A method for manufacturing a yarn having both water absorption and water repellency

Abstract

The application relates to the field of textile yarn preparation, and particularly discloses a preparation method of yarn with water absorption and waterproof double functions, water absorption and expansion fibers are prepared by taking PET fibers as a core layer and water absorption polymers as an outer layer, and then the water absorption and expansion fibers are twisted to obtain the yarn with water absorption and waterproof double functions; the water absorption polymers comprise the following raw materials in parts by weight: 70-80 parts of crosslinked polyacrylic acid sodium, 10-15 parts of sodium carboxymethyl cellulose, 5-10 parts of montmorillonite and 3-5 parts of polyvinyl alcohol. The fabric prepared by the application not only has the double functions of water absorption and waterproof, but also has the advantages of lightness, thinness and air permeability.

Description

Technical Field

[0001] This application relates to the field of textile yarn preparation, and more specifically, it relates to a method for preparing yarn with both water absorption and waterproof functions. Background Technology

[0002] As market demands become increasingly refined, people are placing more and more stringent requirements on the functional integration of yarns. They expect fabrics made from these yarns to possess excellent waterproof properties in rainy or humid environments, effectively preventing the penetration of external moisture; they also expect the yarns to quickly absorb sweat when the body sweats, and assist in transferring sweat to the outer layer of the fabric to keep the skin dry and improve wearing comfort. Especially in fields such as outdoor sports, medical protective equipment, and high-end apparel, these yarns, which can directly endow fabrics with both water-absorbing and waterproof functions, are the core foundation for upgrading fabric functionality and have broad application prospects.

[0003] In the early days, waterproof yarns were often made by coating the surface of regular fibers with synthetic materials such as PVC and PU to achieve a waterproof effect. While this treatment gave the yarn a certain degree of water resistance, allowing the fabric to block external moisture from penetrating, the coating layer would clog the fiber pores of the yarn itself, greatly limiting its breathability. As a result, when wearing fabrics woven from such yarns, the sweat produced by the human body could not be expelled as water vapor through the yarn pores, leading to a continuous increase in humidity inside the clothing and making people feel stuffy and uncomfortable. With the continuous advancement of technology, nanomaterials and composite fiber technologies are gradually being applied to the research and development of functional yarns. Among them, nano-modified yarns construct micron- to nano-scale microporous structures on the fiber surface, preventing liquid water molecules from passing through due to surface tension, while allowing gaseous water vapor molecules to pass through smoothly. This achieves a certain balance between waterproofing and breathability, resulting in fabrics with significantly improved comfort compared to earlier coated yarns. However, the core drawback of these nano-waterproof yarns lies in their lack of water absorption. Their microporous structure can only achieve water resistance and breathability, but cannot actively absorb sweat excreted by the human body. Sweat easily accumulates between the skin and the fabric, leading to a sticky feeling and failing to meet the need for dry wear. In the field of moisture-wicking yarns, early products mostly used single materials such as polyester fibers and regenerated cellulose fibers, relying on the fiber's own "wicking effect" to guide sweat from the skin side to the outer layer of the fabric to achieve a moisture-wicking effect. However, these single-material yarns have limited moisture absorption capacity and are completely lacking in waterproof performance. Once exposed to rain or a humid external environment, the yarn quickly absorbs external moisture and becomes saturated, making the clothing easily soaked and losing its original dryness.

[0004] Currently, while some products on the market achieve waterproofing and absorbency by using a composite weaving technique combining moisture-wicking and waterproof yarns in specific proportions, or by laminating or coating two fabrics together, such as the novel waterproof fabric disclosed in patent application CN108004777A, which includes an absorbent top layer and a waterproof inner lining layer, tightly bonded together by heat pressing, with a hydrophilic membrane coated on the outer surface of the top layer and a waterproof membrane coated on the inner lining layer's surface closest to the body, this new waterproof fabric, with its absorbent inner lining and waterproof outer layer, effectively absorbs sweat while reducing external moisture penetration, providing dual protection. However, these products, which achieve waterproofing and absorbency through laminating or coating two fabrics, suffer from being heavy and lacking breathability. Therefore, to meet the market's urgent need for lightweight, breathable, highly effective waterproof and absorbent fabrics, developing an innovative yarn with both waterproofing and absorbency is of paramount importance. Summary of the Invention

[0005] In order to develop a lightweight, breathable fabric with both waterproof and absorbent properties, this application provides a method for preparing a yarn with both absorbent and waterproof properties.

[0006] This application provides a method for preparing a yarn with dual functions of water absorption and waterproofing, using the following technical solution: A method for preparing a yarn with dual functions of water absorption and waterproofing, wherein water-absorbing and expanding fibers are prepared by using PET fibers as the core layer and water-absorbing polymers as the outer layer, and then the water-absorbing and expanding fibers are twisted to obtain a yarn with dual functions of water absorption and waterproofing; the water-absorbing polymer comprises the following raw materials in parts by weight: 70-80 parts of cross-linked sodium polyacrylate, 10-15 parts of sodium carboxymethyl cellulose, 5-10 parts of montmorillonite, and 3-5 parts of polyvinyl alcohol.

[0007] By adopting the above technical solution, this application uses PET as the core layer to provide basic strength and limit excessive expansion in the length direction of the yarn. Simultaneously, the composite structure formed by the water-absorbing polymer coating the core layer surface facilitates moisture penetration. When the water-absorbing and expanding fibers formed by the combination of these two are twisted to form functional yarns and then woven into fabric, it not only has good breathability, but also, upon contact with water, water molecules can be quickly absorbed by the water-absorbing and expanding yarns, causing a change in the yarn's volume. This changes the pores of the fabric, blocking further moisture penetration and creating a sealed state, resulting in a waterproof effect. The fabric prepared in this application not only has both water-absorbing and waterproof functions, but also consists of only one layer of fabric, eliminating the need for traditional bonding of two fabrics, and has the advantages of being lightweight and breathable.

