CN119061583B

CN119061583B - A high-strength hydrogel/microfiber nonwoven composite material, its preparation method and application

Info

Publication number: CN119061583B
Application number: CN202411187501.5A
Authority: CN
Inventors: 朵永超; 钱晓明; 宋兵; 符浩
Original assignee: Tianjin Polytechnic University
Current assignee: Tiangong University
Priority date: 2024-08-28
Filing date: 2024-08-28
Publication date: 2025-11-18
Anticipated expiration: 2044-08-28
Also published as: CN119061583A

Abstract

The invention belongs to the technical field of hydrogel and superfine fiber, and provides a high-strength hydrogel/superfine fiber non-woven composite material, and a preparation method and application thereof. The method comprises the steps of independently melting a first polymer and a second polymer, carrying out composite spinning on the obtained melt to obtain water-soluble polyvinyl alcohol bicomponent fibers, wherein the first polymer is thermoplastic polyvinyl alcohol, carrying out drafting, carding, reinforcing and water-soluble fiber-opening treatment on the water-soluble polyvinyl alcohol bicomponent fibers to obtain a solution containing a non-woven material, mixing the solution containing the non-woven material with an additive solution, and carrying out crosslinking and freezing treatment in sequence to obtain the high-strength hydrogel/superfine fiber non-woven composite material. The composite material takes the superfine fibers as a framework, realizes the mutual cladding between the hydrogel and the superfine fibers, has ultrahigh mechanical strength, and has good application prospect in the fields of facial masks, wound dressings, cooling patches and the like.

Description

High-strength hydrogel/superfine fiber non-woven composite material and preparation method and application thereof

Technical Field

The invention relates to the technical field of hydrogel and superfine fibers, in particular to a high-strength hydrogel/superfine fiber non-woven composite material, and a preparation method and application thereof.

Background

The melt spinning bicomponent superfine fiber is paid attention to because of the advantages of excellent mechanical property, finer fiber morphology, large-scale preparation and the like, and the nonwoven material prepared by the fiber has good application prospect in the fields of superfine fiber synthetic leather, filter materials, wiping materials and the like. However, there is little research on the use of bicomponent microfibers in the hydrogel field. Due to the excellent water-solubility of the polyvinyl alcohol bicomponent fiber, the fiber can be completely cracked under the environment-friendly and low-energy consumption conditions, the problems that the bicomponent fiber is difficult to split, easy to pollute, high in energy consumption and the like are solved, and meanwhile, due to the swelling property of the polyvinyl alcohol, the fiber has a certain research value in the field of hydrogels.

Polyvinyl alcohol hydrogel is a water-swellable crosslinked polymer network, and has become a material with good prospects in various fields such as biomedical engineering, flexible sensors, environmental research and the like due to the soft and water-containing properties. However, conventional polyvinyl alcohol hydrogels are often very fragile and very fragile due to problems of loose cross-links, low solids content, homogeneous structure, etc., and such poor mechanical properties greatly limit their application range.

In order to solve the problems, a patent CN115895155A discloses a preparation method of a poly (p-dioxanone)/poly (vinyl alcohol) hydrogel, wherein poly (p-dioxanone)/poly (vinyl alcohol) hydrogel is used as a reinforcing material, and is dispersed in the poly (vinyl alcohol) hydrogel which is used as a main material to form a hydrogel with a network interpenetrating structure, so that the mechanical property of the poly (vinyl alcohol) hydrogel is improved, a patent CN117736475A proposes a preparation method of a high-toughness wear-resistant hydrogel, which comprises freezing a poly (vinyl alcohol)/chitosan aqueous solution, then thawing the poly (chitosan) aqueous solution to obtain the poly (vinyl alcohol)/chitosan hydrogel, then sequentially salting out, annealing and water dialysis balancing the poly (vinyl alcohol)/chitosan hydrogel to obtain the high-toughness wear-resistant hydrogel, and a patent CN116903977A discloses a poly (vinyl alcohol) fabric hydrogel, wherein a vinylon fabric is soaked in a sulfuric acid aqueous solution to reduce the vinylon into poly (vinyl alcohol), and then the poly (vinyl alcohol) fabric is washed by deionized water, fully soaked in a cross-linking agent, and then placed between two layers of polypropylene films, and then a physical freeze thawing mode is adopted to prepare the poly (vinyl alcohol fabric) gel. However, the polyvinyl alcohol hydrogel produced by the preparation method still has the problems of poor mechanical properties, complex preparation process, need of introducing other polymers and the like, and is difficult to meet the actual application demands. Therefore, how to prepare a polyvinyl alcohol hydrogel with excellent mechanical properties, higher water content and with superfine fiber as a framework has become a problem to be solved in the field of hydrogels.

