Anti-ultraviolet high-flame-retardant polyester fiber and preparation method thereof

Abstract

The invention discloses an anti-ultraviolet high-flame-retardant polyester fiber and a preparation method thereof. The polyester fiber is prepared from the following raw materials in parts by weight: 100 parts of polyester chips, 20-60 parts of core-shell flame-retardant anti-ultraviolet particles and 2-4.5 parts of an anti-dripping agent. According to the invention, a porous alumina-titanium dioxide compound is used as a carrier, a magnesium hydroxide flame retardant, iron-doped carbon dots with photo-thermal performance and auxiliaries (an antioxidant and an ultraviolet light absorber) are combined with the carrier to construct a structural system loaded with multiple active components: functionalized flame-retardant particles, and then a polyurethane microporous membrane is coated, so that the flame-retardant polyurethane composite material is obtained. The core-shell type flame-retardant anti-ultraviolet particles are added into polyester fibers, so that the anti-ultraviolet performance and the flame-retardant performance of the polyester fibers can be remarkably improved. The polyester fiber provided by the invention can adaptively increase the release rate of the ultraviolet absorbent and the antioxidant when the ultraviolet property is enhanced in the environment, so that more optimized protection can be provided for a polyester fiber matrix at the moment.

Description

Technical Field

[0001] The present invention relates to the field of polyester fiber materials, and in particular to an anti-ultraviolet and highly flame-retardant polyester fiber and a preparation method thereof. Background Art

[0002] Polyester, commonly known as "terylene," is a synthetic fiber made from the chemical polycondensation of organic dibasic acids and diols. It offers numerous advantages, including high breaking strength and elastic modulus, moderate resilience, excellent heat setting, good abrasion resistance, chemical stability, heat and light resistance, good corrosion resistance, and stability to weak acids and bases. It is widely used in the manufacture of home textiles and industrial textiles.

[0003] When polyester fibers are used in outdoor environments, such as tarpaulins, vehicle roofs, ropes, packaging materials (such as non-woven fabrics for cement and gravel bags), non-woven polyester fiber fabrics for construction, and other industrial non-woven fabrics, they face significant challenges in maintaining their UV and antioxidant properties due to the unavoidable presence of high levels of UV radiation and the attack of oxidizing substances. These properties can be enhanced by adding UV absorbers and / or inorganic fillers with UV resistance, as well as antioxidants. Traditionally, UV absorbers and antioxidants have been added directly to the polyester system. Examples include patents CN111979585A, which discloses a method for preparing a thermally insulating and moisture-conducting multifunctional polyester fiber; CN105802146A, which discloses a method for preparing a flexible polyester fiber strapping tape; CN120041963A, which discloses an antibacterial elastic polyester fiber; and CN119956520A, which discloses a process for spinning matte PET fiber chips. The main problems with this approach are: when the added amount is small, the UV and aging resistance is short-lived; when the added amount is large, compatibility issues can easily lead to aggregation, affecting the performance of the polyester. Furthermore, when UV absorbers and antioxidants are directly and extensively exposed to the polyester system, they lose effectiveness due to decomposition and surface migration, shortening the UV and aging resistance. Constructing a sustained-release system can achieve long-term release of active ingredients and prolong their efficacy, as exemplified by patents CN120158132A, which discloses a sustained-release anti-yellowing additive and its application in coatings, and CN120098689A, which discloses a sustained-release antioxidant and its preparation method and application. However, in such solutions, the release rate of the active ingredient is not controllable. For example, for UV absorbers, regardless of whether the UV rays in the environment become stronger or weaker, the release rate of the UV absorber remains unaffected, relying solely on the sustained-release system itself. If the release rate and amount of the UV absorber can be adaptively increased when the ultraviolet rays in the environment become stronger, then the substrate can be provided with better and more intelligent anti-UV function at this time. Obviously, the above solutions cannot achieve this goal.

[0004] Therefore, it is necessary to improve the existing technology to provide a more reliable solution. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an anti-ultraviolet and highly flame-retardant polyester fiber and a preparation method thereof in view of the deficiencies in the above-mentioned prior art.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions: In a first aspect of the present invention, a highly flame-retardant anti-ultraviolet polyester fiber is provided, wherein the raw materials for preparing the fiber comprise the following components by weight: 100 parts of polyester chips, 20-60 parts of core-shell flame-retardant anti-ultraviolet particles, and 2-4.5 parts of an anti-dripping agent; the core-shell flame-retardant anti-ultraviolet particles are prepared by the following method:

[0007] S1. preparing a porous support, wherein the porous support is a composite of porous alumina and titania;

[0008] S2. Loading magnesium hydroxide on a porous carrier to obtain flame retardant particles;

[0009] S3, modifying the flame retardant particles with a photothermal agent to obtain functionalized flame retardant particles, wherein the photothermal agent is a carbon dot with photothermal properties;

[0010] S4, loading additives onto the functionalized flame retardant particles to obtain core particles, wherein the additives include an antioxidant and a UV absorber;

[0011] S5. Coating the core particles with a polyurethane microporous membrane to obtain core-shell flame-retardant and anti-ultraviolet particles.

[0012] Preferably, the anti-dripping agent is at least one of melamine, benzoguanamine, and triallyl isocyanurate; the antioxidant is at least one of antioxidant 1010, antioxidant 618, antioxidant 1076, and antioxidant 1098; and the ultraviolet absorber is at least one of UV-P, UV-1, UV-9, UVBP-4, UV-234, and UVP-327.

[0013] Preferably, the core-shell flame retardant and anti-ultraviolet particles are prepared by the following method:

[0014] S1. Preparation of a porous support: using tetrabutyl titanate as a titanium source, Al(NO3)3·9H2O as an aluminum source, hexadecyltrimethylammonium bromide as a template, and ammonium bicarbonate as a precipitant, to prepare a porous alumina and titania composite, i.e., a porous support, by hydrothermal reaction and calcination;

[0015] S2, mixing and reacting a porous carrier, MgCl2, and NaOH, and loading magnesium hydroxide on the porous carrier to obtain flame retardant particles;

[0016] S3, loading magnesium hydroxide: taking glucose, ferric citrate, 2', 7'-dichlorodihydrofluorescein diacetate, 4-dimethylaminopyridine and indocyanine green as raw materials, a mixture of ethanol and water as solvent, in-situ synthesis of carbon dots with photothermal performance on the flame-retardant particles by hydrothermal method to obtain functionalized flame-retardant particles, and the carbon dots are photothermal agents;

[0017] S4, loading auxiliary agent: loading auxiliary agent on the functionalized flame-retardant particles by supergravity assisted impregnation method to obtain core particles, and the auxiliary agent includes antioxidant and ultraviolet absorber;

[0018] S5, coating polyurethane microporous membrane: coating polyurethane microporous membrane on the core particles to obtain core-shell type flame-retardant ultraviolet resistant particles.

[0019] Preferably, step S1 is specifically:

[0020] Tetrabutyl titanate is added to n-butanol to obtain A liquid, AI (NO3) 3·9H2O and cetyltrimethylammonium bromide are added to deionized water, and then ammonium bicarbonate is added, after stirring, A liquid is added, the obtained mixture is added to a reaction kettle, and the reaction is carried out at 150-170℃ for 6-24h, and the solid product is calcined at 400-550℃ for 2-8h to obtain a porous carrier.

[0021] Preferably, step S2 is specifically: the porous carrier is dispersed in deionized water, MgCl2 is added, and NaOH aqueous solution is added dropwise, after dropwise addition is completed, stirring reaction is carried out at 40-60℃ for 1-4h, and then filtration, washing and drying are carried out to obtain flame-retardant particles.

[0022] Preferably, step S3 is specifically:

[0023] S3-1, dispersing the flame-retardant particles and ferric citrate in deionized water at a temperature of 60-80℃ to obtain a mixed solution 1; adding glucose, 2', 7'-dichlorodihydrofluorescein diacetate, 4-dimethylaminopyridine and indocyanine green into a mixed solvent composed of ethanol and deionized water, and stirring to obtain a mixed solution 2;

[0024] S3-2, adding the mixed solution 2 to the mixed solution 1, and then transferring the obtained precursor solution into a reaction kettle, and carrying out reaction at 165-190℃ for 4-16h, and then carrying out suction filtration, washing and drying to obtain functionalized flame-retardant particles.

[0025] Preferably, step S4 is specifically:

[0026] S4-1, adding antioxidant and ultraviolet absorber into acetone to prepare an auxiliary agent impregnation solution with an antioxidant concentration of 5-20g / L and an ultraviolet absorber concentration of 3-12g / L;

[0027] S4-2. Add functionalized flame retardant particles to the impregnation solution, ultrasonically disperse for 0.5-2 hours, and then place them in a high-gravity packed bed. Treat them under high-gravity conditions of 25-100 times the acceleration of gravity for 2-8 hours, remove them, let them stand for 1-4 hours, filter, wash, and dry them to obtain core particles.

[0028] Preferably, step S5 is specifically:

[0029] S5-1. PPG, TDI, and hydroxypropyl silicone oil are added to acetone, heated to 55-75°C, triethylenediamine is added dropwise, and the mixture is stirred for 1-3 hours. Butanediol and ethylenediamine are added, and the mixture is stirred at 70-75°C for 1.5-6 hours. Acetone is removed by vacuum distillation to obtain a modified polyurethane emulsion.

[0030] S5-2. Take the modified polyurethane emulsion, core particles, and polyethylene glycol and add them to a mixed solution of butanone and DMF. Stir and react at 65-75°C for 15-60 minutes, let it stand for 5-30 minutes, and centrifuge. Add the obtained solid product to DMF, stir, and filter. Add the solid product to deionized water at a temperature of 70-80°C, stir for 2-8 hours, filter, and dry for 1 hour to obtain core-shell flame retardant and anti-UV particles.

[0031] Preferably, the core-shell flame retardant and anti-ultraviolet particles are prepared by the following method:

[0032] S1. Preparation of porous carrier:

[0033] 0.85-3.4 mL of tetrabutyl titanate was added to 25-100 mL of n-butanol and stirred for 2-10 min to obtain solution A; 5-20 g of AI(NO3)3·9H2O and 0.12-0.5 g of hexadecyltrimethylammonium bromide were added to 75-300 mL of deionized water and stirred for 5-20 min, followed by 4-16 g of ammonium bicarbonate and stirring for 15-60 min. Solution A was added and ultrasonic dispersion was performed for 0.5-2 h. The resulting mixture was added to a reactor and reacted at 150-170°C for 6-24 h. The mixture was cooled to room temperature, filtered, washed, dried, calcined at 650-750°C for 2-8 h, and ground to obtain a porous carrier;

[0034] S2. Loading magnesium hydroxide on a porous carrier:

[0035] Take 2.5-10g of the porous carrier and disperse it in 100-400mL of deionized water. Add 1.5-6.3g of MgCl2. Add 30-150mL of 1mol / L NaOH aqueous solution dropwise while stirring. Stir and react at 40-60℃ for 1-4h. Filter, wash, and dry to obtain flame-retardant particles.

