A durable antibacterial regenerated cellulose fiber and preparation method thereof

Abstract

The present invention relates to a durable antibacterial regenerated cellulose fiber and a preparation method thereof, and belongs to the technical field of textile finishing. The preparation method of the present invention comprises the following steps: S1, adding wormwood essential oil and chitosan solution to oxidized sodium alginate solution in sequence, reacting under the condition of pH 6-7, filtering and drying to obtain functional microcapsules with wormwood essential oil as core material, chitosan and oxidized sodium alginate as wall materials; S2, blending the functional microcapsules with spinning solution, and obtaining the durable antibacterial regenerated cellulose fiber through wet spinning, coagulation molding, washing, non-oxidative desulfurization and drying; the spinning solution is a mixture of methyl cellulose and sodium hydroxide. The durable antibacterial regenerated cellulose fiber of the present invention has excellent antibacterial performance and water-washing resistance, with an antibacterial rate of 96.5-99.9% against Escherichia coli and Staphylococcus aureus, and the antibacterial rate is still higher than 80% after 50 washings.

Description

Technical Field

[0001] The invention belongs to the technical field of textile finishing, and in particular relates to a durable antibacterial regenerated cellulose fiber and a preparation method thereof. Background Art

[0002] Mugwort extract, rich in natural substances such as flavonoids, terpenes, eucalyptol, and tannins, has excellent antimicrobial properties and has therefore attracted widespread attention for the antimicrobial functionalization of textiles. Chinese invention patent CN 107268096A discloses a method for preparing mugwort antimicrobial viscose fiber. The method involves adding mugwort extract to plant pulp to produce regenerated cellulose fiber. However, the mugwort extract is volatile, unstable, and poorly compatible with regenerated cellulose fiber, resulting in poor durability of the functional regenerated cellulose fiber. Microencapsulation technology, with its excellent stability and sustained release properties, can effectively address this issue.

[0003] Chinese invention patent CN 113599280A discloses a nano-scale wormwood essential oil microcapsule and its preparation method and application. It adopts lactic acid-glycolic acid polymer (PLGA) and carboxymethyl cellulose to cross-link to form an inner core layer, and ethyl cellulose material as an outer shell layer. It can be used in the field of cosmetics. However, the preparation process of the microcapsule is complicated and the cost is high, and it cannot be applied on a large scale to the preparation of functional viscose fibers. Reference (Zhai Yuanyuan, Liu Yanjun, Wang Jin, et al. Preparation and application of wormwood essential oil antibacterial microcapsules [J]. Journal of Textile Science and Engineering, 2021, 38 (4): 50-56) Using wormwood essential oil as the core material and gelatin and chitosan as the wall materials, wormwood essential oil microcapsules were prepared by complex coacervation method, and then cotton fabrics were post-finished with wormwood essential oil microcapsules through polyurethane coating. Reference (Sun Lijuan. Research on mugwort extract / viscose spunlace nonwoven materials [D]. Tianjin: Tianjin University of Technology, 2021) Using sodium alginate and calcium chloride as wall materials and mugwort extract as core material, mugwort extract microcapsules were prepared by sharp hole-coagulation bath method, and the prepared mugwort extract microcapsules were arranged on the surface of viscose fiber spunlace nonwoven materials. However, the particle size of the microcapsule is about 3 mm, which cannot be used for the addition and modification of functional regenerated cellulose fibers.

[0004] Therefore, there are still great challenges in using mugwort as the core material to prepare microcapsules with good compatibility with regenerated cellulose fibers for the addition and modification of functional regenerated cellulose fibers. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a long-lasting antibacterial regenerated cellulose fiber and a preparation method thereof. First, functional microcapsules are prepared with mugwort essential oil as the core material and chitosan and oxidized sodium alginate as the wall materials. Then, the functional microcapsules are added to the regenerated cellulose fiber spinning solution and mixed evenly. The long-lasting antibacterial regenerated cellulose fiber is prepared by wet spinning.

[0006] The first object of the present invention is to provide a method for preparing durable antibacterial regenerated cellulose fiber, comprising the following steps:

[0007] S1, adding wormwood essential oil and chitosan solution to oxidized sodium alginate solution in sequence, reacting at a pH of 6-7, filtering and drying to obtain functional microcapsules with wormwood essential oil as the core material and chitosan and oxidized sodium alginate as the wall materials;

[0008] S2. The functional microcapsules described in S1 are blended with a spinning solution, and the durable antibacterial regenerated cellulose fibers are obtained by wet spinning, coagulation molding, washing, non-oxidative desulfurization and drying; the spinning solution is a mixture of methyl cellulose and sodium hydroxide.

