An ultraviolet-resistant regenerated polyester fiber fabric and a preparation method thereof

Abstract

This invention discloses an anti-UV recycled polyester fiber fabric and its preparation method, belonging to the field of polyester fiber recycling technology. It addresses the technical problems of UV aging resistance, flame retardancy, abrasion resistance, and toughness in existing recycled polyester fiber fabrics. Specifically, it includes the following steps: polyester material is alcoholyzed and then repolymerized with alcohol to generate recycled polyester. This recycled polyester is then melt-blended with modified nano-zinc oxide, nano-structured titanium dioxide, a flame retardant, and auxiliary additives, followed by spinning. The recycled polyester fiber fabric is then prepared by weaving. This invention further improves the fabric's UV aging resistance, flame retardancy, abrasion resistance, and toughness through the synergistic effect of modified nano-zinc oxide, nano-structured titanium dioxide, and the flame retardant.

Description

Technical Field

[0001] This invention relates to the field of polyester fiber regeneration technology, specifically to a UV-resistant regenerated polyester fiber fabric and its preparation method. Background Technology

[0002] With the deepening of environmental protection concepts and the increasing demand for resource recycling, recycled polyester fiber fabrics, which are made from recycled polyester waste, are both environmentally friendly and economical, and are increasingly widely used in outdoor products, clothing, decorative materials and other fields. However, recycled polyester fiber fabrics made with traditional processes still need further improvement in terms of overall performance.

[0003] Currently, during the alcoholysis and regeneration process of recycled polyester materials, the molecular chains are prone to breakage, resulting in inherent deficiencies in the mechanical properties of recycled polyester. The breaking elongation and abrasion resistance of the fabric are generally lower than those of virgin polyester, and long-term use is prone to damage and deformation. At the same time, recycled polyester itself does not have UV protection properties, and most of them are improved by adding a single UV inhibitor. However, the UV inhibitor has poor dispersion in the fiber matrix and insufficient compatibility with the matrix, which not only leads to uneven UV protection effect, but also easily aggravates the brittleness of the fabric, making it difficult to achieve a synergistic improvement in UV aging resistance and mechanical properties. In addition, the flame retardant properties of recycled polyester fabrics mostly rely on the addition of traditional flame retardants. These flame retardants have weak interfacial bonding with the recycled polyester matrix and are prone to agglomeration and precipitation, which not only affects the flame retardant efficiency, but also further deteriorates the flexibility and abrasion resistance of the fabric.

[0004] To address this technical deficiency, a solution is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide an anti-ultraviolet recycled polyester fiber fabric and its preparation method, which solves the technical problems of anti-ultraviolet aging performance, flame retardant performance, abrasion resistance and toughness of recycled polyester fiber fabrics in the prior art.

[0006] The objective of this invention can be achieved through the following technical solution: a method for preparing a UV-resistant recycled polyester fiber fabric, comprising the following steps:

[0007] S1. The recycled polyester material is cleaned, disinfected, and then crushed. The crushed polyester material is then subjected to alcoholysis to obtain an alcoholysis extract.

[0008] S2. Add the alcoholysis extract, 1,4-butanediol and catalyst to the reactor, heat to 215-225℃ under nitrogen atmosphere, stir for 1-2 hours, then add polyethylene glycol and N,N'-Bis(2-hydroxyethyl)piperazine, stir for 20-30 minutes, evacuate the reaction system to a vacuum pressure of -0.1MPa, keep the reaction at this temperature for 1-2 hours, and wait until the stirring output power increases by 10-20% at a constant speed, then discharge the material to obtain recycled polyester.

[0009] Reaction mechanism:

[0010] During the reaction, the alcoholysis extract is a terephthalic acid ester unit. Under high temperature and the action of a catalyst, the ester bonds on the alcoholysis extract molecule undergo transesterification with the hydroxyl groups on the 1,4-butanediol molecule. The hydroxyl groups on the polyethylene glycol or N,N'-Bis(2-hydroxyethyl)piperazine molecule undergo transesterification with the alcoholysis extract or 1,4-butanediol terephthalic acid ester. The functional groups in the reaction system undergo esterification, introducing polyethylene glycol and N,N'-Bis(2-hydroxyethyl)piperazine blocks into it.

[0011] S3. After mixing recycled polyester, modified nano zinc oxide, nano-framework coated titanium dioxide, flame retardant and auxiliary additives, add it to a twin-screw extruder and hot-melt extrude it into a spinning machine. After melt spinning, stretching and impregnation, recycled polyester fiber is obtained.

[0012] S4. Add recycled polyester fibers to a weaving machine and weave them using a warp and weft weaving method to obtain recycled polyester fiber fabric.

[0013] Further, in step S2, the mass ratio of the alcoholysis extract, 1,4-butanediol, catalyst, polyethylene glycol, and N,N'-Bis(2-hydroxyethyl)piperazine is 100:12-14:0.12-0.15:8-10:3-5, and the catalyst is antimony trioxide; in step S3, the mass ratio of the recycled polyester, modified nano zinc oxide, nano-framework coated titanium dioxide, flame retardant, and auxiliary additives is 100:1.5-2.5:1-2:10-14:1-2, and the temperatures of the six temperature zones of the twin-screw extruder set from the feed end toward the die head are sequentially set to 250℃, 255℃, 260℃, 265℃, 260℃, and 255℃.

[0014] Furthermore, in step S3, the modified nano-zinc oxide is prepared by the following steps:

[0015] A1. Add red mud and hexadecyltrimethylammonium bromide to deionized water, stir at 70-80℃ for 1-2 hours, filter, wash the filter cake with deionized water 3-5 times, transfer it to a vacuum drying oven, and vacuum dry at 60℃ for 4 hours to obtain pretreated red mud.

[0016] A2. Mix the pretreated red mud and nano zinc oxide and add them to anhydrous ethanol. Stir at 20-30℃ for 20-30 min. Then add silane coupling agent solution dropwise. After the addition is complete, continue stirring for 1-2 h. After the reaction is complete, filter. Wash the filter cake with anhydrous ethanol 3-5 times and transfer it to a vacuum drying oven. Dry it at 100℃ to constant weight, grind it, and pass it through a 200-mesh sieve to obtain modified nano zinc oxide.

