Antibacterial and mildew-proof polyester long fiber and preparation method thereof

Abstract

The invention discloses an antibacterial and mildew-proof polyester long fiber and a preparation method thereof, belongs to the technical field of fiber preparation, and is used for solving the technical problem that the antibacterial property and mildew-proof property of the polyester fiber in the prior art need to be further improved. The method specifically comprises the following steps that the surface of polyester fiber is modified with a silver-loaded MOFs structure, the antibacterial polyester fiber is obtained, the antibacterial polyester fiber with the antibacterial performance and the structural stability is constructed through collaborative integration of three kinds of organic-inorganic-metal functional units, and the technical core thought is that an imidazole structure serves as a metal coordination core; a graphene-titanium oxide composite interface is used as a functional carrier, a chain extension reaction is introduced to realize that a functional group is embedded into a polyester main chain, and finally, the material is endowed with excellent antibacterial property and functional durability through in-situ construction of ZIF-8 and silver nanoparticles.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fiber preparation, in particular to an antibacterial and mildew-proof polyester long fiber and a preparation method thereof. BACKGROUND

[0002] The antibacterial and mildew-proof polyester fiber is a functional fiber with antibacterial and mildew-proof properties imparted by physical or chemical methods on the basis of conventional polyester, and is widely used in medical, home, clothing and public places with high hygiene requirements.

[0003] Although the conventional polyester has excellent mechanical properties and heat resistance, it has poor hydrophilicity, easily adsorbs stains and breeds microorganisms, affecting the safety and comfort of use. In order to overcome this problem, researchers introduce antibacterial agents during fiber spinning or use finishing processes to impart long-lasting antibacterial and mildew-proof ability to the fiber. Such fibers effectively inhibit the growth of bacteria, fungi and other microorganisms while ensuring the basic properties of the fabric, prolong the service life of the product and improve the level of hygiene and safety. With the improvement of people's quality of life and health awareness, antibacterial and mildew-proof polyester fibers are becoming an important development direction of functional textile materials, and have broad market prospects and application value.

[0004] As prior art CN110606944B discloses an anti-mildew polyester with high wash resistance and a preparation method thereof. The anti-mildew polyester is prepared by using terephthalic acid and ethylene glycol as starting materials, adding a modifier after the esterification reaction of terephthalic acid and ethylene glycol, and participating in the polymerization reaction to obtain modified anti-mildew polyester. The organic silicon and quaternary ammonium salt are introduced into the polyester in a chemical bonding manner. The N positive ion in the quaternary ammonium salt is combined with the fiber surface in a chemical bond form, thereby attracting negative fungi, bacteria and the like, restraining the activity of bacteria, and entering the cells by the cell membrane of the bacteria to destroy the metabolism of enzymes in the cells and cause cell death, achieving the effect of killing bacteria or inhibiting the growth of bacteria. Because the N positive ion is combined with the fiber surface in a chemical bond form, it is not easy to fall off, has strong wash resistance, and can long-term maintain the antibacterial and mildew-proof properties of the polyester fabric.

[0005] However, the above-mentioned application introduces organic silicon and quaternary ammonium salt by chemical bonding, which significantly improves the mildew-proof performance and wash resistance of the fiber. However, in terms of antibacterial and mildew-proof performance, the antibacterial agent is attached to the surface of the fiber in the form of non-covalent bonding, lacks stable chemical bond support, and is easily affected by environmental factors such as washing, friction and ultraviolet light, and gradually loses, resulting in rapid attenuation of antibacterial effect, poor persistence, and difficulty in achieving long-term stable inhibition of bacteria.

[0006] On the other hand, since the functional components are not embedded in the main chain structure of the polyester molecules, the adhesion is weak, and the functional layer falls off significantly after multiple washes, causing the antifungal performance of the fiber to rapidly decrease, making it difficult to meet the durability requirements in actual application under repeated washing and long-term wearing environment, and therefore a solution is proposed. SUMMARY

[0007] The purpose of the present application is to provide an antibacterial and antifungal polyester long fiber and a preparation method thereof, to solve the technical problem that the antibacterial and antifungal performance of the polyester fiber in the prior art needs to be further improved.

[0008] The purpose of the present application can be achieved by the following technical solution: a preparation method of an antibacterial and antifungal polyester long fiber, comprising the following steps:

[0009] S1, preparing a hydroxyl-terminated polyester by vacuum polycondensation with terephthalic acid and ethylene glycol as raw materials;

[0010] S2, adding the hydroxyl-terminated polyester and p-toluenesulfonic acid to a reaction kettle, protecting by nitrogen, increasing the temperature of the reaction kettle to 130-160 DEG C, adding a modified chain extender to the reaction kettle, keeping warm for 1-2 hours, adding a capping agent to the reaction kettle, keeping warm for 30-40 minutes, and post-treating to obtain a modified polyester;

[0011] The reaction equation for preparing the modified polyester is:

[0012]

[0013] In the formula: The modified chain extender is represented by.

[0014] The reaction principle for preparing the modified polyester is that the hydroxyl groups at the chain ends of the hydroxyl-terminated polyester and the carboxyl groups in the chain extender molecules undergo esterification reaction to form new ester bonds, extend the molecular chain length, and introduce the molecular structure of the modified chain extender into the polyester main chain, and then the amino groups of 2-amino-1H-imidazole-4-carboxylic acid continue to undergo condensation reaction with the ester groups remaining in the modified chain extender to introduce imidazole structural units and form covalent bonds, and the entire process realizes the gradual chemical combination of the polyester chain, the modified chain extender and the imidazole functional group, and finally the modified polyester is prepared.

[0015] S3, according to the weight parts, 80-100 parts of the modified polyester and 10-16 parts of the auxiliary are weighed into a twin-screw extruder, melted and extruded, then transferred to a side-blowing chamber through a spinneret, and then solidified by air cooling to obtain a polyester fiber;

[0016] S4, modifying the silver-loaded MOFs structure on the surface of the polyester fiber to obtain an antibacterial polyester fiber.

