Polyurethane protective adhesive tape for aviation and preparation method thereof

Abstract

The invention discloses a polyurethane protective adhesive tape for aviation and a preparation method thereof, and relates to the technical field of adhesives. When the polyurethane protective adhesive tape for aviation is prepared, polyester glycol, an ultraviolet absorption monomer, 3-(4-pyridyl) pentane-1, 5-diol, 1, 4-butanediol and isophorone diisocyanate are polymerized to prepare polyurethane; the preparation method comprises the following steps: carrying out a reaction on polyurethane and 2-bromoethyl acrylate to prepare modified polyurethane; enabling the pretreated magnesium hydroxide to react with 3-epoxypropoxy-1, 1, 3, 3-tetramethyldisiloxane and ammonia water in sequence, so as to obtain modified magnesium hydroxide; the modified polyurethane and the modified magnesium hydroxide are mixed and then subjected to compression molding to prepare a polyurethane film; and coating a polyurethane film with the polyacrylate glue solution, and drying to obtain the polyurethane protective adhesive tape for aviation. The polyurethane protective adhesive tape for aviation prepared by the invention has excellent flame-retardant, anti-aging, antibacterial and self-repairing properties.

Description

Technical Field

[0001] The present invention relates to the technical field of adhesives, in particular to a polyurethane protective tape for aviation and a preparation method thereof. Background Art

[0002] In aircraft cabins, polyurethane tape can be used to cover wet areas such as cabin toilets and kitchen floor panels, preventing liquid penetration and corrosion through its barrier properties. It can also be used to fill gaps in doors and windows and irregular joints in the cabin to prevent foreign matter from penetrating and maintain airtightness to meet aviation safety standards.

[0003] Polyurethane tapes produced using existing technologies are flammable, prone to aging, and have poor antibacterial properties. Conventional polyurethane tapes are primarily composed of elements such as C, H, O, and N, have a low limiting oxygen index, are easily flammable, and pose safety risks during use. Ultraviolet radiation intensity increases with altitude, and polyurethane tapes in aircraft cabins are susceptible to aging under the influence of UV rays, resulting in performance degradation. Over long-term use, polyurethane tapes are also susceptible to contact with various liquids and foreign matter, leading to bacterial growth. These deficiencies make it difficult for polyurethane tapes produced using existing technologies to meet market demand. Therefore, it is necessary to improve existing technologies and develop polyurethane protective tapes with excellent flame retardancy, anti-aging, and antibacterial properties. Summary of the Invention

[0004] The purpose of the present invention is to provide a polyurethane protective tape for aviation and a preparation method thereof, so as to solve the problems existing in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: A polyurethane protective tape for aviation, comprising the following steps: polymerizing polyester diol, an ultraviolet absorbing monomer, 3-(4-pyridyl)pentane-1,5-diol, 1,4-butanediol, and isophorone diisocyanate to produce polyurethane; reacting polyurethane with 2-bromoethyl acrylate to produce modified polyurethane; reacting pre-modified magnesium hydroxide with ammonia water to produce modified magnesium hydroxide; mixing the modified polyurethane and modified magnesium hydroxide and then subjecting the mixture to compression molding to produce a polyurethane film; and coating the polyurethane film with a polyacrylate adhesive and drying the resulting tape. The ultraviolet absorption monomer is prepared by reacting 4,4'-dichlorobenzophenone with diethyl benzylphosphonate and ethylene glycol in sequence; The pre-modified magnesium hydroxide is prepared by reacting pre-treated magnesium hydroxide and 3-glycidoxy-1,1,3,3-tetramethyldisiloxane; The pretreated magnesium hydroxide is prepared by reacting magnesium hydroxide and vinyltriethoxysilane; The polyacrylate adhesive is prepared by mixing polyacrylate emulsion, aluminum acetylacetonate and acetone.

[0006] A method for preparing a polyurethane protective tape for aviation, comprising the following steps: (1) Polyurethane and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1:(6-8), stirred at 40-50°C and 100-200 r / min for 8-10 min, 2-bromoethyl acrylate (1.2-1.4 times the mass of polyurethane) was added, the temperature was raised to 58-62°C, and the stirring reaction was continued for 2-3 h. N,N-dimethylformamide was removed by vacuum rotary evaporation, and the mixture was washed with anhydrous ethanol for 3-5 times. The mixture was dried at 60-70°C under vacuum conditions for 10-12 h to obtain modified polyurethane. (2) Pre-modified magnesium hydroxide and tetrahydrofuran were mixed uniformly in a mass ratio of 1:(19~21), and an aqueous ammonia solution with a mass fraction of 18%~22% of 8~10 times the mass of the pre-modified magnesium hydroxide was added, and the mixture was stirred and refluxed at 60~64°C and 200~300r / min for 4~5h, filtered, washed with deionized water for 3~5 times, and dried at 50~60°C under vacuum conditions for 8~10h to obtain modified magnesium hydroxide; (3) The modified polyurethane and modified magnesium hydroxide were mixed evenly in a mass ratio of 1:(0.05~0.06), placed in an internal mixer, stirred at 180~190℃, 200~300r / min for 16~18min, placed in a calender for calendering, and after calendering into a film, allowed to stand at 116~120℃ for 2~3h, cooled to room temperature, and a polyurethane film was obtained; a 500μm I-shaped coater was used to coat the polyurethane glue on the polyurethane film, allowed to stand at room temperature for 20~30min, allowed to stand at 80~90℃ for 60~70min, heated to 110~120℃, allowed to stand for 70~80min, and cooled to room temperature to obtain a polyurethane protective tape for aviation.

[0007] As an optimization, the preparation method of the polyurethane in step (1) is as follows: polyester diol, ultraviolet absorption monomer, 3-(4-pyridyl)pentane-1,5-diol, 1,4-butanediol, N,N-dimethylformamide are mixed uniformly in a mass ratio of 1:(0.6~0.8):(0.5~0.6):(0.3~0.4):(12~14), stirred at 48~52°C and 200~300r / min for 16~18min, and added Add 3-3.2 times the mass of isophorone diisocyanate and 0.03-0.05 times the mass of polyester diol of dibutyltin dilaurate, continue stirring and reacting for 24-26 minutes, raise the temperature to 98-100°C, continue stirring and reacting for 4-5 hours, add 1-1.2 times the mass of isophorone diisocyanate of anhydrous ethanol and mix evenly, continue stirring for 5-7 minutes, and dry at 70-80°C under vacuum conditions for 10-12 hours to obtain polyurethane.

[0008] As an optimization, the CAS number of the 3-(4-pyridyl)pentane-1,5-diol is 26684-57-1; the structural formula is: .

[0009] As an optimization, the polyester diol has a model of Oxyester T1136, which was purchased from Shenzhen Longdi Chemical Co., Ltd.

