Moisture-absorbing heat-generating and anti-static multifunctional acrylic fiber, and preparation method and application thereof

Abstract

The application relates to the technical field of fiber modification, and particularly discloses a moisture-absorbing, heat-releasing and antistatic multifunctional acrylic fiber as well as a preparation method and application thereof. The acrylic fiber is obtained through pretreatment, alkaline hydrolysis, acid neutralization, grafting of double bonds and crosslinking reaction of ordinary acrylic fiber. In the alkaline hydrolysis, the alkali liquor is one of sodium hydroxide, potassium hydroxide, sodium bicarbonate, potassium bicarbonate, sodium carbonate and potassium carbonate, and the mass concentration of alkali metal in the alkali liquor is 6-20%; in the acid neutralization, the acid solution is one of acetic acid and carbonic acid, and the mass concentration is 20-30%; in the grafting of double bonds, the addition amount of the nucleophilic reagent is 25-80% of the mass of the acrylic fiber, and the nucleophilic reagent is one of allylamine, diallylamine and methylallylamine; and in the crosslinking reaction, the mass concentration of the hydrophilic monomer solution is 25-40%. The obtained acrylic fiber has higher moisture absorption, stronger material combination stability, more persistent moisture absorption and heat release effect, and is almost not affected by the washing times.

Description

Technical Field

[0001] This invention relates to the field of fiber modification, specifically to a moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber, its preparation method, and its applications. Background Technology

[0002] Traditional methods of keeping warm, such as layering clothing like a "sandwich," primarily focus on insulating against cold air and preventing heat loss from the body. This is both inconvenient for movement and aesthetically unappealing. With technological advancements and improved living standards, people are no longer satisfied with passive warmth and have begun researching active heat-generating materials. Active heat-generating materials can be designed, heat up rapidly, and have controllable temperatures. Compared to traditional methods, active heat-generating fabrics achieve warmth while being lighter, more breathable, and allowing for greater freedom of movement. Furthermore, most winter thermal underwear generates a lot of static electricity during wear due to friction between garments or between clothing and skin, resulting in a poor wearing experience.

[0003] Numerous active heat-generating fiber technologies have emerged in the field, which can generally be categorized into five types based on their heating mechanisms: moisture-absorbing heat generation, far-infrared heat generation, electrical heat generation, chemical reaction exothermics, and phase change exothermics. Most thermal underwear sold on the market currently utilizes moisture-absorbing heat generation. This technology primarily works by allowing hydrophilic groups in the moisture-absorbing material to interact with water vapor in the surface microenvironment through hydrogen bonds, reducing the kinetic energy of the water vapor molecules. According to the law of conservation of energy, this kinetic energy is converted into heat energy, thus generating heat. In moisture-absorbing heat generation technology, the higher the moisture absorption rate, the stronger the heating effect. Currently, the most common fibers, from highest to lowest moisture absorption rate, are wool, viscose, cotton, nylon, acrylic, and polyester, with wool having the highest at 16% and viscose at 13%. Acrylic fiber, a common insulating component in thermal underwear, is known as "artificial wool" mainly because it is fluffy, soft, and elastic. It is often used in autumn and winter fabrics. However, the hydrophobic cyano group (-C≡N) in acrylic fiber results in poor moisture absorption, with a moisture absorption rate of only 2%, making it difficult to achieve good moisture absorption and heat generation. At the same time, it is also easy to generate static electricity in clothing.

[0004] Currently, common methods for enhancing the hygroscopicity of acrylic fibers include spinning, acid hydrolysis, alkaline hydrolysis, and finishing agents. Hygroscopic acrylic fibers obtained through blend spinning are mostly obtained by blending acrylic acid or acrylonitrile copolymers with polyacrylonitrile. However, the amount of monomer added is generally less than 15%, mainly to meet the mechanical and dyeing properties of the fiber. Adding too many hydrophilic monomers leads to significant process variations and alters the polymerization reaction. Alternatively, other hydrophilic substances can be grafted onto polyacrylonitrile through wet spinning, but the grafting quantity is limited, and hygroscopicity cannot be improved. Increasing the grafting quantity excessively will cause the fiber to harden and its color fastness to decrease. Spinning involves many auxiliaries, complex process conditions, and makes it difficult to control fiber properties and time-consuming. Acid hydrolysis requires a large amount of concentrated strong acid and has a long hydrolysis time. The C≡N in PAN fibers hydrolyzes under the catalysis of alkaline solutions. Compared to acidic hydrolysis, this process is safer and shorter. However, strict control of reaction conditions is crucial to prevent damage to the fiber structure, reduced order, and decreased crystallinity, which can lead to easy fiber breakdown and poor strength. Furthermore, alkaline hydrolysis yields fewer hydrophilic groups. Without appropriate measures to introduce more hydrophilic groups, achieving a high moisture regain rate will be difficult, resulting in unsatisfactory moisture absorption and heat dissipation. Finishing agents containing hydrophilic groups can introduce a large number of hydrophilic groups onto the acrylic fiber surface, significantly improving its moisture absorption. However, since the finishing agent is only physically adsorbed onto the fiber surface, its wash resistance is poor. Therefore, increasing the hydrophilic group content in hydrolyzed fibers to improve wash resistance without affecting fiber strength is the most important research direction.