[0017] Further, in step S1, the preparation method of the hydroxyl-terminated polyester is as follows: terephthalic acid, antimony trioxide and a calculated amount of ethylene glycol are added into a reaction kettle, the temperature of the reaction kettle is increased to 220-240℃, and after heat preservation for 2-3h, the temperature of the reaction kettle is increased to 260-280℃ and the reaction kettle is subjected to vacuum treatment, the internal gas pressure of the reaction kettle is reduced to 100-120Pa within 30-45min, heat preservation is performed for 40-60min, and post-treatment is performed to obtain the hydroxyl-terminated polyester; wherein the amount ratio of terephthalic acid to antimony trioxide is 10-12g:0.03-0.04g, and the amount of ethylene glycol is 1.1-1.2 times the molar amount of carboxyl groups in the reaction system.

[0018] The reaction equation for preparing the hydroxyl-terminated polyester is as follows:

[0019]

[0020] The reaction principle for preparing the hydroxyl-terminated polyester is as follows: terephthalic acid and ethylene glycol are catalyzed by the catalyst antimony trioxide to form a polyester main chain through esterification and stepwise polycondensation reaction, in the reaction process, esterification reaction occurs between carboxyl groups and hydroxyl groups to generate ester bonds and gradually extend the chain segments, and finally a linear polyester structure with hydroxyl groups as end groups is formed to obtain the hydroxyl-terminated polyester.

[0021] Further, the post-treatment includes: after the polycondensation is completed, the temperature of the reaction kettle is reduced to 100℃, vacuum is continued to be applied to maintain the original vacuum degree and stirring is continued for 30-60min, then the vacuum is stopped and dry nitrogen is used for replacement for 2 times, and the temperature is maintained at 80-100℃ under the protection of nitrogen to discharge, and the modified polyester is obtained after sealing and packaging.

[0022] Further, in step S2, the amount ratio of the hydroxyl-terminated polyester, p-toluenesulfonic acid, the modified chain extender and the end-capping agent is 8-10g:0.3-0.5g:2-3g:0.5-0.8g, wherein the end-capping agent is 2-amino-1H-imidazole-4-carboxylic acid, and the post-treatment includes: after the reaction is completed, the kettle temperature is reduced to 90-100℃, nitrogen protection is maintained, a vacuum pump is started to apply vacuum for 30-45min, the vacuum degree is maintained at 100-120Pa, after the vacuum is stopped, dry nitrogen is introduced for replacement for 2-3 times, and hot filtration is performed through a 100-200 mesh screen at 90-100℃, after the filtration is completed, the temperature is maintained at 80-100℃ under the protection of nitrogen to discharge, and the modified polyester is obtained after sealing and packaging.

[0023] Further, in step S2, the preparation method of the modified chain extender includes the following steps:

[0024] A1, the graphene oxide dispersion liquid, anhydrous ethanol and deionized water are added into a reaction kettle, the pH of the reaction system is adjusted to 4-5 using acetic acid, then the temperature of the reaction kettle is raised to 40-60℃, and the reaction is stirred for 4-6h, and then the modified graphene is obtained by post-treatment;

[0025] A2, the modified graphite blank is calcined in a muffle furnace to obtain the composite graphene;

[0026] A3, the composite graphene, anhydrous ethanol and deionized water are added into a reaction kettle, nitrogen is introduced for protection, then the temperature of the reaction kettle is raised to 40-60℃, and the reaction is stirred for 10-15min, then 4-trimethoxysilyl butyric acid is added into the reaction kettle, and the reaction is stirred for 1-2h, and then the modified chain extender is obtained by post-treatment.

[0027] The reaction principle for preparing the modified chain extender is as follows: the hydrolysis and condensation reaction of tetrabutyl titanate and the oxygen-containing functional groups such as carboxyl and hydroxyl on the surface of graphene oxide occurs to form Ti-O-C or Ti-O-Ti bonds, thereby realizing the chemical bonding of titanium elements on the surface of graphene and obtaining the modified graphene; the high-temperature calcination in an air atmosphere promotes the crystallization reaction of the titanium component of the modified graphene to generate an inorganic phase and adhere to the surface of graphene, thereby obtaining the composite graphene; the 4-trimethoxysilyl butyric acid is hydrolyzed to generate silanol in an alcohol-water system, and then the condensation reaction of the silanol with the titanium dioxide component on the composite graphene occurs to realize the carboxyl functional modification, and finally the modified chain extender is prepared.

[0028] Further, in step A1, the amount ratio of the graphene oxide dispersion liquid, anhydrous ethanol and deionized water is 2-3mL:20-30mL:10-12mL, wherein the graphene oxide dispersion liquid is obtained by mixing graphene oxide and tetrabutyl titanate at an amount ratio of 1g:2-3mL, and the post-treatment includes: after the reaction is completed, the temperature of the reaction kettle is reduced to room temperature, the reaction liquid is filtered to collect the filter cake, the filter cake is washed with anhydrous ethanol and deionized water for 3-5 times, then the filter cake is transferred to a drying box with a temperature of 80℃, and vacuum drying is performed until the weight is constant, thereby obtaining the modified graphene;

[0029] Further, the calcination operation is as follows: the modified graphene is added into a muffle furnace with a temperature of 500℃, and calcination is performed in an air atmosphere for 4-6h, thereby obtaining the composite graphene;

[0030] Further, in step A3, the amount ratio of the composite graphene, anhydrous ethanol, deionized water and 4-trimethoxysilyl butyric acid is 8-9g:20-30mL:10-12mL:3-4g, and the post-treatment includes: after the reaction is completed, the temperature of the reaction kettle is reduced to room temperature, the reaction liquid is filtered to collect the filter cake, the filter cake is washed with anhydrous ethanol and deionized water for 3-5 times, then the filter cake is transferred to a drying box with a temperature of 80℃, and vacuum drying is performed until the weight is constant, thereby obtaining the modified chain extender.

[0031] Further, the auxiliary materials include the following raw material composition by weight: 3-5 parts of a thermal stabilizer, 4-6 parts of a lubricant, and 4-6 parts of an antioxidant, wherein the thermal stabilizer is one or both of dibutyltin dilaurate and epoxidized soybean oil; the lubricant is one or both of calcium stearate and polyethylene wax; and the antioxidant is one or both of triphenyl phosphite and dilauryl sulfide.

