Near-infrared shieldable spandex fiber, and preparation method and application thereof

Abstract

This invention relates to the field of fiber processing technology and discloses a near-infrared shielding elastic fiber and its preparation method. The method includes: (1) drying and melt spinning a styrene-ethylene-butene-styrene block copolymer to obtain an elastic fiber; and mixing MXene, dopamine hydrochloride and a dispersant in the presence of a solvent to obtain an impregnation solution; (2) impregnating the elastic fiber in the impregnation solution to obtain the near-infrared shielding elastic fiber. The near-infrared shielding elastic fiber prepared by the method provided by this invention has excellent near-infrared shielding effect and mechanical properties, and the preparation method provided by this invention is simple and has good economic value and application prospects.

Description

Technical Field

[0001] This invention relates to the field of fiber processing technology, specifically to an elastic fiber capable of near-infrared shielding, its preparation method, and its applications. Background Technology

[0002] Infrared stealth technology reduces a target's detectability by lowering or altering its infrared radiation characteristics. This primarily involves changing the target's infrared radiation properties, reducing its intensity, and adjusting the propagation path of the infrared radiation. Specific measures include improving thermal structure design, forced cooling of key heat-generating components, coating surfaces with infrared stealth materials, and using infrared camouflage and shielding. The goal of infrared stealth is to reduce or alter a target's infrared radiation characteristics, decreasing the effective range of infrared detection systems and thus lowering the probability of detection.

[0003] Infrared stealth materials mainly include low infrared emissivity stealth materials and cooling camouflage coatings. Examples include: 1) Metal coatings, which involve electrochemically oxidizing various metals or alloys, such as aluminum, copper, and iron, to form a thin, dense oxide film that reflects radiation; 2) Ceramic coatings, which use inorganic non-metallic materials as a coating layer to cover the entire surface with a uniform and robust ceramic layer, thus reflecting rays; and 3) Fiber weaving, which utilizes natural or synthetic high-molecular-weight organic compounds, specially processed and interwoven with fibers to create fabrics with different structures.

[0004] However, while the first two methods mentioned above have excellent infrared stealth capabilities, they are generally used for infrared stealth of large devices due to the high density of the materials, and are not suitable for small items such as clothing. The latter method, which uses natural or synthetic high-molecular organic compounds for special processing, is often more complex and has a poorer near-infrared shielding effect.

[0005] CN109869646A discloses a method for preparing electromagnetic shielding fabric based on two-dimensional layered MXene nanosheets. The method includes the following steps: (1) Pre-treating the fabric with an aqueous solution of sodium hydroxide and sodium carbonate to remove oil stains and impurities from the fabric surface, then washing with distilled water and drying; (2) Weighing a certain amount of Ti3AlC2 in the MAX phase, immersing it in a 10%-50% hydrofluoric acid aqueous solution, stirring for 18-24 hours, then filtering and washing with distilled water, and drying to obtain MXene powder; (3) Dissolving the MXene powder in a certain amount of water and ultrasonically obtaining a certain concentration of MXene solution; (4) First, spraying the MXene solution onto one side of the pre-treated fabric and drying it, then spraying the MXene solution onto the other side of the fabric and drying it. The MXene solution spraying process is uniform, resulting in MXene-modified fabric. This method uses a spraying method, which is not suitable for large-scale preparation. Furthermore, spraying can only modify the surface, and cannot achieve good modification of fibers with complex internal network structures. When the surface is worn or damaged, it loses its near-infrared shielding capability. Summary of the Invention

[0006] The purpose of this invention is to solve the problem that existing elastic fibers cannot simultaneously achieve both mechanical properties and near-infrared shielding effects.

[0007] To achieve the above objectives, a first aspect of the present invention provides a method for preparing near-infrared shielding elastic fibers, the method comprising:

[0008] (1) The styrene-ethylene-butene-styrene block copolymer was successively dried and melt-spun to obtain elastic fibers; and

[0009] In the presence of a solvent, MXene, dopamine hydrochloride and a dispersant are mixed to obtain an impregnation solution;

[0010] (2) The elastic fiber is impregnated in an impregnation solution to obtain the near-infrared shielding elastic fiber;

[0011] The solvent is a mixed solution of water and dimethylformamide with a volume ratio of 1:1-1.5;

[0012] The amount of MXene used is 0.16-0.45 g relative to 100 mL of solvent, the amount of dispersant used is 0.3-0.75 g, and the amount of dopamine hydrochloride used is 0.008-0.012 mol.

