Ultraviolet resistant antioxidant multilayer composite drag reduction film and preparation method thereof

Abstract

The present application relates to the technical field of polyurethane film, in particular to a kind of UV-resistant antioxidant multilayer composite drag-reducing film and preparation method thereof.The present application obtains silicone drag-reducing coating by adding hydroxyl-terminated polydimethylsiloxane, fluorine-containing polystyrene-coated titanium dioxide material, antibacterial low-surface-energy modified titanium dioxide, tetraethyl orthosilicate and additives.Then polyurethane thermoplastic elastomer, flame retardant, stearic acid, antioxidant are mixed, and TPU base film is obtained by melt extrusion and blow molding into film;composite base film is obtained by laminating PET release film coated with adhesive and TPU base film.Silicone drag-reducing coating is coated on the surface of composite base film, and finished product is obtained after curing.The finished product prepared by the present application has excellent drag-reducing property, UV resistance and antibacterial property, so it has wide application prospect in the technical field of polyurethane film.

Description

Technical Field

[0001] This invention relates to the field of polyurethane film technology, specifically to a UV-resistant, oxidation-resistant multilayer composite drag-reducing film and its preparation method. Background Technology

[0002] As industrial technology advances towards higher efficiency and energy conservation, the application value of functional thin-film materials in energy, transportation, and medical fields is becoming increasingly prominent. Multilayer composite drag-reducing membranes, with their unique structure and properties, have demonstrated significant modern value in multiple fields. In the aerospace field, the use of multilayer composite drag-reducing membranes on aircraft surfaces can significantly reduce air friction drag during flight, improve flight efficiency, increase range, and simultaneously reduce energy consumption. This is crucial for improving the economic efficiency and sustainability of aerospace transportation. In the marine engineering field, multilayer composite drag-reducing membranes also demonstrate unique value. Using these membranes on ship surfaces can reduce water resistance during navigation, increase speed, and reduce fuel consumption. Simultaneously, the drag-reducing membranes can prevent marine organisms from adhering to the hull surface, reducing the impact of biofouling on ship performance, extending the ship's service life, and reducing maintenance costs.

[0003] However, in outdoor environments, prolonged exposure to ultraviolet light can easily trigger chemical reactions such as molecular chain breakage and oxidation of the drag-reducing membrane material, leading to aging, brittleness, and performance degradation. Therefore, it is necessary to improve the UV resistance of the membrane to extend its service life, ensuring its continuous and stable drag-reducing effect during long-term outdoor use and reducing replacement costs. Furthermore, in certain environments, bacteria can easily grow on the surface of the drag-reducing membrane. Bacterial growth not only affects the performance of the membrane but may also pose hygiene risks. Therefore, it is necessary to improve its antibacterial properties to inhibit bacterial growth and reproduction on the membrane surface, ensuring its cleanliness and hygiene, and guaranteeing its safe application in relevant fields.

[0004] To overcome the shortcomings of the prior art, the present invention provides a UV-resistant and antioxidant multilayer composite drag-reducing film and its preparation method. Summary of the Invention

[0005] The purpose of this invention is to provide a UV-resistant, antioxidant, multilayer composite drag-reducing film and its preparation method, so as to solve the problems raised in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for preparing a UV-resistant, antioxidant, multilayer composite drag-reducing film includes the following steps:

[0008] Step 1: Mix hydroxyl-terminated polydimethylsiloxane, defoamer, and leveling agent. After stirring and dispersing evenly, add fluorinated polystyrene-coated titanium dioxide material and antibacterial low surface energy modified titanium dioxide. Stir and disperse evenly to obtain a pretreated silicone coating. Then add solvent to the pretreated silicone coating and stir evenly. Add tetraethyl orthosilicate and dibutyltin dilaurate and stir evenly to obtain a silicone drag-reducing coating.

[0009] Step 2: Mix polyurethane thermoplastic elastomer, flame retardant, stearic acid, and antioxidant, and melt extrude and blow mold to form a film to obtain a TPU base film; laminate the PET release film coated with adhesive and the TPU base film together and hot press to obtain a composite base film; apply an organosilicon drag-reducing coating to the surface of the composite base film and cure at 25-30℃ for 8-10 hours to obtain the finished product.

[0010] In a more optimized manner, the content of each component in the organosilicon drag-reducing coating is as follows (by mass): 40-50 parts hydroxyl-terminated polydimethylsiloxane, 0.7-0.8 parts defoamer, 0.25-0.30 parts leveling agent, 5-7 parts fluorinated polystyrene-coated titanium dioxide material, 5-7 parts antibacterial low surface energy modified titanium dioxide, 50-60 parts solvent, 2-3 parts tetraethyl orthosilicate, and 0.45-0.50 parts dibutyltin dilaurate.

[0011] In a more optimized manner, the defoamer is specifically defoamer BYK066, the leveling agent is specifically leveling agent 3700, and the solvent is specifically a mixture of xylene, cyclohexanone, and ethanol in a mass ratio of 9:1:2.

[0012] In a more optimized manner, the content of each component of the TPU base film is as follows: by mass parts, 80-90 parts of polyurethane thermoplastic elastomer, 8-10 parts of flame retardant, 2-3 parts of stearic acid, and 3-4 parts of antioxidant; the antioxidant is specifically antioxidant 1010.

[0013] More optimally, the flame retardant is specifically magnesium hydroxide; the adhesive is specifically a polyacrylate pressure-sensitive adhesive.

[0014] Ideally, the thickness of the silicone drag-reducing coating on the surface of the composite base film is 70-90 μm.

[0015] A more optimized preparation process for fluorinated polystyrene-coated titanium dioxide materials is as follows:

[0016] Step S1: Methacryloxypropyltrimethoxysilane was added to anhydrous ethanol, stirred and dissolved, and then deionized water was added for pre-hydrolysis to obtain a silane coupling agent solution; nano-titanium dioxide was added to anhydrous ethanol, ultrasonically dispersed evenly, and then heated to 75-80℃, and then the silane coupling agent solution was slowly added dropwise, and the reaction was continuously refluxed for 6-7 hours. After the reaction was completed, the modified titanium dioxide was obtained by centrifugation, washing and drying.