[0017] Reaction mechanism:

[0018] Because red mud contains hydroxyl groups, it exhibits a negative charge in aqueous solution. The hydrophilic end of the cationic surfactant hexadecyltrimethylammonium bromide reacts with the negative charge on the red mud surface through electrostatic adsorption and ion exchange, thereby displacing the Na+ adsorbed on the red mud surface. + Ca 2+ Impurity ions, with their hydrophobic long carbon chains, are oriented and arranged on the surface of red mud to complete organic modification, while preserving the porous structure of red mud. Anhydrous ethanol is used as a dispersion medium to reduce the interfacial tension between the pretreated red mud and nano-ZnO, so that the two are uniformly mixed. Nano-ZnO successfully attaches to the surface and pores of red mud through the physical adsorption of the porous structure of red mud. At the same time, the silane coupling agent KH-560 hydrolyzes to generate active Si-OH, which undergoes a dehydration condensation reaction with Zn-OH on the surface of nano-ZnO to form a stable chemical bond, chemically anchoring nano-ZnO to the porous surface of red mud, further enhancing the bonding stability of the two, and finally obtaining nano-ZnO.

[0019] Further, in step A1, the ratio of red mud, hexadecyltrimethylammonium bromide, and deionized water is 5-6g:0.01-0.02g:40mL; in step A2, the ratio of pretreated red mud, nano zinc oxide, anhydrous ethanol, and silane coupling agent solution is 10g:3g:45-50mL:8-10mL; the silane coupling agent solution is obtained by mixing KH-560 and deionized water at a volume ratio of 1:10 and stirring for 20-30 minutes.

[0020] Further, in step S3, the preparation of the nano-framework-coated titanium dioxide is as follows: modified nano-titanium dioxide is added to dimethylformyl and ultrasonically dispersed for 30-40 min. Then, the modified nano-framework is added and ultrasonically dispersed for another 40-50 min. The mixture is then heated to 70-80℃ and stirred for 24 h. After the reaction is complete, the mixture is filtered, and the filter cake is washed 3-5 times with anhydrous ethanol. Then, it is transferred to a vacuum drying oven and dried at 60℃ for 24 h. The mixture is then ground and passed through a 200-mesh sieve to obtain nano-framework-coated titanium dioxide. The ratio of the modified nano-titanium dioxide, dimethylformyl, and modified nano-framework is 0.1 g: 50-55 mL: 0.1 g.

[0021] Reaction mechanism:

[0022] First, the modified nano-titanium dioxide was ultrasonically dispersed in dimethylformamide to fully expose the perfluorooctyl hydrophobic chains grafted onto its surface. After adding the modified nano-framework, continuous ultrasonication was performed. The long-chain alkyl hydrophobic groups formed by the dodecyltrimethoxysilane modification on the surface of the modified nano-framework initially bonded to the perfluorooctyl groups on the surface of the modified nano-titanium dioxide through hydrophobic interactions. Then, the temperature was increased, and thermal motion promoted the more complete adsorption of the modified nano-titanium dioxide onto the porous surface and pores of the modified nano-framework. At the same time, the silanol groups remaining on the surface of the modified nano-titanium dioxide underwent a weak dehydration condensation reaction with the incompletely reacted hydroxyl groups on the surface of the modified nano-framework, forming a small amount of Si-O-Co covalent bonds to enhance the bonding stability. Finally, a coated composite material with the modified nano-framework as the substrate and modified nano-titanium dioxide loaded on the surface and in the pores was obtained.

[0023] Furthermore, the modified nano-titanium dioxide is prepared as follows: nano-titanium dioxide is added to an ethanol aqueous solution and stirred for 10-20 min. Then, the temperature is raised to 50-60℃, perfluorooctyltriethoxysilane is added, and stirring is continued for 4-5 h. After the reaction is completed, the mixture is filtered, and the filter cake is washed 3-4 times with anhydrous ethanol and then transferred to a vacuum drying oven and dried at 60-80℃ for 24 h to obtain modified nano-titanium dioxide. The ratio of nano-titanium dioxide, ethanol aqueous solution, and perfluorooctyltriethoxysilane is 3-4 g: 150 mL: 0.5 g, and the mass fraction of the ethanol aqueous solution is 90%.

[0024] Reaction mechanism:

[0025] The surface of nano-titanium dioxide naturally contains a large number of hydroxyl groups. In an aqueous ethanol solution, the ethoxy group of perfluorooctyltriethoxysilane molecule undergoes hydrolysis to generate silanol groups. Subsequently, the -Ti-OH on the surface of nano-titanium dioxide undergoes a dehydration condensation reaction with the -Si-OH generated by the hydrolysis of perfluorooctyltriethoxysilane to form a stable Si-O-Ti covalent bond. This allows silane molecules containing perfluorooctyl chains to be grafted onto the surface of nano-titanium dioxide, resulting in modified nano-titanium dioxide with perfluorooctyl hydrophobic segments grafted onto its surface.

[0026] Furthermore, the modified nanoframework is prepared by the following steps:

[0027] B1. Cobalt nitrate hexahydrate was added to a methanol solution and stirred until the solution was clear. Then 2-methylimidazole was added and stirred at 20-30℃ for 20-30 min. After standing for 24 h, the mixture was centrifuged and the product was washed 2-3 times with deionized water and methanol, respectively. The product was then transferred to a vacuum drying oven and dried at 60℃ for 24 h to obtain the nanoparticle framework.

[0028] B2. Add the nanoparticle framework to an ethanol aqueous solution and ultrasonically disperse for 10-20 min. Then add dodecyltrimethoxysilane and reflux at 80-90℃ for 24 h. After the reaction is complete, centrifuge and wash the product with anhydrous ethanol 3-4 times. Then transfer it to a vacuum drying oven and dry at 80℃ for 24 h to obtain the modified nanoframework.

[0029] Reaction mechanism:

[0030] Cobalt nitrate hexahydrate dissociates into Co in methanol solution. 2+ The nitrogen atom on the added 2-methylimidazolium has a lone pair of electrons, which interacts with Co. 2+ Coordination occurs, gradually forming tetrahedral coordination units, which are then assembled to construct a porous nanoparticle framework. Subsequently, ultrasonic dispersion is used to uniformly suspend the framework in anhydrous ethanol, exposing the Co atoms on the surface of the nanoparticle framework. 2+ The residual hydroxyl groups undergo a dehydration condensation reaction with the silanols generated by the hydrolysis of dodecyltrimethoxysilane to form stable Si-O-Co covalent bonds. This allows silane molecules containing long-chain alkyl groups to be grafted onto the surface of the nanoframework, ultimately yielding a modified nanoframework with surface-modified long-chain alkyl groups.

