A highly hydrophobic composite anti-icing coating

Abstract

The present invention relates to the field of anti-icing coatings, and in particular to a highly hydrophobic composite anti-icing coating, comprising the following raw materials in parts by weight: 65-75 parts of a block polymer, 5-8 parts of a photothermal filler, 4-6 parts of hydrophobic nano-silica, 8-10 parts of an isocyanate curing agent, 0.5-1.2 parts of a defoaming agent, 0.8-1.4 parts of a leveling agent, and 15-18 parts of ethyl acetate. The block polymer having a fluorosilicon segment is prepared by an atom transfer radical polymerization method, and the block polymer is used as a matrix resin, and a photothermal filler wrapped in polydopamine is added. This solves the problems of poor weather resistance of the anti-icing coating and poor compatibility of the photothermal filler with the matrix resin, and the anti-icing coating has a good photothermal effect, thereby achieving a good anti-icing effect.

Description

Technical Field

[0001] The present invention relates to the field of anti-icing coatings, and in particular to a highly hydrophobic composite anti-icing coating. Background Art

[0002] In cold and humid climates, liquids on the surface of power transmission towers are prone to condensation, ice and accumulation. Severe icing can cause power transmission towers to break and collapse. Traditional anti-icing technologies, such as electric heating ice melting and chemical deicing spraying, have defects such as high energy consumption, environmental pollution and high maintenance costs. Passive anti-icing coatings have become a research hotspot due to their long-term and low energy consumption advantages. Currently commonly used anti-icing coatings, such as fluorocarbon resins, have strong hydrophobicity, but poor mechanical durability. They are prone to microstructural collapse under low-temperature impact or ultraviolet radiation, resulting in a decrease in their hydrophobicity and a shorter service life. At the same time, in order to improve the performance of anti-icing coatings, fillers with photothermal effects are usually added to the matrix. However, due to the general poor compatibility between photothermal fillers and matrix resins, it is very easy to cause the density and weather resistance of the coating to further decrease, thereby affecting its anti-icing effect and failing to meet market demand. Summary of the Invention

[0003] The purpose of the present invention is to provide a highly hydrophobic composite anti-icing coating. A block polymer with fluorosilicone chain segments is prepared by atom transfer radical polymerization, and is used as a matrix resin. At the same time, a photothermal filler wrapped with polydopamine is added, thereby solving the problems of poor weather resistance of the anti-icing coating and poor compatibility of the photothermal filler with the matrix resin. The coating has a good photothermal effect, thereby achieving a better anti-icing effect.

[0004] The purpose of the present invention can be achieved by the following technical solution: a highly hydrophobic composite anti-icing coating, which comprises the following raw materials in parts by weight: 65-75 parts of block polymer, 5-8 parts of photothermal filler, 4-6 parts of hydrophobic nano-silica, 8-10 parts of isocyanate curing agent, 0.5-1.2 parts of defoaming agent, 0.8-1.4 parts of leveling agent and 15-18 parts of ethyl acetate;

[0005] The hydrophobic nano-silica is Degussa R812;

[0006] The isocyanate curing agent is Covestro N3390;

[0007] The defoamer is BYK-024;

[0008] The leveling agent is BYK-333.

[0009] A method for preparing a highly hydrophobic composite anti-icing coating comprises the following steps: mixing a block polymer, a photothermal filler, hydrophobic nano-silica, a defoamer, a leveling agent and ethyl acetate, stirring for 20-25 minutes, adding an isocyanate curing agent, and continuing to stir for 3-5 minutes to obtain a highly hydrophobic composite anti-icing coating.

[0010] The block polymer is prepared by the following steps:

[0011] Step A1: octamethylcyclotetrasiloxane, 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane, n-butyl lithium, and tetrahydrofuran are mixed, stirred at a rate of 120-140 rpm and a temperature of 0-2° C., reacted for 2-2.5 hours, then dimethylchlorosilane is added, the reaction is continued for 12 hours, centrifuged, distilled under reduced pressure, washed, and dried to obtain a hydrogen-terminated fluorinated siloxane;

[0012] The ratio of octamethylcyclotetrasiloxane, 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane, n-butyl lithium, tetrahydrofuran and dimethylchlorosilane is 2.7-2.8 g: 4.5-4.8 g: 0.52-0.55 g: 15-20 mL: 0.85-0.9 g;

[0013] During the reaction, octamethylcyclotetrasiloxane and 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane first undergo ring-opening polymerization in tetrahydrofuran using n-butyl lithium as a catalyst, and then dimethylchlorosilane is added for end-capping to prepare hydrogen-terminated fluorinated siloxane.