[0005] In addition, static electricity is generated by friction between clothing or between clothing and the human body. Besides reducing wearing comfort, excessive accumulation of static electricity can also harm the body, such as affecting the central nervous system and causing cardiovascular diseases. Therefore, it needs to be eliminated. Currently, methods for antistatic fabrics include: 1) using antistatic finishing agents to increase the fabric's hydrophilicity; 2) chemical modification: introducing hydrophilic groups into yarns or fabrics or copolymerizing or grafting them with hydrophilic polymers; 3) blending or embedding metal fibers. The first two methods work by increasing the fabric's moisture absorption and reducing its insulation, thereby accelerating static electricity leakage. However, in dry environments or after multiple washes, post-treatment with finishing agents can reduce or diminish the antistatic effect. The third method is a physical antistatic method, and blending or embedding metal fibers can affect the elasticity of the yarn, thus affecting the fabric's elasticity and making it feel stiff. Because water has a high conductivity, it is necessary to improve the fabric's moisture absorption and increase the conductivity of polymer materials during the development of thermal underwear fabrics, thereby reducing the static electricity effect. Summary of the Invention

[0006] Based on this, the purpose of this invention is to address the shortcomings of existing technologies by providing a multifunctional acrylic fiber with moisture absorption, heat generation, and antistatic properties, as well as its preparation method and applications.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber is obtained by pretreatment of ordinary acrylic fiber, alkaline hydrolysis, acid neutralization, grafting to introduce double bonds, and crosslinking reaction, and has the following structural formula:

[0009]

[0010] Where R is hydrogen (H) or methyl (-CH3) or allyl (-CH2CHCH2), R' is hydrogen (H) or methyl (-CH3) or carboxymethyl (-CH2COOH), and R" is carboxyl (-COOH) or amide (-CONH2).

[0011] In the alkaline hydrolysis, the alkaline solution is one of sodium hydroxide, potassium hydroxide, sodium bicarbonate, potassium bicarbonate, sodium carbonate, and potassium carbonate, with an alkali metal concentration of 6%-20%. In the acid neutralization, the acid solution is one of acetic acid and carbonic acid, with a concentration range of 20%-30%, and the neutralization reaction time is 20-30 minutes. The reaction bath ratio between the acrylic fiber and the acid solution is 1:30. In the grafting to introduce double bonds, the amount of nucleophilic reagent added is 25%-80% of the mass of the acrylic fiber, and the nucleophilic reagent is one of allylamine, diallylamine, and methylallylamine. In the crosslinking reaction, the mass concentration of the hydrophilic monomer solution required is between 25%-40%, and the hydrophilic monomer includes one of acrylic acid, methacrylic acid, itaconic acid, and acrylamide.

[0012] As a further improvement of the present invention, the moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber has a moisture regain rate of up to 20.6%. When it is blended with viscose, cotton, and spandex to form fabric, the resulting fabric exhibits the following average temperature rise values ​​within 30 minutes after washing (before, after 30, and after 60 washes): 4.1℃, 4.0℃, and 4.0℃, respectively; the highest temperature rise values ​​are 8.8℃, 8.7℃, and 8.6℃, respectively; and the minimum antistatic half-life values ​​are 0.59s, 0.63s, and 0.60s, respectively. Furthermore, the bursting strength of the fabric woven using the modified acrylic fiber does not decrease significantly compared to the unmodified version.

[0013] A method for preparing a moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber includes the following steps:

[0014] Step 1: Acrylic fiber pretreatment; Select uniform PAN fibers as experimental raw materials, wash them with purified water, and dry them at 130℃ for later use;

[0015] Step 2: Alkaline hydrolysis of acrylic fibers; Weigh a certain amount of the above-mentioned acrylic fibers, place a solution composed of alkaline solutions and catalysts of different concentrations in a 200mL glass beaker, stir evenly, add the fibers, seal the mouth of the beaker with a sealing film, transfer it to a preheated water bath, add a magnetic stir bar, and stir at 150r / min to complete the alkaline hydrolysis of the acrylic fibers; The solution composition contains 80%-95% alkali solution by mass, 8%-20% catalyst, and the mass ratio of acrylic fibers to the solution is 1:30. The hydrolysis temperature is between 80-100℃, and the hydrolysis reaction time is between 15min-30min; The alkali metal concentration in the alkali solution is 6%-20% by mass.

[0016] Step 3: Acid Neutralization; After washing the hydrolyzed acrylic fibers from Step 2 twice with purified water, place them in an acid solution of a certain mass concentration for neutralization reaction, converting the carboxylates produced by hydrolysis into carboxylic acids. After the reaction, wash with water and dry for later use; the acid solution is either acetic acid or carbonic acid, with a mass concentration between 20% and 30%, and the neutralization reaction time is 20-30 minutes; the reaction bath ratio of the acrylic fibers to the acid solution is 1:30;

[0017] Step 4: Introducing double bonds by grafting onto acrylic fibers; dissolve the PPDP-Tf catalyst in 30 mL of dichloromethane solution, add the acrylic fibers from Step 3 and soak for 5 min, then add a nucleophile and graft at room temperature for 20 min. After the reaction, wash three times alternately with acetone and purified water, and dry at 130℃ for later use; the amount of nucleophile added is 25%-80% of the mass of the acrylic fibers.

[0018] Step 5: Crosslinking reaction; Dissolve the photoinitiator uniformly in an acetone solution of hydrophilic monomers, immerse the dried acrylic fiber from Step 4 in the above acetone solution of hydrophilic monomers, soak for 2-5 minutes, then remove the fiber, lay it flat on a flat table and perform roller treatment to remove excess solution, then perform crosslinking treatment under ultraviolet light for 2-5 minutes. After the reaction is completed, wash the fiber three times alternately with organic solvent acetone and purified water, and then dry it in an oven at 130℃ to obtain hygroscopic acrylic fiber;

[0019] The hydrophilic monomer solution has a mass concentration between 25% and 40%, and the photoinitiator accounts for 1% to 2% of the mass of the hydrophilic monomer solution.

[0020] Step Six: Fiber Performance Testing; Conduct moisture regain testing on the fibers;

[0021] Step 7: Fabric blending and performance testing; after blending modified acrylic fibers with other fibers, the fabric is woven and subjected to bursting strength testing, as well as moisture absorption and heat generation and antistatic performance testing before washing, and after 30 and 60 washes.