[0031] Furthermore, in step B1, the ratio of cobalt nitrate hexahydrate, methanol solution, and 2-methylimidazole is 1g:50-55mL:2-2.2g; in step B2, the ratio of the nanoparticle framework, anhydrous ethanol, and dodecyltrimethoxysilane is 1g:60mL:2mL.

[0032] Furthermore, the flame retardant is prepared by adding phytic acid and cytosine to a reaction vessel containing anhydrous ethanol, heating to 60-70℃, stirring for 1-2 hours, cooling to room temperature after the reaction, filtering, washing the filter cake 2-3 times with ethanol solution, transferring it to a vacuum drying oven, drying at 60℃ to constant weight, grinding, and passing it through a 200-mesh sieve to obtain the flame retardant; the ratio of phytic acid, cytosine, and anhydrous ethanol is 1g:1.1-1.3g:20-25mL.

[0033] Reaction mechanism:

[0034]

[0035] Phytic acid molecules contain multiple acidic phosphate groups, while the amino groups on the cytosine-pyrimidine ring are basic. In anhydrous ethanol, phytic acid dissociates into H+. + It combines with the amino group of cytosine to form -NH3 + Phytic acid itself forms phosphate anions, and the two are bonded by ionic bonds. Since the solubility of this complex in anhydrous ethanol is low, a solid precipitates when the reaction is cooled to room temperature. After washing and drying, a phosphorus-nitrogen synergistic intumescent flame retardant is obtained.

[0036] The present invention also proposes an anti-ultraviolet recycled polyester fiber fabric, which is prepared by the above-mentioned preparation process of an anti-ultraviolet recycled polyester fiber fabric.

[0037] The present invention has the following beneficial effects:

[0038] 1. The flame retardant of this invention, as a phosphorus-nitrogen synergistic expansion system, forms a stable structure through ionic bonding. The phosphorus and nitrogen elements it contains can promote the formation of an expanded char layer during combustion, achieving heat insulation and oxygen barrier. The modified nano zinc oxide relies on the porous loading structure of red mud and is uniformly dispersed in the fabric. The zinc element it contains can catalyze the solidification of the char layer and enhance its density. The porous nano-skeleton structure of titanium dioxide coated with nano-skeleton can adsorb the heat and smoke generated during combustion. At the same time, its dispersion characteristics avoid flame retardant failure caused by agglomeration. The ester bond structure in the recycled polyester molecular chain can slow down the high-temperature degradation rate and inhibit the release of combustible gases under the action of the flame retardant system. The above components, through the synergistic effect between elements and structural complementarity, construct a multiple flame retardant mechanism of char layer barrier-heat adsorption-degradation inhibition, effectively improving the flame retardant performance of the fabric.

[0039] 2. The polyethylene glycol and N,N'-Bis(2-hydroxyethyl)piperazine blocks introduced into the recycled polyester molecular chain of this invention provide basic flexibility to the fabric due to their flexible structure and multi-element composition. After modification by red mud porous structure loading and silane coupling agent, the modified nano zinc oxide not only forms a stable chemical bond with the recycled polyester matrix, but also disperses evenly inside the fiber, avoiding local stress concentration and enhancing the interfacial compatibility between the matrix and the filler. The nano-skeleton-coated titanium dioxide, with a porous nano-skeleton as the base, can form physical cross-linking points inside the fiber through its three-dimensional porous structure, improving the integrity and support strength of the fiber structure. Under the synergistic effect of the three, the fabric has good flexibility to adapt to tensile deformation, and can resist mechanical damage during the wear process through structural reinforcement, thereby simultaneously improving the elongation at break and abrasion resistance.

[0040] 3. The modified nano zinc oxide of this invention, as an ultraviolet absorber, contains zinc elements that can efficiently absorb UVA / UVB band ultraviolet rays. Furthermore, it achieves uniform dispersion by relying on the porous structure of red mud, expanding the ultraviolet contact area. The titanium elements contained in the nano-skeleton-coated titanium dioxide possess excellent ultraviolet reflection and scattering capabilities. Its nano-skeleton coating structure ensures its own dispersion stability and forms a complementary ultraviolet shielding system with the modified nano zinc oxide. Under the synergistic protection of the two ultraviolet-resistant fillers, the chemical structure of the recycled polyester molecular chain is protected from ultraviolet damage, avoiding performance degradation caused by molecular chain breakage. Simultaneously, the block structure of the recycled polyester and the chemical bonds of the ultraviolet-resistant fillers further enhance the system stability, enabling the fabric to maintain its original structure and performance under long-term ultraviolet radiation, significantly improving its anti-ultraviolet aging performance. Detailed Implementation

[0041] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] In this application, the polyethylene glycol is selected from Jinan Xinke Chemical Co., Ltd., CAS No. 25322-68-3, and the model is PEG400;

[0043] In this application, the red mud was selected from Shifeng Mining Processing Plant in Lingshou County, with a particle size of 325 and a purity of 99%.

[0044] In this application, the nano titanium dioxide is selected from Guangdong Yongfeng Chemical Co., Ltd., CAS No. 13463-67-7, and product number R-996.

[0045] Example 1

[0046] This embodiment provides a method for preparing a UV-resistant recycled polyester fiber fabric, including the following steps:

[0047] S1. Preparation of alcoholysis extract

[0048] The recycled polyester material is cleaned, disinfected, crushed, and passed through a 60-mesh sieve to obtain recycled polyester powder.

[0049] Weigh out 9g sodium hydroxide, 2g sodium dodecylbenzenesulfonate, 4g polyethylene glycol, 100mL anhydrous ethanol and 880mL deionized water and mix them evenly to obtain a pretreatment solution.

[0050] Weigh 1g of recycled polyester powder and 8mL of pretreatment solution and add them to the reaction vessel. Heat the mixture to 50℃ and stir for 50min. After the temperature of the reaction vessel drops to room temperature, filter the mixture. Wash the filter cake with ethanol solution until neutral and then dry it. Transfer the filter cake to a vacuum drying oven and dry it at 70℃ to constant weight to obtain pretreated polyester powder.