[0032] Further, the eight temperature zones of the twin-screw extruder from the feeding port to the discharging port are 280℃, 280℃, 285℃, 295℃, 295℃, 300℃, and 300℃, respectively, the main motor speed of the twin-screw extruder is 80-120rpm, and the pressure is 100-150bar.

[0033] Further, in step S3, the orifice of the spinneret is circular, the mesh number is 36, the hole diameter is 0.2mm, and the spinning pressure is 100bar; the cold air is air, the relative humidity is 30-50%, the temperature is 20-30℃, and the flow rate is maintained at 5-10m / s.

[0034] Further, in step S4, the preparation method of the antibacterial polyester fiber includes the following steps:

[0035] B1, zinc nitrate hexahydrate, methanol and polyester fiber are added to an ultrasonic generator, and after ultrasonic treatment at room temperature for 30-40min, the mixture is left to stand for 10-12h, and the modified polyester fiber is obtained after post-treatment;

[0036] B2, the modified polyester fiber, silver nitrate solution and polyvinyl alcohol are added to a reaction kettle, the temperature of the reaction kettle is increased to 40-50℃, and after stirring for 10-15min, sodium borohydride is added to the reaction kettle, and the mixture is kept at temperature for 30-40min, and the antibacterial polyester fiber is obtained after post-treatment.

[0037] The reaction principle for preparing the antibacterial polyester fiber is as follows: during the ultrasonic treatment of the zinc nitrate hexahydrate and methanol system, Zn 2+ forms a coordination structure with the imidazole structure organic ligand introduced on the polyester fiber, thereby generating a ZIF-8 structure in situ on the fiber surface, then the modified fiber further reacts with silver nitrate and polyvinyl alcohol, the amino groups on the fiber surface attract and coordinate with Ag + , and the silver ions are stably loaded on the surface, and under the action of sodium borohydride, the adsorbed Ag + is reduced in situ to generate silver nanoparticles, which are fixed in the fiber structure, and finally the antibacterial polyester fiber is prepared.

[0038] Further, in step B1, the amount ratio of zinc nitrate hexahydrate, methanol and polyester fiber is 1-2g:10mL:1g, and the post-treatment comprises: after the reaction is completed, the temperature of the reaction kettle is reduced to room temperature, the reaction liquid is filtered to collect the fiber material, the fiber material is washed with anhydrous ethanol and deionized water for 3-5 times, then the fiber material is transferred to a drying box with a temperature of 80 DEG C, and vacuum drying is performed until the weight is constant, to obtain the modified polyester fiber.

[0039] Further, in step B2, the amount ratio of the modified polyester fiber, silver nitrate solution, polyvinyl alcohol and sodium borohydride is 5-6g:15-20mL:0.5-0.8g:1-2g, the concentration of the silver nitrate solution is 0.2-0.3mol / L, and the post-treatment comprises: after the reaction is completed, the temperature of the reaction kettle is reduced to room temperature, the reaction liquid is filtered to collect the fiber material, the fiber material is washed with anhydrous ethanol and deionized water for 3-5 times, then the fiber material is transferred to a drying box with a temperature of 80 DEG C, and vacuum drying is performed until the weight is constant, to obtain the antibacterial polyester fiber.

[0040] The application further discloses an antibacterial and mildew-proof polyester long fiber prepared by the preparation method.

[0041] The application has the following advantages:

[0042] 1. The application introduces imidazole functional groups into polyester molecular chains to provide chemical basis for the directional combination of subsequent functional components, then utilizes the coordination of imidazole structure and Zn²⁺ under ultrasonic conditions to generate ZIF-8 structure in situ on the fiber surface, and constructs a stable metal organic framework, which not only significantly improves the specific surface area and reactivity of the fiber surface, but also endows the fiber with good zinc ion slow-release antibacterial function, on the basis of which, the fiber further undergoes coordination reaction with silver ions, silver nanoparticles are generated and firmly loaded on the fiber surface through the adsorption and fixation of amino groups to Ag⁺ and the in-situ reduction of sodium borohydride, and the antibacterial effect is further enhanced, and the whole preparation process realizes the organic cooperation among imidazole, ZIF-8 and silver nanoparticles, constructs a stable and efficient composite antibacterial system, and makes the antibacterial components uniformly distributed and not easy to fall off, thereby significantly improving the antibacterial durability and mildew-proof performance of the fiber.

[0043] 2、The ZIF-8 structure introduced on the surface of the fiber not only endows the fiber with antibacterial performance, but also has excellent ultraviolet absorption capacity; the metal organic framework structure of ZIF-8 can effectively absorb UV-A and UV-B band ultraviolet rays, so that the harmful radiation is shielded; meanwhile, the application further introduces a titanium dioxide (TiO2) component; as a commonly used inorganic ultraviolet absorbing material, TiO2 has excellent ultraviolet scattering and reflection performance, can inhibit ultraviolet rays from penetrating in a wide wavelength range, and further enhances the protection effect; in addition, the silver nanoparticles loaded on the surface of the fiber also have scattering effect on part of the ultraviolet band; the three form a synergistic action mechanism at the material level: ZIF-8 dominates ultraviolet absorption, TiO2 strengthens scattering and shielding, and silver nanoparticles supplement dispersion reflection, so that efficient ultraviolet protection of multiple dimensions and multiple mechanisms is realized; the above functional components are attached to the surface layer of the fiber through a stable chemical method, so that the durability and use stability are ensured, and the ultraviolet resistance of the material is significantly improved.

[0044] 3、The application also activates the surface of the substrate through a pretreatment means, introduces reactive functional groups such as hydroxyl and carboxyl, enhances the binding activity between the functional material and the fiber substrate, and forms a stable chemical or physical bonding interface between the functional components and the fiber substrate; in the introduction process of the functional material, ZIF-8, TiO2 or nanosilver and other functional components are generated or embedded in situ on the surface of the fiber by using sol-gel, self-assembly or in-situ growth methods, so that a dense, uniform and firm functional layer is formed; meanwhile, the bonding stability is further improved through a crosslinking agent, a coupling agent or a heat curing method, so that the functional layer is not easy to peel off or fall off when subjected to water washing, friction and detergent, compared with the traditional physical adsorption or simple coating method, the composite fixation mechanism significantly enhances the overall structural stability of the material system, so that excellent water washing durability is endowed, and the function is ensured to be long-term maintained without attenuation. DETAILED DESCRIPTION

[0045] The technical solutions of the application will be described below in conjunction with the embodiments, obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the application.