[0036] S3. Modifying the photothermal agent on the flame retardant particles:

[0037] S3-1, 2.5-10 g flame-retardant particles, 612-2450 mg iron citrate were dispersed in 50-200 mL deionized water with a temperature of 60-80℃ to obtain a mixed solution 1; 450-1800 mg glucose, 200-814 mg 2', 7'-dichlorodihydrofluorescein diacetate, 122-488 mg 4-dimethylaminopyridine and 220-930 mg indocyanine green were added to a mixed solvent composed of 20-80 mL ethanol and 30-120 mL deionized water, and stirred for 5-30 min to obtain a mixed solution 2;

[0038] S3-2, the mixed solution 2 was added to the mixed solution 1 under stirring, and ultrasonic dispersion was performed at 60-80℃ for 5-20 min; the obtained precursor solution was transferred into a reaction kettle, and reaction was performed at 165-190℃ for 4-16 h; after cooling, suction filtration, washing and drying were performed to obtain functionalized flame-retardant particles;

[0039] S4, loading an auxiliary agent on the functionalized flame-retardant particles:

[0040] S4-1, an antioxidant and an ultraviolet absorber were added to acetone, and stirred uniformly to prepare an auxiliary agent impregnation solution with an antioxidant concentration of 5-20 g / L and an ultraviolet absorber concentration of 3-12 g / L;

[0041] S4-2, 2.5-10 g functionalized flame-retardant particles were added to 50-200 mL of the impregnation solution, ultrasonic dispersion was performed for 0.5-2 h, and then the particles were placed in a high gravity packed bed, treated under a high gravity condition of 100-400 times gravity acceleration for 2-8 h, taken out, and left to stand for 1-4 h; after filtration, washing and drying, core particles were obtained;

[0042] S5, coating a polyurethane microporous membrane on the core particles:

[0043] S5-1, 2.5-10 g PPG, 1.75-7 g TDI and 0.7-2.8 g hydroxypropyl silicone oil were added to 50-200 mL acetone, and the temperature was raised to 55-75℃ under nitrogen protection; then 0.005-0.03 g triethylenediamine was added dropwise, and stirring reaction was performed at 1-3 h; 1-4 mL butanediol and 0.4-1.6 mL ethylenediamine were added, and stirring reaction was performed at 70-75℃ for 1.5-6 h; after the temperature was lowered to room temperature, acetone was removed by reduced pressure distillation to obtain a modified polyurethane emulsion;

[0044] S5-2. Take 2.5-10g of modified polyurethane emulsion, 1.25-5g of core particles, and 0.28-1.12g of polyethylene glycol, add them to a mixed solution consisting of 15-60mL of butanone and 15-60mL of DMF, stir for 5-30min, react with stirring at 65-75°C for 15-60min, let it stand for 5-30min, cool to room temperature and then centrifuge, add the obtained solid product to 25-100mL of DMF, stir for 5-20min, filter, add the solid product to 50-200mL of deionized water at a temperature of 70-80°C, stir for 2-8h, filter and dry to obtain core-shell flame retardant and anti-UV particles.

[0045] Preferably, the core-shell flame retardant and anti-ultraviolet particles are prepared by the following method:

[0046] S1. Preparation of porous carrier:

[0047] 1.7 mL of tetrabutyl titanate was added to 50 mL of n-butanol and stirred for 5 min to obtain solution A. 10 g of AI(NO3)3·9H2O and 0.25 g of hexadecyltrimethylammonium bromide were added to 150 mL of deionized water and stirred for 10 min, followed by 7.9 g of ammonium bicarbonate. After stirring for 30 min, solution A was added and ultrasonic dispersion was performed for 1 h. The resulting mixture was added to a reactor and reacted at 160°C for 12 h. The mixture was cooled to room temperature, filtered, washed, dried, calcined at 700°C for 4 h, and ground to obtain a porous support.

[0048] S2. Loading magnesium hydroxide on a porous carrier:

[0049] 5 g of the porous support was added to 200 mL of deionized water and ultrasonically dispersed for 30 minutes. 3.15 g of MgCl2 was then added and stirred for 15 minutes. 75 mL of a 1 mol / L aqueous NaOH solution was then added dropwise with stirring. After the addition was complete, the mixture was stirred at 50°C for 2 hours, filtered, washed, and dried to obtain flame-retardant particles.

[0050] S3. Modifying the photothermal agent on the flame retardant particles:

[0051] S3-1. Add 5 g of flame retardant particles and 1225 mg of ferric citrate to 100 mL of deionized water at 70° C. and ultrasonically disperse for 30 min to obtain mixed solution 1. Add 900 mg of glucose, 407 mg of 2',7'-dichlorodihydrofluorescein diacetate, 244 mg of 4-dimethylaminopyridine, and 465 mg of indocyanine green to a mixed solvent consisting of 40 mL of ethanol and 60 mL of deionized water and stir for 15 min to obtain mixed solution 2.

[0052] S3-2, adding the mixed solution 2 to the mixed solution 1 under stirring, ultrasonically dispersing at 70°C for 10 minutes to obtain a precursor solution, transferring the precursor solution into a polytetrafluoroethylene-lined reactor, reacting at 175°C for 8 hours, cooling, filtering, washing, and drying to obtain functionalized flame retardant particles;

[0053] S4. Loading additives on functionalized flame retardant particles:

[0054] S4-1, adding an antioxidant and a UV absorber to acetone, stirring evenly, to prepare an additive impregnation solution having an antioxidant concentration of 10 g / L and a UV absorber concentration of 6 g / L;

[0055] S4-2. 5 g of functionalized flame-retardant particles were added to 100 mL of the impregnation solution, subjected to ultrasonic dispersion for 1 h, and then placed in a high-gravity packed bed. After treatment under high-gravity conditions of 150 times the acceleration of gravity for 4 h, the particles were removed from the high-gravity packed bed, allowed to stand for 2 h, filtered, washed, and dried to obtain core particles.

[0056] S5. Coating the core particles with a polyurethane microporous membrane:

[0057] S5-1. Add 5 g of PPG, 3.5 g of TDI, and 1.4 g of hydroxypropyl silicone oil to 100 mL of acetone, and heat to 65°C under nitrogen. Then, add 0.015 g of triethylenediamine dropwise, and stir to react for 1.5 h. Then, add 2 mL of butanediol and 0.8 mL of ethylenediamine, and stir to react at 72°C for 3 h. Then, cool to room temperature, and remove acetone by vacuum distillation to obtain a modified polyurethane emulsion.

[0058] S5-2. Take 5g of modified polyurethane emulsion, 2.5g of core particles, and 0.56g of polyethylene glycol, add them to a mixed solution consisting of 30mL of butanone and 30mL of DMF, stir for 15min, react with stirring at 70°C for 30min, let it stand for 15min, cool to room temperature and then centrifuge. The obtained solid product is added to 50mL of DMF, stirred for 10min, filtered, and the solid product is added to 100mL of deionized water at 75°C, stirred for 4h, filtered, and the solid product is vacuum dried at 50°C for 12h to obtain core-shell flame retardant and anti-UV particles.

[0059] The present invention also provides a method for preparing the above-mentioned UV-resistant and highly flame-retardant polyester fiber, comprising the following steps:

[0060] 1) The polyester chips are vacuum dried at 100-120° C. for 6-24 hours, and then stirred and mixed with core-shell flame retardant and anti-UV particles and an anti-dripping agent to obtain a polyester mixture;

[0061] 2) Melting and extruding the polyester mixture at 230-245° C., spinning the resulting melt to obtain UV-resistant and highly flame-retardant polyester fibers at a spinning temperature of 250-270° C. and a spinning speed of 600-900 m / min.

[0062] Invention mechanism:

[0063] 1. Preparation Mechanism

[0064] (1) First, Al(NO3)3·9H2O is used as an aluminum source, hexadecyltrimethylammonium bromide is used as a template, and ammonium bicarbonate is used as a precipitant. Alumina with a porous structure is prepared by a traditional hydrothermal reaction combined with a calcination method. The special feature of the present invention is that tetrabutyl titanate is used as a titanium source, and titanium dioxide is doped into the porous alumina to obtain a porous alumina-titania composite, i.e., a porous carrier, which is denoted as TiO2-Al2O3.

[0065] TiO2-Al2O3 acts as a carrier for loading various active components (magnesium hydroxide, carbon dots, and additives), and its porous structure provides a sustained release of these additives. Furthermore, the addition of alumina to polyester fibers enhances their wear resistance, strength, and thermal stability, helping to improve their flame retardancy. The doped titanium dioxide exhibits excellent UV absorption and improves the fiber's strength, weather resistance, and heat resistance.

[0066] (2) Then, taking advantage of the porous carrier's well-developed pore structure and large specific surface area, magnesium hydroxide was loaded onto it as a flame retardant to obtain flame-retardant particles, designated TiO2-Al2O3@Mg(OH)2. Magnesium hydroxide, a commonly used inorganic flame retardant, releases water molecules and absorbs a large amount of heat when thermally decomposed, thereby lowering the temperature of the polyester fiber, delaying or preventing the combustion process, and significantly improving the flame retardant properties of the polyester fiber.

[0067] (3) Then, glucose, 2',7'-dichlorodihydrofluorescein diacetate, 4-dimethylaminopyridine and indocyanine green were used as composite carbon sources and ferric citrate was used as the doping component. Iron-doped carbon dots with photothermal properties were synthesized in situ on flame-retardant particles by a one-pot hydrothermal method. The carbon dots were photothermal agents, and functionalized flame-retardant particles were obtained, which were recorded as TiO2-Al2O3@Mg(OH)2@Fe-CDs. During the preparation process, on the one hand, the adsorption effect of the rich pore structure of TiO2-Al2O3@Mg(OH)2 allows the composite carbon source and other components to be adsorbed onto the surface of TiO2-Al2O3@Mg(OH)2 or enter its pores. On the other hand, ferric citrate is first mixed with TiO2-Al2O3@Mg(OH)2, and the iron ions are combined with the hydroxyl groups on the surface of TiO2-Al2O3@Mg(OH)2 through coordination and other effects. Afterwards, the iron ions can also simultaneously combine with the components in the composite carbon source through coordination with functional groups such as carboxyl and amino groups, so that each component can be adsorbed in large quantities by TiO2-Al2O3@Mg(OH)2, creating favorable conditions for the in situ deposition preparation of carbon dots on TiO2-Al2O3@Mg(OH)2.