[0014] Step A2: Mixing a hydrogen-terminated fluorosiloxane, allyl alcohol, a Custer catalyst, and tetrahydrofuran, reacting for 4-6 hours at a stirring rate of 180-240 rpm and a temperature of 60° C., rotary evaporation, precipitation with methanol aqueous solution, and drying to obtain a hydroxy-terminated fluorosiloxane. Mixing a hydroxy-terminated fluorosiloxane, 4-dimethylaminopyridine, triethylamine, and tetrahydrofuran, stirring at a stirring rate of 180-240 rpm and a temperature of 0-5° C., stirring, and adding 2-bromo-2-methylpropionyl bromide, reacting for 30-40 minutes, then heating to room temperature, continuing the reaction for 8-10 hours, rotary evaporation, washing with water, and drying to obtain a modified siloxane;

[0015] The volume fraction of methanol-water solution is 75%, the amount ratio of hydrogen-terminated fluorosiloxane, allyl alcohol, Custer catalyst and tetrahydrofuran is 5.2-5.4 g: 0.08-0.1 mL: 0.02-0.024 mL: 25-30 mL; the amount ratio of hydroxyl-terminated fluorosiloxane, 4-dimethylaminopyridine, triethylamine, tetrahydrofuran and 2-bromo-2-methylpropionyl bromide is 3.8-4.2 g: 0.06-0.062 g: 0.28-0.3 mL: 25-30 mL: 0.15-0.18 mL;

[0016] During the reaction, under the action of Custer's catalyst, the terminal hydrogen in the hydrogen-terminated fluorosiloxane reacts with the double bond in allyl alcohol to undergo a hydrosilylation reaction, thereby producing a hydroxyl-terminated fluorosiloxane. Then, under the conditions of 4-dimethylaminopyridine and triethylamine, the hydroxyl group in the hydroxyl-terminated fluorosiloxane reacts with 2-bromo-2-methylpropionyl bromide to produce a modified siloxane.

[0017] Step A3: Methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, modified siloxane, pentamethyldiethylenetriamine, cuprous chloride, and cyclohexanone were mixed, and the mixture was reacted under argon protection at a stirring rate of 140-180 rpm and a temperature of 70-72° C. for 20-24 hours. The mixture was rotary evaporated, dissolved in tetrahydrofuran, filtered through a column, precipitated with methanol, and dried in vacuo to obtain a block polymer.

[0018] The usage ratio of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, modified silicone, pentamethyldiethylenetriamine, cuprous chloride and cyclohexanone is 5.6-5.8 g: 3.2-3.5 g: 1.2-1.4 g: 2.4-2.6 g: 0.08-0.09 mL: 0.05-0.06 g: 25-30 mL;

[0019] During the reaction process, a modified siloxane containing a 2-bromo-2-methylpropionyl bromide structure is used as a macromolecular initiator. Under the action of pentamethyldiethylenetriamine and cuprous chloride, it reacts with the double bonds in methyl methacrylate, butyl acrylate and hydroxyethyl methacrylate through an atom transfer radical polymerization method to prepare a block polymer.

[0020] The photothermal filler is prepared by the following steps:

[0021] Step B1: Graphite phase carbon nitride and ethanol are mixed and ultrasonically dispersed for 15-20 minutes. At a stirring rate of 120-140 rpm and room temperature, an ammonia solution and tetrabutyl titanate are added and stirred for 30-40 minutes. The mixture is then hydrothermally reacted at a temperature of 42-45°C for 20-22 hours. The mixture is cooled, centrifuged, washed with water, dried, and ground to obtain Precursor 1. Precursor 1 is mixed with sodium borohydride, ground in a mortar for 5-8 minutes, and then placed in a tube furnace under nitrogen protection at 300°C for 2 hours to obtain Precursor 2.

[0022] The mass fraction of ammonia solution is 25%, the amount ratio of graphite phase carbon nitride, ethanol, ammonia solution and tetrabutyl titanate is 0.2-0.24g:160-180mL:0.95-1.1mL:1.8-1.9mL; the amount ratio of precursor 1 and sodium borohydride is 0.18-0.2g:0.09-0.1g;

[0023] The graphite phase carbon nitride is Xianfeng Nano XFI10;

[0024] During the reaction, titanium dioxide particles are generated in graphite-phase carbon nitride sheets through a low-temperature hydrothermal method, and a heterojunction is formed between titanium dioxide particles and the graphite-phase carbon nitride, thereby producing precursor 1. Then, under the action of sodium borohydride, the titanium dioxide in precursor 1 is reduced, thereby forming oxygen vacancies and defect sites, thereby producing precursor 2.

