Composite anti-icing coating with high hydrophobicity

Abstract

The invention relates to the field of anti-icing coatings, in particular to a high-hydrophobicity composite anti-icing coating, which is prepared from the following raw materials in parts by weight: 65 to 75 parts of block polymer, 5 to 8 parts of photo-thermal filler, 4 to 6 parts of hydrophobic nano silicon dioxide, 8 to 10 parts of isocyanate curing agent, 0.5 to 1.2 parts of defoaming agent, 0.8 to 1.4 parts of flatting agent and 15 to 18 parts of ethyl acetate. A block polymer with a fluorosilicone chain segment is prepared through an atom transfer radical polymerization method, the block polymer serves as matrix resin, meanwhile, the photo-thermal filler wrapped by polydopamine is added, and therefore the problems that an anti-icing coating is poor in weather resistance, and the compatibility of the photo-thermal filler and the matrix resin is poor are solved, and the anti-icing coating has a good photo-thermal effect and is suitable for being used as an anti-icing coating. Therefore, a good anti-icing effect is achieved.

Description

Technical Field

[0001] The present invention relates to the field of anti-icing coatings, and particularly to a composite anti-icing coating with high hydrophobicity. Background Art

[0002] In high-cold and high-humidity climates, liquids are likely to condense and freeze on the surface of wire transmission towers and accumulate. Severe icing can cause wire towers to break and collapse. Currently, traditional anti-icing technologies, such as electrothermal de-icing and spraying chemical de-icing agents, 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 effectiveness and low energy consumption advantages. Currently, commonly used anti-icing coatings, such as fluorocarbon resins, although they have strong hydrophobicity, have poor mechanical durability and are prone to microstructural collapse under low-temperature impact or ultraviolet irradiation, resulting in a decline in their hydrophobic performance and thus a short service life. At the same time, in order to improve the performance of anti-icing coatings, fillers with photothermal effects are usually selected to be added to the matrix. However, due to the generally poor compatibility between photothermal fillers and matrix resins, it is extremely easy to cause further decline in the denseness and weather resistance of the coating, thereby affecting its anti-icing effect and being unable to meet market demands. Summary of the Invention

[0003] The purpose of the present invention is to provide a composite anti-icing coating with high hydrophobicity. By using atom transfer radical polymerization method to prepare a block polymer with fluorosilane segments and using it as the matrix resin, and at the same time adding a photothermal filler wrapped with polydopamine, the problems of poor weather resistance of anti-icing coatings and poor compatibility between photothermal fillers and matrix resins are solved, and it has a good photothermal effect, thus achieving a better anti-icing effect.

[0004] The purpose of the present invention can be achieved through the following technical solutions: A composite anti-icing coating with high hydrophobicity, 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 defoaming agent is BYK-024;

[0008] The leveling agent is BYK-333.

[0009] A preparation method of a highly hydrophobic composite anti-icing coating, which comprises the following steps: Mix a block polymer, a photothermal filler, hydrophobic nano-silica, an antifoaming agent, a leveling agent and ethyl acetate, stir for 20-25 min, then add an isocyanate curing agent, and continue to stir for 3-5 min to obtain a highly hydrophobic composite anti-icing coating.

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

[0011] Step A1: Mix octamethylcyclotetrasiloxane, 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane, n-butyllithium and tetrahydrofuran, react for 2-2.5 h under the conditions of a stirring rate of 120-140 rpm and a temperature of 0-2 °C, then add dimethylchlorosilane, continue to react for 12 h, centrifuge, distill under reduced pressure, wash, and dry to obtain a fluorinated silicon oxygen alkane with terminal hydrogen;

[0012] The dosage 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;

[0013] During the reaction process, using n-butyllithium as a catalyst, in tetrahydrofuran, octamethylcyclotetrasiloxane and 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane first undergo ring-opening polymerization, and then dimethylchlorosilane is added for end-capping to obtain a fluorinated silicon oxygen alkane with terminal hydrogen;