Disclosure of Invention

The invention aims to overcome the problems in the prior art and provides a high-strength hydrogel/superfine fiber non-woven composite material, and a preparation method and application thereof.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a preparation method of a high-strength hydrogel/superfine fiber non-woven composite material, which comprises the following steps:

(1) Independently melting a first polymer and a second polymer to obtain a melt of the first polymer and a melt of the second polymer, and carrying out composite spinning on the melt of the first polymer and the melt of the second polymer to obtain water-soluble polyvinyl alcohol bicomponent fibers, wherein the first polymer is thermoplastic polyvinyl alcohol;

(2) Drawing the water-soluble polyvinyl alcohol bicomponent fiber to obtain a short fiber;

(3) Carding the short fibers to obtain a polyvinyl alcohol bicomponent fiber web;

(4) Reinforcing the polyvinyl alcohol bicomponent fiber web to obtain a water-soluble polyvinyl alcohol bicomponent carding-needling nonwoven material;

(5) Carrying out water-soluble fiber dissolving treatment on the water-soluble polyvinyl alcohol bi-component carding-needling non-woven material to obtain a solution containing the non-woven material;

(6) And mixing the solution containing the non-woven material with the additive solution, and sequentially performing crosslinking and freezing treatment to obtain the high-strength hydrogel/superfine fiber non-woven composite material.

Preferably, the weight average molecular weight of the thermoplastic polyvinyl alcohol in the step (1) is 6600-7200, the alcoholysis degree of the thermoplastic polyvinyl alcohol is 88-99%, the polymerization degree of the thermoplastic polyvinyl alcohol is 300-700, and the melt flow index of the thermoplastic polyvinyl alcohol is 31-52 g/10min;

The second polymer comprises a polyester, a polyamide, a poly (adipic acid)/poly (butylene terephthalate), or a poly (lactic acid);

the mass ratio of the first polymer to the second polymer is 1-5:5-9.

Preferably, the die temperature of the composite spinning in the step (1) is 230-250 ℃, and the speed of the composite spinning is 500-4000 m/min.

Preferably, the drawing mode in the step (2) is dry heat drawing, the drawing temperature is 95-105 ℃, and the drawing multiplying power is 3.5-5.5 times.

Preferably, the reinforcement mode in the step (4) is needling, the needling density is 500-1500 needling/cm ², the needling depth is 4-8 mm, the needling frequency is 500-2000 times/min, and the needling stepping amount is 4-10 mm/needle.

Preferably, the mass fraction of the solution containing the nonwoven material in the step (5) is 2-15%.

Preferably, the additive in the additive solution in the step (6) comprises one or more of sodium tetraborate, glutaraldehyde, sodium sulfate, zinc sulfate, maleic anhydride, phthaloyl chloride, phthalic anhydride, glutaric anhydride, succinic anhydride, phthalic acid, epichlorohydrin, formaldehyde, sodium hydroxide, potassium hydroxide and boric acid, wherein the mass fraction of the additive solution is 10-20%;

The mass fraction of the additive in the solution obtained by mixing in the step (6) is 1-10%;

And (3) the crosslinking temperature in the step (6) is 40-100 ℃, and the crosslinking time is 1-6 h.

Preferably, the freezing treatment of step (6) comprises the steps of:

Freezing for 2-8 hours at 0-20 ℃, thawing for 1-5 hours at 5-30 ℃ after the freezing is finished, and repeating the process for 2-5 times to finish the freezing treatment.

The invention also provides the high-strength hydrogel/superfine fiber nonwoven composite material prepared by the preparation method of the high-strength hydrogel/superfine fiber nonwoven composite material.

The invention also provides application of the high-strength hydrogel/superfine fiber nonwoven composite material in the field of wound dressing, facial mask or cooling patch.

The beneficial effects of the invention are as follows:

(1) The invention selects the thermoplastic polyvinyl alcohol as one of the raw materials, realizes the water-soluble fiber of the double-component fiber, is environment-friendly, quick and convenient, can realize the complete cracking of the fiber, solves the problems of high energy consumption, easy environmental pollution, difficult fiber opening and the like of common orange-peel and sea-island double-component fibers in the fiber opening process, and in addition, the diversity of the selection of the other raw materials and the diversity of the fiber cross-section structure provide wider application value for the double-component carding-needling non-woven material of the water-soluble polyvinyl alcohol.

(2) The invention selects a specific drafting process, provides a better performance foundation for the subsequent process, and selects a specific carding and reinforcing process, so that the prepared material has the characteristics of good isotropy, excellent mechanical property, compact structure and the like.

(3) Based on the existence form of the polyvinyl alcohol component in the prepared high-strength hydrogel/superfine fiber non-woven composite material, the prepared high-strength hydrogel/superfine fiber non-woven composite material takes superfine fibers as a framework, realizes the mutual coating between the hydrogel and the superfine fibers, has ultrahigh mechanical strength, and has good application prospect in the fields of masks, wound dressings, cooling patches and the like.