[0010] As an optimization, the preparation method of the ultraviolet absorbing monomer is as follows: dichlorotriphenylethylene and toluene are mixed uniformly in a mass ratio of 1:(6~7) to prepare a dichlorotriphenylethylene solution; ethylene glycol, triethylamine, and toluene with a molar amount of 1.1~1.2 times that of dichlorotriphenylethylene are mixed uniformly in a mass ratio of 1:(0.04~0.06):(8~10), and the dichlorotriphenylethylene solution is added dropwise at a uniform speed within 20 minutes at 50~60°C and 200~300r / min stirring conditions. After the addition is completed, the temperature is raised to 64~66°C, the stirring reaction is continued for 3~4 hours, and the ultraviolet absorbing monomer is prepared by drying at 50~60°C for 8~10 hours under vacuum conditions to obtain the ultraviolet absorbing monomer.

[0011] As an optimization, the preparation method of the dichlorotriphenylethylene is as follows: 4,4'-dichlorobenzophenone and diethyl benzylphosphonate are added in a molar ratio of 1:1 to tetrahydrofuran (14 to 16 times the mass of 4,4'-dichlorobenzophenone), stirred at 0 to 2°C and 200 to 300 r / min for 8 to 10 minutes, potassium tert-butoxide (0.03 to 0.05 times the mass of 4,4'-dichlorobenzophenone) is added, stirring is continued for 6 to 8 minutes, the temperature is raised to 24 to 26°C, stirring is continued for 2 to 3 hours, tetrahydrofuran is removed by vacuum rotary evaporation, an equal volume of deionized water and ethyl acetate are added, mixed evenly, allowed to stand and separate, the organic phase is taken, and dried at 50 to 60°C under vacuum conditions for 8 to 10 hours to obtain dichlorotriphenylethylene.

[0012] As an optimization, the reaction process of the ultraviolet absorbing monomer is as follows: .

[0013] As an optimization, the preparation method of the pre-modified magnesium hydroxide in step (2) is as follows: pre-treated magnesium hydroxide, 3-epoxypropoxy-1,1,3,3-tetramethyldisiloxane and toluene are mixed uniformly in a mass ratio of 1:(3~4):(18~22), 0.05~0.07 times the mass of the pre-treated magnesium hydroxide is added with chloroplatinic acid, and the mixture is stirred at 70~80°C and 300~400r / min for 3~4h, filtered, washed with anhydrous ethanol 3~5 times, and dried at 60~70°C under vacuum conditions for 8~9h to obtain pre-modified magnesium hydroxide.

[0014] As an optimization, the CAS number of the 3-glycidoxy-1,1,3,3-tetramethyldisiloxane is 17980-29-9; the structural formula is: .

[0015] As an optimization, the preparation method of the pretreated magnesium hydroxide is as follows: vinyltriethoxysilane and anhydrous ethanol are mixed evenly in a mass ratio of 1: (7~8) to prepare a surface treatment liquid; magnesium hydroxide and deionized water are mixed evenly in a mass ratio of 1: (20~22), ultrasonically dispersed for 50~60 minutes, heated to 70~80°C, and under stirring conditions of 300~400r / min, the surface treatment liquid with a mass of 10~12 times that of the magnesium hydroxide is uniformly added dropwise within 15 minutes. After the addition is completed, the stirring reaction is continued for 3~4 hours, filtered, washed with anhydrous ethanol 3~5 times, and dried at 60~70°C under vacuum conditions for 7~8 hours to obtain pretreated magnesium hydroxide.

[0016] As an optimization, the particle size of the magnesium hydroxide is 1000 mesh, which is purchased from Suzhou Gajisen New Material Technology Co., Ltd.

[0017] As an optimization, the process parameters of the calendering molding in step (3) are: setting the temperature of the calender to 180~182℃ and the pressure to 30~32MPa.

[0018] As an optimization, the preparation method of the polyacrylate adhesive in step (3) is as follows: polyacrylate emulsion, aluminum acetylacetonate, and acetone are uniformly mixed in a mass ratio of 1:(0.04~0.06):(1.1~1.2), and deaerated in a vacuum degassing machine at 1000~1200 r / min for 1~2 min to obtain the polyacrylate adhesive.

[0019] As an optimization, the polyacrylate emulsion has a model of HG-100 and was purchased from Jiangsu Shengke New Materials Co., Ltd.

[0020] Compared with the prior art, the present invention has the following beneficial effects: The invention prepares a polyurethane protective tape for aviation by reacting 4,4'-dichlorobenzophenone and diethyl benzylphosphonate to obtain dichlorotriphenylethylene; reacting dichlorotriphenylethylene and ethylene glycol to obtain an ultraviolet absorption monomer; polymerizing polyester diol, the ultraviolet absorption monomer, 3-(4-pyridyl)pentane-1,5-diol, 1,4-butanediol and isophorone diisocyanate to obtain polyurethane; reacting polyurethane and 2-bromoethyl acrylate to obtain modified polyurethane; reacting magnesium hydroxide and vinyltriethoxysilane to obtain pretreated magnesium hydroxide; reacting pretreated magnesium hydroxide and 3-glycidoxy-1,1,3,3-tetramethyldisiloxane to obtain premodified magnesium hydroxide; reacting premodified magnesium hydroxide and ammonia water to obtain modified magnesium hydroxide; mixing the modified polyurethane and the modified magnesium hydroxide and then performing compression molding to obtain a polyurethane film; coating a polyacrylate adhesive on the polyurethane film, and drying the mixture to obtain the polyurethane protective tape for aviation.

[0021] First, 4,4'-dichlorobenzophenone and diethyl benzylphosphonate are subjected to a Horner-Wadsworth-Emmons (HWE) olefination reaction to produce dichlorotriphenylethylene. Dichlorotriphenylethylene is then reacted with ethylene glycol to produce a UV-absorbing monomer. The hydroxyl groups introduced at both ends of the UV-absorbing monomer can participate in the polymerization reaction of polyurethane, introducing a triphenylethylene structure into the main chain of the polyurethane molecule. The triphenylethylene structure can undergo a photocyclization reaction under the action of ultraviolet light and a ring-opening reaction under the action of visible light. This reversible cyclization reaction can absorb ultraviolet light and release the ultraviolet light energy in a harmless form, thereby giving the aviation polyurethane protective tape excellent anti-aging properties. The mechanism of action is as follows: .