[0008] Preferably, the cross-linked sodium polyacrylate is an inorganic-organic composite material prepared by reacting rare earth oxide nanoparticles modified with silane coupling agents with acrylic acid monomers.

[0009] By adopting the above technical solution, rare earth oxide nanoparticles can be dispersed in the network structure of sodium polyacrylate as physical cross-linking points. Due to the high specific surface area and surface active sites of rare earth nanoparticles, water molecules can be adsorbed, further improving the water absorption ratio and water retention capacity of cross-linked sodium polyacrylate. At the same time, rare earth oxides can improve the antibacterial properties of the yarn by releasing active oxygen to destroy bacterial cell membranes.

[0010] Preferably, the method for preparing the cross-linked sodium polyacrylate includes the following steps:

[0011] (1) Mix silane coupling agent with ethanol and deionized water and adjust pH to 4-5, stir to form an active solution; add rare earth oxide nanoparticles to the ethanol solution and ultrasonically disperse to form a uniform suspension; add the active solution dropwise to the suspension, heat to 50-80℃, stir for 4-8h, centrifuge, wash and dry to obtain modified rare earth oxide nanoparticles.

[0012] (2) Mix acrylic monomer with deionized water, add modified rare earth oxide nanoparticles, disperse by ultrasonication and adjust pH to 6-8, then add redox initiator solution and crosslinking agent, heat to 40-60℃ under inert gas atmosphere, stir reaction for 1-4h, gel is formed after reaction, wash and freeze dry to obtain crosslinked sodium polyacrylate composite material.

[0013] By adopting the above technical solution, this method achieves chemical bonding between nanoparticles and polymers through silane coupling agents, and combines the multifunctional properties (antibacterial and antioxidant) of rare earth elements to prepare high-performance cross-linked sodium polyacrylate.

[0014] Preferably, in step (1), the rare earth oxide nanoparticles are a mixture of cerium oxide and lanthanum oxide in a mass ratio of (1-3):1.

[0015] By adopting the above technical solution and using a mixture of cerium oxide and lanthanum oxide as a rare earth component, synergistic effects can be achieved through complementary performance: cerium oxide strengthens the interfacial covalent bonding, provides antioxidant properties and mechanical support due to its high reactivity, while lanthanum oxide assists in dispersion, enhances thermal stability and reduces costs through uniform charge distribution. The combination of the two not only optimizes the stability of the inorganic-organic interface but also improves the mechanical properties and anti-aging ability of the material.

[0016] Preferably, in step (1), the silane coupling agent is a mixture of γ-methacryloxypropyltrimethoxysilane and perfluorooctyltriethoxysilane in a mass ratio of (7-9):(1-3).

[0017] By adopting the above technical solution, γ-methacryloxypropyltrimethoxysilane (KH570) and perfluorooctyltriethoxysilane can be simultaneously and efficiently hydrolyzed to generate silanol groups under weakly acidic conditions of pH 4-5. These silanol groups then undergo a condensation reaction with the hydroxyl groups on the surface of rare earth oxide nanoparticles to achieve a firm bond. KH570 undergoes a copolymerization reaction with acrylic monomers through carbon-carbon double bonds in its molecule, chemically anchoring the nanoparticles in the sodium polyacrylate network to ensure dispersion stability and mechanical strength. Perfluorooctyltriethoxysilane introduces uniform hydrophobic microregions through perfluoroalkyl groups to improve water permeability resistance after water absorption. The combination of the two in this ratio not only avoids the agglomeration and detachment of nanoparticles by leveraging the dominant role of KH570, but also achieves a balance between hydrophobicity and hydrophilicity through an appropriate amount of perfluorosilane, ultimately synergistically improving the water absorption and waterproofing functions of the cross-linked sodium polyacrylate composite material.

[0018] Preferably, the method for preparing the water-absorbing and swelling fiber includes the following steps:

[0019] S1, Mix the raw materials of the water-absorbing polymer in proportion and dissolve them in deionized water to form a coating solution;

[0020] S2, Immerse the PET filament in the coating solution and draw it through the coating solution to obtain coated fibers;

[0021] S3 involves using electron beam radiation to crosslink and cure the coated fiber, followed by drying to obtain water-absorbing and swelling fibers.

[0022] By adopting the above technical solution, the above preparation method involves preparing a coating liquid from water-absorbing polymer raw materials, allowing PET filaments to be dipped and coated to form a core-shell structure prototype, and then cross-linked and cured by electron beam radiation to form a stable three-dimensional network and dried and shaped, thereby achieving a synergistic combination of the PET core layer and the water-absorbing polymer outer layer. This preparation method is simple, continuous, and efficient. Electron beam cross-linking ensures the stability of the core-shell structure and the water resistance of the outer layer. Furthermore, the water absorption performance can be flexibly controlled by adjusting the parameters of the coating liquid. At the same time, water is used as a solvent, eliminating the need for a large amount of chemical cross-linking agents, which is both environmentally friendly and suitable for raw material applicability, making it suitable for large-scale production.

[0023] Preferably, the raw materials for the water-absorbing polymer also include 2-5 parts by weight of nanocellulose.

