A process for preparing polyester fiber fabric by regenerating polyester waste bottle flakes

Abstract

The invention discloses a process for preparing polyester fiber fabric by regenerating polyester waste bottle flakes, belongs to the technical field of polyester fiber fabric processing, and is used to solve the technical problem that the moisture absorption and quick-drying performance and the friction and pilling resistance of polyester fiber fabric in the prior art need to be further improved; the invention comprises the following steps: adding polyester waste bottle flakes into a pulverizer, pulverizing, passing through a 60-mesh sieve to obtain polyester regenerated powder, and pretreating the polyester regenerated powder to obtain pretreated polyester powder; the invention uses modified polysiloxane to enhance copolyester containing nylon 6 and polyvinyl alcohol blocks to prepare composite polyester, and then uses polyvinyl alcohol as a pore-forming agent to prepare porous composite polyester fiber, which not only effectively improves the moisture absorption and quick-drying performance of polyester fiber fabric, enhances the wearing experience of polyester fiber fabric, but also improves the wear and pilling resistance of polyester fiber fabric.

Description

Technical Field

[0001] The invention relates to the technical field of polyester fiber fabric processing, and in particular to a process for preparing polyester fiber fabric by regenerating polyester waste bottle flakes. Background Art

[0002] The recycling of waste polyester bottle flakes is an important environmental protection and resource recycling process. As a recyclable resource, waste polyester bottle flakes can reduce dependence on primary petroleum resources and reduce resource consumption through recycling. The production of recycled polyester helps promote the development of the circular economy, forming a closed-loop economic model of "resources-products-recycled resources" and realizing the sustainable use of resources.

[0003] The prior art, an invention patent with publication number CN118109920A, discloses a method for preparing cool and elastic fabrics from regenerated polyester fiber filaments, which comprises adding a modifier to dolomite, shell powder, boron nitride and expanded perlite, grinding to obtain a nano-scale modified inorganic powder mixture, crushing and depolymerizing the polyester bottle, adding the nano-scale modified inorganic powder mixture and Artemisia annua powder, and then condensing to obtain regenerated polyester, melt-spinning the regenerated polyester to obtain regenerated polyester fiber fabrics, and spraying a finishing agent onto the regenerated polyester fiber fabrics to prepare cool and elastic fabrics.

[0004] However, traditional polyester fiber fabrics contain a large number of non-polar structures in polyester fiber molecules. The interaction between these structures and water molecules is weak, which makes it difficult for polyester fibers to absorb moisture. In addition, the surface of polyester fibers is smooth and lacks microstructures and gaps, which further limits their ability to adsorb moisture. Although the enhancement of inorganic particles can enhance the breathability of the material, the moisture absorption and quick-drying properties of polyester fiber fabrics cannot be effectively improved, which reduces the wearing experience of polyester fibers after sweating. Moreover, the anti-pilling performance of polyester fabrics during the friction process is poor, which makes it easy for wear and pilling to occur during wearing.

[0005] In view of the technical defects in this aspect, a solution is now proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a process for preparing polyester fiber fabrics by regenerating polyester waste bottle flakes, which is used to solve the technical problem in the prior art that the moisture absorption and quick-drying performance and the friction and anti-pilling performance of polyester fiber fabrics need to be further improved.

[0007] The purpose of the present invention can be achieved by the following technical scheme: A process for preparing polyester fiber fabric by regenerating polyester waste bottle flakes, comprising the following steps:

[0008] S1, adding polyester waste bottle pieces into a pulverizer, pulverizing, passing through a 60-mesh sieve, and obtaining polyester recycled powder;

[0009] S2, pre-treating the polyester recycled powder to obtain pre-treated polyester powder, and then alcoholyzing the pre-treated polyester powder to obtain an alcoholysis extract;

[0010] S3. Under nitrogen protection, the alcoholysis extract, 1,4-butenediol and the catalyst are mixed, the temperature of the reaction system is raised to 240-250°C after the reaction system is sealed, and the reaction is kept warm for 60-80 minutes, polyethylene glycol and nylon 6 are added to the reaction system, and the reaction is stirred for 20-30 minutes, and the reaction system is evacuated to a vacuum pressure of -0.1 MPa, and the reaction is kept warm. When the output power increases by 10-20% under constant stirring speed, post-treatment is performed to obtain copolyester;

[0011] The synthesis reaction equation of copolyester is:

[0012]

[0013] Where:

[0014] ;

[0015] .

[0016] The synthesis reaction mechanism of copolyester is:

[0017] During the reaction, under the action of high temperature and catalyst, the ester bonds on the alcoholysis extract molecules undergo ester exchange with the alcoholic hydroxyl groups on the 1,4-butenediol molecules, the hydroxyl functional groups of the polyethylene glycol or the amino and carboxyl functional groups on the nylon 6 molecules undergo esterification reaction with the alcoholysis extract or the alcoholysis monomer and the ester exchange product of 1,4-butenediol, the functional groups in the reaction system undergo esterification reaction to generate a part of the copolyester, and polyethylene glycol and nylon 6 blocks are introduced into the copolyester.

[0018] S4, reinforcing and modifying the copolyester with modified polysiloxane to prepare a composite polyester;

[0019] S5. The composite polyester is melt-spinned, stretched and impregnated to obtain composite polyester fibers, and then polyester fiber fabrics are prepared using the polyester fibers as raw materials.

