Search

CN-121992546-A - High-strength antibacterial bio-based composite yarn and preparation method thereof

CN121992546ACN 121992546 ACN121992546 ACN 121992546ACN-121992546-A

Abstract

The invention belongs to the technical field of textile materials and provides a high-strength antibacterial bio-based composite yarn and a preparation method thereof, wherein the preparation method comprises the following steps of S1, dissolving chitosan in an acetic acid aqueous solution to form a spinning solution, carrying out wet spinning, coagulating bath forming and solvent replacement, and then carrying out supercritical CO 2 drying to obtain chitosan aerogel fibers; S2, carrying out opening mixing on chitosan aerogel fibers and lyocell fibers, spinning the chitosan aerogel fibers and the lyocell fibers into uncrosslinked composite yarns through a ring spinning process, and S3, carrying out pretreatment on the uncrosslinked composite yarns by using a CA aqueous solution, carrying out crosslinking reaction by using an EGDE aqueous solution after washing and drying, and obtaining the high-strength antibacterial bio-based composite yarns after washing and drying. According to the invention, the chitosan aerogel fiber and the lyocell fiber are subjected to multi-step crosslinking treatment after being subjected to composite spinning, so that the mechanical property is improved, meanwhile, the antibacterial property is reserved and enhanced, the cooperative optimization of the material property is realized, and the tensile strength, antibacterial durability and service comfort of the composite yarn can be remarkably improved.

Inventors

  • LUO WENLI
  • JIANG YANNI
  • She Zuoxian

Assignees

  • 成都纺织高等专科学校

Dates

Publication Date
20260508
Application Date
20260121

Claims (10)

  1. 1. The preparation method of the high-strength antibacterial bio-based composite yarn is characterized by comprising the following steps of: S1, preparing chitosan aerogel fibers, namely dissolving chitosan in acetic acid aqueous solution to form spinning solution, filling the spinning solution into a spinning pump after vacuum defoamation, extruding the spinning solution through a spinneret plate, then entering an alkaline coagulation bath taking ethanol as a main body for wet spinning, forming wet gel fibers through the wet spinning, carrying out solvent displacement on the wet gel fibers by using ethanol to remove water, and then drying by using a supercritical CO 2 drying device to obtain the chitosan aerogel fibers with porous structures; s2, ring spinning to prepare uncrosslinked composite yarns, namely putting the chitosan aerogel fibers and the lyocell fibers prepared in the step S1 into a cotton opener for opening and mixing to prepare a mixed fiber layer, and spinning the mixed fiber layer into the lyocell/chitosan composite yarns through a ring spinning procedure; S3, multi-step sequential crosslinking strengthening treatment, namely immersing the uncrosslinked composite yarn prepared in the step S2 in a citric acid aqueous solution for pretreatment, taking out the pretreated composite yarn for cleaning and drying, immersing the pretreated and dried composite yarn in an ethylene glycol diglycidyl ether aqueous solution for crosslinking reaction, and taking out the crosslinked composite yarn for cleaning and drying to obtain the high-strength antibacterial bio-based composite yarn.
  2. 2. The method of claim 1, wherein in the step S1, the chitosan is chitosan powder with a deacetylation degree of 90% or more and a viscosity of 100-500 mPa.s, the concentration of the aqueous acetic acid solution is 1-3% (v/v), and the concentration of the chitosan is 4.0-6.0% (w/v).
  3. 3. The method for preparing the high-strength antibacterial bio-based composite yarn according to claim 1 or 2, wherein in the step S1, when chitosan is dissolved in an acetic acid aqueous solution, stirring the acetic acid aqueous solution in a water bath at 40-50 ℃ is continued for 6-8 hours until a uniform, transparent and bubble-free viscous chitosan spinning solution is formed.
  4. 4. The method for preparing the high-strength antibacterial bio-based composite yarn according to claim 1, wherein in the step S1, the aperture of a spinneret plate adopted by the wet spinning is 0.08-0.12 mm, the alkali contained in the coagulating bath is sodium hydroxide, the spinning temperature is 25 ℃, and the residence time in the coagulating bath is 2-5 minutes.
  5. 5. The method of claim 1, wherein in step S1, the critical temperature of the supercritical CO 2 is not less than 31 ℃, and the critical pressure is not less than 7.4 MPa.
  6. 6. The method of claim 1, wherein in step S2, before the chitosan aerogel fiber and the lyocell fiber are put into a cotton opener for opening and mixing, the chitosan aerogel fiber and the lyocell fiber are balanced for 24 hours under the standard temperature and humidity conditions of 20+/-2 ℃ and 65+/-3% of relative humidity, and the lyocell fiber and the chitosan aerogel fiber are mixed according to the dry weight ratio range of 9~1.
  7. 7. The method for preparing a high-strength antimicrobial bio-based composite yarn according to claim 1 or 6, wherein in the step S2, the ring spinning process comprises the steps of: Carding, namely separating single fibers from the mixed fiber layer through a carding machine, removing short piles and impurities, outputting uniform fiber net, and collecting Shu Chengsheng fiber net strips; drawing, namely drawing the raw strips into cooked strips with uniform thickness through a plurality of steps of merging and drafting; Drawing the cooked sliver into coarse yarn by a coarse yarn machine; and spinning, namely further drafting the roving to the target fineness by adopting a ring spinning frame, applying twist by high-speed rotation of a ring and a bead ring, setting the twist coefficient at 380-420, and spinning to obtain the lyocell/chitosan composite yarn.
  8. 8. The method of claim 1, wherein in step S3, the concentration of the aqueous solution of citric acid is 8% (w/v), and the pretreatment process is performed in a constant temperature water bath with a bath ratio of 1:30 and a temperature of 80 ℃ for 40 minutes.
  9. 9. The method of preparing a high-strength antimicrobial bio-based composite yarn according to claim 1 or 8, wherein in the step S3, the concentration of the ethylene glycol diglycidyl ether aqueous solution is 2.5% (v/v), and the crosslinking reaction process conditions are a bath ratio of 1:25, a 60 ℃ constant temperature water bath, and a reaction time of 90 minutes.
  10. 10. The high-strength antibacterial bio-based composite yarn is characterized by being prepared by the preparation method of the high-strength antibacterial bio-based composite yarn according to any one of claims 1 to 9.