[0025] Step B2: thiourea and dimethylacetamide are mixed and ultrasonically dispersed for 15-20 minutes, and then, at a stirring rate of 180-240 rpm and a temperature of room temperature, the precursor 2 and the ethanol solution are stirred and added, and stirred for 40-60 minutes. Then, in a reactor, the temperature is 180-185°C and the reaction is carried out for 10-12 hours to obtain a precursor 3. The precursor 3 is mixed with a Tris-HCl buffer and ultrasonically dispersed for 15-20 minutes. At a temperature of 10-15°C, the dopamine hydrochloride solution is stirred and added, and the reaction is carried out for 20-25 minutes to obtain a photothermal filler;

[0026] The volume fraction of the ethanol solution is 70%, and the dosage ratio of thiourea, dimethylacetamide, precursor 2, and ethanol solution is 0.045-0.05 g: 8-10 mL: 0.05-0.055 g: 18-22 mL; the mass concentration of Tris-HCl buffer is 1.6 g / L, pH=8.5, the molar concentration of dopamine hydrochloride solution is 0.05 mol / L, and the dosage ratio of precursor 3, Tris-HCl buffer, and dopamine hydrochloride solution is 0.048-0.052 g: 12-14 mL: 0.65-0.7 mL;

[0027] During the reaction, since precursor 2 contains titanium dioxide with oxygen vacancies and defect sites, it is doped with thiourea as a nitrogen source and a sulfur source to obtain precursor 3. Then, in Tris-HCl buffer, dopamine is polymerized on the surface of precursor 3 to form a polydopamine layer to obtain a photothermal filler.

[0028] Beneficial effects of the present invention: The present invention discloses a highly hydrophobic composite anti-icing coating, which uses an atom transfer radical polymerization method to prepare a block polymer with a fluorosilicone chain segment, uses the block polymer as a matrix resin, and simultaneously adds a photothermal filler wrapped with polydopamine, thereby solving the problems of poor weather resistance of the anti-icing coating and poor compatibility of the photothermal filler with the matrix resin. The anti-icing coating has a good photothermal effect, thereby achieving a good anti-icing effect.

[0029] Since the block polymer is obtained by the reaction of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate and modified silicone through the atom transfer radical polymerization method, it exhibits a certain gradient distribution, which makes the anti-icing coating exhibit more excellent hydrophobicity and weather resistance. Due to the introduction of photothermal fillers, since its surface is wrapped with polydopamine, the photothermal fillers can react with isocyanate curing agents, thereby avoiding the problem of poor compatibility between the photothermal fillers and the matrix resin, and further improving the mechanical properties of the anti-icing coating. Since the photothermal filler itself is based on graphite phase carbon nitride, and titanium dioxide is generated on the surface by low-temperature hydrothermal method, and then reduced and doped, its multi-step modification effectively improves the photothermal conversion efficiency of the photothermal filler, thereby further improving the anti-icing performance of the coating. To a certain extent, it also reduces the damage to the coating performance caused by ultraviolet radiation and improves the weather resistance of the coating. DETAILED DESCRIPTION

[0030] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0031] Example 1 A highly hydrophobic composite anti-icing coating comprises the following raw materials in parts by weight: 65 parts of a block polymer, 5 parts of a photothermal filler, 4 parts of hydrophobic nano-silica, 8 parts of an isocyanate curing agent, 1.2 parts of a defoaming agent, 0.8 parts of a leveling agent, and 15 parts of ethyl acetate;

[0032] The hydrophobic nano-silica is Degussa R812;

[0033] The isocyanate curing agent is Covestro N3390;

[0034] The defoamer is BYK-024;

[0035] The leveling agent is BYK-333.

[0036] A method for preparing a highly hydrophobic composite anti-icing coating comprises the following steps: mixing a block polymer, a photothermal filler, hydrophobic nano-silica, a defoamer, a leveling agent, and ethyl acetate; stirring for 20 minutes; adding an isocyanate curing agent; and continuing to stir for 5 minutes to obtain a highly hydrophobic composite anti-icing coating.

[0037] The block polymer is prepared by the following steps:

[0038] Step A1: Octamethylcyclotetrasiloxane, 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane, n-butyl lithium, and tetrahydrofuran were mixed, stirred at 120 rpm and 0°C for 2 h, and then dimethylchlorosilane was added. The reaction was continued for 12 h, centrifuged, distilled under reduced pressure, washed, and dried to obtain a hydrogen-terminated fluorinated siloxane.

[0039] The ratio of octamethylcyclotetrasiloxane, 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane, n-butyl lithium, tetrahydrofuran and dimethylchlorosilane is 2.7 g:4.5 g:0.52 g:15 mL:0.85 g;

[0040] Step A2: mixing a hydrogen-terminated fluorosiloxane, allyl alcohol, a Custer catalyst, and tetrahydrofuran, reacting for 4 hours at a stirring rate of 180 rpm and a temperature of 60°C, rotary evaporation, precipitation with methanol aqueous solution, and drying to obtain a hydroxy-terminated fluorosiloxane; mixing a hydroxy-terminated fluorosiloxane, 4-dimethylaminopyridine, triethylamine, and tetrahydrofuran, stirring at a stirring rate of 180 rpm and a temperature of 0°C under nitrogen protection, stirring, and adding 2-bromo-2-methylpropionyl bromide, reacting for 30 minutes, then heating to room temperature, continuing the reaction for 8 hours, rotary evaporation, washing with water, and drying to obtain a modified siloxane;