[0020] Further, the modified polysiloxane is processed by the following steps:

[0021] B1. Under nitrogen protection, sodium p-aminobenzenesulfonate and tetrahydrofuran are mixed, the temperature of the reaction system is raised to 60-65° C., stirred until the system is dissolved, 3-isocyanatopropylmethyldiethoxysilane is added to the reaction system, the reaction is kept warm for 40-60 minutes, and post-processed to obtain modified sodium sulfonate;

[0022] The synthetic reaction formula of modified sodium sulfonate is:

[0023]

[0024] The synthetic reaction mechanism of modified sodium sulfonate is:

[0025] During the reaction, the amino group on the sodium p-aminobenzenesulfonate molecule condenses with the isocyanate group on the 3-isocyanatopropylmethyldiethoxysilane molecule, and the diethoxysilane is modified on the sodium benzenesulfonate molecule to prepare modified sodium sulfonate;

[0026] The mass spectrometry data of modified sodium sulfonate are: m / z: 412.1080 (100.0%), 413.1112 (16.2%),

[0027] 413.1069(5.1%),414.1038(4.5%),414.1058(3.3%),414.1121(1.2%),414.1137(1.2%).

[0028] B2. Mix modified sodium sulfonate, octamethylcyclotetrasiloxane, cyclotetradimethylsiloxane and xylene, add formic acid solution to the reaction system, seal the reaction system, increase the temperature of the reaction system to 110-120°C, keep the temperature for 4-5 hours, add 1,1,3,3-tetramethyldisiloxane to the reaction system, keep the temperature for 2-3 hours, and post-treat to obtain modified polysiloxane.

[0029] The synthetic reaction formula of modified polysiloxane is:

[0030]

[0031] Where:

[0032] .

[0033] The synthetic reaction mechanism of modified polysiloxane is:

[0034] During the reaction, under the action of high temperature and catalyst, the siloxane bonds on the modified sodium sulfonate molecules and octamethylcyclotetrasiloxane and cyclotetradimethylsiloxane are hydrolyzed to form siloxane chains with silanol activity, and then the silanols on the siloxane chains are condensed to form long polysiloxane chains containing sodium sulfonate and silicon hydrogen modification. 1,1,3,3-tetramethyldisiloxane is used as a capping agent and is hydrolyzed during the reaction to form dimethylsilanol as a chain terminator to form silicon hydrogen capping to prepare modified polysiloxane.

[0035] Further, in step S2, the alcoholysis extract is processed by the following steps:

[0036] A1. Add the polyester recycled powder into the pretreatment solution and stir. The temperature of the pretreatment solution is raised to 65-75°C and stirred for 50-60 minutes. The pretreatment polyester powder is obtained by post-treatment.

[0037] The reaction mechanism of pretreated polyester powder is:

[0038] During the treatment process, the sodium hydroxide, sodium dodecyl sulfate, ethanol and other components in the pretreatment solution work together to effectively remove impurities and pollutants on the surface of the polyester recycled powder, improve the cleanliness of the polyester powder, and prepare the pretreated polyester powder.

[0039] A2. Under nitrogen protection, pretreated polyester powder, ethylene glycol and catalyst are mixed, the reaction system is sealed and the temperature is raised to 180-200°C, the reaction is kept warm for 6-8 hours, and the alcoholysis extract is obtained by post-treatment.

[0040] The synthetic reaction formula of alcoholysis extract is:

[0041]

[0042] The synthetic reaction mechanism of alcoholysis extract is:

[0043] During the reaction, ethylene glycol is used as an alcoholysis agent and zinc acetate is used as a catalyst. The hydroxyl group of ethylene glycol reacts with the ester bond in the polyester powder, resulting in the breaking of the ester bond and the generation of new ester bonds and oligomers or monomers of ethylene glycol, thereby preparing an alcoholysis extract.

[0044] Furthermore, in step A1, the amount ratio of the polyester recycled powder and the pretreatment solution is 1g:7-9mL, the pretreatment solution is composed of sodium hydroxide, sodium dodecyl sulfate, polyethylene glycol 800, anhydrous ethanol and purified water in an amount ratio of 12-16g:3-5g:2-4g:60mL:50mL, and the post-treatment includes: after the reaction is completed, the temperature of the reaction system is lowered to room temperature, filtered, the filter cake is washed with 40vol% ethanol solution until neutral and then dried, the filter cake is transferred to a drying oven at a temperature of 70-80°C, and vacuum dried to constant weight to obtain pretreated polyester powder.

[0045] Furthermore, in step A2, the amount ratio of the pretreated polyester powder, ethylene glycol and catalyst is 10g:35-45mL:0.1g, the catalyst is zinc acetate, and the post-treatment includes: after the reaction is completed, the temperature of the reaction system is lowered to room temperature, a 3wt% sodium dodecyl sulfate aqueous solution is added to the reaction system, stirred and dispersed for 20-30min, filtered, the filter cake is washed with purified water 3 times and then dried, the filter cake is transferred to a drying oven at a temperature of 70-80°C, and vacuum dried to constant weight to obtain an alcoholysis extract.

[0046] Furthermore, in step S3, the weight ratio of the alcoholysis extract, 1,4-butene glycol, catalyst, polyethylene glycol and nylon 6 is 150-180:40-60:0.2-0.3:30-40:40-50, the catalyst is antimony trioxide, and the post-treatment includes: after the reaction is completed, under nitrogen protection, the reaction system is restored to normal pressure, and the material is discharged to obtain copolyester.

[0047] Furthermore, in step S4, the preparation method of the composite polyester is: mixing the copolyester, modified polysiloxane, polyvinyl alcohol, a catalyst and N-methylpyrrolidone, raising the temperature of the reaction system to 90-100° C., keeping the reaction temperature for 6-8 hours, and post-treating to obtain the composite polyester.

[0048] The synthetic reaction formula of composite polyester is:

[0049]

[0050] The synthetic reaction mechanism of composite polyester is:

[0051] During the reaction, the olefin double bonds on the copolyester molecules are used as reactive sites and undergo silylation with the silane-hydrogen sites on the polysiloxane molecules, so that the polysiloxane is embedded in the copolyester molecular chain to prepare a composite polyester.