Drawings

FIG. 1 is a schematic diagram of a conjugated double-component melt spinning machine in the invention, in FIG. 1, 2-1 is a feeding port A,2-2 is a screw A,2-3 is a feeding port B,2-4 is a screw B,2-5 is a metering pump, 2-6 is an orange-peel or sea-island type spinning component, 2-7 is a fiber bundle, and 2-8 is a winding device;

FIG. 2 is a schematic diagram of a constant temperature draft box according to the present invention, in FIG. 2, 3-1 is a draft roller 1,3-2 is a draft roller 2,3-3 is a draft roller 3,3-4 is a draft roller 4,3-5 is a constant temperature draft box, and 3-6 is a heating wire;

FIG. 3 is a schematic illustration of a process for preparing a high strength hydrogel/microfiber nonwoven composite material of the present invention;

FIG. 4 is a schematic view of a water-soluble polyvinyl alcohol bicomponent carded-needled nonwoven material and a high-strength hydrogel/ultrafine fiber nonwoven composite material of the invention, in FIG. 4, 4-1 is the water-soluble polyvinyl alcohol bicomponent carded-needled nonwoven material, 4-2 is the fiber cross-sectional structure of the water-soluble polyvinyl alcohol bicomponent carded-needled nonwoven material, 4-3 is the high-strength hydrogel/ultrafine fiber nonwoven composite material, and 4-4 is the fiber cross-sectional structure of the high-strength hydrogel/ultrafine fiber nonwoven composite material;

FIG. 5 is an electron micrograph of the water-soluble polyvinyl alcohol bicomponent carded-needled nonwoven at 300 Xof example 1;

FIG. 6 is an electron micrograph of the water-soluble polyvinyl alcohol bicomponent carded-needled nonwoven at 500 Xof example 1;

FIG. 7 is an electron micrograph of the high strength hydrogel/microfiber nonwoven composite at 500 Xmagnification of example 1;

FIG. 8 is an electron micrograph of the high strength hydrogel/microfiber nonwoven composite at 255 times of example 1;

FIG. 9 is a graph showing the diameter distribution of ultrafine fibers in the high-strength hydrogel/ultrafine fiber nonwoven composite material of example 1.

Detailed Description

In the present invention, the weight average molecular weight of the thermoplastic polyvinyl alcohol in the step (1) is preferably 6600-7200, more preferably 6700-7100, more preferably 6800-7000, the alcoholysis degree of the thermoplastic polyvinyl alcohol is preferably 88-99%, more preferably 90-98%, more preferably 92-95%, the polymerization degree of the thermoplastic polyvinyl alcohol is preferably 300-700, more preferably 400-600, more preferably 500, and the melt flow index of the thermoplastic polyvinyl alcohol is preferably 31-52 g/10min, more preferably 35-45 g/10min, more preferably 40-42 g/10min.

In the present invention, the thermoplastic polyvinyl alcohol of step (1) is prepared according to patent CN116876153 a.

In the present invention, the second polymer preferably comprises polyester, polyamide, poly (adipic acid)/poly (butylene terephthalate), or poly (lactic acid).

In the present invention, the mass ratio of the first polymer to the second polymer is preferably 1 to 5:5 to 9, more preferably 2 to 4:6 to 8, and still more preferably 3:7.

In the invention, in the step (1), melting and spinning are preferably carried out in a conjugated double-component melt spinning machine, as shown in a schematic view of FIG. 1, a first polymer and a second polymer are respectively added into a feeding port A2-1 and a feeding port B2-3, respectively extruded by a screw A2-2 and a screw B2-4, then measured by a metering pump 2-5, and finally subjected to composite spinning by an orange-petal type or sea-island type spinning component 2-6, the spun fibers are bundled to obtain fiber bundles 2-7, and finally the fiber bundles are wound on a silk cylinder by a winding device 2-8 to form the water-soluble polyvinyl alcohol double-component fibers, wherein the cross-section structure of the water-soluble polyvinyl alcohol double-component fibers preferably comprises sea-island type, orange-petal type or sea-island type.

In the invention, the temperature of the screw A is preferably set to be 1 zone 190-210 ℃,2 zone 200-220 ℃,3 zone 210-220 ℃,4 zone 210-230 ℃,5 zone 220-240 ℃, more preferably set to be 1 zone 195-205 ℃,2 zone 205-215 ℃,3 zone 212-218 ℃,4 zone 215-225 ℃,5 zone 225-235 ℃, more preferably set to be 1 zone 200 ℃,2 zone 210 ℃,3 zone 215 ℃,4 zone 220 ℃ and 5 zone 230 ℃, and the temperature of the screw B is preferably set to be 1 zone 170-190 ℃,2 zone 190-210 ℃,3 zone 210-230 ℃,4 zone 215-235 ℃,5 zone 230-240 ℃, more preferably set to be 1 zone 175-185 ℃,2 zone 195-205 ℃,3 zone 215-225 ℃,4 zone 220-230 ℃,5 zone 232-238, more preferably set to be 1 zone 180 ℃,2 zone 200 ℃ and 5 zone 220 ℃,4 zone 220 ℃ and 5 zone 220 ℃.