[0068] The iron-doped carbon dots synthesized by in situ modification in the present invention have excellent ultraviolet absorption properties, which can significantly improve the ultraviolet resistance of polyester fibers. At the same time, they also exhibit good photothermal properties (the performance of converting light energy into thermal energy), and can achieve a local warming effect while absorbing ultraviolet rays. They can be used as an excellent photothermal agent. In the core-shell flame-retardant and anti-ultraviolet particle structure system constructed by the present invention, they can play the role of "adaptive intelligent adjustment" of the micropores of the polyurethane microporous membrane according to the environmental ultraviolet content.

[0069] It has been reported that 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) was used as a carbon source to prepare carbon dots with photothermal properties. Lv Ju et al. prepared a Cu-doped carbon dot with photothermal properties by hydrothermal reaction of DCFH-DA and Cu2+, and verified its red light photothermal properties. It can be used as a photothermal agent in photothermal therapy (Preparation, Characterization and Performance of Photothermal and Photodynamic Synergistic Antibacterial Carbon Dots [J]. Fine Chemicals, 2024, 41(8):1745-1753.). However, after testing, its photothermal efficiency was only 21.7% (808 nm laser irradiation), and it is necessary to further improve its photothermal efficiency. In order to prepare carbon dots with ultraviolet photothermal properties in the present invention, a series of improvements were made on the basis of the above, and glucose, 4-dimethylaminopyridine and indocyanine green were added as composite carbon sources, and Fe with variable valence was used. 3+ Replace Cu 2+ After doping, the carbon dots finally prepared showed excellent ultraviolet absorption ability and ultraviolet photothermal performance, and the photothermal efficiency could reach 45.2%.

[0070] Among them, Fe 3+ Doping with 4-dimethylaminopyridine can change the electron cloud distribution of carbon dots, increase the electron cloud density, form new impurity energy levels, narrow the band gap width of the material, and thus expand the light absorption range; and by anchoring iron in the carbon dot skeleton, it exposes more active sites, thereby enhancing the capture efficiency of incident photons, ultimately improving light absorption efficiency and energy utilization, enhancing ultraviolet absorption performance and photothermal efficiency. The addition of 4-dimethylaminopyridine can enrich the strong electron-donating groups in the carbon dots, improving the absorption coefficient and photothermal performance, which is consistent with the report in the literature "Dongmei Xi, Ming Xiao, Jianfang Cao, Luyang Zhao, Ning Xu, Saran Long, Jiangli Fan, Kun Shao, Wen Sun*, Xuehai Yan, and Xiaojun Peng*. NIR Light-Driving Barrier-Free Group Rotation in Nanoparticles with an 88.3% Photothermal Conversion Efficiency for Photothermal Therapy. Adv. Mater. 2020, 32, 190785". Indocyanine green (ICG) is a near-infrared fluorescent dye with high absorbance.

[0071] (4) Then, the functionalized flame retardant particles are loaded with antioxidants and ultraviolet absorbers by means of the high gravity assisted impregnation method, thereby obtaining core particles. Due to the high gravity assisted impregnation method, the efficiency and loading amount of the impregnation loading can be improved, and the antioxidants and ultraviolet absorbers are loaded in the pores, which can achieve a better sustained release effect, thereby enabling the antioxidants and ultraviolet absorbers to be released long-term and slowly in the polyester fiber matrix, providing a more lasting effect, and effectively avoiding the aggregation and surface migration of the antioxidants and ultraviolet absorbers in the polyester system, which may cause their premature failure, and slowing down their adverse effects on the polyester fiber matrix.

[0072] (5) Finally, a polyurethane microporous membrane is coated on the core particle to obtain a core-shell type flame-retardant and ultraviolet-resistant particle. In this process, hydroxypropyl silicone oil is added to the conventional polyurethane preparation raw materials PPG and TDI, and triethylenediamine is used as a catalyst to prepare a modified polyurethane emulsion. Then, through the traditional solvent-non-solvent method (Wang Q J, Zhang Y Z, Yang Y, et al. Influence of different pore-forming agents on the permeability of polyurethane microporous membranes [J]. Leather Science and Engineering, 2011(3):6. DOI:10.3969 / j.issn.1004-7964.2011.03.005.), polyethylene glycol is used as a pore-forming agent, DMF is used as a solvent, and water is used as a non-solvent. The core particle is blended with the modified polyurethane emulsion to coat a polyurethane microporous membrane on the core particle.

[0073] In the first aspect, one of the defects of inorganic reinforcing particles TiO2, Al2O3, and Mg(OH)2 in the application of polyester fiber systems is poor compatibility with the system and difficulty in uniform dispersion. In addition, TiO2 as an ultraviolet-resistant active component and Mg(OH)2 as a flame-retardant active component in the polyester system also have problems such as premature failure of component activity and deterioration of base material performance due to aggregation, surface migration, and other reasons. The coating of a polyurethane microporous membrane can significantly improve the compatibility of the core particle with the polyester fiber system, and in combination with the multi-component organic structure on the core particle, it can simultaneously solve the problem of the difficulty of uniform dispersion of inorganic components TiO2, Al2O3, Mg(OH)2, and Fe-CDs in the polyester fiber system. In addition, after coating with a polyurethane microporous membrane, TiO2 and Mg(OH)2 avoid direct contact with polyester, which can reduce their negative impact on the performance of the polyester system, slow down phenomena such as aggregation and surface migration in the polyester system, and the polyurethane microporous membrane has a certain shielding effect on TiO2, which can prevent its ultraviolet absorption activity from being prematurely consumed, thus playing a certain slow-release performance and prolonging its effect. When a fire occurs, the polyurethane microporous membrane rapidly expands and melts at high temperatures, fully exposing Mg(OH)2, which does not affect the timely play of its flame-retardant effect.

[0074] In the second aspect, polyurethane also has good elasticity and wear resistance, and its addition to polyester fiber can improve the elasticity and comfort of polyester fiber and enhance the durability of the fabric. The addition of hydroxypropyl silicone oil can improve the water-repellent performance (Chen Z F, Lin W H. Synthesis and application of comb-shaped waterborne polyurethane coated silicone fluorine-free high-efficiency water-repellent agent [J]. Guangzhou Chemical Industry, 2023, 51(11):71-74.) and improve the waterproof ability of polyester fiber.

[0075] Thirdly, unlike conventional polymer coating modification methods, the present invention coats a polyurethane film with a porous structure on the core particles. This membrane structure, combined with the iron-doped carbon dots with photothermal properties inside, can achieve "adaptive regulation" of UV resistance and antioxidant properties. The regulation result is that the stronger the ultraviolet rays, the greater the amount of antioxidants and UV absorbers released from the core-shell flame-retardant anti-UV particles, and the more UV-resistant carbon dots and porous carriers are exposed, thereby adaptively enhancing the UV resistance and antioxidant properties provided. The following further explains:

[0076] When the polyester fiber is irradiated with ultraviolet light, the photothermal agent (Fe-CDs) absorbs ultraviolet light, providing an anti-UV effect while simultaneously increasing the local temperature. Thermal expansion and contraction expand the pores of the polyurethane microporous membrane, enhancing the membrane's permeability. Simultaneously, the temperature increase accelerates molecular motion, which promotes the release of antioxidants and UV absorbers loaded into the porous carrier. These two effects combine to release more antioxidants and UV absorbers from the core-shell flame-retardant particles into the polyester fiber system. The increased UV absorber content improves UV absorption, matching the increased UV exposure. Simultaneously, the enhanced membrane permeability increases the exposure of TiO2 and Fe-CDs in the core particles. This increased TiO2 exposure enhances the UV absorption capacity provided by TiO2. However, while absorbing UV light, TiO2 is prone to producing hydroxyl radicals (·OH), a strong oxidizing species that damages the polyester system structure. The increased antioxidant release can promptly capture these strong oxidizing species, thereby avoiding the negative effects of TiO2 on its UV protection. As Fe-CDs are exposed more, they absorb more ultraviolet rays and generate more heat, which promotes the further expansion of the micropores of the polyurethane microporous membrane, thereby producing an anti-ultraviolet gain effect, and ultimately achieving "intelligent adaptive regulation" of anti-ultraviolet and antioxidant properties. This regulatory effect can enable the active components in the system to adaptively adjust the protective performance they provide according to changes in the environment, which can prolong the efficacy of the active components and give full play to the effects of the active components.

[0077] It should be understood that the upper limit of the local temperature rise caused by the core-shell flame-retardant and anti-UV particles of the present invention is far from reaching the level that would cause combustion. After being added to polyester fibers, according to the addition amount range of the present invention, the upper limit of the temperature does not exceed 100°C in normal outdoor applications (in the photothermal performance test, when the core-shell flame-retardant and anti-UV particles were added at the maximum amount, the upper limit of the local maximum temperature in the polyester fiber was approximately 97°C). This is mainly due to the limitations of the light source power (in normal outdoor applications, the ultraviolet light source mainly comes from sunlight, and its intensity is within a normal range), the balance between heat generation and heat dissipation, and the photothermal efficiency of the functionalized flame-retardant particles. Therefore, it does not pose a fire hazard due to temperature rise. However, it should also be noted that due to these photothermal properties, the polyester fiber prepared by the present invention is not suitable for use in textile products that are worn next to the body to avoid burns. However, it is very suitable for many non-wearable products that are used in outdoor environments. Outdoor environments are often inevitably exposed to a large amount of ultraviolet radiation and the invasion of some oxidizing substances, which poses significant challenges to the anti-ultraviolet and antioxidant properties of polyester fibers. The polyester fiber of the present invention has "adaptive regulation" anti-ultraviolet and anti-oxidation properties, which can prolong the anti-ultraviolet and anti-oxidation effects. Therefore, it will be very suitable in these scenarios, such as tarpaulins, car roofs, ropes, packaging materials (such as non-woven fabrics for cement and sand and gravel packaging bags, etc.), non-woven polyester fiber cloth for construction and other industrial non-woven fabrics, etc.

[0078] The beneficial effects of the present invention are:

[0079] The present invention uses a porous alumina-titania composite as a carrier, combining a magnesium hydroxide flame retardant, iron-doped carbon dots with photothermal properties, and additives (antioxidants and ultraviolet absorbers) with it to construct a structural system loaded with multiple active components: functionalized flame-retardant particles are then coated with a polyurethane microporous membrane to obtain core-shell flame-retardant and anti-ultraviolet particles. Adding these particles to polyester fibers can significantly improve the polyester fibers' anti-ultraviolet and flame-retardant properties. The polyester fibers provided by the present invention can adaptively increase the release rate of the ultraviolet absorber and antioxidant when the ultraviolet intensity in the environment increases, thereby providing more optimized protection for the polyester fiber matrix at this time.