[0009] In one embodiment of the present invention, in S1, the mass fraction of the chitosan solution is 0.75%-1.25%, the pH of the chitosan solution is 4-5, the pH regulator is acetic acid and / or citric acid, and chitosan is easily soluble in acidic solutions.

[0010] In one embodiment of the present invention, in S1, the mass fraction of the oxidized sodium alginate solution is 0.5%-2.0%.

[0011] In one embodiment of the present invention, in S1, the mass ratio of chitosan to oxidized sodium alginate is 1-2:1.

[0012] In one embodiment of the present invention, in S1, the diameter of the functional microcapsules is 1.5 μm-3 μm, the mass ratio of the core material to the wall material is 1:2-3, and the encapsulation rate of the wormwood essential oil is 63%-68%.

[0013] In one embodiment of the present invention, in S1, the pH regulator is sodium hydroxide.

[0014] Furthermore, the mass fraction of the sodium hydroxide is 5%-10%.

[0015] In one embodiment of the present invention, in S1, the reaction temperature is 60°C-80°C, and the reaction time is 40min-70min. Under these conditions, the carboxyl groups of the oxidized sodium alginate and the amino groups of the chitosan can produce ionic bonds. In addition, the aldehyde groups of the oxidized sodium alginate can produce Schiff base bonds with the amino groups of the chitosan to form microcapsule wall materials to encapsulate the wormwood essential oil.

[0016] In one embodiment of the present invention, in S1, the drying temperature is 30°C-50°C.

[0017] In one embodiment of the present invention, in S2, the maturity of the spinning solution (10 wt% NH4Cl) is 10 mL-15 mL.

[0018] In one embodiment of the present invention, in S2, the mass fraction of methyl cellulose in the spinning solution is 6%-9%, and the mass fraction of sodium hydroxide is 8%-12%; the amount of the functional microcapsules is 7%-9% of the methyl cellulose content in the spinning solution.

[0019] In one embodiment of the present invention, in S2, the spinning speed of the wet spinning is 30 m / min-50 m / min, and the total draft is 120%-130%.

[0020] In one embodiment of the present invention, in S2, the coagulation molding is carried out in a coagulation bath, the temperature of the coagulation bath is 35°C-45°C; the concentration of sulfuric acid in the coagulation bath is 80g / L-120g / L, the concentration of sodium sulfate is 280g / L-350g / L, and the concentration of zinc sulfate is 10g / L-14g / L.

[0021] The second object of the present invention is to provide a durable antibacterial regenerated cellulose fiber prepared by the method.

[0022] The technical solution of the present invention has the following advantages over the prior art:

[0023] (1) The preparation method described in the present invention utilizes the cationic amino groups of chitosan to react with the anionic carboxyl groups and aldehyde groups of oxidized sodium alginate to form ionic bonds and Schiff base reactions, so that the wall material structure formed is stable, thereby encapsulating the wormwood essential oil to prepare functional microcapsules; the flavonoid components and tannic acid components in the wormwood essential oil are rich in hydroxyl groups, and have good compatibility with chitosan and oxidized sodium alginate; in addition, the main chains of chitosan and oxidized sodium alginate are both glucose rings, which have similar chemical structures to cellulose, so the chitosan / oxidized sodium alginate microcapsules have good compatibility with regenerated cellulose fibers and have little effect on the strength and feel of the regenerated cellulose fibers; the wormwood essential oil, Schiff base structure and chitosan construct a synergistic antibacterial effect, so the functional microcapsules have excellent antibacterial properties, and the wormwood essential oil is dispersed in the regenerated cellulose fibers in a microcapsule state, and its release and volatilization have a sustained release effect, so it has excellent durability.

[0024] (2) The durable antibacterial regenerated cellulose fiber of the present invention has excellent antibacterial properties and water-washing resistance, with an antibacterial rate of 96.5-99.9% against Escherichia coli and Staphylococcus aureus, and the antibacterial rate is still higher than 80% after 50 washes. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0026] Figure 1 This is a scanning electron microscope image of the functional microcapsules prepared in Example 1 of the present invention;

[0027] Figure 2 This is a test chart of the antibacterial performance of the regenerated cellulose fibers of Comparative Example 1 and Example 1 of the present invention. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0029] In the present invention, unless otherwise specified, the mass fraction of cellulose methyl ester in the spinning solution used in the examples is 8%, the mass fraction of sodium hydroxide is 10%; the maturity value of the spinning solution is about 13 mL at 10 wt% NH4Cl.

[0030] In the present invention, unless otherwise specified, the pH of the chitosan solution used in the examples is about 4.5, and the pH regulator is citric acid.