[0051] Weigh out 80g of pretreated polyester powder, 60mL of ethylene glycol and 0.8g of tetrabutyl titanate and add them to the reaction vessel. Heat the mixture to 160℃ and keep it at that temperature for 5 hours. After the temperature of the reaction vessel drops to room temperature, add 1600mL of 2wt% sodium dodecylbenzenesulfonate aqueous solution to the reaction system, stir for 20 minutes, filter, wash the filter cake three times with deionized water and dry it under vacuum. Transfer the filter cake to a vacuum drying oven and dry it at 70℃ to constant weight to obtain the alcoholysis extract.

[0052] S2, Preparation of recycled polyester

[0053] Weigh out 100g of alcoholysis extract, 12g of 1,4-butanediol and 0.12g of antimony trioxide catalyst and add them to a reaction vessel. Heat the mixture to 215℃ under a nitrogen atmosphere and stir for 1 hour. Then add 8g of polyethylene glycol and 3g of N,N'-Bis(2-hydroxyethyl)piperazine and stir for 20 minutes. Evacuate the reaction system to a vacuum pressure of -0.1MPa and maintain the temperature for 1 hour. When the stirring output power increases by 10% at a constant speed, discharge the material to obtain recycled polyester.

[0054] S3, Preparation of modified nano zinc oxide

[0055] Weigh out 5g of red mud and 0.01g of cetyltrimethylammonium bromide and add them to 40mL of deionized water. Stir at 70℃ for 1h, filter, wash the filter cake three times with deionized water, transfer it to a vacuum drying oven, and vacuum dry at 60℃ for 4h to obtain pretreated red mud.

[0056] KH-560 and deionized water were mixed at a volume ratio of 1:10 and stirred for 20 minutes to obtain a silane coupling agent solution.

[0057] Weigh out 10g of pretreated red mud and 3g of nano zinc oxide and mix them in 45mL of anhydrous ethanol. Stir at 20℃ for 20min. Then add 8mL of silane coupling agent solution dropwise. After the addition is complete, continue stirring for 1h. After the reaction is complete, filter the mixture. Wash the filter cake three times with anhydrous ethanol and transfer it to a vacuum drying oven. Dry it at 100℃ to constant weight, grind it, and pass it through a 200-mesh sieve to obtain modified nano zinc oxide.

[0058] S4. Preparation of modified nano-titanium dioxide

[0059] Weigh 3g of nano-titanium dioxide and add it to 150mL of 90wt% ethanol aqueous solution. Stir for 10min, then heat to 50℃ and add 0.5g of perfluorooctyltriethoxysilane. Continue stirring for 4h. After the reaction is complete, filter the mixture and wash the filter cake three times with anhydrous ethanol. Then transfer it to a vacuum drying oven and dry it at 60℃ for 24h to obtain modified nano-titanium dioxide.

[0060] S5. Preparation of modified nanoframeworks

[0061] Weigh 1g of cobalt nitrate hexahydrate and add it to 50mL of methanol solution. Stir until the solution is clear, then add 2g of 2-methylimidazole. Stir at 20℃ for 20min, let stand for 24h, centrifuge, wash the product twice with deionized water and methanol respectively, transfer it to a vacuum drying oven, and dry at 60℃ for 24h to obtain the nanoparticle framework.

[0062] Weigh 1g of nanoparticle framework and add it to 60mL of 85wt% ethanol aqueous solution. Disperse it by sonication for 10min. Then add 2mL of dodecyltrimethoxysilane and reflux at 80℃ for 24h. After the reaction is completed, centrifuge the product and wash it three times with anhydrous ethanol. Then transfer it to a vacuum drying oven and dry it at 80℃ for 24h to obtain the modified nanoframework.

[0063] S6. Preparation of nanoframework coated with titanium dioxide

[0064] Weigh 0.1g of modified nano-titanium dioxide and add it to 50mL of dimethylformyl. Disperse it by sonication for 30min. Then add 0.1g of modified nano-framework and continue to disperse by sonication for 40min. Then heat to 70℃ and stir for 24h. After the reaction is complete, filter and wash the filter cake three times with anhydrous ethanol. Then transfer it to a vacuum drying oven and dry it at 60℃ for 24h. Grind it and pass it through a 200-mesh sieve to obtain nano-framework coated titanium dioxide.

[0065] S7. Preparation of flame retardants

[0066] Weigh 10g of phytic acid and 11g of cytosine and add them to a reaction vessel containing 200mL of anhydrous ethanol. Heat the mixture to 60℃ and stir for 1h. After the reaction is complete, cool to room temperature, filter, wash the filter cake twice with ethanol solution, transfer it to a vacuum drying oven, dry it at 60℃ to constant weight, grind it, and pass it through a 200-mesh sieve to obtain the flame retardant.

[0067] S8. Preparation of recycled polyester fibers

[0068] Weigh out 100g of recycled polyester, 1.5g of modified nano zinc oxide, 1g of nano-structured titanium dioxide, 10g of flame retardant, and 1g of auxiliary additives, mix them, and add them to a twin-screw extruder. The twin-screw extruder has six temperature zones set from the feed end towards the die head, with temperatures of 250℃, 255℃, 260℃, 265℃, 260℃, and 255℃ respectively. The spindle speed of the twin-screw extruder is 20r / min. The fibers are melt-extruded into a spinning machine and spun at 260℃. After being stretched twice at a speed of 600m / min, the fibers are completely immersed in a 5wt% sodium dodecyl sulfate solution, ultrasonically dispersed for 20min, removed, washed three times with deionized water, and dried to obtain recycled polyester fibers.

[0069] S9. Preparation of recycled polyester fiber fabric

[0070] Recycled polyester fibers are added to a weaving machine and woven using a warp and weft weaving method with a warp density of 130 count and a weft density of 90 count to obtain recycled polyester fiber fabric.

[0071] Example 2

[0072] This embodiment provides a method for preparing a UV-resistant recycled polyester fiber fabric, including the following steps:

[0073] S1. Preparation of alcoholysis extract

[0074] The recycled polyester material is cleaned, disinfected, crushed, and passed through a 60-mesh sieve to obtain recycled polyester powder.

[0075] Weigh out 10g sodium hydroxide, 2.5g sodium dodecylbenzenesulfonate, 5g polyethylene glycol, 100mL anhydrous ethanol and 880mL deionized water and mix them well to obtain a pretreatment solution.

