High-water-absorption quick-drying sanitary material and preparation method thereof

Abstract

The invention provides a high-water-absorption quick-drying sanitary material and a preparation method thereof, and belongs to the technical field of water-absorption sanitary materials. Soybean protein isolate and tannic acid are compounded under the weakly alkaline condition, a protein-polyphenol three-dimensional network with hydrogen bonds, static electricity and hydrophobic effects as main effects is constructed in situ in emulsion droplets, the polyphenol-protein composite microgel with water absorption swelling capacity and mechanical strength is obtained, moisture can be bound after liquid absorption, and pressed back seepage is reduced; meanwhile, porous cellulose long fibers with communicated multistage pore channels are introduced, capillary diversion of the core body and diffusion of liquid in the plane and thickness direction are enhanced, framework support is provided in a wet state, and collapse and lump shrinkage of a fluff pulp / super absorbent resin system are slowed down; the two components and the super absorbent resin cooperate to form a'diversion skeleton-water locking infinitesimal-super absorbent unit 'liquid management structure, the liquid absorption amount is maintained, liquid migration and storage behaviors are optimized, and instantaneous absorption, distribution uniformity and pressed back-seepage prevention performance are considered.

Description

Technical Field

[0001] This invention belongs to the field of absorbent sanitary materials technology, and relates to a highly absorbent and quick-drying sanitary material and its preparation method. Background Technology

[0002] Disposable hygiene products, such as baby diapers and feminine hygiene pads, are indispensable personal care products in modern society, with their core function being the absorbent core. An ideal absorbent core needs to possess multiple properties simultaneously, including instant absorption, high water retention, pressure resistance and backflow prevention, dryness and breathability, and excellent core integrity. Currently, most mainstream absorbent cores on the market use a structure of physical blending wood pulp fibers with superabsorbent polymers. While this structure achieves a high theoretical absorbency with the help of superabsorbent polymers, it still has some shortcomings in practical applications.

[0003] First, when superabsorbent polymer (SAP) particles come into contact with liquid, they quickly swell on the surface to form a dense gel layer. This gel layer hinders further penetration and diffusion of the liquid, resulting in a large amount of SAP inside the absorbent core remaining unused. This not only increases the risk of side leakage but also reduces the overall absorption efficiency of the material. Second, the mixture of fibers and SAP particles is merely a simple physical mixture. After absorbing water, the rapid expansion of the SAP and the collapse of the fibers cause the core to lose its original fluffy structure, leading to breakage, clumping, and displacement during infant movement, severely impacting comfort and leak-proof performance. Furthermore, while traditional gel networks lock in liquid, they also block the escape channels for water vapor, resulting in a humid and hot internal environment that can easily cause skin problems such as diaper rash. Additionally, under external pressure such as sitting or lying down, this simple physical network is insufficient to firmly bind moisture, and some degree of backflow still occurs, failing to guarantee absolute dryness of the skin contact surface. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a highly absorbent and quick-drying sanitary material and its preparation method. This application involves compounding soy protein isolate with tannic acid under weakly alkaline conditions to construct an in-situ protein-polyphenol three-dimensional network within emulsion microdroplets, primarily based on hydrogen bonding, electrostatic interactions, and hydrophobicity. This yields a polyphenol-protein composite microgel possessing both water absorption and swelling capacity and mechanical strength, which can bind water after absorption and reduce pressure-induced backflow. Simultaneously, porous cellulose long fibers with interconnected multi-level channels are introduced to enhance capillary conduction in the core and liquid diffusion in both planar and thickness directions, providing skeletal support in a wet state and mitigating the collapse and shrinkage of the fluff pulp / superabsorbent resin system. These two components, together with the superabsorbent resin, constitute a "flow-guiding skeleton-water-locking micro-unit" liquid management structure, optimizing liquid migration and storage behavior while maintaining absorption capacity, thus balancing instantaneous absorption, uniform distribution, and pressure-induced backflow prevention performance.

[0005] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing a highly absorbent and quick-drying sanitary material, the method comprising: S1: Prepare an aqueous solution of soy protein isolate, adjust the pH with sodium hydroxide solution to obtain a protein solution, add tannic acid and adjust the pH again to obtain a reaction precursor solution; mix vegetable oil with Span 80 to obtain an oil phase, mix the reaction precursor solution with the oil phase, stir and shear to obtain an emulsion; stir the emulsion to obtain a reaction solution, add ethanol to break the emulsion, centrifuge, wash, and dry to obtain a polyphenol-protein composite microgel. S2: Disperse cellulose powder in an aqueous solution of N-methylmorpholine-N-oxide to obtain a mixture. Stir and heat the mixture until the cellulose is completely dissolved to obtain a spinning solution. Extrude the spinning solution through a spinneret into a deionized water coagulation bath to form hydrogel fibers. Wash the hydrogel fibers in flowing deionized water and then soak them in an aqueous ethanol solution to gradually replace the solvent and obtain alcohol gel fibers. Freeze the alcohol gel fibers and freeze-dry them to obtain porous cellulose long fibers. Cut the fibers to obtain porous cellulose fibers. S3: Wood pulp fluff fibers are opened using a fiber opening machine to obtain fluffy fluff pulp. Porous cellulose fibers, polyphenol-protein composite microgels, and superabsorbent resins are added and dry-blended in an air-flow mixer to obtain a composite absorbent core mixture. The composite absorbent core mixture is deposited onto a porous forming mesh belt through air-flow to form a fiber felt. The fiber felt is then compacted using pressure rollers to obtain a superabsorbent and quick-drying sanitary material.