[0017] Step S2: Under nitrogen atmosphere, modified titanium dioxide, anhydrous ethanol, and deionized water are mixed and ultrasonically dispersed. Then, polyvinylpyrrolidone (PVP) is added as a dispersant, and the mixture is stirred and heated to 70-75°C. Then, p-trifluoromethylstyrene and azobisisobutyronitrile (AIBN) are added, and the reaction is continued for 15-18 hours. After the reaction is completed, the mixture is centrifuged, washed, and dried to obtain fluorinated polystyrene-coated titanium dioxide material.

[0018] In a more optimized manner, in step S1, the reaction mass ratio of methacryloyloxypropyltrimethoxysilane to nano-titanium dioxide is (1.1-1.2):1; the mass-volume ratio of methacryloyloxypropyltrimethoxysilane, anhydrous ethanol, and deionized water is 1g:(3.0-3.5)mL:0.45mL; and the mass-volume ratio of nano-titanium dioxide to anhydrous ethanol is 1g:(65-70)mL.

[0019] In step S2, the content of each component of the raw material for preparing fluorinated polystyrene-coated titanium dioxide material is as follows (by mass): 1.6-1.8 parts modified titanium dioxide, 95-100 parts anhydrous ethanol, 5-7 parts deionized water, 2-3 parts dispersant polyvinylpyrrolidone, 12-14 parts p-trifluoromethylstyrene, and 0.12-0.14 parts azobisisobutyronitrile.

[0020] A more optimized preparation process for antibacterial, low surface energy modified titanium dioxide is as follows:

[0021] Step S1: Methacryloxypropyltrimethoxysilane was added to anhydrous ethanol, stirred and dissolved, and then deionized water was added for pre-hydrolysis to obtain a silane coupling agent solution; nano-titanium dioxide was added to anhydrous ethanol, ultrasonically dispersed evenly, and then heated to 75-80℃, and then the silane coupling agent solution was slowly added dropwise, and the reaction was continuously refluxed for 6-7 hours. After the reaction was completed, the modified titanium dioxide was obtained by centrifugation, washing and drying.

[0022] Step S2: Add the terminal olefin fluorination product, quaternary ammonium acrylate, and trifluoroethyl methacrylate to anhydrous ethanol, stir evenly, then add modified titanium dioxide, ultrasonically disperse for 30-40 min, then add azobisisobutyronitrile, and reflux at 75-80℃ for 6-8 h. After the reaction is completed, filter under reduced pressure, wash, and dry to obtain antibacterial low surface energy modified titanium dioxide.

[0023] In a more optimized manner, in step S1, the reaction mass ratio of methacryloyloxypropyltrimethoxysilane to nano-titanium dioxide is (1.1-1.2):1; the mass-volume ratio of methacryloyloxypropyltrimethoxysilane, anhydrous ethanol, and deionized water is 1g:(3.0-3.5)mL:0.45mL; and the mass-volume ratio of nano-titanium dioxide to anhydrous ethanol is 1g:(65-70)mL.

[0024] In step S2, the content of each component of the raw material for preparing antibacterial low surface energy modified titanium dioxide is as follows (by mass): 5-7 parts of terminal olefin fluorination product, 4-5 parts of quaternary ammonium acrylate, 3.0-3.5 parts of trifluoroethyl methacrylate, 110-130 parts of anhydrous ethanol, 6-8 parts of modified titanium dioxide, and 0.12-0.15 parts of azobisisobutyronitrile.

[0025] A more optimized preparation process for the fluorinated terminal olefin product is as follows: Hexafluorobutanol is slowly heated to 75-80℃, then isophorone diisocyanate is added dropwise. After the addition is complete, dibutyltin dilaurate is added, and the reaction is continued for 3-4 hours. After the reaction is complete, the product is washed and dried to obtain the fluorinated terminal olefin product. Eugenol is added to tetrahydrofuran under nitrogen atmosphere, stirred evenly, and then the fluorinated terminal olefin product and dibutyltin dilaurate are added. The mixture is stirred and reacted at 60-65℃ for 3-5 hours. After the reaction is complete, the product is rotary evaporated, washed, and dried to obtain the fluorinated terminal olefin product.

[0026] In a more optimized manner, when preparing the terminal isocyanate group product, the reaction molar ratio of hexafluorobutanol to isophorone diisocyanate is (0.9-1.0):1; when preparing the terminal olefin fluorinated product, the reaction molar ratio of the terminal isocyanate group product to eugenol is 1:(1.0-1.1).

[0027] A more optimized preparation process for quaternary ammonium acrylate is as follows: dimethylaminoethyl methacrylate is added to acetone and stirred until homogeneous to obtain an acrylic acid solution; allyl chloride is added to acetone and stirred until homogeneous to obtain an allyl chloride solution; the allyl chloride solution is added dropwise to the acrylic acid solution, and the mixture is refluxed and stirred at 50-55℃ for 7-9 hours. After the reaction is completed, the mixture is distilled under reduced pressure, washed, filtered, and dried to obtain the quaternary ammonium acrylate.

[0028] The optimal reaction mass ratio of dimethylaminoethyl methacrylate to allyl chloride is 2:(1.0-1.1).

[0029] The beneficial effects of this invention are:

[0030] The key feature of this invention is that, in step one, a fluorinated polystyrene-coated titanium dioxide material is prepared by adding modified titanium dioxide, dispersant polyvinylpyrrolidone, p-trifluoromethylstyrene, and azobisisobutyronitrile (AIBN) and undergoing a polymerization reaction. Trifluoromethylstyrene monomer is polymerized on the surface of the methacryloyloxypropyltrimethoxysilane-modified titanium dioxide material via free radical polymerization to form a fluorinated polystyrene coating layer. This coating structure allows the fluorinated groups to be uniformly distributed on the material surface, fully utilizing its low surface energy characteristics. Furthermore, this coating layer is tightly bonded to the titanium dioxide surface and can stably exist on the material surface, ensuring the durability of the low surface energy characteristics and thus continuously and effectively reducing fluid resistance. In addition, nano-titanium dioxide has excellent ultraviolet absorption capabilities; when fluorinated polystyrene is coated on the titanium dioxide surface, the titanium dioxide can still exert its ultraviolet absorption function, protecting the material from ultraviolet damage. The fluorinated polystyrene coating layer not only utilizes the ultraviolet absorption properties of titanium dioxide but also forms a protective film itself, further blocking the penetration of ultraviolet rays. Meanwhile, the stable structure formed by the polymerization reaction makes the molecular structure of the material less susceptible to damage under ultraviolet radiation, thus maintaining the stability of the material's performance and exhibiting excellent UV resistance.