[0013] The dispersant is selected from at least one of sodium hexametaphosphate, sodium tripolyphosphate, and sodium humate.

[0014] A second aspect of the present invention provides an elastic fiber capable of near-infrared shielding prepared by the method described in the first aspect.

[0015] A third aspect of the present invention provides the application of the near-infrared shielding elastic fiber described in the second aspect in the textile field.

[0016] This invention uses styrene-ethylene-butene-styrene block copolymer as raw material to prepare elastic fibers, and impregnates them with a specific impregnation solution. The resulting near-infrared shielding elastic fibers have excellent near-infrared shielding effect and mechanical properties. Moreover, the preparation method provided by this invention is simple and has good economic value and application prospects. Detailed Implementation

[0017] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0018] As previously described, a first aspect of the present invention provides a method for preparing near-infrared shielding elastic fibers, the method comprising:

[0019] (1) The styrene-ethylene-butene-styrene block copolymer was successively dried and melt-spun to obtain elastic fibers; and

[0020] In the presence of a solvent, MXene, dopamine hydrochloride and a dispersant are mixed to obtain an impregnation solution;

[0021] (2) The elastic fiber is impregnated in an impregnation solution to obtain the near-infrared shielding elastic fiber;

[0022] The solvent is a mixed solution of water and dimethylformamide with a volume ratio of 1:1-1.5;

[0023] The amount of MXene used is 0.16-0.45 g relative to 100 mL of solvent, the amount of dispersant used is 0.3-0.75 g, and the amount of dopamine hydrochloride used is 0.008-0.012 mol.

[0024] The dispersant is selected from at least one of sodium hexametaphosphate, sodium tripolyphosphate, and sodium humate.

[0025] Preferably, the preparation steps of the MXene include:

[0026] S1. Lithium fluoride and hydrochloric acid are mixed in the first step to obtain a mixed solution;

[0027] S2. Under stirring, aluminum carbide and the mixed solution are mixed a second time to obtain a solution containing MXene;

[0028] S3. The MXene-containing solution is washed with water and centrifuged sequentially to obtain a precipitate;

[0029] S4. The precipitate is freeze-dried to obtain MXene.

[0030] In a preferred embodiment, the amount of hydrochloric acid used is 15-30 mL relative to 1 g of lithium fluoride, and the amount of aluminum carbide used is 0.8-1.2 g.

[0031] It should be noted that in the preparation of MXene in this invention, there are no special requirements for the conditions of the first mixing, as long as the lithium fluoride is completely dissolved. This will not be elaborated further here, and those skilled in the art should not understand it as a limitation of this invention.

[0032] Preferably, the conditions for the second mixing are: a temperature of 30-35°C and a time of 22-26 hours.

[0033] Preferably, before step (2), the elastic fibers are cleaned independently in acetone, anhydrous ethanol and water, and the ultrasonic cleaning time is 4-8 minutes for each.

[0034] Preferably, the amount of MXene used is 0.2-0.3 g per 100 mL of solvent. The inventors have found that, under this preferred embodiment, the elastic fibers obtained by the present invention exhibit superior near-infrared shielding performance and better mechanical properties.

[0035] Preferably, the amount of the dispersant is 0.4-0.5 g relative to 100 mL of solvent.

[0036] Preferably, the amount of dopamine hydrochloride used is 0.008-0.01 mol relative to 100 mL of solvent.

[0037] In a preferred embodiment, the dispersant is sodium hexametaphosphate. The inventors have discovered that, under this preferred embodiment, the elastic fibers obtained by the present invention exhibit superior near-infrared shielding performance and better mechanical properties.

[0038] Preferably, the styrene-ethylene-butene-styrene block copolymer contains 15-30 wt% styrene structural units, has a Shore A hardness of 50-60, and a melt index (230℃, 2.16Kg) of 210-220 g / min or a melt index (200℃, 5Kg) of 25-35 g / min. The inventors have found that, under this preferred embodiment, the elastic fiber obtained by the present invention exhibits superior near-infrared shielding performance and better mechanical properties.

[0039] Preferably, in step (1), the melt spinning step includes: melt extrusion, melt extrusion, receiving and winding; the temperature of melt extrusion and melt extrusion is 160-175℃.

[0040] More preferably, the melt spinning step further includes: filtering and metering in sequence before melt extrusion; the temperature of filtering and metering is 160-175°C.

[0041] It should be noted that in this invention, the steps of melt spinning are performed using methods conventional in the art, and will not be described in detail here. Those skilled in the art should not interpret this as a limitation of the invention.