[0080] The present invention achieves "adaptive regulation" of UV and antioxidant properties by coating a porous polyurethane membrane around core particles loaded with active ingredients such as antioxidants and UV absorbers. This membrane, combined with iron-doped carbon dots (Cdots) with photothermal properties, results in the release of a greater amount of antioxidants and UV absorbers from the core-shell flame-retardant particles as UV-resistant UV particles increase, exposing more of the UV-resistant Cdots and porous carrier. This adaptive regulation enhances the UV and antioxidant properties, precisely tailored to the specific external environment. This allows the antioxidants and UV absorbers to be utilized more effectively, extending their efficacy and improving the anti-UV effect and longevity of the polyester fiber. This adaptive regulation ensures that the polyester fiber produced by this invention exhibits excellent performance and great potential in non-wearable textile products for outdoor applications, such as tarpaulins, vehicle roofs, ropes, packaging materials (e.g., non-woven fabrics for cement and gravel bags), non-woven polyester fiber fabrics for construction, and other industrial non-woven fabrics. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Figure 1 Infrared absorption spectra of the porous support (TiO2-Al2O3) and functionalized flame retardant particles [TiO2-Al2O3@Mg(OH)2@Fe-CDs] prepared in Example 1;

[0082] Figure 2 Temperature-time curves of the flame-retardant particles [TiO2-Al2O3@Mg(OH)2] and the functionalized flame-retardant particles [TiO2-Al2O3@Mg(OH)2@Fe-CDs] prepared in Example 1;

[0083] Figure 3 The light-to-heat conversion efficiency test results of the core-shell flame-retardant and anti-UV particles in Examples 1-4 and Comparative Examples 2-3 are shown;

[0084] Figure 4 The UV-visible absorption spectra of the core-shell flame-retardant and UV-resistant particles prepared in Example 1, Comparative Example 1 and Comparative Example 4;

[0085] Figure 5 The test results of the ultraviolet absorber release performance of the core-shell flame retardant anti-ultraviolet particles prepared in Example 1;

[0086] Figure 6 These are the test results of the anti-ultraviolet performance (UVA) of the polyester fibers prepared in Examples 1-4 and Comparative Examples 1-6;

[0087] Figure 7 These are the test results of the anti-ultraviolet performance (UVB) of the polyester fibers prepared in Examples 1-4 and Comparative Examples 1-6;

[0088] Figure 8 The flame retardant performance test results of the polyester fibers prepared in Examples 1-4 and Comparative Examples 1-6 are shown;

[0089] Figure 9 The breaking strength test results of the polyester fibers prepared in Examples 1-4 and Comparative Examples 1-6 are shown;

[0090] Figure 10 These are the test results of the breaking strength retention rate of the polyester fibers prepared in Examples 1-4 and Comparative Examples 1-6 after aging. DETAILED DESCRIPTION

[0091] The present invention is further described in detail below with reference to the embodiments so that those skilled in the art can implement the invention with reference to the description.

[0092] It should be understood that terms such as “having”, “including” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof.

[0093] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Materials and reagents used in the following examples are commercially available unless otherwise specified. In the following examples, where specific conditions are not specified, the experiments were conducted under conventional conditions or those recommended by the manufacturer. Reagents and instruments used, where the manufacturer is not specified, are commercially available conventional products.

[0094] The sources of the main raw materials in the following examples and comparative examples are described as follows:

[0095] Polyester chips, model CB-602, relative viscosity 0.8 dl / g, acid value 35 mg KOH / g, Far Eastern Textile Industry (Shanghai) Co., Ltd.

[0096] Triallyl isocyanurate, average particle size 4 μm, Jiangsu Minglin Chemical Technology Co., Ltd.

[0097] Tetrabutyl titanate, hexadecyltrimethylammonium bromide, Jiangsu Minglin Chemical Technology Co., Ltd.;

[0098] 2',7'-Dichlorodihydrofluorescein diacetate (DCFH-DA), CAS number: 4091-99-0, Shanghai Yuanye Biotechnology Co., Ltd.;

[0099] 4-Dimethylaminopyridine, Nanjing Chemical Reagent Co., Ltd.;

[0100] Indocyanine green, brand: Klamar, Shanghai Ziyi Reagent Factory;

[0101] Antioxidant 1010, UV absorber UV-9, Nanjing Milan Chemical Co., Ltd.;

[0102] Hydroxypropyl silicone oil, double-terminated hydroxypropyl silicone oil, 2000 molecular weight, hydroxyl content 1.7%, Hubei Dali Chemical Co., Ltd.

[0103] PPG (polypropylene glycol), polypropylene glycol 2000, Shanghai Hongzhuang Chemical Technology Co., Ltd.;

[0104] Polyethylene glycol, PEG-1000, Hai'an Petrochemical Plant, Jiangsu Province;

[0105] Toluene diisocyanate (TDI), triethylenediamine, Nantong Runfeng Petrochemical Co., Ltd.;

[0106] Magnesium hydroxide, average particle size 5 μm, Nantong Runfeng Petrochemical Co., Ltd.

[0107] Example 1

[0108] A highly flame-retardant, UV-resistant polyester fiber, the raw materials for its preparation comprising the following components by weight: 100 parts of polyester chips, 42 parts of core-shell flame-retardant UV-resistant particles, and 3 parts of an anti-dripping agent; the anti-dripping agent is triallyl isocyanurate;

[0109] The preparation method of the polyester fiber comprises the following steps:

[0110] 1) The polyester chips were vacuum dried at 110° C. for 12 h, and then stirred and mixed with the core-shell flame retardant and anti-UV particles and the anti-dripping agent at 500 rpm for 30 min to obtain a polyester blend;

[0111] 2) adding the polyester mixture into a twin-screw extruder and melt-extruded at 240° C., and spinning the resulting melt to obtain a UV-resistant and highly flame-retardant polyester fiber; wherein the spinning temperature is 265° C., the spinning speed is 750 m / min, the draft ratio is 2 times, and the stretching rate is 700 m / min.

[0112] The core-shell flame retardant and anti-ultraviolet particles are prepared by the following method:

[0113] S1. Preparation of porous carrier:

[0114] 1.7 mL of tetrabutyl titanate was added to 50 mL of n-butanol and stirred for 5 min to obtain solution A. 10 g of Al(NO3)3·9H2O and 0.25 g of hexadecyltrimethylammonium bromide were added to 150 mL of deionized water and stirred for 10 min, followed by 7.9 g of ammonium bicarbonate. After stirring for 30 min, solution A was added and ultrasonic dispersion was performed for 1 h. The resulting mixture was added to a reactor and reacted at 160°C for 12 h. The mixture was cooled to room temperature, filtered, washed, vacuum dried at 90°C for 6 h, calcined at 700°C for 4 h, and ground to obtain a porous support, which was designated as TiO2-Al2O3.

[0115] S2. Loading magnesium hydroxide on a porous carrier:

[0116] 5 g of the porous support was added to 200 mL of deionized water and ultrasonically dispersed for 30 min. 3.15 g of MgCl2 was then added and stirred for 15 min. 75 mL of a 1 mol / L aqueous NaOH solution was then added dropwise with stirring. After the addition was complete, the mixture was stirred and reacted at 50°C for 2 h, filtered, washed with deionized water, and vacuum dried at 80°C for 4 h to obtain flame-retardant particles, designated TiO2-Al2O3@Mg(OH)2.

[0117] S3. Modifying the photothermal agent on the flame retardant particles:

[0118] S3-1. Add 5 g of flame retardant particles and 1225 mg of ferric citrate to 100 mL of deionized water at 70° C. and ultrasonically disperse for 30 min to obtain mixed solution 1. Add 900 mg of glucose, 407 mg of 2',7'-dichlorodihydrofluorescein diacetate, 244 mg of 4-dimethylaminopyridine, and 465 mg of indocyanine green to a mixed solvent consisting of 40 mL of ethanol and 60 mL of deionized water and stir for 15 min to obtain mixed solution 2.

[0119] S3-2, adding the mixed solution 2 to the mixed solution 1 under stirring, ultrasonically dispersing at 70°C for 10 min to obtain a precursor solution, transferring the precursor solution into a polytetrafluoroethylene-lined reactor, reacting at 175°C for 8 h, cooling to room temperature, filtering, washing the solid product with ethanol, and vacuum drying at 90°C for 12 h to obtain functionalized flame retardant particles, recorded as TiO2-Al2O3@Mg(OH)2@Fe-CDs;

[0120] S4. Loading additives on functionalized flame retardant particles:

[0121] S4-1, adding an antioxidant and a UV absorber to acetone, stirring evenly, to prepare an additive impregnation solution having an antioxidant concentration of 10 g / L and a UV absorber concentration of 6 g / L;

[0122] The antioxidant is antioxidant 1010, and the ultraviolet absorber is ultraviolet absorber UV-9 (2-hydroxy-4-methoxybenzophenone);

[0123] S4-2. 5 g of functionalized flame-retardant particles were added to 100 mL of the impregnation solution, ultrasonically dispersed for 1 h, and then placed in a high-gravity packed bed (i.e., a rotating packed bed). After being treated under high-gravity conditions of 150 times the acceleration of gravity for 4 h, the particles were removed from the high-gravity packed bed, allowed to stand for 2 h, filtered, washed with acetone and ethanol in sequence, and vacuum-dried at 60°C for 12 h to obtain core particles.

[0124] S5. Coating the core particles with a polyurethane microporous membrane:

[0125] S5-1. Add 5 g of PPG (polypropylene glycol), 3.5 g of TDI (toluene diisocyanate), and 1.4 g of hydroxypropyl silicone oil to 100 mL of acetone. Heat the mixture to 65°C under nitrogen protection. Then, dropwise add 0.015 g of triethylenediamine. Stir and react for 1.5 h. Add 2 mL of butanediol and 0.8 mL of ethylenediamine. Stir and react at 72°C for 3 h. Cool the mixture to room temperature and remove the acetone by vacuum distillation to obtain a modified polyurethane emulsion.

[0126] S5-2. Take 5g of modified polyurethane emulsion, 2.5g of core particles, and 0.56g of polyethylene glycol, add them to a mixed solution consisting of 30mL of butanone and 30mL of DMF (N,N-dimethylformamide), stir for 15min, react with stirring at 70℃ for 30min, let it stand for 15min, cool to room temperature and then centrifuge. The obtained solid product is added to 50mL of DMF, stirred for 10min, filtered, and the solid product is added to 100mL of deionized water at 75℃, stirred for 4h, filtered, and the solid product is vacuum dried at 50℃ for 12h to obtain core-shell flame retardant and anti-UV particles.

[0127] Example 2

[0128] A highly flame-retardant, UV-resistant polyester fiber, the raw materials for its preparation comprising the following components by weight: 100 parts of polyester chips, 42 parts of core-shell flame-retardant UV-resistant particles, and 3 parts of an anti-dripping agent; the anti-dripping agent is triallyl isocyanurate;

[0129] The preparation method of the polyester fiber comprises the following steps:

[0130] 1) The polyester chips were vacuum dried at 110° C. for 12 h, and then stirred and mixed with the core-shell flame retardant and anti-UV particles and the anti-dripping agent at 500 rpm for 30 min to obtain a polyester blend;

[0131] 2) adding the polyester mixture into a twin-screw extruder and melt-extruded at 240° C., and spinning the resulting melt to obtain a UV-resistant and highly flame-retardant polyester fiber; wherein the spinning temperature is 265° C., the spinning speed is 750 m / min, the draft ratio is 2 times, and the stretching rate is 700 m / min.

