Corrosion-resistant polysilsesquioxane modified polyurethane emulsion and preparation method thereof

Abstract

The invention discloses a corrosion-resistant polysilsesquioxane modified polyurethane emulsion and a preparation method thereof, and belongs to the technical field of emulsions.The preparation method comprises the steps that gamma-aminopropyltriethoxysilane, namely APTES, is subjected to hydrolytic condensation under the catalysis of tetraethylammonium hydroxide, and POSS is prepared; the preparation method comprises the following steps: carrying out hydrolytic condensation reaction on APTES, synchronously adding phenyltrimethoxysilane in the hydrolytic condensation reaction, forming phenyl-amino difunctional POSS (Polyhedral Oligomeric Silsesquioxane) according to a molar ratio of phenyltrimethoxysilane to APTES of 1: 4, and grafting POSS and graphene oxide GO in dimethyl sulfoxide through amidation reaction to prepare a POSS / GO composite material; dispersing POSS / GO / Zn in the polyurethane prepolymer, adding a curing agent and a solvent, and stirring to form a homogeneous emulsion; through phenyl trapezoid polysilsesquioxane modification and dynamic reversible self-repairing network design, the wear resistance of the coating is improved, microcracks can be closed at the temperature of 60 DEG C, and the maintenance requirement is reduced; laser micro-nano structured base material treatment is combined, the adhesive force is increased to be larger than or equal to 20 MPa, and meanwhile a gamma-butyrolactone low-VOC solvent is adopted.

Description

Technical Field

[0001] The present invention relates to the technical field of emulsion, and more specifically, to a corrosion-resistant polyhedral oligomeric silsesquioxane-modified polyurethane emulsion and a preparation method thereof. Background Art

[0002] Due to its excellent mechanical properties, weather resistance and construction convenience, polyurethane emulsion is widely used in the anti-corrosion protection of metals in fields such as ships, bridges, and chemical equipment. To improve the corrosion resistance of the coating, researchers often use graphene oxide (GO) as a reinforcing material, and its lamellar structure can effectively block the penetration of water and oxygen; at the same time, the introduction of polyhedral oligomeric silsesquioxane (POSS) can improve the thermal stability and dispersibility of the coating; In the prior art, preparing POSS by hydrolysis and condensation of silane coupling agents (such as APTES) and grafting it onto the surface of GO, or loading zinc ions as corrosion inhibitors, has become a common means to improve the anti-corrosion performance of polyurethane emulsion. However, such technologies still have the following key problems; However, the GO lamellae are prone to agglomeration due to van der Waals forces, resulting in a decrease in the barrier performance; it is difficult to achieve monolayer exfoliation by traditional mechanical stirring or ultrasonic dispersion, the porosity of the coating > 1%, and medium penetration is likely to occur after long-term immersion; When zinc ions are directly loaded on the surface of GO, the release rate is too fast to achieve long-term corrosion inhibition; and the passivation effect of a single metal corrosion inhibitor (such as Zn²⁺) is limited in a complex corrosion environment (such as high chlorine and high humidity); After the traditional polyurethane coating is damaged, it cannot actively repair microcracks, resulting in the accelerated spread of local corrosion, frequent re-coating is required, and the maintenance cost is high; The grafting of POSS onto GO requires a long-time high-temperature reaction (> 24 hours), with high energy consumption; the solvent system mostly uses acetone or xylene with high VOC (volatile organic compounds), which does not meet the requirements of green manufacturing; Traditional sandblasting or pickling pretreatment is likely to cause uneven microstructures on the substrate surface, the coating adhesion < 15 MPa, and it is prone to peeling after long-term service. Summary of the Invention

[0003] To solve the above problems, the present invention provides a corrosion-resistant polyhedral oligomeric silsesquioxane-modified polyurethane emulsion, and the emulsion is composed of the following components in mass percentages: POSS, i.e., polyhedral oligomeric silsesquioxane-modified graphene oxide GO 0.1% - 5%, zinc ion loading 0.5% - 3%, polyurethane prepolymer 60% - 85%, curing agent 10% - 20%, solvent as the balance, wherein the grafting rate of POSS and GO is 95% - 99%, and zinc ions are loaded on the surface of POSS / GO by electrostatic adsorption; The solvent is a compound system of ethyl acetate and γ-butyrolactone, and the proportion of γ-butyrolactone is 3% - 5%.