[0006] As a preferred technical solution of the present invention, in step S1, the concentration of the sodium hydroxide solution is 0.1-0.5M, for example, it can be 0.10M, 0.14M, 0.18M, ​​0.22M, 0.26M, 0.30M, 0.34M, 0.38M, 0.42M, 0.46M or 0.50M, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0007] In some alternative embodiments, the aqueous soy protein isolate solution is adjusted to pH 7.5-8.5 using sodium hydroxide, for example, to 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4 or 8.5, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0008] In some optional embodiments, the protein solution has a mass fraction of 8-15 wt.%, for example, 8.0 wt.%, 8.7 wt.%, 9.4 wt.%, 10.1 wt.%, 10.8 wt.%, 11.5 wt.%, 12.2 wt.%, 12.9 wt.%, 13.6 wt.%, 14.3 wt.%, or 15.0 wt.%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0009] In some optional embodiments, the mass ratio of tannic acid to soy protein isolate is (1-4):20, for example, it can be 1.0:20, 1.3:20, 1.6:20, 1.9:20, 2.2:20, 2.5:20, 2.8:20, 3.1:20, 3.4:20, 3.7:20 or 4.0:20, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0010] In some alternative embodiments, the pH of the protein solution is adjusted again to 7.5-8.5 after the addition of tannic acid. For example, the pH can be adjusted again to 7.5, 7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.3, 8.4 or 8.5, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0011] In some alternative embodiments, the mass ratio of vegetable oil to Span 80 in the oil phase is 100:(1-5), for example, it can be 100:1.0, 100:1.4, 100:1.8, 100:2.2, 100:2.6, 100:3.0, 100:3.4, 100:3.8, 100:4.2, 100:4.6 or 100:5.0, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0012] In some optional embodiments, the volume ratio of the reaction precursor liquid to the oil phase is (1-3):10, for example, it can be 1.0:10, 1.2:10, 1.4:10, 1.6:10, 1.8:10, 2.0:10, 2.2:10, 2.4:10, 2.6:10, 2.8:10 or 3.0:10, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0013] In some optional embodiments, the temperature of the emulsion stirring reaction is 40-60°C, for example, 40°C, 42°C, 44°C, 46°C, 48°C, 50°C, 52°C, 54°C, 56°C, 58°C or 60°C, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0014] In some optional embodiments, the emulsion stirring reaction time is 1-4 hours, for example, 1.0 hours, 1.3 hours, 1.6 hours, 1.9 hours, 2.2 hours, 2.5 hours, 2.8 hours, 3.1 hours, 3.4 hours, 3.7 hours or 4.0 hours, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0015] In some optional embodiments, the volume ratio of ethanol to the reaction solution is (3-6):1, for example, it can be 3.0:1, 3.3:1, 3.6:1, 3.9:1, 4.2:1, 4.5:1, 4.8:1, 5.1:1, 5.4:1, 5.7:1 or 6.0:1, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0016] As a preferred technical solution of the present invention, in step S2, the concentration of the N-methylmorpholine-N-oxide aqueous solution is 75-85%, for example, it can be 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84% or 85%, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0017] In some alternative embodiments, the cellulose mass fraction in the mixture is 5-10 wt.%, for example, it can be 5.0 wt.%, 5.5 wt.%, 6.0 wt.%, 6.5 wt.%, 7.0 wt.%, 7.5 wt.%, 8.0 wt.%, 8.5 wt.%, 9.0 wt.%, 9.5 wt.%, or 10.0 wt.%, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0018] In some optional embodiments, the temperature for stirring and heating the mixture is 80-100°C, for example, 80°C, 82°C, 84°C, 86°C, 88°C, 90°C, 92°C, 94°C, 96°C, 98°C or 100°C, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0019] In some alternative embodiments, the diameter of the spinneret is 0.2-1.0 mm, for example, it can be 0.20 mm, 0.28 mm, 0.36 mm, 0.44 mm, 0.52 mm, 0.60 mm, 0.68 mm, 0.76 mm, 0.84 mm, 0.92 mm or 1.00 mm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0020] In some optional embodiments, the temperature of the deionized water coagulation bath is 10-40°C, for example, it can be 10°C, 13°C, 16°C, 19°C, 22°C, 25°C, 28°C, 31°C, 34°C, 37°C or 40°C, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0021] In some optional embodiments, the volume fraction of the ethanol-water solution is 30-100%, for example, it can be 30%, 37%, 44%, 51%, 58%, 65%, 72%, 79%, 86%, 93% or 100%, but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0022] In some optional embodiments, the freezing temperature of the alcohol gel fiber is -20 to -80°C, for example, -80°C, -74°C, -68°C, -62°C, -56°C, -50°C, -44°C, -38°C, -32°C, -26°C, or -20°C, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0023] In some optional embodiments, the freezing time of the alcohol gel fiber is 2-12 hours, for example, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours or 12 hours, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0024] In some alternative embodiments, the length of the porous cellulose fiber is 3-15 mm, for example, it can be 3.0 mm, 4.2 mm, 5.4 mm, 6.6 mm, 7.8 mm, 9.0 mm, 10.2 mm, 11.4 mm, 12.6 mm, 13.8 mm or 15.0 mm, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0025] As a preferred technical solution of the present invention, in step S3, the mass ratio of the porous cellulose fiber to the fluffy pulp is (5-35):100, for example, it can be 5:100, 8:100, 11:100, 14:100, 17:100, 20:100, 23:100, 26:100, 29:100, 32:100 or 35:100, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0026] In some optional embodiments, the mass ratio of the polyphenol-protein composite microgel to the fluffy pulp is (10-50):100, for example, it can be 10:100, 14:100, 18:100, 22:100, 26:100, 30:100, 34:100, 38:100, 42:100, 46:100 or 50:100, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0027] In some optional embodiments, the mass ratio of the superabsorbent resin to the fluffy pulp is (40-60):100, for example, it can be 40:100, 42:100, 44:100, 46:100, 48:100, 50:100, 52:100, 54:100, 56:100, 58:100 or 60:100, but is not limited to the listed values, other unlisted values ​​within this range are also applicable.