[0076] Weigh 1g of recycled polyester powder and 10mL of pretreatment solution and add them to the reaction vessel. Heat the mixture to 55℃ and stir for 55min. After the temperature of the reaction vessel drops to room temperature, filter the mixture. Wash the filter cake with ethanol solution until it is neutral and then dry it. Transfer the filter cake to a vacuum drying oven and dry it at 70℃ to a constant weight to obtain pretreated polyester powder.

[0077] Weigh out 90g of pretreated polyester powder, 60mL of ethylene glycol and 0.8g of tetrabutyl titanate and add them to the reaction vessel. Heat the mixture to 170℃ and keep it at that temperature for 5.5h. After the temperature of the reaction vessel has dropped to room temperature, add 1800mL of 2wt% sodium dodecylbenzenesulfonate aqueous solution to the reaction system, stir for 25min, filter, wash the filter cake four times with deionized water and dry it under vacuum. Transfer the filter cake to a vacuum drying oven and dry it at 75℃ to constant weight to obtain the alcoholysis extract.

[0078] S2, Preparation of recycled polyester

[0079] Weigh out 100g of alcoholysis extract, 13g of 1,4-butanediol and 0.13g of antimony trioxide catalyst and add them to a reaction vessel. Heat the mixture to 220℃ under a nitrogen atmosphere and stir for 1.5h. Then add 9g of polyethylene glycol and 4g of N,N'-Bis(2-hydroxyethyl)piperazine and stir for 25min. Evacuate the reaction system to a vacuum pressure of -0.1MPa and maintain the temperature for 1.5h. When the stirring output power increases by 15% at a constant speed, discharge the material to obtain recycled polyester.

[0080] S3, Preparation of modified nano zinc oxide

[0081] Weigh out 5.5g of red mud and 0.01g of cetyltrimethylammonium bromide and add them to 40mL of deionized water. Stir at 75℃ for 1.5h, filter, wash the filter cake 4 times with deionized water, transfer it to a vacuum drying oven, and vacuum dry at 60℃ for 4h to obtain pretreated red mud.

[0082] KH-560 and deionized water were mixed at a volume ratio of 1:10 and stirred for 25 minutes to obtain a silane coupling agent solution.

[0083] Weigh out 10g of pretreated red mud and 3g of nano zinc oxide, mix them and add them to 45mL of anhydrous ethanol. Stir at 25℃ for 25min, then add 9mL of silane coupling agent solution dropwise. After the addition is complete, continue stirring for 1.5h. After the reaction is complete, filter, wash the filter cake 4 times with anhydrous ethanol, transfer it to a vacuum drying oven, dry it at 100℃ to constant weight, grind it and pass it through a 200-mesh sieve to obtain modified nano zinc oxide.

[0084] S4. Preparation of modified nano-titanium dioxide

[0085] Weigh 3.5g of nano-titanium dioxide and add it to 150mL of 90wt% ethanol aqueous solution. Stir for 15min, then heat to 55℃ and add 0.5g of perfluorooctyltriethoxysilane. Continue stirring for 4.5h. After the reaction is complete, filter the mixture and wash the filter cake three times with anhydrous ethanol. Then transfer it to a vacuum drying oven and dry it at 70℃ for 24h to obtain modified nano-titanium dioxide.

[0086] S5. Preparation of modified nanoframeworks

[0087] Weigh 1g of cobalt nitrate hexahydrate and add it to 50mL of methanol solution. Stir until the solution is clear, then add 2.1g of 2-methylimidazole. Stir at 25℃ for 25min, let stand for 24h, centrifuge, wash the product twice with deionized water and methanol respectively, transfer it to a vacuum drying oven, and dry at 60℃ for 24h to obtain the nanoparticle framework.

[0088] Weigh 1g of nanoparticle framework and add it to 60mL of 85wt% ethanol aqueous solution. Disperse it by sonication for 15min. Then add 2mL of dodecyltrimethoxysilane and reflux at 85℃ for 24h. After the reaction is completed, centrifuge the product and wash it three times with anhydrous ethanol. Then transfer it to a vacuum drying oven and dry it at 80℃ for 24h to obtain the modified nanoframework.

[0089] S6. Preparation of nanoframework coated with titanium dioxide

[0090] Weigh 0.1g of modified nano-titanium dioxide and add it to 50mL of dimethylformyl. Disperse it by sonication for 35min. Then add 0.1g of modified nano-framework and continue to disperse by sonication for 45min. Then heat to 75℃ and stir for 24h. After the reaction is complete, filter and wash the filter cake 4 times with anhydrous ethanol. Then transfer it to a vacuum drying oven and dry it at 60℃ for 24h. Grind it and pass it through a 200-mesh sieve to obtain nano-framework coated titanium dioxide.

[0091] S7. Preparation of flame retardants

[0092] Weigh 10g of phytic acid and 12g of cytosine and add them to a reaction vessel containing 220mL of anhydrous ethanol. Heat the mixture to 65℃ and stir for 1.5h. After the reaction is complete, cool to room temperature, filter, wash the filter cake twice with ethanol solution, transfer it to a vacuum drying oven, dry it at 60℃ to constant weight, grind it, and pass it through a 200-mesh sieve to obtain the flame retardant.

[0093] S8. Preparation of recycled polyester fibers

[0094] Weigh out 100g of recycled polyester, 2g of modified nano zinc oxide, 1.5g of nano-structured titanium dioxide, 12g of flame retardant, and 1.5g of auxiliary additives, mix them, and add them to a twin-screw extruder. The twin-screw extruder has six temperature zones set from the feed end towards the die head, with temperatures of 250℃, 255℃, 260℃, 265℃, 260℃, and 255℃ respectively. The spindle speed of the twin-screw extruder is 20r / min. The fibers are melt-extruded into a spinning machine and spun at 270℃. After being stretched twice at a speed of 700m / min, the fibers are completely immersed in a 5wt% sodium dodecyl sulfate solution, ultrasonically dispersed for 25min, removed, washed three times with deionized water, and dried to obtain recycled polyester fibers.

[0095] S9. Preparation of recycled polyester fiber fabric

[0096] Recycled polyester fibers are added to a braiding machine and woven using a warp and weft weaving method with a warp density of 140 count and a weft density of 95 count to obtain recycled polyester fiber fabric.

