Intelligent temperature-adjusting moisture-absorbing quick-drying fiber and preparation method thereof

Abstract

The invention discloses an intelligent temperature-adjusting moisture-absorbing quick-drying fiber and a preparation method thereof. The preparation method comprises the following steps: 1) preparing PNIPAM; (2) preparing scCO2 / DMSO (dimethyl sulfoxide); (3) preparing starch modified EVOH; (4) mixing NIPAM (N-isopropylacrylamide) and starch modified EVOH (ethylene-vinyl alcohol), introducing scCO2 / DMSO (dimethyl sulfoxide), carrying out grafting reaction to generate PNIPAM-g-EVOH, and drying for later use; (5) EVOH, PNIPAM, PNIPAM-g-EVOH and an antioxidant are weighed and added into a high-speed stirrer to be stirred and smashed, and a smashed mixture is obtained; (6) melting, extruding and granulating the crushed mixture to serve as a skin layer, and spinning by adopting a skin-core composite structure; and (7) the washable stability is improved. According to the invention, EVOH is used as a base material, the basic performance of the fiber is maintained, the fiber is endowed with temperature response performance, and the wearing comfort of moisture-absorbing and quick-drying textiles is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of textile materials, and in particular to an intelligent temperature-regulating, moisture-absorbing and quick-drying fiber and a preparation method thereof. Background Art

[0002] Quick-drying textiles are highly favored in the fields of sportswear, outdoor clothing, etc. due to their characteristics of rapid sweating and keeping dry. Their skin-friendly fabric layers usually adopt hydrophobic fibers or are subjected to hydrophobic finishing to enhance the ability of moisture to pass through quickly. When the hydrophobic fabric contacts the skin, it is easy to cause a sticky feeling and even skin discomfort. Although this design improves the quick-drying performance, when the environment fluctuates greatly, such fabrics often lead to a decrease in wearing comfort. In order to overcome the adverse effect that the skin-friendly fabric layer of traditional moisture-absorbing and quick-drying textiles must be hydrophobic and affect human comfort, it is urgent to develop a fiber with temperature-responsive hydrophilic-hydrophobic transition characteristics, which can simultaneously meet the skin-friendly requirements at low temperature without sweating and the quick-drying requirements at high temperature with a lot of sweating. Summary of the Invention

[0003] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide an intelligent temperature-regulating, moisture-absorbing and quick-drying fiber and a preparation method thereof, using EVOH as a substrate, endowing the fiber with temperature-responsive performance while maintaining the basic performance of the fiber, and greatly improving the wearing comfort of moisture-absorbing and quick-drying textiles.

[0004] An intelligent temperature-regulating, moisture-absorbing and quick-drying fiber provided by the present invention has the structure represented by formula (1);

[0005]

[0006] In addition, the present invention also provides a preparation method of the above intelligent temperature-regulating, moisture-absorbing and quick-drying fiber, comprising the following steps:

[0007] 1) Prepare PNIPAM, and reserve it after freeze-drying;

[0008] 2) Add a certain amount of DMSO solution, supercritical CO2 (scCO2) and co-solvent into the reaction kettle, heat up and pressurize to reach its critical point to make them compatible and blend to obtain scCO2 / DMSO, and store it for later use at the target temperature and pressure;

[0009] 3) Prepare starch-modified EVOH, and reserve it after cooling at room temperature;

[0010] 4) Mix NIPAM and starch-modified EVOH, and then introduce scCO2 / DMSO to carry out a grafting reaction to generate PNIPAM-g-EVOH, and dry it for later use;

[0011] 5) Weigh a certain amount of EVOH, PNIPAM, PNIPAM-g-EVOH and antioxidant, add them to a high-speed blender, stir and crush to obtain a crushed mixture;

[0012] 6) Melt-extrude and pelletize the crushed mixture to be used as the skin layer, and spin using a core-sheath composite structure to obtain intelligent temperature-regulating, moisture-absorbing and quick-drying fibers;

[0013] 7) Use a crosslinking agent to improve the wash fastness stability of the intelligent temperature-regulating, moisture-absorbing and quick-drying fibers.

