High-moisture-permeability polyester fiber and preparation method thereof

Abstract

The invention relates to the technical field of high-performance polyester fibers, particularly belongs to the patent classification number D01F6 / 00, and discloses a high-moisture-permeability polyester fiber and a preparation method thereof. Comprising the following steps: carrying out hydrothermal reaction on magnesium nitrate hexahydrate and aluminum nitrate nonahydrate to prepare layered double hydroxide nanosheets; then, sodium alginate is prepared into a solution, and the solution is cross-linked with calcium chloride to obtain alginic acid aerogel powder; then, carrying out ultrasonic oscillation dispersion on the two substances in deionized water, and cooling and drying to obtain composite aerogel; then, the composite aerogel and polyethylene glycol 4000 are subjected to melt blending and granulation in a double-screw extruder, and functional master batches are obtained; and finally, mixing the functional master batch with polyethylene glycol terephthalate slices, performing melt spinning at a specific spinning temperature and speed, and performing cooling forming and drafting to obtain the high-moisture-permeability polyester fiber. According to the method, through material compounding and process control, the moisture permeability of the polyester fiber is effectively improved, and the method has a good application prospect in the textile field.

Description

Technical Field

[0001] The present invention relates to the technical field of high-performance polyester fibers, specifically belonging to the patent classification number D01F6 / 00, and specifically relates to a highly moisture-permeable polyester fiber and a preparation method thereof. Background Art

[0002] In the field of textile materials, polyester fibers are widely used in multiple fields such as clothing, home textiles, and industrial textiles due to their excellent strength, abrasion resistance, wrinkle resistance, and good dimensional stability. They are one of the synthetic fibers with the largest usage volume globally. However, traditional polyester fibers have the problem of poor moisture permeability, which severely limits their application in some scenarios with high requirements for wearing comfort and functionality.

[0003] During normal physiological activities, the human body continuously produces sweat. Fabrics with poor moisture permeability cannot timely discharge the sweat to the outside world, resulting in the accumulation of sweat between the skin and the fabric. This not only makes the wearer feel sticky and uncomfortable but also affects the normal breathing of the skin, reduces the body's heat regulation ability, and may even cause skin diseases in the long term, greatly affecting the wearing experience. In the fields of sportswear, outdoor clothing, and medical textiles, good moisture permeability is a key indicator to ensure product performance and user comfort. For example, athletes sweat a lot during high-intensity training or competitions. If the clothing has insufficient moisture permeability and the sweat cannot evaporate quickly, it will increase the body burden and affect sports performance; if medical textiles have poor moisture permeability, it is not conducive to wound healing and may also breed bacteria.

[0004] To solve the problem of poor moisture permeability of polyester fibers, the prior art mostly adopts the method of modifying polyester fibers. However, the current modification methods have many limitations. For example, the chemical grafting method uses chemical reactions to introduce hydrophilic groups onto the polyester molecular chain, but its reaction conditions are harsh, the requirements for equipment are high, and the original structure and properties of polyester fibers may be damaged during the reaction, affecting other performance indicators such as the strength of the fibers. Therefore, it is urgent to develop a new highly moisture-permeable polyester fiber and break through the limitations of the existing technology. Summary of the Invention

[0005] The purpose of the present invention is to provide a highly moisture-permeable polyester fiber and a preparation method thereof to solve the technical problem of poor moisture permeability of polyester fibers proposed in the above background art.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A preparation method of a highly moisture-permeable polyester fiber, comprising the following steps:

[0008] S1. Add magnesium nitrate hexahydrate and aluminum nitrate nonahydrate into deionized water, heat and stir to dissolve, then dropwise add sodium hydroxide solution to adjust the pH to alkaline, and then transfer it to a high-pressure reactor for hydrothermal reaction. After centrifugal separation, washing and drying, layered double hydroxide nanosheets are obtained;

[0009] S2. Add sodium alginate into deionized water, stir to dissolve to prepare a sodium alginate solution, add calcium chloride solution under stirring conditions for cross-linking reaction to obtain a gel-like substance, soak it in deionized water to remove unreacted ions, and then perform freeze-drying and grinding to obtain sodium alginate aerogel powder;