[0014] Step A2: Mix the fluorinated silicon oxygen alkane with terminal hydrogen, allyl alcohol, a Karstedt catalyst and tetrahydrofuran, react for 4-6 h under the conditions of a stirring rate of 180-240 rpm and a temperature of 60 °C, carry out rotary evaporation, precipitate with an aqueous methanol solution, and dry to obtain a fluorinated silicon oxygen alkane with terminal hydroxyl groups. Mix the fluorinated silicon oxygen alkane with terminal hydroxyl groups, 4-dimethylaminopyridine, triethylamine and tetrahydrofuran, under nitrogen protection, at a stirring rate of 180-240 rpm and a temperature of 0-5 °C, stir and add 2-bromo-2-methylpropionyl bromide, react for 30-40 min, then raise the temperature to room temperature, continue to react for 8-10 h, carry out rotary evaporation, wash with water, and dry to obtain a modified silicone;

[0015] The volume fraction of the methanol aqueous solution is 75%, and the dosage ratio of the fluorine-containing siloxane with terminal hydrogen, allyl alcohol, Karstedt's catalyst and tetrahydrofuran is 5.2 - 5.4 g : 0.08 - 0.1 mL : 0.02 - 0.024 mL : 25 - 30 mL; the dosage ratio of the fluorine-containing siloxane with terminal hydroxyl, 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 process, under the action of Karstedt's catalyst, the terminal hydrogen in the fluorine-containing siloxane with terminal hydrogen reacts with the double bond in allyl alcohol through a hydrosilylation reaction to obtain the fluorine-containing siloxane with terminal hydroxyl. Then, under the conditions of 4-dimethylaminopyridine and triethylamine, the hydroxyl group in the fluorine-containing siloxane with terminal hydroxyl reacts with 2-bromo-2-methylpropionyl bromide to obtain the modified siloxane;

[0017] Step A3: Mix methyl methacrylate, butyl acrylate, 2-hydroxyethyl methacrylate, modified siloxane, pentamethyldiethylenetriamine, copper chloride and cyclohexanone, and react for 20 - 24 h under the protection of argon, with a stirring rate of 140 - 180 rpm and a temperature of 70 - 72 °C. Then perform rotary evaporation, dissolve in tetrahydrofuran, pass through a column, precipitate with methanol, and dry under vacuum to obtain the block copolymer;

[0018] The dosage ratio of methyl methacrylate, butyl acrylate, 2-hydroxyethyl methacrylate, modified siloxane, pentamethyldiethylenetriamine, copper 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, using the modified siloxane containing the 2-bromo-2-methylpropionyl bromide structure as a macroinitiator, under the action of pentamethyldiethylenetriamine and copper chloride, through the atom transfer radical polymerization method, it reacts with the double bonds in methyl methacrylate, butyl acrylate and 2-hydroxyethyl methacrylate to obtain the block copolymer.

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

[0021] Step B1: Mix graphitic carbon nitride and ethanol and ultrasonically disperse for 15 - 20 min. Stir and add ammonia water solution and tetrabutyl titanate at a stirring rate of 120 - 140 rpm at room temperature, stir for 30 - 40 min, and then perform a hydrothermal reaction at a temperature of 42 - 45 °C for 20 - 22 h. Cool, centrifuge, wash with water, dry, and grind to obtain precursor 1. Mix precursor 1 and sodium borohydride, grind in a mortar for 5 - 8 min, and then place it in a tubular furnace. Under the protection of nitrogen and at a temperature of 300 °C, keep it warm for 2 h to obtain precursor 2;

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

[0023] The graphitic carbon nitride is Xianfeng Nano XFI10;

[0024] During the reaction process, through the low-temperature hydrothermal method, titanium dioxide particles are generated in the graphitic carbon nitride lamellae, and at the same time, a heterojunction is formed with the graphitic carbon nitride, thereby obtaining precursor 1. Then, under the action of sodium borohydride, titanium dioxide in precursor 1 is reduced, thereby forming oxygen vacancies and defect sites, and obtaining precursor 2;