[0014] Furthermore, in the said step 1), the preparation of PNIPAM includes the following steps:

[0015] 11) Add NIPAM and distilled water to the flask in a mass ratio of 1:10 - 1:20, magnetically stir the NIPAM suspension until it dissolves;

[0016] 12) Evacuate the NIPAM solution or purge it with nitrogen for 25 - 30 min to remove dissolved oxygen;

[0017] 13) Add the initiator KPS to the NIPAM solution, evacuate again or purge with nitrogen and seal the flask; wherein, the mass fraction of KPS is 0 - 3.2 wt%;

[0018] 14) Stir and react the mixed solution at 60 - 70 °C for 5 - 6 h to obtain PNIPAM, and freeze-dry it for standby.

[0019] Furthermore, in the said step 2), the preparation of scCO2 / DMSO includes the following steps:

[0020] 21) Mix DMSO and the co-solvent in a volume ratio of 5:1 - 10:1;

[0021] 22) Inject the mixed DMSO / co-solvent into the reaction kettle to 60 - 70% of its volume, seal it and heat it up to 40 - 60 °C, and pre-pressurize it to 8 - 12 MPa;

[0022] 23) Increase the pressure at a rate of 0.4 - 0.5 MPa / min to 15 - 25 MPa, start magnetic stirring, the rotation speed ≥ 600 rpm, and maintain it for 25 - 30 min;

[0023] 24) When the system is a single-phase transparent state, keep the pressure fluctuation < ±0.2 MPa, continuously introduce scCO2 for 1.5 - 2 h, the flow rate is 1.5 - 2 L / min, and when the change in the characteristic peak intensity of DMSO detected by NIR ≤ 5% is stable, obtain scCO2 / DMSO.

[0024] Furthermore, before preparing the starch-modified EVOH in the said step 3), first modify the starch, including the following steps:

[0025] 311) Mix starch and distilled water at a volume ratio of 1:4 - 1:5, and then adjust the pH to 8.5 - 9.5;

[0026] 312) Add 5% alkenyl succinic anhydride and stir and react at 30 - 40 °C for 4 - 6 h;

[0027] 313) Neutralize the pH to 6.5 - 7.0, centrifuge and wash, and dry to obtain hydrophobic starch ester.

[0028] Furthermore, in step 3), the starch - modified EVOH is prepared by mixing using the chemical cross - linking modification method, including the following steps:

[0029] 321) Immerse EVOH and hydrophobic starch ester in the cross - linker solution and adjust the pH to 10 - 11;

[0030] 322) React at 60 - 80 °C for 1 - 2 h to form a cross - linked network;

[0031] 323) Wash and dry the obtained product to obtain cross - linked composite starch - modified EVOH.

[0032] Furthermore, in step 4), the grafting reaction includes the following steps:

[0033] 41) React the hydroxyl groups of starch - modified EVOH with an amination reagent through a copper catalyst to form aminated starch - modified EVOH, and at the same time add a radical initiator for activation; among them, control the radical grafting temperature at 60 - 80 °C, and the copper - catalyzed amination environment is pH 7 - 8;

[0034] 42) Centrifuge to extract the reaction precipitate, wash it with hot water at 60 °C and then dry it to obtain PNIPAM - g - EVOH.

[0035] Furthermore, in step 5), the mass fraction of EVOH is 0 wt.% - 75 wt.%, the mass fraction of PNIPAM is 0 wt.% - 20 wt.%, and the mass fraction of PNIPAM - g - EVOH is 0 wt.% - 30 wt.%.

[0036] Furthermore, in step 6), use a micro twin - screw extruder to melt - extrude and granulate the crushed mixture; use a drawing machine to draw to obtain intelligent temperature - adjustable, moisture - absorbing and quick - drying fibers;

[0037] The core layer in the skin - core composite structure includes but is not limited to polyolefin - based thermoplastic elastomers, thermoplastic polyurethanes, polyamides, polyvinyl chlorides, ethylene - vinyl alcohol copolymers or combinations thereof.

[0038] Further, in step 7), the intelligent temperature-regulating moisture-absorbing and quick-drying fiber is placed in a crosslinking agent at 40-45 °C and reacted for 1-2 h, and then washed and dried; the crosslinking agent includes glutaraldehyde with a mass fraction of 1.5-2.5 wt.% and ethanol with a mass fraction of 2.5-3.0 wt.%.

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0040] (1) The present invention uses starch-modified EVOH and in-situ generates PNIPAM-g-EVOH by scCO2 / DMSO, reducing the risk of phase separation, and having a core-shell structure with the inner layer as the core material and the outer layer as the composite material; the cortical material makes the fiber surface have wear resistance, strength or rigidity, and the core material provides softness, elasticity or fluffiness, having both high strength and certain toughness. The characteristics of presenting different properties at different temperatures can intelligently adjust the state of the fabric according to the changes in the external environment, greatly improving the wearing comfort.