[0031] In step one, the reaction mechanism of the terminal olefin fluorination product is as follows: hexafluorobutanol and isophorone diisocyanate undergo a nucleophilic addition reaction under the catalysis of dibutyltin dilaurate to obtain the terminal isocyanate product. The terminal isocyanate product is then mixed with eugenol, and a further nucleophilic addition reaction occurs, introducing a carbon-carbon double bond to obtain the terminal olefin fluorination product. The reaction mechanism of the quaternary ammonium acrylate is as follows: dimethylaminoethyl methacrylate and allyl chloride undergo a nucleophilic substitution reaction to obtain quaternary ammonium acrylate with antibacterial quaternary ammonium groups. Antibacterial low surface energy modified titanium dioxide is prepared by adding the terminal olefin fluorination product, the quaternary ammonium acrylate, trifluoroethyl methacrylate, modified titanium dioxide, and azobisisobutyronitrile (AIBN). Through the polymerization reaction initiated by AIBN, the unsaturated bonds in the terminal olefin fluorination product, the quaternary ammonium acrylate, and trifluoroethyl methacrylate are opened, reacting with the active groups on the surface of the modified titanium dioxide to form a tight coating layer. This coating structure allows fluorine-containing groups to be fully exposed on the material surface, maximizing the effect of low surface energy. Furthermore, during the polymerization reaction, the quaternary ammonium acrylate, along with other monomers, polymerizes on the modified titanium dioxide surface to form a polymer network. The quaternary ammonium salt groups are uniformly distributed within this network and exposed on the material surface. When bacteria come into contact with the material surface, the quaternary ammonium salt groups can rapidly interact with the bacteria, exerting an antibacterial effect. Moreover, the structure of the polymer network ensures the stability and durability of the quaternary ammonium salt groups, enabling the material to continuously and effectively inhibit bacterial growth during long-term use. Simultaneously, the polymer coating on the modified titanium dioxide surface allows the nano-titanium dioxide to absorb ultraviolet energy, while the polymer layer prevents further damage to the internal structure of the material from ultraviolet radiation. The combined effect of these two factors results in excellent UV resistance for the antibacterial, low-surface-energy modified titanium dioxide.

[0032] A silicone drag-reducing coating was obtained by adding hydroxyl-terminated polydimethylsiloxane, fluorinated polystyrene-coated titanium dioxide, antibacterial low surface energy modified titanium dioxide, tetraethyl orthosilicate, and additives. Tetraethyl orthosilicate undergoes hydrolysis and condensation polymerization under the catalysis of dibutyltin dilaurate, forming a siloxane network structure. The hydroxyl groups of the hydroxyl-terminated polydimethylsiloxane participate in the formation of this network structure, undergoing a condensation reaction with the silanol groups generated from the hydrolysis of tetraethyl orthosilicate, thus fixing the polydimethylsiloxane within the network. The fluorinated polystyrene-coated titanium dioxide and the antibacterial low surface energy modified titanium dioxide are also uniformly dispersed within this network structure. This stable network structure firmly fixes the low surface energy polydimethylsiloxane and fluorinated polystyrene groups to the coating surface of the composite base film, ensuring that the coating surface of the composite base film continuously maintains low surface energy characteristics, guaranteeing the stability and long-term effectiveness of the drag-reducing performance. Furthermore, the siloxane network structure effectively ensures that the coating can continuously and effectively inhibit bacterial growth during long-term use and protects the molecular chains inside the coating from being broken by ultraviolet light, thus giving the coating excellent UV resistance. Therefore, the multilayer composite drag-reducing film prepared by this invention has excellent drag reduction, UV resistance, and antibacterial properties, and thus has broad application prospects in the field of polyurethane film technology. Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Raw material source:

[0035] Nano-titanium dioxide, provided by Zhoushan Mingri Nanomaterials Co., Ltd., rutile type, particle size 50nm; polyvinylpyrrolidone, specifically K30, molecular weight 40000g / mol; hydroxyl-terminated polydimethylsiloxane, provided by Jinan Xinglongda Chemical Co., Ltd., model 209; polyurethane thermoplastic elastomer, provided by Dongguan Jinqun Plastics Co., Ltd., item number T3385; PET release film, provided by Dongguan Dongxin Composite Materials Co., Ltd., model DX-03; polyacrylate pressure-sensitive adhesive, provided by Dongguan Wanjiang Jianda Adhesive Products Co., Ltd., model 3808-1A; by weight, one part is 1g.

[0036] Example 1: Step 1: Step S1: Methacryloxypropyltrimethoxysilane was added to anhydrous ethanol, stirred and dissolved, and then deionized water was added for pre-hydrolysis to obtain a silane coupling agent solution; nano-titanium dioxide was added to anhydrous ethanol, ultrasonically dispersed evenly, and then heated to 80°C. The silane coupling agent solution was then slowly added dropwise, and the reaction was continuously refluxed for 7 hours. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain modified titanium dioxide; the reaction mass ratio of methacryloxypropyltrimethoxysilane to nano-titanium dioxide was 1.15:1; the mass-volume ratio of methacryloxypropyltrimethoxysilane, anhydrous ethanol, and deionized water was 1g:3.2mL:0.45mL; and the mass-volume ratio of nano-titanium dioxide to anhydrous ethanol was 1g:67mL.

[0037] Step S2: Under nitrogen atmosphere, 1.6g of modified titanium dioxide, 95g of anhydrous ethanol and 5g of deionized water were mixed and ultrasonically dispersed. Then, 2g of dispersant polyvinylpyrrolidone was added, and the mixture was stirred and heated to 75°C. Then, 12g of p-trifluoromethylstyrene and 0.12g of azobisisobutyronitrile were added, and the reaction was continued for 18h. After the reaction was completed, the mixture was centrifuged, washed and dried to obtain fluorinated polystyrene-coated titanium dioxide material.