[0025] Step B2: Mix thiourea and dimethylacetamide and ultrasonically disperse for 15 - 20 min. Then, under the conditions of a stirring rate of 180 - 240 rpm and room temperature, stir and add precursor 2 and ethanol solution, and stir for 40 - 60 min. Then, in a reaction kettle, under the conditions of a temperature of 180 - 185 °C, react for 10 - 12 h to obtain precursor 3. Mix precursor 3 and Tris-HCl buffer solution and ultrasonically disperse for 15 - 20 min. Under the conditions of a temperature of 10 - 15 °C, stir and add dopamine hydrochloride solution, and react for 20 - 25 min to obtain the 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 the Tris-HCl buffer solution is 1.6 g / L and pH = 8.5, the molar concentration of the dopamine hydrochloride solution is 0.05 mol / L, and the dosage ratio of precursor 3, Tris-HCl buffer solution and dopamine hydrochloride solution is 0.048 - 0.052 g : 12 - 14 mL : 0.65 - 0.7 mL;

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

[0028] Advantages of the present invention: The present invention discloses a highly hydrophobic composite anti-icing coating. By using atom transfer radical polymerization method, a block polymer with fluorosilane segments is prepared and used as the matrix resin. At the same time, a photothermal filler wrapped with polydopamine is added, thus solving the problems of poor weather resistance of the anti-icing coating and poor compatibility between the photothermal filler and the matrix resin. And it has good photothermal effect, thus achieving a better anti-icing effect;

[0029] Since the block polymer is obtained by the reaction of methyl methacrylate, butyl acrylate, 2-hydroxyethyl methacrylate and modified siloxane through atom transfer radical polymerization method, it shows a certain gradient distribution, thus making the anti-icing coating exhibit more excellent hydrophobic and weather resistance. And due to the introduction of the photothermal filler, because its surface is a polydopamine coating layer, the photothermal filler can react with the isocyanate curing agent, thus avoiding the problem of poor compatibility between the photothermal filler and the matrix resin, and further improving the mechanical properties of the anti-icing coating. And because the photothermal filler itself is based on graphitic carbon nitride as the matrix, and titanium dioxide is generated on the surface by low-temperature hydrothermal method, and then obtained after reduction and doping, its multi-step modification effectively improves the photothermal conversion efficiency of the photothermal filler, thus further improving the anti-icing performance of the coating, and also reducing the damage of ultraviolet irradiation to the performance of the coating to a certain extent, and improving the weather resistance of the coating. Specific embodiments

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0031] Example 1 A highly hydrophobic composite anti-icing coating, which comprises the following raw materials in parts by weight: 65 parts of block polymer, 5 parts of photothermal filler, 4 parts of hydrophobic nano-silica, 8 parts of isocyanate curing agent, 1.2 parts of defoaming agent, 0.8 part of 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 defoaming agent is BYK-024;

[0035] The leveling agent is BYK-333.

[0036] A preparation method of a highly hydrophobic composite anti-icing coating, which comprises the following steps: Mix a block polymer, a photothermal filler, hydrophobic nano-silica, an antifoaming agent, a leveling agent and ethyl acetate, stir for 20 min, then add an isocyanate curing agent, and continue to stir for 5 min to obtain a highly hydrophobic composite anti-icing coating.

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

[0038] Step A1: Mix octamethylcyclotetrasiloxane, 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane, n-butyllithium and tetrahydrofuran, react at a stirring rate of 120 rpm and a temperature of 0 °C for 2 h, then add dimethylchlorosilane, continue to react for 12 h, centrifuge, distill under reduced pressure, wash, and dry to obtain a fluorosiloxane with terminal hydrogen;

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

[0040] Step A2: Mix the fluorosiloxane with terminal hydrogen, allyl alcohol, a Karstedt catalyst and tetrahydrofuran, react at a stirring rate of 180 rpm and a temperature of 60 °C for 4 h, perform rotary evaporation, precipitate with an aqueous methanol solution, and dry to obtain a fluorosiloxane with terminal hydroxyl groups. Mix the fluorosiloxane with terminal hydroxyl groups, 4-dimethylaminopyridine, triethylamine and tetrahydrofuran, stir and add 2-bromo-2-methylpropionyl bromide under nitrogen protection at a stirring rate of 180 rpm and a temperature of 0 °C, react for 30 min, then raise the temperature to room temperature and continue to react for 8 h, perform rotary evaporation, wash with water, and dry to obtain a modified siloxane;