[0031] Example 1

[0032] The durable antibacterial regenerated cellulose fiber and the preparation method thereof of the present invention specifically comprise the following steps:

[0033] S1. Adding wormwood essential oil and 1% chitosan solution to 1.2% oxidized sodium alginate solution in sequence, the mass ratio of chitosan to oxidized sodium alginate is 1.5:1, adding 8% sodium hydroxide by mass to adjust the pH to 6.5, reacting at 70°C for 55 minutes, filtering, and drying at 40°C to obtain functional microcapsules with wormwood essential oil as the core material and chitosan and oxidized sodium alginate as the wall materials. The average diameter of the functional microcapsules is about 2.3 μm, the mass ratio of the core material to the wall material is 1:2.5, and the encapsulation efficiency of the wormwood essential oil is 65%;

[0034] S2. Blend the functional microcapsules with the spinning solution, perform wet spinning at a spinning speed of 40 m / min and a total draft of 125%, coagulate and form the fibers in a coagulation bath at 40°C, wash, perform non-oxidative desulfurization, and dry the fibers to obtain durable antibacterial regenerated cellulose fibers; the amount of the functional microcapsules is 8% of the type A cellulose content in the spinning solution; the concentration of sulfuric acid in the coagulation bath is 100 g / L, the concentration of sodium sulfate is 310 g / L, and the concentration of zinc sulfate is 12 g / L.

[0035] Comparative Example 1

[0036] The process is basically the same as Example 1, except that no functional microcapsules are added, that is, the regenerated cellulose fibers are not modified.

[0037] Comparative Example 2

[0038] The method is basically the same as Example 1, except that chitosan is not added.

[0039] Example 2

[0040] The durable antibacterial regenerated cellulose fiber and the preparation method thereof of the present invention specifically comprise the following steps:

[0041] S1. Adding wormwood essential oil and 0.75% chitosan solution to 0.5% oxidized sodium alginate solution in sequence, the mass ratio of chitosan to oxidized sodium alginate is 1:1, adding 5% sodium hydroxide by mass to adjust the pH to 6, reacting at 60°C for 70 minutes, filtering and drying at 30°C to obtain functional microcapsules with wormwood essential oil as the core material and chitosan and oxidized sodium alginate as the wall materials. The average diameter of the functional microcapsules is about 2 μm, the mass ratio of the core material to the wall material is 1:2, and the encapsulation efficiency of the wormwood essential oil is 63%;

[0042] S2. Blending functional microcapsules with spinning solution, wet spinning is performed at a spinning speed of 30 m / min and a total draft of 120%, and coagulation is performed in a coagulation bath at 35°C, followed by washing, non-oxidative desulfurization, and drying to obtain durable antibacterial regenerated cellulose fibers; the amount of functional microcapsules used is 7% of the type A cellulose content in the spinning solution; the concentration of sulfuric acid in the coagulation bath is 80 g / L, the concentration of sodium sulfate is 280 g / L, and the concentration of zinc sulfate is 10 g / L.

[0043] Example 3

[0044] The durable antibacterial regenerated cellulose fiber and the preparation method thereof of the present invention specifically comprise the following steps:

[0045] S1. Adding wormwood essential oil and 1.25% chitosan solution to 2.0% oxidized sodium alginate solution in sequence, the mass ratio of chitosan to oxidized sodium alginate is 2:1, adding 10% sodium hydroxide by mass to adjust the pH to 6, reacting at 80°C for 40 minutes, filtering, and drying at 50°C to obtain functional microcapsules with wormwood essential oil as the core material and chitosan and oxidized sodium alginate as the wall materials. The average diameter of the functional microcapsules is about 2.5 μm, the mass ratio of the core material to the wall material is 1:3, and the encapsulation efficiency of the wormwood essential oil is 68%;

[0046] S2. Blending functional microcapsules with spinning solution, wet spinning is performed at a spinning speed of 50 m / min and a total draft of 120%-130%, and coagulation is performed in a coagulation bath at 45°C, followed by washing, non-oxidative desulfurization, and drying to obtain durable antibacterial regenerated cellulose fibers; the amount of functional microcapsules used is 9% of the type A cellulose content in the spinning solution; the concentration of sulfuric acid in the coagulation bath is 120 g / L, the concentration of sodium sulfate is 350 g / L, and the concentration of zinc sulfate is 14 g / L.

[0047] Test Example 1

[0048] Based on Example 1, the prepared functional microcapsules were characterized using scanning electron microscopy, and the results were as follows: Figure 1 As shown. Figure 1 It can be seen that the functional microcapsules are mainly spherical and the particle size distribution is relatively uniform, indicating that the functional microcapsules were successfully prepared.

