High-wear-resistance anti-aging polyurethane vehicle film and preparation method thereof

Abstract

The invention is suitable for the technical field of vehicle film production, and provides a high-wear-resistance anti-aging polyurethane vehicle film and a preparation method thereof.The vehicle film is prepared from a polyurethane matrix, modified composite filler, magnetic microcapsules and an anti-aging agent, the modified composite filler comprises dynamic bond grafted polyrotaxane, modified graphene oxide and photoresponsive hyperbranched polysiloxane, and the magnetic microcapsules are directionally distributed in a near-surface area of the vehicle film under the assistance of a magnetic field. According to the high-wear-resistance anti-aging polyurethane vehicle film provided by the invention, the coordination of dynamic wear resistance and light-operated self-repairing is realized through a polyrotaxane / modified graphene oxide / light-responsive hyperbranched polysiloxane ternary system, the anti-aging agent is a rare earth MOF loaded dopamine derivative, and the anti-aging function and the service life diagnosis function are integrated; the microcapsule containing the polyurethane prepolymer is compounded with a dynamic network of photoresponse hyperbranched polysiloxane and polyrotaxane to construct a dual self-repairing mechanism, and the anti-aging time can be prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle film production, and particularly relates to a highly wear-resistant and anti-aging polyurethane vehicle film and a preparation method thereof. Background Art

[0002] The following technical defects exist in traditional polyurethane vehicle films during long-term use: Insufficient wear resistance: Conventional fillers (such as nano-SiO2) are unevenly dispersed, resulting in low surface hardness and easy generation of scratches; Poor anti-aging performance: When ultraviolet absorbers (such as benzotriazoles) are compounded with hindered amine light stabilizers (HALS), they are prone to migration and failure, and the yellowing index ΔYI > 5 after 2000 hours of QUV aging.

[0003] Therefore, a highly wear-resistant and anti-aging polyurethane vehicle film and a preparation method thereof are needed. Summary of the Invention

[0004] The present invention provides a highly wear-resistant and anti-aging polyurethane vehicle film, aiming to solve the problems of insufficient wear resistance and poor anti-aging performance of traditional polyurethane vehicle films.

[0005] The present invention is realized as follows. A highly wear-resistant and anti-aging polyurethane vehicle film comprises the following raw materials in parts by weight: 60 - 70 parts of a polyurethane matrix, 10 - 20 parts of a modified composite filler, 5 - 12 parts of magnetic microcapsules, and 1 - 5 parts of an anti-aging agent. The modified composite filler comprises dynamically grafted polyrotaxane, modified graphene oxide, and photo-responsive hyperbranched polysiloxane. The magnetic microcapsules are distributed in the near-surface area of the vehicle film (10 - 20 μm away from the surface) by magnetic field assistance, and the anti-aging agent is a rare earth MOF loaded with dopamine derivatives.

[0006] Preferably, it comprises the following raw materials in parts by weight: 62 - 68 parts of a polyurethane matrix, 13 - 17 parts of a modified composite filler, 7 - 10 parts of magnetic microcapsules, and 2 - 4 parts of an anti-aging agent.

[0007] Preferably, it comprises the following raw materials in parts by weight: 65 parts of a polyurethane matrix, 15 parts of a modified composite filler, 8.5 parts of magnetic microcapsules, and 3 parts of an anti-aging agent.

[0008] Preferably, the mass ratio of dynamically grafted polyrotaxane, modified graphene oxide, and photo-responsive hyperbranched polysiloxane in the modified composite filler is 2 - 3:1 - 2:1.

[0009] Preferably, the preparation method of the dynamic covalently grafted polyrotaxane is as follows: by weight, dissolve 8-12 parts of α-cyclodextrin in 100-120 parts of deionized water, and stir at 65-75 °C until completely dissolved; slowly dropwise add a solution prepared by mixing 4-6 parts of polyethylene glycol with 100-120 parts of deionized water (pre-dissolved at 60 °C), and control the dropping rate at 1 mL / min; after the dropping is completed, raise the temperature to 75-85 °C and carry out a constant-temperature reaction for 3-5 h; cool the reaction solution to room temperature, filter, wash with acetone three times, and vacuum dry to obtain a white filamentous polyrotaxane matrix; disperse the polyrotaxane matrix in 100-120 parts of anhydrous toluene, add 5 parts of isocyanatopropyltriethoxysilane and 0.1-0.3 parts of dibutyltin dilaurate under nitrogen protection, raise the temperature to 90 °C, and react for 2-4 h; after the reaction is completed, centrifuge to collect the product, wash with toluene three times, and vacuum dry at 60-70 °C to obtain the dynamic covalently grafted polyrotaxane.

[0010] Preferably, the preparation method of the modified graphene oxide is as follows: by weight, disperse 1-2 parts of graphene oxide in 100-120 parts of deionized water, and perform ultrasonic treatment for 1-2 h; add 5-8 parts of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and stir at 60 °C for 2-3 h; centrifuge and wash, and vacuum dry at 60 °C to obtain the modified graphene oxide.