[0004] Preferably, a method for preparing a corrosion-resistant polyhedral oligomeric silsesquioxane-modified polyurethane emulsion comprises the following steps: Step 1: Hydrolyze and condense γ-aminopropyltriethoxysilane, i.e., APTES, under the catalysis of tetraethylammonium hydroxide to obtain POSS; During the hydrolysis and condensation reaction, phenyltrimethoxysilane is added synchronously. The molar ratio of phenyltrimethoxysilane to APTES is 1:4 to form phenyl-amino bifunctional POSS; Step 2: Graft POSS and graphene oxide GO in dimethyl sulfoxide through amidation reaction to obtain POSS / GO composite; Step 3: Mix zinc nitrate solution with POSS / GO, react at 60 - 80 °C for 4 - 6 hours, and obtain POSS / GO / Zn composite nanomaterial after centrifugation and drying; Synchronously add lanthanum nitrate solution with a zinc-lanthanum molar ratio of 10:1 to form ZnO-La2O3 heterojunction; Step 4: Disperse POSS / GO / Zn in polyurethane prepolymer, add curing agent and solvent, and stir to form a homogeneous emulsion.

[0005] Preferably, in a method for preparing a corrosion-resistant polyhedral oligomeric silsesquioxane-modified polyurethane emulsion, the temperature of the amidation reaction in Step 2 is 150 - 180 °C, the reaction time is 18 - 24 hours, the mass ratio of POSS to GO is 5:1 to 20:1, and paraformaldehyde is used as a crosslinking agent; 0.1% - 0.5% polyether-modified siloxane is introduced into the crosslinking agent to improve the dispersion of GO sheets.

[0006] Preferably, the concentration of the zinc nitrate solution in Step 3 is 0.1 - 0.5 mol / L, the mass ratio of POSS / GO to zinc nitrate is 1:1 to 1:3, and the zinc ion loading after reaction is 10% - 25%; After the reaction, the ZnO grain size is made uniform to 50 - 100 nm by plasma treatment.

[0007] Preferably, the curing agent is isophorone diisocyanate IPDI or hexamethylene diisocyanate HDI, the solvent is ethyl acetate or acetone, and the solvent accounts for 5% - 15%; 0.5% - 1% photoinitiator TPO-L is introduced into the curing agent to support UV-assisted curing.

[0008] Preferably, a method for preparing a corrosion-resistant polyhedral oligomeric silsesquioxane-modified polyurethane emulsion is applicable to a corrosion-resistant polyhedral oligomeric silsesquioxane-modified polyurethane emulsion prepared as above, and is characterized by comprising the following steps: Spray or brush the emulsion on the surface of the metal substrate, and control the coating thickness to be 80 - 150 μm; Cure at 25 - 40 °C for 24 - 48 hours to form a composite coating with hydrophobicity and corrosion resistance; Pre - treat the substrate with pulsed laser before preparation to form a micro - nano groove structure, and improve the coating adhesion force ≥ 20 MPa.

[0009] Preferably, before spraying, the metal substrate needs to be sand - blasted, with a surface roughness Ra of 1.0 - 2.5 μm, and cleaned with acetone to remove oil stains.

[0010] Preferably, its electrochemical impedance value is not less than 8×10 5 Ω·cm² after soaking in 3.5% NaCl solution for 40 days, the water contact angle is 95° - 110°, and the coating porosity is less than 0.5%; After 1000 - hour thermal aging at 60 °C, the impedance value decay rate < 10%, and the wear - resistance mass loss < 5 mg / 1000 times.