[0046] In the application, the calcium stearate used is purchased from Shanghai Maikelin Biochemical Technology Co., Ltd., and the brand is C805417; the graphene oxide is purchased from Shanghai Maikelin Biochemical Technology Co., Ltd., and the brand is G768901.

[0047] Example 1

[0048] The embodiment provides a preparation method of a modified chain extender for preparing antibacterial and mildew-proof polyester long fibers, and comprises the following steps:

[0049] Step I, preparing modified graphene

[0050] Taking: 10.0g of graphene oxide and 20.0mL of tetrabutyl titanate are mixed to obtain a graphene oxide dispersion liquid;

[0051] Taking: 20.0mL of the graphene oxide dispersion liquid, 200.0mL of anhydrous ethanol and 100.0mL of deionized water are added into a reaction kettle, the pH value of the reaction system is adjusted to 4 by using acetic acid, the temperature of the reaction kettle is increased to 40 DEG C, and the temperature is kept for 4h, after the reaction is completed, the temperature of the reaction kettle is reduced to room temperature, the reaction liquid is filtered, the filter cake is collected, the filter cake is washed three times by using anhydrous ethanol and deionized water, the filter cake is transferred to a drying box with a temperature of 80 DEG C, and vacuum drying is performed until the weight is constant, and the modified graphene is obtained.

[0052] Step II, preparing composite graphene

[0053] Taking: 10.0g of the modified graphene is added into a muffle furnace with a temperature of 500 DEG C, and calcination is performed under the atmosphere of air for 4h, and the composite graphene is obtained.

[0054] Step III, preparing a modified chain extender

[0055] Taking: 8.0g of the composite graphene, 20.0mL of anhydrous ethanol and 10.0mL of deionized water are added into a reaction kettle, nitrogen is introduced for protection, the temperature of the reaction kettle is increased to 40 DEG C, and the temperature is kept for 10min, 3.0g of 4-trimethoxysilyl butyric acid is added into the reaction kettle, the temperature is kept for 1h, after the reaction is completed, the temperature of the reaction kettle is reduced to room temperature, the reaction liquid is filtered, the filter cake is collected, the filter cake is washed three times by using anhydrous ethanol and deionized water, the filter cake is transferred to a drying box with a temperature of 80 DEG C, and vacuum drying is performed until the weight is constant, and the modified chain extender is obtained.

[0056] Embodiment 2

[0057] The embodiment provides a preparation method of a modified chain extender for preparing antibacterial and mildew-proof polyester long fibers, and comprises the following steps:

[0058] Step I, preparing modified graphene

[0059] Taking: 10.0g of graphene oxide and 30.0mL of tetrabutyl titanate are mixed to obtain a graphene oxide dispersion liquid;

[0060] Weighing: 30.0 mL of graphene oxide dispersion, 300.0 mL of anhydrous ethanol and 120.0 mL of deionized water are added to the reaction kettle, the pH of the reaction system is adjusted to 5 using acetic acid, and then the temperature of the reaction kettle is raised to 60℃ and stirred for 6h. After the reaction is completed, the temperature of the reaction kettle is reduced to room temperature, the reaction solution is filtered, the filter cake is washed with anhydrous ethanol and deionized water for 5 times, and then the filter cake is transferred to a drying oven at 80℃, and vacuum dried to constant weight to obtain modified graphene.

[0061] Step II, preparation of composite graphene

[0062] Weighing: 10.0 g of modified graphene is added to a muffle furnace at a temperature of 500℃ and calcined in an air atmosphere for 6h to obtain composite graphene.

[0063] Step III, preparation of modified chain extender

[0064] Weighing: 9.0 g of composite graphene, 30.0 mL of anhydrous ethanol and 12.0 mL of deionized water are added to the reaction kettle, and then nitrogen is introduced for protection. The temperature of the reaction kettle is raised to 60℃ and stirred for 15min, then 4.0 g of 4-trimethoxysilyl butyric acid is added to the reaction kettle, and stirred for 2h. After the reaction is completed, the temperature of the reaction kettle is reduced to room temperature, the reaction solution is filtered, the filter cake is washed with anhydrous ethanol and deionized water for 5 times, and then the filter cake is transferred to a drying oven at 80℃, and vacuum dried to constant weight to obtain a modified chain extender.

[0065] Example 3

[0066] The present embodiment provides a preparation method of a modified chain extender for preparing an antibacterial and mildew-proof polyester long fiber, comprising the following steps:

[0067] Step I, preparation of modified graphene

[0068] Weighing: 10.0 g of graphene oxide and 25.0 mL of tetrabutyl titanate are mixed to obtain a graphene oxide dispersion;

[0069] Weighing: 25.0 mL of graphene oxide dispersion, 250.0 mL of anhydrous ethanol and 100.0 mL of deionized water are added to the reaction kettle, the pH of the reaction system is adjusted to 4 using acetic acid, and then the temperature of the reaction kettle is raised to 60℃ and stirred for 5h. After the reaction is completed, the temperature of the reaction kettle is reduced to room temperature, the reaction solution is filtered, the filter cake is washed with anhydrous ethanol and deionized water for 4 times, and then the filter cake is transferred to a drying oven at 80℃, and vacuum dried to constant weight to obtain modified graphene.

[0070] Step II, preparation of composite graphene

[0071] Weighing: 10.0 g of modified graphene is added to a muffle furnace with a temperature of 500 ℃, and calcined for 6 h in an atmosphere of air to obtain composite graphene.

[0072] Step III, preparation of modified chain extender

[0073] Weighing: 8.0 g of composite graphene, 25.0 mL of anhydrous ethanol and 12.0 mL of deionized water are added to the reaction kettle, and after nitrogen protection, the temperature of the reaction kettle is increased to 50 ℃, and after 12 min of insulation stirring, 3.6 g of 4-trimethoxysilyl butyric acid is added to the reaction kettle, and the temperature is kept for 2 h. After the reaction is completed, the temperature of the reaction kettle is reduced to room temperature, the reaction liquid is filtered to collect the filter cake, the filter cake is washed with anhydrous ethanol and deionized water for 4 times, and then the filter cake is transferred to a drying box with a temperature of 80 ℃, and vacuum dried to constant weight to obtain a modified chain extender.