[0028] In some optional embodiments, the basis weight of the fiber felt is 300-800 g / m². 2 For example, it could be 300g / m 2 350g / m 2 400g / m 2 450g / m 2 500g / m 2 550g / m 2 600g / m 2 650g / m 2 700g / m 2 750g / m 2 Or 800g / m 2 However, this does not apply to all values ​​listed; other unlisted values ​​within the same range also apply.

[0029] In some alternative embodiments, the pressure for compacting the fiber felt is 0.1-0.5 MPa, for example, 0.10 MPa, 0.14 MPa, 0.18 MPa, 0.22 MPa, 0.26 MPa, 0.30 MPa, 0.34 MPa, 0.38 MPa, 0.42 MPa, 0.46 MPa or 0.50 MPa, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0030] Secondly, the present invention provides a highly absorbent and quick-drying sanitary material.

[0031] This application uses wood pulp fluff fibers as the main framework and introduces porous cellulose fibers and polyphenol-protein composite microgels. A basic fluffy network is constructed using fluff pulp, within which porous cellulose fibers form a porous flow-conducting framework. The polyphenol-protein composite microgels act as dispersed, dynamic water-locking micro-elements, working together with superabsorbent resin to hold a large volume of water. This clearly defined multi-scale structure improves upon problems such as liquid concentration, gel agglomeration, wet collapse, and pressure-induced backflow inherent in traditional fluff pulp / superabsorbent resin cores. While maintaining or approaching the liquid absorption capacity of traditional cores, it enhances instantaneous diffusion capacity and dryness under pressure.

[0032] This application introduces a polyphenol-protein composite microgel. Soy protein isolate dissolves under weakly alkaline conditions, opening some of its secondary and tertiary structures, making hydrophilic functional groups such as amino, carboxyl, and amide groups on the chain segments more easily exposed to the aqueous phase. Upon addition of tannic acid, some of its polyphenolic hydroxyl groups are deprotonated, allowing it to associate with protein molecules through hydrogen bonds, hydrophobic interactions, and certain π-π stacking. This protein / polyphenol solution is further dispersed into emulsion droplets. Under conditions of 40-60°C, tannic acid gradually oxidizes and aggregates, while protein segments entangle with each other through multi-point non-covalent interactions in the spatially confined environment of the droplets, ultimately forming a three-dimensional composite network within the droplet scale. Subsequent demulsification, washing, and drying steps remove the oil phase and emulsifier, leaving behind particles that are microgels containing the protein-polyphenol network. Because the network is mainly composed of hydrogen bonds, electrostatics, and hydrophobic associations, it has both a certain mechanical strength and retains a free volume that can absorb water and swell. This allows the microgel to quickly absorb and store a certain amount of liquid when absorbing water. At the same time, it can hinder the migration of internal water under external compression. Compared with uncrosslinked or weakly associated protein particles, it has a better inhibitory effect on backflow.

[0033] This application introduces porous cellulose fibers. Cellulose is dissolved in an aqueous solution of N-methylmorpholine-N-oxide to form a uniform spinning solution. After wet spinning and extrusion into a water coagulation bath, the dissolved cellulose molecular chains undergo phase separation and regeneration in a non-solvent environment, forming regenerated cellulose hydrogel fibers. Residual solvent is subsequently removed by washing with flowing water, followed by ethanol solvent replacement and low-temperature freezing treatment. This causes the original solvent phase inside the fiber to be separated and templated into hierarchical pores by ice crystals and solvent phases. During freeze-drying, the ice crystals sublimate, leaving behind a network of interconnected pores, thus obtaining porous cellulose long fibers with high porosity. Compared with traditional solid regenerated fibers, this type of porous fiber has more significant capillary channels and specific surface area in both the axial and radial directions. When distributed in the fluff pulp network, it can enhance the local capillary liquid absorption capacity and the liquid migration rate in the planar and thickness directions, helping to rapidly transfer liquid from the infiltration area to the core and edge areas, alleviating the accumulation of liquid in a short period of time in a localized area. Meanwhile, the regenerated skeleton of porous fibers provides a certain spatial support for the core, which helps to slow down the overall collapse and local shrinkage of the fluff pulp / superabsorbent resin system when liquid absorption and swelling occur, and maintains the connectivity and air permeability of the internal pore structure of the core.