[0011] Preferably, in step four, an ultrasonic dispersion technology is adopted, with an ultrasonic power of 200 - 400 W and a time of 30 - 60 minutes to ensure the uniform dispersion of POSS / GO / Zn in the polyurethane prepolymer; After dispersion, further reduce the aggregate size to D50 < 200 nm through a high - pressure homogenizer.

[0012] Preferably, the microstructure of the POSS / GO / Zn composite nanomaterial is as follows: The GO lamellar spacing expands to 0.74 - 0.80 Å; POSS is embedded in the GO interlayer in a cage - like structure to form steric hindrance; Zinc oxide crystals are distributed on the surface of GO in the form of particles with a particle size of 50 - 200 nm.

[0013] Beneficial effects: Through the modification of phenyl - ladder polysilsesquioxane and the design of a dynamic reversible self - healing network, the wear - resistance of the coating is improved, and micro - cracks can be closed at 60 °C, reducing maintenance requirements; combined with laser micro - nano structured substrate treatment, the adhesion force is increased to ≥ 20 MPa, and at the same time, γ - butyrolactone with low VOC solvent is used. Brief Description of the Drawings

[0014] Figure 1 It is the process flow chart of the present invention. Detailed Embodiments

[0015] As Figure 1 shown: A corrosion - resistant polysilsesquioxane - modified polyurethane emulsion, and the emulsion is composed of the following components in mass percentage: POSS, that is, cage-like silsesquioxane modified graphene oxide GO 0.1% - 5%, zinc ion loading 0.5% - 3%, polyurethane prepolymer 60% - 85%, curing agent 10% - 20%, and the balance is solvent. Among them, the grafting rate of POSS and GO is 95% - 99%, and zinc ions are loaded on the surface of POSS / GO by electrostatic adsorption; The solvent is a compound system of ethyl acetate and γ-butyrolactone, and the proportion of γ-butyrolactone is 3% - 5%. It should be noted that through the modification of GO by POSS and the loading of zinc ions, a synergistic anti-corrosion system is constructed; introducing dynamic reversible bonds (Diels-Alder) to enhance the self-healing ability of the coating, and the grafting structure of POSS / GO (grafting rate ≥ 99%) forms a dense barrier, and the corrosion inhibition effect of zinc ions prolongs the anti-corrosion life; The dynamic bonds can close microcracks at 60 °C, reducing the risk of medium penetration. The compound solvent of ethyl acetate and γ-butyrolactone reduces VOC emissions, which conforms to the trend of green chemical industry;

[0016] As an optional embodiment: The present invention also proposes a preparation method of a corrosion-resistant poly(silsesquioxane) modified polyurethane emulsion, which includes the following steps: Step 1: γ-Aminopropyltriethoxysilane, that is, APTES, is hydrolyzed and condensed under the catalysis of tetraethylammonium hydroxide to obtain POSS; It should be noted that γ-aminopropyltriethoxysilane generates cage-like POSS through hydrolysis and condensation reaction under the catalysis of tetraethylammonium hydroxide; Phenyltrimethoxysilane is synchronously added during the hydrolysis and condensation reaction, and the molar ratio of phenyltrimethoxysilane to APTES is 1:4 to form phenyl-amino bifunctional POSS; Step 2: POSS and graphene oxide GO are grafted in dimethyl sulfoxide through amidation reaction to obtain POSS / GO composite material; It should be noted that the amino group of POSS and the carboxyl group of graphene oxide (GO) form covalent grafting through amidation reaction. Paraformaldehyde is used as a cross-linking agent to promote the dehydration condensation of amino group and carboxyl group, and polyether-modified siloxane improves the dispersion of GO through hydrogen bond interaction; Step 3: Mix zinc nitrate solution with POSS / GO, react at 60 - 80 °C for 4 - 6 hours, and obtain POSS / GO / Zn composite nanomaterial after centrifugation and drying; Synchronously add lanthanum nitrate solution, and the zinc-lanthanum molar ratio is 10:1 to form ZnO-La2O3 heterojunction; Step 4: Disperse POSS / GO / Zn in the polyurethane prepolymer, add the curing agent and the solvent, and stir to form a homogeneous emulsion. It should be noted that through the synthesis of phenyl-amino bifunctional POSS and the optimization of the reaction efficiency by microwave-assisted grafting process, the introduction of phenyl enhances the thermal stability of POSS (Tg is increased to 140 °C), and the amino group promotes the covalent bonding grafting with GO; Microwave radiation shortens the reaction time to 1 hour (traditionally 24 hours), and the grafting rate > 99%; The ZnO-La2O3 heterojunction (zinc to lanthanum ratio of 10:1) passivates the metal surface, and the acid and alkali resistance is increased by 50%; The polyurethane prepolymer is prepared by the polycondensation reaction of isocyanate and polyol. The ureido structure is introduced through the chain extender to enhance the molecular chain rigidity. The photoinitiator TPO-L in the curing agent triggers ultraviolet crosslinking to form a three-dimensional network structure.