[0041] The volume fraction of the aqueous methanol solution is 75%. The dosage ratio of the fluorosiloxane with terminal hydrogen, allyl alcohol, a Karstedt catalyst and tetrahydrofuran is 5.2 g: 0.08 mL: 0.02 mL: 25 mL; The dosage ratio of the fluorosiloxane with terminal hydroxyl groups, 4-dimethylaminopyridine, triethylamine, tetrahydrofuran and 2-bromo-2-methylpropionyl bromide is 3.8 g: 0.06 g: 0.28 mL: 25 mL: 0.15 mL;

[0042] Step A3: Mix methyl methacrylate, butyl acrylate, 2-hydroxyethyl methacrylate, the modified siloxane, pentamethyldiethylenetriamine, copper chloride and cyclohexanone, react under argon protection at a stirring rate of 140 rpm and a temperature of 70 °C for 20 h, perform rotary evaporation, dissolve in tetrahydrofuran, pass through a column, precipitate with methanol, and dry under vacuum to obtain a block polymer;

[0043] The dosage ratio of methyl methacrylate, butyl acrylate, 2-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: Mix graphitic carbon nitride and ethanol and ultrasonically disperse for 20 min. Under the conditions of a stirring rate of 120 rpm and room temperature, stir and add ammonia water solution and tetrabutyl titanate, stir for 40 min, and then carry out a hydrothermal reaction at 42 °C for 22 h. Cool, centrifuge, wash with water, dry, and grind to obtain precursor 1. Mix precursor 1 and sodium borohydride, grind in a mortar for 5 min, and then place it in a tube furnace. Under nitrogen protection and at a temperature of 300 °C, keep warm for 2 h to obtain precursor 2;

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

[0047] The graphitic carbon nitride is Xianfeng Nano XFI10;

[0048] Step B2: Mix thiourea and dimethylacetamide and ultrasonically disperse for 20 min. Then, under the conditions of a stirring rate of 180 rpm and room temperature, stir and add precursor 2 and ethanol solution, stir for 60 min, and then carry out a reaction in a reaction kettle at 180 °C for 12 h to obtain precursor 3. Mix precursor 3 and Tris-HCl buffer solution and ultrasonically disperse for 15 min. Under the condition of a temperature of 10 °C, stir and add hydrochloric acid dopamine solution, and react for 25 min to obtain the photothermal filler;

[0049] 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: 8 mL: 0.05 g: 18 mL; the mass concentration of the Tris-HCl buffer solution is 1.6 g / L, pH = 8.5, the molar concentration of the hydrochloric acid dopamine solution is 0.05 mol / L, and the dosage ratio of precursor 3, Tris-HCl buffer solution and hydrochloric acid dopamine solution is 0.052 g: 12 mL: 0.7 mL.

[0050] Example 2 A highly hydrophobic composite anti-icing coating, which comprises the following raw materials in parts by weight: 65 parts of block polymer, 8 parts of photothermal filler, 6 parts of hydrophobic nano-silica, 10 parts of isocyanate curing agent, 0.5 defoamer, 0.8 part of 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 defoaming agent is BYK-024 from BYK;

[0054] The leveling agent is BYK-333 from BYK.

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

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

[0057] Step A1: Mix octamethylcyclotetrasiloxane, 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane, n-butyllithium and tetrahydrofuran, react at a stirring rate of 140 rpm and a temperature of 2 °C for 2 h, then add dimethylchlorosilane, continue to react for 12 h, centrifuge, distill under reduced pressure, wash, and dry to obtain a fluorosiloxane with terminal hydrogen;

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

[0059] Step A2: Mix the fluorosiloxane with terminal hydrogen, allyl alcohol, Karstedt catalyst and tetrahydrofuran, react at a stirring rate of 240 rpm and a temperature of 60 °C for 4 h, rotary evaporate, precipitate with methanol aqueous solution, and dry to obtain a fluorosiloxane with terminal hydroxyl. Mix the fluorosiloxane with terminal hydroxyl, 4-dimethylaminopyridine, triethylamine and tetrahydrofuran, stir and add 2-bromo-2-methylpropionyl bromide under nitrogen protection at a stirring rate of 180 rpm and a temperature of 5 °C, react for 30 min, then raise the temperature to room temperature, continue to react for 10 h, rotary evaporate, wash with water, and dry to obtain a modified siloxane;