[0010] S3. Add the layered double hydroxide nanosheets and sodium alginate aerogel powder into deionized water, perform ultrasonic oscillation dispersion, and then perform cooling and drying to obtain a composite aerogel;

[0011] S4. Add the composite aerogel and polyethylene glycol 4000 into a twin-screw extruder, control the temperature at 230 - 235 °C and the screw speed at 300 - 350 r / min for melt blending, and then granulate to obtain a functional masterbatch;

[0012] S5. Mix the functional masterbatch and polyethylene terephthalate chips evenly, add the mixed material into a melt spinning machine, control the spinning temperature at 280 - 300 °C and the spinning speed at 4200 - 5000 m / min for melt spinning, and after cooling and shaping and drawing, high moisture permeability polyester fibers are obtained.

[0013] In the technical solution of the present invention, first, magnesium nitrate hexahydrate and aluminum nitrate nonahydrate are used to react to obtain layered double hydroxide nanosheets, which have a unique layered structure that can allow water molecules to diffuse between layers in the form of a single molecular layer, forming a molecular-level sieving effect. And the carbonate ions between layers can form hydrogen bonds with water molecules, further promoting the directional diffusion of water molecules, greatly increasing the diffusion coefficient of water molecules between its layers. The sodium alginate aerogel formed after the cross-linking reaction of sodium alginate and calcium chloride has a rich microporous structure and a large specific surface area. These micropores can quickly absorb sweat, and a large number of carboxyl groups on its surface can form hydrogen bonds with water, and the water absorption capacity is as high as 2200% of its own mass, playing an efficient water collection role in the whole moisture permeability process. Combining the layered double hydroxide nanosheets with the sodium alginate aerogel forms a hierarchical pore network for the absorption and conduction of sweat, thereby greatly improving the moisture permeability of polyester fibers.

[0014] Polyethylene glycol not only acts as a plasticizer to reduce the melt viscosity of the composite system and improve the processing fluidity, but the ether bonds on its molecular chain also have a certain moisture absorption capacity. Acting synergistically with the hierarchical pores, it further enhances the moisture permeability of the fibers. Moreover, the flexible chain segments of polyethylene glycol can compensate for the loss of fiber rigidity caused by the addition of layered double hydroxides and alginate aerogels, enabling the fibers to maintain a relatively high breaking strength while possessing high moisture permeability. Additionally, in terms of the processing technology, the parameter settings of the twin-screw extruder are extremely crucial. Adding the composite aerogel and polyethylene glycol 4000 to the twin-screw extruder and controlling the temperature at 230 - 235 °C can ensure the full melting of polyethylene glycol 4000 while avoiding the decomposition of the layered double hydroxide nanosheets due to overheating. Controlling the screw speed at 300 - 350 r / min can provide an appropriate shear force to evenly disperse the composite aerogel in polyethylene glycol, laying a good foundation for the subsequent spinning process.

[0015] Preferably, in the step S1, the molar ratio of magnesium nitrate hexahydrate to aluminum nitrate nonahydrate is 3:1 - 2.

[0016] Preferably, in the step S1, the hydrothermal reaction temperature is 180 - 190 °C and the hydrothermal reaction time is 18 - 24 h.

[0017] Preferably, in the step S2, the cross-linking reaction time is 30 - 50 min.

[0018] Preferably, in the step S3, the mass ratio of the layered double hydroxide nanosheets to the alginate aerogel powder is 1:1 - 5.

[0019] Preferably, in the step S4, the mass ratio of the composite aerogel to polyethylene glycol 4000 is 1:2 - 3.

[0020] Preferably, in the step S5, the draw ratio is 4 - 4.5 times.

[0021] Preferably, in the step S3, the layered double hydroxide nanosheets are pre-modified, including the following steps:

[0022] Adding an epoxy group silane coupling agent to a mixed solution of ethanol and water, heating and stirring for hydrolysis to obtain an epoxy group silane coupling agent solution. Adding the layered double hydroxide nanosheets to the epoxy group silane coupling agent solution, heating and stirring for reaction, followed by centrifugal separation, washing, and drying to obtain epoxy-functionalized layered double hydroxide nanosheets;

[0023] Adding polyethyleneimine to deionized water, stirring to dissolve to obtain a polyethyleneimine solution. Adding the epoxy-functionalized layered double hydroxide nanosheets to the polyethyleneimine solution, heating to 80 - 85 °C, holding for reaction, followed by centrifugal separation, washing, and drying to obtain the product.