[0022] Secondly, polyester diol, UV absorbing monomer, 3-(4-pyridyl)pentane-1,5-diol, 1,4-butanediol and isophorone diisocyanate are polymerized to prepare polyurethane, and a pyridine structure is introduced into the side chain of the polyurethane molecule; the pyridine structure introduced into the side chain of the polyurethane molecule is reacted with 2-bromoethyl acrylate to prepare a modified polyurethane; pyridinium salt is generated on the side chain of the modified polyurethane molecule, and an acrylate structure is introduced; the pyridinium salt can improve the antibacterial properties of aviation polyurethane protective tape; the acrylate structure can undergo a thermally reversible Aza-Michael addition reaction with the β-hydroxyamine structure introduced on the modified magnesium hydroxide to form a dynamic covalent β-hydroxyester crosslink. This dynamic covalent β-hydroxyester crosslink structure will break at high temperature and recombine when the temperature drops, thereby giving the aviation polyurethane protective tape thermal responsive self-healing properties. The mechanism of action is as follows: .

[0023] Finally, magnesium hydroxide and vinyltriethoxysilane are reacted to prepare pretreated magnesium hydroxide, and a carbon-carbon double bond is introduced into the pretreated magnesium hydroxide; the carbon-carbon double bond on the pretreated magnesium hydroxide undergoes a silylation reaction with the Si-H bond on 3-epoxypropoxy-1,1,3,3-tetramethyldisiloxane to prepare premodified magnesium hydroxide, and Si-O bonds and epoxy groups are introduced into the premodified magnesium hydroxide. The introduction of Si-O bonds can improve the flame retardant properties of polyurethane protective tape for aviation; the epoxy group on the premodified magnesium hydroxide undergoes a ring-opening reaction with ammonia water to prepare modified magnesium hydroxide, and a β-hydroxyamine structure is generated on the modified magnesium hydroxide; the modified magnesium hydroxide The β-hydroxyamine structure generated on magnesium can undergo a thermally reversible Aza-Michael addition reaction with the acrylate structure introduced on the side chain of the modified polyurethane molecule to form a dynamic covalent β-hydroxyester crosslink. This dynamic covalent β-hydroxyester crosslink structure will break at high temperatures and recombine when the temperature drops, thereby giving the aviation polyurethane protective tape thermal responsive self-healing properties; magnesium hydroxide is an inorganic flame retardant material that can release water vapor during combustion, promote carbonization, decompose and absorb heat to improve the flame retardant properties of aviation polyurethane protective tape. Surface modification of magnesium hydroxide can improve the compatibility between magnesium hydroxide and polyurethane. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] Example 1: A method for preparing a polyurethane protective tape for aviation, comprising the following steps: (1) Add 4,4'-dichlorobenzophenone and diethyl benzylphosphonate in a molar ratio of 1:1 to tetrahydrofuran (14 times the mass of 4,4'-dichlorobenzophenone), stir at 0°C, 200 r / min for 10 min, add potassium tert-butoxide (0.03 times the mass of 4,4'-dichlorobenzophenone), continue stirring for 8 min, heat to 24°C, continue stirring for 3 h, remove tetrahydrofuran by vacuum rotary evaporation, add equal volumes of deionized water and ethyl acetate, mix well, let stand and separate, take the organic phase, and heat at 50°C under vacuum. Dry for 10 hours to obtain dichlorotriphenylethylene; mix dichlorotriphenylethylene and toluene at a mass ratio of 1:6 to prepare a dichlorotriphenylethylene solution; mix ethylene glycol (1.1 times the molar amount of dichlorotriphenylethylene), triethylamine, and toluene at a mass ratio of 1:0.04:8, and add the dichlorotriphenylethylene solution dropwise at a constant speed over 20 minutes at 50°C and 200 r / min stirring conditions. After the addition is complete, heat to 64°C, continue stirring and react for 4 hours, and dry at 50°C under vacuum conditions for 10 hours to obtain a UV absorbing monomer; (2) Polyester diol, UV absorbing monomer, 3-(4-pyridyl)pentane-1,5-diol, 1,4-butanediol, N,N-dimethylformamide were mixed in a mass ratio of 1:0.6:0.5:0.3:12, stirred at 48 ° C, 200 r / min for 18 min, and isophorone diisocyanate (3 times the mass of polyester diol) and dibutyltin dilaurate (0.03 times the mass of polyester diol) were added. The reaction was continued with stirring for 26 min, and the temperature was raised to 98 ° C, and the reaction was continued with stirring for 5 h. Isophorone diisocyanate was added. The polyurethane was mixed evenly with anhydrous ethanol 1 times the mass of the ester, and the mixture was stirred for 7 minutes. The mixture was dried at 70°C for 12 hours under vacuum conditions to obtain polyurethane. Polyurethane and N,N-dimethylformamide were mixed evenly in a mass ratio of 1:6, stirred at 40°C and 100 r / min for 10 minutes, 2-bromoethyl acrylate 1.2 times the mass of the polyurethane was added, the mixture was heated to 58°C, and the mixture was stirred for 3 hours. N,N-dimethylformamide was removed by vacuum rotary evaporation, and the mixture was washed with anhydrous ethanol 3 times. The mixture was dried at 60°C for 12 hours under vacuum conditions to obtain modified polyurethane. (3) Vinyl triethoxysilane and anhydrous ethanol were mixed at a mass ratio of 1:7 to prepare a surface treatment liquid; magnesium hydroxide and deionized water were mixed at a mass ratio of 1:20 to prepare a surface treatment liquid; ultrasonic dispersion was performed for 50 minutes, the temperature was raised to 70 ° C, and under the stirring condition of 300 r / min, the surface treatment liquid with a mass 10 times of the mass of magnesium hydroxide was added dropwise at a constant speed within 15 minutes. After the addition was completed, the stirring reaction was continued for 4 hours, filtered, washed with anhydrous ethanol for 3 times, and dried at 60 ° C for 8 hours under vacuum conditions to prepare pretreated magnesium hydroxide; pretreated magnesium hydroxide, 3-glycidoxy-1,1,3,3-tetramethyldisiloxane, methyl Benzene was mixed evenly in a mass ratio of 1:3:18, chloroplatinic acid with a mass fraction of 0.05 times that of the pretreated magnesium hydroxide was added, and the mixture was stirred at 70°C and 300r / min for 4h, filtered, washed with anhydrous ethanol 3 times, and dried at 60°C for 9h under vacuum conditions to obtain pre-modified magnesium hydroxide; pre-modified magnesium hydroxide and tetrahydrofuran were mixed evenly in a mass ratio of 1:19, and an 18% ammonia aqueous solution with a mass fraction of 8 times that of the pre-modified magnesium hydroxide was added, and the mixture was stirred and refluxed at 60°C and 200r / min for 5h, filtered, washed with deionized water 3 times, and dried at 50°C for 10h under vacuum conditions to obtain modified magnesium hydroxide; (4) The modified polyurethane and modified magnesium hydroxide were mixed evenly in a mass ratio of 1:0.05, placed in an internal mixer, stirred at 180°C and 200 r / min for 18 minutes, placed in a calender for calendering, and the temperature of the calender was set to 180°C and the pressure was set to 30 MPa. After calendering, the film was allowed to stand at 116°C for 3 hours, cooled to room temperature, and a polyurethane film was obtained; polyacrylate emulsion, aluminum acetylacetonate, and acetone were mixed evenly in a mass ratio of 1:0.04:1.1, degassed in a vacuum degassing machine at 1000 r / min for 2 minutes to obtain a polyacrylate adhesive; the polyacrylate adhesive was coated on the polyurethane film using a 500 μm I-shaped applicator, allowed to stand at room temperature for 20 minutes, allowed to stand at 80°C for 70 minutes, heated to 110°C and allowed to stand for 80 minutes, cooled to room temperature, and a polyurethane protective tape for aviation was obtained.