[0011] Preferably, the preparation method of the photo-responsive hyperbranched polysiloxane is as follows: by weight, add 15-25 parts of methyltrimethoxysilane to 150-250 parts of an ethanol / water (volume ratio 4:1) mixed solvent, and stir at room temperature for 10-30 min; slowly dropwise add 3-7 parts of ammonia water, and control the reaction temperature ≤ 30 °C (assisted by an ice-water bath); after the dropping is completed, raise the temperature to 50 °C and react for 1-2 h; dialyze and purify (cut-off molecular weight 3500 Da), and freeze-dry to obtain a colorless and transparent hyperbranched polysiloxane. Disperse the hyperbranched polysiloxane in 150-200 parts of tetrahydrofuran, add 4-6 parts of triethylamine, and cool to 0 °C in an ice-water bath under nitrogen protection; slowly dropwise add a solution prepared by mixing 6-10 parts of cinnamoyl chloride with 15-20 parts of tetrahydrofuran, and control the dropping rate at 0.5 mL / min; after the dropping is completed, raise the temperature to 25-30 °C and react for 24 h; filter to remove the salt precipitate, and rotary evaporate to remove the solvent to obtain the photo-responsive hyperbranched polysiloxane.

[0012] Preferably, the preparation method of the magnetic microcapsules is as follows: by weight, disperse 4-6 parts of Fe3O4 nanoparticles (particle size 30 nm) in 50-80 parts of ethanol, add 1-3 parts of silane coupling agent KH550, and ultrasonically treat for 30-50 min, then dry at 60-70 °C for standby; mix 8-12 parts of polyurethane prepolymer with 1-3 parts of modified Fe3O4 nanoparticles, add 50-60 parts of toluene, and ultrasonically disperse for 30-50 min to form a homogeneous oil phase; dissolve 5-7 parts of polyvinyl alcohol in 200-300 parts of deionized water, and heat to 60 °C to dissolve to obtain an aqueous phase; slowly drop the oil phase into the aqueous phase, and perform high-speed shear emulsification (10000 rpm, 10-20 min) to form a W / O emulsion; add 2-4 parts of tetraethoxysilane and 1-3 parts of ammonia water (28%) to the emulsion, and stir and react at 60 °C for 2-4 h to form a SiO2 shell layer; after the reaction, add 1-2 parts of Fe3O4 nanoparticles, and continue to stir for 1-2 h to embed Fe3O4 into the shell layer; centrifuge to collect the microcapsules (3000 rpm, 10-20 min), wash with deionized water 3 times, and vacuum dry at 60 °C to obtain the magnetic microcapsules.

[0013] Preferably, the preparation method of the rare earth MOF loaded with dopamine derivatives is as follows: by weight, dissolve 1-3 parts of europium nitrate and 4-6 parts of 2-methylimidazole in 50-80 parts of methanol by ultrasonic dissolution; transfer to a high-pressure reaction kettle and react at 120 °C for 4-6 h; centrifuge to collect the blue crystals, wash with methanol 3 times, and vacuum dry at 80 °C to obtain the europium-organic framework material; disperse 1-3 parts of the europium-organic framework material in 20-60 parts of N,N-dimethylformamide, add 1-2 parts of N-acryloyl dopamine, and stir at 60 °C for 1-2 h under nitrogen protection; centrifuge to collect the solid (4000 rpm, 10 min), wash with N,N-dimethylformamide 3 times, and vacuum dry at 60 °C to obtain the rare earth MOF loaded with dopamine derivatives.

[0014] The present invention also provides a preparation method of the above-mentioned high wear-resistant and anti-aging polyurethane vehicle film, which includes the following steps: Prepare each raw material according to the ratio; Disperse the polyurethane prepolymer, modified composite filler, magnetic microcapsules and rare earth MOF loaded with dopamine derivative dispersion by core-shell structure laminar assembly through a microfluidic process; Apply a 0.5-1.5 T gradient magnetic field during the coating process to make the microcapsules migrate to the set area; Perform ultraviolet pre-curing and thermal curing in sequence to form a gradient cross-linked structure.

[0015] Compared with the prior art, the embodiments of the present application mainly have the following beneficial effects: In the raw materials of the highly wear-resistant and anti-aging polyurethane vehicle film provided by the present invention, the sliding ring structure of the polyrotaxane is crosslinked with the polyurethane hard segment through dynamic bonds, endowing the material with energy dissipation ability; the modified graphene oxide and the photo-responsive hyperbranched polysiloxane form a three-dimensional network through electrostatic interaction, dispersing local stress to the graphene sheets; under ultraviolet light irradiation, the cinnamate of the photo-responsive hyperbranched polysiloxane undergoes a [2+2] cycloaddition reaction to repair microcracks; the rare earth MOF-loaded dopamine derivative anti-aging system, where europium absorbs ultraviolet light through f-f transition and emits visible red light. When the material ages, the fluorescence intensity decreases, enabling visual monitoring of the lifespan; N-acryloyldopamine releases phenolic hydroxyl groups under ultraviolet excitation to continuously scavenge free radicals. The MOF pores restrict the migration of N-acryloyldopamine, prolonging the anti-aging aging time. The catechol group of N-acryloyldopamine forms multiple hydrogen bonds with the polyurethane soft segment, enhancing the interfacial binding force; the microcapsules containing polyurethane prepolymer are compounded with the photo-responsive hyperbranched polysiloxane and polyrotaxane dynamic network to construct a dual self-healing mechanism. The silica surface of the microcapsule shell is loaded with the rare earth MOF-loaded dopamine derivative. Under ultraviolet light irradiation, N-acryloyldopamine in the MOF pores continuously releases phenolic hydroxyl groups to scavenge free radicals; after the shell layer ruptures, the released prepolymer carries N-acryloyldopamine and further penetrates into the damaged area to assist in repair while prolonging the anti-aging aging time. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a flow chart of a preparation method for a highly wear-resistant and anti-aging polyurethane vehicle film provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above description of the drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of this application or the above drawings are used to distinguish different objects and not to describe a specific order.