[0038] Step S3: Hexafluorobutanol was slowly heated to 80°C, and then isophorone diisocyanate was added dropwise. After the addition was complete, dibutyltin dilaurate was added, and the reaction was continued for 4 hours. After the reaction was completed, the product was washed and dried to obtain the terminal isocyanate product. Eugenol was added to tetrahydrofuran under nitrogen atmosphere, and after stirring evenly, the terminal isocyanate product and dibutyltin dilaurate were added. The reaction was stirred at 65°C for 5 hours. After the reaction was completed, the product was rotary evaporated, washed, and dried to obtain the terminal olefin fluorinated product. When preparing the terminal isocyanate product, the reaction molar ratio of hexafluorobutanol to isophorone diisocyanate was 0.95:1. When preparing the terminal olefin fluorinated product, the reaction molar ratio of the terminal isocyanate product to eugenol was 1:1.05.

[0039] Step S4: Dimethylaminoethyl methacrylate was added to acetone and stirred until homogeneous to obtain an acrylic acid solution; allyl chloride was added to acetone and stirred until homogeneous to obtain an allyl chloride solution; the allyl chloride solution was added dropwise to the acrylic acid solution, and the mixture was refluxed and stirred at 55°C for 9 hours. After the reaction was completed, the product was distilled under reduced pressure, washed, filtered, and dried to obtain the quaternary ammonium acrylate; the mass ratio of dimethylaminoethyl methacrylate to allyl chloride was 2:1.05.

[0040] Step S5: Add 5g of terminal olefin fluorination product, 4g of quaternary ammonium acrylate, and 3g of trifluoroethyl methacrylate to 110g of anhydrous ethanol, stir evenly, then add 6g of modified titanium dioxide, ultrasonically disperse for 40min, then add 0.12g of azobisisobutyronitrile, and reflux at 80℃ for 8h. After the reaction is completed, filter under reduced pressure, wash, and dry to obtain antibacterial low surface energy modified titanium dioxide.

[0041] Step S6: Mix 40g of hydroxyl-terminated polydimethylsiloxane, 0.7g of defoamer BYK066, and 0.25g of leveling agent 3700. After stirring and dispersing evenly, add 5g of fluorinated polystyrene-coated titanium dioxide material and 5g of antibacterial low surface energy modified titanium dioxide. Stir and disperse evenly to obtain a pretreated silicone coating. Then add 50g of solvent to the pretreated silicone coating and stir evenly. Add 2g of tetraethyl orthosilicate and 0.45g of dibutyltin dilaurate. Stir evenly to obtain a silicone drag-reducing coating. The solvent is a mixture of xylene, cyclohexanone, and ethanol in a mass ratio of 9:1:2.

[0042] Step 2: Mix 80g of polyurethane thermoplastic elastomer, 8g of magnesium hydroxide, 2g of stearic acid, and 3g of antioxidant 1010, and melt extrude and blow mold to form a film to obtain a TPU base film; laminate the PET release film coated with polyacrylate pressure-sensitive adhesive and the TPU base film together, and press them together to obtain a composite base film; coat the surface of the composite base film with an organosilicon drag-reducing coating, and cure at 30℃ for 10h to obtain the finished product.

[0043] Example 2: Step 1: Step S1: Methacryloxypropyltrimethoxysilane was added to anhydrous ethanol, stirred and dissolved, and then deionized water was added for pre-hydrolysis to obtain a silane coupling agent solution; nano-titanium dioxide was added to anhydrous ethanol, ultrasonically dispersed evenly, and then heated to 77°C. The silane coupling agent solution was then slowly added dropwise, and the reaction was continuously refluxed for 6.5 h. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain modified titanium dioxide; the reaction mass ratio of methacryloxypropyltrimethoxysilane to nano-titanium dioxide was 1.15:1; the mass-volume ratio of methacryloxypropyltrimethoxysilane, anhydrous ethanol, and deionized water was 1 g: 3.2 mL: 0.45 mL; and the mass-volume ratio of nano-titanium dioxide to anhydrous ethanol was 1 g: 67 mL.

[0044] Step S2: Under nitrogen atmosphere, 1.6g of modified titanium dioxide, 95g of anhydrous ethanol and 5g of deionized water were mixed and ultrasonically dispersed. Then, 2g of dispersant polyvinylpyrrolidone was added, and the mixture was stirred and heated to 72°C. Then, 12g of p-trifluoromethylstyrene and 0.12g of azobisisobutyronitrile were added, and the reaction was continued for 16h. After the reaction was completed, the mixture was centrifuged, washed and dried to obtain fluorinated polystyrene-coated titanium dioxide material.

[0045] Step S3: Hexafluorobutanol was slowly heated to 77°C, and then isophorone diisocyanate was added dropwise. After the addition was complete, dibutyltin dilaurate was added, and the reaction was continued for 3.5 h. After the reaction was completed, the product was washed and dried to obtain the terminal isocyanate product. Eugenol was added to tetrahydrofuran under nitrogen atmosphere, and after stirring evenly, the terminal isocyanate product and dibutyltin dilaurate were added. The reaction was stirred at 62°C for 4 h. After the reaction was completed, the product was rotary evaporated, washed, and dried to obtain the terminal olefin fluorinated product. When preparing the terminal isocyanate product, the reaction molar ratio of hexafluorobutanol to isophorone diisocyanate was 0.95:1. When preparing the terminal olefin fluorinated product, the reaction molar ratio of the terminal isocyanate product to eugenol was 1:1.05.

[0046] Step S4: Dimethylaminoethyl methacrylate was added to acetone and stirred until homogeneous to obtain an acrylic acid solution; allyl chloride was added to acetone and stirred until homogeneous to obtain an allyl chloride solution; the allyl chloride solution was added dropwise to the acrylic acid solution, and the mixture was refluxed and stirred at 52°C for 8 hours. After the reaction was completed, the product was distilled under reduced pressure, washed, filtered, and dried to obtain the quaternary ammonium acrylate; the mass ratio of dimethylaminoethyl methacrylate to allyl chloride was 2:1.05.