[0024] In the technical solution of the present invention, as described above, the composite aerogel and polyethylene glycol are added to a screw extruder for melt blending. During the melt blending process, the temperature is controlled at 230 - 235 °C and the screw speed is 300 - 350 r / min. The research team of the present invention has found through in-depth research that under the above parameter conditions (temperature control and screw speed), the composite aerogel is prone to disintegration, that is, the layered double hydroxide nanosheets and the alginate aerogel are prone to separation, damaging the absorption and conduction hierarchical pore network structure formed by the two, resulting in a significant decrease in the moisture permeability of the fiber. To further solve the above technical problems, the present invention modifies the layered double hydroxide nanosheets. Polyethyleneimine is grafted onto the surface of the layered double hydroxide nanosheets through an epoxy silane coupling agent. Since polyethyleneimine has a hyperbranched structure and carries a large number of amino groups, the surface of the nanosheets after loading the amino groups is positively charged, while the surface of the alginate aerogel is negatively charged. An electrostatic attraction will be generated between the two, promoting the approach and combination of the nanosheets and the alginate aerogel, and further making the combination between the layered double hydroxide nanosheets and the alginate aerogel more firm, and the interfacial bonding force is significantly enhanced. By grafting polyethyleneimine onto the surface of the layered double hydroxide nanosheets, the technical problem of the separation of the layered double hydroxide nanosheets and the alginate aerogel under the above operating parameters is well solved. In addition, since polyethyleneimine has a hyperbranched structure, after it is grafted onto the surface of the layered double hydroxide nanosheets, a dendritic divergent structure is formed. The surface of the double hydroxide nanosheets can bind more alginate aerogel, forming a more developed hierarchical pore network structure, thereby further improving the moisture permeability of the polyester fiber.

[0025] Preferably, the heat preservation reaction time is 5 - 10 h.

[0026] A highly moisture-permeable polyester fiber is prepared by the above method.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] 1. Utilize the molecular sieve effect of layered double hydroxide nanosheets and the high-efficiency water collection function of alginate aerogel to construct a hierarchical pore network, greatly improving the moisture permeability of polyester fibers. The hygroscopic ether bond of polyethylene glycol and the hierarchical pores cooperate to further enhance the moisture permeability effect, significantly increasing the moisture permeability rate of the fiber;

[0029] 2. Polyethylene glycol, as a plasticizer, reduces the melt viscosity of the composite system, improves the processing fluidity, and its flexible chain segments compensate for the loss of fiber rigidity caused by the addition of other materials, maintaining a relatively high breaking strength;

[0030] 3. The parameter settings of the twin-screw extruder ensure the uniform dispersion of the composite aerogel, laying a good foundation for the subsequent spinning process. The binding force between the layered double hydroxide nanosheets and the alginate aerogel is strong, and the two are not easily separated under the above parameter conditions, thus maintaining the high moisture permeability of the polyester fiber. Detailed implementation mode

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] Example 1

[0033] A preparation method of high moisture-permeable polyester fiber, comprising the following steps:

[0034] S1. Add 0.3 mol of magnesium nitrate hexahydrate and 0.15 mol of aluminum nitrate nonahydrate to 600 mL of deionized water, heat and stir to dissolve, then slowly add 1 mol / L sodium hydroxide solution to adjust the pH to 10, continue to stir for 1.5 h, and then transfer to a high-pressure reaction kettle for hydrothermal reaction. The hydrothermal reaction temperature is 185 °C, and the hydrothermal reaction time is 22 h. After centrifugal separation, washing and drying, layered double hydroxide nanosheets are obtained;

[0035] S2. Add 2 g of sodium alginate to 150 mL of deionized water, stir to dissolve, prepare a sodium alginate solution, add 80 mL of calcium chloride solution with a mass fraction of 1 wt% under stirring conditions, carry out a cross-linking reaction for 45 min to obtain a gel-like substance, soak in deionized water to remove unreacted ions, and then carry out freeze-drying, and after grinding, obtain alginate aerogel powder;