[0041] (2) At the same time, ethylene-vinyl alcohol copolymer (EVOH) and temperature-responsive polymer PNIPAM are melt-blended and spun to prepare temperature-responsive fibers. Since both hydrophilic amide groups and hydrophobic isopropyl functional groups exist in the PNIPAM molecule, when the temperature is less than the LCST, water molecules are easy to form hydrogen bonds with the amide groups of the polymer to enhance its water absorption performance. When the temperature is greater than the LCST, the hydrogen bond interaction between the amide group and water molecules weakens, and the hydrophobic interaction of the hydrophobic isopropyl groups increases, and the hydrophilicity of the polymer weakens. At the same time, through the crosslinking of glutaraldehyde, some hydroxyl groups on the fiber surface are converted into acetal structures, reducing the hydrophilicity of the fiber and further increasing the water drying rate. The crosslinked fibers exhibit good moisture-absorbing and quick-drying properties.

[0042] (3) Through experimental verification, the fiber material prepared in this application not only has good moisture-absorbing and quick-drying properties, but also exhibits good mechanical properties, dyeability and use stability. At the same time, the preparation process is simple, and there is no solution discharge during melt-blending composite spinning, resulting in less pollution.

[0043] It should be understood that the content described in the summary of the invention is not intended to limit the key or important features of the embodiments of the present invention, nor to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, objects and advantages of the present invention will become more obvious:

[0045] Figure 1 It is a flowchart for the preparation of intelligent temperature-regulating moisture-absorbing and quick-drying fibers;

[0046] Figure 2 Schematic diagram of the TG curve of the sample for the thermal stability and compatibility test;

[0047] Figure 3 Schematic diagram of the DTG curve of the sample for the thermal stability and compatibility test;

[0048] Figure 4 Schematic diagram of the influence of the antioxidant on the breaking strength of the sample in the tensile mechanical property analysis test;

[0049] Figure 5 Schematic diagram of the contact angle of the sample at different temperatures in the moisture absorption and quick-drying temperature response performance test;

[0050] Figure 6 Schematic diagram of the maximum moisture absorption of the sample in the moisture absorption and quick-drying temperature response performance test;

[0051] Figure 7 Moisture release curve of the sample in the moisture absorption and quick-drying temperature response performance test;

[0052] Figure 8 Schematic diagram of the semi-drying time of the sample in the moisture absorption and quick-drying temperature response performance test. Detailed implementation mode

[0053] The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related invention, rather than limiting the invention. In addition, it should be noted that for the convenience of description, only the parts related to the invention are shown in the drawings.

[0054] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and embodiments.

[0055] Please refer to Figures 1 to 6 , the embodiment of the present invention provides an intelligent temperature-regulating moisture-absorbing and quick-drying fiber, having the structure represented by formula (1);

[0056]

[0057] In addition, the embodiment of the present invention also provides a preparation method of the intelligent temperature-regulating moisture-absorbing and quick-drying fiber as described above, including the following steps:

[0058] 1) Prepare PNIPAM;

[0059] 11) Add NIPAM and distilled water to the flask in a mass ratio of 1:10 - 1:20, and magnetically stir the NIPAM suspension until it dissolves;

[0060] 12) The NIPAM solution is evacuated or purged with nitrogen for 25 - 30 min to remove dissolved oxygen;

[0061] 13) The initiator KPS is added to the NIPAM solution, and then evacuated or purged with nitrogen again and the flask is sealed; among them, the mass fraction of KPS is 0 - 3.2 wt%;

[0062] 14) The mixed solution is stirred and reacted at 60 - 70 °C for 5 - 6 h to obtain PNIPAM, which is freeze - dried for standby;

[0063] 2) A certain amount of DMSO solution, supercritical CO2 (scCO2) and cosolvent are added to the reaction kettle, heated and pressurized to reach its critical point to make them compatible and blend to obtain scCO2 / DMSO, and stored for standby under the target temperature and pressure;

[0064] The preparation of scCO2 / DMSO includes the following steps:

[0065] 21) DMSO and the cosolvent are mixed at a volume ratio of 5:1 - 10:1;