[0132] The core-shell flame retardant and anti-ultraviolet particles are prepared by the following method:

[0133] S1. Preparation of porous carrier:

[0134] 1.7 mL of tetrabutyl titanate was added to 50 mL of n-butanol and stirred for 5 min to obtain solution A. 10 g of Al(NO3)3·9H2O and 0.25 g of hexadecyltrimethylammonium bromide were added to 150 mL of deionized water and stirred for 10 min, followed by 7.9 g of ammonium bicarbonate. After stirring for 30 min, solution A was added and ultrasonic dispersion was performed for 1 h. The resulting mixture was added to a reactor and reacted at 160°C for 12 h. The mixture was cooled to room temperature, filtered, washed, vacuum dried at 90°C for 6 h, calcined at 700°C for 4 h, and ground to obtain a porous support, which was designated as TiO2-Al2O3.

[0135] S2. Loading magnesium hydroxide on a porous carrier:

[0136] 5 g of the porous support was added to 200 mL of deionized water and ultrasonically dispersed for 30 min. 3.15 g of MgCl2 was then added and stirred for 15 min. 75 mL of a 1 mol / L aqueous NaOH solution was then added dropwise with stirring. After the addition was complete, the mixture was stirred and reacted at 50°C for 2 h, filtered, washed with deionized water, and vacuum dried at 80°C for 4 h to obtain flame-retardant particles, designated TiO2-Al2O3@Mg(OH)2.

[0137] S3. Modifying the photothermal agent on the flame retardant particles:

[0138] S3-1. Add 5 g of flame retardant particles and 1225 mg of ferric citrate to 100 mL of deionized water at 70° C. and ultrasonically disperse for 30 min to obtain mixed solution 1. Add 900 mg of glucose, 407 mg of 2',7'-dichlorodihydrofluorescein diacetate, 244 mg of 4-dimethylaminopyridine, and 465 mg of indocyanine green to a mixed solvent consisting of 40 mL of ethanol and 60 mL of deionized water and stir for 15 min to obtain mixed solution 2.

[0139] S3-2, adding the mixed solution 2 to the mixed solution 1 under stirring, ultrasonically dispersing at 70°C for 10 min to obtain a precursor solution, transferring the precursor solution into a polytetrafluoroethylene-lined reactor, reacting at 175°C for 8 h, cooling to room temperature, filtering, washing the solid product with ethanol, and vacuum drying at 90°C for 12 h to obtain functionalized flame retardant particles, recorded as TiO2-Al2O3@Mg(OH)2@Fe-CDs;

[0140] S4. Loading additives on functionalized flame retardant particles:

[0141] S4-1, adding an antioxidant and a UV absorber to acetone, stirring evenly, to prepare an additive impregnation solution having an antioxidant concentration of 10 g / L and a UV absorber concentration of 6 g / L;

[0142] The antioxidant is antioxidant 1010, and the ultraviolet absorber is ultraviolet absorber UV-9 (2-hydroxy-4-methoxybenzophenone);

[0143] S4-2. 5 g of functionalized flame-retardant particles were added to 100 mL of the impregnation solution, ultrasonically dispersed for 1 h, and then placed in a high-gravity packed bed (i.e., a rotating packed bed). After being treated under high-gravity conditions of 150 times the acceleration of gravity for 4 h, the particles were removed from the high-gravity packed bed, allowed to stand for 2 h, filtered, washed with acetone and ethanol in sequence, and vacuum-dried at 60°C for 12 h to obtain core particles.

[0144] S5. Coating the core particles with a polyurethane microporous membrane:

[0145] S5-1. Add 5 g of PPG (polypropylene glycol), 3.5 g of TDI (toluene diisocyanate), and 1.4 g of hydroxypropyl silicone oil to 100 mL of acetone. Heat the mixture to 65°C under nitrogen protection. Then, dropwise add 0.015 g of triethylenediamine. Stir and react for 1.5 h. Add 2 mL of butanediol and 0.8 mL of ethylenediamine. Stir and react at 72°C for 3 h. Cool the mixture to room temperature and remove the acetone by vacuum distillation to obtain a modified polyurethane emulsion.

[0146] S5-2. Take 5g of modified polyurethane emulsion, 2.5g of core particles, and 0.85g of polyethylene glycol, add them to a mixed solution consisting of 30mL of butanone and 30mL of DMF (N,N-dimethylformamide), stir for 15min, react with stirring at 70℃ for 30min, let it stand for 15min, cool to room temperature and then centrifuge. The obtained solid product is added to 50mL of DMF, stirred for 10min, filtered, and the solid product is added to 100mL of deionized water at 75℃, stirred for 4h, filtered, and the solid product is vacuum dried at 50℃ for 12h to obtain core-shell flame retardant and anti-UV particles.

[0147] Example 3

[0148] A highly flame-retardant, UV-resistant polyester fiber, the raw materials for its preparation comprising the following components by weight: 100 parts of polyester chips, 42 parts of core-shell flame-retardant UV-resistant particles, and 3 parts of an anti-dripping agent; the anti-dripping agent is triallyl isocyanurate;

[0149] The preparation method of the polyester fiber comprises the following steps:

[0150] 1) The polyester chips were vacuum dried at 110° C. for 12 h, and then stirred and mixed with the core-shell flame retardant and anti-UV particles and the anti-dripping agent at 500 rpm for 30 min to obtain a polyester blend;

[0151] 2) adding the polyester mixture into a twin-screw extruder and melt-extruded at 240° C., and spinning the resulting melt to obtain a UV-resistant and highly flame-retardant polyester fiber; wherein the spinning temperature is 265° C., the spinning speed is 750 m / min, the draft ratio is 2 times, and the stretching rate is 700 m / min.

[0152] The core-shell flame retardant and anti-ultraviolet particles are prepared by the following method:

[0153] S1. Preparation of porous carrier:

[0154] 1.7 mL of tetrabutyl titanate was added to 50 mL of n-butanol and stirred for 5 min to obtain solution A. 10 g of Al(NO3)3·9H2O and 0.25 g of hexadecyltrimethylammonium bromide were added to 150 mL of deionized water and stirred for 10 min, followed by 7.9 g of ammonium bicarbonate. After stirring for 30 min, solution A was added and ultrasonic dispersion was performed for 1 h. The resulting mixture was added to a reactor and reacted at 160°C for 12 h. The mixture was cooled to room temperature, filtered, washed, vacuum dried at 90°C for 6 h, calcined at 700°C for 4 h, and ground to obtain a porous support, which was designated as TiO2-Al2O3.

[0155] S2. Loading magnesium hydroxide on a porous carrier:

[0156] 5 g of the porous support was added to 200 mL of deionized water and ultrasonically dispersed for 30 min. 3.15 g of MgCl2 was then added and stirred for 15 min. 75 mL of a 1 mol / L aqueous NaOH solution was then added dropwise with stirring. After the addition was complete, the mixture was stirred and reacted at 50°C for 2 h, filtered, washed with deionized water, and vacuum dried at 80°C for 4 h to obtain flame-retardant particles, designated TiO2-Al2O3@Mg(OH)2.

[0157] S3. Modifying the photothermal agent on the flame retardant particles:

[0158] S3-1. Add 5 g of flame retardant particles and 1225 mg of ferric citrate to 100 mL of deionized water at 70° C. and ultrasonically disperse for 30 min to obtain mixed solution 1. Add 900 mg of glucose, 407 mg of 2',7'-dichlorodihydrofluorescein diacetate, 244 mg of 4-dimethylaminopyridine, and 465 mg of indocyanine green to a mixed solvent consisting of 40 mL of ethanol and 60 mL of deionized water and stir for 15 min to obtain mixed solution 2.

[0159] S3-2, adding the mixed solution 2 to the mixed solution 1 under stirring, ultrasonically dispersing at 70°C for 10 min to obtain a precursor solution, transferring the precursor solution into a polytetrafluoroethylene-lined reactor, reacting at 175°C for 8 h, cooling to room temperature, filtering, washing the solid product with ethanol, and vacuum drying at 90°C for 12 h to obtain functionalized flame retardant particles, recorded as TiO2-Al2O3@Mg(OH)2@Fe-CDs;

[0160] S4. Loading additives on functionalized flame retardant particles:

[0161] S4-1, adding an antioxidant and a UV absorber to acetone, stirring evenly, to prepare an additive impregnation solution having an antioxidant concentration of 10 g / L and a UV absorber concentration of 6 g / L;

[0162] The antioxidant is antioxidant 1010, and the ultraviolet absorber is ultraviolet absorber UV-9 (2-hydroxy-4-methoxybenzophenone);

[0163] S4-2. 5 g of functionalized flame-retardant particles were added to 100 mL of the impregnation solution, ultrasonically dispersed for 1 h, and then placed in a high-gravity packed bed (i.e., a rotating packed bed). After being treated under high-gravity conditions of 150 times the acceleration of gravity for 4 h, the particles were removed from the high-gravity packed bed, allowed to stand for 2 h, filtered, washed with acetone and ethanol in sequence, and vacuum-dried at 60°C for 12 h to obtain core particles.

[0164] S5. Coating the core particles with a polyurethane microporous membrane:

[0165] S5-1. Add 5 g of PPG (polypropylene glycol), 3.5 g of TDI (toluene diisocyanate), and 1.4 g of hydroxypropyl silicone oil to 100 mL of acetone. Heat the mixture to 65°C under nitrogen protection. Then, dropwise add 0.015 g of triethylenediamine. Stir and react for 1.5 h. Add 2 mL of butanediol and 0.8 mL of ethylenediamine. Stir and react at 72°C for 3 h. Cool the mixture to room temperature and remove the acetone by vacuum distillation to obtain a modified polyurethane emulsion.

[0166] S5-2. Take 5g of modified polyurethane emulsion, 2.5g of core particles, and 1.0g of polyethylene glycol, add them to a mixed solution consisting of 30mL of butanone and 30mL of DMF (N,N-dimethylformamide), stir for 15min, react with stirring at 70℃ for 30min, let it stand for 15min, cool to room temperature and then centrifuge. The obtained solid product is added to 50mL of DMF, stirred for 10min, filtered, and the solid product is added to 100mL of deionized water at 75℃, stirred for 4h, filtered, and the solid product is vacuum dried at 50℃ for 12h to obtain core-shell flame retardant and anti-UV particles.