[0022] As a further improvement of the present invention, the alkaline solution in step two is one of sodium hydroxide, potassium hydroxide, sodium bicarbonate, potassium bicarbonate, sodium carbonate, and potassium carbonate.

[0023] As a further improvement of the present invention, ethanol is selected as the catalyst in step two.

[0024] As a further improvement of the present invention, the nucleophile in step four is one of allylamine, diallylamine, and methylallylamine.

[0025] As a further improvement of the present invention, the mass ratio of the catalyst PPDP-Tf is 25%-85% of the mass of the acrylic fiber.

[0026] As a further improvement of the present invention, the hydrophilic monomer in step five includes one of acrylic acid, methacrylic acid, itaconic acid, and acrylamide.

[0027] As a further improvement of the present invention, the photoinitiator in step five includes one of TPO, ITX, and BPO.

[0028] As a further improvement of the present invention, the moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber is used in clothing fabrics, especially in thermal underwear.

[0029] The beneficial effects of this invention are:

[0030] 1. This invention obtains a moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber by pretreating ordinary acrylic fiber, alkaline hydrolysis, acid neutralization, grafting to introduce double bonds, and cross-linking reaction. The moisture regain of this moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber is as high as 20.6%. When blended with viscose, cotton, and spandex to form fabrics, the average temperature rise of the fabric before washing, after 30 washes, and after 60 washes within 30 minutes is as follows: the highest average temperature rise is 4.1℃, 4.0℃, and 4.0℃, respectively, and the highest temperature rise is 8.8℃, 8.7℃, and 8.6℃, respectively. The minimum antistatic half-life is 0.59s, 0.63s, and 0.60s, respectively, and the bursting strength of the fabric shows almost no significant change.

[0031] 2. This invention modifies acrylic fibers through a three-step reaction. Compared to simple alkaline hydrolysis, the resulting acrylic fibers exhibit higher hygroscopicity, stronger material bonding stability, and more durable moisture absorption and heat generation effects, almost unaffected by the number of washes. Simultaneously, it significantly improves the material's antistatic properties.

[0032] 3. The present invention modifies acrylic fibers without significantly affecting the mechanical strength of the acrylic fibers before and after modification. This allows the fabric to maintain its original mechanical properties while retaining high moisture absorption and heat generation and high antistatic effect. This also reflects the mild and reasonable nature of the present invention.

[0033] 4. This invention has strong applicability and can also be applied to other yarns and fabrics containing acrylic fibers. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Appendix Figure 1 This is a schematic diagram of the chemical reaction of the present invention.

[0036] Appendix Figure 2 This is a comparison chart of the moisture regain of acrylic fibers in Examples 1-7 and Comparative Examples 1-2 of the present invention.

[0037] Appendix Figure 3 Comparison of moisture absorption and heat generation properties of fabrics woven from different acrylic fibers before and after washing.

[0038] Appendix Figure 4 Comparison of antistatic properties of fabrics woven from different acrylic fibers before and after washing.

[0039] Appendix Figure 5 A comparison chart showing the bursting strength of fabrics woven from acrylic fibers before and after modification. Detailed Implementation

[0040] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Example 1:

[0041] (1) Pretreatment of acrylic fiber: Uniform PAN fiber was manually selected as experimental material, washed with purified water and dried at 130℃ for later use.

[0042] (2) Alkaline hydrolysis of acrylic fiber: Weigh 2 g of the above acrylic fiber, put the mixture of 55 g of 6% NaOH solution and 5 g of anhydrous ethanol into a 200 mL glass beaker, stir manually until uniform, add the fiber and magnetic stir bar at the same time, seal the mouth of the beaker with a sealing film and transfer it to a water bath at 85 °C, stir at 150 r / min for 15 min to complete the alkaline hydrolysis of acrylic fiber.

[0043] (3) Acid neutralization: After rinsing the acrylonitrile fiber hydrolyzed in (2) above twice with purified water, place it in a 60 g solution with a mass concentration of 20% carbonic acid for 30 min to convert the carboxylate produced by hydrolysis into carboxylic acid. After the reaction is completed, wash it twice with water and dry it at 130 °C for later use.

[0044] (4) Introducing double bonds by grafting acrylonitrile fibers: Dissolve 1.7 g PPDP-Tf catalyst in 30 mL dichloromethane solution, add the fiber from (3) and soak for 5 min, then add 1.6 g diallylamine to the fiber and graft it at room temperature for 20 min. After the reaction, wash the fiber three times alternately with acetone and purified water, and dry it at 130 °C for later use.

[0045] (5) Crosslinking reaction: Dissolve 1 g of photoinitiator TPO uniformly in 50 g of acetone solution of itaconic acid monomer with a mass concentration of 35%, add it to the fiber in (4) and soak for 5 min. Take it out, lay it flat on a flat table and perform roller treatment to remove excess solution. Perform crosslinking treatment under ultraviolet light for 5 min. After the treatment, wash it three times with acetone and purified water alternately and then dry it in an oven at 130℃ to obtain hygroscopic acrylic fiber.

[0046] (6) Fiber performance test: The moisture regain of the fiber was tested and the moisture regain was 20.6%.

[0047] (7) Fabric blending and performance testing: Modified acrylic fiber was blended with other fibers and woven into fabric. The fabric was tested for moisture absorption and heat generation and antistatic properties before and after washing (30 times and 60 times). The average temperature rise of moisture absorption and heat generation within 30 minutes after washing was 4.1℃, 4.0℃ and 4.0℃, respectively, and the highest temperature rise was 8.8℃, 8.7℃ and 8.6℃, respectively. The antistatic half-lives were 0.60s, 0.59s and 0.63s, respectively. The average bursting strength of this fabric was 408N. Example 2:

[0048] (1) Pretreatment of acrylic fiber: Uniform PAN fiber was manually selected as experimental material, washed with double distilled water and dried at 130℃ for later use.