[0041] The volume fraction of methanol-water solution is 75%, the amount ratio of hydrogen-terminated fluorosiloxane, allyl alcohol, Custer catalyst and tetrahydrofuran is 5.2g:0.08mL:0.02mL:25mL; the amount ratio of hydroxyl-terminated fluorosiloxane, 4-dimethylaminopyridine, triethylamine, tetrahydrofuran and 2-bromo-2-methylpropionyl bromide is 3.8g:0.06g:0.28mL:25mL:0.15mL;

[0042] Step A3: Methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, modified siloxane, pentamethyldiethylenetriamine, cuprous chloride, and cyclohexanone were mixed, stirred at 140 rpm, and reacted at 70° C. under argon protection for 20 h. The mixture was then rotary evaporated, dissolved in tetrahydrofuran, filtered through a column, precipitated with methanol, and dried in vacuo to obtain a block polymer.

[0043] The usage ratio of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, modified silicone, pentamethyldiethylenetriamine, cuprous chloride and cyclohexanone is 5.6 g: 3.2 g: 1.2 g: 2.4 g: 0.08 mL: 0.05 g: 25 mL;

[0044] The photothermal filler is prepared by the following steps:

[0045] Step B1: Graphitic carbon nitride and ethanol were mixed and ultrasonically dispersed for 20 minutes. Ammonia solution and tetrabutyl titanate were added with stirring at a stirring rate of 120 rpm at room temperature and stirred for 40 minutes. The mixture was then hydrothermally reacted at 42°C for 22 hours. The mixture was cooled, centrifuged, washed with water, dried, and ground to obtain Precursor 1. Precursor 1 was mixed with sodium borohydride, ground in a mortar for 5 minutes, and then placed in a tube furnace under nitrogen protection at 300°C for 2 hours to obtain Precursor 2.

[0046] The mass fraction of ammonia solution is 25%, the amount ratio of graphite carbon nitride, ethanol, ammonia solution and tetrabutyl titanate is 0.24g:160mL:1.1mL:1.8mL; the amount ratio of precursor 1 and sodium borohydride is 0.18g:0.1g;

[0047] The graphite phase carbon nitride is Xianfeng Nano XFI10;

[0048] Step B2: thiourea and dimethylacetamide were mixed and ultrasonically dispersed for 20 minutes, and then the precursor 2 and the ethanol solution were added under stirring at a stirring rate of 180 rpm and a temperature of room temperature, and stirred for 60 minutes. Then, the mixture was reacted in a reactor at a temperature of 180°C for 12 hours to obtain the precursor 3. The precursor 3 was mixed with Tris-HCl buffer and ultrasonically dispersed for 15 minutes. At a temperature of 10°C, dopamine hydrochloride solution was added under stirring and reacted for 25 minutes to obtain the photothermal filler.

[0049] The volume fraction of the ethanol solution is 70%, and the usage ratio of thiourea, dimethylacetamide, precursor 2 and ethanol solution is 0.05 g:8 mL:0.05 g:18 mL; the mass concentration of Tris-HCl buffer is 1.6 g / L, pH=8.5, the molar concentration of dopamine hydrochloride solution is 0.05 mol / L, and the usage ratio of precursor 3, Tris-HCl buffer and dopamine hydrochloride solution is 0.052 g:12 mL:0.7 mL.

[0050] Example 2 A highly hydrophobic composite anti-icing coating comprises the following raw materials in parts by weight: 65 parts of a block polymer, 8 parts of a photothermal filler, 6 parts of hydrophobic nano-silica, 10 parts of an isocyanate curing agent, 0.5 parts of a defoaming agent, 0.8 parts of a leveling agent, and 15 parts of ethyl acetate;

[0051] The hydrophobic nano-silica is Degussa R812;

[0052] The isocyanate curing agent is Covestro N3390;

[0053] The defoamer is BYK-024;

[0054] The leveling agent is BYK-333.

[0055] A method for preparing a highly hydrophobic composite anti-icing coating comprises the following steps: mixing a block polymer, a photothermal filler, hydrophobic nano-silica, a defoamer, a leveling agent, and ethyl acetate; stirring for 25 minutes; adding an isocyanate curing agent; and continuing to stir for 3 minutes to obtain a highly hydrophobic composite anti-icing coating.

[0056] The block polymer is prepared by the following steps:

[0057] Step A1: Octamethylcyclotetrasiloxane, 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane, n-butyl lithium, and tetrahydrofuran were mixed, stirred at 140 rpm and 2°C for 2 h, and then dimethylchlorosilane was added. The reaction was continued for 12 h, centrifuged, distilled under reduced pressure, washed, and dried to obtain a hydrogen-terminated fluorinated siloxane.