[0042] Preferably, the receiving and winding temperatures are both 90-100°C, and the winding speed is 50-200 rpm. It should be noted that in this invention, the temperature varies in different areas of the melt spinning machine, and the speed of different rollers also varies during the winding process. Therefore, the melt spinning conditions are all achieved within the aforementioned ranges. Further details of this invention will not be elaborated upon here, and those skilled in the art should not construe this as a limitation of the invention.

[0043] Preferably, in step (2), the impregnation treatment is carried out under ultrasonic conditions, and the conditions of the impregnation treatment include: a temperature of 25-30°C and a time of 30-90 min.

[0044] As previously described, a second aspect of the present invention provides an elastic fiber capable of near-infrared shielding prepared by the method described in the first aspect.

[0045] As previously stated, a third aspect of the present invention provides the application of the near-infrared shielding elastic fiber described in the second aspect in the textile field.

[0046] The present invention will be described in detail below through embodiments.

[0047] In the following examples, unless otherwise specified, all experimental instruments, reagents, and raw materials involved are commercially available products, and all reagents are analytical grade products.

[0048] Styrene-ethylene-butene-styrene block copolymers: Model MD-1648, with a styrene structural unit content of 20wt%, Shore A hardness of 52, and melt index (230℃, 2.16Kg) of 220g / min, purchased from Kraton Pharmaceuticals, USA; Model YH-505, with a styrene structural unit content of 20wt%, Shore A hardness of 56, and melt index (200℃, 5Kg) of 30g / min, purchased from Sinopec Baling Petrochemical Company; Model YH-602, with a styrene structural unit content of 35wt%, and Shore A hardness of 80, purchased from Sinopec Baling Petrochemical Company.

[0049] Preparation Example 1

[0050] This preparation example illustrates that MXene is prepared according to the following steps in this invention.

[0051] S1. Mix 1g of lithium fluoride with 20ml of 9mol / L hydrochloric acid to obtain a mixed solution;

[0052] S2. Under stirring (stirring speed 200 rpm), 1 g of aluminum carbide is mixed with the mixed solution for a second time (temperature 35℃, time 24h) to obtain a solution containing MXene.

[0053] S3. The MXene-containing solution is washed with water and centrifuged (centrifugation speed is 3500 rpm) to obtain the precipitate;

[0054] S4. The precipitate is freeze-dried to obtain MXene.

[0055] Example 1

[0056] This embodiment illustrates that the near-infrared shielding elastic fiber of the present invention is prepared according to the formula and process parameters in Table 1 and the method described below.

[0057] Step 1: The styrene-ethylene-butene-styrene block copolymer is dried, melt-extruded, filtered, metered, melt-extruded, received, and wound to obtain elastic fibers; and MXene, dopamine hydrochloride, and a dispersant are mixed in the presence of a solvent to obtain an impregnation solution;

[0058] The drying conditions are: temperature 40°C, time 6 hours;

[0059] The temperature of the melt extrusion, filtration, metering, and melt extrusion is 160-175℃, the temperature of the receiving and winding is 90-100℃, and the winding speed is 50-200rpm.

[0060] Step 2: The elastic fibers are ultrasonically cleaned sequentially in acetone for 5 minutes, in anhydrous ethanol for 5 minutes, and in deionized water for 5 minutes.

[0061] Step 3: The ultrasonically cleaned elastic fibers are impregnated in the impregnation solution to obtain the near-infrared shielding elastic fibers.

[0062] Unless otherwise specified, the remaining examples follow a similar process to Example 1. The difference is that the formulations and process parameters used in each example are different, as detailed in Table 1 (Note: Parameters not listed in Table 1 are the same as those in Example 1).

[0063] Table 1

[0064]

[0065] Comparative Example 1

[0066] This comparative example follows a similar procedure to Example 1, except that no dispersant is used.

[0067] Everything else is the same as in Example 1.

[0068] An elastic fiber DS1 capable of near-infrared shielding was prepared.

[0069] Comparative Example 2

[0070] This comparative example was conducted using a similar procedure to Example 1, except that the amount of MXene used in this comparative example was 0.1g.

[0071] Everything else is the same as in Example 1.

[0072] The elastic fiber DS2, which can shield against near-infrared radiation, was prepared.

[0073] Comparative Example 3

[0074] This comparative example was conducted using a similar procedure to Example 1, except that the amount of MXene used in this comparative example was 0.5g.

[0075] Everything else is the same as in Example 1.

[0076] DS3, an elastic fiber capable of near-infrared shielding, was prepared.