[0034] In the composite absorbent core, wood pulp fluff fibers constitute the main volumetric framework and basic liquid-absorbing matrix, while porous cellulose fibers are uniformly dispersed within the fluff pulp network, forming a porous flow-conducting framework that runs through the thickness and in-plane directions. When liquid enters the core from the surface, the fluff fibers and porous fibers initially participate in absorption together. The internal channels of the porous fibers and the capillary gaps between the fibers provide a lower-resistance flow path, guiding the liquid to quickly leave the surface and diffuse within the core, shortening the surface wetting time and improving the uniformity of liquid distribution in the planar and thickness directions. Polyphenol-protein composite microgels are dispersed in particulate form between the flow-conducting framework and the fluff pulp, acting as dispersed water-locking micro-elements. When liquid passes through or remains around them, the microgels can quickly absorb water and swell, relying on their internal multi-point non-covalent cross-linked network to bind the absorbed water. Under subsequent external compression (such as sitting, lying down, or turning over), the proportion of free water that can be squeezed out per unit volume is reduced, thus helping to reduce surface backflow.

[0035] Meanwhile, after the introduction of superabsorbent polymer (SAP) into the core, the porous cellulose fibers and polyphenol-protein microgels also play a synergistic role in the transport and buffering of liquid to the SAP. On the one hand, the porous cellulose fibers facilitate the more complete delivery of liquid to the vicinity of the SAP particles, allowing the SAP to participate in water absorption over a larger volume area, reducing the instantaneous over-expansion and gel barrier phenomenon caused by liquid concentrating in local SAP regions. On the other hand, before the SAP is fully swollen, the polyphenol-protein microgels can undertake part of the initial liquid absorption and pressure-bearing water-locking functions. Under pressure, they share the local load with the fluff pulp and porous cellulose fibers, reducing the structural instability and backflow risk caused by local softening of the SAP. Through this multi-level synergy of "flow-guiding skeleton - water-locking micro-element - super absorbent unit", a flow-guiding and water-locking module with adjustable structure is introduced on the basis of the traditional fluff pulp / super absorbent resin system. The migration, storage and release behavior of liquid in the core is optimized from the two levels of micro-network structure and macro-fluid path, so that the core can take into account instantaneous absorption rate, liquid distribution uniformity, wet structure stability and pressure-resistant backflow performance.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows: This application describes a polyphenol-protein composite microgel prepared by combining soy protein isolate with tannic acid under weakly alkaline conditions and constructing a protein-polyphenol three-dimensional network in situ within emulsion microdroplets. This microgel exhibits both good water absorption and swelling capacity and certain mechanical strength. After absorbing liquid, it can quickly store water and inhibit internal water migration under pressure, thereby effectively reducing liquid backflow.

[0037] This application introduces porous cellulose long fibers with interconnected hierarchical channels. Compared to traditional solid regenerated fibers, these porous fibers have more developed capillary channels and a higher specific surface area. When incorporated into fluff pulp, they enhance capillary liquid absorption and the migration speed of liquid in both planar and thickness directions, promoting rapid liquid transfer from the infiltration zone to the interior and edges. Simultaneously, the porous fiber skeleton provides spatial support for the fluff pulp / superabsorbent resin system during liquid absorption and swelling, helping to mitigate wet collapse and localized shrinkage, and maintaining the connectivity and permeability of the core's pore structure.

[0038] This application constructs a synergistic system of "flow-guiding framework - water-locking micro-element - highly absorbent unit" by introducing porous cellulose fibers and polyphenol-protein composite microgels. The porous cellulose fibers form interconnected flow channels in the fluff pulp, promoting rapid liquid removal from the surface and uniform diffusion within the core. The polyphenol-protein composite microgels act as dispersing water-locking units, binding water through their internal network after absorption and reducing the extrusion of free water under pressure. The porous fibers facilitate more uniform liquid transport around the resin, reducing local gelation barriers, while the polyphenol-protein composite microgels share the initial liquid absorption and pressure-resistant water locking before the resin is fully swollen. Thus, liquid migration and storage behavior are synergistically optimized from both flow-guiding and water-locking perspectives, balancing instantaneous absorption, uniform distribution, and pressure-resistant backflow prevention performance. Detailed Implementation

[0039] The technical solution of the present invention will be described in detail below with reference to specific embodiments. The embodiments described herein are specific implementations of the present invention and are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be construed as limiting the implementation of the present invention or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the content disclosed in the claims and the specification of this application. These technical solutions include technical solutions that employ any obvious substitutions and modifications made to the embodiments described herein.

[0040] The chemical reagents used in the embodiments and comparative examples of this invention are all commercially available products and have not undergone further purification or processing.