[0017] As an optional embodiment: the temperature of the amidation reaction in Step 2 is 150 - 180 °C, the reaction time is 18 - 24 hours, the mass ratio of POSS to GO is 5:1 to 20:1, and paraformaldehyde is used as the crosslinking agent; 0.1% - 0.5% of polyether-modified siloxane is introduced into the crosslinking agent to improve the dispersion of GO sheets.

[0018] It should be noted that the crosslinking agent system is optimized to improve the dispersion of GO and the reaction uniformity. The polyether-modified siloxane reduces the agglomeration of GO sheets, the coating porosity < 0.5%, and paraformaldehyde reacts with the POSS amino group to form a stable covalent network, and the adhesion ≥ 20 MPa; As an optional embodiment: the concentration of the zinc nitrate solution in Step 3 is 0.1 - 0.5 mol / L, the mass ratio of POSS / GO to zinc nitrate is 1:1 to 1:3, and the zinc ion loading after the reaction is 10% - 25%; After the reaction, the ZnO grain size is homogenized to 50 - 100 nm by plasma treatment.

[0019] It should be noted that the ZnO grain size and distribution are regulated by plasma treatment. Plasma treatment makes the ZnO particle size uniform (50 - 100 nm), improves the corrosion inhibition efficiency, and the impedance value after soaking in 3.5% NaCl solution for 40 days > 8×10 5 Ω·cm², which is better than the conventional zinc-based emulsion; As an optional embodiment: the curing agent is isophorone diisocyanate IPDI or hexamethylene diisocyanate HDI, the solvent is ethyl acetate or acetone, and the solvent proportion is 5% - 15%; Introduce 0.5% - 1% photoinitiator TPO-L into the curing agent to support UV-assisted curing. It should be noted that introducing the photoinitiator to achieve UV-assisted curing can improve the construction flexibility. The TPO-L photoinitiator supports ultraviolet light-triggered crosslinking, shortening the curing time by 30%. The IPDI / HDI curing agent forms chemical bonds with the metal substrate, and the peel strength > 15 MPa; As an alternative embodiment: The present invention also proposes a preparation method of a corrosion-resistant polyhedral oligomeric silsesquioxane-modified polyurethane emulsion, which is applicable to a corrosion-resistant polyhedral oligomeric silsesquioxane-modified polyurethane emulsion prepared as described above, and includes the following steps: Spray or brush the emulsion according to any one of claims 1 - 5 on the surface of the metal substrate, and control the coating thickness to be 80 - 150 μm; Cure at 25 - 40 °C for 24 - 48 hours to form a composite coating with hydrophobicity and corrosion resistance; Pre-treat the substrate with pulsed laser before preparation to form a micro-nano groove structure, and improve the coating adhesion force ≥ 20 MPa. It should be noted that the pulsed laser wavelength is 1064 nm, the energy density is 2 J / cm², and the depth of the micro-nano groove structure is 5 - 10 μm; It should also be noted that the coating bonding force is improved by laser micro-nano structuring the substrate. The micro-nano grooves (depth 5 - 10 μm) increase the specific surface area, and the adhesion force is increased to ≥ 20 MPa. The coating after pulsed laser (1064 nm) treatment has no blistering after 720 hours of salt spray test; As an alternative embodiment: The metal substrate needs to be sandblasted before spraying, the surface roughness Ra is 1.0 - 2.5 μm, and acetone is used for cleaning to remove oil stains.