In the invention, the die temperature of the composite spinning in the step (1) is preferably 230-250 ℃, more preferably 235-245 ℃, more preferably 240 ℃, the speed of the composite spinning is preferably 500-4000 m/min, more preferably 1000-3500 m/min, more preferably 2000-3000 m/min, and the cooling air temperature of the composite spinning is preferably 10-20 ℃, more preferably 12-18 ℃, more preferably 15 ℃.

In the invention, in the step (2), the water-soluble polyvinyl alcohol bicomponent fiber wound on the yarn cylinder is unreeled and then drafted, the draft is preferably carried out in a constant temperature draft box, the schematic diagram of the constant temperature draft box is shown in figure 2, the temperature in the whole constant temperature draft box body 3-5 is kept constant through electric heating, the heating wire is 3-6, so that the fiber is heated uniformly, the constant temperature draft box has a multi-stage draft structure and has 4 draft rollers 3-1, 3-2, 3-3 and 3-4,3 draft areas.

In the invention, the drafting mode in the step (2) is preferably dry-hot drafting, the dissolution of the polyvinyl alcohol component can be avoided by adopting the dry-hot drafting mode, the drafting temperature is preferably 95-105 ℃, more preferably 97-103 ℃, more preferably 100-101 ℃, the drafting multiplying power (the ratio of the speed of the drafting roller 3-4 to the speed of the drafting roller 3-1) is preferably 3.5-5.5 times, more preferably 4-5 times, more preferably 4.5 times, the specific drafting multiplying power realizes the full drafting of the water-soluble polyvinyl alcohol bicomponent fiber, and the mechanical property of the water-soluble polyvinyl alcohol bicomponent fiber is further improved through drafting.

In the invention, after the drafting in the step (2) is finished, the obtained sample is cut by a fiber cutter to obtain short fibers, wherein the length of the short fibers is preferably 20-60 mm, more preferably 30-50 mm, and even more preferably 40-45 mm.

In the invention, the carding in the step (3) is preferably carried out in a high-speed cluttering carding machine, the carding mode is preferably high-speed cluttering carding, and the sufficient cluttering of the short fibers is realized through a triangular vortex area between a cylinder and a cluttering roller, so that isotropy of the polyvinyl alcohol bicomponent fiber web is realized.

In the invention, the reinforcement mode in the step (4) is preferably needling, the needling is preferably performed in an active elliptical track high-speed needling machine, the needling density is preferably 500-1500 needling/cm ², more preferably 800-1200 needling/cm ², more preferably 900-1000 needling/cm ², the needling depth is preferably 4-8 mm, more preferably 5-7 mm, more preferably 6mm, the needling frequency is preferably 500-2000 times/min, more preferably 1000-1500 times/min, more preferably 1200-1300 times/min, and the needling stepping amount is preferably 4-10 mm/needle, more preferably 5-9 mm/needle, more preferably 6-8 mm/needle.

In the invention, the water-soluble polyvinyl alcohol two-component carding-needling non-woven material obtained in the step (4) can be used in the fields of filter materials, superfine fiber synthetic leather or wiping materials, the surface density of the water-soluble polyvinyl alcohol two-component carding-needling non-woven material is 300-900 g/m ², the longitudinal tensile breaking strength is 880-1100N (test standard GB/T24218.3-2010), the longitudinal tensile breaking elongation is 22-40% (test standard GB/T24218.3-2010), the transverse tensile breaking strength is 850-1076N (test standard GB/T24218.3-2010), the transverse tensile breaking elongation is 30-50% (test standard GB/T24218.3-2010), the air permeability is 205-281L/m ²/s (test standard GB/T24218.15-2018), the softness performance score is 71-82 (test standard AATCC (TM 202) and the water-soluble fiber opening rate is 100%.

In the present invention, the mass fraction of the polyvinyl alcohol in the solution containing the nonwoven material in the step (5) is preferably 2 to 15%, more preferably 6 to 12%, and even more preferably 7 to 10%.

In the invention, in the step (5), the water-soluble polyvinyl alcohol double-component carding-needling non-woven material is placed in a die containing water (the water-soluble polyvinyl alcohol double-component carding-needling non-woven material has the same size as a grinding tool, so that on one hand, the collapse of the non-woven material structure after the polyvinyl alcohol is dissolved in water can be avoided, and on the other hand, the uniform dispersion of the polyvinyl alcohol component in the non-woven material structure is facilitated), the water-soluble fiber-breaking treatment is carried out, and after the polyvinyl alcohol component is dissolved, the water-soluble fiber-breaking treatment is completed, so that the solution containing the non-woven material is obtained.