[0049] (2) Alkaline hydrolysis of acrylic fiber: Weigh 2 g of the above acrylic fiber, put the mixture of 55 g of 8% NaOH solution and 5 g of anhydrous ethanol into a 200 mL glass beaker, stir manually until uniform, add the fiber and magnetic stir bar at the same time, seal the mouth of the beaker with a sealing film and transfer it to a water bath at 85 °C, stir at 150 r / min for 15 min to complete the alkaline hydrolysis of acrylic fiber.

[0050] (3) Acid neutralization: After rinsing the acrylonitrile fiber hydrolyzed in (2) twice with purified water, place it in a 60 g solution with a mass concentration of 25% carbonic acid for 30 min to convert the carboxylate produced by hydrolysis into carboxylic acid. After the reaction is completed, wash it twice with water and dry it at 130 °C for later use.

[0051] (4) Introducing double bonds by grafting acrylic fiber: Dissolve 1.7g PPDP-Tf catalyst in 30mL dichloromethane solution, add fiber from (3) and soak for 5 min, then add 1.6g methylallylamine to the fiber and graft it for 20 min at room temperature. After the reaction, wash the fiber three times alternately with acetone and purified water, and dry it at 130℃ for later use.

[0052] (5) Crosslinking reaction: Dissolve 1 g of photoinitiator TPO uniformly in 50 g of acetone solution of itaconic acid monomer with a mass concentration of 30%, add (4) fiber and soak for 5 min, take it out, lay it flat on a flat table and perform roller treatment to remove excess solution, perform crosslinking treatment under ultraviolet light for 5 min, after the end, wash it 3 times with acetone and purified water alternately, and then dry it in an oven at 130℃ to obtain hygroscopic acrylic fiber.

[0053] (6) Fiber performance test: The moisture regain of the fiber was tested and the moisture regain was 19.3%.

[0054] (7) Fabric blending and performance testing: Modified acrylic fiber was blended with other fibers and woven into fabric. The fabric was tested for moisture absorption and heat generation and antistatic properties before and after washing (30 times and 60 times). The average temperature rise of moisture absorption and heat generation within 30 minutes after washing before, after 30 washes and after 60 washes was 3.9℃, 3.8℃ and 3.6℃, ​​respectively, and the highest temperature rise was 8.1℃, 7.9℃ and 8.0℃, respectively; the antistatic half-life was 0.75s, 0.79s and 0.83s, respectively, and the average bursting strength of this fabric was 414N. Example 3:

[0055] (1) Pretreatment of acrylic fiber: Uniform PAN fiber was manually selected as experimental material, washed with double distilled water and dried at 130℃ for later use.

[0056] (2) Alkaline hydrolysis of acrylic fiber: Weigh 2 g of the above acrylic fiber, put the mixture of 55 g of 6% NaOH solution and 5 g of anhydrous ethanol into a 200 mL glass beaker, stir manually until uniform, add the fiber and magnetic stir bar at the same time, seal the mouth of the beaker with a sealing film and transfer it to a water bath at 85 °C, stir at 150 r / min for 15 min to complete the alkaline hydrolysis of acrylic fiber.

[0057] (3) Acid neutralization: After rinsing the acrylonitrile fiber hydrolyzed in (2) twice with purified water, place it in 60 g of acetic acid solution with a mass concentration of 30% for 20 min to convert the carboxylate produced by hydrolysis into carboxylic acid. After the reaction is completed, wash it twice with water and dry it at 130 °C for later use.

[0058] (4) Introducing double bonds by grafting acrylonitrile fibers: Dissolve 1.3 g PPDP-Tf catalyst in 30 mL dichloromethane solution, add the fiber from (3) and soak for 5 minutes, then add 1.2 g diallylamine to carry out the grafting reaction at room temperature for 20 minutes. After the reaction, wash the fiber three times alternately with acetone and purified water, and dry it at 130℃ for later use.

[0059] (5) Crosslinking reaction: Dissolve 0.8 g of photoinitiator TPO uniformly in 50 g of acetone solution of acrylic monomer with a mass concentration of 35%, add the fiber from (4) and soak for 3 min, take it out, lay it flat on a flat table and perform roller treatment to remove excess solution, perform crosslinking treatment under ultraviolet light for 3 min, after which wash it three times with alternating acetone and purified water and dry it in an oven at 130℃ to obtain hygroscopic acrylic fiber.

[0060] (6) Fiber performance test: The moisture regain of the fiber was tested and the moisture regain was 19.0%.

[0061] (7) Fabric blending and performance testing: Modified acrylic fiber was blended with other fibers and woven into fabric. The moisture absorption and heat generation and antistatic properties of the fabric were tested before and after washing (30 times and 60 times). The average temperature rise of moisture absorption and heat generation within 30 minutes after washing before, after 30 washes and after 60 washes was 3.8℃, 3.8℃ and 3.6℃, ​​respectively, and the highest temperature rise was 8.0℃, 7.9℃ and 7.8℃, respectively; the antistatic half-life was 0.79s, 0.85s and 0.91s, respectively, and the average bursting strength of this fabric was 406N. Example 4:

[0062] (1) Pretreatment of acrylic fiber: Uniform PAN fiber was manually selected as experimental material, washed with double distilled water and dried at 130℃ for later use.