[0066] 22) The mixed DMSO / cosolvent is injected into the reaction kettle to 60 - 70% of its volume, sealed and heated to 40 - 60 °C, and pre - pressurized to 8 - 12 MPa;

[0067] 23) The pressure is increased at a rate of 0.4 - 0.5 MPa / min to 15 - 25 MPa, the magnetic stirring is started, the rotation speed is ≥600 rpm, and it is maintained for 25 - 30 min;

[0068] 24) When the system is a single - phase transparent, keep the pressure fluctuation <±0.2 MPa, continuously introduce scCO2 for 1.5 - 2 h, the flow rate is 1.5 - 2 L / min, and when the change in the characteristic peak intensity of DMSO detected by NIR is ≤5%, it is stable, and scCO2 / DMSO is obtained;

[0069] 3) Prepare starch - modified EVOH, and cool it at room temperature for standby;

[0070] 311) Starch and distilled water are mixed at a volume ratio of 1:4 - 1:5, and then the pH is adjusted to 8.5 - 9.5;

[0071] 312) Add 5% alkenyl succinic anhydride and stir - react at 30 - 40 °C for 4 - 6 h;

[0072] 313) Neutralize the pH to 6.5 - 7.0, centrifuge, wash, and dry to obtain hydrophobic starch ester;

[0073] 321) Immerse EVOH and the hydrophobic starch ester in the cross - linker solution and adjust the pH to 10 - 11;

[0074] 322) React at 60 - 80 °C for 1 - 2 h to form a crosslinked network;

[0075] 323) Wash and dry the obtained product to obtain crosslinked composite starch - modified EVOH;

[0076] 4) Mix NIPAM and starch - modified EVOH, and then introduce scCO2 / DMSO to carry out a grafting reaction to generate PNIPAM - g - EVOH, which is dried for standby;

[0077] The grafting reaction includes the following steps:

[0078] 41) React the hydroxyl groups of starch - modified EVOH with an amination reagent through a copper catalyst to form aminated starch - modified EVOH, and at the same time add a radical initiator for activation; among them, control the radical grafting temperature at 60 - 80 °C, and the copper - catalyzed amination environment is pH 7 - 8;

[0079] 42) Centrifuge to extract the reaction precipitate, wash it with hot water at 60 °C and then dry it to obtain PNIPAM - g - EVOH;

[0080] 5) Weigh EVOH with a mass fraction of 0 wt.% - 75 wt.%, PNIPAM with a mass fraction of 0 wt.% - 20 wt.%, PNIPAM - g - EVOH with a mass fraction of 0 wt.% - 30 wt.% and an antioxidant, add them to a high - speed mixer, stir and crush to obtain a crushed mixture;

[0081] 6) Use a micro - twin - screw extruder to melt - extrude and granulate the crushed mixture as the skin layer, and use a skin - core composite structure for spinning. The core layer includes but is not limited to polyolefin - based thermoplastic elastomers, thermoplastic polyurethanes, polyamides, polyvinyl chlorides, ethylene - vinyl alcohol copolymers or combinations thereof; use a draw frame to draw to obtain intelligent temperature - regulating, moisture - absorbing and quick - drying fibers;

[0082] 7) Place the intelligent temperature - regulating, moisture - absorbing and quick - drying fibers in a crosslinking agent at 40 - 45 °C and react for 1 - 2 h, then wash and dry to improve the wash - fastness stability of the intelligent temperature - regulating, moisture - absorbing and quick - drying fibers; the crosslinking agent includes glutaraldehyde with a mass fraction of 1.5 - 2.5 wt.% and ethanol with a mass fraction of 2.5 - 3.0 wt.%.

[0083] In this embodiment, starch-modified EVOH and scCO2 / DMSO are used to in-situ generate PNIPAM-g-EVOH, reducing the risk of phase separation. It has a core-shell structure with the inner layer as the core material and the outer layer as the composite material. The cortical material endows the fiber surface with wear resistance, strength or rigidity, while the core material provides softness, elasticity or fluffiness. It has both high strength and certain toughness. The property of presenting different performances at different temperatures can intelligently adjust the state of the fabric according to the changes in the external environment, greatly improving the wearing comfort.