[0058] The ratio of octamethylcyclotetrasiloxane, 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane, n-butyl lithium, tetrahydrofuran and dimethylchlorosilane is 2.7 g:4.5 g:0.55 g:20 mL:0.85 g;

[0059] Step A2: mixing a hydrogen-terminated fluorosiloxane, allyl alcohol, a Custer catalyst, and tetrahydrofuran, reacting for 4 hours at a stirring rate of 240 rpm and a temperature of 60°C, rotary evaporation, precipitation with methanol aqueous solution, and drying to obtain a hydroxy-terminated fluorosiloxane; mixing a hydroxy-terminated fluorosiloxane, 4-dimethylaminopyridine, triethylamine, and tetrahydrofuran, stirring at a stirring rate of 180 rpm and a temperature of 5°C under nitrogen protection, stirring, and adding 2-bromo-2-methylpropionyl bromide, reacting for 30 minutes, then heating to room temperature, continuing the reaction for 10 hours, rotary evaporation, washing with water, and drying to obtain a modified siloxane;

[0060] The volume fraction of methanol-water solution is 75%, the amount ratio of hydrogen-terminated fluorosiloxane, allyl alcohol, Custer catalyst and tetrahydrofuran is 5.2g:0.08mL:0.024mL:25mL; the amount ratio of hydroxyl-terminated fluorosiloxane, 4-dimethylaminopyridine, triethylamine, tetrahydrofuran and 2-bromo-2-methylpropionyl bromide is 3.8g:0.062g:0.3mL:25mL:0.18mL;

[0061] Step A3: Methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, modified siloxane, pentamethyldiethylenetriamine, cuprous chloride, and cyclohexanone were mixed, stirred at 180 rpm, and reacted at 70° C. under argon protection for 24 h. The mixture was rotary evaporated, dissolved in tetrahydrofuran, filtered through a column, precipitated with methanol, and dried in vacuo to obtain a block polymer.

[0062] The usage ratio of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, modified silicone, pentamethyldiethylenetriamine, cuprous chloride and cyclohexanone is 5.8 g: 3.2 g: 1.4 g: 2.4 g: 0.09 mL: 0.05 g: 30 mL;

[0063] The photothermal filler is prepared by the following steps:

[0064] Step B1: Graphitic carbon nitride and ethanol were mixed and ultrasonically dispersed for 15 minutes. Ammonia solution and tetrabutyl titanate were added with stirring at a stirring rate of 120 rpm at room temperature and stirred for 30 minutes. The mixture was hydrothermally reacted at 42°C for 20 hours. The mixture was cooled, centrifuged, washed with water, dried, and ground to obtain Precursor 1. Precursor 1 was mixed with sodium borohydride, ground in a mortar for 5 minutes, and then placed in a tube furnace under nitrogen protection at 300°C for 2 hours to obtain Precursor 2.

[0065] The mass fraction of ammonia solution is 25%, the amount ratio of graphite carbon nitride, ethanol, ammonia solution and tetrabutyl titanate is 0.2g:160mL:0.95mL:1.8mL; the amount ratio of precursor 1 and sodium borohydride is 0.18g:0.09g;

[0066] The graphite phase carbon nitride is Xianfeng Nano XFI10;

[0067] Step B2: thiourea and dimethylacetamide were mixed and ultrasonically dispersed for 15 minutes, and then the precursor 2 and the ethanol solution were added under stirring at a stirring rate of 180 rpm and a temperature of room temperature, and stirred for 40 minutes. Then, the mixture was reacted in a reactor at a temperature of 180°C for 10 hours to obtain the precursor 3. The precursor 3 was mixed with Tris-HCl buffer and ultrasonically dispersed for 15 minutes. At a temperature of 10°C, dopamine hydrochloride solution was added under stirring and reacted for 20 minutes to obtain the photothermal filler.

[0068] The volume fraction of the ethanol solution is 70%, and the dosage ratio of thiourea, dimethylacetamide, precursor 2 and ethanol solution is 0.045 g:8 mL:0.05 g:18 mL; the mass concentration of Tris-HCl buffer is 1.6 g / L, pH=8.5, the molar concentration of dopamine hydrochloride solution is 0.05 mol / L, and the dosage ratio of precursor 3, Tris-HCl buffer and dopamine hydrochloride solution is 0.048 g:12 mL:0.65 mL.

[0069] Example 3 A highly hydrophobic composite anti-icing coating comprises the following raw materials in parts by weight: 75 parts of a block polymer, 8 parts of a photothermal filler, 6 parts of hydrophobic nano-silica, 10 parts of an isocyanate curing agent, 1.2 parts of a defoaming agent, 1.4 parts of a leveling agent, and 18 parts of ethyl acetate;

[0070] The hydrophobic nano-silica is Degussa R812;

[0071] The isocyanate curing agent is Covestro N3390;

[0072] The defoamer is BYK-024;

[0073] The leveling agent is BYK-333.