[0036] S3. Add 2 g of modified layered double hydroxide nanosheets and 8 g of alginate aerogel powder to 150 mL of deionized water, carry out ultrasonic oscillation dispersion at a power of 200 W for 50 min, and then carry out cooling and drying to obtain a composite aerogel;

[0037] S4. Add the composite aerogel and polyethylene glycol 4000 to a twin-screw extruder. The mass ratio of the composite aerogel to polyethylene glycol 4000 is 1:2.8. Control the temperature at 233 °C and the screw speed at 350 r / min, carry out melt blending for 10 min, and then granulate to obtain a functional masterbatch;

[0038] S5. Mix the functional masterbatch and polyethylene terephthalate chips evenly at a mass ratio of 1:35. Add the mixed material into a melt spinning machine, control the spinning temperature at 290 °C and the spinning speed at 4500 m / min, and carry out melt spinning. After cooling and forming and drawing, the drawing ratio is 4.2 times to obtain high moisture permeability polyester fibers.

[0039] Preparation of modified layered double hydroxide nanosheets:

[0040] Add 2 g of epoxy group silane coupling agent KH-560 into a mixed solution of 100 mL of ethanol and 8 mL of water, heat to 45 °C, stir and hydrolyze for 30 min to obtain an epoxy group silane coupling agent solution. Add 5 g of layered double hydroxide nanosheets into the epoxy group silane coupling agent solution, heat to 50 °C, stir and react for 2 h, and after centrifugal separation, washing and drying, obtain epoxy group layered double hydroxide nanosheets;

[0041] Add 0.5 g of polyethyleneimine into 100 mL of deionized water, stir and dissolve to obtain a polyethyleneimine solution. Add 2 g of epoxy group layered double hydroxide nanosheets into the polyethyleneimine solution, heat to 83 °C, keep warm and react for 8 h, and after centrifugal separation, washing and drying, it is obtained.

[0042] Example 2

[0043] A preparation method of high moisture permeability polyester fibers, comprising the following steps:

[0044] S1. Add 0.3 mol of magnesium nitrate hexahydrate and 0.15 mol of aluminum nitrate nonahydrate into 600 mL of deionized water, heat and stir to dissolve, then slowly dropwise add 1 mol / L sodium hydroxide solution to adjust the pH to 10, continue stirring for 1.5 h, and then transfer to a high-pressure reaction kettle for hydrothermal reaction. The hydrothermal reaction temperature is 185 °C and the hydrothermal reaction time is 19 h. After centrifugal separation, washing and drying, obtain layered double hydroxide nanosheets;

[0045] S2. Add 2 g of sodium alginate into 150 mL of deionized water, stir and dissolve to prepare a sodium alginate solution. Under stirring conditions, add 80 mL of calcium chloride solution with a mass fraction of 1 wt%, carry out cross-linking reaction for 35 min to obtain a gel-like substance, soak in deionized water to remove unreacted ions, and then carry out freeze-drying, and after grinding, obtain sodium alginate aerogel powder;

[0046] S3. Add 2 g of modified layered double hydroxide nanosheets and 3 g of sodium alginate aerogel powder into 150 mL of deionized water, carry out ultrasonic oscillation dispersion at a power of 200 W for 50 min, and then carry out cooling and drying to obtain a composite aerogel;

[0047] S4. Add the composite aerogel and polyethylene glycol 4000 into a twin-screw extruder. The mass ratio of the composite aerogel to polyethylene glycol 4000 is 1:2.3. Control the temperature at 233 °C, the screw speed at 300 r / min, carry out melt blending for 10 min, and then granulate to obtain the functional masterbatch.

[0048] S5. Mix the functional masterbatch and polyethylene terephthalate chips evenly according to a mass ratio of 1:35. Add the mixed material into a melt spinning machine. Control the spinning temperature at 290 °C and the spinning speed at 4500 m / min to carry out melt spinning. After cooling and shaping and drawing, the drawing ratio is 4.3 times to obtain the high moisture permeability polyester fiber.