[0167] Example 4

[0168] A highly flame-retardant, UV-resistant polyester fiber, the raw materials for its preparation comprising the following components by weight: 100 parts of polyester chips, 42 parts of core-shell flame-retardant UV-resistant particles, and 3 parts of an anti-dripping agent; the anti-dripping agent is triallyl isocyanurate;

[0169] The preparation method of the polyester fiber comprises the following steps:

[0170] 1) The polyester chips were vacuum dried at 110° C. for 12 h, and then stirred and mixed with the core-shell flame retardant and anti-UV particles and the anti-dripping agent at 600 rpm for 25 min to obtain a polyester blend;

[0171] 2) adding the polyester mixture into a twin-screw extruder and melt-extruded at 245° C., and spinning the resulting melt to obtain a UV-resistant and highly flame-retardant polyester fiber; wherein the spinning temperature is 265° C., the spinning speed is 700 m / min, the draft ratio is 2 times, and the stretching rate is 700 m / min.

[0172] The core-shell flame retardant and anti-ultraviolet particles are prepared by the following method:

[0173] S1. Preparation of porous carrier:

[0174] 1.7 mL of tetrabutyl titanate was added to 50 mL of n-butanol and stirred for 5 min to obtain solution A. 10 g of Al(NO3)3·9H2O and 0.25 g of hexadecyltrimethylammonium bromide were added to 150 mL of deionized water and stirred for 10 min, followed by 7.9 g of ammonium bicarbonate. After stirring for 30 min, solution A was added and ultrasonic dispersion was performed for 1 h. The resulting mixture was added to a reactor and reacted at 160°C for 12 h. The mixture was cooled to room temperature, filtered, washed, vacuum dried at 90°C for 6 h, calcined at 700°C for 4 h, and ground to obtain a porous support, which was designated as TiO2-Al2O3.

[0175] S2. Loading magnesium hydroxide on a porous carrier:

[0176] 5 g of the porous support was added to 200 mL of deionized water and ultrasonically dispersed for 30 min. 3.15 g of MgCl2 was then added and stirred for 15 min. 75 mL of a 1 mol / L aqueous NaOH solution was then added dropwise with stirring. After the addition was complete, the mixture was stirred and reacted at 50°C for 2 h, filtered, washed with deionized water, and vacuum dried at 80°C for 4 h to obtain flame-retardant particles, designated TiO2-Al2O3@Mg(OH)2.

[0177] S3. Modifying the photothermal agent on the flame retardant particles:

[0178] S3-1. Add 5 g of flame retardant particles and 1225 mg of ferric citrate to 100 mL of deionized water at 70° C. and ultrasonically disperse for 30 min to obtain mixed solution 1. Add 900 mg of glucose, 407 mg of 2',7'-dichlorodihydrofluorescein diacetate, 244 mg of 4-dimethylaminopyridine, and 465 mg of indocyanine green to a mixed solvent consisting of 40 mL of ethanol and 60 mL of deionized water and stir for 15 min to obtain mixed solution 2.

[0179] S3-2, adding the mixed solution 2 to the mixed solution 1 under stirring, ultrasonically dispersing at 70°C for 10 min to obtain a precursor solution, transferring the precursor solution into a polytetrafluoroethylene-lined reactor, reacting at 175°C for 8 h, cooling to room temperature, filtering, washing the solid product with ethanol, and vacuum drying at 90°C for 12 h to obtain functionalized flame retardant particles, recorded as TiO2-Al2O3@Mg(OH)2@Fe-CDs;

[0180] S4. Loading additives on functionalized flame retardant particles:

[0181] S4-1, adding an antioxidant and a UV absorber to acetone, stirring evenly, to prepare an additive impregnation solution having an antioxidant concentration of 10 g / L and a UV absorber concentration of 6 g / L;

[0182] The antioxidant is antioxidant 1010, and the ultraviolet absorber is ultraviolet absorber UV-9 (2-hydroxy-4-methoxybenzophenone);

[0183] S4-2. 5 g of functionalized flame-retardant particles were added to 100 mL of the impregnation solution, ultrasonically dispersed for 1 h, and then placed in a high-gravity packed bed (i.e., a rotating packed bed). After being treated under high-gravity conditions of 100 times the acceleration of gravity for 5 h, the particles were removed from the high-gravity packed bed, allowed to stand for 2 h, filtered, washed with acetone and ethanol in sequence, and vacuum-dried at 60°C for 12 h to obtain core particles.

[0184] S5. Coating the core particles with a polyurethane microporous membrane:

[0185] S5-1. Add 5 g of PPG (polypropylene glycol), 3.5 g of TDI (toluene diisocyanate), and 1.4 g of hydroxypropyl silicone oil to 100 mL of acetone. Heat to 68°C under nitrogen protection. Then, dropwise add 0.015 g of triethylenediamine. Stir and react for 1.5 h. Add 2 mL of butanediol and 0.8 mL of ethylenediamine. Stir and react at 75°C for 3 h. Cool to room temperature. Remove acetone by vacuum distillation to obtain a modified polyurethane emulsion.

[0186] S5-2. Take 5g of modified polyurethane emulsion, 2.5g of core particles, and 0.56g of polyethylene glycol, add them to a mixed solution consisting of 30mL of butanone and 30mL of DMF (N,N-dimethylformamide), stir for 15min, react with stirring at 72°C for 30min, let it stand for 15min, cool to room temperature and then centrifuge. The obtained solid product is added to 50mL of DMF, stirred for 10min, filtered, and the solid product is added to 100mL of deionized water at 75°C, stirred for 4h, filtered, and the solid product is vacuum dried at 50°C for 12h to obtain core-shell flame retardant and anti-UV particles.

[0187] Comparative Example 1

[0188] The difference between this comparative example and Example 1 is that:

[0189] The core-shell flame retardant and anti-ultraviolet particles are prepared by the following method:

[0190] S1. Prepare a porous carrier, the steps are the same as in Example 1;

[0191] S2. Loading magnesium hydroxide on a porous carrier to prepare flame-retardant particles, the steps are the same as those in Example 1;

[0192] S3. Loading additives on flame retardant particles:

[0193] S3-1, adding an antioxidant and a UV absorber to acetone, stirring evenly, to prepare an additive impregnation solution with an antioxidant concentration of 10 g / L and a UV absorber concentration of 6 g / L;

[0194] The antioxidant is antioxidant 1010, and the ultraviolet absorber is ultraviolet absorber UV-9 (2-hydroxy-4-methoxybenzophenone);

[0195] S3-2. 5 g of flame-retardant particles were added to 100 mL of the impregnation solution, ultrasonically dispersed for 1 hour, and then placed in a high-gravity packed bed (i.e., a rotating packed bed). After being treated under high-gravity conditions of 150 times the acceleration of gravity for 4 hours, the particles were removed from the high-gravity packed bed, allowed to stand for 2 hours, filtered, washed with acetone and ethanol in sequence, and vacuum-dried at 60°C for 12 hours to obtain core particles.

[0196] S4. Coating the core particles with a polyurethane microporous membrane, the steps are the same as those in Example 1.

[0197] Comparative Example 2

[0198] The only difference between this comparative example and Example 1 is that ferric citrate is not added in step S3-1.

[0199] Comparative Example 3

[0200] The only difference between this comparative example and Example 1 is that indocyanine green is not added in step S3-1.

[0201] Comparative Example 4

[0202] The difference between this comparative example and Example 1 is that:

[0203] Step S1 of preparing core-shell flame retardant and anti-ultraviolet particles is:

[0204] Take 10g AI(NO3)3·9H2O and 0.25g hexadecyltrimethylammonium bromide and add them to 150mL deionized water. After stirring for 10min, add 7.9g ammonium bicarbonate. After stirring for 30min, add 50mL n-butanol and ultrasonically disperse for 1h. The resulting mixture is added to a reactor, reacted at 160℃ for 12h, cooled to room temperature, filtered, washed, vacuum dried at 90℃ for 6h, calcined at 700℃ for 4h, and ground to obtain a porous carrier.

[0205] Comparative Example 5

[0206] A UV-resistant and highly flame-retardant polyester fiber, wherein the raw materials for preparing the polyester fiber include the following components by weight: 100 parts of polyester chips, 39 parts of core-shell UV-resistant particles, 3 parts of magnesium hydroxide, and 3 parts of an anti-dripping agent; the anti-dripping agent is triallyl isocyanurate. The preparation method of the polyester fiber comprises the following steps:

[0207] 1) The polyester chips were vacuum dried at 110° C. for 12 hours, and then stirred and mixed with core-shell anti-UV particles, magnesium hydroxide, and an anti-dripping agent at 600 rpm for 25 minutes to obtain a polyester mixture;

[0208] 2) adding the polyester mixture into a twin-screw extruder and melt-extruded at 245° C., and spinning the resulting melt to obtain a UV-resistant and highly flame-retardant polyester fiber; wherein the spinning temperature is 265° C., the spinning speed is 700 m / min, the draft ratio is 2 times, and the stretching rate is 700 m / min.

[0209] The core-shell anti-ultraviolet particles are prepared by the following method:

[0210] S1. Prepare a porous carrier, the steps are the same as in Example 1;

[0211] S2. Modifying the photothermal agent on the porous carrier:

[0212] S2-1. Add 5 g of the porous carrier and 1225 mg of ferric citrate to 100 mL of deionized water at 70°C, and ultrasonically disperse for 30 min to obtain a mixed solution 1. Add 900 mg of glucose, 407 mg of 2',7'-dichlorodihydrofluorescein diacetate, 244 mg of 4-dimethylaminopyridine, and 465 mg of indocyanine green to a mixed solvent consisting of 40 mL of ethanol and 60 mL of deionized water, and stir for 15 min to obtain a mixed solution 2.

[0213] S2-2, adding mixed solution 2 to mixed solution 1 under stirring, ultrasonically dispersing at 70°C for 10 min to obtain a precursor solution, transferring the precursor solution into a polytetrafluoroethylene-lined reactor, reacting at 175°C for 8 h, cooling to room temperature, filtering, washing the solid product with ethanol, and vacuum drying at 90°C for 12 h to obtain functionalized particles;

[0214] S3. Loading additives on functionalized particles:

[0215] S3-1. Add an antioxidant and a UV absorber to acetone and stir evenly to prepare an additive impregnation solution having an antioxidant concentration of 10 g / L and a UV absorber concentration of 6 g / L; wherein the antioxidant is antioxidant 1010 and the UV absorber is UV-9 (2-hydroxy-4-methoxybenzophenone);

[0216] S3-2. 5 g of functionalized particles were added to 100 mL of impregnation solution, ultrasonically dispersed for 1 h, and then placed in a high-gravity packed bed (i.e., a rotating packed bed). After treatment under high-gravity conditions of 150 times the acceleration of gravity for 4 h, the particles were removed from the high-gravity packed bed, allowed to stand for 2 h, filtered, washed with acetone and ethanol in sequence, and vacuum dried at 60°C for 12 h to obtain core particles.