[0024] By adopting the above technical solution, the fibrous structure of nanocellulose and its abundant hydroxyl groups on the surface form a dense hydrogen bond network with the carboxyl groups of cross-linked sodium polyacrylate and the hydroxyl groups of polyvinyl alcohol. At the same time, it interweaves with the two-dimensional layered structure of montmorillonite to strengthen the skeleton. This can significantly improve the mechanical strength and structural stability of the water-absorbing polymer, avoid breakage or deformation caused by excessive swelling after water absorption, inhibit the agglomeration of other fillers through hydrogen bonding, optimize the uniformity of coating liquid dispersion, and not hinder water molecule penetration. While maintaining or even synergistically improving the polymer's water absorption rate, it reduces the water loss rate after water absorption. It can also synergistically enhance the interfacial bonding force between the coating layer and the PET core layer with other components, and improve the weaving adaptability and service durability of the final yarn.

[0025] Preferably, the raw materials for the water-absorbing polymer also include 1-3 parts by weight of sodium alginate.

[0026] By employing the above technical solution, the carboxyl group in sodium alginate molecules can react with the Ce group on the surface of rare earth oxide nanoparticles. 3+ La 3+ It forms stable chelates, and its hydroxyl groups can form a dense hydrogen bond network with the hydroxyl groups of nanocellulose and polyvinyl alcohol. It is also rich in hydrophilic groups that can participate in the water absorption process. It can inhibit the aggregation of rare earth oxide nanoparticles through chelation, form dual stability with chemical bonding with silane coupling agents, and enhance the structural stability and gel strength of water-absorbing polymers and the gel strength after water absorption by means of hydrogen bond network with fillers such as nanocellulose and montmorillonite, so as to avoid excessive swelling and deformation. It can also synergistically improve the water absorption rate and salt resistance of polymers.

[0027] Preferably, in S2, the PET filament is pretreated before being immersed in the coating solution, specifically by performing plasma etching on the PET filament and then immersing it in a 0.5wt% polyvinyl alcohol aqueous solution to obtain pretreated PET filament.

[0028] By employing the above technical solution, plasma etching breaks the chemical bonds on the surface of PET filaments using high-energy particles, introducing polar groups such as hydroxyl and carboxyl groups and forming a micro-rough structure, thereby achieving surface activation and enhanced hydrophilicity. Subsequently, the filaments are immersed in a PVA aqueous solution, where hydrogen bonds are formed between the hydroxyl groups in the PVA molecules and the polar groups on the PET surface, uniformly adhering an ultrathin PVA film containing a large number of hydroxyl groups. This "polar gradient transition" bridges the hydrophobic PET and the hydrophilic coating solution, providing excellent chemical bonding sites and wettability for subsequent coating. The two form a synergistic system of "surface activation-polar bridging," effectively solving the interface compatibility problem and ensuring the stability of the core-shell structure.

[0029] This pretreatment significantly improves the interfacial bonding between PET filaments and the water-absorbing polymer coating solution, reducing the risk of coating peeling. Through the synergy of plasma roughening and PVA molding properties, the coating solution is mixed and covered evenly, avoiding localized missed coating or aggregation. At the same time, shallow surface etching and ultra-thin PVA film do not damage the PET body structure, fully preserving its mechanical support properties, thus ensuring the core-shell structure stability and subsequent processing performance of the water-absorbing and swelling yarn.

[0030] Preferably, in S2, the PET filament is pretreated before being immersed in the coating solution. Specifically, after plasma etching, the PET filament is first immersed in a 1wt% dopamine aqueous solution and then immersed in a 0.5wt% polyvinyl alcohol aqueous solution to obtain pretreated PET filament.

[0031] By adopting the above technical solution, a 1wt% dopamine aqueous solution impregnation step is introduced between plasma etching and polyvinyl alcohol (PVA) solution impregnation. Plasma etching generates active groups such as hydroxyl and carboxyl groups on the surface of PET filaments. Dopamine molecules can form covalent bonds with these active groups through catechol groups, forming a uniform polydopamine transition layer on the PET surface. The amino and catechol groups of this transition layer can form hydrogen bonds with the hydroxyl groups in the subsequent PVA aqueous solution. At the same time, they can also generate electrostatic interactions and hydrogen bonds with the hydroxyl groups of nanocellulose and the carboxyl groups of sodium alginate in the coating solution. This constructs a multi-interface bridge of PET-polydopamine-PVA-water-absorbing polymer, which significantly improves the interfacial bonding force between the coating layer and the PET core layer, preventing the outer layer from falling off during use. At the same time, the polydopamine transition layer can compensate for the defect of easy decay of active groups in simple plasma etching, enhance the stability of the pretreatment effect, and can also work synergistically with other functional components in the coating solution (such as modified rare earth oxides and nanocellulose) to further improve the structural integrity and durability of the water-absorbing and swelling fiber.

[0032] In summary, this application has the following beneficial effects:

[0033] 1. This application uses yarn woven from PET fiber as the core layer and water-absorbing polymer as the outer layer to form a fabric. It not only has the dual functions of water absorption and waterproofing, but also consists of only one layer of fabric. There is no traditional bonding of two fabrics, which has the advantages of being lightweight and breathable.

[0034] 2. The cross-linked sodium polyacrylate of this application is an inorganic-organic composite material prepared by reacting rare earth oxide nanoparticles modified with silane coupling agents with acrylic acid monomers. The rare earth oxide nanoparticles can be dispersed in the network structure of sodium polyacrylate as physical cross-linking points. Due to the high specific surface area and surface active sites of rare earth nanoparticles, water molecules can be adsorbed, which further improves the water absorption rate and water retention capacity of cross-linked sodium polyacrylate. At the same time, rare earth oxides can improve the antibacterial properties of the fabric by releasing active oxygen to destroy bacterial cell membranes.

[0035] 3. This application adds an appropriate amount of nanocellulose to the water-absorbing polymer. Due to its fibrous structure and abundant hydroxyl groups, it forms a hydrogen bond network with related components and interweaves with montmorillonite, which synergistically improves the mechanical properties, dispersibility, water absorption rate and interfacial bonding force of the water-absorbing polymer, and enhances the durability of the yarn.