[0018] Reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0019] Example 1 An embodiment of the present invention provides a highly wear-resistant and anti-aging polyurethane vehicle film, which comprises the following raw materials by weight: 60 parts of polyurethane matrix, 10 parts of modified composite filler, 5 parts of magnetic microcapsules, and 1 part of rare earth MOF-loaded dopamine derivative. The modified composite filler includes dynamically grafted polyrotaxane, modified graphene oxide, and photo-responsive hyperbranched polysiloxane, and the mass ratio of the three is 2:1:1. The preparation method of the highly wear-resistant and anti-aging polyurethane vehicle film is as follows Figure 1 shown, and it includes the following steps: Prepare each raw material according to the ratio; Disperse the polyurethane prepolymer, modified composite filler, magnetic microcapsules, and rare earth MOF-loaded dopamine derivative dispersion through a microfluidic process for core-shell structured laminar assembly; Apply a 0.5T gradient magnetic field during the coating process to make the microcapsules migrate to the set area; Perform ultraviolet pre-curing and thermal curing in sequence to form a gradient cross-linked structure.

[0020] Specifically as follows: Premixing of modified composite filler Weigh dynamically grafted polyrotaxane, bulk modified graphene oxide, and photo-responsive hyperbranched polysiloxane; add the three into a supercritical CO2 reaction kettle and disperse for 1 hour at 40°C and 10 MPa to form a homogeneous suspension.

[0021] Microfluidic core-shell structure assembly Use a three-channel microfluidic chip (channel width 500μm) and control the temperature at 25°C.

[0022] Feeding parameters: Channel 1 (core layer): mixture of polyurethane prepolymer and modified composite filler, flow rate 0.1 mL / min; Channel 2 (intermediate layer): magnetic microcapsule suspension (dispersed in xylene), flow rate 0.05 mL / min; Channel 3 (outer shell layer): rare earth MOF-loaded dopamine derivative, flow rate 0.02 mL / min.

[0023] Output structure: Form a laminar ordered structure of core (polyurethane / modified composite filler)-shell (magnetic microcapsules)-outer shell (rare earth MOF-loaded dopamine derivative anti-aging system).

[0024] Magnetic field-assisted directional distribution Coat the slurry output from the microfluidics on a PET release film, and the wet film thickness is 200μm.

[0025] Immediately apply a 0.5T gradient magnetic field (direction perpendicular to the film surface) for 5 minutes to make the microcapsules migrate to the area 10-20μm away from the surface.

[0026] Gradient curing forming UV curing: Irradiate with 365 nm ultraviolet light (intensity 50 mW / cm²) for 30 seconds to trigger the crosslinking of cinnamate of the light-responsive hyperbranched polysiloxane and the fixation of the outer shell anti-aging agent.

[0027] Thermal curing: Transfer to an oven and cure at 100 °C for 2 hours to completely react the polyurethane prepolymer to form a crosslinked network.

[0028] Surface microstructure imprinting Place the cured film in a bionic honeycomb structure mold (groove depth 30 μm).

[0029] Hot press at 120 °C and 0.5 MPa for 10 seconds to form a surface micro-scale concave-convex structure.

[0030] Spray a perfluoroalkyl ethyl acrylate solution (concentration 5%) and cure it by UV (30 seconds) to form a superhydrophobic coating (contact angle > 150°).

[0031] In this example, the preparation method of the dynamic grafted polyrotaxane is as follows: by weight, dissolve 8 parts of α-cyclodextrin in 100 parts of deionized water, and stir at 65 °C until completely dissolved; slowly dropwise add a solution prepared by mixing 4 parts of polyethylene glycol with 100 parts of deionized water (pre-dissolved at 60 °C), and control the dropping rate at 1 mL / min; after the dropping is completed, raise the temperature to 75 °C and react at a constant temperature for 3 h; cool the reaction solution to room temperature, filter, wash with acetone 3 times, and dry in vacuum to obtain a white filamentous polyrotaxane matrix; disperse the polyrotaxane matrix in 100 parts of anhydrous toluene, add 5 parts of isocyanate propyltriethoxysilane and 0.1 part of dibutyltin dilaurate under nitrogen protection, raise the temperature to 90 °C, and react for 2 h; after the reaction is completed, centrifuge to collect the product, wash with toluene 3 times, and dry in vacuum at 60 °C to obtain the dynamic grafted polyrotaxane.

[0032] Furthermore, the preparation method of the modified graphene oxide is as follows: by weight, disperse 1 part of graphene oxide in 100 parts of deionized water, and perform ultrasonic treatment for 1 h; add 5 parts of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and stir at 60 °C for 2 h; centrifuge and wash, and dry in vacuum at 60 °C to obtain the modified graphene oxide.

[0033] Further, the preparation method of the light-responsive hyperbranched polysiloxane is as follows: By weight, add 15 parts of methyltrimethoxysilane to 150 parts of ethanol / water (volume ratio 4:1) mixed solvent, and stir at room temperature for 10 min; slowly add 3 parts of ammonia water, and control the reaction temperature ≤ 30 °C (assisted by ice-water bath); after the addition is completed, raise the temperature to 50 °C and react for 1 h; dialyze and purify (cut-off molecular weight 3500 Da), freeze-dry to obtain a colorless and transparent hyperbranched polysiloxane. Disperse the hyperbranched polysiloxane in 150 parts of tetrahydrofuran, add 4 parts of triethylamine, and cool to 0 °C in an ice-water bath under nitrogen protection; slowly add a solution prepared by mixing 6 parts of cinnamoyl chloride and 15 parts of tetrahydrofuran, and control the dropping rate to 0.5 mL / min; after the addition is completed, raise the temperature to 25 °C and react for 24 h; filter to remove salt precipitates, and rotary evaporate to remove the solvent to obtain the light-responsive hyperbranched polysiloxane.