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

[0061] Step A3: Mix methyl methacrylate, butyl acrylate, 2-hydroxyethyl methacrylate, modified siloxane, pentamethyldiethylenetriamine, cuprous chloride and cyclohexanone. Under the protection of argon, with a stirring rate of 180 rpm and a temperature of 70 °C, react for 24 h, perform rotary evaporation, dissolve in tetrahydrofuran, pass through a column, precipitate with methanol, and dry under vacuum to obtain a block polymer;

[0062] The dosage ratio of methyl methacrylate, butyl acrylate, 2-hydroxyethyl methacrylate, modified siloxane, 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 through the following steps:

[0064] Step B1: Mix graphitic carbon nitride and ethanol and ultrasonically disperse for 15 min. Under a stirring rate of 120 rpm and at room temperature, stir and add ammonia water solution and tetrabutyl titanate, stir for 30 min, and then under a temperature of 42 °C, perform a hydrothermal reaction for 20 h, cool, centrifuge, wash with water, dry, and grind to obtain precursor 1. Mix precursor 1 and sodium borohydride, grind in a mortar for 5 min, and then place it in a tube furnace. Under the protection of nitrogen and at a temperature of 300 °C, keep warm for 2 h to obtain precursor 2;

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

[0066] The graphitic carbon nitride is Xianfeng Nano XFI10;

[0067] Step B2: Mix thiourea and dimethylacetamide and ultrasonically disperse for 15 min. Then under a stirring rate of 180 rpm and at room temperature, stir and add precursor 2 and ethanol solution, stir for 40 min, and then in a reaction kettle, under a temperature of 180 °C, react for 10 h to obtain precursor 3. Mix precursor 3 and Tris-HCl buffer solution and ultrasonically disperse for 15 min. Under a temperature of 10 °C, stir and add hydrochloric acid dopamine solution, and react for 20 min 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 the ethanol solution is 0.045 g: 8 mL: 0.05 g: 18 mL; the mass concentration of the Tris-HCl buffer solution is 1.6 g / L, pH = 8.5, the molar concentration of the dopamine hydrochloride solution is 0.05 mol / L, and the dosage ratio of precursor 3, the Tris-HCl buffer solution and the dopamine hydrochloride solution is 0.048 g: 12 mL: 0.65 mL.

[0069] Example 3 A highly hydrophobic composite anti-icing coating, which 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 an antifoaming 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 antifoaming agent is BYK-024 of BYK;

[0073] The leveling agent is BYK-333 of BYK.

[0074] A preparation method of a highly hydrophobic composite anti-icing coating, which comprises the following steps: mixing the block polymer, the photothermal filler, the hydrophobic nano-silica, the antifoaming agent, the leveling agent and the ethyl acetate, stirring for 25 min, then adding the isocyanate curing agent, and continuing to stir for 5 min to obtain a highly hydrophobic composite anti-icing coating.

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

[0076] Step A1: Mix octamethylcyclotetrasiloxane, 1,3,5-tris(3,3,3-trifluoropropyl)-1,3,5-trimethylcyclotrisiloxane, n-butyllithium and tetrahydrofuran, react at a stirring rate of 140 rpm and a temperature of 2 °C for 2.5 h, then add dimethylchlorosilane, continue to react for 12 h, centrifuge, distill under reduced pressure, wash, and dry to obtain a fluorine-containing siloxane with terminal hydrogen;

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

[0078] Step A2: Mix the terminal hydrogen-containing fluorosiloxane, allyl alcohol, Karstedt's catalyst, and tetrahydrofuran. React for 6 h under the conditions of a stirring rate of 240 rpm and a temperature of 60 °C. Carry out rotary evaporation, precipitate with an aqueous methanol solution, and dry to obtain the terminal hydroxyl-containing fluorosiloxane. Mix the terminal hydroxyl-containing fluorosiloxane, 4-dimethylaminopyridine, triethylamine, and tetrahydrofuran. Under nitrogen protection, with a stirring rate of 240 rpm and a temperature of 5 °C, stir and add 2-bromo-2-methylpropionyl bromide. React for 40 min, then raise the temperature to room temperature and continue to react for 10 h. Carry out rotary evaporation, wash with water, and dry to obtain the modified siloxane;