[0052] Furthermore, the amount ratio of the copolyester, modified polysiloxane, polyvinyl alcohol, catalyst and N-methylpyrrolidone is 70-80g:15-17g:4-7g:0.2-0.3g:500-600mL, the catalyst is chloroplatinic acid, and the post-treatment includes: after the reaction is completed, the temperature of the reaction system is lowered to room temperature, anhydrous ethanol is added to the reaction system, filtered, the filter cake is washed with anhydrous ethanol 3 times and then dried, the filter cake is transferred to a drying oven at a temperature of 70-80°C, and vacuum dried to a water content of less than 0.1% to obtain a composite polyester.

[0053] Furthermore, in step B1, the dosage ratio of sodium p-aminobenzenesulfonate to 3-isocyanatopropylmethyldiethoxysilane is 1 mol:1 mol, and the dosage ratio of sodium p-aminobenzenesulfonate to tetrahydrofuran is 1 g:10-15 mL. The post-treatment includes: after the reaction is completed, distilling off tetrahydrofuran under reduced pressure to obtain modified sodium sulfonate.

[0054] Furthermore, in step B2, the amount ratio of the modified sodium sulfonate, octamethylcyclotetrasiloxane, cyclotetradimethylsiloxane, xylene, formic acid solution and 1,1,3,3-tetramethyldisiloxane is 3-5g:15-18g:6-7g:80-90mL:10-15mL:1.8-2.2g, the formic acid solution is composed of formic acid and purified water at 1g:2mL, and the post-treatment includes: after the reaction is completed, the temperature of the reaction system is lowered to room temperature, sodium hydroxide solution is added to the reaction system, the pH of the system is adjusted to 7, the liquid is allowed to stand, the organic phase is washed with purified water 3 times, and then dried for 2-3h, and the organic phase is transferred to a rotary evaporator with a water bath temperature of 70-80°C, and xylene is evaporated under reduced pressure to obtain a modified polysiloxane.

[0055] Further, the composite polyester fiber is processed by the following steps:

[0056] C1. Adding the composite polyester into a twin-screw extruder, extruding the composite polyester into a spinning machine through the twin-screw extruder, and stretching the composite polyester fiber precursor after melt spinning;

[0057] C2, placing the composite polyester fiber precursor in an impregnation solution at a temperature of 80-90° C., ultrasonically dispersing for 60-80 minutes, and post-treating to obtain a composite polyester fiber;

[0058] The synthetic reaction mechanism of composite polyester fiber is:

[0059] During the reaction process, 5wt% sodium dodecyl sulfate solution is used as the impregnating liquid, and ultrasonic dispersion is used to promote the mixing of the impregnating liquid and the composite polyester fiber precursor, so that the polyvinyl alcohol in the composite polyester fiber precursor molecules is dissolved and separated from the polyester fiber precursor molecules, forming a porous structure on the composite polyester fiber precursor, and preparing a composite polyester fiber.

[0060] C3. Blending the composite polyester fibers to obtain composite polyester yarns, and then weaving the composite polyester yarns to obtain polyester fiber fabrics.

[0061] Furthermore, in step C1, the temperatures of the six temperature zones of the twin-screw extruder from the feed end to the discharge end are 260°C, 265°C, 265°C, 265°C, 270°C, and 270°C, respectively, the main shaft speed of the twin-screw extruder is 15-18r / min, the spinning temperature of the melt spinning machine is 280-290°C, air cooling curing is adopted during melt spinning, the air cooling supply temperature is 35-45°C, the blowing rate is 0.6-0.8m / s, the stretching temperature is 80-90°C, and the stretching ratio is 1.5-1.8 times.

[0062] Furthermore, in step C2, the dosage ratio of the composite polyester fiber precursor and the impregnation liquid is 1g:20-30mL, the impregnation liquid is a 5wt% sodium dodecyl sulfate solution, and the post-treatment includes: after the reaction is completed, the polyester fiber precursor is taken out from the impregnation liquid, washed 3 times with purified water, and dried to obtain the composite polyester fiber.

[0063] Furthermore, in step C3, the linear density of the composite polyester yarn is 100-120D / 36F.

[0064] The present invention has the following beneficial effects:

[0065] 1. The polyester waste bottle flakes of the present invention are recycled to prepare polyester fiber fabrics. The polyester bottle flakes are used as raw materials. After being crushed, they are washed with a pretreatment solution to improve the cleanliness of polyester powder, reduce the influence of impurities adhering to the polyester powder on alcoholysis, help the smooth progress of subsequent alcoholysis reaction, and reduce the occurrence of side reactions. Polyethylene glycol and nylon 6 are used as reinforcing chains to reinforce the alcoholysis monomer to prepare copolyester. Both polyethylene glycol and nylon 6 have good hydrophilicity and cooperate with each other to improve the hygroscopicity of the polyester fiber fabric, so that the fabric absorbs moisture on one side and quickly transfers it to the other side through the hydrophilic channel inside the fiber, thereby improving the moisture absorption and quick-drying performance of the polyester fiber fabric.

[0066] 2. The polyester waste bottle flakes of the present invention are recycled to prepare polyester fiber fabrics. The amide bonds in the molecular structure of nylon 6 have higher bond energy and show high wear resistance and are not easy to break. The introduction of nylon 6 into the copolyester can improve the wear resistance of the copolyester fiber and make it more durable. The modified polysiloxane is compounded with the copolyester, and the silicon hydrogen on the modified polysiloxane chain molecule and the olefin double bond on the copolyester molecule undergo silicon hydrogen addition, thereby improving the intermolecular crosslinking degree of the composite polyester and increasing the interaction force between the fibers, so that the fibers can better absorb and disperse energy when subjected to external forces, avoiding breakage caused by stress concentration, and making the polyester fiber fabric more wear-resistant and not easy to pill.