[0034] In this example, the preparation method of the magnetic microcapsules is as follows: By weight, disperse 4 parts of Fe3O4 nanoparticles (particle size 30 nm) in 50 parts of ethanol, add 1 part of silane coupling agent KH550, ultrasonically treat for 30 min, and dry at 60 °C for standby; mix 8 parts of polyurethane prepolymer with 1 part of modified Fe3O4 nanoparticles, add 50 parts of toluene, and ultrasonically disperse for 30 min to form a homogeneous oil phase; dissolve 5 parts of polyvinyl alcohol in 200 parts of deionized water, and heat to 60 °C to dissolve to obtain an aqueous phase; slowly add the oil phase to the aqueous phase, and perform high-speed shear emulsification (10000 rpm, 10 min) to form a W / O emulsion; add 2 parts of tetraethoxysilane and 1 part of ammonia water (28%) to the emulsion, and stir and react at 60 °C for 2 h to form a SiO2 shell layer; after the reaction is completed, add 1 part of Fe3O4 nanoparticles and continue to stir for 1 h to embed Fe3O4 in the shell layer; centrifuge to collect the microcapsules (3000 rpm, 10 min), wash 3 times with deionized water, and vacuum dry at 60 °C to obtain the magnetic microcapsules.

[0035] In a specific implementation, the preparation method of the rare earth MOF loaded with dopamine derivative is as follows: By weight, dissolve 1 part of europium nitrate and 4 parts of 2-methylimidazole in 50 parts of methanol by ultrasonic; transfer to a high-pressure reaction kettle and react at 120 °C for 4 h; centrifuge to collect blue crystals, wash 3 times with methanol, and vacuum dry at 80 °C to obtain the europium-organic framework material; disperse 1 part of the europium-organic framework material in 20 parts of N,N-dimethylformamide, add 1 part of N-acryloyl dopamine, and stir at 60 °C for 1 h under nitrogen protection; centrifuge to collect the solid (4000 rpm, 10 min), wash 3 times with N,N-dimethylformamide, and vacuum dry at 60 °C to obtain the rare earth MOF loaded with dopamine derivative.

[0036] Example 2 An embodiment of the present invention provides a highly wear-resistant and anti-aging polyurethane vehicle film, which is different from Embodiment 1 in that it comprises the following raw materials by weight: 62 parts of polyurethane matrix, 13 parts of modified composite filler, 7 parts of magnetic microcapsules, and 2 parts of rare earth MOF-loaded dopamine derivatives.

[0037] Embodiment 3 An embodiment of the present invention provides a highly wear-resistant and anti-aging polyurethane vehicle film, which comprises the following raw materials by weight: 65 parts of polyurethane matrix, 15 parts of modified composite filler, 8.5 parts of magnetic microcapsules, and 3 parts of rare earth MOF-loaded dopamine derivatives. The modified composite filler comprises dynamically grafted polyrotaxane, modified graphene oxide, and photo-responsive hyperbranched polysiloxane, and the mass ratio of the three is 2.5:1.5:1. The preparation method of the highly wear-resistant and anti-aging polyurethane vehicle film is as Figure 1 shown and comprises the following steps: Prepare each raw material according to the ratio; Disperse the polyurethane prepolymer, modified composite filler, magnetic microcapsules, and rare earth MOF-loaded dopamine derivative dispersion by core-shell structured laminar assembly through a microfluidic process; Apply a 1T gradient magnetic field during the coating process to make the microcapsules migrate to the set area; Perform ultraviolet pre-curing and thermal curing in sequence to form a gradient cross-linked structure.

[0038] Specifically as follows: Premixing of modified composite filler Weigh dynamically grafted polyrotaxane, bulk modified graphene oxide, and photo-responsive hyperbranched polysiloxane; add the three into a supercritical CO2 reaction kettle and disperse for 1 hour at 40°C and 10 MPa to form a homogeneous suspension.

[0039] Microfluidic core-shell structure assembly Use a three-channel microfluidic chip (channel width 500 μm) and control the temperature at 25°C.

[0040] Feeding parameters: Channel 1 (core layer): mixture of polyurethane prepolymer and modified composite filler, flow rate 0.1 mL / min; Channel 2 (intermediate layer): magnetic microcapsule suspension (dispersed in xylene), flow rate 0.05 mL / min; Channel 3 (outer shell layer): rare earth MOF-loaded dopamine derivatives, flow rate 0.02 mL / min.

[0041] Output structure: Form a laminar ordered structure of core (polyurethane / modified composite filler)-shell (magnetic microcapsules)-outer shell (rare earth MOF-loaded dopamine derivative anti-aging system).

[0042] Magnetic field assisted directional distribution The slurry output from microfluidics is coated on a PET release film, and the wet film thickness is 200 μm.

[0043] Immediately apply a 1T gradient magnetic field (direction perpendicular to the film surface) for 5 minutes to make the microcapsules migrate to the area 10 - 20 μm away from the surface.

[0044] Gradient curing and forming UV curing: Irradiate with 365 nm ultraviolet light (intensity 50 mW / cm²) for 30 seconds to trigger the crosslinking of cinnamate of the light-responsive hyperbranched polysiloxane and the fixation of the outer shell layer anti-aging agent.

[0045] Thermal curing: Transfer to an oven and cure at 100 °C for 2 hours to make the polyurethane prepolymer react completely to form a crosslinked network.

[0046] Surface microstructure imprinting Place the cured film in a bionic honeycomb structure mold (groove depth 30 μm).

[0047] Hot press at 120 °C and 0.5 MPa for 10 seconds to form a surface micron-scale concave-convex structure.