[0041] Example 1 This embodiment provides a highly absorbent and quick-drying sanitary material and its preparation method. The preparation method of the highly absorbent and quick-drying sanitary material specifically includes the following steps: S1: Prepare an aqueous solution of soy protein isolate. Adjust the pH to 8.2 using a 0.4M sodium hydroxide solution to obtain a protein solution with a mass fraction of 12 wt.%. Add tannic acid and adjust the pH to 8.2 again to obtain a reaction precursor solution, wherein the mass ratio of tannic acid to soy protein isolate is 3:20. Mix vegetable oil and Span 80 at a mass ratio of 100:4 to obtain an oil phase. Mix the reaction precursor solution and the oil phase at a volume ratio of 2.5:10, and stir and shear to obtain an emulsion. Stir the emulsion at 55℃ for 3.5 h to obtain a reaction solution. Add ethanol to break the emulsion, wherein the volume ratio of ethanol to the reaction solution is 5:1. Centrifuge, wash, and dry to obtain a polyphenol-protein composite microgel. S2: Cellulose powder is dispersed in an 82% N-methylmorpholine-N-oxide aqueous solution to obtain a mixture, wherein the mass fraction of cellulose in the mixture is 8 wt.%. The mixture is stirred and heated at 95°C until the cellulose is completely dissolved to obtain a spinning solution. The spinning solution is extruded through a 0.8 mm diameter spinneret into a deionized water coagulation bath at 35°C to form hydrogel fibers. The hydrogel fibers are washed in flowing deionized water and then immersed in an 80% ethanol aqueous solution to gradually replace the solvent and obtain alcohol gel fibers. The alcohol gel fibers are frozen at -60°C for 10 h and then freeze-dried to obtain porous cellulose long fibers. These fibers are cut to obtain porous cellulose fibers with a length of 12 mm. S3: Wood pulp fluff fibers are opened using a fiber opening machine to obtain fluffy fluff pulp. Porous cellulose fibers, polyphenol-protein composite microgels, and superabsorbent resins are added, and the mixture is dry-blended in an air-jet mixer to obtain a composite absorbent core mixture. The mass ratio of porous cellulose fibers to fluffy fluff pulp is 25:100, the mass ratio of polyphenol-protein composite microgels to fluffy fluff pulp is 40:100, and the mass ratio of superabsorbent resins to fluffy fluff pulp is 55:100. The composite absorbent core mixture is then deposited onto a porous forming mesh belt using an air-jet fabrication process to form a composite core mixture with a basis weight of 700 g / m³. 2 The fiber felt is compacted under a pressure of 0.4 MPa using a pressure roller to obtain a highly absorbent and quick-drying sanitary material.

[0042] Example 2 This embodiment provides a highly absorbent and quick-drying sanitary material and its preparation method. The preparation method of the highly absorbent and quick-drying sanitary material specifically includes the following steps: S1: Prepare an aqueous solution of soy protein isolate. Adjust the pH to 7.5 using a 0.1M sodium hydroxide solution to obtain a protein solution with a mass fraction of 8 wt.%. Add tannic acid and adjust the pH to 7.5 again to obtain a reaction precursor solution, wherein the mass ratio of tannic acid to soy protein isolate is 1:20. Mix vegetable oil and Span 80 at a mass ratio of 100:1 to obtain an oil phase. Mix the reaction precursor solution and the oil phase at a volume ratio of 1:10, and stir and shear to obtain an emulsion. Stir the emulsion at 40℃ for 1 h to obtain a reaction solution. Add ethanol to break the emulsion, wherein the volume ratio of ethanol to the reaction solution is 3:1. Centrifuge, wash, and dry to obtain a polyphenol-protein composite microgel. S2: Cellulose powder is dispersed in a 75% N-methylmorpholine-N-oxide aqueous solution to obtain a mixture, wherein the mass fraction of cellulose in the mixture is 5 wt.%. The mixture is stirred and heated at 80°C until the cellulose is completely dissolved to obtain a spinning solution. The spinning solution is extruded through a 0.2 mm diameter spinneret into a deionized water coagulation bath at 10°C to form hydrogel fibers. The hydrogel fibers are washed in flowing deionized water and then immersed in a 30% volume fraction ethanol aqueous solution to gradually replace the solvent and obtain alcohol gel fibers. The alcohol gel fibers are frozen at -20°C for 2 h and then freeze-dried to obtain porous cellulose long fibers. These fibers are cut to obtain porous cellulose fibers with a length of 3 mm. S3: Wood pulp fluff fibers are opened using a fiber opening machine to obtain fluffy fluff pulp. Porous cellulose fibers, polyphenol-protein composite microgels, and superabsorbent resins are added, and the mixture is dry-blended in an air-jet mixer to obtain a composite absorbent core mixture. The mass ratio of porous cellulose fibers to fluffy fluff pulp is 5:100, the mass ratio of polyphenol-protein composite microgels to fluffy fluff pulp is 10:100, and the mass ratio of superabsorbent resins to fluffy fluff pulp is 40:100. The composite absorbent core mixture is then deposited onto a porous forming mesh belt using an air-jet fabrication process to form a composite core mixture with a basis weight of 300 g / m³. 2 The fiber felt is compacted under a pressure of 0.1 MPa using a pressure roller to obtain a highly absorbent and quick-drying sanitary material.