[0074] A method for preparing a highly hydrophobic composite anti-icing coating comprises the following steps: mixing a block polymer, a photothermal filler, hydrophobic nano-silica, a defoamer, a leveling agent, and ethyl acetate; stirring the mixture for 25 minutes; adding an isocyanate curing agent; and continuing stirring the mixture for 5 minutes to obtain a highly hydrophobic composite anti-icing coating.

[0075] The block polymer is prepared by the following steps:

[0076] Step A1: Octamethylcyclotetrasiloxane, 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane, n-butyl lithium, and tetrahydrofuran were mixed, stirred at 140 rpm and 2°C, and reacted for 2.5 hours. Dimethylchlorosilane was then added, and the reaction was continued for 12 hours. The mixture was centrifuged, distilled under reduced pressure, washed, and dried to obtain a hydrogen-terminated fluorinated siloxane.

[0077] The ratio of octamethylcyclotetrasiloxane, 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane, n-butyl lithium, tetrahydrofuran and dimethylchlorosilane is 2.8 g:4.8 g:0.55 g:20 mL:0.9 g;

[0078] Step A2: mixing a hydrogen-terminated fluorosiloxane, allyl alcohol, a Custer catalyst, and tetrahydrofuran, reacting for 6 hours at a stirring rate of 240 rpm and a temperature of 60°C, rotary evaporation, precipitation with methanol aqueous solution, and drying to obtain a hydroxy-terminated fluorosiloxane; mixing a hydroxy-terminated fluorosiloxane, 4-dimethylaminopyridine, triethylamine, and tetrahydrofuran, stirring at a stirring rate of 240 rpm and a temperature of 5°C under nitrogen protection, stirring, and adding 2-bromo-2-methylpropionyl bromide, reacting for 40 minutes, then heating to room temperature, continuing the reaction for 10 hours, rotary evaporation, washing with water, and drying to obtain a modified siloxane;

[0079] The volume fraction of methanol-water solution is 75%, the amount ratio of hydrogen-terminated fluorosiloxane, allyl alcohol, Custer catalyst and tetrahydrofuran is 5.4g:0.1mL:0.024mL:30mL; the amount ratio of hydroxyl-terminated fluorosiloxane, 4-dimethylaminopyridine, triethylamine, tetrahydrofuran and 2-bromo-2-methylpropionyl bromide is 4.2g:0.062g:0.3mL:30mL:0.18mL;

[0080] Step A3: Methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, modified siloxane, pentamethyldiethylenetriamine, cuprous chloride, and cyclohexanone were mixed and reacted under argon protection at a stirring rate of 180 rpm and a temperature of 72° C. for 24 hours. The mixture was rotary evaporated, dissolved in tetrahydrofuran, filtered through a column, precipitated with methanol, and dried in vacuo to obtain a block polymer.

[0081] The usage ratio of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, modified silicone, pentamethyldiethylenetriamine, cuprous chloride and cyclohexanone is 5.8g:3.5g:1.4g:2.6g:0.09mL; 0.06g:30mL;

[0082] The photothermal filler is prepared by the following steps:

[0083] Step B1: Graphitic carbon nitride and ethanol were mixed and ultrasonically dispersed for 20 minutes. Ammonia solution and tetrabutyl titanate were added with stirring at a stirring rate of 140 rpm at room temperature and stirred for 40 minutes. The mixture was then hydrothermally reacted at 45°C for 22 hours. The mixture was cooled, centrifuged, washed with water, dried, and ground to obtain Precursor 1. Precursor 1 was mixed with sodium borohydride, ground in a mortar for 8 minutes, and then placed in a tube furnace under nitrogen protection at 300°C for 2 hours to obtain Precursor 2.

[0084] The mass fraction of ammonia solution is 25%, the amount ratio of graphite carbon nitride, ethanol, ammonia solution and tetrabutyl titanate is 0.24g:180mL:1.1mL:1.9mL; the amount ratio of precursor 1 and sodium borohydride is 0.2g:0.1g;

[0085] The graphite phase carbon nitride is Xianfeng Nano XFI10;

[0086] Step B2: thiourea and dimethylacetamide were mixed and ultrasonically dispersed for 20 minutes, and then the precursor 2 and the ethanol solution were added under stirring at a stirring rate of 240 rpm and a temperature of room temperature, and stirred for 60 minutes. Then, the mixture was reacted in a reactor at a temperature of 185°C for 12 hours to obtain the precursor 3. The precursor 3 was mixed with Tris-HCl buffer and ultrasonically dispersed for 20 minutes. The dopamine hydrochloride solution was added under stirring at a temperature of 15°C and reacted for 25 minutes to obtain the photothermal filler;

[0087] The volume fraction of the ethanol solution is 70%, and the dosage ratio of thiourea, dimethylacetamide, precursor 2 and ethanol solution is 0.05 g:10 mL:0.055 g:22 mL; the mass concentration of Tris-HCl buffer is 1.6 g / L, pH=8.5, the molar concentration of dopamine hydrochloride solution is 0.05 mol / L, and the dosage ratio of precursor 3, Tris-HCl buffer and dopamine hydrochloride solution is 0.052 g:14 mL:0.7 mL.