[0063] (2) Alkaline hydrolysis of acrylic fiber: Weigh 2 g of the above acrylic fiber, put the mixture of 50 g of 16% Na2CO3 solution and 10 g of anhydrous ethanol into a 200 mL glass beaker, stir manually until uniform, add the fiber and magnetic stir bar at the same time, seal the mouth of the beaker with a sealing film and transfer it to a water bath at 85 °C, stir at 150 r / min for 30 min to complete the alkaline hydrolysis of acrylic fiber.

[0064] (3) Acid neutralization: After rinsing the hydrolyzed acrylic fiber in step 2 twice with purified water, place it in 60 g of acetic acid solution with a mass concentration of 30% for 20 min to neutralize. After rinsing twice with purified water, dry it at 130℃ for later use.

[0065] (4) Introducing double bonds by grafting acrylic fibers: Dissolve 1.1 g PPDP-Tf catalyst in 30 mL dichloromethane solution, add the fiber from (3) and soak for 5 min, then add 1 g diallylamine to the fiber and graft it for 20 min at room temperature. After the reaction, wash the fiber three times alternately with acetone and purified water, and dry it at 130℃ for later use.

[0066] (5) Crosslinking reaction: Dissolve 0.5g of photoinitiator BPO uniformly in 50g of acetone solution of acrylic monomer with a mass concentration of 35%, add the fiber from (4) and soak for 3 min, then take it out, lay it flat on a flat table and perform roller treatment to remove excess solution, perform crosslinking treatment under ultraviolet light for 2 min, and after the treatment, place it in an oven at 130℃ to dry to obtain hygroscopic acrylic fiber.

[0067] (6) Fiber performance test: The moisture regain of the fiber was tested and the moisture regain was 17.9%.

[0068] (7) Fabric blending and performance testing: Modified acrylic fiber was blended with other fibers and woven into fabric. The fabric was tested for moisture absorption and heat generation and antistatic properties before and after washing (30 times and 60 times). The average temperature rise of moisture absorption and heat generation within 30 minutes after washing was 3.6℃, ​​3.5℃ and 3.5℃, respectively, and the highest temperature rise was 7.8℃, 8.0℃ and 7.7℃, respectively. The antistatic half-lives were 1.21s, 1.29s and 1.36s, respectively. The average bursting strength of this fabric was 398N. Example 5:

[0069] (1) Pretreatment of acrylic fiber: Uniform PAN fiber was manually selected as experimental material, washed with double distilled water and dried at 130℃ for later use.

[0070] (2) Alkaline hydrolysis of acrylic fiber: Weigh 2 g of the above acrylic fiber, put the mixture of 52 g of K2CO3 solution with a mass concentration of 16% and 8 g of anhydrous ethanol into a 200 mL glass beaker, stir manually until uniform, add the fiber and magnetic stir bar at the same time, seal the mouth of the beaker with a sealing film and transfer it to a water bath at 85 °C, stir at 150 r / min for 30 min to complete the alkaline hydrolysis of acrylic fiber.

[0071] (3) Acid neutralization: After rinsing the hydrolyzed acrylic fiber in step 2 twice with purified water, place it in 60 g of acetic acid solution with a mass concentration of 30% for 25 min to neutralize. After rinsing twice with purified water, dry it at 130℃ for later use.

[0072] (4) Introducing double bonds by grafting acrylic fibers: Dissolve 1.3 g PPDP-Tf catalyst in 30 mL dichloromethane solution, add the fiber from (3) and soak for 5 minutes, then add 1.2 g allylamine to carry out the grafting reaction at room temperature for 20 minutes. After the reaction, wash the fiber three times alternately with acetone and purified water, and dry it at 130℃ for later use.

[0073] (5) Crosslinking reaction: Dissolve 0.5 g of photoinitiator TPO uniformly in 50 g of acetone solution of 40% methacrylic acid monomer, add the fiber from (4) and soak for 2 min, then take it out, lay it flat on a flat table and perform roller treatment to remove excess solution, perform crosslinking treatment under ultraviolet light for 2 min, and after the treatment, place it in an oven at 130℃ to dry to obtain hygroscopic acrylic fiber.

[0074] (6) Fiber performance test: The moisture regain of the fiber was tested and the moisture regain was 16.8%.

[0075] (7) Fabric blending and performance testing: Modified acrylic fiber was blended with other fibers and woven into fabric. The moisture absorption and heat generation and antistatic properties of the fabric were tested before and after washing (30 times and 60 times). The average temperature rise of moisture absorption and heat generation within 30 minutes after washing before, after 30 washes and after 60 washes was 3.4℃, 3.3℃ and 3.3℃ respectively, and the maximum temperature rise was 7.5℃, 7.4℃ and 7.3℃ respectively; the antistatic half-life was 1.62s, 1.69s and 1.73s respectively, and the average bursting strength of this fabric was 413N. Example 6:

[0076] (1) Pretreatment of acrylic fiber: Uniform PAN fiber was manually selected as experimental material, washed with double distilled water and dried at 130℃ for later use.

[0077] (2) Alkaline hydrolysis of acrylic fiber: Weigh 2 g of the above acrylic fiber, put the mixture of 55 g of 20% K2CO3 solution and 5 g of anhydrous ethanol into a 200 mL glass beaker, stir manually until uniform, add the fiber and magnetic stir bar at the same time, seal the mouth of the beaker with a sealing film and transfer it to a water bath at 90 °C, stir at 150 r / min for 30 min to complete the alkaline hydrolysis of acrylic fiber.

[0078] (3) Acid neutralization: After rinsing the hydrolyzed acrylic fiber in step 2 twice with purified water, place it in 60g of acetic acid solution with a mass concentration of 25% for 25 min to neutralize, then wash it twice with water and dry it at 130℃ for later use.