[0048] Spray a perfluoroalkyl ethyl acrylate solution (concentration 5%) and cure it by UV (30 seconds) to form a superhydrophobic coating (contact angle > 150°).

[0049] In this example, the preparation method of the dynamic covalent grafted polyrotaxane is as follows: by weight, dissolve 10 parts of α-cyclodextrin in 110 parts of deionized water, stir at 70 °C until completely dissolved; slowly dropwise add a solution prepared by mixing 5 parts of polyethylene glycol and 110 parts of deionized water (pre-dissolved at 60 °C), and control the dropping rate to 1 mL / min; after dropping, raise the temperature to 80 °C and react at a constant temperature for 3 - 5 h; cool the reaction solution to room temperature, filter, wash with acetone 3 times, and vacuum dry to obtain a white filamentous polyrotaxane matrix; disperse the polyrotaxane matrix in 110 parts of anhydrous toluene, add 5 parts of isocyanatopropyltriethoxysilane and 0.2 part of dibutyltin dilaurate under nitrogen protection, raise the temperature to 90 °C, and react for 3 h; after the reaction, centrifuge to collect the product, wash with toluene 3 times, and vacuum dry at 65 °C to obtain the dynamic covalent grafted polyrotaxane.

[0050] Furthermore, the preparation method of the modified graphene oxide is as follows: by weight, disperse 1.5 parts of graphene oxide in 110 parts of deionized water and ultrasonically treat for 1.5 h; add 6.5 parts of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, stir at 60 °C for 2.5 h; centrifuge and wash, and vacuum dry at 60 °C to obtain the modified graphene oxide.

[0051] Furthermore, the preparation method of the light-responsive hyperbranched polysiloxane is as follows: By weight, add 20 parts of methyltrimethoxysilane to 150 - 250 parts of ethanol / water (volume ratio 4:1) mixed solvent, and stir at room temperature for 20 min; slowly add 5 parts of ammonia water, and control the reaction temperature ≤ 30 °C (assisted by ice-water bath); after the addition is complete, raise the temperature to 50 °C and react for 1.5 h; dialyze and purify (cut-off molecular weight 3500 Da), and freeze-dry to obtain a colorless and transparent hyperbranched polysiloxane. Disperse the hyperbranched polysiloxane in 175 parts of tetrahydrofuran, add 5 parts of triethylamine, and cool to 0 °C in an ice-water bath under nitrogen protection; slowly add a solution prepared by mixing 8 parts of cinnamoyl chloride and 17.5 parts of tetrahydrofuran, and control the dropping rate at 0.5 mL / min; after the addition is complete, raise the temperature to 27.5 °C and react for 24 h; filter to remove salt precipitation, and rotary evaporate to remove the solvent to obtain the light-responsive hyperbranched polysiloxane.

[0052] In this example, the preparation method of the magnetic microcapsules is as follows: By weight, disperse 5 parts of Fe3O4 nanoparticles (particle size 30 nm) in 65 parts of ethanol, add 2 parts of silane coupling agent KH550, and ultrasonically treat for 40 min, and dry at 65 °C for standby; mix 10 parts of polyurethane prepolymer and 2 parts of modified Fe3O4 nanoparticles, add 55 parts of toluene, and ultrasonically disperse for 40 min to form a homogeneous oil phase; dissolve 6 parts of polyvinyl alcohol in 250 parts of deionized water and heat to 60 °C to dissolve to obtain an aqueous phase; slowly drop the oil phase into the aqueous phase and perform high-speed shear emulsification (10000 rpm, 15 min) to form a W / O emulsion; add 3 parts of tetraethoxysilane and 2 parts of ammonia water (28%) to the emulsion, and stir and react at 60 °C for 3 h to form a SiO2 shell layer; after the reaction is completed, add 1.5 parts of Fe3O4 nanoparticles and continue to stir for 1.5 h to embed Fe3O4 into the shell layer; centrifuge to collect the microcapsules (3000 rpm, 15 min), wash 3 times with deionized water, and vacuum dry at 60 °C to obtain the magnetic microcapsules.

[0053] In a specific implementation, the preparation method of the rare earth MOF loaded with dopamine derivatives is as follows: By weight, dissolve 2 parts of europium nitrate and 5 parts of 2-methylimidazole in 50 - 80 parts of methanol by ultrasonic dissolution; transfer to a high-pressure reaction kettle and react at 120 °C for 5 h; centrifuge to collect blue crystals, wash 3 times with methanol, and vacuum dry at 80 °C to obtain an europium-organic framework material; disperse 2 parts of the europium-organic framework material in 40 parts of N,N-dimethylformamide, add 1.5 parts of N-acryloyldopamine, and stir at 60 °C for 1.5 h under nitrogen protection; centrifuge to collect the solid (4000 rpm, 10 min), wash 3 times with N,N-dimethylformamide, and vacuum dry at 60 °C to obtain the rare earth MOF loaded with dopamine derivatives.

[0054] Example 4 An embodiment of the present invention provides a highly wear-resistant and anti-aging polyurethane vehicle film, which comprises the following raw materials in parts by weight: 68 parts of polyurethane matrix, 17 parts of modified composite filler, 10 parts of magnetic microcapsules, and 4 parts of rare earth MOF-loaded dopamine derivative. The modified composite filler includes dynamically grafted polyrotaxane, modified graphene oxide, and photo-responsive hyperbranched polysiloxane, and the mass ratio of the three is 3:2:1. The preparation method of the highly wear-resistant and anti-aging polyurethane vehicle film is as Figure 1 shown, and it includes the following steps: Prepare each raw material according to the ratio; Disperse the polyurethane prepolymer, modified composite filler, magnetic microcapsules, and rare earth MOF-loaded dopamine derivative dispersion into a core-shell structure by laminar flow assembly through a microfluidic process; Apply a 1.5T gradient magnetic field during the coating process to make the microcapsules migrate to the set area; Perform ultraviolet pre-curing and thermal curing in sequence to form a gradient cross-linked structure.