[0067] 3. The polyester waste bottle flakes of the present invention are recycled to prepare polyester fiber fabrics. By introducing sodium benzenesulfonate into the modified polysiloxane chain segment, a large number of hydrophilic groups are formed on the composite polyester fiber, thereby improving the hygroscopic performance of the composite polyester fiber. In addition, when preparing the composite polyester fiber, polyvinyl alcohol is used as a pore-forming agent. The porosity of the composite polyester fiber is increased by elution, thereby providing a channel for moisture transfer and evaporation, enhancing moisture conduction, and further improving the moisture absorption and quick-drying performance of the polyester fiber fabric. The increase in porosity also reduces the smoothness of the fiber surface, making it more difficult for the fiber heads to entangle with each other to form pills. At the same time, the presence of pores inside the fiber can also make the fiber softer and more flexible when rubbed, thereby reducing the possibility of pilling and improving the anti-pilling performance of the polyester fiber fabric. DETAILED DESCRIPTION

[0068] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0069] In the present application, polyethylene glycol is polyethylene glycol 1000; nylon 6 is polyamide 6, brand is Taiwan Chishen, China, model is TP-4208, melting point is 220-230° C.; polyvinyl alcohol is PVA17-92.

[0070] Example 1

[0071] This embodiment provides a process for preparing polyester fiber fabric by regenerating polyester waste bottle flakes, comprising the following steps:

[0072] S1. Preparation of alcoholysis extract

[0073] Add the polyester waste bottle pieces into a pulverizer, pulverize them, and pass them through a 60-mesh screen to obtain polyester recycled powder;

[0074] Sodium hydroxide, sodium dodecyl sulfate, polyethylene glycol 800, anhydrous ethanol and purified water were mixed evenly in a dosage ratio of 12 g: 3 g: 2 g: 60 mL: 50 mL to obtain a pretreatment solution for later use;

[0075] The polyester regenerated powder and the pretreatment solution were added into a three-necked flask at a ratio of 1 g:7 mL and stirred. The temperature of the three-necked flask was raised to 65°C and stirred for 50 min. The temperature of the three-necked flask was lowered to room temperature and filtered. The filter cake was washed with a 40 vol% ethanol solution until it was neutral and then dried. The filter cake was transferred to a drying oven at a temperature of 70°C and vacuum dried to constant weight to obtain the pretreated polyester powder.

[0076] Weigh: 200 g of pretreated polyester powder, 700 mL of ethylene glycol and 2 g of zinc acetate are added to a three-necked flask protected by nitrogen and stirred. After the three-necked flask is sealed, the temperature is raised to 180°C and the reaction is kept warm for 6 hours. The temperature of the three-necked flask is lowered to room temperature, and 5000 mL of 3 wt% sodium dodecyl sulfate aqueous solution is added to the reaction system. Stir and disperse for 20 minutes, filter, wash the filter cake with purified water three times and then dry it. Transfer the filter cake to a drying oven at a temperature of 70°C and vacuum dry it to constant weight to obtain an alcoholysis extract.

[0077] S2. Preparation of copolyester

[0078] Weigh: 150g of alcoholysis extract, 40g of 1,4-butenediol and 0.2g of antimony trioxide are added to a three-necked flask protected by nitrogen and stirred. After the three-necked flask is sealed, the temperature is raised to 240°C, and the reaction is kept warm for 60min. 30g of polyethylene glycol and 40g of nylon 6 are added to the three-necked flask, and the mixture is kept warm and stirred for 20min. The three-necked flask is evacuated to a vacuum pressure of -0.1MPa in the reaction system, and the reaction is kept warm. The speed is set to 80r / min. When the stirring output power increases by 10%, nitrogen is introduced into the three-necked flask, the internal pressure of the three-necked flask is raised to normal pressure, and the material is discharged while hot to obtain copolyester.

[0079] S3. Preparation of modified polysiloxane

[0080] Weigh: 23.1 g of sodium p-aminobenzenesulfonate and 231 mL of tetrahydrofuran are added to a three-necked flask protected by nitrogen and stirred. The temperature of the three-necked flask is raised to 60° C. and stirred until the system is dissolved. 21.7 g of 3-isocyanatopropylmethyldiethoxysilane is added to the three-necked flask, and the reaction is kept warm for 40 minutes. The tetrahydrofuran is evaporated under reduced pressure to obtain modified sodium sulfonate;

[0081] Formic acid and purified water were mixed evenly at a ratio of 1 g:2 mL to obtain a formic acid solution;

[0082] Weigh: 30g of modified sodium sulfonate, 150g of octamethylcyclotetrasiloxane, 60g of cyclotetradimethylsiloxane and 800mL of xylene, add them into a three-necked flask and stir, add 100mL of formic acid solution into the three-necked flask, seal the three-necked flask and raise the temperature to 110°C, keep warm and react for 4h, add 18g of 1,1,3,3-tetramethyldisiloxane into the three-necked flask, keep warm and react for 2h, lower the temperature of the reaction system to room temperature, add 0.2mol / L sodium hydroxide solution into the reaction system, adjust the pH of the system to 7, stand and separate, wash the organic phase with purified water 3 times, dry it with anhydrous magnesium sulfate for 2h, transfer the organic phase to a rotary evaporator with a water bath temperature of 70°C, and evaporate xylene under reduced pressure to obtain modified polysiloxane.

[0083] S4. Preparation of composite polyester

[0084] Weigh: 700g of copolyester, 150g of modified polysiloxane, 40g of polyvinyl alcohol, 2g of chloroplatinic acid and 5L of N-methylpyrrolidone, add into a three-necked flask protected by nitrogen and stir, raise the temperature of the three-necked flask to 90°C, keep warm for 6h, lower the temperature of the three-necked flask to room temperature, slowly pour the reaction solution into a stirring kettle containing 30L of anhydrous ethanol while stirring, stir and disperse for 20min, filter, wash the filter cake with anhydrous ethanol 3 times and then dry it, transfer the filter cake to a drying oven at a temperature of 70°C, and vacuum dry it to a water content of 0.1% to obtain a composite polyester.