[0217] S4. Coating the core particles with a polyurethane microporous membrane to obtain core-shell anti-ultraviolet particles. The steps are the same as those in Example 1.

[0218] Comparative Example 6

[0219] A UV-resistant, highly flame-retardant polyester fiber, the raw materials for its preparation comprising the following components by weight: 100 parts polyester chips, 42 parts core particles, and 3 parts anti-drip agent; the anti-drip agent is triallyl isocyanurate. The preparation method of the polyester fiber comprises the following steps:

[0220] 1) The polyester chips were vacuum dried at 110° C. for 12 h, and then stirred with the core particles and the anti-drip agent at 600 rpm for 25 min to obtain a polyester blend;

[0221] 2) adding the polyester mixture into a twin-screw extruder and melt-extruded at 245° C., and spinning the resulting melt to obtain a UV-resistant and highly flame-retardant polyester fiber; wherein the spinning temperature is 265° C., the spinning speed is 700 m / min, the draft ratio is 2 times, and the stretching rate is 700 m / min.

[0222] The preparation method of the core particles is the same as that in Example 1.

[0223] 1. Performance Characterization

[0224] 1. Reference Figure 1 , is the infrared absorption spectrum of the porous support (TiO2-Al2O3) and functionalized flame retardant particles [TiO2-Al2O3@Mg(OH)2@Fe-CDs] prepared in Example 1. It can be seen that Mg(OH)2 and Fe-CDs are successfully loaded on TiO2-Al2O3.

[0225] 2. Photothermal performance

[0226] 2-1. Add functionalized flame retardant particles and deionized water into a container and ultrasonically disperse for 20 minutes to prepare a dispersion with a concentration of 1.0 mg / mL. Irradiate the dispersion with a 350nm ultraviolet light source for 10 minutes (the light source is located directly above the dispersion, 10 cm away from the dispersion), and control the light source power density to 1.0 W / cm 2 , the ambient temperature is 25℃, use an infrared thermal imager, record the temperature once every 1 minute, and draw a temperature-time curve.

[0227] Reference Figure 2 The temperature-time curves for the flame-retardant particles [TiO2-Al2O3@Mg(OH)2] and the functionalized flame-retardant particles [TiO2-Al2O3@Mg(OH)2@Fe-CDs] prepared in Example 1 show that TiO2-Al2O3@Mg(OH)2@Fe-CDs exhibits significant photothermal performance, while TiO2-Al2O3@Mg(OH)2 lacks it. This comparison demonstrates that the photothermal performance stems from the modified carbon dots (Fe-CDs). Further testing revealed that when UV light was continuously applied for 12 hours, the temperature stabilized after reaching approximately 84°C and remained essentially stationary. This was primarily due to limitations in light source power, the balance between heat generation and dissipation, and the photothermal efficiency of the functionalized flame-retardant particles. This suggests that the temperature generated by photothermal treatment has an upper limit and does not continue to rise. In order to further test the photothermal effect of the core-shell flame retardant and anti-ultraviolet particles added to the polyester fiber, the polyester fiber prepared in Example 1 was tested under a 350nm ultraviolet light source (control light source power density 1.0W / cm 2, 50 cm away from the polyester fiber) after continuous irradiation for 12 hours, the local maximum temperature in the polyester fiber was 89°C; on the basis of Example 1, the addition amount of the core-shell type flame retardant and anti-UV particles was adjusted to 20 parts and 60 parts, and the maximum temperatures obtained by the test were 76°C and 97°C respectively, indicating that after being added to the polyester fiber, the prepared polyester fiber also exhibited photothermal properties, and the temperature caused by photothermal also has an upper limit and will not continue to rise.

[0228] 2-2. The core-shell flame retardant and anti-ultraviolet particles in Example 1-4 and Comparative Example 2-3 were added to a container and prepared into a dispersion with a concentration of 1.0 mg / mL using deionized water. The dispersion was irradiated with a 350 nm ultraviolet light source for 10 min (the light source was located directly above the dispersion, with a distance of 10 cm from the dispersion). The light source power density was controlled at 1.0 W / cm 2 , use an infrared thermal imager to detect the temperature of the system, and calculate the photothermal conversion efficiency η (%) according to the literature "Lv Ju, Pan Lang, Qiu Yuheng, et al. Preparation, characterization and performance of photothermal and photodynamic synergistic antibacterial carbon dots [J]. Fine Chemicals, 2024, 41(8):1745-1753." according to the following formula:

[0229] ;

[0230] Where: h is the heat transfer coefficient, unit W / (m 2 ·K); S is the surface area of ​​the container, unit is m 2 ;T m is the maximum steady-state temperature, unit K; T r is the ambient room temperature, unit K; Q0 is the reference energy input of deionized water and container without adding functionalized flame retardant particles, unit J; P is the light source power, unit W; A 350 is the absorbance of the dispersion at 350 nm.

[0231] The photothermal conversion efficiency test results are shown in Table 1 below:

[0232] Table 1

[0233] Example 1 Example 2 Example 3 Example 4 Comparative Example 2 Comparative Example 3 Photothermal conversion efficiency η (%) 38.1 40.6 42.0 37.7 31.6 30.3

[0234] The results of Examples 1-3 show that increasing the porogen polyethylene glycol content leads to a modest increase in the photothermal conversion efficiency of the core-shell flame-retardant, UV-resistant particles. This increase is attributed to the increased porosity of the polyurethane microporous membrane. Comparison of Comparative Examples 2-3 with Example 1 demonstrates that both Fe doping of the photothermal agent (carbon dots) and the addition of indocyanine green can improve photothermal conversion efficiency.

[0235] 3. Ultraviolet absorption performance

[0236] Reference Figure 4 The ultraviolet-visible absorption spectra of the core-shell flame retardant and anti-UV particles prepared in Example 1, Comparative Example 1 and Comparative Example 4 show that Example 1 has a very wide ultraviolet absorption region, and the ultraviolet absorption capabilities of Comparative Example 1 and Comparative Example 4 are significantly reduced, indicating that the photothermal agent and TiO2 in the core-shell flame retardant and anti-UV particles can both improve the ultraviolet absorption performance.

[0237] 4. UV absorber release performance

[0238] Test method: Take 10g of the core-shell flame retardant and anti-ultraviolet particles prepared in Example 1, wrap them in a filter bag and place them in a glass container. Perform the following operations every 12 hours:

[0239] (1) Dark group (No Light): Add 50 mL of acetone and soak for 60 min, then rinse with acetone three times, take out, collect the rinse liquid and soaking liquid, combine them, measure the total volume of the liquid, and use gas chromatography to detect the concentration of ultraviolet absorber UV-9 in it to obtain the release amount;

[0240] (2) Illumination group (350nm Light): Add 50mL of acetone and irradiate at 350nm (the light source is located 20cm above, with a power density of 1.0W / cm 2 ) for 60 min, then rinse with acetone three times, take out, collect the rinse liquid and soaking liquid, combine them, measure the total volume of the liquid, and use gas chromatography to detect the concentration of ultraviolet absorber UV-9 therein to obtain the release amount;

[0241] The two groups were tested for 180 hours respectively, and the release curve was drawn with the accumulated release percentage (Accumulated Release) as the vertical axis and the treatment time as the horizontal axis. , Q t represents the cumulative release amount within time t, Q0 represents the total loading amount of the ultraviolet absorber UV-9, and Q0 can be obtained by subtracting the mass of the ultraviolet absorber UV-9 remaining in the auxiliary agent impregnation solution after impregnation from the total mass of the ultraviolet absorber UV-9 in acetone in step S4-1 of Example 1.

[0242] The test results are as follows Figure 5 As shown, it can be seen that both groups showed good sustained-release performance, and the release of ultraviolet absorber UV-9 was significantly increased after increasing the light exposure, indicating that the core-shell flame retardant anti-UV particles can promote the release of the ultraviolet absorber under ultraviolet light, verifying its "adaptive regulation" performance.

[0243] 2. Application Performance Testing

[0244] The polyester fibers prepared in Examples 1-4 and Comparative Examples 1-6 were subjected to the following performance tests:

[0245] 1. Anti-ultraviolet performance

[0246] The UV transmittance was tested according to the standard GB / T18830-2009. The test results are shown in Table 2 and Figure 6 、 Figure 7 As shown:

[0247] Table 2

[0248] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 UVA transmittance / % 0.45 0.42 0.38 0.47 18.2 2.5 3.1 9.7 0.48 5.7 UVB transmittance / % 0.16 0.14 0.11 0.19 4.7 0.46 0.58 2.5 0.20 0.92

[0249] The test results show that Examples 1-4 have excellent anti-UV performance. The increased porogen content in Examples 2 and 3 increases the exposure of the anti-UV active ingredients, which enhances the anti-UV performance to a certain extent. The unmodified carbon dots in the core-shell flame-retardant anti-UV particles of Comparative Example 1 significantly reduce the anti-UV performance. The results of Comparative Examples 2 and 3 show that the doping of Fe in the carbon dots and the addition of indocyanine green can both improve the anti-UV performance. The lack of TiO2 in Comparative Example 4 leads to a significant decrease in the anti-UV performance. The anti-UV performance of Comparative Example 5 remains unchanged. The lack of polyurethane microporous membrane coating in Comparative Example 6 makes it difficult to evenly disperse the core particles, affecting the performance of the active components and significantly reducing the anti-UV performance.

[0250] 2. Flame retardant properties

[0251] Refer to the GB / T 2406.2-2009 test, the test results are shown in Table 3 and Figure 8 As shown:

[0252] Table 3

[0253] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Limiting oxygen index (LOI) / % 39.4 38.7 38.2 39.1 38.2 39.1 39.3 38.6 30.3 30.9

[0254] 3. Breaking strength

[0255] The breaking strength of polyester fiber was measured with reference to the standard "GB / T 14344-2022 Test method for tensile properties of chemical fiber filaments". The test results are shown in Table 4 and Figure 9 As shown:

[0256] Table 4

[0257] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Breaking strength (cN / detx) 3.52 3.41 3.30 3.49 3.50 3.54 3.52 2.91 3.23 3.12

[0258] Test the breaking strength after aging: irradiate the polyester fiber with ultraviolet light of wavelength 350nm for 300h (the distance between the light source and the sample is 30cm, the power is 40W), then measure the breaking strength and calculate the breaking strength retention rate, breaking strength retention rate = (breaking strength after irradiation / breaking strength before irradiation) × 100%. The test results are shown in Table 5 and Figure 10 As shown:

[0259] Table 5

[0260] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Breaking strength retention rate (%) 96.8 96.1 95.5 96.3 84.2 90.6 88.7 90.5 95.7 89.4

[0261] From the test results, it can be seen that Examples 1-4 have excellent UV aging resistance, and Comparative Examples 1-4 and Comparative Example 6 have different degrees of decline in UV aging resistance.