[0079] (4) Introducing double bonds by grafting acrylonitrile fibers: Dissolve 0.6 g PPDP-Tf catalyst in 30 mL dichloromethane solution, add fiber from (3) and soak for 5 min, then add 0.6 g diallylamine to carry out grafting reaction at room temperature for 20 min. After the reaction is completed, wash with acetone and purified water three times alternately, and dry at 130℃ for later use.

[0080] (5) Crosslinking reaction: Dissolve 0.5 g of photoinitiator TPO uniformly in 50 g of acetone solution of methacrylic acid monomer with a mass concentration of 35%, add the fiber from (4) and soak for 2 min, then take it out, lay it flat on a flat table and perform roller treatment to remove excess solution, perform crosslinking treatment under ultraviolet light for 2 min, and after the treatment, place it in an oven at 130 ℃ to dry to obtain hygroscopic acrylic fiber.

[0081] (6) Fiber performance test: The moisture regain of the fiber was tested and the moisture regain was 15.9%.

[0082] (7) Fabric blending and performance testing: Modified acrylic fiber was blended with other fibers and woven into fabric. The moisture absorption and heat generation and antistatic properties of the fabric were tested before and after washing (30 times and 60 times). The average temperature rise of moisture absorption and heat generation within 30 minutes after washing before, after 30 washes and after 60 washes was 3.2℃, 3.1℃ and 3.1℃ respectively, and the highest temperature rise was 7.1℃, 7.3℃ and 7.1℃ respectively; the antistatic half-life was 1.89s, 1.95s and 1.98s respectively, and the average bursting strength of this fabric was 392N. Example 7:

[0083] (1) Pretreatment of acrylic fiber: Uniform PAN fiber was manually selected as experimental material, washed with double distilled water and dried at 130 ℃ for later use.

[0084] (2) Alkaline hydrolysis of acrylic fiber: Weigh 2 g of the above acrylic fiber, put the mixture of 55 g of 6% NaHCO3 solution and 5 g of anhydrous ethanol into a 200 mL glass beaker, stir manually until uniform, add the fiber and magnetic stir bar at the same time, seal the mouth of the beaker with a sealing film and transfer it to a water bath at 95 °C, stir at 150 r / min for 25 min to complete the alkaline hydrolysis of acrylic fiber.

[0085] (3) Acid neutralization: After rinsing the hydrolyzed acrylic fiber in step 2 twice with purified water, place it in 60g of acetic acid solution with a mass concentration of 20% for 30 min to neutralize the carboxylate produced by hydrolysis into carboxylic acid. After the reaction is completed, wash it twice with water and dry it at 130℃ for later use.

[0086] (4) Introducing double bonds by grafting acrylonitrile fibers: Dissolve 0.5 g of PPDP-Tf catalyst in 30 mL of dichloromethane solution, add the fiber from (3) and soak for 5 min, then add 0.5 g of diallylamine to the fiber and graft it for 20 min at room temperature. After the reaction is complete, wash the fiber three times with acetone and purified water alternately, and dry it at 130 °C for later use.

[0087] (5) Crosslinking reaction: Dissolve 0.5 g of photoinitiator ITX uniformly in 50 g of acetone solution of acrylamide monomer with a mass concentration of 25%, add (4) fiber and soak for 2 min, take it out, lay it flat on a flat table and perform roller treatment to remove excess solution, perform crosslinking treatment under ultraviolet light for 2 min, and after the treatment, place it in an oven at 130℃ to dry to obtain hygroscopic acrylic fiber.

[0088] (6) Fiber performance test: The moisture regain of the fiber was tested and the moisture regain was 14.3%.

[0089] (7) Fabric blending and performance testing: Modified acrylic fiber was blended with other fibers and woven into fabric. The fabric was tested for moisture absorption and heat generation and antistatic properties before and after washing (30 times and 60 times). The average temperature rise of moisture absorption and heat generation within 30 minutes after washing was 3.1℃, 3.0℃ and 3.0℃, respectively, and the highest temperature rise was 7.3℃, 7.2℃ and 6.9℃, respectively. The antistatic half-life was 2.11s, 2.16s and 2.35s, respectively. The average bursting strength of this fabric was 403N.

[0090] Comparative Example 1:

[0091] (1) Pretreatment of acrylic fiber: Uniform PAN fiber was manually selected as experimental material, washed with double distilled water and dried at 130℃ for later use.

[0092] (2) Alkaline hydrolysis of acrylic fiber: Weigh 2 g of the above acrylic fiber, put the mixture of 50 g of 16% Na2CO3 solution and 10 g of anhydrous ethanol into a 200 mL glass beaker, stir manually until uniform, add the fiber and magnetic stir bar at the same time, seal the mouth of the beaker with a sealing film and transfer it to a water bath at 85 °C, stir at 150 r / min for 30 min to complete the alkaline hydrolysis of acrylic fiber.

[0093] (3) Acid neutralization: After rinsing the hydrolyzed acrylic fibers from step 2 twice with purified water, place them in a 60g solution of 30% acetic acid for 20 min to neutralize the carboxylates produced by hydrolysis into carboxylic acids. After washing with deionized water, dry them in an oven at 130℃ to obtain hygroscopic acrylic fibers.

[0094] (4) Fiber performance test: The moisture regain of the fiber was tested and the moisture regain was 2.1%.

[0095] (5) Fabric blending and performance testing: Acrylic fiber was blended with other fibers and woven into fabric. The fabric was then tested for moisture absorption and heat generation and antistatic properties before and after washing (30 times and 60 times). The average temperature rise of moisture absorption and heat generation within 30 minutes after washing was 1.5℃, 1.3℃ and 1.3℃, respectively, and the maximum temperature rise was 4.1℃, 4.0℃ and 3.9℃, respectively. The antistatic half-life was 6.32s, 6.54s and 6.71s, respectively. The average bursting strength of this fabric was 398N.