[0085] S5. Preparation of composite polyester fiber

[0086] The composite polyester is added into a twin-screw extruder, and the temperatures of the six temperature sections of the twin-screw extruder from the feed end to the discharge end are set to 260° C., 265° C., 265° C., 265° C., 270° C., and 270° C. in sequence, and the main shaft speed of the twin-screw extruder is 15 r / min. The composite polyester is melt-extruded into a spinning machine with a spinning temperature of 280° C., an air-cooled air supply temperature of 35° C., and a blowing rate of 0.6 m / s through the twin-screw extruder, and melt-spinning is performed to obtain spun fibers;

[0087] The spun fiber was stretched at a temperature of 80° C. and a stretching ratio of 1.5 to obtain a composite polyester fiber precursor;

[0088] The composite polyester fiber precursor and 5wt% sodium dodecyl sulfate solution were added into a beaker at a ratio of 1g:20mL and kept completely immersed. The temperature of the beaker was raised to 80°C and ultrasonically dispersed for 60 minutes. The polyester fiber precursor was taken out of the beaker, washed three times with purified water, and dried to obtain a composite polyester fiber.

[0089] S6. Preparation of polyester fiber fabric

[0090] The composite polyester fibers are blended to prepare composite polyester yarns with a linear density of 100D / 36F, and then the composite polyester yarns are plain woven to prepare polyester fiber fabrics, wherein the warp density is 140 yarns / inch and the weft density is 90 yarns / inch.

[0091] Example 2

[0092] This embodiment provides a process for preparing polyester fiber fabric by regenerating polyester waste bottle flakes, comprising the following steps:

[0093] S1. Preparation of alcoholysis extract

[0094] Add the polyester waste bottle pieces into a pulverizer, pulverize them, and pass them through a 60-mesh screen to obtain polyester recycled powder;

[0095] Mix sodium hydroxide, sodium dodecyl sulfate, polyethylene glycol 800, anhydrous ethanol and purified water in a ratio of 14 g:4 g:3 g:60 mL:50 mL to obtain a pretreatment solution for later use;

[0096] The polyester regenerated powder and the pretreatment solution were added into a three-necked flask at a ratio of 1 g: 8 mL and stirred. The temperature of the three-necked flask was raised to 70°C and stirred for 55 min. The temperature of the three-necked flask was lowered to room temperature and filtered. The filter cake was washed with a 40 vol% ethanol solution until it was neutral and then dried. The filter cake was transferred to a drying oven at a temperature of 75°C and vacuum dried to constant weight to obtain the pretreated polyester powder.

[0097] Weigh: 200 g of pretreated polyester powder, 800 mL of ethylene glycol and 2 g of zinc acetate are added to a three-necked flask protected by nitrogen and stirred. After the three-necked flask is sealed, the temperature is raised to 190°C and the reaction is kept warm for 7 hours. The temperature of the three-necked flask is lowered to room temperature, and 5000 mL of 3 wt% sodium dodecyl sulfate aqueous solution is added to the reaction system. Stir and disperse for 25 minutes, filter, wash the filter cake with purified water three times and then dry it. Transfer the filter cake to a drying oven at a temperature of 75°C and vacuum dry it to constant weight to obtain an alcoholysis extract.

[0098] S2. Preparation of copolyester

[0099] Weigh: 175g of alcoholysis extract, 50g of 1,4-butenediol and 0.25g of antimony trioxide are added to a three-necked flask protected by nitrogen and stirred. After the three-necked flask is sealed, the temperature is raised to 245°C, and the reaction is kept warm for 70 minutes. 35g of polyethylene glycol and 45g of nylon 6 are added to the three-necked flask, and the mixture is stirred for 25 minutes. The three-necked flask is evacuated to a vacuum pressure of -0.1MPa in the reaction system, and the reaction is kept warm. The speed is set to 90r / min. When the stirring output power increases by 15%, nitrogen is introduced into the three-necked flask, the internal pressure of the three-necked flask is raised to normal pressure, and the material is discharged while hot to obtain copolyester.

[0100] S3. Preparation of modified polysiloxane

[0101] Weigh: 23.1 g of sodium p-aminobenzenesulfonate and 289 mL of tetrahydrofuran are added to a three-necked flask protected by nitrogen and stirred. The temperature of the three-necked flask is raised to 63° C. and stirred until the system is dissolved. 21.7 g of 3-isocyanatopropylmethyldiethoxysilane is added to the three-necked flask, and the reaction is kept warm for 50 min. The tetrahydrofuran is evaporated under reduced pressure to obtain modified sodium sulfonate;

[0102] Formic acid and purified water were mixed evenly at a ratio of 1 g:2 mL to obtain a formic acid solution;

[0103] Weigh: 40g of modified sodium sulfonate, 165g of octamethylcyclotetrasiloxane, 65g of cyclotetradimethylsiloxane and 850mL of xylene, add them into a three-necked flask and stir, add 125mL of formic acid solution into the three-necked flask, seal the three-necked flask and raise the temperature to 115°C, keep warm and react for 4.5h, add 20g of 1,1,3,3-tetramethyldisiloxane into the three-necked flask, keep warm and react for 2.5h, lower the temperature of the reaction system to room temperature, add 0.25mol / L sodium hydroxide solution into the reaction system, adjust the pH of the system to 7, stand and separate, wash the organic phase with purified water 3 times, dry it with anhydrous magnesium sulfate for 2.5h, transfer the organic phase to a rotary evaporator with a water bath temperature of 75°C, and evaporate xylene under reduced pressure to obtain modified polysiloxane.