[0036] 4. This application improves the water absorption rate and salt resistance of water-absorbing polymers by adding an appropriate amount of sodium alginate to the water-absorbing polymer. Sodium alginate forms a hydrogen bond network by chelating rare earth oxides with carboxyl groups and hydroxyl groups, which inhibits aggregation, strengthens the structure, and prevents swelling. Detailed Implementation

[0037] The present application will be further described in detail below with reference to the embodiments. Unless otherwise specified, all raw materials involved in the present application can be obtained commercially.

[0038] Preparation Examples 1-7: Cross-linked Sodium Polyacrylate

[0039] Preparation Example 1

[0040] This preparation example discloses a method for preparing cross-linked sodium polyacrylate, specifically including the following steps: 100g of acrylic monomer and 100ml of deionized water are stirred at 300rpm for 10min to mix evenly, the pH is adjusted to 7 with 1M sodium hydroxide solution, nitrogen gas is introduced for 30min and maintained, then a redox initiator and 0.5g of N,N'-methylenebisacrylamide (MBA) are added dropwise at a rate of 1 drop / s, the temperature is raised to 50℃, and the reaction is stirred for 2.5h. After the reaction is completed, a gel is formed, the gel is cut into the desired shape, soaked in deionized water for 24h, and freeze-dried at -50℃ for 48h to obtain the cross-linked sodium polyacrylate composite material; wherein, the redox initiator is obtained by dissolving 0.6g of ammonium persulfate and 0.6g of sodium bisulfite in 5ml of deionized water and mixing evenly.

[0041] Preparation Example 2

[0042] This preparation example discloses a method for preparing cross-linked sodium polyacrylate, specifically including the following steps:

[0043] (1) 2g of γ-methacryloxypropyltrimethoxysilane (KH570) was mixed with 30g of ethanol and 1g of deionized water, and 1M hydrochloric acid solution was added to adjust the pH to 4.5. The mixture was stirred at room temperature for 1h to form an active solution. 100g of cerium oxide with a particle size of 20-50nm was added to 1.5L of 90wt% ethanol solution and ultrasonically dispersed to form a uniform suspension. The active solution was added dropwise to the suspension, the temperature was raised to 65℃, and the reaction was stirred for 6h. After the reaction was completed, the mixture was centrifuged at 10000rpm for 10min, washed 3 times with ethanol, and vacuum dried at 60℃ for 12h to obtain modified rare earth oxide nanoparticles.

[0044] (2) Mix 100g of acrylic monomer and 100ml of deionized water at 300rpm for 10min. Add 12.5g of modified rare earth oxide nanoparticles and ultrasonically disperse for 20min. Adjust the pH to 7 with 1M sodium hydroxide solution. Purge with nitrogen for 30min and keep purging with nitrogen. Then add redox initiator and 0.5g of N,N'-methylenebisacrylamide (MBA) at a rate of 1 drop / s. Heat to 50℃ and stir for 2.5h. After the reaction is complete, a gel is formed. Cut the gel into the desired shape, soak in deionized water for 24h, and freeze dry at -50℃ for 48h to obtain cross-linked sodium polyacrylate composite material. The redox initiator is obtained by dissolving 0.6g of ammonium persulfate and 0.6g of sodium bisulfite in 5ml of deionized water and mixing them evenly.

[0045] Preparation Example 3

[0046] This preparation example is basically the same as preparation example 2, except that in step (1), 100g of cerium oxide is replaced with 100g of lanthanum oxide.

[0047] Preparation Example 4

[0048] This preparation example is basically the same as preparation example 2, except that in step (1), 100g of cerium oxide is replaced with 33g of lanthanum oxide and 67g of cerium oxide.

[0049] Preparation Example 5

[0050] This preparation example is basically the same as preparation example 4, except that in step (1), 2g of γ-methacryloxypropyltrimethoxysilane (KH570) is replaced with 1.6g of γ-methacryloxypropyltrimethoxysilane (KH570) and 0.4g of perfluorooctyltriethoxysilane.

[0051] Preparation Example 6

[0052] This preparation example discloses a method for preparing cross-linked sodium polyacrylate, specifically including the following steps:

[0053] (1) Mix 0.7g γ-methacryloxypropyltrimethoxysilane (KH570), 0.3g perfluorooctyltriethoxysilane with 15g ethanol and 0.5g deionized water evenly, and add 1M hydrochloric acid solution to adjust the pH to 4. Stir at room temperature for 1h to form an active solution; add 75g cerium oxide and 25g lanthanum oxide with a particle size of 20-50nm to 1.5L 90wt% ethanol solution and ultrasonically disperse to form a uniform suspension; add the active solution dropwise to the suspension, heat to 50℃, stir for 8h, and after the reaction is completed, centrifuge at 10000rpm for 10min, wash with ethanol 3 times, and vacuum dry at 60℃ for 12h to obtain modified rare earth oxide nanoparticles;

[0054] (2) Mix 100g of acrylic monomer and 100ml of deionized water at 300rpm for 10min. Add 5g of modified rare earth oxide nanoparticles and ultrasonically disperse for 20min. Adjust the pH to 6 with 1M sodium hydroxide solution. Purge with nitrogen for 30min and keep purging with nitrogen. Then add redox initiator and 0.1g of N,N'-methylenebisacrylamide (MBA) at a rate of 1 drop / s. Heat to 40℃ and stir for 4h. After the reaction is complete, a gel is formed. Cut the gel into the desired shape, soak in deionized water for 24h, and freeze dry at -50℃ for 48h to obtain cross-linked sodium polyacrylate composite material. The redox initiator is obtained by dissolving 0.25g of ammonium persulfate and 0.25g of sodium bisulfite in 2ml of deionized water and mixing them evenly.