[0097] Example 3

[0098] This embodiment provides a method for preparing a UV-resistant recycled polyester fiber fabric, including the following steps:

[0099] S1. Preparation of alcoholysis extract

[0100] The recycled polyester material is cleaned, disinfected, crushed, and passed through a 60-mesh sieve to obtain recycled polyester powder.

[0101] Weigh out 11g sodium hydroxide, 3g sodium dodecylbenzenesulfonate, 6g polyethylene glycol, 100mL anhydrous ethanol and 880mL deionized water and mix them evenly to obtain a pretreatment solution.

[0102] Weigh 1g of recycled polyester powder and 12mL of pretreatment solution and add them to the reactor. Heat the reactor to 60℃ and stir for 60min. After the reactor temperature drops to room temperature, filter the mixture. Wash the filter cake with ethanol solution until neutral and then dry it. Transfer the filter cake to a vacuum drying oven and dry it at 70℃ to constant weight to obtain pretreated polyester powder.

[0103] Weigh 100g of pretreated polyester powder, 60mL of ethylene glycol and 0.8g of tetrabutyl titanate and add them to the reaction vessel. Heat the mixture to 180℃ and keep it at that temperature for 6 hours. After the temperature of the reaction vessel has dropped to room temperature, add 2000mL of 2wt% sodium dodecylbenzenesulfonate aqueous solution to the reaction system, stir for 30 minutes, filter, wash the filter cake 5 times with deionized water and dry it under vacuum. Transfer the filter cake to a vacuum drying oven and dry it at 80℃ to constant weight to obtain the alcoholysis extract.

[0104] S2, Preparation of recycled polyester

[0105] Weigh out 100g of alcoholysis extract, 14g of 1,4-butanediol and 0.15g of antimony trioxide catalyst and add them to a reaction vessel. Heat the mixture to 225℃ under a nitrogen atmosphere and stir for 2 hours. Then add 10g of polyethylene glycol and 5g of N,N'-Bis(2-hydroxyethyl)piperazine and stir for 30 minutes. Evacuate the reaction system to a vacuum pressure of -0.1MPa and maintain the temperature for 2 hours. When the stirring output power increases by 20% at a constant speed, discharge the material to obtain recycled polyester.

[0106] S3, Preparation of modified nano zinc oxide

[0107] Weigh out 6g of red mud and 0.02g of cetyltrimethylammonium bromide and add them to 40mL of deionized water. Stir at 80℃ for 2h, filter, wash the filter cake 5 times with deionized water, transfer it to a vacuum drying oven, and vacuum dry at 60℃ for 4h to obtain pretreated red mud.

[0108] KH-560 and deionized water were mixed at a volume ratio of 1:10 and stirred for 30 minutes to obtain a silane coupling agent solution.

[0109] Weigh out 10g of pretreated red mud and 3g of nano zinc oxide and mix them in 50mL of anhydrous ethanol. Stir at 30℃ for 30min. Then add 10mL of silane coupling agent solution dropwise. After the addition is complete, continue stirring for 2h. After the reaction is complete, filter the mixture. Wash the filter cake 5 times with anhydrous ethanol and transfer it to a vacuum drying oven. Dry it at 100℃ to constant weight, grind it, and pass it through a 200-mesh sieve to obtain modified nano zinc oxide.

[0110] S4. Preparation of modified nano-titanium dioxide

[0111] Weigh 4g of nano-titanium dioxide and add it to 150mL of 90wt% ethanol aqueous solution. Stir for 20min, then heat to 60℃ and add 0.5g of perfluorooctyltriethoxysilane. Continue stirring for 5h. After the reaction is complete, filter and wash the filter cake 4 times with anhydrous ethanol. Then transfer it to a vacuum drying oven and dry at 80℃ for 24h to obtain modified nano-titanium dioxide.

[0112] S5. Preparation of modified nanoframeworks

[0113] Weigh 1g of cobalt nitrate hexahydrate and add it to 55mL of methanol solution. Stir until the solution is clear, then add 2.2g of 2-methylimidazole. Stir at 30℃ for 30min, let stand for 24h, centrifuge, wash the product three times with deionized water and methanol respectively, transfer it to a vacuum drying oven, and dry at 60℃ for 24h to obtain the nanoparticle framework.

[0114] Weigh 1g of nanoparticle framework and add it to 60mL of 85wt% ethanol aqueous solution. Disperse it by sonication for 20min. Then add 2mL of dodecyltrimethoxysilane and reflux at 90℃ for 24h. After the reaction is complete, centrifuge the product and wash it 4 times with anhydrous ethanol. Then transfer it to a vacuum drying oven and dry it at 80℃ for 24h to obtain the modified nanoframework.

[0115] S6. Preparation of nanoframework coated with titanium dioxide

[0116] Weigh 0.1g of modified nano-titanium dioxide and add it to 55mL of dimethylformyl. Disperse it by sonication for 40min. Then add 0.1g of modified nano-framework and continue to disperse by sonication for 50min. Then heat to 80℃ and stir for 24h. After the reaction is complete, filter and wash the filter cake 5 times with anhydrous ethanol. Then transfer it to a vacuum drying oven and dry it at 60℃ for 24h. Grind it and pass it through a 200-mesh sieve to obtain nano-framework coated titanium dioxide.

[0117] S7. Preparation of flame retardants

[0118] Weigh 10g of phytic acid and 13g of cytosine and add them to a reaction vessel containing 250mL of anhydrous ethanol. Heat the mixture to 70℃ and stir for 2 hours. After the reaction is complete, cool to room temperature, filter, wash the filter cake three times with ethanol solution, transfer it to a vacuum drying oven, dry it at 60℃ to constant weight, grind it, and pass it through a 200-mesh sieve to obtain the flame retardant.

[0119] S8. Preparation of recycled polyester fibers

[0120] Weigh out 100g of recycled polyester, 2.5g of modified nano zinc oxide, 2g of nano-structured titanium dioxide, 14g of flame retardant, and 2g of auxiliary additives, mix them, and add them to a twin-screw extruder. The twin-screw extruder has six temperature zones set from the feed end towards the die head, with temperatures of 250℃, 255℃, 260℃, 265℃, 260℃, and 255℃ respectively. The spindle speed of the twin-screw extruder is 20r / min. The fibers are melt-extruded into a spinning machine and spun at 280℃. After being stretched three times at a speed of 800m / min, the fibers are completely immersed in a 5wt% sodium dodecyl sulfate solution, ultrasonically dispersed for 30min, removed, washed four times with deionized water, and dried to obtain recycled polyester fibers.

