of environmentally friendly plant-based lubricating oil, and a polyurea resin shell is generated in situ on the surface of the lubricating oil droplets through interfacial polymerization to obtain a surface-armored self-lubricating microcapsule dispersion, comprising: Plant-based lubricating oil and epoxidized soybean oil were physically blended and then subjected to micro-oxidation activation treatment with ozone to obtain a modified environmentally friendly plant-based lubricating oil core material with spontaneous interface enrichment tendency. A modified environmentally friendly plant-based lubricating oil core material was mixed with isocyanate to form an oil phase, and a high-shear dispersion was performed using a suspension of modified graphene oxide grafted with polydopamine as the sole emulsifier to construct a Pickering primary oil-in-water emulsion. A mixed amine chain extender was added dropwise to the aqueous phase of a primary oil-in-water emulsion in Pickering to drive asymmetric addition polymerization at the oil-water interface, generating a polyurea inner shell in situ and covalently anchoring it to the outer graphene oxide layer, resulting in a surface-armored self-lubricating microcapsule dispersion with a double-core-shell structure.

4. The method for preparing an environmentally friendly railway turnout coating according to claim 1, characterized in that, The process involves grafting aliphatic diisocyanate and bio-based polycarbonate diol under a catalyst, introducing a hydrophilic chain extender containing carbon-carbon double bonds, and then performing a high-speed phase conversion with deionized water to prepare an aqueous polyurethane prepolymer emulsion containing side group double bonds, comprising: Deep dehydration treatment of bio-based polycarbonate diols is performed using extreme negative pressure coupled with high temperature to remove trace amounts of moisture and impurities, resulting in high-purity dehydrated and activated diols. Under the action of a non-toxic composite catalyst, high-purity dehydrated and activated diols and aliphatic diisocyanates are bulk block copolymerized to synthesize the main chain backbone of polyurethane prepolymers. A hydrophilic chain extender containing carbon-carbon double bonds is inserted into the main chain backbone of a polyurethane prepolymer at specific points, and a neutralizing agent is added to perform incomplete neutralization treatment to obtain a functionalized prepolymer with a coiled main chain. Functionalized prepolymers were injected at high speed into deionized water using fluid rheological shear stress to induce phase inversion and complete secondary chain extension in the aqueous phase, thus preparing an aqueous polyurethane prepolymer emulsion containing side group double bonds.

5. The method for preparing an environmentally friendly railway turnout coating according to claim 1, characterized in that, The process involves adding a surface-armored self-lubricating microcapsule dispersion dropwise to the aqueous polyurethane prepolymer emulsion containing side-group double bonds for mechanical mixing. A silane coupling agent is then added to induce a dehydration condensation reaction between the end groups of the aqueous polyurethane prepolymer and the polydopamine layer on the microcapsule surface, constructing a molecular-level interfacial crosslinking layer to obtain an organic-inorganic hybrid coating crosslinking slurry, comprising: Under a planetary biaxial shear force field, a surface-armored self-lubricating microcapsule dispersion is slowly injected into an aqueous polyurethane prepolymer emulsion containing side group double bonds in a fluid pulse manner to obtain a biphase physical premixed suspension in which the microcapsules are uniformly suspended. The silane coupling agent containing epoxy groups is placed in a weakly acidic mixed solvent and pre-hydrolyzed at controlled room temperature to convert it into a pre-hydrolyzed coupling agent containing active silanol groups. The pre-hydrolyzed coupling agent is atomized and added to the biphase physical premixed suspension, and the mixture is heated and stirred at a constant temperature. This drives the two ends of the silane coupling agent to undergo bidirectional topological chemical bonding with the surface of the microcapsule and the end of the prepolymer molecular chain, respectively, thus completely eliminating macroscopic phase separation and obtaining an organic-inorganic hybrid coating crosslinking slurry.

6. The method for preparing an environmentally friendly railway turnout coating according to claim 1, characterized in that, The process involves coating an organic-inorganic hybrid crosslinking slurry onto the surface of a pretreated railway turnout substrate and performing a dual-stage UV-thermal curing process to ultimately form an environmentally friendly railway turnout coating with a micro-nano multi-level anti-slip and self-healing lubrication network. This coating comprises: Nanosecond pulsed fiber lasers were used to perform vaporization stripping and local melting etching on railway turnout metal substrates to obtain multi-level microtextured high-energy metal substrates with significantly enhanced surface energy. Organic-inorganic hybrid coating crosslinking slurry is sprayed under high pressure without air onto the surface of a multi-level microtextured high-energy metal substrate. After capillary wetting and mechanical anchoring, an uncured wet film coating that fills the micro-pits is obtained. Applying dual-frequency synergistic ultraviolet radiation to an uncured wet film coating instantaneously triggers the free radical polymerization of side-chain double bonds, locking the three-dimensional network and microcapsule distribution of the coating, resulting in a photo-induced phase-locked semi-cured coating; A step-by-step heat treatment from low temperature to high temperature is performed on the photo-induced phase-locked semi-cured coating to drive the deep polycondensation of the polyurethane skeleton and silane network and release the internal stress accumulated by photocuring, and finally form a film to obtain an environmentally friendly railway turnout coating.

7. An environmentally friendly railway turnout coating, characterized in that, The coating is prepared by any one of claims 1 to 6.

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