[0055] Preparation Example 7

[0056] This preparation example discloses a method for preparing cross-linked sodium polyacrylate, specifically including the following steps:

[0057] (1) 2.7g of γ-methacryloxypropyltrimethoxysilane (KH570), 0.3g of perfluorooctyltriethoxysilane, 45g of ethanol and 1.5g of deionized water were mixed evenly, and 1M hydrochloric acid solution was added to adjust the pH to 5. The mixture was stirred at room temperature for 1h to form an active solution. 100g of cerium oxide with a particle size of 20-50nm was added to 1.5L of 90wt% ethanol solution and ultrasonically dispersed to form a uniform suspension. The active solution was added dropwise to the suspension, the temperature was raised to 80℃, and the reaction was stirred for 4h. After the reaction was completed, the mixture was centrifuged at 10000rpm for 10min, washed 3 times with ethanol, and vacuum dried at 60℃ for 12h to obtain modified rare earth oxide nanoparticles.

[0058] (2) Mix 100g of acrylic monomer and 100ml of deionized water at 300rpm for 10min. Add 20g of modified rare earth oxide nanoparticles and ultrasonically disperse for 20min. Adjust the pH to 8 with 1M sodium hydroxide solution. Purge with nitrogen for 30min and keep purging with nitrogen. Then add redox initiator and 1g of N,N'-methylenebisacrylamide (MBA) at a rate of 1 drop / s. Heat to 60℃ and stir for 1h. After the reaction is complete, a gel is formed. Cut the gel into the desired shape, soak in deionized water for 24h, and freeze dry at -50℃ for 48h to obtain cross-linked sodium polyacrylate composite material. The redox initiator is obtained by dissolving 1g of ammonium persulfate and 1g of sodium bisulfite in 8ml of deionized water and mixing them evenly.

[0059] Example 1

[0060] This embodiment provides a method for preparing yarn with both water absorption and waterproof functions, including the following steps:

[0061] 75g of cross-linked sodium polyacrylate, 13g of sodium carboxymethyl cellulose, 8g of montmorillonite, and 4g of polyvinyl alcohol were added to 400ml of deionized water and mixed evenly to form a coating solution. 100dtex PET filaments were immersed in the coating solution, and coated fibers were obtained by controlling the gap between the drive roller and the metering roller to be 100μm and stretching them at a speed of 5m / min. The coated fibers were cured by electron beam irradiation with a dose of 80kGy under nitrogen protection. After curing, they were treated in a hot air drying oven at 60℃ for 30min to obtain water-absorbing and swellable fibers. The water-absorbing and swellable fibers were twisted to obtain functional yarns. The cross-linked sodium polyacrylate was obtained from Preparation Example 1.

[0062] This embodiment also provides a method for preparing a fabric with both water absorption and waterproof functions, specifically: using the obtained functional yarns as warp and weft yarns, with a warp and weft density of 40 yarns / cm, and forming a plain weave fabric by machine weaving.

[0063] Example 2

[0064] This embodiment is basically the same as Embodiment 1, except that this embodiment provides a method for preparing a yarn with both water absorption and waterproof functions, including the following steps:

[0065] 75g of cross-linked sodium polyacrylate, 13g of sodium carboxymethyl cellulose, 8g of montmorillonite, 4g of polyvinyl alcohol, and 4g of nanocellulose were added to 400ml of deionized water and mixed evenly to form a coating solution. 100dtex PET filaments were immersed in the coating solution, and coated fibers were obtained by controlling the gap between the drive roller and the metering roller to be 100μm and stretching them at a speed of 5m / min. The coated fibers were cured by electron beam irradiation with a dose of 80kGy under nitrogen protection. After curing, they were treated in a hot air drying oven at 60℃ for 30min to obtain water-absorbing and swellable fibers. The water-absorbing and swellable fibers were twisted to obtain functional yarns. The cross-linked sodium polyacrylate was obtained from Preparation Example 1.

[0066] Example 3

[0067] This embodiment is basically the same as Embodiment 1, except that this embodiment provides a method for preparing a yarn with both water absorption and waterproof functions, including the following steps:

[0068] 75g of cross-linked sodium polyacrylate, 13g of sodium carboxymethyl cellulose, 8g of montmorillonite, 4g of polyvinyl alcohol, 4g of nanocellulose, and 2g of sodium alginate were added to 400ml of deionized water and mixed evenly to form a coating solution. 100dtex PET filaments were immersed in the coating solution, and coated fibers were obtained by controlling the gap between the drive roller and the metering roller to be 100μm and stretching at a speed of 5m / min. The coated fibers were cured by electron beam irradiation with a dose of 80kGy under nitrogen protection. After curing, they were treated in a hot air drying oven at 60℃ for 30min to obtain water-absorbing and swellable fibers. The water-absorbing and swellable fibers were twisted to obtain functional yarns. The cross-linked sodium polyacrylate was obtained from Preparation Example 1.

[0069] Example 4

[0070] This embodiment is basically the same as Embodiment 3, except that this embodiment provides a method for preparing a yarn with both water absorption and waterproof functions, including the following steps:

[0071] 70g of cross-linked sodium polyacrylate, 15g of sodium carboxymethyl cellulose, 10g of montmorillonite, 5g of polyvinyl alcohol, 2g of nanocellulose, and 1g of sodium alginate were added to 400ml of deionized water and mixed evenly to form a coating solution. 100dtex PET filaments were immersed in the coating solution, and coated fibers were obtained by controlling the gap between the drive roller and the metering roller to be 100μm and stretching at a speed of 5m / min. The coated fibers were cured by electron beam irradiation with a dose of 80kGy under nitrogen protection. After curing, they were treated in a hot air drying oven at 60℃ for 30min to obtain water-absorbing and swellable fibers. The water-absorbing and swellable fibers were twisted to obtain functional yarns. The cross-linked sodium polyacrylate was obtained from Preparation Example 1.