[0074] Example 4

[0075] The present embodiment provides a preparation method of modified polyester for preparing antibacterial and mildew-proof polyester long fibers, comprising the following steps:

[0076] Step ①, preparation of hydroxyl-terminated polyester

[0077] Weighing: 10.0 g of terephthalic acid, 0.03 g of antimony trioxide and 1.1 times of the molar amount of ethylene glycol in the reaction system are added to the reaction kettle, the temperature of the reaction kettle is increased to 220 ℃, and after 2 h of insulation reaction, the temperature of the reaction kettle is increased to 260 ℃ and the reaction kettle is vacuum treated, the internal gas pressure of the reaction kettle is reduced to 120 Pa within 30 min, and the temperature is kept for 40 min. After the condensation polymerization is completed, the temperature of the reaction kettle is reduced to 100 ℃, the vacuum is continued to maintain the original vacuum degree and the stirring is continued for 30 min, then the vacuum is stopped and the nitrogen gas is replaced for 2 times, and the temperature is maintained at 80 ℃ under the protection of nitrogen to discharge, and sealed packaging to obtain a hydroxyl-terminated polyester.

[0078] Step ②, preparation of modified polyester

[0079] Weighing: 8.0 g of hydroxyl-terminated polyester and 0.3 g of p-toluene sulfonic acid are added to the reaction kettle, and after nitrogen protection, the temperature of the reaction kettle is increased to 130 ℃ and 2.0 g of modified chain extender prepared in Example 1 is added to the reaction kettle, and after 1 h of insulation reaction, 0.5 g of 2-amino-1H-imidazole-4-carboxylic acid is added to the reaction kettle, and the temperature is kept for 30 min. After the reaction is completed, the temperature of the kettle is reduced to 90 ℃, the nitrogen protection is kept, the vacuum pump is started to vacuum for 30 min, the vacuum degree is maintained at 100 Pa, the vacuum is stopped, the dry nitrogen is replaced for 2 times, and the temperature is maintained at 80 ℃ under the protection of nitrogen to discharge, and sealed packaging to obtain a modified polyester.

[0080] Example 5

[0081] The present embodiment provides a method for preparing a modified polyester for preparing an antibacterial and mildew-proof polyester long fiber, comprising the following steps:

[0082] Step 1, preparing a hydroxyl-terminated polyester

[0083] Weighing: 12.0 g of terephthalic acid, 0.04 g of antimony trioxide, and 1.2 times the molar amount of ethylene glycol in the reaction system are added to the reaction kettle. The temperature of the reaction kettle is raised to 240°C, and after 3 hours of heat preservation reaction, the temperature of the reaction kettle is raised to 280°C and the reaction kettle is subjected to vacuum treatment. The internal gas pressure of the reaction kettle is reduced to 120 Pa within 45 min, and the temperature is maintained for 60 min. After the completion of the condensation reaction, the temperature of the reaction kettle is reduced to 100°C, and the vacuum is maintained and the stirring is continued for 60 min. Then the vacuum is stopped and the nitrogen gas is replaced twice, and the temperature is maintained at 100°C under the protection of nitrogen. The product is discharged, sealed and packaged to obtain the hydroxyl-terminated polyester.

[0084] Step 2, preparing a modified polyester

[0085] Weighing: 10.0 g of hydroxyl-terminated polyester and 0.5 g of p-toluene sulfonic acid are added to the reaction kettle. After the nitrogen protection, the temperature of the reaction kettle is raised to 160°C, and 3.0 g of the modified chain extender prepared in Example 2 is added to the reaction kettle. After 2 hours of heat preservation reaction, 0.8 g of 2-amino-1H-imidazole-4-carboxylic acid is added to the reaction kettle, and the reaction is maintained for 40 min. After the reaction is completed, the kettle temperature is reduced to 100°C, and the nitrogen protection is maintained. The vacuum pump is started to vacuum for 45 min, and the vacuum degree is maintained at 120 Pa. After the vacuum is stopped, dry nitrogen is introduced to replace it three times, and the product is filtered through a 200 mesh sieve at 100°C. After the filtration is completed, the temperature is maintained at 100°C under the protection of nitrogen, and the product is discharged and sealed for packaging to obtain the modified polyester.

[0086] Example 6

[0087] The present embodiment provides a method for preparing a modified polyester for preparing an antibacterial and mildew-proof polyester long fiber, comprising the following steps:

[0088] Step 1, preparing a hydroxyl-terminated polyester

[0089] Weighing: 12.0 g of terephthalic acid, 0.04 g of antimony trioxide and 1.2 times the molar amount of ethylene glycol in the carboxyl group of the reaction system into the reaction kettle, the temperature of the reaction kettle is raised to 230 DEG C, and after 3 h of heat preservation reaction, the temperature of the reaction kettle is raised to 270 DEG C and the reaction kettle is vacuumized, the internal gas pressure of the reaction kettle is reduced to 100 Pa within 40 min, and the heat preservation reaction is carried out for 50 min, after the completion of the polycondensation, the temperature of the reaction kettle is reduced to 100 DEG C, the vacuum is maintained and the stirring is continued for 45 min, then the vacuum is stopped and the dry nitrogen is replaced for 2 times, and the temperature is maintained at 90 DEG C under the protection of nitrogen, the material is discharged, sealed and packaged, and the hydroxyl-terminated polyester is obtained.