[0043] Example 3 This embodiment provides a highly absorbent and quick-drying sanitary material and its preparation method. The preparation method of the highly absorbent and quick-drying sanitary material specifically includes the following steps: S1: Prepare an aqueous solution of soy protein isolate. Adjust the pH to 7.8 using a 0.2M sodium hydroxide solution to obtain a protein solution with a mass fraction of 10 wt.%. Add tannic acid and adjust the pH to 7.8 again to obtain a reaction precursor solution, wherein the mass ratio of tannic acid to soy protein isolate is 2:20. Mix vegetable oil and Span 80 at a mass ratio of 100:2 to obtain an oil phase. Mix the reaction precursor solution and the oil phase at a volume ratio of 1.5:10, and stir and shear to obtain an emulsion. Stir the emulsion at 45℃ for 2 hours to obtain a reaction solution. Add ethanol to break the emulsion, wherein the volume ratio of ethanol to the reaction solution is 4:1. Centrifuge, wash, and dry to obtain a polyphenol-protein composite microgel. S2: Cellulose powder is dispersed in a 78% N-methylmorpholine-N-oxide aqueous solution to obtain a mixture, wherein the mass fraction of cellulose in the mixture is 6 wt.%. The mixture is stirred and heated at 85°C until the cellulose is completely dissolved to obtain a spinning solution. The spinning solution is extruded through a 0.5 mm diameter spinneret into a deionized water coagulation bath at 20°C to form hydrogel fibers. The hydrogel fibers are washed in flowing deionized water and then immersed in a 50% volume fraction ethanol aqueous solution to gradually replace the solvent and obtain alcohol gel fibers. The alcohol gel fibers are frozen at -40°C for 5 h and then freeze-dried to obtain porous cellulose long fibers. These fibers are cut to obtain porous cellulose fibers with a length of 8 mm. S3: Wood pulp fluff fibers are opened using a fiber opening machine to obtain fluffy fluff pulp. Porous cellulose fibers, polyphenol-protein composite microgels, and superabsorbent resins are added, and the mixture is dry-blended in an air-jet mixer to obtain a composite absorbent core mixture. The mass ratio of porous cellulose fibers to fluffy fluff pulp is 10:100, the mass ratio of polyphenol-protein composite microgels to fluffy fluff pulp is 20:100, and the mass ratio of superabsorbent resins to fluffy fluff pulp is 45:100. The composite absorbent core mixture is then deposited onto a porous forming mesh belt using an air-jet fabrication process to form a composite core mixture with a basis weight of 500 g / m³. 2 The fiber felt is compacted under a pressure of 0.2 MPa using a pressure roller to obtain a highly absorbent and quick-drying sanitary material.

[0044] Example 4 This embodiment provides a highly absorbent and quick-drying sanitary material and its preparation method. The preparation method of the highly absorbent and quick-drying sanitary material specifically includes the following steps: S1: Prepare an aqueous solution of soy protein isolate. Adjust the pH to 8.5 using a 0.5M sodium hydroxide solution to obtain a protein solution with a mass fraction of 15 wt.%. Add tannic acid and adjust the pH to 8.5 again to obtain a reaction precursor solution, wherein the mass ratio of tannic acid to soy protein isolate is 4:20. Mix vegetable oil and Span 80 at a mass ratio of 100:5 to obtain an oil phase. Mix the reaction precursor solution and the oil phase at a volume ratio of 3:10, and stir and shear to obtain an emulsion. Stir the emulsion at 60℃ for 4 hours to obtain a reaction solution. Add ethanol to break the emulsion, wherein the volume ratio of ethanol to the reaction solution is 6:1. Centrifuge, wash, and dry to obtain a polyphenol-protein composite microgel. S2: Cellulose powder is dispersed in an 85% N-methylmorpholine-N-oxide aqueous solution to obtain a mixture, wherein the mass fraction of cellulose in the mixture is 10 wt.%. The mixture is stirred and heated at 100°C until the cellulose is completely dissolved to obtain a spinning solution. The spinning solution is extruded through a 1.0 mm diameter spinneret into a deionized water coagulation bath at 40°C to form hydrogel fibers. The hydrogel fibers are washed in flowing deionized water and then immersed in a 100% volume fraction ethanol aqueous solution to gradually replace the solvent and obtain alcohol gel fibers. The alcohol gel fibers are frozen at -80°C for 12 h and then freeze-dried to obtain porous cellulose long fibers. These fibers are cut to obtain porous cellulose fibers with a length of 15 mm. S3: Wood pulp fluff fibers are opened using a fiber opening machine to obtain fluffy fluff pulp. Porous cellulose fibers, polyphenol-protein composite microgels, and superabsorbent resins are added, and the mixture is dry-blended in an air-jet mixer to obtain a composite absorbent core mixture. The mass ratio of porous cellulose fibers to fluffy fluff pulp is 35:100, the mass ratio of polyphenol-protein composite microgels to fluffy fluff pulp is 50:100, and the mass ratio of superabsorbent resins to fluffy fluff pulp is 60:100. The composite absorbent core mixture is then deposited onto a porous forming mesh belt using an air-jet fabrication process to form a composite core mixture with a basis weight of 800 g / m³. 2 The fiber felt is compacted under a pressure of 0.5 MPa using a pressure roller to obtain a highly absorbent and quick-drying sanitary material.

[0045] Comparative Example 1 This comparative example provides a highly absorbent and quick-drying sanitary material. The difference between this example and Example 1 is that porous cellulose fibers and polyphenol-protein composite microgels are not added. Other operating steps and process parameters are exactly the same as in Example 1.