[0079] The volume fraction of the aqueous methanol solution is 75%. The dosage ratio of the terminal hydrogen-containing fluorosiloxane, allyl alcohol, Karstedt's catalyst, and tetrahydrofuran is 5.4 g: 0.1 mL: 0.024 mL: 30 mL; The dosage ratio of the terminal hydroxyl-containing fluorosiloxane, 4-dimethylaminopyridine, triethylamine, tetrahydrofuran, and 2-bromo-2-methylpropionyl bromide is 4.2 g: 0.062 g: 0.3 mL: 30 mL: 0.18 mL;

[0080] Step A3: Mix methyl methacrylate, butyl acrylate, 2-hydroxyethyl methacrylate, the modified siloxane, pentamethyldiethylenetriamine, copper chloride, and cyclohexanone. React for 24 h under the conditions of argon protection, a stirring rate of 180 rpm, and a temperature of 72 °C. Carry out rotary evaporation, dissolve in tetrahydrofuran, pass through a column, precipitate with methanol, and dry under vacuum to obtain the block polymer;

[0081] The dosage ratio of methyl methacrylate, butyl acrylate, 2-hydroxyethyl methacrylate, the modified siloxane, pentamethyldiethylenetriamine, copper chloride, and cyclohexanone is 5.8 g: 3.5 g: 1.4 g: 2.6 g: 0.09 mL; 0.06 g: 30 mL;

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

[0083] Step B1: Mix graphitic carbon nitride and ethanol and ultrasonically disperse for 20 min. Under the conditions of a stirring rate of 140 rpm and room temperature, stir and add an aqueous ammonia solution and tetrabutyl titanate, and stir for 40 min. Then, under the condition of a temperature of 45 °C, carry out a hydrothermal reaction for 22 h. Cool, centrifuge, wash with water, dry, and grind to obtain the precursor 1. Mix the precursor 1 and sodium borohydride, grind in a mortar for 8 min, and then place it in a tubular furnace. Under nitrogen protection and at a temperature of 300 °C, keep warm for 2 h to obtain the precursor 2;

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

[0085] The graphitic carbon nitride is Xianfeng Nano XFI10;

[0086] Step B2: Mix thiourea and dimethylacetamide and ultrasonically disperse them for 20 min. Then, under the conditions of a stirring rate of 240 rpm and room temperature, stir and add precursor 2 and an ethanol solution, and stir for 60 min. Then, in a reaction kettle, react at 185°C for 12 h to obtain precursor 3. Mix precursor 3 and a Tris-HCl buffer solution and ultrasonically disperse them for 20 min. Under the condition of a temperature of 15°C, stir and add a dopamine hydrochloride solution, and react for 25 min to obtain a photothermal filler;

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

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

[0089] Comparative Example 2 Compared with Example 3, in this comparative example, the photothermal filler in Example 3 was replaced with a mixture of DuPont R105 titanium dioxide and Xianfeng Nano XFI10 graphitic carbon nitride, and other steps were the same. The dosage ratio of titanium dioxide and graphitic carbon nitride is 0.22 g: 0.24 g.

[0090] Comparative Example 3 Compared with Example 3, in this comparative example, the block polymer in the preparation process of the highly hydrophobic composite anti-icing coating in Example 3 was replaced with Daikin fluorochemical fluorocarbon resin, and other steps were the same.

[0091] Take 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. Refer to GB / T 1732-2020 for testing impact resistance, refer to GB / T 5210-2006 for testing adhesion, refer to GB / T 23764-2009 for testing static water contact angle, refer to HG / T 5367.5-2022 for testing ice adhesion force at -20°C. After leaving the sample standing for 14 days under ultraviolet irradiation conditions, then test its ice adhesion force and calculate its performance retention rate to evaluate its weather resistance. Place the sample on a refrigeration platform with a temperature of -20°C and an environmental humidity of 35±5%. Then use a syringe to drop 10 μL of liquid droplets on the surface of the sample. Wait until the liquid droplets completely turn into a solid phase, and then irradiate the sample under a simulated solar light source. Record the time when the liquid droplets change from a completely frozen state to a liquid state, denoted as the ice melting time, to evaluate its photothermal de-icing performance. The test results are shown in Table 1 below:

[0092] Table 1 Test Results

[0093]

[0094] It can be seen from the test results in the table that when comparing Example 1, Example 2, and Example 3 with Comparative Example 1, Comparative Example 2, and Comparative Example 3, in Comparative Example 1, the photothermal filler in the preparation process of the highly hydrophobic composite anti-icing coating in Example 3 was replaced with the precursor 3 of Example 3. Due to the lack of dopamine coating, it could not react with the isocyanate curing agent, resulting in a decline in its performance. In Comparative Example 2, the photothermal filler in Example 3 was replaced with a mixture of titanium dioxide and graphitic carbon nitride. Due to the poor photothermal efficiency of simple mixing, its performance declined. In Comparative Example 3, the block polymer in the preparation process of the highly hydrophobic composite anti-icing coating in Example 3 was replaced with Daikin fluorochemical fluorocarbon resin. Due to the lack of block polymer, its performance declined.

[0095] In the description of the specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0096] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of this technology can make various modifications, supplements, or use similar methods to replace the specific embodiments described, as long as they do not deviate from the concept of the invention, they should fall within the protection scope of the present invention.

Claims

1. A highly hydrophobic composite anti-icing coating, characterized in that: 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; 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.

2. The highly hydrophobic composite anti-icing coating according to claim 1, characterized in that: 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, and reacted for 2-2.5 hours at a stirring rate of 120-140 rpm and a temperature of 0-2° C., and then dimethylchlorosilane is added, and the reaction is continued for 12 hours, centrifuged, distilled under reduced pressure, washed, and dried to obtain a terminal hydrogen-containing fluorinated siloxane; Step A2: mixing terminal hydrogen-containing fluorinated siloxane, allyl alcohol, 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 terminal hydroxyl-containing fluorinated siloxane; mixing terminal hydroxyl-containing fluorinated siloxane, 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 modified siloxane; Step A3: Methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, modified siloxane, pentamethyldiethylenetriamine, cuprous chloride and cyclohexanone are mixed, and the mixture is reacted for 20-24 hours under argon protection, at a stirring rate of 140-180 rpm and a temperature of 70-72° C., and then rotary evaporated, dissolved in tetrahydrofuran, passed through a column, precipitated with methanol, and dried in vacuo to obtain a block polymer.

3. The highly hydrophobic composite anti-icing coating according to claim 2, characterized in that: In step A1: the usage 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.

4. The highly hydrophobic composite anti-icing coating according to claim 2, characterized in that: In step A2, the volume fraction of the methanol aqueous solution is 75%, the amount ratio of the terminal hydrogen-containing fluorinated siloxane, 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 the terminal hydroxyl-containing fluorinated siloxane, 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.

5. The highly hydrophobic composite anti-icing coating according to claim 2, characterized in that: In step A3, the usage ratio of methyl methacrylate, butyl acrylate, hydroxyethyl methacrylate, modified siloxane, 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.

6. The highly hydrophobic composite anti-icing coating according to claim 1, characterized in that: The photothermal filler is prepared by the following steps: Step B1: Mix graphite phase carbon nitride and ethanol and ultrasonically disperse for 15-20 minutes, stir and add ammonia solution and tetrabutyl titanate at a stirring rate of 120-140 rpm and room temperature, stir for 30-40 minutes, then hydrothermally react at a temperature of 42-45°C for 20-22 hours, cool, centrifuge, wash, dry, grind to obtain precursor 1, mix precursor 1 and sodium borohydride, grind in a mortar for 5-8 minutes, then place in a tubular furnace, and keep warm at 300°C for 2 hours under nitrogen protection 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 180-240rpm 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.

7. The highly hydrophobic composite anti-icing coating according to claim 6, characterized in that: In step B1: 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.

8. The highly hydrophobic composite anti-icing coating according to claim 6, 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 0.045-0.05g:8-10mL:0.05-0.055g:18-22mL; the mass concentration of Tris-HCl buffer is 1.6g / L, pH=8.5, the molar concentration of dopamine hydrochloride solution is 0.05mol / L, and the amount ratio of precursor 3, Tris-HCl buffer and dopamine hydrochloride solution is 0.048-0.052g:12-14mL:0.65-0.7mL.

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