[0121] S9. Preparation of recycled polyester fiber fabric

[0122] Recycled polyester fibers are added to a weaving machine and woven using a warp and weft weaving method with a warp density of 150 count and a weft density of 100 count to obtain recycled polyester fiber fabric.

[0123] Comparative Example 1

[0124] The difference between this comparative example and Example 3 is that step S3 is omitted, and the modified nano zinc oxide in step S8 is replaced with nano zinc oxide in step S3.

[0125] Comparative Example 2

[0126] The difference between this comparative example and Example 3 is that step S4 is omitted, and the modified nano-titanium dioxide in step S6 is replaced with the nano-titanium dioxide in step S4.

[0127] Comparative Example 3

[0128] The difference between this comparative example and Example 3 is that step S6 is omitted, and the modified nanoframework prepared in step S5 is used to replace the nanoframework coating titanium dioxide in step S8.

[0129] Comparative Example 4

[0130] The difference between this comparative example and Example 3 is that step S7 is omitted, and the flame retardant in step S8 is replaced with phytic acid from step S7.

[0131] Performance testing:

[0132] The vertical flammability ratings of the recycled polyester fiber fabrics prepared in Examples 1-3 and Comparative Examples 1-4 were tested according to the standard GB / T 2408-2021 "Determination of the flammability of plastics - Horizontal and Vertical Methods".

[0133] The abrasion resistance index of the recycled polyester fiber fabrics prepared in Examples 1-3 and Comparative Examples 1-4 was tested in accordance with the standard GB / T 21196.3-2007 "Textiles - Martindale Method - Determination of Abrasion Resistance of Fabrics - Part 3: Determination of Mass Loss".

[0134] The elongation at break of the recycled polyester fiber fabrics prepared in Examples 1-3 and Comparative Examples 1-4 was determined in accordance with the standard GB / T 3923.1-2013 "Textiles - Tensile Properties of Fabrics - Part 1: Determination of Breaking Strength and Elongation at Break (Strip Method)".

[0135] Referring to standard GB / T 16991-2008 "Textiles - Tests for color fastness to artificial light - Color fastness and anti-aging properties - Xenon arc", clean xenon arc lamps were used. The recycled polyester fiber fabric samples prepared in Examples 1-3 and Comparative Examples 1-4 were fixed with sample clips and continuously exposed to sunlight for one week. Their UV aging properties were then measured. The specific test results are shown in Table 1 below:

[0136] Table 1 - Performance Test Data of Samples

[0137]

[0138] Data Analysis:

[0139] Comparative analysis of the data in Table 1 above shows that the recycled polyester fiber fabric prepared by this invention has a vertical burning rating of V-0, an abrasion resistance index of 7933 cycles / mg, and a breaking elongation of 37.2% before heat aging; after heat aging, the vertical burning rating is V-0, the abrasion resistance index is 7377 cycles / mg, and the breaking elongation is 33.8%.

[0140] Comparative Example 1: Replacing modified nano-zinc oxide with unmodified nano-zinc oxide resulted in the nano-zinc oxide lacking the loading effect of the porous structure of red mud and the chemical bonding modification of silane coupling agent. It was unevenly dispersed in the recycled polyester matrix and had poor compatibility with the matrix. It could neither enhance the flame retardant effect by solidifying the carbon layer through zinc element catalysis, nor avoid local stress concentration to improve mechanical properties. At the same time, the failure of uniform dispersion led to a reduction in the UV-resistant contact area. Ultimately, the vertical burning rating of the fabric before aging dropped to V-1, the elongation at break dropped to 30.3%, and the abrasion resistance index dropped to 6671 times / mg. After aging, the vertical burning rating further dropped to V-2, and the elongation at break and abrasion resistance index also showed a significant decline. The UV aging resistance and overall performance deteriorated simultaneously.

[0141] In Comparative Example 2, unmodified nano-titanium dioxide was used instead of modified nano-titanium dioxide. As a result, the surface of the nano-titanium dioxide was not grafted with perfluorooctyl hydrophobic chains, and it could not achieve stable binding with the modified nano-framework through hydrophobic interactions. This not only destroyed the synergistic anti-UV system of the nano-framework-coated titanium dioxide, but also affected the heat adsorption during the flame retardant process due to insufficient dispersion stability. Ultimately, the vertical burning rating of the fabric before aging was V-1, the elongation at break was 33.2%, and the abrasion resistance index was 6996 times / mg. After aging, the elongation at break dropped to 28.9%, and the abrasion resistance index was 6351 times / mg. The protective effect of anti-UV aging on mechanical properties failed, and the overall performance declined.

[0142] In Comparative Example 3, the modified nano-skeleton directly replaced the nano-skeleton to coat titanium dioxide, causing the system to lose the ultraviolet shielding function of the modified nano-titanium dioxide and the heat adsorption effect of the porous structure. It could neither form a complementary anti-ultraviolet system with the modified nano-zinc oxide, nor improve the flame retardant performance by adsorbing heat and strengthening the char layer barrier effect during combustion. At the same time, it lacked the support of physical cross-linking points for the fiber structure. Ultimately, the fabric's elongation at break before aging was 31.8% and the abrasion resistance index was 6939 times / mg. After aging, the elongation at break was only 27.1% and the abrasion resistance index was 5908 times / mg. The degradation of anti-ultraviolet aging performance and mechanical properties was the most obvious, and the flame retardant level was maintained in the V-1 to V-2 range.

[0143] In Comparative Example 4, phytic acid was used to directly replace the phytic acid-cytosine composite flame retardant, which caused the system to lose the synergistic expansion flame retardant effect of phosphorus and nitrogen. Phytic acid alone could not form a dense and stable expansion char layer. It could not effectively insulate heat and oxygen to improve flame retardant performance. Moreover, the loose char layer could not protect the fiber matrix, which aggravated the decline in mechanical properties. Ultimately, the vertical burning rating of the fabric before aging was only V-2, the elongation at break was 35.1%, and the abrasion resistance index was 7250 times / mg. After aging, the elongation at break dropped to 29.8% and the abrasion resistance index was 6543 times / mg. The insufficient flame retardant performance directly caused the overall decline in comprehensive performance.