[0055] Specifically as follows: Premixing of modified composite filler Weigh dynamically grafted polyrotaxane, bulk modified graphene oxide, and photo-responsive hyperbranched polysiloxane; add the three into a supercritical CO2 reaction kettle and disperse for 1 hour at 40°C and 10 MPa to form a homogeneous suspension.

[0056] Microfluidic core-shell structure assembly Use a three-channel microfluidic chip (channel width 500 μm) and control the temperature at 25°C.

[0057] Feeding parameters: Channel 1 (core layer): mixture of polyurethane prepolymer and modified composite filler, flow rate 0.1 mL / min; Channel 2 (intermediate layer): magnetic microcapsule suspension (dispersed in xylene), flow rate 0.05 mL / min; Channel 3 (outer shell layer): rare earth MOF-loaded dopamine derivative, flow rate 0.02 mL / min.

[0058] Output structure: Form a laminar ordered structure of core (polyurethane / modified composite filler)-shell (magnetic microcapsules)-outer shell (rare earth MOF-loaded dopamine derivative anti-aging system).

[0059] Magnetic field-assisted directional distribution Coat the slurry output from the microfluidic device onto a PET release film, and the wet film thickness is 200 μm.

[0060] Immediately apply a 1.5T gradient magnetic field (direction perpendicular to the film surface) for 5 minutes to make the microcapsules migrate to the area 10-20 μm away from the surface.

[0061] Gradient curing forming UV curing: Irradiate with 365 nm ultraviolet light (intensity 50 mW / cm²) for 30 seconds to trigger the crosslinking of cinnamate of the light-responsive hyperbranched polysiloxane and the fixation of the outer shell anti-aging agent.

[0062] Thermal curing: Transfer to an oven and cure at 100 °C for 2 hours to make the polyurethane prepolymer react completely to form a crosslinked network.

[0063] Surface microstructure imprinting Place the cured film in a bionic honeycomb structure mold (groove depth 30 μm).

[0064] Hot press at 120 °C and 0.5 MPa for 10 seconds to form a surface micron-scale concave-convex structure.

[0065] Spray a perfluoroalkyl ethyl acrylate solution (concentration 5%) and cure it by UV (30 seconds) to form a superhydrophobic coating (contact angle > 150°).

[0066] In this example, the preparation method of the dynamic grafted polyrotaxane is as follows: By weight, dissolve 12 parts of α-cyclodextrin in 120 parts of deionized water, and stir at 75 °C until completely dissolved; slowly dropwise add a solution prepared by mixing 6 parts of polyethylene glycol and 120 parts of deionized water (pre-dissolved at 60 °C), and control the dropping rate to be 1 mL / min; after the dropping is completed, raise the temperature to 85 °C and react at a constant temperature for 5 h; cool the reaction solution to room temperature, filter, wash it with acetone 3 times, and dry it under vacuum to obtain a white filamentous polyrotaxane matrix; disperse the polyrotaxane matrix in 120 parts of anhydrous toluene, add 5 parts of isocyanate propyltriethoxysilane and 0.3 part of dibutyltin dilaurate under nitrogen protection, raise the temperature to 90 °C, and react for 4 h; after the reaction is completed, centrifuge to collect the product, wash it with toluene 3 times, and dry it under vacuum at 70 °C to obtain the dynamic grafted polyrotaxane.

[0067] Further, the preparation method of the modified graphene oxide is as follows: By weight, disperse 2 parts of graphene oxide in 120 parts of deionized water, and perform ultrasonic treatment for 2 h; add 8 parts of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and stir at 60 °C for 3 h; centrifuge and wash, and dry under vacuum at 60 °C to obtain the modified graphene oxide.

[0068] Furthermore, the preparation method of the photo-responsive hyperbranched polysiloxane is as follows: By weight, 25 parts of methyltrimethoxysilane are added to 250 parts of an ethanol / water (volume ratio 4:1) mixed solvent, and stirred at room temperature for 30 min; 7 parts of ammonia water are slowly added dropwise, and the reaction temperature is controlled ≤ 30 °C (assisted by an ice-water bath); after the dropwise addition is completed, the temperature is raised to 50 °C and reacted for 2 h; dialysis purification (cut-off molecular weight 3500 Da), freeze-drying to obtain a colorless and transparent hyperbranched polysiloxane. The hyperbranched polysiloxane is dispersed in 200 parts of tetrahydrofuran, 6 parts of triethylamine are added, and cooled to 0 °C in an ice-water bath under nitrogen protection; a solution prepared by mixing 10 parts of cinnamoyl chloride and 20 parts of tetrahydrofuran is slowly added dropwise, and the dropping rate is controlled at 0.5 mL / min; after the dropwise addition is completed, the temperature is raised to 30 °C and reacted for 24 h; the salt precipitate is removed by filtration, and the solvent is removed by rotary evaporation to obtain the photo-responsive hyperbranched polysiloxane.