[0049] Preparation of modified layered double hydroxide nanosheets:

[0050] Add 2 g of epoxy group silane coupling agent KH-560 into a mixed solution of 100 mL of ethanol and 8 mL of water, heat to 45 °C, stir and hydrolyze for 30 min to obtain an epoxy group silane coupling agent solution. Add 5 g of layered double hydroxide nanosheets into the epoxy group silane coupling agent solution, heat to 50 °C, stir and react for 2 h, and after centrifugal separation, washing and drying, obtain epoxy group layered double hydroxide nanosheets.

[0051] Add 0.5 g of polyethyleneimine into 100 mL of deionized water, stir and dissolve to obtain a polyethyleneimine solution. Add 2 g of epoxy group layered double hydroxide nanosheets into the polyethyleneimine solution, heat to 83 °C, keep warm and react for 7 h, and after centrifugal separation, washing and drying, it is obtained.

[0052] Example 3

[0053] A preparation method of high moisture permeability polyester fiber, comprising the following steps:

[0054] S1. Add 0.3 mol of magnesium nitrate hexahydrate and 0.15 mol of aluminum nitrate nonahydrate into 600 mL of deionized water, heat and stir to dissolve, then slowly dropwise add 1 mol / L sodium hydroxide solution to adjust the pH to 10, continue to stir for 1.5 h, and then transfer to a high-pressure reactor for hydrothermal reaction. The hydrothermal reaction temperature is 185 °C and the hydrothermal reaction time is 20 h. After centrifugal separation, washing and drying, obtain layered double hydroxide nanosheets.

[0055] S2. Add 2 g of sodium alginate into 150 mL of deionized water, stir and dissolve to prepare a sodium alginate solution. Under stirring conditions, add 80 mL of a calcium chloride solution with a mass fraction of 1 wt%, carry out a cross-linking reaction for 40 min to obtain a gel-like substance, soak in deionized water to remove unreacted ions, and then carry out freeze-drying and grinding to obtain sodium alginate aerogel powder.

[0056] S3. Add 2 g of modified layered double hydroxide nanosheets and 6 g of alginate aerogel powder into 150 mL of deionized water, perform ultrasonic oscillation dispersion at a power of 200 W for 50 min, and then cool and dry to obtain a composite aerogel.

[0057] S4. Add the composite aerogel and polyethylene glycol 4000 into a twin-screw extruder. The mass ratio of the composite aerogel to polyethylene glycol 4000 is 1:2.5. Control the temperature at 233 °C and the screw speed at 350 r / min, perform melt blending for 10 min, and then granulate to obtain a functional masterbatch.

[0058] S5. Mix the functional masterbatch and polyethylene terephthalate chips evenly according to a mass ratio of 1:35. Add the mixed material into a melt spinning machine. Control the spinning temperature at 290 °C and the spinning speed at 4500 m / min, perform melt spinning, and after cooling and forming and drawing, with a draw ratio of 4.3 times, obtain high moisture-permeable polyester fibers.

[0059] Preparation of modified layered double hydroxide nanosheets:

[0060] Add 2 g of epoxy group silane coupling agent KH-560 into a mixed solution of 100 mL of ethanol and 8 mL of water, heat to 45 °C, stir and hydrolyze for 30 min to obtain an epoxy group silane coupling agent solution. Add 5 g of layered double hydroxide nanosheets into the epoxy group silane coupling agent solution, heat to 50 °C, stir and react for 2 h, and after centrifugal separation, washing and drying, obtain epoxy group layered double hydroxide nanosheets.

[0061] Add 0.5 g of polyethyleneimine into 100 mL of deionized water, stir to dissolve to obtain a polyethyleneimine solution. Add 2 g of epoxy group layered double hydroxide nanosheets into the polyethyleneimine solution, heat to 83 °C, keep warm and react for 8 h, and after centrifugal separation, washing and drying, it is obtained.