[0104] S4. Preparation of composite polyester

[0105] Weigh: 750g of copolyester, 160g of modified polysiloxane, 55g of polyvinyl alcohol, 2.5g of chloroplatinic acid and 5.5L of N-methylpyrrolidone, add into a three-necked flask protected by nitrogen and stir, raise the temperature of the three-necked flask to 95°C, keep warm for 7h, lower the temperature of the three-necked flask to room temperature, slowly pour the reaction solution into a stirring kettle containing 30L of anhydrous ethanol while stirring, stir and disperse for 25min, filter, wash the filter cake with anhydrous ethanol 3 times and then dry it, transfer the filter cake to a drying oven at a temperature of 75°C, and vacuum dry it to a water content of 0.07% to obtain a composite polyester.

[0106] S5. Preparation of composite polyester fiber

[0107] The composite polyester is added into a twin-screw extruder, and the temperatures of the six temperature sections of the twin-screw extruder from the feed end to the discharge end are set to 260° C., 265° C., 265° C., 265° C., 270° C., and 270° C. in sequence, and the main shaft speed of the twin-screw extruder is 17 r / min. The composite polyester is melt-extruded into a spinning machine with a spinning temperature of 285° C., an air-cooled air supply temperature of 40° C., and an air blowing rate of 0.7 m / s through the twin-screw extruder, and melt-spinning is performed to obtain spun fibers;

[0108] The spun fiber was stretched at a temperature of 85° C. and a stretching ratio of 1.7 to obtain a composite polyester fiber precursor;

[0109] The composite polyester fiber precursor and 5wt% sodium dodecyl sulfate solution were added into a beaker at a ratio of 1g:25mL, and the mixture was completely immersed. The temperature of the beaker was raised to 85°C, and ultrasonic dispersion was performed for 70 minutes. The polyester fiber precursor was taken out of the beaker, washed three times with purified water, and dried to obtain a composite polyester fiber.

[0110] S6. Preparation of polyester fiber fabric

[0111] The composite polyester fibers are blended to prepare composite polyester yarns with a linear density of 110D / 36F, and then the composite polyester yarns are plain woven to prepare polyester fiber fabrics, wherein the warp density is 180 yarns / inch and the weft density is 120 yarns / inch.

[0112] Example 3

[0113] This embodiment provides a process for preparing polyester fiber fabric by regenerating polyester waste bottle flakes, comprising the following steps:

[0114] S1. Preparation of alcoholysis extract

[0115] Add the polyester waste bottle pieces into a pulverizer, pulverize them, and pass them through a 60-mesh screen to obtain polyester recycled powder;

[0116] Sodium hydroxide, sodium dodecyl sulfate, polyethylene glycol 800, anhydrous ethanol and purified water were mixed evenly in a dosage ratio of 16 g: 5 g: 4 g: 60 mL: 50 mL to obtain a pretreatment solution for later use;

[0117] The polyester regenerated powder and the pretreatment solution were added into a three-necked flask at a ratio of 1 g:9 mL and stirred. The temperature of the three-necked flask was raised to 75°C and stirred for 60 min. The temperature of the three-necked flask was lowered to room temperature and filtered. The filter cake was washed with a 40 vol% ethanol solution until it was neutral and then dried. The filter cake was transferred to a drying oven at a temperature of 80°C and vacuum dried to constant weight to obtain the pretreated polyester powder.

[0118] Weigh: 200 g of pretreated polyester powder, 900 mL of ethylene glycol and 2 g of zinc acetate are added to a three-necked flask protected by nitrogen and stirred. After the three-necked flask is sealed, the temperature is raised to 200°C and the reaction is kept warm for 8 hours. The temperature of the three-necked flask is lowered to room temperature, and 5000 mL of 3 wt% sodium dodecyl sulfate aqueous solution is added to the reaction system. Stir and disperse for 30 minutes, filter, wash the filter cake with purified water three times and then dry it. Transfer the filter cake to a drying oven at a temperature of 80°C and vacuum dry it to constant weight to obtain an alcoholysis extract.

[0119] S2. Preparation of copolyester

[0120] Weigh: 180g of alcoholysis extract, 60g of 1,4-butenediol and 0.3g of antimony trioxide, add them into a three-necked flask protected by nitrogen and stir. After the three-necked flask is sealed, the temperature is raised to 250°C, and the reaction is kept warm for 80min. 40g of polyethylene glycol and 50g of nylon 6 are added to the three-necked flask, and the mixture is stirred for 30min. The three-necked flask is evacuated to a vacuum pressure of -0.1MPa in the reaction system, and the reaction is kept warm. The speed is set to 100r / min. When the stirring output power increases by 20%, nitrogen is introduced into the three-necked flask, the internal pressure of the three-necked flask is raised to normal pressure, and the material is discharged while hot to obtain copolyester.

[0121] S3. Preparation of modified polysiloxane

[0122] Weigh: 23.1 g of sodium p-aminobenzenesulfonate and 347 mL of tetrahydrofuran are added to a three-necked flask protected by nitrogen and stirred. The temperature of the three-necked flask is raised to 65° C. and stirred until the system is dissolved. 21.7 g of 3-isocyanatopropylmethyldiethoxysilane is added to the three-necked flask, and the reaction is kept warm for 60 min. The tetrahydrofuran is evaporated under reduced pressure to obtain modified sodium sulfonate;

[0123] Formic acid and purified water were mixed evenly at a ratio of 1 g:2 mL to obtain a formic acid solution;

[0124] Weigh: 50g of modified sodium sulfonate, 180g of octamethylcyclotetrasiloxane, 70g of cyclotetradimethylsiloxane and 900mL of xylene, add them into a three-necked flask and stir, add 150mL of formic acid solution into the three-necked flask, seal the three-necked flask and raise the temperature to 120°C, keep warm and react for 5h, add 22g of 1,1,3,3-tetramethyldisiloxane into the three-necked flask, keep warm and react for 3h, lower the temperature of the reaction system to room temperature, add 0.3mol / L sodium hydroxide solution into the reaction system, adjust the pH of the system to 7, stand and separate, wash the organic phase with purified water 3 times, dry it with anhydrous magnesium sulfate for 3h, transfer the organic phase to a rotary evaporator with a water bath temperature of 80°C, evaporate xylene under reduced pressure to obtain modified polysiloxane.