[0047] Step S5: Add 5g of terminal olefin fluorination product, 4g of quaternary ammonium acrylate, and 3g of trifluoroethyl methacrylate to 110g of anhydrous ethanol, stir evenly, then add 6g of modified titanium dioxide, ultrasonically disperse for 35min, then add 0.12g of azobisisobutyronitrile, reflux at 77℃ for 7h, after the reaction is completed, filter under reduced pressure, wash and dry to obtain antibacterial low surface energy modified titanium dioxide;

[0048] Step S6: Mix 40g of hydroxyl-terminated polydimethylsiloxane, 0.7g of defoamer BYK066, and 0.25g of leveling agent 3700. After stirring and dispersing evenly, add 5g of fluorinated polystyrene-coated titanium dioxide material and 5g of antibacterial low surface energy modified titanium dioxide. Stir and disperse evenly to obtain a pretreated silicone coating. Then add 50g of solvent to the pretreated silicone coating and stir evenly. Add 2g of tetraethyl orthosilicate and 0.45g of dibutyltin dilaurate. Stir evenly to obtain a silicone drag-reducing coating. The solvent is a mixture of xylene, cyclohexanone, and ethanol in a mass ratio of 9:1:2.

[0049] Step 2: Mix 80g of polyurethane thermoplastic elastomer, 8g of magnesium hydroxide, 2g of stearic acid, and 3g of antioxidant 1010, and melt extrude and blow mold to form a film to obtain a TPU base film; laminate the PET release film coated with polyacrylate pressure-sensitive adhesive and the TPU base film together, and press them together to obtain a composite base film; coat the surface of the composite base film with an organosilicon drag-reducing coating, and cure at 27℃ for 9 hours to obtain the finished product.

[0050] Example 3: Step 1: Step S1: Methacryloxypropyltrimethoxysilane was added to anhydrous ethanol, stirred and dissolved, and then deionized water was added for pre-hydrolysis to obtain a silane coupling agent solution; nano-titanium dioxide was added to anhydrous ethanol, ultrasonically dispersed evenly, and then heated to 75°C. The silane coupling agent solution was then slowly added dropwise, and the reaction was continuously refluxed for 6 hours. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain modified titanium dioxide; the reaction mass ratio of methacryloxypropyltrimethoxysilane to nano-titanium dioxide was 1.15:1; the mass-volume ratio of methacryloxypropyltrimethoxysilane, anhydrous ethanol, and deionized water was 1g:3.2mL:0.45mL; and the mass-volume ratio of nano-titanium dioxide to anhydrous ethanol was 1g:67mL.

[0051] Step S2: Under nitrogen atmosphere, 1.6g of modified titanium dioxide, 95g of anhydrous ethanol and 5g of deionized water were mixed and ultrasonically dispersed. Then, 2g of dispersant polyvinylpyrrolidone was added, and the mixture was stirred and heated to 70°C. Then, 12g of p-trifluoromethylstyrene and 0.12g of azobisisobutyronitrile were added, and the reaction was continued for 15h. After the reaction was completed, the mixture was centrifuged, washed and dried to obtain fluorinated polystyrene-coated titanium dioxide material.

[0052] Step S3: Hexafluorobutanol was slowly heated to 75°C, and then isophorone diisocyanate was added dropwise. After the addition was complete, dibutyltin dilaurate was added, and the reaction was continued for 3 hours. After the reaction was completed, the product was washed and dried to obtain the terminal isocyanate product. Eugenol was added to tetrahydrofuran under nitrogen atmosphere, and after stirring evenly, the terminal isocyanate product and dibutyltin dilaurate were added. The reaction was stirred at 60°C for 3 hours. After the reaction was completed, the product was rotary evaporated, washed, and dried to obtain the terminal olefin fluorinated product. When preparing the terminal isocyanate product, the reaction molar ratio of hexafluorobutanol to isophorone diisocyanate was 0.95:1. When preparing the terminal olefin fluorinated product, the reaction molar ratio of the terminal isocyanate product to eugenol was 1:1.05.

[0053] Step S4: Dimethylaminoethyl methacrylate was added to acetone and stirred until homogeneous to obtain an acrylic acid solution; allyl chloride was added to acetone and stirred until homogeneous to obtain an allyl chloride solution; the allyl chloride solution was added dropwise to the acrylic acid solution, and the mixture was refluxed and stirred at 50°C for 7 hours. After the reaction was completed, the product was distilled under reduced pressure, washed, filtered, and dried to obtain the quaternary ammonium acrylate; the mass ratio of dimethylaminoethyl methacrylate to allyl chloride was 2:1.05.

[0054] Step S5: Add 5g of terminal olefin fluorination product, 4g of quaternary ammonium acrylate, and 3g of trifluoroethyl methacrylate to 110g of anhydrous ethanol, stir evenly, then add 6g of modified titanium dioxide, ultrasonically disperse for 30min, then add 0.12g of azobisisobutyronitrile, reflux at 75℃ for 6h, after the reaction is completed, filter under reduced pressure, wash and dry to obtain antibacterial low surface energy modified titanium dioxide;

[0055] Step S6: Mix 40g of hydroxyl-terminated polydimethylsiloxane, 0.7g of defoamer BYK066, and 0.25g of leveling agent 3700. After stirring and dispersing evenly, add 5g of fluorinated polystyrene-coated titanium dioxide material and 5g of antibacterial low surface energy modified titanium dioxide. Stir and disperse evenly to obtain a pretreated silicone coating. Then add 50g of solvent to the pretreated silicone coating and stir evenly. Add 2g of tetraethyl orthosilicate and 0.45g of dibutyltin dilaurate. Stir evenly to obtain a silicone drag-reducing coating. The solvent is a mixture of xylene, cyclohexanone, and ethanol in a mass ratio of 9:1:2.

[0056] Step 2: Mix 80g of polyurethane thermoplastic elastomer, 8g of magnesium hydroxide, 2g of stearic acid, and 3g of antioxidant 1010, and melt extrude and blow mold to form a film to obtain a TPU base film; laminate the PET release film coated with polyacrylate pressure-sensitive adhesive and the TPU base film together, and press them together to obtain a composite base film; coat the surface of the composite base film with an organosilicon drag-reducing coating, and cure at 25℃ for 8 hours to obtain the finished product.