[0144] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a UV-resistant recycled polyester fiber fabric, characterized in that, Includes the following steps: S1. The recycled polyester material is cleaned, disinfected, and then crushed. The crushed polyester material is then subjected to alcoholysis to obtain an alcoholysis extract. S2. Add the alcoholysis extract, 1,4-butanediol and catalyst to the reactor, heat to 215-225℃ under nitrogen atmosphere, stir for 1-2 hours, then add polyethylene glycol and N,N'-Bis(2-hydroxyethyl)piperazine, stir for 20-30 minutes, evacuate the reaction system to a vacuum pressure of -0.1MPa, keep the reaction at this temperature for 1-2 hours, and wait until the stirring output power increases by 10-20% at a constant speed, then discharge the material to obtain recycled polyester. S3. After mixing recycled polyester, modified nano zinc oxide, nano-framework coated titanium dioxide, flame retardant and auxiliary additives, add it to a twin-screw extruder and hot-melt extrude it into a spinning machine. After melt spinning, stretching and impregnation, recycled polyester fiber is obtained. S4. Add recycled polyester fibers to a weaving machine and weave them using a warp and weft weaving method to obtain recycled polyester fiber fabric.

2. The method for preparing an anti-ultraviolet recycled polyester fiber fabric according to claim 1, characterized in that, In step S2, the mass ratio of the alcoholysis extract, 1,4-butanediol, catalyst, polyethylene glycol, and N,N'-Bis(2-hydroxyethyl)piperazine is 100:12-14:0.12-0.15:8-10:3-5, and the catalyst is antimony trioxide. In step S3, the mass ratio of the recycled polyester, modified nano zinc oxide, nano-framework coated titanium dioxide, flame retardant, and auxiliary additives is 100:1.5-2.5:1-2:10-14:1-2, and the temperatures of the six temperature zones of the twin-screw extruder, set from the feed end toward the die head, are sequentially set to 250℃, 255℃, 260℃, 265℃, 260℃, and 255℃.

3. The method for preparing an anti-ultraviolet recycled polyester fiber fabric according to claim 1, characterized in that, In step S3, the modified nano-zinc oxide is prepared by the following steps: A1. Add red mud and hexadecyltrimethylammonium bromide to deionized water, stir at 70-80℃ for 1-2 hours, and then perform post-treatment to obtain pretreated red mud; A2. Mix the pretreated red mud and nano zinc oxide and add them to anhydrous ethanol. Stir at 20-30℃ for 20-30 min. Then add silane coupling agent solution dropwise. After the addition is complete, continue stirring for 1-2 h. After post-treatment, modified nano zinc oxide is obtained.

4. The method for preparing an anti-ultraviolet recycled polyester fiber fabric according to claim 3, characterized in that, In step A1, the ratio of red mud, hexadecyltrimethylammonium bromide, and deionized water is 5-6g:0.01-0.02g:40mL; in step A2, the ratio of pretreated red mud, nano zinc oxide, anhydrous ethanol, and silane coupling agent solution is 10g:3g:45-50mL:8-10mL; the silane coupling agent solution is obtained by mixing KH-560 and deionized water at a volume ratio of 1:10 and stirring for 20-30 minutes.

5. The method for preparing an anti-ultraviolet recycled polyester fiber fabric according to claim 1, characterized in that, In step S3, the preparation of the nano-framework-coated titanium dioxide is as follows: modified nano-titanium dioxide is added to dimethylformyl and ultrasonically dispersed for 30-40 min. Then, the modified nano-framework is added and ultrasonically dispersed for another 40-50 min. The mixture is then heated to 70-80℃ and stirred for 24 h. After post-treatment, nano-framework-coated titanium dioxide is obtained. The ratio of the amount of modified nano-titanium dioxide, dimethylformyl, and modified nano-framework is 0.1 g: 50-55 mL: 0.1 g.

6. The method for preparing an anti-ultraviolet recycled polyester fiber fabric according to claim 5, characterized in that, The modified nano-titanium dioxide is prepared as follows: nano-titanium dioxide is added to an ethanol aqueous solution and stirred for 10-20 min. Then, the temperature is raised to 50-60℃, perfluorooctyltriethoxysilane is added, and stirring is continued for 4-5 h. After post-treatment, modified nano-titanium dioxide is obtained. The ratio of nano-titanium dioxide, ethanol aqueous solution, and perfluorooctyltriethoxysilane is 3-4 g: 150 mL: 0.5 g, and the mass fraction of the ethanol aqueous solution is 90%.

7. The method for preparing an anti-ultraviolet recycled polyester fiber fabric according to claim 5, characterized in that, The modified nanoframework was prepared by the following steps: B1. Cobalt nitrate hexahydrate was added to a methanol solution and stirred until the solution was clear. Then 2-methylimidazole was added to the solution and stirred at 20-30℃ for 20-30 min. After standing for 24 h, the solution was centrifuged and then processed to obtain the nanoparticle framework. B2. Add the nanoparticle framework to an ethanol aqueous solution and ultrasonically disperse for 10-20 min. Then add dodecyltrimethoxysilane and reflux at 80-90℃ for 24 h. After post-treatment, the modified nanoframework is obtained.

8. The method for preparing an anti-ultraviolet recycled polyester fiber fabric according to claim 7, characterized in that, In step B1, the ratio of cobalt nitrate hexahydrate, methanol solution, and 2-methylimidazole is 1g:50-55mL:2-2.2g; in step B2, the ratio of the nanoparticle framework, anhydrous ethanol, and dodecyltrimethoxysilane is 1g:60mL:2mL.

9. The method for preparing an anti-ultraviolet recycled polyester fiber fabric according to claim 1, characterized in that, The flame retardant is prepared by adding phytic acid and cytosine to a reaction vessel containing anhydrous ethanol, heating to 60-70℃, stirring for 1-2 hours, and then performing post-treatment to obtain the flame retardant; the ratio of phytic acid, cytosine and anhydrous ethanol is 1g:1.1-1.3g:20-25mL.

10. A UV-resistant recycled polyester fiber fabric, characterized in that, The UV-resistant recycled polyester fiber fabric is prepared using the recycled polyester fiber fabric preparation process described in any one of claims 1-9.

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