[0088] Comparative Example 1 Compared with Example 3, this comparative example is different in that the photothermal filler in the preparation process of the highly hydrophobic composite anti-icing coating of Example 3 is replaced by the precursor 3 of Example 3, and the other steps are the same.

[0089] Comparative Example 2 Compared with Example 3, this comparative example replaces the photothermal filler in Example 3 with a mixture of DuPont R105 titanium dioxide and Xianfeng Nano XFI10 graphite phase carbon nitride. Other steps are the same, and the ratio of titanium dioxide to graphite phase carbon nitride is 0.22g:0.24g.

[0090] Comparative Example 3 Compared with Example 3, this comparative example is different in that the block polymer in the preparation process of the highly hydrophobic composite anti-icing coating of Example 3 is replaced by the fluorocarbon resin of Daikin Fluorochemical, and the other steps are the same.

[0091] The highly hydrophobic composite anti-icing coatings prepared in Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2 and Comparative Example 3 were tested for impact resistance according to GB / T 1732-2020, adhesion according to GB / T 5210-2006, static water contact angle according to GB / T 23764-2009, and ice adhesion at -20°C according to HG / T 5367.5-2022. After the samples were left to stand for 14 days under ultraviolet irradiation conditions, their ice adhesion was tested again, and their performance retention rate was calculated to evaluate their weather resistance. The samples were placed on a refrigeration platform at a temperature of -20°C and an ambient humidity of 35±5%. Then, 10 μL of liquid droplets were dropped on the sample surface with a syringe. After the droplets completely turned into a solid phase, the samples were irradiated under a solar simulated light source, and the time it took for the droplets to turn from a completely frozen state to a liquid was recorded, which was recorded as the ice melting time. The photothermal deicing performance was evaluated. The test results are shown in Table 1 below. Test results table:

[0092] Table 1 Test results

[0093] Test items Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Impact resistance (cm) 61 62 62 58 56 53 Adhesion (MPa) 8.21 8.26 8.46 7.79 7.55 7.69 Static water contact angle (°) 136.1 135.0 137.4 122.8 117.5 129.2 Ice power (N) 22.12 21.84 21.02 28.51 29.80 24.18 Performance retention rate (%) 98.50 98.66 98.74 97.60 97.45 95.28 Ice melting time (s) 128.6 127.0 123.4 182.6 213.9 147.38

[0094] It can be seen from the test results in the table shown that Example 1, Example 2 and Example 3 are compared with Comparative Example 1, Comparative Example 2 and Comparative Example 3. Comparative Example 1 replaces the photothermal filler in the preparation process of the highly hydrophobic composite anti-icing coating of Example 3 with Precursor 3 of Example 3. Due to the lack of dopamine encapsulation, it is unable to react with the isocyanate curing agent, which leads to a decline in its performance. Comparative Example 2 replaces the photothermal filler in Example 3 with a mixture of titanium dioxide and graphite phase carbon nitride. Due to the poor photothermal efficiency of the simple mixing, its performance is declined. Comparative Example 3 replaces the block polymer in the preparation process of the highly hydrophobic composite anti-icing coating of Example 3 with Daikin Fluorochemical fluorocarbon resin. Due to the lack of block polymer, its performance is declined.

[0095] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0096] The above contents are merely examples and explanations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the concept of the invention, they should all fall within the scope of protection of the present invention.