[0062] Example 4

[0063] A preparation method of high moisture-permeable polyester fibers, comprising the following steps:

[0064] S1. Add 0.3 mol of magnesium nitrate hexahydrate and 0.2 mol of aluminum nitrate nonahydrate into 600 mL of deionized water, heat and stir to dissolve, then slowly dropwise add 1 mol / L sodium hydroxide solution to adjust the pH to 10, continue to stir for 1.5 h, and then transfer to a high-pressure reactor for hydrothermal reaction. The hydrothermal reaction temperature is 190 °C and the hydrothermal reaction time is 24 h. After centrifugal separation, washing and drying, obtain layered double hydroxide nanosheets.

[0065] S2. Add 2 g of sodium alginate to 150 mL of deionized water, stir to dissolve to prepare a sodium alginate solution. Under stirring conditions, add 80 mL of calcium chloride solution with a mass fraction of 1 wt%, carry out a cross-linking reaction for 50 min to obtain a gel-like substance, soak it in deionized water to remove unreacted ions, and then carry out freeze-drying. After grinding, sodium alginate aerogel powder is obtained;

[0066] S3. Add 2 g of modified layered double hydroxide nanosheets and 10 g of sodium alginate aerogel powder to 150 mL of deionized water, carry out ultrasonic oscillation dispersion at a power of 200 W for 50 min, and then carry out cooling and drying to obtain a composite aerogel;

[0067] S4. Add the composite aerogel and polyethylene glycol 4000 to a twin-screw extruder. The mass ratio of the composite aerogel to polyethylene glycol 4000 is 1:3. Control the temperature at 235 °C and the screw speed at 350 r / min, carry out melt blending for 10 min, and then carry out pelletizing to obtain a functional masterbatch;

[0068] S5. Mix the functional masterbatch and polyethylene terephthalate chips evenly according to a mass ratio of 1:35. Add the mixed material to a melt spinning machine. Control the spinning temperature at 300 °C and the spinning speed at 5000 m / min, carry out melt spinning, and through cooling forming and drawing, with a draw ratio of 4.5 times, high moisture-permeable polyester fibers are obtained.

[0069] Preparation of modified layered double hydroxide nanosheets:

[0070] Add 2 g of epoxy group silane coupling agent KH-560 to a mixed solution of 100 mL of ethanol and 8 mL of water, heat to 45 °C, stir and hydrolyze for 30 min to obtain an epoxy group silane coupling agent solution. Add 5 g of layered double hydroxide nanosheets to the epoxy group silane coupling agent solution, heat to 50 °C, stir and react for 2 h, and through centrifugal separation, washing and drying, epoxy group layered double hydroxide nanosheets are obtained;

[0071] Add 0.5 g of polyethyleneimine to 100 mL of deionized water, stir to dissolve to obtain a polyethyleneimine solution. Add 2 g of epoxy group layered double hydroxide nanosheets to the polyethyleneimine solution, heat to 85 °C, keep warm and react for 10 h, and through centrifugal separation, washing and drying, it is obtained.

[0072] Example 5

[0073] A method for preparing high moisture-permeable polyester fibers, comprising the following steps:

[0074] S1. Add 0.3 mol of magnesium nitrate hexahydrate and 0.1 mol of aluminum nitrate nonahydrate into 600 mL of deionized water, heat and stir to dissolve. Then slowly add 1 mol / L sodium hydroxide solution to adjust the pH to 10, continue stirring for 1.5 h, and then transfer to a high-pressure reactor for hydrothermal reaction. The hydrothermal reaction temperature is 180 °C and the hydrothermal reaction time is 18 h. After centrifugal separation, washing and drying, layered double hydroxide nanosheets are obtained.

[0075] S2. Add 2 g of sodium alginate into 150 mL of deionized water, stir to dissolve to prepare a sodium alginate solution. Under stirring conditions, add 80 mL of calcium chloride solution with a mass fraction of 1 wt%, carry out cross-linking reaction for 30 min to obtain a gel-like substance, soak in deionized water to remove unreacted ions, and then carry out freeze-drying and grinding to obtain sodium alginate aerogel powder.

[0076] S3. Add 2 g of modified layered double hydroxide nanosheets and 2 g of sodium alginate aerogel powder into 150 mL of deionized water, carry out ultrasonic oscillation dispersion at a power of 200 W for 50 min, and then carry out cooling and drying to obtain a composite aerogel.