In the invention, the temperature of the water-soluble fiber treatment is determined according to the alcoholysis degree of the thermoplastic polyvinyl alcohol, when the alcoholysis degree of the thermoplastic polyvinyl alcohol is 88-90%, the temperature of the water-soluble fiber treatment is more than or equal to 60 ℃, when the alcoholysis degree of the thermoplastic polyvinyl alcohol is 90-95% and does not contain 90%, the temperature of the water-soluble fiber treatment is more than or equal to 80 ℃, and when the alcoholysis degree of the thermoplastic polyvinyl alcohol is 95-99% and does not contain 95%, the temperature of the water-soluble fiber treatment is more than or equal to 90 ℃.

In the invention, the additive in the additive solution in the step (6) preferably comprises one or more of sodium tetraborate, glutaraldehyde, sodium sulfate, zinc sulfate, maleic anhydride, phthaloyl chloride, phthalic anhydride, glutaric anhydride, succinic anhydride, phthalic acid, epichlorohydrin, formaldehyde, sodium hydroxide, potassium hydroxide and boric acid, and the mass fraction of the additive solution is preferably 10-20%, more preferably 12-18%, and even more preferably 15-16%.

In the present invention, the mass fraction of the additive in the solution obtained by mixing in the step (6) is preferably 1 to 10%, more preferably 3 to 8%, still more preferably 5 to 6%.

In the invention, the temperature of the crosslinking in the step (6) is preferably 40-100 ℃, more preferably 50-90 ℃, still more preferably 70-80 ℃, and the time of the crosslinking is preferably 1-6 h, more preferably 2-5 h, still more preferably 3-4 h.

In the invention, after the cross-linking in the step (6), the mould is placed in an ultrasonic instrument to carry out ultrasonic treatment so as to remove bubbles in the system, and finally, freezing treatment is carried out, after the freezing treatment is finished, the solution is in a hydrogel shape, namely the high-strength hydrogel/superfine fiber nonwoven composite material, wherein the ultrasonic treatment temperature is preferably 50-100 ℃, more preferably 60-90 ℃, more preferably 70-80 ℃, and the ultrasonic treatment time is preferably 1-6 h, more preferably 2-5 h, more preferably 3-4 h.

In the present invention, the freezing treatment of step (6) preferably comprises the steps of:

In the present invention, the freezing treatment of step (6) further preferably comprises the steps of:

Freezing for 3-7 h at-5 to-15 ℃, thawing for 2-4 h at 10-25 ℃ after the freezing is finished, and repeating the processes for 3-4 times to finish the freezing treatment.

In the present invention, the freezing treatment of step (6) more preferably comprises the steps of:

Freezing for 4-6 hours at the temperature of minus 10 to minus 12 ℃, thawing for 3-3.5 hours at the temperature of 15-20 ℃ after the freezing is finished, and repeating the process for 3 times to finish the freezing treatment.

The preparation flow of the high-strength hydrogel/superfine fiber nonwoven composite material is schematically shown in fig. 3.

In FIG. 4, 4-1 is a water-soluble polyvinyl alcohol two-component carding-needling non-woven material, 4-2 is a fiber cross-section structure of the water-soluble polyvinyl alcohol two-component carding-needling non-woven material, 4-3 is a high-strength hydrogel/superfine fiber non-woven composite material, and 4-4 is a fiber cross-section structure of the high-strength hydrogel/superfine fiber non-woven composite material. As can be seen from FIG. 4, the cross-sectional structure of the fiber of the water-soluble polyvinyl alcohol bicomponent carding-needling nonwoven material can be sea-island type, orange-petal-indefinite-island type or sea-island-indefinite-island type (shown as 4-3), and after the fiber is prepared into the high-strength hydrogel/superfine fiber nonwoven composite material, the polyvinyl alcohol component in the fiber is dissolved, and the cross-sectional structure of the fiber after dissolution is shown as 4-4.

The invention also provides the high-strength hydrogel/superfine fiber nonwoven composite material prepared by the preparation method of the high-strength hydrogel/superfine fiber nonwoven composite material, wherein the tensile breaking strength of the high-strength hydrogel/superfine fiber nonwoven composite material is 12-14 MPa, and the water absorption rate can reach 450-1020%.

The technical solutions provided by the present invention are described in detail below with reference to examples, but they should not be construed as limiting the scope of the present invention.