[0057] Comparative Example 1: The fluorinated polystyrene-coated titanium dioxide material was removed, and the rest was the same as in Example 1. The specific steps are as follows: Step 1: Step S1: Methacryloxypropyltrimethoxysilane was added to anhydrous ethanol, stirred and dissolved, and then deionized water was added for pre-hydrolysis to obtain a silane coupling agent solution; nano-titanium dioxide was added to anhydrous ethanol, ultrasonically dispersed evenly, and then heated to 80°C. The silane coupling agent solution was then slowly added dropwise, and the reaction was continuously refluxed for 7 hours. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain modified titanium dioxide; the reaction mass ratio of methacryloxypropyltrimethoxysilane to nano-titanium dioxide was 1.15:1; the mass-volume ratio of methacryloxypropyltrimethoxysilane, anhydrous ethanol, and deionized water was 1g:3.2mL:0.45mL; and the mass-volume ratio of nano-titanium dioxide to anhydrous ethanol was 1g:67mL.

[0058] Step S2: Hexafluorobutanol was slowly heated to 80°C, and then isophorone diisocyanate was added dropwise. After the addition was complete, dibutyltin dilaurate was added, and the reaction was continued for 4 hours. After the reaction was completed, the product was washed and dried to obtain the terminal isocyanate product. Eugenol was added to tetrahydrofuran under nitrogen atmosphere, and after stirring evenly, the terminal isocyanate product and dibutyltin dilaurate were added. The reaction was stirred at 65°C for 5 hours. After the reaction was completed, the product was rotary evaporated, washed, and dried to obtain the terminal olefin fluorinated product. When preparing the terminal isocyanate product, the reaction molar ratio of hexafluorobutanol to isophorone diisocyanate was 0.95:1. When preparing the terminal olefin fluorinated product, the reaction molar ratio of the terminal isocyanate product to eugenol was 1:1.05.

[0059] Step S3: Dimethylaminoethyl methacrylate was added to acetone and stirred until homogeneous to obtain an acrylic acid solution; allyl chloride was added to acetone and stirred until homogeneous to obtain an allyl chloride solution; the allyl chloride solution was added dropwise to the acrylic acid solution, and the mixture was refluxed and stirred at 55°C for 9 hours. After the reaction was completed, the mixture was distilled under reduced pressure, washed, filtered, and dried to obtain the quaternary ammonium acrylate; the mass ratio of dimethylaminoethyl methacrylate to allyl chloride was 2:1.05.

[0060] Step S4: Add 5g of terminal olefin fluorination product, 4g of quaternary ammonium acrylate, and 3g of trifluoroethyl methacrylate to 110g of anhydrous ethanol, stir evenly, then add 6g of modified titanium dioxide, ultrasonically disperse for 40min, then add 0.12g of azobisisobutyronitrile, and reflux at 80℃ for 8h. After the reaction is completed, filter under reduced pressure, wash, and dry to obtain antibacterial low surface energy modified titanium dioxide.

[0061] Step S5: Mix 40g of hydroxyl-terminated polydimethylsiloxane, 0.7g of defoamer BYK066, and 0.25g of leveling agent 3700. After stirring and dispersing evenly, add 5g of antibacterial low surface energy modified titanium dioxide and stir and disperse evenly to obtain a pretreated silicone coating. Then add 50g of solvent to the pretreated silicone coating and stir evenly. After stirring evenly, add 2g of tetraethyl orthosilicate and 0.45g of dibutyltin dilaurate and stir evenly to obtain a silicone drag-reducing coating. The solvent is a mixture of xylene, cyclohexanone, and ethanol in a mass ratio of 9:1:2.

[0062] Step 2: Mix 80g of polyurethane thermoplastic elastomer, 8g of magnesium hydroxide, 2g of stearic acid, and 3g of antioxidant 1010, and melt extrude and blow mold to form a film to obtain a TPU base film; laminate the PET release film coated with polyacrylate pressure-sensitive adhesive and the TPU base film together, and press them together to obtain a composite base film; coat the surface of the composite base film with an organosilicon drag-reducing coating, and cure at 30℃ for 10h to obtain the finished product.

[0063] Comparative Example 2: The antibacterial low surface energy modified titanium dioxide was removed, and the rest was the same as in Example 1. The specific steps are as follows: Step 1: Step S1: Methacryloxypropyltrimethoxysilane was added to anhydrous ethanol, stirred and dissolved, and then deionized water was added for pre-hydrolysis to obtain a silane coupling agent solution; nano-titanium dioxide was added to anhydrous ethanol, ultrasonically dispersed evenly, and then heated to 80°C. The silane coupling agent solution was then slowly added dropwise, and the reaction was continuously refluxed for 7 hours. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain modified titanium dioxide; the reaction mass ratio of methacryloxypropyltrimethoxysilane to nano-titanium dioxide was 1.15:1; the mass-volume ratio of methacryloxypropyltrimethoxysilane, anhydrous ethanol, and deionized water was 1g:3.2mL:0.45mL; and the mass-volume ratio of nano-titanium dioxide to anhydrous ethanol was 1g:67mL.

[0064] Step S2: Under nitrogen atmosphere, 1.6g of modified titanium dioxide, 95g of anhydrous ethanol and 5g of deionized water were mixed and ultrasonically dispersed. Then, 2g of dispersant polyvinylpyrrolidone was added, and the mixture was stirred and heated to 75°C. Then, 12g of p-trifluoromethylstyrene and 0.12g of azobisisobutyronitrile were added, and the reaction was continued for 18h. After the reaction was completed, the mixture was centrifuged, washed and dried to obtain fluorinated polystyrene-coated titanium dioxide material.