[0084] Meanwhile, ethylene-vinyl alcohol copolymer (EVOH) and temperature-responsive polymer PNIPAM are melt-blended and spun to prepare temperature-responsive fibers. Since there are both hydrophilic amide groups and hydrophobic isopropyl functional groups in the PNIPAM molecule, when the temperature is lower than the LCST, water molecules are prone to form hydrogen bonds with the amide groups of the polymer, enhancing its water absorption performance. When the temperature is higher than the LCST, the hydrogen bond interaction between the amide group and water molecules weakens, and the hydrophobic interaction of the hydrophobic isopropyl groups strengthens, resulting in a decrease in the hydrophilicity of the polymer. At the same time, through the cross-linking of glutaraldehyde, some hydroxyl groups on the fiber surface are converted into acetal structures, reducing the hydrophilicity of the fiber and further enhancing the moisture drying rate. The cross-linked fibers exhibit good moisture absorption and quick-drying properties.

[0085] Verified by experiments, the fiber material prepared in this application not only has good moisture absorption and quick-drying properties, but also exhibits good mechanical properties, dyeability and use stability. At the same time, the preparation process is simple. Using melt-blending composite spinning, there is no solution discharge and less pollution.

[0086] Example 1

[0087] Weigh 5 g of N-isopropylacrylamide (NIPAM) into a round-bottom flask, add 75 ml of distilled water and stir magnetically until dissolved. Evacuate the dissolved solution for 30 min to remove the dissolved oxygen in the water. Then add 3.2 wt.% of initiator potassium persulfate (KPS), evacuate again and seal the flask. Stir and react the sealed flask at 70 °C for 6 h. After the reaction is completed, centrifuge to extract the precipitate, rinse it with hot water at 60 °C and dry it to obtain poly-N-isopropylacrylamide (PNIPAM).

[0088] Weigh 20 ml of dimethyl sulfoxide (DMSO) into a reaction kettle, add 2 mL of absolute ethanol (cosolvent), evacuate for 30 min to remove the dissolved oxygen in the water, seal it and heat it to 50 °C, pre-pressurize to 10 MPa, and then increase the pressure at a rate of 0.5 MPa / min to 20 MPa after stabilization and stir magnetically until the solution system becomes a single-phase transparent. Continuously introduce scCO2 at a flow rate of 2 L / min for 2 h, and detect the DMSO characteristic peak (1650 cm -1)The strength change ≤ 5% is considered stable, and it is stored for standby at 60°C.

[0089] Prepare 30 mL of starch solution with a starch solid-liquid ratio of 1:5, adjust the pH to 8.5 - 9.5, add 5% vinyl succinic anhydride (ASA), stir and react at 40°C for 6 h, neutralize the solution pH to 6.5 - 7.0, centrifuge and wash, and dry to obtain hydrophobic starch ester. Immerse 5 g of ethylene-vinyl alcohol copolymer (EVOH) and hydrophobic starch ester into the crosslinking agent solution, and adjust the pH to 10 - 11. React the reactants at 80°C for 2 h to form a crosslinked network, and the product is washed and dried for standby. Weigh a certain amount of NIPAM, initiator, catalyst, amination reagent, and starch-modified EVOH into the reaction kettle, and introduce scCO2 / DMSO, activate with a radical initiator, and at the same time react the copper catalyst with the amination reagent, control the pH value at 8 and stir and react at 70°C for 3 h. After the reaction is completed, centrifuge to extract the precipitate, rinse with hot water at 60°C and dry to obtain PNIPAM-g-EVOH.

[0090] Weigh a certain amount of PNIPAM-g-EVOH, EVOH, PNIPAM, and antioxidant and add them to a high-speed mixer to stir and pulverize. The mass ratio of PNIPAM-g-EVOH, EVOH, and PNIPAM is 3:9:1, and the mass fraction of antioxidant 1076 is 0.3 wt.%. Then, melt and extrude and pelletize with a micro twin-screw extruder. The working temperatures of the preheating zone, melting zone, pressurizing zone, and die head heating zone of the micro twin-screw extruder are 160°C, 175°C, 190°C, and 195°C respectively. Melt and extrude the masterbatch with a twin-screw extruder as the skin layer, use a skin-core composite structure spinning with EVOH as the core layer, and draw 2.2 times with a drawing machine to obtain a series of EVOH / PNIPAM temperature-responsive fibers.

[0091] Prepare a mixed solution of 2.5 wt.% glutaraldehyde and 3 wt.% acetic acid as the crosslinking agent. Place the sample in the crosslinking agent at 45°C and react for 2 h, wash and dry, and label it as F-10.