Example 1

Respectively adding thermoplastic polyvinyl alcohol (weight average molecular weight is 7000, alcoholysis degree is 98%, polymerization degree is 500, melt flow index is 40g/10 min) and polylactic acid into a feeding port A2-1 (thermoplastic polyvinyl alcohol) and a feeding port B2-3 (polylactic acid), respectively extruding through a screw A2-2 and a screw B2-4, measuring through a metering pump 2-5, carrying out composite spinning through an orange-type spinning component 2-6, bundling the obtained fiber to obtain a fiber bundle 2-7, and finally winding the fiber bundle on a silk cylinder through a winding device 2-8 to form a water-soluble polyvinyl alcohol bicomponent fiber with a cross-section structure of orange-type, wherein the mass ratio of the thermoplastic polyvinyl alcohol to the polylactic acid is 3:7, and in the spinning process, the temperature of the screw A is set to be 1 zone 200 ℃,2 zone 210 ℃,3 zone 215 ℃,4 zone 220 ℃,5 zone 230 ℃, the temperature of the screw B is set to be 1 zone 180 ℃,2 zone 200 ℃,3 zone 220 ℃,4 zone 235 ℃ and the temperature of the 5 zone 230 ℃ and the temperature of a cooling die head is 1000 ℃ in the spinning speed;

Unwinding water-soluble polyvinyl alcohol bicomponent fiber wound on a wire drum, carrying out dry heat drafting in a constant temperature drafting box, keeping the temperature in the whole constant temperature drafting box body 3-5 constant by electric heating, setting the drafting temperature to be 100 ℃ by heating wires, setting the constant temperature drafting box to have a multi-stage drafting structure with 4 drafting rollers 3-1, 3-2, 3-3, 3-4 and 3 drafting areas, setting the drafting multiplying power to be 3.5 times, and cutting the drafting box into short fibers of 30mm by adopting a fiber cutter after the drafting is finished;

Carding the short fibers by a high-speed disordered carding machine to obtain a polyvinyl alcohol double-component fiber web, then reinforcing (needling) the polyvinyl alcohol double-component fiber web by an active elliptic track high-speed needling machine, wherein the process parameters of the active elliptic track high-speed needling machine are as follows, needling density is 1500 spines/cm ², depth is 8mm, frequency is 1000 times/min, and stepping amount is 8 mm/needle;

Placing a water-soluble polyvinyl alcohol double-component carding-needling non-woven material in a mold containing water (the water-soluble polyvinyl alcohol double-component carding-needling non-woven material has the same size as a grinding tool), carrying out water-soluble fiber-opening treatment at 90 ℃, completing the water-soluble fiber-opening treatment after the polyvinyl alcohol component is dissolved to obtain a solution containing the non-woven material (the mass fraction of the polyvinyl alcohol in the solution containing the non-woven material is 6%), adding a sodium hydroxide solution with the mass fraction of 15%, mixing, wherein the mass fraction of the sodium hydroxide in the mixed solution is 5%, crosslinking for 4 hours at 70 ℃, placing the mold in an ultrasonic instrument at 80 ℃ for ultrasonic treatment for 2 hours after the crosslinking is finished, freezing for 6 hours at-5 ℃, thawing for 2 hours at 20 ℃ after the freezing is finished, and repeating the process for 5 times to obtain the high-strength hydrogel/superfine fiber non-woven composite material.

An electron microscope image of the water-soluble polyvinyl alcohol bicomponent carding-needling non-woven material at 300 times is shown in fig. 5, an electron microscope image of the water-soluble polyvinyl alcohol bicomponent carding-needling non-woven material at 500 times is shown in fig. 6, an electron microscope image of the high-strength hydrogel/superfine fiber non-woven composite material at 500 times is shown in fig. 7, and an electron microscope image of the high-strength hydrogel/superfine fiber non-woven composite material at 255 times is shown in fig. 8. As can be obtained from fig. 5 to 8, the average diameter of the composite fibers in the water-soluble polyvinyl alcohol two-component carding-needling non-woven material is 25 μm, the fiber distribution is loose, the high-strength hydrogel/superfine fiber non-woven composite material prepared by water-soluble fiber opening and crosslinking is characterized in that the superfine fibers and the hydrogel are uniformly distributed, and the hydrogel is filled in the three-dimensional structure of the superfine fiber non-woven material.

The superfine fibers in the prepared high-strength hydrogel/superfine fiber nonwoven composite material were subjected to microscopic morphology shooting by a table scanning electron microscope, and the diameter of the superfine fibers was measured by a particle size distribution software, so as to obtain a diameter distribution diagram of the superfine fibers in the high-strength hydrogel/superfine fiber nonwoven composite material in this example, as shown in fig. 9. As can be seen from FIG. 9, the equivalent diameter of the ultrafine fibers in the high-strength hydrogel/ultrafine fiber nonwoven composite material of this example was 4.1. Mu.m.

Example 2

The other conditions in example 1 were controlled to be unchanged, the alcoholysis degree of the thermoplastic polyvinyl alcohol was modified to 88%, and the water-soluble polyvinyl alcohol bicomponent carded-needled nonwoven material was obtained without the "placing the water-soluble polyvinyl alcohol bicomponent carded-needled nonwoven material in a mold containing water for water-soluble fiber-opening treatment" and the subsequent steps.

Example 3

The other conditions in example 1 were controlled to be unchanged, the mass ratio of the thermoplastic polyvinyl alcohol to the polylactic acid was modified to be 5:5, and the water-soluble polyvinyl alcohol bicomponent carding-needling nonwoven material was obtained without the "placing the water-soluble polyvinyl alcohol bicomponent carding-needling nonwoven material in a mold containing water for water-soluble fiber-opening treatment" and the subsequent steps.