[0125] S4. Preparation of composite polyester

[0126] Weigh: 800g of copolyester, 170g of modified polysiloxane, 70g of polyvinyl alcohol, 3g of chloroplatinic acid and 6L of N-methylpyrrolidone, add into a three-necked flask protected by nitrogen and stir, raise the temperature of the three-necked flask to 100°C, keep warm for 8h, lower the temperature of the three-necked flask to room temperature, slowly pour the reaction solution into a stirring kettle containing 30L of anhydrous ethanol while stirring, stir and disperse for 30min, filter, wash the filter cake with anhydrous ethanol 3 times and then dry it, transfer the filter cake to a drying oven at a temperature of 80°C, and vacuum dry it to a water content of 0.05% to obtain a composite polyester.

[0127] S5. Preparation of composite polyester fiber

[0128] The composite polyester is added into a twin-screw extruder, and the temperatures of the six temperature sections of the twin-screw extruder from the feed end to the discharge end are set to 260° C., 265° C., 265° C., 265° C., 270° C., and 270° C. in sequence, and the main shaft speed of the twin-screw extruder is 18 r / min. The composite polyester is melt-extruded into a spinning machine with a spinning temperature of 290° C., an air-cooled air supply temperature of 45° C., and a blowing rate of 0.8 m / s through the twin-screw extruder, and melt-spinning is performed to obtain spun fibers;

[0129] The spun fiber was stretched at a temperature of 90° C. and a stretching ratio of 1.8 to obtain a composite polyester fiber precursor;

[0130] The composite polyester fiber precursor and 5wt% sodium dodecyl sulfate solution were added into a beaker at a ratio of 1g:30mL, and the mixture was completely immersed. The temperature of the beaker was raised to 90°C, and ultrasonic dispersion was performed for 80 minutes. The polyester fiber precursor was taken out of the beaker, washed three times with purified water, and dried to obtain a composite polyester fiber.

[0131] S6. Preparation of polyester fiber fabric

[0132] The composite polyester fibers are blended to prepare composite polyester yarns with a linear density of 120D / 36F, and then the composite polyester yarns are plain woven to prepare polyester fiber fabrics, wherein the warp density is 200 yarns / inch and the weft density is 150 yarns / inch.

[0133] Comparative Example 1

[0134] The difference between this comparative example and Example 3 is that in step S2, 1,4-butenediol is not added.

[0135] Comparative Example 2

[0136] The difference between this comparative example and Example 3 is that in step S3, when preparing the modified polysiloxane, no modified sodium sulfonate is added.

[0137] Comparative Example 3

[0138] The difference between this comparative example and Example 3 is that in step S4, no modified polysiloxane is added.

[0139] Comparative Example 4

[0140] The difference between this comparative example and Example 3 is that the composite polyester fiber in step S6 is replaced by the composite polyester fiber precursor in step S5.

[0141] Performance Test:

[0142] The water absorption rate, liquid water diffusion rate, maximum wetting radius and unidirectional transfer index of the polyester fiber fabric samples prepared in Examples 1-3 and Comparative Examples 1-4 were measured with reference to the standard GB / T 21655.2-2019 "Evaluation of Moisture Absorption and Quick-Drying of Textiles Part 2: Dynamic Moisture Transfer Method";

[0143] The polyester fiber fabric samples prepared in Examples 1-3 and Comparative Examples 1-4 were rubbed 50 times, 100 times and 500 times respectively with reference to the standard GB / T 21196.4-2007 "Determination of the abrasion resistance of textile fabrics by the Martindale method - Part 4: Evaluation of changes in appearance". Then, the pilling levels of the rubbed polyester fiber fabric samples were rated with reference to the standard GB / T 4802.2-2008 "Determination of the pilling properties of textile fabrics - Part 2: Modified Martindale method". The specific test results are shown in Table 1 below.

[0144] Table 1-Performance test data of the sample

[0145]

[0146] Data Analysis:

[0147] A comparative analysis of the data in Table 1 above shows that the water absorption rate of the polyester fiber fabric prepared by the present invention reaches 87.1% / s, the liquid water diffusion rate reaches 4.5 mm / s, the maximum wetting radius reaches 22.1 mm, and the one-way transfer index reaches 282.5. After 100 frictions, the pilling level of the sample reaches level 5, and after 500 frictions, the pilling level of the sample reaches level 4.5. All performance test data are better than those of the comparative example, indicating that the present invention uses nylon 6 and polyvinyl alcohol to enhance the alcoholysis extract of polyester bottle flakes, and then prepares a composite polyester with modified polysiloxane modified with benzenesulfonic acid, and then uses polyvinyl alcohol as a pore-forming agent to prepare a porous composite polyester fiber, which not only effectively improves the moisture absorption and quick-drying performance of the polyester fiber fabric, enhances the wearing experience of the polyester fiber fabric, but also improves the wear resistance and anti-pilling performance of the polyester fiber fabric.