[0077] Comparative Example 4

[0078] This comparative example was conducted using a similar procedure to Example 1, except that the amount of dispersant used in this comparative example was 0.8g.

[0079] Everything else is the same as in Example 1.

[0080] DS4 elastic fiber, which can shield against near-infrared radiation, was prepared.

[0081] Comparative Example 5

[0082] This comparative example follows a similar process to Example 1, except that an equal mass of lignin (model P-d3, manufactured by Shanghai Aladdin Biochemical Technology Co., Ltd.) is used in this comparative example to replace sodium hexametaphosphate in Example 1.

[0083] Everything else is the same as in Example 1.

[0084] DS5 elastic fiber, capable of near-infrared shielding, was prepared.

[0085] Test case

[0086] The near-infrared shielding elastic fibers prepared in the examples and comparative examples were tested using the same method, and the results are shown in Table 2.

[0087] 1. The tensile strength and elongation at break of the elastic fiber were determined using a universal mechanical property tester (model UTM4104, manufactured by Shenzhen Sansi Zongheng Technology Co., Ltd.).

[0088] 2. Observe the surface temperature of the elastic fiber using a near-infrared camera at 50℃ for 600 seconds. The lower the surface temperature, the stronger the near-infrared shielding ability.

[0089] 3. Using a universal mechanical property tester (model UTM4104, manufacturer: Shenzhen Sansi Zongheng Technology Co., Ltd.), the sample was stretched at a length of 5cm and a tensile speed of 500mm / min, with a stretch length of 200%, and then recovered at 500mm / min.

[0090] Table 2

[0091] project Tensile strength / MPa Elongation at break Surface observed temperature / °C Elastic recovery rate % Example 1 15.2 345.24％ 30.1 96 Example 2 14.7 338.42％ 31.8 97 Example 3 16.3 289.45％ 29.5 95 Example 4 14.5 330.11％ 32.3 95 Example 5 14.4 326.53％ 31.7 92 Example 6 18.3 280.66％ 32.2 93 Comparative Example 1 11.6 316.76％ 42.5 92 Comparative Example 2 11.4 298.54％ 43.3 89 Comparative Example 3 10.8 289.36％ 39.8 85 Comparative Example 4 11.9 312.58％ 41.5 91 Comparative Example 5 12.7 312.79％ 36.7 80

[0092] As can be seen from the results in Table 2, the elastic fiber obtained by using the present invention has better near-infrared shielding effect and excellent mechanical properties.

[0093] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method of making near infrared shieldable spandex characterized in that, The method includes: (1) The styrene-ethylene-butene-styrene block copolymer was successively dried and melt-spun to obtain elastic fibers; and In the presence of a solvent, MXene, dopamine hydrochloride and a dispersant are mixed to obtain an impregnation solution; (2) The elastic fiber is impregnated in an impregnation solution to obtain the near-infrared shielding elastic fiber; The solvent is a mixed solution of water and dimethylformamide with a volume ratio of 1:1-1.5; The amount of MXene used is 0.16-0.45 g relative to 100 mL of solvent, the amount of dispersant used is 0.3-0.75 g, and the amount of dopamine hydrochloride used is 0.008-0.01 mol. The dispersant is sodium hexametaphosphate.

2. The method of claim 1, wherein, The amount of MXene used is 0.2-0.3 g per 100 mL of solvent.

3. The method according to claim 1 or 2, characterized in that, The amount of the dispersant used is 0.4-0.5 g per 100 mL of solvent.

4. The method according to claim 1 or 2, characterized in that, The styrene-ethylene-butene-styrene block copolymer has a styrene structural unit content of 15-30 wt%, a Shore A hardness of 50-60, a melt index of 210-220 g / min at 230℃ and 2.16 kg, or a melt index of 25-35 g / min at 200℃ and 5 kg.

5. The method according to claim 1 or 2, characterized in that, In step (1), the melt spinning process includes: melt extrusion, melt extrusion, receiving and winding; the temperature of melt extrusion and melt extrusion is 160-175℃.

6. The method of claim 5, wherein, The receiving and winding temperatures are both 90-100℃, and the winding speed is 50-200rpm.

7. The method according to claim 1 or 2, characterized in that, In step (2), the impregnation treatment is carried out under ultrasonic conditions, and the conditions of the impregnation treatment include: temperature of 25-30℃ and time of 30-90min.

8. The near-infrared shielding elastic fiber prepared by the method according to any one of claims 1-7.

9. The application of the near-infrared shielding elastic fiber as described in claim 8 in the textile field.

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