[0092] Experimental Example 2 - Example 5

[0093] The difference from Example 1 is that:

[0094] (1) In step 3): The contents of each component of EVOH, PNIPAM, and antioxidant are different;

[0095] (2) In Examples 2 - 4, they did not react with the crosslinking agent.

[0096] The contents of each component of Examples 1 - 5 are listed in Table 1.

[0097] Table 1 Sample numbers and their component contents

[0098]

[0099] I. Thermal Stability and Shrinkage Rate Test:

[0100] To explore the thermal stability of the polymer, the thermal decomposition temperature and rate of the polymer were tested. As Figure 2 shown, from the TG curve of F-P, it can be seen that the carbon chain of F-P starts to break and gradually carbonize when the temperature reaches 351.3 °C. This temperature is close to the decomposition temperature of EVOH, but much higher than the spinning temperature (195 °C).

[0101] As Figure 3 shown, when the temperature reaches 395.4 °C, the thermal decomposition rate of F-0 reaches the maximum; while the temperature at which the thermal decomposition rate of F-P reaches the maximum is 383.8 °C. The two are relatively close and exhibit relatively similar thermal stability.

[0102] II. Tensile Mechanical Property Analysis Test:

[0103] As Figure 4 shown, the addition of antioxidants significantly improves the strength of the fibers. Especially when the content of PNIPAM in the fibers increases, the strength improvement effect brought by the antioxidants is more obvious. Therefore, the addition of antioxidants can effectively reduce the strength loss problem of the fibers during processing.

[0104] III. Moisture Absorption, Quick Drying and Temperature Responsive Property Test:

[0105] Contact Angle Test:

[0106] As Figure 5 shown, as the blending ratio of PNIPAM increases, the contact angle of the fibers under normal temperature conditions gradually decreases. This is because below the LCST, the amide groups of the PNIPAM polymer have high hydrophilic properties and can form hydrogen bonds with water molecules, causing more water to adhere to the fiber surface and thus improving its wetting property. As the blending ratio increases, the number of amide groups on the fiber surface increases, the hydrophilicity gradually enhances, and the contact angle gradually decreases. When the temperature is higher than the LCST, the contact angle increases and the hydrophilic property of the fiber decreases.

[0107] Moisture Absorption Rate Test:

[0108] As Figure 6 shown, after 24 hours of moisture absorption, the moisture absorption rate of sample F-0 is 5.86%, while the maximum moisture absorption rate of the sample after PNIPAM blending modification is 7.68%, which is 1.3 times that of the unmodified sample F-0. The relatively high moisture absorption rate can provide a more comfortable wearing experience for the fabric and improve its service performance. As the blending ratio increases, more hydrophilic PNIPAM is distributed on the fiber surface, and the moisture absorption rate also gradually increases.

[0109] Drying performance test:

[0110] PNIPAM exhibits hydrophobicity at high temperatures, which is helpful for improving the drying performance of fibers. As Figure 7 shown, after adding PNIPAM, the moisture release rate of the fibers during drying is significantly higher than that of F-0 without PNIPAM. As Figure 8 shown, as the blending ratio increases, the semi-drying time of the fibers gradually decreases, indicating good quick-drying performance.

[0111] In the description of this specification, the descriptions of terms such as "one embodiment" and "some embodiments" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or instance. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0112] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various modifications and changes can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. An intelligent temperature-regulating, moisture-absorbing and quick-drying fiber, characterized in that: Having a structure represented by formula (1); 2. A method for preparing the intelligent temperature-regulating, moisture-absorbing and quick-drying fiber according to claim 1, characterized in that: The steps include: 1) Prepare PNIPAM and freeze-dry it for later use; 2) adding a certain amount of DMSO solution, supercritical CO2 (scCO2) and co-solvent into a reactor, raising the temperature and pressurizing to their critical point to make them compatible and blended to obtain scCO2 / DMSO, and storing them at the target temperature and pressure for future use; 3) preparing starch-modified EVOH, cooling it at room temperature and setting it aside; 4) Mix NIPAM and starch-modified EVOH, then introduce scCO2 / DMSO to cause grafting reaction to generate PNIPAM-g-EVOH, which is then dried for later use; 5) Weighing a certain amount of EVOH, PNIPAM, PNIPAM-g-EVOH and antioxidant, adding them into a high-speed mixer, stirring and crushing to obtain a crushed mixture; 6) The crushed mixture is melt-extruded and granulated to form a skin layer, and a skin-core composite structure is used for spinning to obtain an intelligent temperature-regulating, moisture-absorbing and quick-drying fiber; 7) A cross-linking agent is used to improve the washing stability of the intelligent temperature-regulating moisture-absorbing and quick-drying fiber.