[0026] Example 2: A method for preparing a polyurethane protective tape for aviation, comprising the following steps: (1) Add 4,4'-dichlorobenzophenone and diethyl benzylphosphonate in a molar ratio of 1:1 to tetrahydrofuran (15 times the mass of 4,4'-dichlorobenzophenone), stir at 1°C, 250 r / min for 9 minutes, add potassium tert-butoxide (0.04 times the mass of 4,4'-dichlorobenzophenone), continue stirring for 7 minutes, heat to 25°C, continue stirring for 2.5 hours, remove tetrahydrofuran by vacuum rotary evaporation, add equal volumes of deionized water and ethyl acetate, mix well, let stand and separate, take the organic phase, dry it at 55°C under vacuum conditions, and Dry for 9 hours to obtain dichlorotriphenylethylene; mix dichlorotriphenylethylene and toluene at a mass ratio of 1:6.5 to prepare a dichlorotriphenylethylene solution; mix ethylene glycol (1.15 times the molar amount of dichlorotriphenylethylene), triethylamine, and toluene at a mass ratio of 1:0.05:9 to obtain the dichlorotriphenylethylene solution; add the dichlorotriphenylethylene solution dropwise at a constant speed over 20 minutes at 55°C and 250 r / min stirring; after the addition is complete, heat to 65°C, continue stirring and reacting for 3.5 hours, and dry at 55°C under vacuum for 9 hours to obtain an ultraviolet absorbing monomer; (2) Polyester diol, UV absorbing monomer, 3-(4-pyridyl)pentane-1,5-diol, 1,4-butanediol and N,N-dimethylformamide were mixed in a mass ratio of 1:0.7:0.55:0.35:13, stirred at 50°C and 250r / min for 17min, and 3.1 times the mass of polyester diol of isophorone diisocyanate and 0.04 times the mass of polyester diol of dibutyltin dilaurate were added, and the reaction was continued with stirring for 25min. The temperature was raised to 99°C, and the reaction was continued with stirring for 4.5h. The isophorone diisocyanate was added. The polyurethane was mixed with anhydrous ethanol 1.1 times the mass of the ester, and the mixture was stirred for 6 minutes. The mixture was dried at 75°C for 11 hours under vacuum conditions to obtain polyurethane; polyurethane and N,N-dimethylformamide were mixed at a mass ratio of 1:7, stirred at 45°C and 150r / min for 9 minutes, 2-bromoethyl acrylate 1.3 times the mass of the polyurethane was added, the temperature was raised to 60°C, and the stirring was continued for 2.5 hours. N,N-dimethylformamide was removed by vacuum rotary evaporation, and the mixture was washed with anhydrous ethanol 4 times. The mixture was dried at 65°C for 11 hours under vacuum conditions to obtain modified polyurethane; (3) Vinyl triethoxysilane and anhydrous ethanol were mixed at a mass ratio of 1:7.5 to prepare a surface treatment liquid; magnesium hydroxide and deionized water were mixed at a mass ratio of 1:21 to prepare a surface treatment liquid; the mixture was ultrasonically dispersed for 55 minutes, the temperature was raised to 75 ° C, and the surface treatment liquid with a mass of 11 times that of magnesium hydroxide was added dropwise at a constant speed within 15 minutes under stirring conditions of 350 r / min. After the addition was completed, the mixture was stirred for 3.5 hours, filtered, washed with anhydrous ethanol for 4 times, and dried at 65 ° C for 7.5 hours under vacuum conditions to prepare pretreated magnesium hydroxide; the pretreated magnesium hydroxide, 3-epoxypropoxy-1,1,3,3-tetramethyldisiloxane, toluene were mixed. The mixture was mixed evenly at a mass ratio of 1:3.5:20, 0.06 times the mass of the pretreated magnesium hydroxide of chloroplatinic acid was added, the mixture was stirred at 75°C and 350r / min for 3.5h, filtered, washed with anhydrous ethanol 4 times, and dried at 65°C under vacuum for 8.5h to obtain pre-modified magnesium hydroxide; the pre-modified magnesium hydroxide and tetrahydrofuran were mixed evenly at a mass ratio of 1:20, 9 times the mass of the pre-modified magnesium hydroxide of 20% ammonia aqueous solution was added, the mixture was stirred and refluxed at 62°C and 250r / min for 4.5h, filtered, washed with deionized water 4 times, and dried at 55°C under vacuum for 9h to obtain modified magnesium hydroxide; (4) The modified polyurethane and modified magnesium hydroxide were mixed evenly in a mass ratio of 1:0.055, placed in an internal mixer, stirred at 185°C and 250 r / min for 17 minutes, placed in a calender for calendering, and the temperature of the calender was set to 181°C and the pressure was set to 31 MPa. After calendering, the film was allowed to stand at 118°C for 2.5 hours, cooled to room temperature, and a polyurethane film was obtained; polyacrylate emulsion, aluminum acetylacetonate, and acetone were mixed evenly in a mass ratio of 1:0.05:1.15, degassed in a vacuum degassing machine at 1100 r / min for 1.5 minutes to obtain a polyacrylate adhesive; the polyacrylate adhesive was coated on the polyurethane film using a 500 μm I-shaped applicator, allowed to stand at room temperature for 25 minutes, allowed to stand at 85°C for 65 minutes, heated to 115°C and allowed to stand for 75 minutes, cooled to room temperature, and a polyurethane protective tape for aviation was obtained.