[0072] Example 5

[0073] This embodiment is basically the same as Embodiment 3, except that this embodiment provides a method for preparing a yarn with both water absorption and waterproof functions, including the following steps:

[0074] 80g of cross-linked sodium polyacrylate, 10g of sodium carboxymethyl cellulose, 5g of montmorillonite, 5g of polyvinyl alcohol, 5g of nanocellulose, and 3g of sodium alginate were added to 400ml of deionized water and mixed evenly to form a coating solution. 100dtex PET filaments were immersed in the coating solution, and coated fibers were obtained by controlling the gap between the drive roller and the metering roller to be 100μm and stretching at a speed of 5m / min. The coated fibers were cured by electron beam irradiation with a dose of 80kGy under nitrogen protection. After curing, they were treated in a hot air drying oven at 60℃ for 30min to obtain water-absorbing and swellable fibers. The water-absorbing and swellable fibers were twisted to obtain functional yarns. The cross-linked sodium polyacrylate was obtained from Preparation Example 1.

[0075] Example 6

[0076] This embodiment is basically the same as Example 3, except that the cross-linked sodium polyacrylate is the one obtained in Preparation Example 2.

[0077] Example 7

[0078] This embodiment is basically the same as Example 3, except that the cross-linked sodium polyacrylate is the one obtained in Preparation Example 3.

[0079] Example 8

[0080] This embodiment is basically the same as Example 3, except that the cross-linked sodium polyacrylate is the one obtained in Preparation Example 4.

[0081] Example 9

[0082] This embodiment is basically the same as Example 3, except that the cross-linked sodium polyacrylate is the one obtained in Preparation Example 5.

[0083] Example 10

[0084] This embodiment is basically the same as Example 3, except that the cross-linked sodium polyacrylate is the one obtained in Preparation Example 6.

[0085] Example 11

[0086] This embodiment is basically the same as Example 3, except that the cross-linked sodium polyacrylate is the one obtained in Preparation Example 7.

[0087] Example 12

[0088] This embodiment is basically the same as Embodiment 3, except that this embodiment provides a method for preparing a yarn with both water absorption and waterproof functions, including the following steps:

[0089] 100 dtex PET filaments were plasma-treated at 300 W for 30 s, then immersed in a 0.5 wt% PVA aqueous solution at 50 °C for 10 s, and dried in a 60 °C hot air drying oven for 1 min to obtain pretreated PET filaments. 75 g of cross-linked sodium polyacrylate, 13 g of sodium carboxymethyl cellulose, 8 g of montmorillonite, 4 g of polyvinyl alcohol, 4 g of nanocellulose, and 2 g of sodium alginate were added to 400 ml of deionized water and mixed evenly to form a coating solution. The pretreated PET filaments were immersed in the coating solution, and the gap between the drive roller and the metering roller was controlled to be 100 μm, and the fibers were stretched at a speed of 5 m / min to obtain coated fibers. The coated fibers were cured by electron beam irradiation at a dose of 80 kGy under nitrogen protection, and then treated in a 60 °C hot air drying oven for 30 min to obtain water-absorbing and swellable fibers. The water-absorbing and swellable fibers were twisted to obtain functional yarns. The cross-linked sodium polyacrylate was obtained from Preparation Example 1.

[0090] Example 13

[0091] This embodiment is basically the same as Embodiment 3, except that this embodiment provides a method for preparing a yarn with both water absorption and waterproof functions, including the following steps:

[0092] 100 dtex PET filaments were plasma-treated at 300 W for 30 seconds, then immersed in a 1 wt% dopamine aqueous solution at 25°C and pH 8 for 60 minutes, followed by immersion in a 0.5 wt% PVA aqueous solution at 50°C for 10 seconds, and finally dried in a 60°C hot air drying oven for 1 minute to obtain pretreated PET filaments. 75 g of cross-linked sodium polyacrylate, 13 g of sodium carboxymethyl cellulose, 8 g of montmorillonite, 4 g of polyvinyl alcohol, 4 g of nanocellulose, and 2 g of sodium alginate were added to 400 m... A coating solution is formed by uniformly mixing deionized water; pretreated PET filaments are immersed in the coating solution, and coated fibers are obtained by controlling the gap between the drive roller and the metering roller to be 100 μm and stretching at a speed of 5 m / min; the coated fibers are cured by electron beam irradiation with a dose of 80 kGy under nitrogen protection, and then treated in a hot air drying oven at 60℃ for 30 min to obtain water-absorbing and swellable fibers; the water-absorbing and swellable fibers are twisted to obtain functional yarns; the cross-linked sodium polyacrylate is obtained from Preparation Example 1.

[0093] Note: Since the improvement of this application lies in the water-absorbing and swelling fibers, and the twisting into functional yarns and then weaving them into fabrics is a conventional process, the specific processes of twisting and weaving are not described in detail in the embodiments. At the same time, the weaving process of the fabrics in this application includes, but is not limited to, weft knitting or warp knitting in machine weaving and knitting. Those skilled in the art can select the corresponding weaving equipment (such as circular knitting machine, warp knitting machine, shuttle loom, etc.) and process parameters (such as needle type, weaving density, warp and weft yarn ratio, etc.) according to the intended use of the fabric.