[0090] Step 2, preparation of modified polyester

[0091] Weighing: 9.0 g of hydroxyl-terminated polyester and 0.4 g of p-toluene sulfonic acid into the reaction kettle, after the protection of nitrogen is introduced, the temperature of the reaction kettle is raised to 150 DEG C, and 2.4 g of modified chain extender prepared in Example 3 is added into the reaction kettle, after 2 h of heat preservation reaction, 0.6 g of 2-amino-1H-imidazole-4-carboxylic acid is added into the reaction kettle, and the heat preservation reaction is carried out for 36 min, after the completion of the reaction, the kettle temperature is reduced to 90 DEG C, the nitrogen protection is maintained, the vacuum pump is started to vacuum for 36 min, the vacuum degree is maintained at 120 Pa, after the vacuum is stopped, the dry nitrogen is introduced to replace for 3 times, and the hot filtration is carried out through a 150 mesh screen at 96 DEG C, after the filtration is completed, the temperature is maintained at 90 DEG C under the protection of nitrogen, the material is discharged, sealed and packaged, and the modified polyester is obtained.

[0092] Example 7

[0093] The present embodiment provides a method for preparing an antibacterial and mildew-proof polyester fiber, comprising the following steps:

[0094] Step 1, preparation of polyester fiber

[0095] According to the weight parts, 80 parts of modified polyester prepared in Example 4, 3 parts of dibutyltin dilaurate, 4 parts of calcium stearate and 4 parts of triphenyl phosphite are added into the twin-screw extruder, the temperature of the eight temperature zones of the twin-screw extruder from the feeding port to the discharging port is 280 DEG C, 280 DEG C, 285 DEG C, 295 DEG C, 295 DEG C, 300 DEG C, 300 DEG C, respectively, the main machine rotation speed of the twin-screw extruder is 80 rpm, and the pressure is 100 bar, after the melt extrusion, the spinning pressure is 100 bar, the spinning plate with circular hole, the mesh number is 36, and the hole diameter is 0.2 mm, and after the air drying with the flow rate of 5 m / s, the relative humidity of 30% and the temperature of 20 DEG C, the polyester fiber is obtained.

[0096] Step 2, preparation of modified polyester fiber

[0097] Weighing: 10.0 g of zinc nitrate hexahydrate, 100.0 mL of methanol and 10.0 g of polyester fiber are added to the ultrasonic generator, and after ultrasonic treatment at room temperature for 30 min, the reaction is allowed to stand for 10 h. After the reaction is completed, the temperature of the reaction kettle is reduced to room temperature, the reaction liquid is filtered to collect the fiber material, and the fiber material is washed with anhydrous ethanol and deionized water for 3 times. Then, the fiber material is transferred to a drying box with a temperature of 80°C, and vacuum dried to constant weight to obtain the modified polyester fiber.

[0098] Step three, preparation of antibacterial polyester fiber

[0099] Weighing: 5.0 g of modified polyester fiber, 15.0 mL of 0.2 mol / L silver nitrate solution and 0.5 g of polyvinyl alcohol are added to the reaction kettle, and the temperature of the reaction kettle is increased to 40°C. After stirring for 10 min, 1.0 g of sodium borohydride is added to the reaction kettle, and the reaction is allowed to stand for 30 min. After the reaction is completed, the temperature of the reaction kettle is reduced to room temperature, the reaction liquid is filtered to collect the fiber material, and the fiber material is washed with anhydrous ethanol and deionized water for 3 times. Then, the fiber material is transferred to a drying box with a temperature of 80°C, and vacuum dried to constant weight to obtain the antibacterial polyester fiber.

[0100] Example 8

[0101] The present embodiment provides a method for preparing antibacterial and mildew-proof polyester long fiber, comprising the following steps:

[0102] Step one, preparation of polyester fiber

[0103] According to the weight parts, 100 parts of the modified polyester prepared in Example 5, 4 parts of dibutyltin dilaurate, 5 parts of calcium stearate and 5 parts of triphenyl phosphite are added to the twin-screw extruder. The temperatures of the eight temperature zones of the twin-screw extruder from the feeding port to the discharging port are 280°C, 280, 285°C, 295°C, 295°C, 300°C, 300°C, respectively. The main machine speed of the twin-screw extruder is 120 rpm, and the pressure is 150 bar. After melt extrusion, the fiber is obtained by using a spinning nozzle with a circular shape, a mesh number of 36 and a pore size of 0.2 mm at a spinning pressure of 100 bar, and then dried by air with a flow rate of 10 m / s, a relative humidity of 50% and a temperature of 30°C. The modified polyester fiber is obtained.

[0104] Step two, preparation of modified polyester fiber

[0105] Take: 20.0 g of zinc nitrate hexahydrate, 100.0 mL of methanol and 10.0 g of polyester fiber into the ultrasonic generator, ultrasonic at room temperature for 40 min, and stand for 12 h after the reaction is completed, the temperature of the reactor is reduced to room temperature, filter the reaction solution to collect the fiber material, wash the fiber material with anhydrous ethanol and deionized water for 5 times, then transfer the fiber material to a drying oven with a temperature of 80℃, and vacuum dry to constant weight to obtain modified polyester fiber.

[0106] Step three, preparation of antibacterial polyester fiber

[0107] Take: 6.0 g of modified polyester fiber, 20.0 mL of 0.3 mol / L silver nitrate solution and 0.8 g of polyvinyl alcohol into the reactor, the temperature of the reactor is raised to 50℃, and after stirring for 15 min, 2.0 g of sodium borohydride is added to the reactor, and the reaction is carried out for 40 min. After the reaction is completed, the temperature of the reactor is reduced to room temperature, the reaction solution is filtered to collect the fiber material, the fiber material is washed with anhydrous ethanol and deionized water for 5 times, then the fiber material is transferred to a drying oven with a temperature of 80℃, and vacuum dried to constant weight to obtain antibacterial polyester fiber.

[0108] Example 9

[0109] The present embodiment provides a method for preparing antibacterial and mildew-proof polyester long fiber, comprising the following steps:

[0110] Step one, preparation of polyester fiber

[0111] Take: 96 parts of modified polyester prepared in Example 6, 4 parts of dibutyltin dilaurate, 5 parts of calcium stearate and 5 parts of triphenyl phosphite by weight into a twin-screw extruder, the temperature of the eight temperature zones of the twin-screw extruder from the feeding port to the discharge port is 280℃, 280, 285℃, 295℃, 295℃, 300℃, 300℃, respectively, the main machine speed of the twin-screw extruder is 100 pm, and the pressure is 120 bar. After melt extrusion, pass through a spinneret plate with a circular shape, a mesh number of 36 and a pore diameter of 0.2 mm at a spinning pressure of 100 bar, and dry in air with a flow rate of 8 m / s, a relative humidity of 40% and a temperature of 24℃, polyester fiber is obtained.