Claims

1. A highly hydrophobic composite anti-icing coating, characterized by: The method comprises the following raw materials in parts by weight: 65-75 parts of block polymer, 5-8 parts of photothermal filler, 4-6 parts of hydrophobic nano-silica, 8-10 parts of isocyanate curing agent, 0.5-1.2 parts of defoaming agent, 0.8-1.4 parts of leveling agent and 15-18 parts of ethyl acetate; The method for preparing the highly hydrophobic composite anti-icing coating comprises the following steps: mixing a block polymer, a photothermal filler, hydrophobic nano-silica, a defoamer, a leveling agent, and ethyl acetate, stirring for 20-25 minutes, adding an isocyanate curing agent, and continuing to stir for 3-5 minutes to prepare a highly hydrophobic composite anti-icing coating; The block polymer is prepared by the following steps: Step A1: octamethylcyclotetrasiloxane, 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane, n-butyl lithium, and tetrahydrofuran are mixed, stirred at a rate of 120-140 rpm and a temperature of 0-2° C., reacted for 2-2.5 hours, then dimethylchlorosilane is added, the reaction is continued for 12 hours, centrifuged, distilled under reduced pressure, washed, and dried to obtain a hydrogen-terminated fluorinated siloxane; Step A2: Mixing a hydrogen-terminated fluorosiloxane, allyl alcohol, a Custer catalyst, and tetrahydrofuran, reacting for 4-6 hours at a stirring rate of 180-240 rpm and a temperature of 60° C., rotary evaporation, precipitation with methanol aqueous solution, and drying to obtain a hydroxy-terminated fluorosiloxane. Mixing a hydroxy-terminated fluorosiloxane, 4-dimethylaminopyridine, triethylamine, and tetrahydrofuran, stirring at a stirring rate of 180-240 rpm and a temperature of 0-5° C., stirring, and adding 2-bromo-2-methylpropionyl bromide, reacting for 30-40 minutes, then heating to room temperature, continuing the reaction for 8-10 hours, rotary evaporation, washing with water, and drying to obtain a modified siloxane; Step A3: Methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, modified siloxane, pentamethyldiethylenetriamine, cuprous chloride, and cyclohexanone were mixed, and the mixture was reacted under argon protection at a stirring rate of 140-180 rpm and a temperature of 70-72° C. for 20-24 hours. The mixture was rotary evaporated, dissolved in tetrahydrofuran, filtered through a column, precipitated with methanol, and dried in vacuo to obtain a block polymer. The photothermal filler is prepared by the following steps: Step B1: Graphite phase carbon nitride and ethanol are mixed and ultrasonically dispersed for 15-20 minutes. At a stirring rate of 120-140 rpm and room temperature, an ammonia solution and tetrabutyl titanate are added and stirred for 30-40 minutes. The mixture is then hydrothermally reacted at a temperature of 42-45°C for 20-22 hours. The mixture is cooled, centrifuged, washed with water, dried, and ground to obtain Precursor 1. Precursor 1 is mixed with sodium borohydride, ground in a mortar for 5-8 minutes, and then placed in a tube furnace under nitrogen protection at 300°C for 2 hours to obtain Precursor 2. Step B2: Mix thiourea and dimethylacetamide and ultrasonically disperse them for 15-20 minutes, then stir and add precursor 2 and ethanol solution at a stirring rate of 180-240 rpm and room temperature, stir for 40-60 minutes, and then react in a reactor at a temperature of 180-185°C for 10-12 hours to obtain precursor 3, mix precursor 3 and Tris-HCl buffer and ultrasonically disperse them for 15-20 minutes, stir and add dopamine hydrochloride solution at a temperature of 10-15°C, and react for 20-25 minutes to obtain a photothermal filler.

2. The highly hydrophobic composite anti-icing coating according to claim 1, characterized in that: In step A1, the ratio of octamethylcyclotetrasiloxane, 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane, n-butyllithium, tetrahydrofuran and dimethylchlorosilane is 2.7-2.8 g: 4.5-4.8 g: 0.52-0.55 g: 15-20 mL: 0.85-0.9 g.

3. The highly hydrophobic composite anti-icing coating according to claim 1, characterized in that: In step A2, the volume fraction of the methanol aqueous solution is 75%, the amount ratio of hydrogen-terminated fluorosilicone, allyl alcohol, Custer catalyst and tetrahydrofuran is 5.2-5.4 g: 0.08-0.1 mL: 0.02-0.024 mL: 25-30 mL; the amount ratio of hydroxyl-terminated fluorosilicone, 4-dimethylaminopyridine, triethylamine, tetrahydrofuran and 2-bromo-2-methylpropionyl bromide is 3.8-4.2 g: 0.06-0.062 g: 0.28-0.3 mL: 25-30 mL: 0.15-0.18 mL.

4. The highly hydrophobic composite anti-icing coating according to claim 1, characterized in that: In step A3, the ratio of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, modified silicone, pentamethyldiethylenetriamine, cuprous chloride and cyclohexanone is 5.6-5.8 g: 3.2-3.5 g: 1.2-1.4 g: 2.4-2.6 g: 0.08-0.09 mL: 0.05-0.06 g: 25-30 mL.

5. The highly hydrophobic composite anti-icing coating according to claim 1, characterized in that: In step B1: the mass fraction of the ammonia solution is 25%, the amount ratio of graphite phase carbon nitride, ethanol, ammonia solution and tetrabutyl titanate is 0.2-0.24g:160-180mL:0.95-1.1mL:1.8-1.9mL; the amount ratio of precursor 1 and sodium borohydride is 0.18-0.2g:0.09-0.1g.

6. The highly hydrophobic composite anti-icing coating according to claim 1, characterized in that: In step B2: the volume fraction of the ethanol solution is 70%, the amount ratio of thiourea, dimethylacetamide, precursor 2 and ethanol solution is 0.045-0.05 g: 8-10 mL: 0.05-0.055 g: 18-22 mL; the mass concentration of Tris-HCl buffer is 1.6 g / L, pH = 8.5, the molar concentration of dopamine hydrochloride solution is 0.05 mol / L, and the amount ratio of precursor 3, Tris-HCl buffer and dopamine hydrochloride solution is 0.048-0.052 g: 12-14 mL: 0.65-0.7 mL.