[0096] Comparative Example 2:

[0097] (1) Pretreatment of acrylic fiber: Uniform PAN fiber was manually selected as experimental material, washed with double distilled water and dried at 130℃ for later use.

[0098] (2) Alkaline hydrolysis of acrylic fiber: Weigh 2 g of the above acrylic fiber, put the mixture of 55 g of 6% NaOH solution and 5 g of anhydrous ethanol into a 200 mL glass beaker, stir manually until uniform, add the fiber and magnetic stir bar at the same time, seal the mouth of the beaker with a sealing film and transfer it to a water bath at 85 °C, stir at 150 r / min for 15 min to complete the alkaline hydrolysis of acrylic fiber.

[0099] (3) Acid neutralization: After rinsing the hydrolyzed acrylic fibers from step 2 twice with purified water, place them in a 60g solution of 30% acetic acid for 20 min to neutralize the carboxylates produced by hydrolysis into carboxylic acids. After washing with deionized water, dry them in an oven at 130℃ to obtain hygroscopic acrylic fibers.

[0100] (4) Fiber performance test: The moisture regain of the fiber was tested and the moisture regain was 2.3%.

[0101] (5) Fabric blending and performance testing: Acrylic fiber was blended with other fibers and woven into fabric. The fabric was then tested for moisture absorption and heat generation and antistatic properties before and after washing (30 times and 60 times). The average temperature rise of moisture absorption and heat generation within 30 minutes after washing was 1.8℃, 1.6℃ and 1.6℃, respectively, and the maximum temperature rise was 4.4℃, 4.1℃ and 4.3℃, respectively. The antistatic half-life was 5.92s, 6.06s and 6.32s, respectively. The average bursting strength of this fabric was 410N.

[0102] Specifically, in the fiber performance test of this invention, the moisture regain of the fiber is tested. The moisture regain test is determined according to GB / T 6503-2017 "Test Method for Moisture Regain of Chemical Fibers": The hygroscopic polyacrylonitrile fiber is placed in a constant temperature and humidity chamber and equilibrated for more than 24 hours under standard atmospheric conditions (temperature 20℃, humidity 65%). Its wet weight is weighed, and the moisture regain of the hygroscopic polyacrylonitrile fiber is calculated. The calculation method is: W(%)=(M1–M2) / M1×100%.

[0103] In the formula: W represents the moisture regain, M1 represents the mass before water absorption, and M2 represents the mass after water absorption.

[0104] In fabric blending and performance testing, generally speaking, the higher the acrylic fiber content in a fabric, the better its warmth retention. Typically, a warm fabric needs an acrylic fiber content greater than 40% to achieve warmth. However, high acrylic fiber content can lead to excessive bulkiness, making the fabric too thick, bulky, and uncomfortable to wear, unsuitable for close-fitting thermal underwear. Viscose and cotton, as naturally absorbent fibers, can be combined with acrylic fiber to improve the fabric's moisture absorption and heat generation properties, as well as comfort, resulting in a lighter feel. Spandex, as an elastic fiber, has good elasticity, a good hand feel, and is not easily deformed, making it suitable for blending with other fibers. However, the more spandex added, the more expensive the fabric; usually, adding around 10% is sufficient to achieve good elasticity. This invention blends modified acrylic fiber with other fibers to create a warm fabric, with the fiber composition and proportions being 48% acrylic, 24% viscose, 21% cotton, and 7% spandex. The fabric's moisture absorption, heat generation, and antistatic properties were tested before and after washing (30 and 60 times). The moisture absorption and heat generation test was conducted according to GB / T 29866-2013 "Test Method for Moisture Absorption and Heat Generation Performance of Textiles": Three combined specimens were prepared for each sample. Each combined specimen consisted of two specimens measuring 60mm x 100mm, with the reverse sides of the specimens pressed together and sewn along three sides to form a bag-shaped insertion opening, thus forming a combined specimen. The sewing line should be parallel to the length or width direction of the fabric, and polyester sewing thread was used for plain sewing with a stitch density of 8 stitches / 2cm. The antistatic performance test was conducted according to GB / T 12703.1-2021 "Test Method for Electrostatic Properties of Textiles Part 1: Corona Charging Method": After the sample was conditioned to moisture equilibrium, five specimens with a size of (45±1)mm × (45±1)mm were cut. After the sample was destaticated, it was pressed tightly, and a voltage of -10kV was applied to the specimen for 30s. The voltage and the decay over time were recorded. The test results were expressed as the arithmetic mean of the half-life of the peak voltage of the five specimens.

[0105] In the bursting strength test, the bursting strength of the fabric made of acrylic fiber blend before and after modification was tested. The test standard was GB / T 19976-2005 "Determination of bursting strength of textiles - steel ball method": a spherical rod with a diameter of 38 mm was selected, and the spherical rod and clamp were installed on the testing machine. The speed of the testing machine was set to 300 mm / min ± 5 mm / min. The cut sample was placed with the reverse side facing the rod and clamped on the clamp. The instrument was started, and the test was performed 5 times at different positions of the sample. The maximum value of each test was recorded, and the average value was calculated as the average bursting strength.