Description

High-strength antibacterial bio-based composite yarn and preparation method thereof Technical Field The invention belongs to the technical field of textile materials, and particularly relates to a high-strength antibacterial bio-based composite yarn and a preparation method thereof. Background Chitosan is a natural polysaccharide with excellent biocompatibility, antibacterial property and degradability, and is widely applied to the fields of biomedicine, environmental protection, food packaging and the like. However, pure chitosan fibers have poor mechanical properties (strength generally lower than 2 cN/dtex) and high cost, which limit their application in textile and medical materials. In order to improve the yarn performance, common methods comprise spinning technology of chitosan/cotton blended yarn and chitosan/cotton composite yarn reported in antibacterial performance literature of Tianjin textile technology, poor spinning property of chitosan, short maintenance time of antibacterial property of chitosan cotton blended yarn, insufficient strength and complex technology, and the research progress of wool textile technology antibacterial yarn indicates that when the blending ratio of antibacterial polyester to chitin is 70/30, the breaking strength is the maximum and is 32.969 cN/tex, the Coefficient of Variation (CV) is 8.33%, and the antibacterial rate to staphylococcus aureus is only 88.7%. In the prior art, only aiming at the improvement of the fiber strength, the mechanical property is improved by using yarn for post-treatment, and the related report of performance improvement after chitosan and lyocell are hardly generated. Most of chemical cross-linking agents used at present for improving the mechanical properties of fibers are glutaraldehyde, epoxy resin and the like, and the chitosan fibers are cross-linked, so that the strength can be improved, but the fiber embrittlement or biocompatibility reduction is often caused. The closest prior art is that chitosan fiber is adopted and then blended with cotton fiber to obtain yarn with certain antibacterial property, but the yarn is not subjected to systematic crosslinking reinforcement, the tensile strength is low, and the antibacterial property is attenuated along with the increase of washing times. The existing yarn has the defects of insufficient mechanical property, incapability of meeting the application requirements of high-strength textiles, non-durable antibacterial property, obvious attenuation especially after wetting or repeated use, complex processing technology or high cost, such as special equipment for electrostatic spinning, low productivity and easy fiber embrittlement or function reduction caused by a single crosslinking mode. The defects of the existing yarn are that the acting force among chitosan molecular chains is weak, the crystallinity is low, the fiber structure is loose, an antibacterial mechanism depends on the combination of amino groups in chitosan molecules and bacterial cell walls, but the antibacterial mechanism is easy to run off in water environment, the existing composite technology cannot realize the systematic promotion of the interfacial strength among fibers, and a stable three-dimensional network structure cannot be formed due to single cross-linking agent selection or treatment mode. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to provide the composite yarn with high strength, long-acting antibacterial property and good biocompatibility and the preparation method thereof, and the problems of the prior chitosan fiber composite material proposed in the background art are solved by adopting the multi-step crosslinking treatment after the chitosan aerogel fiber and the lyocell fiber are subjected to composite spinning. The invention is realized by the following technical scheme: the preparation method of the high-strength antibacterial bio-based composite yarn comprises the following steps: S1, preparing chitosan aerogel fibers, namely dissolving chitosan in acetic acid aqueous solution to form spinning solution, filling the spinning solution into a spinning pump after vacuum defoamation, extruding the spinning solution through a spinneret plate, then entering an alkaline coagulation bath taking ethanol as a main body for wet spinning, forming wet gel fibers through the wet spinning, carrying out solvent displacement on the wet gel fibers by using ethanol to remove water, and then drying by using a supercritical CO 2 drying device to obtain the chitosan aerogel fibers with porous structures; In the step S1, ethanol is taken as a main body in a coagulating bath, a small amount of alkali is contained, the alkali is used for neutralizing acetic acid, chitosan is separated out from a solution in the coagulating bath for forming, and the acetic acid is neutralized to form wet gel fibers initially; S2, ring spinning to prepare uncrosslinked composite yarns, namely putting