[0262] Although embodiments of the present application have been disclosed as above, it is not limited to only the use listed in the specification and the embodiments, and can be applied to various fields suitable for the present application, and additional modifications can be easily made by those skilled in the art, and thus the present application is not limited to specific details, without departing from the general concept defined by the claims and the equivalent scope.

Claims

1. A UV-resistant and highly flame-retardant polyester fiber, characterized in that: The raw materials for its preparation include the following components by weight: 100 parts of polyester chips, 20-60 parts of core-shell flame retardant and anti-ultraviolet particles, and 2-4.5 parts of anti-dripping agent; the core-shell flame retardant and anti-ultraviolet particles are prepared by the following method: S1. preparing a porous support, wherein the porous support is a composite of porous alumina and titania; S2. Loading magnesium hydroxide on a porous carrier to obtain flame retardant particles; S3, modifying the flame retardant particles with a photothermal agent to obtain functionalized flame retardant particles, wherein the photothermal agent is a carbon dot with photothermal properties; S4, loading additives onto the functionalized flame retardant particles to obtain core particles, wherein the additives include an antioxidant and a UV absorber; S5. Coating the core particles with a polyurethane microporous membrane to obtain core-shell flame-retardant and anti-ultraviolet particles.

2. The UV-resistant and highly flame-retardant polyester fiber according to claim 1, characterized in that: The anti-dripping agent is at least one of melamine, benzoguanamine, and triallyl isocyanurate; the antioxidant is at least one of antioxidant 1010, antioxidant 618, antioxidant 1076, and antioxidant 1098; and the ultraviolet absorber is at least one of UV-P, UV-1, UV-9, UVBP-4, UV-234, and UVP-327.

3. The UV-resistant and highly flame-retardant polyester fiber according to claim 1, characterized in that: The core-shell flame retardant and anti-ultraviolet particles are prepared by the following method: S1. Preparation of a porous support: using tetrabutyl titanate as a titanium source, Al(NO3)3·9H2O as an aluminum source, hexadecyltrimethylammonium bromide as a template, and ammonium bicarbonate as a precipitant, to prepare a porous alumina and titania composite, i.e., a porous support, by hydrothermal reaction and calcination; S2, mixing and reacting a porous carrier, MgCl2, and NaOH, and loading magnesium hydroxide on the porous carrier to obtain flame retardant particles; S3. Loading magnesium hydroxide: Using glucose, ferric citrate, 2',7'-dichlorodihydrofluorescein diacetate, 4-dimethylaminopyridine, and indocyanine green as raw materials and a mixture of ethanol and water as solvent, carbon dots with photothermal properties were in situ synthesized on flame-retardant particles by a hydrothermal method to obtain functionalized flame-retardant particles. The carbon dots are the photothermal agent. S4. Loading additives: Loading additives on the functionalized flame retardant particles by using a high gravity assisted impregnation method to obtain core particles, wherein the additives include antioxidants and ultraviolet absorbers; S5. Coating with polyurethane microporous membrane: coating the inner core particles with polyurethane microporous membrane to obtain core-shell type flame retardant and anti-ultraviolet particles.

4. The UV-resistant and highly flame-retardant polyester fiber according to claim 3, characterized in that: Step S1 is specifically as follows: Tetrabutyl titanate is added to n-butanol to obtain liquid A, AI(NO3)3·9H2O and hexadecyltrimethylammonium bromide are added to deionized water, and then ammonium bicarbonate is added. After stirring, liquid A is added. The resulting mixture is added to a reactor, reacted at 150-170°C for 6-24 hours, and the solid product is calcined at 400-550°C for 2-8 hours to obtain a porous carrier.

5. The UV-resistant and highly flame-retardant polyester fiber according to claim 3, characterized in that: Step S2 is specifically as follows: disperse the porous carrier in deionized water, add MgCl2, dropwise add NaOH aqueous solution, stir and react at 40-60°C for 1-4h after the dropwise addition is completed, filter, wash and dry to obtain flame retardant particles.

6. The UV-resistant and highly flame-retardant polyester fiber according to claim 3, characterized in that: Step S3 is specifically as follows: S3-1, dispersing flame retardant particles and ferric citrate in deionized water at a temperature of 60-80° C. to obtain mixed solution 1; adding glucose, 2',7'-dichlorodihydrofluorescein diacetate, 4-dimethylaminopyridine and indocyanine green to a mixed solvent consisting of ethanol and deionized water, and stirring to obtain mixed solution 2; S3-2, adding mixed solution 2 to mixed solution 1, transferring the obtained precursor solution into a reactor, reacting at 165-190° C. for 4-16 hours, filtering, washing, and drying to obtain functionalized flame retardant particles.

7. The UV-resistant and highly flame-retardant polyester fiber according to claim 3, characterized in that: Step S4 is specifically as follows: S4-1, adding an antioxidant and a UV absorber to acetone to prepare an additive impregnation solution having an antioxidant concentration of 5-20 g / L and a UV absorber concentration of 3-12 g / L; S4-2. Add functionalized flame retardant particles to the impregnation solution, ultrasonically disperse for 0.5-2 hours, and then place them in a high-gravity packed bed. Treat them under high-gravity conditions of 25-100 times the acceleration of gravity for 2-8 hours, remove them, let them stand for 1-4 hours, filter, wash, and dry them to obtain core particles.

8. The UV-resistant and highly flame-retardant polyester fiber according to claim 3, characterized in that: Step S5 is specifically as follows: S5-1. PPG, TDI, and hydroxypropyl silicone oil are added to acetone, heated to 55-75°C, triethylenediamine is added dropwise, and the mixture is stirred for 1-3 hours. Butanediol and ethylenediamine are added, and the mixture is stirred at 70-75°C for 1.5-6 hours. Acetone is removed by vacuum distillation to obtain a modified polyurethane emulsion. S5-2. Take the modified polyurethane emulsion, core particles, and polyethylene glycol and add them to a mixed solution of butanone and DMF. Stir and react at 65-75°C for 15-60 minutes, let it stand for 5-30 minutes, and centrifuge. Add the obtained solid product to DMF, stir, and filter. Add the solid product to deionized water at a temperature of 70-80°C, stir for 2-8 hours, filter, and dry for 1 hour to obtain core-shell flame retardant and anti-UV particles.

9. The UV-resistant and highly flame-retardant polyester fiber according to claim 3, characterized in that: The core-shell flame retardant and anti-ultraviolet particles are prepared by the following method: S1. Preparation of porous carrier: 0.85-3.4 mL of tetrabutyl titanate was added to 25-100 mL of n-butanol and stirred for 2-10 min to obtain solution A; 5-20 g of AI(NO3)3·9H2O and 0.12-0.5 g of hexadecyltrimethylammonium bromide were added to 75-300 mL of deionized water and stirred for 5-20 min, followed by 4-16 g of ammonium bicarbonate and stirring for 15-60 min. Solution A was added and ultrasonic dispersion was performed for 0.5-2 h. The resulting mixture was added to a reactor and reacted at 150-170°C for 6-24 h. The mixture was cooled to room temperature, filtered, washed, dried, calcined at 650-750°C for 2-8 h, and ground to obtain a porous carrier; S2. Loading magnesium hydroxide on a porous carrier: Take 2.5-10g of the porous carrier and disperse it in 100-400mL of deionized water. Add 1.5-6.3g of MgCl2. Add 30-150mL of 1mol / L NaOH aqueous solution dropwise while stirring. Stir and react at 40-60℃ for 1-4h. Filter, wash, and dry to obtain flame-retardant particles. S3. Modifying the photothermal agent on the flame retardant particles: S3-1. Disperse 2.5-10 g of flame retardant particles and 612-2450 mg of ferric citrate in 50-200 mL of deionized water at 60-80° C. to obtain a mixed solution 1. Add 450-1800 mg of glucose, 200-814 mg of 2',7'-dichlorodihydrofluorescein diacetate, 122-488 mg of 4-dimethylaminopyridine, and 220-930 mg of indocyanine green to a mixed solvent consisting of 20-80 mL of ethanol and 30-120 mL of deionized water, and stir for 5-30 minutes to obtain a mixed solution 2. S3-2, adding the mixed solution 2 to the mixed solution 1 under stirring, ultrasonically dispersing at 60-80°C for 5-20 minutes, transferring the obtained precursor solution to a reaction kettle, reacting at 165-190°C for 4-16 hours, cooling, filtering, washing, and drying to obtain functionalized flame retardant particles; S4. Loading additives on functionalized flame retardant particles: S4-1, adding an antioxidant and a UV absorber to acetone, stirring evenly, to prepare an additive impregnation solution having an antioxidant concentration of 5-20 g / L and a UV absorber concentration of 3-12 g / L; S4-2, taking 2.5-10g of functionalized flame retardant particles, adding them to 50-200mL of impregnation solution, ultrasonically dispersing them for 0.5-2h, placing them in a high-gravity packed bed, treating them under high-gravity conditions of 100-400 times the acceleration of gravity for 2-8h, removing them, letting them stand for 1-4h, filtering, washing, and drying them to obtain core particles; S5. Coating the core particles with a polyurethane microporous membrane: S5-1. Add 2.5-10 g PPG, 1.75-7 g TDI, and 0.7-2.8 g hydroxypropyl silicone oil to 50-200 mL acetone, and heat to 55-75°C under nitrogen protection. Then, add 0.005-0.03 g triethylenediamine dropwise, and stir to react for 1-3 hours. Then, add 1-4 mL butanediol and 0.4-1.6 mL ethylenediamine, and stir to react at 70-75°C for 1.5-6 hours. Then, cool to room temperature, and remove acetone by vacuum distillation to obtain a modified polyurethane emulsion. S5-2. Take 2.5-10g of modified polyurethane emulsion, 1.25-5g of core particles, and 0.28-1.12g of polyethylene glycol, add them to a mixed solution consisting of 15-60mL of butanone and 15-60mL of DMF, stir for 5-30min, react with stirring at 65-75°C for 15-60min, let it stand for 5-30min, cool to room temperature and then centrifuge, add the obtained solid product to 25-100mL of DMF, stir for 5-20min, filter, add the solid product to 50-200mL of deionized water at a temperature of 70-80°C, stir for 2-8h, filter and dry to obtain core-shell flame retardant and anti-UV particles.

10. A method for preparing the UV-resistant and highly flame-retardant polyester fiber according to any one of claims 1 to 9, characterized in that: The following steps are involved: 1) The polyester chips are vacuum dried at 100-120° C. for 6-24 hours, and then stirred and mixed with core-shell flame retardant and anti-UV particles and an anti-dripping agent to obtain a polyester mixture; 2) Melting and extruding the polyester mixture at 230-245° C., spinning the resulting melt to obtain UV-resistant and highly flame-retardant polyester fibers at a spinning temperature of 250-270° C. and a spinning speed of 600-900 m / min.

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