[0020] It should be noted that after sandblasting, silane coupling agent KH-550 is coated, and a transition layer is formed after drying; It should also be noted that a transition layer is formed by combining sandblasting and silane coupling agent to optimize the interface bonding. The sandblasting Ra = 1.0 - 2.5 μm matches the coating thickness, reducing stress concentration. The KH-550 silane layer reacts with the POSS amino group, and the wet heat aging resistance is improved by 30%; As an alternative embodiment: Its electrochemical impedance value is not less than 8×10 5 Ω·cm² after being immersed in 3.5% NaCl solution for 40 days, the water contact angle is 95° - 110°, and the coating porosity is lower than 0.5%; After 1000 hours of thermal aging at 60 °C, the impedance value decay rate < 10%, and the mass loss of abrasion resistance < 5 mg / 1000 times. It should be noted that the long-term stability and mechanical durability of the coating are quantified. After 1000 hours of thermal aging at 60 °C, the impedance decay < 10%, which is applicable to high-temperature environments. The mass loss of Taber wear test < 5 mg / 1000 times, extending the equipment maintenance cycle; As an optional embodiment: in the fourth step, an ultrasonic dispersion technique is adopted, with an ultrasonic power of 200 - 400 W and a time of 30 - 60 minutes to ensure the uniform dispersion of POSS / GO / Zn in the polyurethane prepolymer; After dispersion, a high-pressure homogenizer is used to further reduce the aggregate size to D50 < 200 nm.

[0021] It should be noted that the ultrasonic and high-pressure homogenization are combined to achieve the uniform dispersion of the nanomaterials. High-pressure homogenization (150 MPa) makes the aggregate D50 < 200 nm, improves the coating density, enhances the viscosity stability of the emulsion after homogenization, and is suitable for construction on complex base surfaces; As an optional embodiment: the microstructure of the POSS / GO / Zn composite nanomaterial is as follows: The GO lamellar spacing is extended to 0.74 - 0.80 Å; POSS is embedded in the GO interlayer in a cage structure to form steric hindrance; Zinc oxide crystals are distributed on the surface of GO in the form of particles with a particle size of 50 - 200 nm.

[0022] It should be noted that the relationship between the microscopic characteristics and properties of the POSS / GO / Zn composite material is clarified. The GO lamellar spacing is extended to 0.74 - 0.80 Å, and the efficiency of blocking chloride ion diffusion is increased by 40%. The ZnO crystal (50 - 200 nm) and La2O3 form a double-metal passivation film, and the acid corrosion resistance is > 5 years; The following is a further description according to specific embodiments: Example 1: Step 1: Mix γ-aminopropyltriethoxysilane (APTES) and phenyltrimethoxysilane (molar ratio 4:1), and carry out hydrolysis and condensation at 80 °C for 24 hours under the catalysis of tetraethylammonium hydroxide to obtain phenyl-amino bifunctional POSS; Step 2: Add POSS and graphene oxide (mass ratio 10:1) to dimethyl sulfoxide, add 0.3% polyether-modified silicone crosslinking agent, and carry out microwave-assisted reaction (power 300 W, 1 hour) to obtain a POSS / GO composite material with a grafting rate of 99%; Step 3: Mix 0.3 mol / L zinc nitrate solution with POSS / GO (mass ratio 1:2), add lanthanum nitrate (zinc-lanthanum molar ratio 10:1), react at 70 °C for 5 hours, and obtain a ZnO-La2O3 heterojunction composite nanomaterial (ZnO particle size 50 - 100 nm) after plasma treatment; Step 4: Disperse POSS / GO / Zn (mass ratio 3%) in a polyurethane prepolymer containing 6% dynamic reversible bonds, add IPDI curing agent (ratio 15%) and a mixed solvent (ethyl acetate: γ-butyrolactone = 95:5), perform ultrasonic dispersion (power 300 W, 40 minutes), and then conduct high-pressure homogenization (150 MPa) treatment to obtain an emulsion; Preparation method based on this: Sandblast the metal substrate (Ra = 1.5 μm) and coat it with KH-550 silane coupling agent; Perform pulsed laser pretreatment (wavelength 1064 nm, energy density 2 J / cm²) to form micro-nano grooves; Spray the emulsion to a thickness of 100 μm, and perform UV-assisted curing (containing 0.5% TPO-L photoinitiator), and cure at 40 °C for 30 hours.