[0094] Comparative Example 1

[0095] This comparative example is the novel waterproof fabric prepared in Example 1 of the patent application with publication number CN108004777A.

[0096] Performance testing

[0097] (1) Air permeability: According to ASTM D773, the air permeability tester was used to test the air permeability at 129-249 Pa. The test results are recorded in Table 1.

[0098] (2) Water absorption test: The fabrics prepared in the examples and comparative examples were tested for water absorption rate in accordance with FZ / T52034-2014. The test results are recorded in Table 1.

[0099] (3) Waterproof test: The fabric after the water absorption test and the fabric prepared in the comparative example were subjected to hydrostatic pressure test according to GB / T4744-2013. The test results are recorded in Table 1.

[0100] (4) Moisture permeability test: The fabrics prepared in the examples and comparative examples were tested for moisture permeability in accordance with GB / T12704.2009A. The test results are recorded in Table 1.

[0101] (5) Antibacterial test: After washing the fabrics prepared in the examples and comparative examples 50 times, the antibacterial properties were tested according to the AATCC100-2019 standard, and a concentration of 9.6×10⁻⁶ was selected. 6 Staphylococcus aureus (AATCC6538P; Gram-positive) at CFU / mL was used as the test strain, and the test results are recorded in Table 1.

[0102] Table 1 Performance test data of Examples 1-13 and Comparative Example 1

[0103]

[0104] Combining Example 1 and Comparative Example 1, and referring to Table 1, it can be seen that, while possessing the core functions of water absorption and waterproofing, Example 1 achieves a significant improvement in breathability compared to Comparative Example 1, where the breathability of Comparative Example 1 is only 65.3 L / (m²).2 ·s), while Example 1, through a core-sheath structure design with PET fiber as the core layer and a specific ratio of absorbent polymer as the outer layer, improves air permeability to 82.5 L / (m). 2 The water absorption rate (23.6 g / g) and hydrostatic pressure after water absorption (1850 Pa) of Example 1 were increased by 84.4% and 39.4% respectively compared with Comparative Example 1 (12.8 g / g, 1320 Pa). This proves that the improvement in breathability is not at the expense of water absorption and waterproof performance. Instead, it is achieved through the layered structure of montmorillonite in the water-absorbing polymer and the porous network formed by sodium polyacrylate and polyvinyl alcohol. This ensures the waterproof effect of expanding and blocking gaps after water absorption, while also reserving gas circulation channels. This solves the problem that traditional waterproof fabrics cannot achieve both waterproof and breathable properties.

[0105] As can be seen from Examples 1 and 2 and Table 1, the addition of an appropriate amount of nanocellulose to the absorbent polymer in this application can improve the overall performance of the fabric. The one-dimensional fibrous structure of nanocellulose intertwines with the two-dimensional layered structure of montmorillonite to form a more regular porous network, which not only widens the gas flow channels, but also forms a dense hydrogen bond network with sodium polyacrylate and polyvinyl alcohol through the abundant hydroxyl groups on the surface, enhancing the polymer's adsorption capacity for water molecules, while strengthening the structural stability of the coating layer, thus slightly improving the waterproof effect after water absorption. Compared with Example 1 without the addition of nanocellulose, Example 2 further optimizes the water absorption performance and user comfort while maintaining the synergistic effect of the core functions of water absorption, waterproofing and breathability.

[0106] As can be seen from Examples 2 and 3 and Table 1, adding an appropriate amount of sodium alginate to the absorbent polymer in this application can further improve the overall performance of the fabric. The carboxyl groups of sodium alginate can form chelate interactions with potential metal ions in the system, and together with the hydrogen bond network of nanocellulose, further inhibit filler agglomeration, resulting in a more uniform porous structure in the coating layer. At the same time, the abundant hydrophilic groups of sodium alginate synergistically enhance water absorption capacity with sodium polyacrylate, and the dense hydrogen bond network it constructs also strengthens the structural stability of the coating layer after water absorption, allowing for simultaneous improvement in waterproofing and hydrostatic pressure. Compared to Example 2, which only contains nanocellulose, Example 3 achieves comprehensive synergistic optimization of water absorption, waterproofing, breathability, and antibacterial properties through the complementary functions of the two fillers, highlighting the significant advantages of the composite filler system compared to a single filler.

[0107] As can be seen from Examples 3 and 6-8 and Table 1, this application adds an appropriate amount of rare earth oxides to cross-linked sodium polyacrylate, which further optimizes the water absorption-waterproof balance and long-lasting antibacterial properties of the fabric. After modification by silane coupling agent (KH570), the rare earth oxides are chemically bonded and anchored in the sodium polyacrylate network, which not only enhances the water absorption capacity and structural stability of the polymer, but also significantly improves the antibacterial rate of the fabric due to their own antibacterial and antioxidant properties. When cerium oxide and lanthanum oxide are compounded in a 2:1 ratio, their ionic bonding ability and antibacterial activity form a synergistic effect, further optimizing the water absorption-waterproof balance and long-lasting antibacterial properties. Moreover, the hydrogen bond network and chelation effect of nanocellulose and sodium alginate are superimposed, achieving a comprehensive leap in performance without affecting breathability and moisture permeability, highlighting the synergistic system of "rare earth oxide modification + composite filler".

[0108] As can be seen from Examples 8 and 9 and Table 1, this application modifies rare earth oxides using a KH570 and perfluorooctyltriethoxysilane compound system. KH570 still ensures the chemical bonding between the rare earth oxides and the sodium polyacrylate network. The uniform hydrophobic microdomains introduced by perfluorooctyltriethoxysilane do not interfere with the adsorption of water molecules by hydrophilic groups, and can be superimposed with the layered barrier effect of montmorillonite, significantly enhancing the sealing effect of the gaps between yarns after water absorption. At the same time, the hydrophobic microdomains do not destroy the microporous channels formed by the interweaving of nanocellulose and montmorillonite, but instead optimize the gas flow efficiency, and synergize with the antibacterial activity of rare earth oxides to further enhance the long-lasting antibacterial properties. Compared with single KH570 modification, the compound silane coupling agent, based on rare earth compounding and composite filler, achieves improved water absorption, waterproofing, breathability and antibacterial properties.