[0069] In this example, the preparation method of the magnetic microcapsules is as follows: By weight, 6 parts of Fe3O4 nanoparticles (particle size 30 nm) are dispersed in 80 parts of ethanol, 3 parts of silane coupling agent KH550 are added, and ultrasonic treatment is carried out for 50 min, and dried at 70 °C for standby; 12 parts of polyurethane prepolymer and 3 parts of modified Fe3O4 nanoparticles are mixed, 60 parts of toluene are added, and ultrasonic dispersion is carried out for 50 min to form a homogeneous oil phase; 7 parts of polyvinyl alcohol are dissolved in 300 parts of deionized water, and heated to 60 °C to dissolve to obtain an aqueous phase; the oil phase is slowly added dropwise to the aqueous phase, and high-speed shear emulsification (10000 rpm, 20 min) is carried out to form a W / O emulsion; 4 parts of tetraethoxysilane and 3 parts of ammonia water (28%) are added to the emulsion, and stirred and reacted at 60 °C for 4 h to form a SiO2 shell layer; after the reaction is completed, 2 parts of Fe3O4 nanoparticles are added, and stirring is continued for 2 h to embed Fe3O4 in the shell layer; the microcapsules are collected by centrifugation (3000 rpm, 20 min), washed 3 times with deionized water, and vacuum dried at 60 °C to obtain the magnetic microcapsules.

[0070] In a specific implementation, the preparation method of the rare earth MOF loaded with dopamine derivatives is as follows: By weight, 3 parts of europium nitrate and 6 parts of 2-methylimidazole are dissolved in 80 parts of methanol by ultrasonic treatment; transferred to a high-pressure reaction kettle and reacted at 120 °C for 6 h; the blue crystals are collected by centrifugation, washed 3 times with methanol, and vacuum dried at 80 °C to obtain an europium-organic framework material; 3 parts of the europium-organic framework material are dispersed in 60 parts of N,N-dimethylformamide, 2 parts of N-acryloyldopamine are added, and stirred at 60 °C for 2 h under nitrogen protection; the solid is collected by centrifugation (4000 rpm, 10 min), washed 3 times with N,N-dimethylformamide, and vacuum dried at 60 °C to obtain the rare earth MOF loaded with dopamine derivatives.

[0071] Example 5 An embodiment of the present invention provides a highly wear-resistant and anti-aging polyurethane vehicle film, which is different from Example 4 in that it includes the following raw materials in parts by weight: 70 parts of polyurethane matrix, 20 parts of modified composite filler, 12 parts of magnetic microcapsules, and 5 parts of rare earth MOF loaded dopamine derivative.

[0072] Comparative Example 1: Compared with Example 3, the modified composite filler only contains modified graphene oxide and photo-responsive hyperbranched polysiloxane (mass ratio 1.5:1), and the total amount remains 15 parts.

[0073] Comparative Example 2: Compared with Example 3, the modified composite filler only contains dynamically grafted polyrotaxane and modified graphene oxide (mass ratio 2.5:1.5), and the total amount remains 15 parts.

[0074] Comparative Example 3: Compared with Example 3, the microcapsules are directly blended into the polyurethane matrix without applying a magnetic field.

[0075] Comparative Example 4: Compared with Example 3, the rare earth MOF loaded dopamine derivative is replaced with an equal amount of benzotriazole UV-327.

[0076] Comparative Example 5: Compared with Example 3, only 15 parts of modified graphene oxide are used in the modified composite filler.

[0077] Performance Test The polyurethane vehicle films of Example 3 and Comparative Examples 1-5 were subjected to performance tests, and the test results are shown in Table 1 below: Table 1 Performance Test Results Table of Polyurethane Vehicle Films

[0078] It can be seen from the above results that the vehicle film of the present invention has good wear resistance and anti-aging performance. By adding the modified composite filler, the wear amount is greatly reduced, and the wear resistance is improved. By adding the anti-aging system of rare earth MOF loaded dopamine derivative, the anti-aging performance is improved.

[0079] It should be noted that for the foregoing embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps may be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0080] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on these embodiments, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still, without conflict and without making creative efforts, combine, add or delete the features in the embodiments of the present invention according to the circumstances or make other adjustments, so as to obtain different technical solutions that essentially do not deviate from the concept of the present invention, and these technical solutions also fall within the scope of protection of the present invention.

Claims

1. A highly wear-resistant and anti-aging polyurethane vehicle film, characterized in that, It comprises the following raw materials in parts by weight: 60 - 70 parts of polyurethane matrix, 10 - 20 parts of modified composite filler, 5 - 12 parts of magnetic microcapsules, and 1 - 5 parts of anti-aging agent. The modified composite filler includes dynamically grafted polyrotaxane, modified graphene oxide, and photo-responsive hyperbranched polysiloxane. The magnetic microcapsules are distributed in the near-surface area of the vehicle film through magnetic field-assisted orientation, and the anti-aging agent is a rare earth MOF-loaded dopamine derivative.

2. The highly wear-resistant and anti-aging polyurethane vehicle film according to claim 1, characterized in that, It comprises the following raw materials in parts by weight: 62 - 68 parts of polyurethane matrix, 13 - 17 parts of modified composite filler, 7 - 10 parts of magnetic microcapsules, and 2 - 4 parts of anti-aging agent.

3. The highly wear-resistant and anti-aging polyurethane vehicle film according to claim 2, characterized in that, It comprises the following raw materials in parts by weight: 65 parts of polyurethane matrix, 15 parts of modified composite filler, 8.5 parts of magnetic microcapsules, and 3 parts of anti-aging agent.

4. The highly wear-resistant and anti-aging polyurethane vehicle film according to claim 1, characterized in that, The mass ratio of dynamically grafted polyrotaxane, modified graphene oxide, and photo-responsive hyperbranched polysiloxane in the modified composite filler is 2 - 3:1 - 2:

1.