[0027] Example 3: A method for preparing a polyurethane protective tape for aviation, comprising the following steps: (1) Add 4,4'-dichlorobenzophenone and diethyl benzylphosphonate in a molar ratio of 1:1 to tetrahydrofuran (16 times the mass of 4,4'-dichlorobenzophenone), stir at 2°C, 300 r / min for 8 minutes, add potassium tert-butoxide (0.05 times the mass of 4,4'-dichlorobenzophenone), continue stirring for 6 minutes, heat to 26°C, continue stirring for 2 hours, remove tetrahydrofuran by vacuum rotary evaporation, add equal volumes of deionized water and ethyl acetate, mix well, let stand and separate, take the organic phase, and heat at 60°C under vacuum. Dry for 8 hours to obtain dichlorotriphenylethylene; mix dichlorotriphenylethylene and toluene at a mass ratio of 1:7 to prepare a dichlorotriphenylethylene solution; mix ethylene glycol (1.2 times the molar amount of dichlorotriphenylethylene), triethylamine, and toluene at a mass ratio of 1:0.06:10, and add the dichlorotriphenylethylene solution dropwise at a constant speed over 20 minutes at 60°C and 300 r / min stirring conditions. After the addition is complete, heat to 66°C, continue stirring and react for 3 hours, and dry at 60°C under vacuum conditions for 8 hours to obtain a UV absorbing monomer; (2) Polyester diol, UV absorbing monomer, 3-(4-pyridyl)pentane-1,5-diol, 1,4-butanediol and N,N-dimethylformamide were mixed in a mass ratio of 1:0.8:0.6:0.4:14, stirred at 52°C and 300 r / min for 16 min, and 3.2 times the mass of polyester diol of isophorone diisocyanate and 0.05 times the mass of polyester diol of dibutyltin dilaurate were added, and the reaction was continued with stirring for 24 min. The temperature was raised to 100°C, and the reaction was continued with stirring for 4 h. The isophorone diisocyanate was added. The polyurethane was mixed with anhydrous ethanol 1.2 times the mass of the ester, and the mixture was stirred for 5 minutes. The mixture was dried at 80°C for 10 hours under vacuum conditions to obtain polyurethane; polyurethane and N,N-dimethylformamide were mixed at a mass ratio of 1:8, stirred at 50°C and 200r / min for 8 minutes, 2-bromoethyl acrylate 1.4 times the mass of the polyurethane was added, the mixture was heated to 62°C, and the mixture was stirred for 2 hours. N,N-dimethylformamide was removed by vacuum rotary evaporation, and the mixture was washed with anhydrous ethanol 5 times. The mixture was dried at 70°C for 10 hours under vacuum conditions to obtain modified polyurethane; (3) Vinyl triethoxysilane and anhydrous ethanol were mixed at a mass ratio of 1:8 to prepare a surface treatment liquid; magnesium hydroxide and deionized water were mixed at a mass ratio of 1:22 to prepare a surface treatment liquid; the mixture was ultrasonically dispersed for 60 minutes, the temperature was raised to 80 ° C, and the surface treatment liquid with a mass of 12 times that of magnesium hydroxide was added dropwise at a constant speed within 15 minutes under stirring conditions of 400 r / min. After the addition was completed, the mixture was stirred for 3 hours, filtered, washed with anhydrous ethanol for 5 times, and dried at 70 ° C for 7 hours under vacuum conditions to prepare pretreated magnesium hydroxide; the pretreated magnesium hydroxide, 3-glycidoxy-1,1,3,3-tetramethyldisiloxane, methyl Benzene was mixed evenly in a mass ratio of 1:4:22, chloroplatinic acid with a mass fraction of 0.07 times that of the pretreated magnesium hydroxide was added, and the mixture was stirred at 80°C and 400r / min for 3h, filtered, washed with anhydrous ethanol 5 times, and dried at 70°C for 8h under vacuum conditions to obtain pre-modified magnesium hydroxide; pre-modified magnesium hydroxide and tetrahydrofuran were mixed evenly in a mass ratio of 1:21, and a 22% ammonia aqueous solution with a mass fraction of 10 times that of the pre-modified magnesium hydroxide was added, and the mixture was stirred and refluxed at 64°C and 300r / min for 4h, filtered, washed with deionized water 5 times, and dried at 60°C for 8h under vacuum conditions to obtain modified magnesium hydroxide; (4) The modified polyurethane and modified magnesium hydroxide were mixed evenly in a mass ratio of 1:0.06, placed in an internal mixer, stirred at 190°C and 300 r / min for 16 minutes, placed in a calender for calendering, and the temperature of the calender was set to 182°C and the pressure was set to 32 MPa. After calendering, the film was allowed to stand at 120°C for 2 hours, cooled to room temperature, and a polyurethane film was obtained; polyacrylate emulsion, aluminum acetylacetonate, and acetone were mixed evenly in a mass ratio of 1:0.06:1.2, degassed in a vacuum degassing machine at 1200 r / min for 1 minute to obtain a polyacrylate adhesive; the polyacrylate adhesive was coated on the polyurethane film using a 500-micron I-shaped applicator, allowed to stand at room temperature for 30 minutes, allowed to stand at 90°C for 60 minutes, heated to 120°C and allowed to stand for 70 minutes, cooled to room temperature, and a polyurethane protective tape for aviation was obtained.

[0028] Comparative Example 1: The preparation method of the aviation polyurethane protective tape of Comparative Example 1 differs from that of Example 2 in that step (1) is not performed, and step (2) is modified as follows: polyester diol, 1,6-hexanediol, 3-(4-pyridyl)pentane-1,5-diol, 1,4-butanediol, and N,N-dimethylformamide are uniformly mixed in a mass ratio of 1:0.7:0.55:0.35:13, stirred at 50°C and 250r / min for 17min, isophorone diisocyanate (3.1 times the mass of polyester diol) and dibutyltin dilaurate (0.04 times the mass of polyester diol) are added, the reaction is continued with stirring for 25min, and the temperature is raised to 4000r / min. The mixture was stirred at 99°C for 4.5 hours, and anhydrous ethanol (1.1 times the mass of isophorone diisocyanate) was added and mixed evenly. The mixture was stirred for 6 minutes and dried at 75°C under vacuum for 11 hours to produce a polyurethane. Polyurethane and N,N-dimethylformamide were mixed evenly in a mass ratio of 1:7, stirred at 45°C at 150 rpm for 9 minutes, and 2-bromoethyl acrylate (1.3 times the mass of the polyurethane) was added. The mixture was heated to 60°C and stirred for 2.5 hours. The N,N-dimethylformamide was removed by rotary evaporation under reduced pressure, and the mixture was washed four times with anhydrous ethanol. The mixture was dried at 65°C under vacuum for 11 hours to produce a modified polyurethane. The remaining steps were the same as in Example 2.