[0077] S4. Add the composite aerogel and polyethylene glycol 4000 into a twin-screw extruder. The mass ratio of the composite aerogel to polyethylene glycol 4000 is 1:2. Control the temperature at 230 °C and the screw speed at 300 r / min, carry out melt blending for 10 min, and then granulate to obtain a functional masterbatch.

[0078] S5. Mix the functional masterbatch and polyethylene terephthalate chips evenly according to a mass ratio of 1:35. Add the mixed material into a melt spinning machine, control the spinning temperature at 280 °C and the spinning speed at 4200 m / min, carry out melt spinning, and through cooling forming and drawing, with a drawing ratio of 4 times, high moisture permeability polyester fibers are obtained.

[0079] Preparation of modified layered double hydroxide nanosheets:

[0080] Add 2 g of epoxy group silane coupling agent KH-560 into a mixed solution of 100 mL of ethanol and 8 mL of water, heat to 45 °C, stir and hydrolyze for 30 min to obtain an epoxy group silane coupling agent solution. Add 5 g of layered double hydroxide nanosheets into the epoxy group silane coupling agent solution, heat to 50 °C, stir and react for 2 h. After centrifugal separation, washing and drying, epoxy-based layered double hydroxide nanosheets are obtained.

[0081] Add 0.5 g of polyethyleneimine to 100 mL of deionized water, stir to dissolve to obtain a polyethyleneimine solution. Add 2 g of epoxy-based layered double hydroxide nanosheets to the polyethyleneimine solution, heat to 80 °C, and keep the reaction for 5 h. After centrifugal separation, washing, and drying, it is obtained.

[0082] Comparative Example 1

[0083] In Comparative Example 1, ordinary polyester fiber was used as a control.

[0084] Comparative Example 2

[0085] The difference between Comparative Example 2 and Example 1 is that:

[0086] Layered double hydroxide nanosheets are not added during the preparation process of polyester fiber;

[0087] The remaining operation steps are the same as those in Example 1.

[0088] Comparative Example 3

[0089] The difference between Comparative Example 3 and Example 1 is that:

[0090] Alginate aerogel powder is not added during the preparation process of polyester fiber;

[0091] The remaining operation steps are the same as those in Example 1.

[0092] Comparative Example 4

[0093] The difference between Comparative Example 4 and Example 1 is that:

[0094] During the preparation process of polyester fiber, in step S3,

[0095] Replace the modified layered double hydroxide nanosheets with layered double hydroxide nanosheets;

[0096] The remaining operation steps are the same as those in Example 1.

[0097] Comparative Example 5

[0098] The difference between Comparative Example 5 and Example 1 is that:

[0099] Omit step S4, blend the composite aerogel with polyester chips and melt-spin;

[0100] The remaining operation steps are the same as those in Example 1.

[0101] Performance test:

[0102] 1. Moisture permeability rate test:

[0103] Using the cup method (refer to GB / T12704.1-2009), the polyester fibers are woven into fabrics. The fiber fabric is sealed at the mouth of the moisture permeation cup, and desiccant is filled inside the cup. The moisture permeation rate is calculated by weighing the mass change within 24 hours. The specific steps are as follows: After the specimen is balanced under standard temperature and humidity (20±2°C, 65±2%RH), it is sealed at the cup mouth (exposed area 50cm 2 ), and placed in the test chamber. The calculation formula is:

[0104] Moisture permeation rate (g / m 2 ·24h) = (m1 - m2)×24 / A×t;

[0105] In the formula, m1 and m2 are the initial and ending masses, A is the exposed area (m 2 ), and t is the time (h). At least 5 parallel samples are tested in each group, and the results are averaged.

[0106] 2. Tensile strength test:

[0107] Using an electronic universal testing machine (refer to GB / T 14337-2008), cut a fiber bundle (length = 25cm), and stretch it to break at a speed of 200mm / min under a pre-tension of 0.5cN / dtex. Record the maximum breaking force (F), and calculate the tensile strength:

[0108] Tensile strength (cN / dtex) = F / d;

[0109] In the formula, d is the fiber linear density. 10 single filaments are tested in each group, and the results are averaged. The test environment needs to be controlled at 20±2°C, 65±2%RH.