[0112] Step two, preparation of modified polyester fiber

[0113] Weighing: 16.0 g of zinc nitrate hexahydrate, 100.0 mL of methanol and 10.0 g of polyester fiber are added to the ultrasonic generator, and after ultrasonic treatment at room temperature for 36 min, the reaction is allowed to stand for 12 h. After the reaction is completed, the temperature of the reaction kettle is reduced to room temperature, the reaction solution is filtered to collect the fiber material, and the fiber material is washed with anhydrous ethanol and deionized water for 4 times. Then, the fiber material is transferred to a drying box with a temperature of 80℃, and vacuum dried to constant weight to obtain the modified polyester fiber.

[0114] Step three, preparation of antibacterial polyester fiber

[0115] Weighing: 6.0 g of modified polyester fiber, 18.0 mL of 0.3 mol / L silver nitrate solution and 0.6 g of polyvinyl alcohol are added to the reaction kettle, and the temperature of the reaction kettle is increased to 45℃. After stirring for 12 min, 1.6 g of sodium borohydride is added to the reaction kettle, and the reaction is allowed to stand for 36 min. After the reaction is completed, the temperature of the reaction kettle is reduced to room temperature, the reaction solution is filtered to collect the fiber material, and the fiber material is washed with anhydrous ethanol and deionized water for 4 times. Then, the fiber material is transferred to a drying box with a temperature of 80℃, and vacuum dried to constant weight to obtain the antibacterial polyester fiber.

[0116] Comparative Example 1

[0117] The difference between this comparative example and Example 9 is that the modified polyester used in the preparation process cancels the addition of the modified chain extender in step II, and uses modified graphene instead of composite graphene in an equivalent amount in step III.

[0118] Comparative Example 2

[0119] The difference between this comparative example and Example 9 is that the modified polyester used in the preparation process cancels the addition of 2-amino-1H-imidazole-4-carboxylic acid in step ②.

[0120] Comparative Example 3

[0121] The difference between this comparative example and Example 9 is that the modified polyester used in the preparation process cancels the addition of the modified chain extender in step ②, and uses 4-trimethoxysilyl butyric acid instead of the modified chain extender in an equivalent amount.

[0122] Performance test:

[0123] The mold resistance grade of the antibacterial polyester fiber prepared in Examples 7-9 and Comparative Examples 1-3 is tested according to the standard GB / T 24346-2009 "Evaluation of Mold Resistance of Textiles".

[0124] The antibacterial rate of the antibacterial polyester fiber prepared in Examples 7-9 and Comparative Examples 1-3 is detected according to the standard GB / T 20944.3-2008 "Evaluation of Antibacterial Performance of Textiles Part 3: Oscillation Method", and the selected bacteria are Staphylococcus aureus and Candida albicans, respectively.

[0125] The ultraviolet protection factor of the antibacterial polyester fibers prepared in Examples 7-9 and Comparative Examples 1-3 was tested according to the standard GB / T 18830-2009 "Evaluation of Anti-Ultraviolet Performance of Textiles", and the specific data are shown in Table 1.

[0126] The antibacterial polyester fibers prepared in Example 9 and Comparative Examples 2-3 were subjected to cyclic water washing, and the mold resistance grade, bacteriostatic rate and ultraviolet protection factor were tested again according to GB / T 24346-2009, GB / T 20944.3-2008 and GB / T 18830-2009, and the specific data are shown in Table 2.

[0127] Table 1 - Performance test data table of the sample

[0128]

[0129] Table 2 - Performance test data of the sample after cyclic water washing

[0130]

[0131] Data analysis:

[0132] After comparing and analyzing the data in Table 1, it was found that the staphylococcus aureus killing rate of the antibacterial polyester fiber prepared by the present application was 99.8%, the candida albicans killing rate was 99.8%, the mold resistance grade was 0, and the ultraviolet protection factor was 51.

[0133] After comparing and analyzing the data in Table 2, it was found that the staphylococcus aureus killing rate of the antibacterial polyester fiber prepared by the present application was 99.2% after 100 times of washing, the candida albicans killing rate was 99.2%, the mold resistance grade was 0, and the ultraviolet protection factor was 44, which indicated that:

[0134] This scheme is based on the synergistic reaction and structural integration between multiple functional units to construct a composite polyester material with antibacterial function and structural stability. The technical core principle lies in realizing the organic integration between polyester chain structure, inorganic functional unit, coordination functional group and metal antibacterial component through multi-stage chemical coupling and interface regulation.

[0135] First, the carboxyl and hydroxyl functional groups on the surface of graphene undergo chemical condensation reaction with metal titanium source to introduce Ti-O-C, Ti-O-Ti covalent bonds, and realize the construction of stable inorganic functional units on the surface of carbon materials. This process not only improves the interface activity and dispersibility of graphene, but also provides rich anchoring sites for subsequent structure grafting and functional modification. In the subsequent treatment process, the titanium component is crystallized to form a nanoscale inorganic phase, which forms a strong coupling interface with graphene, and endows the material with excellent thermal stability and carrier capacity.

[0136] At the polymer level, the main chain is constructed by esterification between carboxyl and hydroxyl, and a chain extension structure with functional activity is introduced, which introduces active points that can be further reacted in the main chain, wherein the introduction of imidazole structure units has good metal ion coordination ability, which can form stable coordination structures with Zn²⁺, Ag⁺, etc.

[0137] In this system, the ZIF-8 structure is formed by self-assembly of imidazole ligand and zinc ion, which introduces porosity, ion release and antibacterial function to the material, and the further loading and in-situ reduction of silver ion realizes the stable deposition of silver nanoparticles through coordination adsorption and reduction nucleation process of amino functional groups, which provides the material with broad-spectrum antibacterial ability.

[0138] Finally, the stable grafting of inorganic structure in the organic main chain is realized through chemical bonding and interface fusion, which improves the composite stability; the controllable coordination reaction guided by functional groups realizes the precise construction of functional units at specified sites; the interaction of nanostructure and molecular structure at different levels constructs a multi-scale synergistic construction mechanism to enhance the material performance, so as to realize the synergistic enhancement and functional coupling of material structure through the coupling mechanism of the three types of structure units of "organic-inorganic-metal" at the molecular scale, and finally a high-performance antibacterial polyester fiber is prepared.