[0023] Example 2: Step 1: Adjust the molar ratio of APTES to phenyltrimethoxysilane to 3:1, and the rest is the same as in Example 1; Step 3: Increase the concentration of zinc nitrate solution to 0.5 mol / L and change the zinc-lanthanum molar ratio to 8:1; Step 4: Increase the mass ratio of POSS / GO / Zn to 5% and increase the dynamic bond content to 8%; Preparation method: Increase the coating thickness to 150 μm and extend the curing time to 48 hours.

[0024] Example 3: Step 2: Cancel the microwave-assisted reaction and change it to conventional heating (180 °C, 24 hours), and the grafting rate drops to 95%; Step 3: Do not add lanthanum nitrate and only load pure ZnO; Step 4: Change the solvent to pure ethyl acetate and do not use γ-butyrolactone; Perform performance tests on the mosquito and fly attractant compositions prepared in the above examples. The test results are shown in the following table: For Example 1 vs Example 2: Optimization of the zinc-lanthanum ratio and increase in the dynamic bond content increase the impedance by 8%, but the too-thick coating causes slight discoloration in the salt spray test; Example 1 vs Example 3: The traditional process and the non-addition of lanthanum result in a 63% decrease in impedance and a 3-fold increase in porosity, verifying the necessity of microwave assistance and heterojunction.

[0025] The above are only the preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, several improvements and refinements made without departing from the principle of the present invention should also be regarded as within the protection scope of this template.

Claims

1. A corrosion-resistant polyhedral oligomeric silsesquioxane modified polyurethane emulsion, characterized in that, The emulsion consists of the following components by mass percentage: POSS, i.e., cage-like octasilsesquioxane modified graphene oxide GO 0.1% - 5%, zinc ion loading 0.5% - 3%, polyurethane prepolymer 60% - 85%, curing agent 10% - 20%, solvent in the balance, wherein the grafting rate of POSS and GO is 95% - 99%, and zinc ions are loaded on the surface of POSS / GO by electrostatic adsorption; The solvent is a complex system of ethyl acetate and γ-butyrolactone, and the proportion of γ-butyrolactone is 3% - 5%.

2. The preparation method of a corrosion-resistant polyhedral oligomeric silsesquioxane modified polyurethane emulsion according to claim 1, characterized in that, It includes the following steps: Step 1: γ-Aminopropyltriethoxysilane, i.e., APTES, is hydrolyzed and condensed under the catalysis of tetraethylammonium hydroxide to obtain POSS, i.e., polyhedral oligomeric silsesquioxane; Phenyltrimethoxysilane is synchronously added during the hydrolysis and condensation reaction, and the molar ratio of phenyltrimethoxysilane to APTES is 1:4 to form phenyl-amino bifunctional POSS; Step 2: POSS and graphene oxide GO are grafted in dimethyl sulfoxide through amidation reaction to obtain POSS / GO composite material; Step 3: Zinc nitrate solution and POSS / GO are mixed, and reacted at 60 - 80 °C for 4 - 6 hours, and after centrifugation and drying, POSS / GO / Zn composite nanomaterial is obtained; Lanthanum nitrate solution is synchronously added, and the zinc-lanthanum molar ratio is 10:1 to form ZnO-La2O3 heterojunction; Step 4: POSS / GO / Zn is dispersed in polyurethane prepolymer, and curing agent and solvent are added, and stirred to form a homogeneous emulsion.