[0029] Comparative Example 2: The preparation method of the aviation polyurethane protective tape of Comparative Example 2 differs from that of Example 2 in that step (2) is different. Step (2) is modified as follows: polyester diol, ultraviolet absorbing monomer, 3-(4-pyridyl)pentane-1,5-diol, 1,4-butanediol, and N,N-dimethylformamide are mixed uniformly in a mass ratio of 1:0.7:0.55:0.35:13, stirred at 50°C and 250 r / min for 17 min, isophorone diisocyanate (3.1 times the mass of polyester diol) and dibutyltin dilaurate (0.04 times the mass of polyester diol) are added, and the mixture is stirred for 25 min. The mixture is heated to 99°C and stirred for 4.5 h. Anhydrous ethanol (1.1 times the mass of isophorone diisocyanate) is added and the mixture is mixed uniformly. The mixture is stirred for 6 min. The mixture is dried at 75°C under vacuum for 11 h to obtain a modified polyurethane. The remaining steps are the same as those of Example 2.

[0030] Comparative Example 3: The preparation method of the aviation polyurethane protective tape of Comparative Example 3 differs from that of Example 2 only in step (3). Step (3) is modified as follows: vinyl triethoxysilane and anhydrous ethanol are mixed uniformly in a mass ratio of 1:7.5 to prepare a surface treatment liquid; magnesium hydroxide and deionized water are mixed uniformly in a mass ratio of 1:21, ultrasonically dispersed for 55 minutes, heated to 75°C, and stirred at 350 r / min. The surface treatment liquid with a mass of 11 times that of the magnesium hydroxide is uniformly added dropwise within 15 minutes. After the addition is completed, stirring is continued. The reaction was continued for 3.5 hours, filtered, washed with anhydrous ethanol four times, and dried at 65°C under vacuum for 7.5 hours to obtain pretreated magnesium hydroxide. The pretreated magnesium hydroxide, 3-glycidoxy-1,1,3,3-tetramethyldisiloxane, and toluene were mixed uniformly in a mass ratio of 1:3.5:20, 0.06 times the mass of the pretreated magnesium hydroxide was added with chloroplatinic acid, and the mixture was stirred at 75°C and 350 r / min for 3.5 hours. The mixture was filtered, washed with anhydrous ethanol four times, and dried at 65°C under vacuum for 8.5 hours to obtain modified magnesium hydroxide. The remaining steps were the same as in Example 2.

[0031] Comparative Example 4: The preparation method of the aviation polyurethane protective tape of Comparative Example 4 is different from that of Example 2 in that step (3) is not performed, and step (4) is modified as follows: the modified polyurethane and magnesium hydroxide are mixed uniformly in a mass ratio of 1:0.055, placed in an internal mixer, stirred at 185°C and 250r / min for 17min, placed in a calender for calendering, and the temperature of the calender is set to 181°C and the pressure is set to 31MPa. After calendering into a film, it is allowed to stand at 118°C for 2.5h, cooled to room temperature, and prepared. A polyurethane film was obtained; polyacrylate emulsion, aluminum acetylacetonate, and acetone were uniformly mixed in a mass ratio of 1:0.05:1.15, and deaerated in a vacuum degassing machine at 1100 rpm for 1.5 minutes to obtain a polyacrylate adhesive solution; the polyacrylate adhesive solution was coated on the polyurethane film using a 500-micron I-shaped applicator, allowed to air at room temperature for 25 minutes, allowed to stand at 85°C for 65 minutes, heated to 115°C, allowed to stand for 75 minutes, and cooled to room temperature to obtain an aviation polyurethane protective tape. The remaining steps were the same as in Example 2.

[0032] Comparative Example 5: The preparation method of the aviation polyurethane protective tape of Comparative Example 5 differs from that of Example 2 in that step (3) is not performed, and step (4) is modified as follows: the modified polyurethane is placed in an internal mixer, stirred at 185°C and 250 r / min for 17 min, placed in a calender for calendering, the temperature of the calender is set to 181°C, the pressure is set to 31 MPa, and after calendering into a film, it is allowed to stand at 118°C for 2.5 h, cooled to room temperature, and a polyurethane film is prepared; polyacrylate emulsion, aluminum acetylacetonate, and acetone are uniformly mixed in a mass ratio of 1:0.05:1.15, and degassed in a vacuum degassing machine at 1100 r / min for 1.5 min to prepare a polyacrylate adhesive solution; the polyacrylate adhesive solution is coated on the polyurethane film using a 500-micron I-shaped applicator, allowed to stand at room temperature for 25 min, allowed to stand at 85°C for 65 min, heated to 115°C, allowed to stand for 75 min, and cooled to room temperature to prepare an aviation polyurethane protective tape.

[0033] Test Example 1 Basic performance test: Test Method: The hardness of Examples 1 to 3 was tested according to ASTM D2240; the 180° peel strength of Examples 1 to 3 was tested according to GB / T 2792-2014. The results are shown in Table 1.

[0034] Table 1

[0035] From the comparison of the experimental data of Examples 1 to 3 in Table 1, it can be found that the aviation polyurethane protective tape prepared by the present invention has good hardness and peel strength.

[0036] Test Example 2 Anti-aging and self-repair performance testing Test method: The examples and comparative examples were prepared into standard specimens according to ASTM D 882-2018, and the tensile strength M of the standard specimens was tested using a WDW-20 electronic tensile machine from Shanghai Sonton Instrument Manufacturing Co., Ltd. at a tensile speed of 500 mm / min. The standard sample was placed in a xenon lamp aging test chamber for UV aging test with a radiation intensity of 0.51W / m 2 (340nm), temperature is 25℃, aging time is 18 days, test its tensile strength N, calculate the performance degradation rate of the standard specimen before and after UV aging, performance degradation rate = (MN) / M×100%; A standard specimen was cut with an 18 mm long cut down the middle. The specimen was then heated at 125°C for 2 hours and allowed to stand at room temperature for 10 hours to obtain a repaired specimen. The tensile strength Q of the repaired specimen was measured, and the self-repair rate of the embodiment and comparative example was calculated as: self-repair rate = Q / M × 100%. The results are shown in Table 2.

[0037] Table 2

[0038] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 5 in Table 2, it can be found that the aviation polyurethane protective tape prepared in the present invention has good anti-aging and self-repairing properties.

[0039] By comparison, the performance degradation rates of Examples 1 to 3 are lower than that of Comparative Example 1, indicating that dichlorotriphenylethylene is prepared by reacting 4,4'-dichlorobenzophenone and diethyl benzylphosphonate; and that dichlorotriphenylethylene is prepared by reacting ethylene glycol to form an ultraviolet absorbing monomer. The hydroxyl groups introduced at both ends of the ultraviolet absorbing monomer can participate in the polymerization reaction of polyurethane, thereby introducing a triphenylethylene structure into the main chain of the polyurethane molecule. The triphenylethylene structure can undergo a photocyclization reaction under the action of ultraviolet light and a ring-opening reaction under the action of visible light. This reversible cyclization reaction can absorb ultraviolet light and release the ultraviolet light energy in a harmless form, thereby giving the aviation polyurethane protective tape excellent anti-aging properties.