5. The highly wear-resistant and anti-aging polyurethane vehicle film according to claim 1, characterized in that, The preparation method of the dynamically grafted polyrotaxane is as follows: By weight, 8 - 12 parts of α-cyclodextrin are dissolved in 100 - 120 parts of deionized water, and stirred at 65 - 75 °C until completely dissolved; a solution prepared by mixing 4 - 6 parts of polyethylene glycol with 100 - 120 parts of deionized water is slowly added dropwise, and the dropping rate is controlled at 1 mL / min; after the addition is complete, the temperature is raised to 75 - 85 °C, and the reaction is carried out at a constant temperature for 3 - 5 h; the reaction solution is cooled to room temperature, filtered, washed 3 times with acetone, and vacuum dried to obtain a white filamentous polyrotaxane matrix; the polyrotaxane matrix is dispersed in 100 - 120 parts of anhydrous toluene, 5 parts of isocyanatopropyltriethoxysilane and 0.1 - 0.3 parts of dibutyltin dilaurate are added under nitrogen protection, the temperature is raised to 90 °C, and the reaction is carried out for 2 - 4 h; after the reaction is completed, the product is collected by centrifugation, washed 3 times with toluene, and vacuum dried at 60 - 70 °C to obtain the dynamically grafted polyrotaxane.

6. The highly wear-resistant and anti-aging polyurethane vehicle film according to claim 1, wherein The preparation method of the modified graphene oxide is as follows: By weight, 1 - 2 parts of graphene oxide are dispersed in 100 - 120 parts of deionized water, and ultrasonic treatment is carried out for 1 - 2 h; 5 - 8 parts of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide are added, and stirred at 60 °C for 2 - 3 h; centrifuged and washed, and vacuum dried at 60 °C to obtain the modified graphene oxide.

7. The highly wear-resistant and anti-aging polyurethane vehicle film according to claim 1, wherein, The preparation method of the light-responsive hyperbranched polysiloxane is as follows: by weight, add 15-25 parts of methyltrimethoxysilane to 150-250 parts of ethanol / water mixed solvent, stir at room temperature for 10-30 min; slowly add 3-7 parts of ammonia water, control the reaction temperature ≤ 30 °C; after the addition is complete, raise the temperature to 50 °C and react for 1-2 h; dialyze and purify, freeze-dry to obtain a colorless transparent hyperbranched polysiloxane. Disperse the hyperbranched polysiloxane in 150-200 parts of tetrahydrofuran, add 4-6 parts of triethylamine, and cool to 0 °C in an ice bath under nitrogen protection; slowly add a solution prepared by mixing 6-10 parts of cinnamoyl chloride and 15-20 parts of tetrahydrofuran, control the dropping rate at 0.5 mL / min; after the addition is complete, raise the temperature to 25-30 °C and react for 24 h; filter to remove salt precipitation, rotary evaporate to remove the solvent to obtain the light-responsive hyperbranched polysiloxane.

8. The highly wear-resistant and anti-aging polyurethane vehicle film according to claim 1, wherein The preparation method of the magnetic microcapsules is as follows: by weight, disperse 4-6 parts of Fe3O4 nanoparticles in 50-80 parts of ethanol, add 1-3 parts of silane coupling agent KH550, ultrasonically treat for 30-50 min, and dry at 60-70 °C for standby; mix 8-12 parts of polyurethane prepolymer and 1-3 parts of modified Fe3O4 nanoparticles, add 50-60 parts of toluene, and ultrasonically disperse for 30-50 min to form a homogeneous oil phase; dissolve 5-7 parts of polyvinyl alcohol in 200-300 parts of deionized water and heat to 60 °C to dissolve to obtain an aqueous phase; slowly add the oil phase to the aqueous phase and perform high-speed shear emulsification to form a W / O emulsion; add 2-4 parts of tetraethoxysilane and 1-3 parts of ammonia water to the emulsion, stir and react at 60 °C for 2-4 h to form a SiO2 shell layer; after the reaction is completed, add 1-2 parts of Fe3O4 nanoparticles and continue to stir for 1-2 h to embed Fe3O4 in the shell layer; centrifuge to collect the microcapsules, wash 3 times with deionized water, and vacuum dry at 60 °C to obtain the magnetic microcapsules.

9. The highly wear-resistant and anti-aging polyurethane vehicle film according to claim 1, wherein The preparation method of the rare earth MOF loaded with dopamine derivatives is as follows: by weight, dissolve 1-3 parts of europium nitrate and 4-6 parts of 2-methylimidazole in 50-80 parts of methanol by ultrasonic dissolution; transfer to a high-pressure reaction kettle and react at 120 °C for 4-6 h; centrifuge to collect blue crystals, wash 3 times with methanol, and vacuum dry at 80 °C to obtain europium-organic framework materials; disperse 1-3 parts of europium-organic framework materials in 20-60 parts of N,N-dimethylformamide, add 1-2 parts of N-acryloyldopamine, and stir at 60 °C for 1-2 h under nitrogen protection; centrifuge to collect the solid, wash 3 times with N,N-dimethylformamide, and vacuum dry at 60 °C to obtain the rare earth MOF loaded with dopamine derivatives.

10. The preparation method of the highly wear-resistant and anti-aging polyurethane vehicle film according to any one of claims 1-9, characterized in that, It includes the following steps: Prepare each raw material according to the ratio; Disperse the polyurethane prepolymer, modified composite filler, magnetic microcapsules and rare earth MOF loaded with dopamine derivative dispersion liquid by core-shell structure laminar flow assembly through a microfluidic process; Apply a gradient magnetic field of 0.5-1.5 T during the coating process to make the microcapsules migrate to the set area; Perform ultraviolet pre-curing and thermal curing in sequence to form a gradient cross-linked structure.

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