3. The preparation method according to claim 2, characterized in that: In the step 1), the preparation of PNIPAM comprises the following steps: 11) Add NIPAM and distilled water in a mass ratio of 1:10-1:20 into a flask and mix, and magnetically stir the NIPAM suspension until it dissolves; 12) Vacuum or pass nitrogen through the NIPAM solution for 25-30 minutes to remove dissolved oxygen; 13) Add initiator KPS to the NIPAM solution, evacuate or ventilate with nitrogen again and seal the flask; wherein the mass fraction of KPS is 0-3.2wt%, 14) The mixed solution was stirred at 60-70° C. for 5-6 h to obtain PNIPAM, which was freeze-dried for later use.

4. The preparation method according to claim 2, characterized in that: In the step 2), preparing scCO2 / DMSO comprises the following steps: 21) mixing DMSO and a cosolvent in a volume ratio of 5:1-10:1; 22) Inject the mixed DMSO / co-solvent into the reaction kettle to 60-70% of the volume, seal it, heat it to 40-60°C, and pre-pressurize it to 8-12MPa; 23) Increase the pressure to 15-25 MPa at a rate of 0.4-0.5 MPa / min, start magnetic stirring, the speed is ≥ 600 rpm, and maintain for 25-30 min; 24) When the system is single-phase and transparent, the pressure fluctuation is maintained at <±0.2MPa, scCO2 is continuously introduced for 1.5-2h, the flow rate is 1.5-2L / min, and the NIR detection DMSO characteristic peak intensity change is ≤5%, which means it is stable, and scCO2 / DMSO is obtained.

5. The preparation method according to claim 2, characterized in that: In the step 3), before preparing starch-modified EVOH, the starch is first modified, comprising the following steps: 311) starch and distilled water are mixed in a volume ratio of 1:4-1:5, and the pH is adjusted to 8.5-9.5; 312) Add 5% alkenyl succinic anhydride and stir the reaction at 30-40°C for 4-6h; 313) neutralizing the mixture to a pH of 6.5-7.0, washing by centrifugation, and drying to obtain a hydrophobic starch ester.

6. The preparation method according to claim 5, characterized in that: In the step 3), starch-modified EVOH is prepared by mixing using a chemical cross-linking modification method, comprising the following steps: 321) immersing EVOH and hydrophobic starch ester in a crosslinking agent solution, and adjusting the pH to 10-11; 322) react at 60-80°C for 1-2h to form a cross-linked network; 323) The obtained product is washed and dried to obtain a cross-linked composite material starch-modified EVOH.

7. The preparation method according to claim 2, characterized in that: In step 4), the grafting reaction comprises the following steps: 41) reacting the hydroxyl groups of starch-modified EVOH with an amination agent through a copper catalyst to form amino-modified starch-modified EVOH, and adding a free radical initiator for activation; wherein the free radical grafting temperature is controlled at 60-80° C., and the copper-catalyzed amination environment is pH 7-8; 42) The reaction precipitate was extracted by centrifugation, rinsed with hot water at 60°C and then dried to obtain PNIPAM-g-EVOH.

8. The preparation method according to claim 2, characterized in that: In the step 5), the mass fraction of EVOH is 0wt.%-75wt.%, the mass fraction of PNIPAM is 0wt.%-20wt.%, and the mass fraction of PNIPAM-g-EVOH is 0wt.%-30wt.%.

9. The preparation method according to claim 2, characterized in that: In the step 6), a micro twin-screw extruder is used to melt and extrude the crushed mixture into granules; a drawing machine is used to draw to obtain intelligent temperature-regulating, moisture-absorbing and quick-drying fibers; The core layer in the skin-core composite structure includes, but is not limited to, polyolefin thermoplastic elastomer, thermoplastic polyurethane, polyamide, polyvinyl chloride, ethylene-vinyl alcohol copolymer or a combination thereof.

10. The preparation method according to claim 2, characterized in that: In the step 7), the intelligent temperature-regulating, moisture-absorbing and quick-drying fiber is placed in a cross-linking agent at 40-45° C. for reaction for 1-2 hours and then washed and dried; the cross-linking agent includes 1.5-2.5wt.% glutaraldehyde and 2.5-3.0wt.% ethanol.

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