[0139] The preferred embodiments disclosed above are only used to help explain the present application. The preferred embodiments do not describe all the details, nor limit the application to the specific embodiments. Obviously, many modifications and variations can be made according to the content of the present application. The present application is selected and described in detail, in order to better explain the principles and practical application of the present application, so that those skilled in the art can well understand and utilize the present application. The present application is limited by the claims and their full scope and equivalents.

Claims

1. A method for preparing an anti-bacterial and anti-mildew polyester filament, characterized in that, It comprises the following steps: S1, terephthalic acid and ethylene glycol as raw material vacuum polycondensation, preparation of hydroxyl-terminated polyester is obtained; S2, the hydroxyl-terminated polyester and p-toluene sulfonic acid is added to the reaction kettle, after the protection of nitrogen is imported, the reaction kettle temperature rises to 130-160℃ and the modified chain extender is added to the reaction kettle, after heat preservation reaction 1-2h, the end-capping agent is added to the reaction kettle, heat preservation reaction 30-40min, after treatment, the modified polyester is obtained; S3, according to the weight part, 80-100 parts of modified polyester and 10-16 parts of auxiliary materials are added into the double screw extruder, after melt extrusion, through the spinneret extrusion, it is transferred to the side blowing chamber, after air cooling solidification, the polyester fiber is obtained; S4, the surface of polyester fiber is modified with silver loaded MOFs structure, and the antibacterial polyester fiber is obtained.

2. The method for preparing antibacterial and mildew-resistant polyester long fibers according to claim 1, characterized in that, In step S1, the preparation method of hydroxyl-terminated polyester is as follows: terephthalic acid, antimony trioxide and calculated amount of ethylene glycol are added into the reaction kettle, the temperature of the reaction kettle is raised to 220-240℃, after heat preservation reaction for 2-3h, the temperature of the reaction kettle is raised to 260-280℃, and the reaction kettle is vacuum treated, the internal pressure of the reaction kettle is reduced to 100-120Pa within 30-45min, and heat preservation reaction is carried out for 40-60min, and the hydroxyl-terminated polyester is obtained after treatment; wherein the amount ratio of terephthalic acid and antimony trioxide is 10-12g:0.03-0.04g, and the amount of ethylene glycol is 1.1-1.2 times of the molar amount of carboxyl in the reaction system.

3. The method of claim 1, wherein the anti-bacterial and anti-mildew polyester filament is prepared by adding 0.1 to 0.5 parts by weight of the anti-bacterial and anti-mildew agent to 100 parts by weight of the polyester filament. In step S2, the amount ratio of the hydroxyl-terminated polyester, p-toluene sulfonic acid, modified chain extender and end-capping agent is 8-10g:0.3-0.5g:2-3g:0.5-0.8g, wherein the end-capping agent is 2-amino-1H-imidazole-4-carboxylic acid.

4. The method for preparing antibacterial and mildew-resistant polyester long fibers according to claim 1, characterized in that, In step S2, the preparation method of the modified chain extender comprises the following steps: A1, graphene oxide dispersion, anhydrous ethanol and deionized water are added into the reaction kettle, the pH of the reaction system is adjusted to 4-5 using acetic acid, then the temperature of the reaction kettle is raised to 40-60℃, and heat preservation stirring is carried out for 4-6h, then the modified graphene is obtained after treatment; A2, the modified graphene blank is calcined in a muffle furnace to obtain composite graphene; A3, the composite graphene, anhydrous ethanol and deionized water are added into the reaction kettle, after the protection of nitrogen is imported, the temperature of the reaction kettle is raised to 40-60℃, after heat preservation stirring for 10-15min, 4-trimethoxysilyl butyric acid is added into the reaction kettle, heat preservation stirring is carried out for 1-2h, and the modified chain extender is obtained after treatment.

5. The method for preparing an antibacterial and mildew-resistant polyester long fiber according to claim 4, characterized in that, In step A1, the amount ratio of the graphene oxide dispersion, anhydrous ethanol and deionized water is 2-3mL:20-30mL:10-12mL, wherein the graphene oxide dispersion is obtained by mixing graphene oxide and tetrabutyl titanate at a ratio of 1g:2-3mL; in step A3, the amount ratio of the composite graphene, anhydrous ethanol, deionized water and 4-trimethoxysilyl butyric acid is 8-9g:20-30mL:10-12mL:3-4g.

6. The method for preparing an antibacterial and mildew-resistant polyester long fiber according to claim 1, characterized in that, In step S4, the preparation method of the antibacterial polyester fiber comprises the following steps: B1, zinc nitrate hexahydrate, methanol and polyester fiber are added into an ultrasonic generator, and after ultrasonic treatment at room temperature for 30-40 min, they are left to stand for 10-12 h, and then post-treated to obtain modified polyester fiber; B2, the modified polyester fiber, silver nitrate solution and polyvinyl alcohol are added into a reaction kettle, the temperature of the reaction kettle is raised to 40-50 DEG C, and after stirring for 10-15 min, sodium borohydride is added into the reaction kettle, and the reaction is carried out for 30-40 min, and then post-treated to obtain antibacterial polyester fiber.

7. The method of claim 6, wherein the anti-mildew polyester filament is prepared by adding 0.1 to 0.3 parts by weight of the anti-mildew agent to 100 parts by weight of the polyester filament. In step B1, the amount ratio of zinc nitrate hexahydrate, methanol and polyester fiber is 1-2 g:10 mL:1 g; in step B2, the amount ratio of modified polyester fiber, silver nitrate solution, polyvinyl alcohol and sodium borohydride is 5-6 g:15-20 mL:0.5-0.8 g:1-2 g, and the concentration of silver nitrate solution is 0.2-0.3 mol / L.

8. A flame-retardant impact-resistant polycarbonate material characterized by, The flame-retardant impact-resistant polycarbonate material is prepared by the method for preparing a flame-retardant impact-resistant polycarbonate material according to any one of claims 1-7.

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