Example 4

The other conditions in example 1 were controlled to be unchanged, the draft ratio was modified to be 4.5 times, and the process of "placing a water-soluble polyvinyl alcohol two-component carding-needling nonwoven material in a mold containing water to perform water-soluble fiber-opening treatment" and thereafter was not performed to obtain a water-soluble polyvinyl alcohol two-component carding-needling nonwoven material.

Example 5

The other conditions in example 1 were controlled to be unchanged, the draft ratio was modified to be 5.5 times, the mass ratio of thermoplastic polyvinyl alcohol to polylactic acid was 8:2, and the water-soluble polyvinyl alcohol bicomponent carded-needled nonwoven material was obtained without "placing the water-soluble polyvinyl alcohol bicomponent carded-needled nonwoven material in a mold containing water for water-soluble fiber-opening treatment" and the subsequent steps.

Example 6

The other conditions in example 1 were controlled to be unchanged, and the mass fraction of polyvinyl alcohol in the solution containing the nonwoven material was modified to be 9% to obtain a high-strength hydrogel/ultrafine fiber nonwoven composite material.

Example 7

The other conditions in example 1 were controlled to be unchanged, and the mass fraction of polyvinyl alcohol in the solution containing the nonwoven material was modified to be 12% to obtain a high-strength hydrogel/ultrafine fiber nonwoven composite material.

Example 8

The other conditions in example 1 were controlled to be unchanged, the alcoholysis degree of the thermoplastic polyvinyl alcohol was modified to 88%, and the temperature of the water-soluble fiber-opening treatment was modified to 60 ℃ to obtain a high-strength hydrogel/ultrafine fiber nonwoven composite material.

The performance of the water-soluble polyvinyl alcohol bicomponent carded-needled nonwoven materials of examples 1 to 5 was tested, and the performance test results of the water-soluble polyvinyl alcohol bicomponent carded-needled nonwoven materials of examples 1 to 5 were obtained as shown in table 1. Specifically, the test method is as follows:

(1) Determination of tensile breaking Properties

The tensile fracture performance was measured by using a nonwoven material electronic universal tester (CZ-4000D 1, chang taimen test machinery Co., ltd., china), and the water-soluble polyvinyl alcohol two-component carding-needling nonwoven material was cut into a rectangle with a specification of 200mm long and 50mm wide according to the standard GB/T24218.3-2010, the holding distance of the instrument was 100mm, the tensile speed was 100mm/min, and the test was conducted 5 times, and the average value was calculated.

(2) Determination of air permeability

The air permeability performance is tested by adopting a full-automatic air permeability measuring instrument (YG 461E-III type, ningbo textile instruments factory, china), according to the standard GB/T24218.15-2018 part 15 of the test method of textile non-woven fabrics, the air permeability is set to be in a full-automatic mode, the unit is L/m ²/s, a water-soluble polyvinyl alcohol bi-component carding-needling non-woven material is placed under a holder of the air permeability measuring instrument, and each process sample is measured for 5 times, and then the average value is obtained.

(3) Softness test

A PhabrOmeter hand feeling test method is adopted to test softness performance of a French treasury instrument (F1S 3-10, U.S.) according to the standard AATCC TM202 fabric clothing relative hand feeling value evaluation of instrumental law, a disc sampler with a sampling area of 100cm ² is used for sampling, a weight with the mass of 100g is added on the instrument, the softness performance of the sample is measured according to the soft score (the score is 1-100 and the best 100 time minute) displayed by the instrument, and the samples of each process are measured for 3 times respectively and are averaged.

Table 1 Performance test results of the water-soluble polyvinyl alcohol two-component carded-needled nonwovens of examples 1-5

Case (B)	Example 1	Example 2	Example 3	Example 4	Example 5
						Areal density (g/m ²)	600	500	550	700	700
Softness score	71	74	72	78	82
						Longitudinal tensile strength (N)	916	894	880	1023	1100
Elongation at break in machine direction (%)	32	34	40	28	22
						Transverse tensile strength (N)	942	882	860	984	1076
Elongation at break in transverse direction (%)	47	45	50	41	31
						Air permeability (L/m ²/s)	205	231	255	274	281

The performance of the high strength hydrogel/ultrafine fiber nonwoven composites obtained in example 1 and examples 6 to 8 was tested, and the performance test results of the high strength hydrogel/ultrafine fiber nonwoven composites in example 1 and examples 6 to 8 were obtained as shown in table 2. Specifically, the test method is as follows:

(1) Determination of tensile breaking Properties

The mechanical properties of the high strength hydrogel/microfiber nonwoven composite were characterized by measuring its tensile strength, cutting the sample into dumbbell shapes, and stretching at a stable strain rate of 1mm/min until fracture. Each experiment was repeated for 3 groups and the average was taken.