3. The preparation method of a corrosion-resistant polyhedral oligomeric silsesquioxane modified polyurethane emulsion according to claim 2, characterized in that, The temperature of the amidation reaction in Step 2 is 150 - 180 °C, the reaction time is 18 - 24 hours, the mass ratio of POSS to GO is 5:1 to 20:1, and paraformaldehyde is used as a cross-linking agent; 0.1% - 0.5% of polyether-modified siloxane is introduced into the cross-linking agent to improve the dispersion of GO sheets.

4. The preparation method of a corrosion-resistant polyhedral oligomeric silsesquioxane modified polyurethane emulsion according to claim 2, characterized in that, The concentration of the zinc nitrate solution in Step 3 is 0.1 - 0.5 mol / L, the mass ratio of POSS / GO to zinc nitrate is 1:1 to 1:3, and the zinc ion loading after reaction is 10% - 25%; After the reaction, the ZnO grain size is homogenized to 50 - 100 nm by plasma treatment.

5. The preparation method of a corrosion-resistant polyhedral oligomeric silsesquioxane-modified polyurethane emulsion according to claim 1, characterized in that, The curing agent is isophorone diisocyanate IPDI or hexamethylene diisocyanate HDI, and the solvent is ethyl acetate or acetone, and the solvent proportion is 5% - 15%; 0.5% - 1% of photoinitiator TPO-L is introduced into the curing agent to support UV-assisted curing.

6. A preparation method of a corrosion-resistant polyhedral oligomeric silsesquioxane modified polyurethane emulsion, applicable to a corrosion-resistant polyhedral oligomeric silsesquioxane modified polyurethane emulsion prepared according to Claims 1 to 5, characterized in that, It includes the following steps: The emulsion described in any one of Claims 1 - 5 is sprayed or brushed on the surface of a metal substrate, and the coating thickness is controlled to be 80 - 150 μm; It is cured at 25 - 40 °C for 24 - 48 hours to form a composite coating with hydrophobicity and corrosion resistance; Before preparation, the substrate is pretreated by pulsed laser to form a micro-nano groove structure to improve the coating adhesion ≥20 MPa.

7. The preparation method of a corrosion-resistant polyhedral oligomeric silsesquioxane modified polyurethane emulsion according to claim 6, characterized in that, Before spraying, the metal substrate needs to be sandblasted, the surface roughness Ra is 1.0 - 2.5 μm, and acetone is used for cleaning to remove oil stains.

8. The corrosion-resistant polyhedral oligomeric silsesquioxane modified polyurethane emulsion according to claim 1, characterized in that, Its electrochemical impedance value is not less than 8×10 5 Ω·cm² after being immersed in 3.5% NaCl solution for 40 days, the water contact angle is 95°-110°, and the coating porosity is less than 0.5%; After 1000 hours of thermal aging at 60 °C, the impedance value decay rate < 10%, and the wear resistance mass loss < 5 mg / 1000 times.

9. The preparation method of a corrosion-resistant polyhedral oligomeric silsesquioxane-modified polyurethane emulsion according to claim 2, characterized in that, In the fourth step, an ultrasonic dispersion technique is adopted, with an ultrasonic power of 200-400 W and a time of 30-60 minutes to ensure the uniform dispersion of POSS / GO / Zn in the polyurethane prepolymer; After dispersion, a high-pressure homogenizer is used to further reduce the aggregate size to D50 < 200 nm.

10. A corrosion-resistant polyhedral oligomeric silsesquioxane modified polyurethane emulsion according to claim 1, characterized in that, The microstructure of the POSS / GO / Zn composite nanomaterial is as follows: The interlayer spacing of GO is expanded to 0.74-0.80 Å; POSS is embedded in the interlayer of GO in a cage-like structure, forming steric hindrance; Zinc oxide crystals are distributed on the surface of GO in the form of particles with a particle size of 50-200 nm.

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