[0065] Step S3: Mix 40g of hydroxyl-terminated polydimethylsiloxane, 0.7g of defoamer BYK066, and 0.25g of leveling agent 3700. After stirring and dispersing evenly, add 5g of fluorinated polystyrene-coated titanium dioxide material and stir and disperse evenly to obtain a pretreated silicone coating. Then add 50g of solvent to the pretreated silicone coating and stir evenly. After stirring evenly, add 2g of tetraethyl orthosilicate and 0.45g of dibutyltin dilaurate and stir evenly to obtain a silicone drag-reducing coating. The solvent is a mixture of xylene, cyclohexanone, and ethanol in a mass ratio of 9:1:2.

[0066] Step 2: Mix 80g of polyurethane thermoplastic elastomer, 8g of magnesium hydroxide, 2g of stearic acid, and 3g of antioxidant 1010, and melt extrude and blow mold to form a film to obtain a TPU base film; laminate the PET release film coated with polyacrylate pressure-sensitive adhesive and the TPU base film together, and press them together to obtain a composite base film; coat the surface of the composite base film with an organosilicon drag-reducing coating, and cure at 30℃ for 10h to obtain the finished product.

[0067] Drag reduction test: An organosilicon drag-reducing coating was applied to the surface of the composite base film and cured to obtain the finished composite drag-reducing film as a sample. 2 μL of deionized water was added to the surface of the sample coating. After stabilizing for 5 seconds, the contact angle was measured using a contact angle meter. The contact angle of the droplet at three different positions was recorded and the average value was taken.

[0068] Weather resistance test: An organosilicon drag-reducing coating was applied to the surface of the composite base film and cured to obtain the finished composite drag-reducing film as a sample. The prepared sample was placed in a UV aging test chamber, and the relative humidity inside the chamber was adjusted to 50% for a 2000-hour aging test. During the test, the operating status of the test chamber was checked regularly to ensure that all parameters remained stable within the set range. After the aging test, the sample was removed from the test chamber and placed at room temperature for 24 hours to allow it to recover to a stable state before observing the sample surface.

[0069] Bactericidal test: A silicone drag-reducing coating was applied to the surface of the composite base film, and the resulting composite drag-reducing film was cured and used as the sample. A prepared *E. coli* suspension was dropped onto the sample surface, and then covered with a sterile polypropylene film to form a closed contact system. The system was continuously incubated at 37°C for 24 hours. After incubation, the sample was washed and shaken with PBS buffer to obtain the *E. coli* reaction solution. The *E. coli* reaction solution was added to a solid culture medium and incubated at 37°C for 24 hours. The number of *E. coli* bacteria was then determined using a colony counter. The composite base film without the silicone drag-reducing coating was used as a blank sample, and the number of *E. coli* bacteria was tested accordingly. The antibacterial rate was then calculated using the formula. The results are shown in the table below:

[0070]

[0071] Conclusion: In Examples 1-3, the dosage remained unchanged, with only some reaction parameters modified. Experimental data showed no significant fluctuations in the performance of the samples.

[0072] Comparative Example 1: The fluorinated polystyrene-coated titanium dioxide material was removed, while the rest remained the same as in Example 1. Experimental data showed that, compared to Example 1, the water contact angle decreased to 105°, the sterilization rate decreased to 90.7%, and the weather resistance surface test results were as follows: the sample surface showed obvious and numerous blisters, as well as powdering and fading. The reason for this is that coating the titanium dioxide surface with fluorinated polystyrene creates a stable structure through polymerization, making the molecular structure less susceptible to damage under ultraviolet radiation, thus maintaining the material's stable performance and exhibiting excellent UV resistance. Furthermore, the fluorinated groups are evenly distributed on the material surface, fully utilizing the low surface energy characteristic. Low surface energy also effectively prevents bacterial growth and adhesion, contributing to improved antibacterial properties. Therefore, removing the fluorinated polystyrene resulted in a lower water contact angle, a lower sterilization rate, and poorer weather resistance surface test results.

[0073] Comparative Example 2: The antibacterial low surface energy modified titanium dioxide was removed, while the rest remained the same as in Example 1. Experimental data showed that compared to Example 1, the water contact angle decreased to 102°, the bactericidal rate decreased to 82.2%, and the weather resistance surface test results were as follows: The sample surface showed significant and widespread blistering, as well as powdering and fading. The reason for this was that during the polymerization reaction, the quaternary ammonium acrylate, the fluorinated products of the terminal olefins, and trifluoroethyl methacrylate polymerized together on the modified titanium dioxide surface to form a polymer network. The polymer coated the modified titanium dioxide surface, forming a high-performance protective layer. Therefore, removing this layer resulted in a lower water contact angle, a lower bactericidal rate, and poorer weather resistance surface test results.

[0074] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process method article or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process method article or apparatus.

[0075] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a UV resistant antioxidant multilayer composite drag reducing film, characterized in that: Comprising the following steps: Step one: mix the hydroxyl-terminated polydimethylsiloxane, defoaming agent, leveling agent, add fluorine-containing polystyrene coated titanium dioxide material, antibacterial low surface energy modified titanium dioxide after stirring and dispersing uniformly, and then add the pretreated silicone coating; Then add the solvent to the pretreated silicone coating, stir uniformly, then add tetraethyl orthosilicate and dibutyltin dilaurate, stir uniformly, and then get the silicone drag reduction coating; The content of each component of the silicone drag reduction coating is: 40-50 parts of hydroxyl-terminated polydimethylsiloxane, 0.7-0.8 parts of defoaming agent, 0.25-0.30 parts of leveling agent, 5-7 parts of fluorine-containing polystyrene coated titanium dioxide material, 5-7 parts of antibacterial low surface energy modified titanium dioxide, 50-60 parts of solvent, 2-3 parts of tetraethyl orthosilicate, and 0.45-0.50 parts of dibutyltin dilaurate; The preparation process of the fluorine-containing polystyrene coated titanium dioxide material is: Step S1: add methacryloxypropyl trimethoxysilane to anhydrous ethanol, stir and dissolve, then add deionized water for pre-hydrolysis to obtain a silane coupling agent solution; Add nano titanium dioxide to anhydrous ethanol, ultrasonic dispersion, then heat to 75-80℃, slowly add the silane coupling agent solution, continue reflux reaction for 6-7h, after reaction, centrifugal, washing, drying to obtain modified titanium dioxide; Step S2: mix the modified titanium dioxide, anhydrous ethanol and deionized water under nitrogen environment, ultrasonic dispersion, then add the dispersant polyvinylpyrrolidone, stir and heat to 70-75℃, then add p-trifluoromethyl styrene and azobisisobutyronitrile, continue to react for 15-18h, after reaction, centrifugal, washing, drying to obtain the fluorine-containing polystyrene coated titanium dioxide material; The preparation process of the antibacterial low surface energy modified titanium dioxide is: Step S1: add methacryloxypropyl trimethoxysilane to anhydrous ethanol, stir and dissolve, then add deionized water for pre-hydrolysis to obtain a silane coupling agent solution; Add nano titanium dioxide to anhydrous ethanol, ultrasonic dispersion, then heat to 75-80℃, slowly add the silane coupling agent solution, continue reflux reaction for 6-7h, after reaction, centrifugal, washing, drying to obtain modified titanium dioxide; Step S2: add the end olefin fluorination product, quaternary ammonium salt of acrylic acid and trifluoroethyl methacrylate to anhydrous ethanol, stir uniformly, then add the modified titanium dioxide, ultrasonic dispersion for 30-40min, then add azobisisobutyronitrile, reflux reaction at 75-80℃ for 6-8h, after reaction, reduce pressure filtration, washing, drying to obtain the antibacterial low surface energy modified titanium dioxide; Step two: mix the polyurethane thermoplastic elastomer, flame retardant, stearic acid and antioxidant, melt extrusion, blow molding to obtain a TPU base film; Laminate the PET release film coated with adhesive and the TPU base film, heat press to obtain a composite base film; Coating the silicone drag reduction coating on the surface of the composite base film, curing at 25-30℃ for 8-10h to obtain the finished product.