[0046] Comparative Example 2 This comparative example provides a highly absorbent and quick-drying sanitary material. The difference between this example and Example 1 is that porous cellulose fibers are not added, while the other operating steps and process parameters are exactly the same as in Example 1.

[0047] Comparative Example 3 This comparative example provides a highly absorbent and quick-drying sanitary material. The difference between this example and Example 1 is that no polyphenol-protein composite microgel is added. All other operating steps and process parameters are exactly the same as in Example 1.

[0048] Comparative Example 4 This comparative example provides a highly absorbent and quick-drying sanitary material. The difference from Example 1 is that in S2, the hydrogel fibers are washed in flowing deionized water and then directly dried and cut to obtain solid cellulose fibers. Other operation steps and process parameters are exactly the same as in Example 1.

[0049] The performance of the superabsorbent and quick-drying sanitary materials of Examples 1-4 and Comparative Examples 1-4 was tested, and the specific process is as follows: Total water absorption rate test: After placing samples with the same cut size and weight in a constant temperature and humidity chamber for equilibration for 24 hours, remove them and weigh their initial mass m0. Then, vertically immerse the samples in a 0.9 wt.% sodium chloride simulated urine solution and allow them to freely expand and absorb water for 30 minutes without external load. After removal, allow the samples to drip naturally on a standard sieve for 2 minutes until no more obvious droplets fall from the sample. Immediately weigh the wet mass m1 and calculate the total water absorption rate.

[0050] Total water absorption rate = (m1 - m0) / m0 × 100%; Absorption rate test: Samples of the same cut size and weight were placed on a flat porous support plate. Using a titration device, 50 mL of 0.9 wt.% sodium chloride simulated urine was vertically added dropwise from the center of the sample surface in a single injection. The time from the start of injection until no visible free liquid was visible on the sample surface was recorded.

[0051] Diffusion uniformity test: Samples of the same cut size were placed on a transparent plexiglass platform. A 0.9 wt.% sodium chloride solution containing an appropriate amount of water-soluble dye was used as the tracer solution. 20 mL of the solution was injected at once from the center of the sample surface and allowed to stand for 10 min. The maximum wetting radius was recorded.

[0052] Pressure-induced backflow test: After injecting 50 mL of 0.9 wt.% sodium chloride solution into the center of a sample of the same cut size, and allowing it to stand for 5 min, place three layers of quantitative filter paper (the area of ​​the filter paper is slightly larger than the test area of ​​the sample) on the sample surface. Apply a uniform pressure of 5 kPa to the filter paper for 1 min using a loading device. Immediately after depressurization, remove the filter paper and weigh its weight gain.

[0053] Wet pressure collapse rate: Under constant temperature and humidity conditions (25℃, relative humidity 50%), the core sample was placed in a 0.9wt.% sodium chloride simulated urine solution to freely absorb 50mL of water. After removal, the sample was allowed to drip naturally onto a standard sieve for 2 minutes to remove free liquid from the surface. The sample was then placed flat on a thickness testing platform, and its initial thickness H0 was measured. Subsequently, a certain surface pressure was applied and held for 30 seconds, and the wet pressure-bearing thickness H1 at this point was measured. The retention rate was calculated.

[0054] The test results are shown in Table 1.

[0055] Table 1: Performance test results of the superabsorbent and quick-drying sanitary materials in Examples 1-4 and Comparative Examples 1-4 As shown in Table 1, the test results of Example 1 and Comparative Example 1 reveal that without the addition of porous cellulose fibers and polyphenol-protein composite microgels, the core is composed only of fluff pulp and superabsorbent resin, lacking the synergistic structure of "flow-guiding framework-water-locking micro-elements". After liquid enters, it mainly relies on the fluff and local superabsorbent resin areas for infiltration and absorption. The migration paths in the in-plane and thickness directions are limited, resulting in a reduced absorption rate, a smaller wetting range, and a greater tendency for liquid to accumulate near the injection area. Under pressure, free water is mainly absorbed by the fluff gaps and locally gelled superabsorbent resin, and is easily squeezed back to the surface, increasing the amount of backflow. At the same time, the core lacks a stable spatial support framework, making it more prone to compression and collapse under load after water absorption, thus reducing the wet thickness retention rate.

[0056] As shown in Table 1, the test results of Example 1 and Comparative Example 2 reveal that without the addition of porous cellulose fibers and with the absence of a flow-conducting framework, the main migration path of the liquid in the core still relies on the villous structure and the gaps between local particles. The discontinuous capillary channels result in insufficient overall flow capacity, weakened liquid withdrawal from the surface and diffusion rate on the plane, prolonged absorption time, and reduced wetting radius. Although the polyphenol-protein composite microgel can provide some water-locking and pressure-resistant water retention in local areas, partially preserving its pressure-induced reabsorption performance, the insufficient transport and dispersion efficiency of the liquid on a macroscopic scale still results in noticeable localized high-water-content areas, limiting the support capacity of the wet framework.