[0106] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multifunctional acrylic fiber with moisture absorption, heat generation, and antistatic properties, characterized in that, The moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber is obtained by pretreatment of ordinary acrylic fiber, alkaline hydrolysis, acid neutralization, grafting to introduce double bonds, and cross-linking reaction, and has the following structural formula: ; Where R is hydrogen (H) or methyl (-CH3) or allyl (-CH2CHCH2), R' is hydrogen (H) or methyl (-CH3) or carboxymethyl (-CH2COOH), and R" is carboxyl (-COOH) or amide (-CONH2). In the alkaline hydrolysis, the alkaline solution is one of sodium hydroxide, potassium hydroxide, sodium bicarbonate, potassium bicarbonate, sodium carbonate, and potassium carbonate, with an alkali metal concentration of 6%-20%. In the acid neutralization, the acid solution is one of acetic acid and carbonic acid, with a concentration range of 20%-30%, and the neutralization reaction time is 20-30 minutes. The reaction bath ratio between the acrylic fiber and the acid solution is 1:

30. In the grafting to introduce double bonds, the amount of nucleophilic reagent added is 25%-80% of the mass of the acrylic fiber, and the nucleophilic reagent is one of allylamine, diallylamine, and methylallylamine. In the crosslinking reaction, the mass concentration of the hydrophilic monomer solution required is between 25%-40%, and the hydrophilic monomer includes one of acrylic acid, methacrylic acid, itaconic acid, and acrylamide. Crosslinking is carried out under ultraviolet light.

2. The moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber according to claim 1, characterized in that, The moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber has a moisture regain of 20.6%. When blended with viscose, cotton, and spandex to form fabrics, the average temperature rise during the 30-minute period after washing (before, after 30, and after 60 washes) is 4.1℃, 4.0℃, and 4.0℃, respectively, with the highest temperature rise values ​​being 8.8℃, 8.7℃, and 8.6℃, respectively. The minimum antistatic half-life values ​​can reach 0.59s, 0.63s, and 0.60s, respectively. Furthermore, the bursting strength of the fabric woven using the modified acrylic fiber does not decrease significantly compared to the unmodified version.

3. The preparation method of the moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber as described in claim 1, characterized in that, Includes the following steps: Step 1: Acrylic fiber pretreatment; Select uniform PAN fibers as experimental raw materials, wash them with purified water, and dry them at 130℃ for later use; Step 2: Alkaline hydrolysis of acrylic fibers; Weigh a certain amount of the above-mentioned acrylic fibers, place a solution composed of alkaline solutions and catalysts of different concentrations in a 200mL glass beaker, stir evenly, add the fibers, seal the mouth of the beaker with a sealing film, transfer it to a preheated water bath, add a magnetic stir bar, and stir at 150r / min to complete the alkaline hydrolysis of the acrylic fibers; The solution composition contains 80%-95% alkali solution by mass, 8%-20% catalyst, and the mass ratio of acrylic fibers to the solution is 1:

30. The hydrolysis temperature is between 80-100℃, and the hydrolysis reaction time is between 15min-30min; The alkali metal concentration in the alkali solution is 6%-20% by mass. Step 3: Acid Neutralization; After washing the hydrolyzed acrylic fibers from Step 2 twice with purified water, place them in an acid solution of a certain mass concentration for neutralization reaction, converting the carboxylates produced by hydrolysis into carboxylic acids. After the reaction, wash with water and dry for later use; the acid solution is either acetic acid or carbonic acid, with a mass concentration between 20% and 30%, and the neutralization reaction time is 20-30 minutes; the reaction bath ratio of the acrylic fibers to the acid solution is 1:30; Step 4: Introducing double bonds by grafting onto acrylic fibers; dissolve the PPDP-Tf catalyst in 30 mL of dichloromethane solution, add the acrylic fibers from Step 3 and soak for 5 min, then add a nucleophile and graft at room temperature for 20 min. After the reaction, wash three times alternately with acetone and purified water, and dry at 130℃ for later use; the amount of nucleophile added is 25%-80% of the mass of the acrylic fibers. Step 5: Crosslinking reaction; Dissolve the photoinitiator uniformly in an acetone solution of hydrophilic monomers, immerse the dried acrylic fiber from Step 4 in the above acetone solution of hydrophilic monomers, soak for 2-5 minutes, then remove the fiber, lay it flat on a flat table and perform roller treatment to remove excess solution, then perform crosslinking treatment under ultraviolet light for 2-5 minutes. After the reaction is completed, wash the fiber three times alternately with organic solvent acetone and purified water, and then dry it in an oven at 130℃ to obtain hygroscopic acrylic fiber; The hydrophilic monomer solution has a mass concentration between 25% and 40%, and the photoinitiator accounts for 1% to 2% of the mass of the hydrophilic monomer solution. Step Six: Fiber Performance Testing; Conduct moisture regain testing on the fibers; Step 7: Fabric blending and performance testing; Modified acrylic fiber is blended with viscose, cotton and spandex to form a fabric, and the fabric is subjected to bursting force test, as well as moisture absorption and heat generation and antistatic performance tests before washing, and after 30 and 60 washes.

4. The method for preparing the moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber according to claim 3, characterized in that, In step two, the alkaline solution is one of sodium hydroxide, potassium hydroxide, sodium bicarbonate, potassium bicarbonate, sodium carbonate, and potassium carbonate.

5. The method for preparing the moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber according to claim 3, characterized in that, In step two, ethanol is selected as the catalyst.

6. The method for preparing the moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber according to claim 3, characterized in that, The nucleophile in step four is one of allylamine, diallylamine, and methylallylamine.

7. The method for preparing the moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber according to claim 3, characterized in that, The catalyst PPDP-Tf has a mass ratio of 25%-85% of the acrylic fiber mass.

8. The method for preparing the moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber according to claim 3, characterized in that, The hydrophilic monomer in step five includes one of acrylic acid, methacrylic acid, itaconic acid, and acrylamide.

9. The method for preparing the moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber according to claim 3, characterized in that, The photoinitiator in step five includes one of TPO, ITX, and BPO.

10. The application of the moisture-absorbing, heat-generating, and antistatic multifunctional acrylic fiber according to any one of claims 1-2, or the fiber prepared by the preparation method according to any one of claims 3-9, in clothing fabrics.

11. The application according to claim 10, wherein the clothing fabric is thermal underwear.

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