2. The method for preparing the ultraviolet resistant and oxidation resistant multilayer composite drag-reducing film according to claim 1, characterized in that: The TPU base film contains the following components: 80-90 parts by mass of polyurethane thermoplastic elastomer, 8-10 parts by mass of flame retardant, 2-3 parts by mass of stearic acid, and 3-4 parts by mass of antioxidant.

3. The method of claim 1, wherein the method further comprises the step of: 3-1) coating the UV resistant and antioxidant multilayer composite drag reduction film on the surface of the object. In step S1, the reaction mass ratio of methacryloxypropyl trimethoxysilane to nano-titanium dioxide is (1.1-1.2):1; the mass-volume ratio of methacryloxypropyl trimethoxysilane, anhydrous ethanol and deionized water is 1g:(3.0-3.5)mL:0.45mL; the mass-volume ratio of nano-titanium dioxide and anhydrous ethanol is 1g:(65-70)mL. In step S2, the raw material for preparing the fluorine-containing polystyrene-coated titanium dioxide material contains the following components: 1.6-1.8 parts by mass of modified titanium dioxide, 95-100 parts by mass of anhydrous ethanol, 5-7 parts by mass of deionized water, 2-3 parts by mass of dispersant polyvinylpyrrolidone, 12-14 parts by mass of p-trifluoromethyl styrene, and 0.12-0.14 parts by mass of azobisisobutyronitrile.

4. The method of claim 1, wherein the method further comprises the step of: 4.

1. applying a layer of a UV resistant antioxidant material on the surface of the base layer. In step S1, the reaction mass ratio of methacryloxypropyl trimethoxysilane to nano-titanium dioxide is (1.1-1.2):1; the mass-volume ratio of methacryloxypropyl trimethoxysilane, anhydrous ethanol and deionized water is 1g:(3.0-3.5)mL:0.45mL; the mass-volume ratio of nano-titanium dioxide and anhydrous ethanol is 1g:(65-70)mL. In step S2, the raw material for preparing the antibacterial low-surface-energy modified titanium dioxide contains the following components: 5-7 parts by mass of terminal olefin fluorination product, 4-5 parts by mass of quaternary ammonium salt of acrylic acid, 3.0-3.5 parts by mass of trifluoroethyl methacrylate, 110-130 parts by mass of anhydrous ethanol, 6-8 parts by mass of modified titanium dioxide, and 0.12-0.15 parts by mass of azobisisobutyronitrile.

5. The method of claim 1, wherein the method further comprises: coating the UV resistant and antioxidant multilayer composite drag reduction film on the surface of the object. The preparation process of the terminal olefin fluorination product is as follows: slowly heat hexafluorobutanol to 75-80℃, then add isophorone diisocyanate dropwise, after the addition is completed, add dibutyltin dilaurate, and continue to react for 3-4h; after the reaction is completed, wash and dry to obtain a terminal isocyanate product; under a nitrogen environment, add eugenol to tetrahydrofuran, stir uniformly, then add the terminal isocyanate product and dibutyltin dilaurate, and stir to react at 60-65℃ for 3-5h; after the reaction is completed, rotary evaporation, washing and drying to obtain the terminal olefin fluorination product.

6. The method of claim 5, wherein the method further comprises the step of: 5 applying a protective layer on the surface of the multilayer composite UV resistant and antioxidant drag reduction film. In the preparation of the terminal isocyanate product, the reaction molar ratio of hexafluorobutanol to isophorone diisocyanate is (0.9-1.0):1; in the preparation of the terminal olefin fluorination product, the reaction molar ratio of the terminal isocyanate product to eugenol is 1:(1.0-1.1).

7. The method of claim 1, wherein the method further comprises: coating the UV resistant and antioxidant multilayer composite drag reduction film on the surface of the object. The preparation process of the quaternary ammonium salt of acrylic acid is as follows: add dimethylaminoethyl methacrylate to acetone, stir uniformly to obtain an acrylic acid solution; add chloroacryl to acetone, stir uniformly to obtain a chloroacryl solution; add the chloroacryl solution dropwise to the acrylic acid solution, reflux and stir to react at 50-55℃ for 7-9h; after the reaction is completed, perform reduced pressure distillation, washing, suction filtration and drying to obtain the quaternary ammonium salt of acrylic acid; the reaction mass ratio of dimethylaminoethyl methacrylate to chloroacryl is 2:(1.0-1.1).

8. A UV resistant antioxidant multilayered composite drag reducing film characterized in that, obtained according to the process of any one of claims 1 to 7.

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