[0110] The elongation at break is tested synchronously with the tensile strength, and the elongation rate is calculated by recording the elongation amount (ΔL) at break:

[0111] Elongation at break (%) = ΔL / L0×100%; In the formula, L0 is the initial gauge length.

[0112]

[0113] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing high moisture permeability polyester fiber, characterized in that, It includes the following steps: S1. Add magnesium nitrate hexahydrate and aluminum nitrate nonahydrate into deionized water, heat and stir to dissolve, then dropwise add sodium hydroxide solution to adjust the pH to be alkaline, and then transfer it to a high-pressure reactor for hydrothermal reaction. After centrifugal separation, washing and drying, layered double hydroxide nanosheets are obtained; S2. Add sodium alginate into deionized water, stir to dissolve, and prepare a sodium alginate solution. Under stirring conditions, add calcium chloride solution for cross-linking reaction to obtain a gel-like substance, soak it in deionized water to remove unreacted ions, and then perform freeze-drying and grinding to obtain sodium alginate aerogel powder; S3. Add the layered double hydroxide nanosheets and sodium alginate aerogel powder into deionized water, perform ultrasonic oscillation dispersion, and then perform cooling and drying to obtain a composite aerogel; S4. Add the composite aerogel and polyethylene glycol 4000 into a twin-screw extruder, control the temperature at 230 - 235 °C and the screw speed at 300 - 350 r / min for melt blending, and then granulate to obtain a functional masterbatch; S5. Mix the functional masterbatch and polyethylene terephthalate chips evenly, add the mixed material into a melt spinning machine, control the spinning temperature at 280 - 300 °C and the spinning speed at 4200 - 5000 m / min for melt spinning, and after cooling and shaping and drawing, high moisture permeability polyester fibers are obtained.

2. The preparation method of a highly moisture-permeable polyester fiber according to claim 1, characterized in that, In the step S1, the molar ratio of magnesium nitrate hexahydrate to aluminum nitrate nonahydrate is 3:1 - 2.

3. The preparation method of a highly moisture-permeable polyester fiber according to claim 1, characterized in that, In the step S1, the hydrothermal reaction temperature is 180 - 190 °C and the hydrothermal reaction time is 18 - 24 h.

4. The preparation method of a highly moisture-permeable polyester fiber according to claim 1, characterized in that In the step S2, the cross-linking reaction time is 30 - 50 min.

5. The preparation method of a highly moisture-permeable polyester fiber according to claim 1, characterized in that, In the step S3, the mass ratio of the layered double hydroxide nanosheets to the sodium alginate aerogel powder is 1:1 - 5.

6. The preparation method of a highly moisture-permeable polyester fiber according to claim 1, characterized in that, In the step S4, the mass ratio of the composite aerogel to polyethylene glycol 4000 is 1:2 - 3.

7. The preparation method of a high moisture permeability polyester fiber according to claim 1, characterized in that In the step S5, the draw ratio is 4 - 4.5 times.

8. The preparation method of a highly moisture-permeable polyester fiber according to claim 1, characterized in that, In the step S3, the layered double hydroxide nanosheets are subjected to pre-modification treatment, including the following steps: Add an epoxy group silane coupling agent into a mixed solution of ethanol and water, heat and stir for hydrolysis to obtain an epoxy group silane coupling agent solution. Add the layered double hydroxide nanosheets into the epoxy group silane coupling agent solution, heat and stir for reaction, and after centrifugal separation, washing and drying, epoxy group layered double hydroxide nanosheets are obtained; Add polyethyleneimine into deionized water, stir to dissolve to obtain a polyethyleneimine solution. Add the epoxy group layered double hydroxide nanosheets into the polyethyleneimine solution, heat to 80 - 85 °C for heat preservation reaction, and after centrifugal separation, washing and drying, it is obtained.

9. The preparation method of a highly moisture-permeable polyester fiber according to claim 8, characterized in that, The heat preservation reaction time is 5 - 10 h.

10. A highly moisture-permeable polyester fiber, characterized in that, Prepared by the method according to any one of claims 1 - 9.

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