[0040] By comparison, the self-repair rates of Examples 1 to 3 are greater than that of Comparative Example 2, indicating that the polyester diol, the ultraviolet absorbing monomer, 3-(4-pyridyl)pentane-1,5-diol, 1,4-butanediol and isophorone diisocyanate are polymerized to prepare polyurethane, and a pyridine structure is introduced into the side chain of the polyurethane molecule; the pyridine structure introduced into the side chain of the polyurethane molecule is reacted with 2-bromoethyl acrylate to prepare a modified polyurethane; an acrylate structure is introduced into the side chain of the modified polyurethane molecule; the acrylate structure can undergo a thermally reversible Aza-Michael addition reaction with the β-hydroxyamine structure introduced into the modified magnesium hydroxide to form a dynamic covalent β-hydroxyester crosslink. This dynamic covalent β-hydroxyester crosslink structure will break at high temperature and recombine when the temperature is lowered, thereby giving the aviation polyurethane protective tape a thermally responsive self-repairing property.

[0041] By comparison, the self-repair rates of Examples 1 to 3 are greater than those of Comparative Examples 3 to 5, indicating that pretreated magnesium hydroxide is prepared by reacting magnesium hydroxide and vinyltriethoxysilane, and a carbon-carbon double bond is introduced on the pretreated magnesium hydroxide; the carbon-carbon double bond on the pretreated magnesium hydroxide is subjected to a hydrosilylation reaction with the Si-H bond on 3-glycidoxy-1,1,3,3-tetramethyldisiloxane to prepare pre-modified magnesium hydroxide, an epoxy group is introduced on the pre-modified magnesium hydroxide, and the epoxy group on the pre-modified magnesium hydroxide is subjected to a ring-opening reaction with ammonia water to prepare modified magnesium hydroxide, and a β-hydroxyamine structure is generated on the modified magnesium hydroxide; the β-hydroxyamine structure generated on the modified magnesium hydroxide can undergo a thermally reversible Aza-Michael addition reaction with the acrylate structure introduced on the side chain of the modified polyurethane molecule to form a dynamic covalent β-hydroxyester crosslink. This dynamic covalent β-hydroxyester crosslink structure will break at high temperature and recombine when the temperature is lowered, thereby giving the aviation polyurethane protective tape a thermally responsive self-repairing property.

[0042] Test Example 3 Flame retardant performance test Test method: The examples and comparative examples were prepared into standard specimens according to GB / T 2406, and the limiting oxygen index of the standard specimens was tested. The results are shown in Table 3.

[0043] Table 3

[0044] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 5 in Table 3, it can be found that the aviation polyurethane protective tape prepared by the present invention has good flame retardant properties.

[0045] By comparison, the limiting oxygen index of Examples 1 to 3 is greater than that of Comparative Examples 4 to 5, indicating that pretreated magnesium hydroxide is prepared by reacting magnesium hydroxide and vinyltriethoxysilane, and a carbon-carbon double bond is introduced into the pretreated magnesium hydroxide; the carbon-carbon double bond on the pretreated magnesium hydroxide is subjected to a hydrosilylation reaction with the Si-H bond on 3-glycidoxy-1,1,3,3-tetramethyldisiloxane to prepare pre-modified magnesium hydroxide, and Si-O bonds are introduced into the pre-modified magnesium hydroxide. The introduction of Si-O bonds can improve the flame retardant properties of the polyurethane protective tape for aviation; magnesium hydroxide is an inorganic flame retardant material that can release water vapor during combustion, promote carbonization, and decompose to absorb heat to further improve the flame retardant properties of the polyurethane protective tape for aviation.

[0046] Test Example 4 Antibacterial performance testing Test method: Use a puncher to take a 6 mm diameter circular slice from the embodiment and the comparative example; use Escherichia coli as the experimental bacteria, activate the experimental bacteria at 37 ° C for 24 hours, and prepare a concentration of 1×10 7cfu / mL bacterial suspension; 0.2 ml of the bacterial suspension was evenly coated on the surface of beef extract peptone agar medium. A circular thin slice was then placed upside down on the surface of the medium and incubated in a constant temperature incubator at 37°C for 24 hours. The diameter of the inhibition zone was measured. The results are shown in Table 4.

[0047] Table 4

[0048] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 5 in Table 4, it can be found that the aviation polyurethane protective tape prepared by the present invention has good antibacterial properties.

[0049] By comparison, the diameters of the inhibition zones of Examples 1 to 3 are larger than that of Comparative Example 2, indicating that polyester diol, ultraviolet absorbing monomer, 3-(4-pyridyl)pentane-1,5-diol, 1,4-butanediol and isophorone diisocyanate are polymerized to prepare polyurethane, and a pyridine structure is introduced into the side chain of the polyurethane molecule; the pyridine structure introduced into the side chain of the polyurethane molecule is reacted with 2-bromoethyl acrylate to prepare a modified polyurethane; a pyridinium salt is generated on the side chain of the modified polyurethane molecule; and the pyridinium salt can improve the antibacterial properties of the polyurethane protective tape for aviation.

[0050] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A polyurethane protective tape for aviation, characterized in that: The aviation polyurethane protective tape comprises the following steps: preparing polyurethane by polymerizing polyester diol, ultraviolet absorbing monomer, 3-(4-pyridyl)pentane-1,5-diol, 1,4-butanediol and isophorone diisocyanate; preparing modified polyurethane by reacting polyurethane with 2-bromoethyl acrylate; preparing modified magnesium hydroxide by reacting pre-modified magnesium hydroxide with ammonia water; mixing the modified polyurethane and modified magnesium hydroxide and then performing compression molding to prepare a polyurethane film; and coating the polyurethane film with a polyacrylate adhesive and drying the resulting film. The ultraviolet absorption monomer is prepared by reacting 4,4'-dichlorobenzophenone with diethyl benzylphosphonate and ethylene glycol in sequence; The pre-modified magnesium hydroxide is prepared by reacting pre-treated magnesium hydroxide and 3-glycidoxy-1,1,3,3-tetramethyldisiloxane; The pretreated magnesium hydroxide is prepared by reacting magnesium hydroxide and vinyltriethoxysilane; The polyacrylate adhesive is prepared by mixing polyacrylate emulsion, aluminum acetylacetonate and acetone.