[0057] As shown in Table 1, the test results of Example 1 and Comparative Example 3 indicate that even without the addition of polyphenol-protein composite microgel, porous cellulose fibers can still construct multi-level capillary channels in the fluff pulp, allowing liquid to migrate more quickly from the surface to the interior and periphery. Therefore, the absorption rate and wetting radius remain relatively stable, and the conductivity and diffusion properties are essentially maintained. However, the lack of water-locking micro-elements capable of binding water at the microscale means that the absorbed free water is mainly concentrated in the superabsorbent resin gel and fiber pores, making it easier to squeeze out under pressure, leading to increased surface backflow. Simultaneously, under high water content, localized stress concentration reduces the pressure-bearing capacity of the wet structure.

[0058] As shown in Table 1, the test results of Example 1 and Comparative Example 4 reveal that in S2, the hydrogel fibers were simply washed in flowing deionized water, dried, and cut to obtain solid cellulose fibers. This process lacked the multi-level interconnected pore structure formed through solvent replacement and freeze-drying. While solid cellulose fibers possess some hydrophilicity and skeletal function, they have almost no effective open pores. Capillary conduction mainly relies on the gaps between fibers, and their conduction and diffusion capabilities are significantly weaker than those of the porous cellulose fiber-based conduction skeleton, resulting in a decreased absorption rate and wetting radius. Furthermore, the system still retains the polyphenol-protein composite microgel, thus providing some water-locking effect under pressure. However, due to insufficient conduction efficiency and spatial support, both the wet pressure collapse rate and pressure-induced re-permeability deteriorate.

[0059] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a high water-absorbing and quick-drying sanitary material, characterized by, The preparation method comprises: S1: configuring a soybean protein isolate aqueous solution, adjusting the pH to obtain a protein solution by using a sodium hydroxide solution, adding tannic acid and adjusting the pH again to obtain a reaction precursor solution; mixing vegetable oil with Span 80 to obtain an oil phase, mixing the reaction precursor solution with the oil phase, and stirring and shearing to obtain an emulsion; stirring and reacting the emulsion to obtain a reaction solution, adding ethanol for demulsification and centrifugation, washing, and drying to obtain polyphenol-protein composite microgels; S2: dispersing cellulose powder in an N-methylmorpholine-N-oxide aqueous solution to obtain a mixture, stirring and heating the mixture to cellulose completely dissolving to obtain a spinning dope; extruding the spinning dope through a spinneret into a deionized water coagulation bath to form a hydrogel fiber, washing the hydrogel fiber in flowing deionized water, and then immersing the hydrogel fiber in an ethanol aqueous solution to gradually perform solvent replacement to obtain an alcogel fiber, freezing the alcogel fiber, and freeze-drying the alcogel fiber to obtain a porous cellulose long fiber, and cutting the porous cellulose long fiber to obtain a porous cellulose fiber; S3: opening the wood pulp fluff fiber by using a fiber opening machine to obtain fluffy pulp fluff, adding the porous cellulose fiber, the polyphenol-protein composite microgel, and a superabsorbent resin, and performing dry blending in an air flow mixer to obtain a composite absorbent core mixture, depositing the composite absorbent core mixture on a porous forming mesh belt by air flow laying to form a fiber mat, and compacting the fiber mat by using a press roller to obtain a superabsorbent quick-drying sanitary material.

2. The method for preparing a highly absorbent and quick-drying sanitary material according to claim 1, characterized in that, In S1: The mass fraction of the protein solution is 8-15 wt.%; The mass ratio of the tannic acid to the soybean protein isolate is (1-4):

20.

3. The method for preparing a highly absorbent and quick-drying sanitary material according to claim 1, characterized in that, In S1: The mass ratio of the vegetable oil to Span 80 in the oil phase is 100:(1-5).

4. The method for preparing a highly absorbent and quick-drying sanitary material according to claim 1, characterized in that, In S1: The volume ratio of the reaction precursor solution to the oil phase is (1-3):

10.

5. The method for preparing a highly absorbent and quick-drying sanitary material according to claim 1, characterized in that, In S1: The volume ratio of the ethanol to the reaction solution is (3-6):

1.

6. The method for preparing a highly absorbent and quick-drying sanitary material according to claim 1, characterized in that, In S2: The concentration of the N-methylmorpholine-N-oxide aqueous solution is 75-85%; The mass fraction of the cellulose in the mixture is 5-10 wt.%.

7. The method for preparing a highly absorbent and quick-drying sanitary material according to claim 1, characterized in that, In S2: The temperature for stirring and heating the mixture is 80-100℃; The temperature of the deionized water coagulation bath is 10-40℃; The volume fraction of the ethanol aqueous solution is 30-100%.

8. The method for preparing a highly absorbent and quick-drying sanitary material according to claim 1, characterized in that, In S4: The mass ratio of the porous cellulose fiber to the fluffy pulp fluff is (5-35):100; The mass ratio of the polyphenol-protein composite microgel to the fluffy pulp fluff is (10-50):

100.

9. The method for preparing a highly absorbent and quick-drying sanitary material according to claim 1, characterized in that, In S4: The mass ratio of the superabsorbent resin to the fluffy pulp fluff is (40-60):100; The grammage of the fiber mat is 300-800 g / m²; The pressure for compacting the fiber mat is 0.1-0.5 MPa.

10. A superabsorbent quick-drying sanitary material prepared by the preparation method according to any one of claims 1-9.

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