[0148] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A process for preparing polyester fiber fabric by regenerating polyester waste bottle flakes, characterized in that: The following steps are involved: S1, adding the polyester waste bottle pieces into a pulverizer, pulverizing them, passing through a 60-mesh sieve, and obtaining polyester recycled powder; S2, pre-treating the polyester recycled powder to obtain pre-treated polyester powder, and then alcoholyzing the pre-treated polyester powder to obtain an alcoholysis extract; S3. Under nitrogen protection, the alcoholysis extract, 1,4-butenediol and the catalyst are mixed, the temperature of the reaction system is raised to 240-250°C after the reaction system is sealed, and the reaction is kept warm for 60-80 minutes, polyethylene glycol and nylon 6 are added to the reaction system, and the reaction is stirred for 20-30 minutes, and the reaction system is evacuated to a vacuum pressure of -0.1 MPa, and the reaction is kept warm. When the output power increases by 10-20% under constant stirring speed, post-treatment is performed to obtain copolyester; S4, reinforcing and modifying the copolyester with modified polysiloxane to prepare a composite polyester; S5, preparing composite polyester fibers by melt spinning, stretching and impregnation of the composite polyester, and then preparing polyester fiber fabrics using the polyester fibers as raw materials; The alcoholysis method in step S2 is: under nitrogen protection, pretreated polyester powder, ethylene glycol and catalyst zinc acetate are mixed, the reaction system is sealed and the temperature is raised to 180-200° C., the temperature is kept for 6-8 hours, and the alcoholysis extract is obtained by post-treatment; The modified polysiloxane is processed by the following steps: B1. Under nitrogen protection, sodium p-aminobenzenesulfonate and tetrahydrofuran are mixed, the temperature of the reaction system is raised to 60-65° C., stirred until the system is dissolved, 3-isocyanatopropylmethyldiethoxysilane is added to the reaction system, the reaction is kept warm for 40-60 minutes, and post-processed to obtain modified sodium sulfonate; B2. Mix modified sodium sulfonate, octamethylcyclotetrasiloxane, cyclotetradimethylsiloxane and xylene, add formic acid solution to the reaction system, seal the reaction system, increase the temperature of the reaction system to 110-120°C, keep the temperature for 4-5 hours, add 1,1,3,3-tetramethyldisiloxane to the reaction system, keep the temperature for 2-3 hours, and post-treat to obtain modified polysiloxane.

2. The process for preparing polyester fiber fabric by regenerating polyester waste bottle flakes according to claim 1, characterized in that: In step S2, the pretreatment step is: adding the polyester recycled powder into the pretreatment solution and stirring, raising the temperature of the pretreatment solution to 65-75°C, stirring for 50-60 minutes, and post-treating to obtain the pretreated polyester powder.

3. The process for preparing polyester fiber fabric by regenerating polyester waste bottle flakes according to claim 2, characterized in that: The polyester recycled powder and the pretreatment solution are used in a ratio of 1 g:7-9 mL. The pretreatment solution is composed of sodium hydroxide, sodium dodecyl sulfate, polyethylene glycol 800, anhydrous ethanol and purified water in a ratio of 12-16 g:3-5 g:2-4 g:60 mL:50 mL.

4. The process for preparing polyester fiber fabric by regenerating polyester waste bottle flakes according to claim 1, characterized in that: In step S3, the weight ratio of the alcoholysis extract, 1,4-butene glycol, catalyst, polyethylene glycol and nylon 6 is 150-180:40-60:0.2-0.3:30-40:40-50, the catalyst is antimony trioxide, and the post-treatment includes: after the reaction is completed, under nitrogen protection, the reaction system is restored to normal pressure, and the material is discharged to obtain copolyester.

5. The process for preparing polyester fiber fabric by regenerating polyester waste bottle flakes according to claim 1, characterized in that: In step S4, the preparation method of the composite polyester is: mixing the copolyester, modified polysiloxane, polyvinyl alcohol, a catalyst and N-methylpyrrolidone, raising the temperature of the reaction system to 90-100° C., keeping the reaction temperature for 6-8 hours, and post-treating to obtain the composite polyester.

6. The process for preparing polyester fiber fabric by regenerating polyester waste bottle flakes according to claim 5, characterized in that: The dosage ratio of the copolyester, modified polysiloxane, polyvinyl alcohol, catalyst and N-methylpyrrolidone is 70-80g:15-17g:4-7g:0.2-0.3g:500-600mL, and the catalyst is chloroplatinic acid.

7. The process for preparing polyester fiber fabric by regenerating polyester waste bottle flakes according to claim 1, characterized in that: In step B1, the amount ratio of the sodium p-aminobenzenesulfonate and 3-isocyanatopropylmethyldiethoxysilane is 1 mol:1 mol, and the amount ratio of the sodium p-aminobenzenesulfonate and tetrahydrofuran is 1 g:10-15 mL; in step B2, the amount ratio of the modified sodium sulfonate, octamethylcyclotetrasiloxane, cyclotetramethylsiloxane, xylene, formic acid solution and 1,1,3,3-tetramethyldisiloxane is 3-5 g:15-18 g:6-7 g:80-90 mL:10-15 mL:1.8-2.2 g, and the formic acid solution is composed of formic acid and purified water at 1 g:2 mL.

8. The process for preparing polyester fiber fabric by regenerating polyester waste bottle flakes according to claim 1, characterized in that: The composite polyester fiber is processed by the following steps: C1. Adding the composite polyester into a twin-screw extruder, extruding the composite polyester into a spinning machine through the twin-screw extruder, and stretching the composite polyester fiber precursor after melt spinning; C2, placing the composite polyester fiber precursor in an impregnation solution at a temperature of 80-90° C., ultrasonically dispersing for 60-80 minutes, and post-treating to obtain a composite polyester fiber; C3. Blending the composite polyester fibers to prepare composite polyester yarns, and then weaving the composite polyester yarns to prepare polyester fiber fabrics.

9. The process for preparing polyester fiber fabric by regenerating polyester waste bottle flakes according to claim 8, characterized in that: In step C1, the spinning temperature of the melt spinning machine is 280-290°C, air cooling curing is adopted during melt spinning, the air cooling air supply temperature is 35-45°C, the blowing rate is 0.6-0.8m / s, the stretching temperature is 80-90°C, and the stretching ratio is 1.5-1.8 times; in step C2, the dosage ratio of the composite polyester fiber precursor and the impregnation liquid is 1g:20-30mL, and the impregnation liquid is 5wt% sodium dodecyl sulfate solution; in step C3, the linear density of the composite polyester yarn is 100-120D / 36F.

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