[0109] As can be seen from Examples 3 and 12 and Table 1, this application pre-treats PET filaments, wherein plasma treatment introduces active groups such as hydroxyl and carboxyl groups on the PET surface, and subsequent PVA impregnation forms a uniform transition layer, which significantly enhances the interfacial bonding force between the PET core layer and the outer layer of water-absorbing polymer, avoiding local peeling or loose structure of the coating layer, and making the porous network formed by the water-absorbing polymer more complete and more uniformly distributed. This not only ensures rapid water molecule penetration and smooth gas flow, improving water absorption rate and breathability, but also makes the structure of the polymer layer that expands after water absorption more stable, with better gap sealing effect, thereby improving hydrostatic pressure. At the same time, it reduces the loss of functional components during washing, allowing the antibacterial rate to steadily increase. Without destroying the original core functional balance, it further optimizes the overall performance and usage stability of the fabric.

[0110] As can be seen from Examples 12 and 13 and Table 1, this application introduces a dopamine transition layer during PET pretreatment. The active groups introduced by plasma etching form covalent bonds with dopamine. The amino and catechol groups on the surface of polydopamine form strong hydrogen bonds with the hydroxyl groups of PVA and also have a synergistic effect with the hydroxyl groups of nanocellulose and the carboxyl groups of sodium alginate in the coating solution. This further enhances the interfacial bonding force compared to Example 12, thereby making the porous network of the coating layer more complete and uniform. This accelerates the penetration of water molecules and gas flow, strengthens the structural stability and gap sealing effect of the polymer layer after water absorption, and reduces the loss of functional components by washing. While maintaining the balance of water absorption, waterproofing and breathability, it achieves an improvement in comprehensive performance and usage stability.

[0111] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing a yarn with both water-absorbing and waterproof functions, characterized in that, A water-absorbing and swelling fiber is prepared by using PET fiber as the core layer and a water-absorbing polymer as the outer layer. The water-absorbing and swelling fiber is then twisted to produce a yarn with both water-absorbing and waterproof functions. The water-absorbing polymer includes the following raw materials in parts by weight: 70-80 parts of cross-linked sodium polyacrylate, 10-15 parts of sodium carboxymethyl cellulose, 5-10 parts of montmorillonite, and 3-5 parts of polyvinyl alcohol. The preparation method of the cross-linked sodium polyacrylate includes the following steps: (1) Mix silane coupling agent with ethanol and deionized water and adjust pH to 4-5, stir to form an active solution; add rare earth oxide nanoparticles to the ethanol solution and ultrasonically disperse to form a uniform suspension; add the active solution dropwise to the suspension, heat to 50-80℃, stir for 4-8h, centrifuge, wash and dry to obtain modified rare earth oxide nanoparticles. (2) Mix acrylic monomer with deionized water, add modified rare earth oxide nanoparticles, disperse by ultrasonication and adjust pH to 6-8, then add redox initiator solution and crosslinking agent, heat to 40-60℃ under inert gas atmosphere, stir reaction for 1-4h, gel is formed after reaction, wash and freeze dry to obtain crosslinked sodium polyacrylate composite material.

2. The method for preparing yarn with dual functions of water absorption and waterproofing according to claim 1, characterized in that, In step (1), the rare earth oxide nanoparticles are a mixture of cerium oxide and lanthanum oxide in a mass ratio of (1-3):

1.

3. The method for preparing yarn with dual functions of water absorption and waterproofing according to claim 1, characterized in that, In step (1), the silane coupling agent is a mixture of γ-methacryloxypropyltrimethoxysilane and perfluorooctyltriethoxysilane in a mass ratio of (7-9):(1-3).

4. The method for preparing yarn with dual functions of water absorption and waterproofing according to claim 1, characterized in that, The method for preparing the water-absorbing and swelling fiber includes the following steps: S1, add the raw materials of the water-absorbing polymer to deionized water in proportion to form a coating solution; S2, Immerse the PET filament in the coating solution and draw it through the coating solution to obtain coated fibers; S3 involves using electron beam radiation to crosslink and cure the coated fiber, followed by drying to obtain water-absorbing and swelling fibers.

5. The method for preparing yarn with dual functions of water absorption and waterproofing according to claim 4, characterized in that, The raw materials for the water-absorbing polymer also include 2-5 parts by weight of nanocellulose.

6. The method for preparing yarn with dual functions of water absorption and waterproofing according to claim 4, characterized in that, The raw materials for the water-absorbing polymer also include 1-3 parts by weight of sodium alginate.

7. The method for preparing yarn with dual functions of water absorption and waterproofing according to claim 4, characterized in that, In S2, the PET filaments are pretreated before being immersed in the coating solution. Specifically, the PET filaments are subjected to plasma etching treatment and then immersed in a 0.5wt% polyvinyl alcohol aqueous solution to obtain pretreated PET filaments.

8. The method for preparing yarn with dual functions of water absorption and waterproofing according to claim 4, characterized in that, In S2, the PET filaments are pretreated before being immersed in the coating solution. Specifically, after plasma etching, the PET filaments are first immersed in a 1wt% dopamine aqueous solution and then immersed in a 0.5wt% polyvinyl alcohol aqueous solution to obtain pretreated PET filaments.

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