2. A method for preparing a polyurethane protective tape for aviation, characterized in that: The preparation method of the polyurethane protective tape for aviation includes the following preparation steps: (1) Polyurethane and N,N-dimethylformamide were mixed uniformly in a mass ratio of 1:(6-8), stirred at 40-50°C and 100-200 r / min for 8-10 min, 2-bromoethyl acrylate (1.2-1.4 times the mass of polyurethane) was added, the temperature was raised to 58-62°C, and the stirring reaction was continued for 2-3 h. N,N-dimethylformamide was removed by vacuum rotary evaporation, and the mixture was washed with anhydrous ethanol for 3-5 times. The mixture was dried at 60-70°C under vacuum conditions for 10-12 h to obtain modified polyurethane. (2) Pre-modified magnesium hydroxide and tetrahydrofuran were mixed uniformly in a mass ratio of 1:(19~21), and an aqueous ammonia solution with a mass fraction of 18%~22% of 8~10 times the mass of the pre-modified magnesium hydroxide was added, and the mixture was stirred and refluxed at 60~64°C and 200~300r / min for 4~5h, filtered, washed with deionized water for 3~5 times, and dried at 50~60°C under vacuum conditions for 8~10h to obtain modified magnesium hydroxide; (3) The modified polyurethane and modified magnesium hydroxide were mixed evenly in a mass ratio of 1:(0.05~0.06), placed in an internal mixer, stirred at 180~190℃, 200~300r / min for 16~18min, placed in a calender for calendering, and after calendering into a film, allowed to stand at 116~120℃ for 2~3h, cooled to room temperature, and a polyurethane film was obtained; a 500μm I-shaped coater was used to coat the polyurethane glue on the polyurethane film, allowed to stand at room temperature for 20~30min, allowed to stand at 80~90℃ for 60~70min, heated to 110~120℃, allowed to stand for 70~80min, and cooled to room temperature to obtain a polyurethane protective tape for aviation.

3. The method for preparing a polyurethane protective tape for aviation according to claim 2, characterized in that: The preparation method of the polyurethane in step (1) is as follows: polyester diol, ultraviolet absorption monomer, 3-(4-pyridyl)pentane-1,5-diol, 1,4-butanediol, N,N-dimethylformamide are mixed uniformly in a mass ratio of 1:(0.6~0.8):(0.5~0.6):(0.3~0.4):(12~14), stirred at 48~52°C and 200~300r / min for 16~18min, and polyester diol is added. Add 3 to 3.2 times the mass of isophorone diisocyanate and 0.03 to 0.05 times the mass of polyester diol to dibutyltin dilaurate, continue stirring and reacting for 24 to 26 minutes, raise the temperature to 98 to 100 ° C, continue stirring and reacting for 4 to 5 hours, add 1 to 1.2 times the mass of isophorone diisocyanate to anhydrous ethanol, mix evenly, continue stirring for 5 to 7 minutes, and dry at 70 to 80 ° C under vacuum conditions for 10 to 12 hours to obtain polyurethane.

4. The method for preparing a polyurethane protective tape for aviation according to claim 3, characterized in that: The preparation method of the ultraviolet absorption monomer comprises the following steps: uniformly mixing dichlorotriphenylethylene and toluene at a mass ratio of 1:(6-7) to prepare a dichlorotriphenylethylene solution; uniformly mixing ethylene glycol (1.1-1.2 times the molar amount of dichlorotriphenylethylene), triethylamine, and toluene at a mass ratio of 1:(0.04-0.06):(8-10); uniformly adding the dichlorotriphenylethylene solution dropwise at a temperature of 50-60° C. and a stirring speed of 200-300 r / min over 20 minutes; raising the temperature to 64-66° C. after the addition is complete, continuing the stirring reaction for 3-4 hours, and drying at 50-60° C. under vacuum conditions for 8-10 hours to prepare the ultraviolet absorption monomer.

5. The method for preparing a polyurethane protective tape for aviation according to claim 4, characterized in that: The preparation method of the dichlorotriphenylethylene comprises the following steps: adding 4,4'-dichlorobenzophenone and diethyl benzylphosphonate in a molar ratio of 1:1 to tetrahydrofuran (14-16 times the mass of 4,4'-dichlorobenzophenone), stirring at 0-2°C and 200-300 r / min for 8-10 minutes, adding potassium tert-butoxide (0.03-0.05 times the mass of 4,4'-dichlorobenzophenone), continuing stirring for 6-8 minutes, heating to 24-26°C, continuing stirring for 2-3 hours, removing tetrahydrofuran by vacuum rotary evaporation, adding equal volumes of deionized water and ethyl acetate, mixing evenly, allowing to stand and separate, taking the organic phase, and drying it at 50-60°C under vacuum conditions for 8-10 hours to obtain the dichlorotriphenylethylene.

6. The method for preparing a polyurethane protective tape for aviation according to claim 2, characterized in that: The preparation method of the pre-modified magnesium hydroxide in step (2) is as follows: pre-treated magnesium hydroxide, 3-glycidoxy-1,1,3,3-tetramethyldisiloxane and toluene are mixed uniformly in a mass ratio of 1:(3~4):(18~22), 0.05~0.07 times the mass of the pre-treated magnesium hydroxide is added with chloroplatinic acid, the mixture is stirred at 70~80°C and 300~400r / min for 3~4h, filtered, washed with anhydrous ethanol 3~5 times, and dried at 60~70°C under vacuum conditions for 8~9h to obtain pre-modified magnesium hydroxide.

7. The method for preparing a polyurethane protective tape for aviation according to claim 6, characterized in that: The preparation method of the pretreated magnesium hydroxide comprises the following steps: uniformly mixing vinyltriethoxysilane and anhydrous ethanol at a mass ratio of 1:(7-8) to prepare a surface treatment liquid; uniformly mixing magnesium hydroxide and deionized water at a mass ratio of 1:(20-22), ultrasonically dispersing for 50-60 minutes, heating to 70-80°C, and dropwise adding the surface treatment liquid in an amount 10-12 times the mass of the magnesium hydroxide at a constant speed within 15 minutes under stirring conditions of 300-400 r / min; continuing stirring and reacting for 3-4 hours after the dropwise addition is completed, filtering, washing with anhydrous ethanol for 3-5 times, and drying at 60-70°C under vacuum conditions for 7-8 hours to prepare the pretreated magnesium hydroxide.

8. The method for preparing a polyurethane protective tape for aviation according to claim 7, characterized in that: The particle size of the magnesium hydroxide is 1000 mesh.

9. The method for preparing a polyurethane protective tape for aviation according to claim 2, characterized in that: The process parameters of the calendering molding in step (3) are as follows: the temperature of the calender is set to 180~182℃, and the pressure is set to 30~32MPa.

10. The method for preparing a polyurethane protective tape for aviation according to claim 2, characterized in that: The preparation method of the polyacrylate adhesive in step (3) is as follows: polyacrylate emulsion, aluminum acetylacetonate and acetone are uniformly mixed in a mass ratio of 1:(0.04-0.06):(1.1-1.2), and deaerated in a vacuum degassing machine at 1000-1200 r / min for 1-2 minutes to obtain the polyacrylate adhesive.

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