(2) Water absorption measurement

The method comprises the steps of immersing different samples of 15mm multiplied by 15mm in distilled water at 20-30 ℃ for the same time, taking out, removing redundant solution on a nylon bag, and then weighing the mass of the solution, wherein the water absorption multiplying power at the saturation moment can be calculated by the following formula:

Wherein W _s is the mass of the swollen hydrogel at time t, W _d is the dry weight of the sample, 3 parallel experiments are repeated, and the water absorption rate is the average value of 3 experiments.

Table 2 results of performance testing of the high strength hydrogel/microfiber nonwoven composites of example 1 and examples 6-8

According to the test results, the water-soluble polyvinyl alcohol two-component carding-needling non-woven material prepared by the method has a longitudinal tensile breaking strength of 880-1100N (the test standard is GB/T24218.3-2010), a longitudinal tensile breaking elongation of 22-40% (the test standard is GB/T24218.3-2010), a transverse tensile breaking strength of 850-1076N (the test standard is GB/T24218.3-2010), a transverse tensile breaking elongation of 30-50% (the test standard is GB/T24218.3-2010), air permeability of 205-281L/m ²/s (the test standard is GB/T24218.15-2018), softness score of 71-82 (the test standard is AATCC TM 202), a water-soluble fiber breaking rate of 100%, and a tensile breaking strength of the high-strength hydrogel/superfine fiber non-woven composite material is 9-14 MPa, and a water absorption rate of 450-1020%.

The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.

Claims

1. A method for preparing a high-strength hydrogel/superfine fiber non-woven composite material, which is characterized by comprising the following steps:

(6) Mixing a solution containing a non-woven material with an additive solution, and sequentially performing crosslinking and freezing treatment to obtain the high-strength hydrogel/superfine fiber non-woven composite material;

The weight average molecular weight of the thermoplastic polyvinyl alcohol in the step (1) is 6600-7200, the alcoholysis degree of the thermoplastic polyvinyl alcohol is 88-99%, the polymerization degree of the thermoplastic polyvinyl alcohol is 300-700, and the melt flow index of the thermoplastic polyvinyl alcohol is 31-52 g/10min;

The mass ratio of the first polymer to the second polymer is 1-5:5-9;

The drafting mode in the step (2) is dry heat drafting, the temperature of the drafting is 95-105 ℃, and the multiplying power of the drafting is 3.5-5.5 times;

the reinforcement mode in the step (4) is needling, the needling density is 500-1500 needling/cm ², the needling depth is 4-8 mm, the needling frequency is 500-2000 times/min, and the needling stepping amount is 4-10 mm/needle;

when the alcoholysis degree of the thermoplastic polyvinyl alcohol is 88-90%, the temperature of the water-soluble fiber treatment is more than or equal to 60 ℃, when the alcoholysis degree of the thermoplastic polyvinyl alcohol is 90-95% and does not contain 90%, the temperature of the water-soluble fiber treatment is more than or equal to 80 ℃, and when the alcoholysis degree of the thermoplastic polyvinyl alcohol is 95-99% and does not contain 95%, the temperature of the water-soluble fiber treatment is more than or equal to 90 ℃.

2. The method of making a high strength hydrogel/microfiber nonwoven composite material according to claim 1 wherein the second polymer comprises polyester, polyamide, polybutylene terephthalate-adipate, or polylactic acid.

3. The method for preparing the high-strength hydrogel/ultrafine fiber nonwoven composite material according to claim 1 or 2, wherein the die temperature of the composite spinning in the step (1) is 230-250 ℃, and the speed of the composite spinning is 500-4000 m/min.

4. The method for preparing a high-strength hydrogel/ultrafine fiber nonwoven composite material according to claim 3, wherein the mass fraction of polyvinyl alcohol in the solution containing the nonwoven material in the step (5) is 2-15%.

5. The method for preparing the high-strength hydrogel/superfine fiber nonwoven composite material according to claim 4, wherein the additive in the additive solution in the step (6) comprises one or more of sodium tetraborate, glutaraldehyde, sodium sulfate, zinc sulfate, maleic anhydride, phthaloyl chloride, phthalic anhydride, glutaric anhydride, succinic anhydride, phthalic acid, epichlorohydrin, formaldehyde, sodium hydroxide, potassium hydroxide and boric acid, and the mass fraction of the additive solution is 10-20%;

6. The method of preparing a high strength hydrogel/microfiber nonwoven composite material according to claim 5, wherein the freezing process of step (6) comprises the steps of:

7. The high-strength hydrogel/ultrafine fiber nonwoven composite material prepared by the method for preparing the high-strength hydrogel/ultrafine fiber nonwoven composite material according to any one of claims 1-6.

8. The use of the high strength hydrogel/microfiber nonwoven composite of claim 7 in the field of wound dressing, facial mask or cooling patches.