[0049] Test Example 2

[0050] The properties of the modified regenerated cellulose fibers of Examples 1-3 and Comparative Examples 1-2 were tested.

[0051] The antibacterial properties of antibacterial regenerated cellulose fiber were tested with reference to GB / T 20944.3-2008 “Evaluation of antibacterial properties of textiles Part 3: Oscillation method”.

[0052] The strength of antibacterial regenerated cellulose fiber was tested with reference to GB / T 14337-2022 “Test method for tensile properties of chemical staple fibers”.

[0053] Wash according to AATCC-61-2013 "Color Fastness to Washing: Accelerated".

[0054] Figure 2 The antibacterial performance test diagram of the unmodified regenerated cellulose fiber of Comparative Example 1 and the antibacterial regenerated cellulose fiber of Example 1 is as follows:

[0055] Table 1 shows the relevant performance parameters finally measured:

[0056] Table 1

[0057]

[0058]

[0059] From Table 1 and Figure 2 It can be seen that the unmodified regenerated cellulose fiber has an inhibition rate of 0% against Escherichia coli and Staphylococcus aureus, indicating its poor antibacterial properties. The regenerated cellulose fiber modified with functional microcapsules has an inhibition rate of over 96.5% against Escherichia coli and Staphylococcus aureus, and the inhibition rate remains above 80% after 50 washes, indicating that the antibacterial regenerated cellulose fiber has excellent antibacterial properties and water-washing resistance. In addition, the dry breaking strength and wet breaking strength of the modified regenerated cellulose fiber decrease slightly, indicating that the functional microcapsules are highly compatible with the regenerated cellulose fiber and have little effect on the strength properties of the regenerated cellulose fiber. Compared with Comparative Example 2, microcapsules cannot be formed without the addition of chitosan, and the antibacterial and sustained-release properties of the modified regenerated cellulose fiber are reduced. This is also because the Schiff base structure cannot be formed, and a synergistic antibacterial effect cannot be formed with the wormwood essential oil. In addition, after 50 washes, the antibacterial rates of the modified regenerated cellulose fiber against Escherichia coli and Staphylococcus aureus are reduced to 68.8% and 65.1%, respectively, indicating that its durability is poor. This is because the microcapsules cannot be formed, resulting in a high volatilization and loss rate of the wormwood essential oil.

[0060] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for preparing durable antibacterial regenerated cellulose fiber, characterized in that: The following steps are included: S1. Adding wormwood essential oil and chitosan solution to oxidized sodium alginate solution in sequence, reacting at a pH of 6-7, filtering and drying to obtain functional microcapsules with wormwood essential oil as a core material and chitosan and oxidized sodium alginate as wall materials; the mass ratio of chitosan to oxidized sodium alginate is 1-2:1; the mass fraction of the chitosan solution is 0.75%-1.25%, the pH of the chitosan solution is 4-5, and the pH regulator is acetic acid and / or citric acid; the mass fraction of the oxidized sodium alginate solution is 0.5%-2.0%; the reaction temperature is 60°C-80°C, and the reaction time is 40min-70min; S2. The functional microcapsules described in S1 are blended with a spinning solution, and the durable antibacterial regenerated cellulose fibers are obtained by wet spinning, coagulation molding, washing, non-oxidative desulfurization and drying; the spinning solution is a mixture of methyl cellulose and sodium hydroxide.

2. The method for preparing the durable antibacterial regenerated cellulose fiber according to claim 1, characterized in that: In S1, the diameter of the functional microcapsules is 1.5 μm-3 μm, the mass ratio of the core material to the wall material is 1:2-3, and the encapsulation rate of the wormwood essential oil is 63%-68%.

3. The method for preparing durable antibacterial regenerated cellulose fiber according to claim 1, characterized in that: In S1, the pH regulator is sodium hydroxide.

4. The method for preparing durable antibacterial regenerated cellulose fiber according to claim 1, characterized in that: In S2, the mass fraction of cellulose methyl ester in the spinning solution is 6%-9%, and the mass fraction of sodium hydroxide is 8%-12%; the amount of the functional microcapsules used is 7%-9% of the cellulose methyl ester content in the spinning solution.

5. The method for preparing durable antibacterial regenerated cellulose fiber according to claim 1, characterized in that: In S2, the spinning speed of the wet spinning is 30 m / min-50 m / min, and the total draft is 120%-130%.

6. The method for preparing durable antibacterial regenerated cellulose fiber according to claim 1, characterized in that: In S2, the coagulation molding is carried out in a coagulation bath, the temperature of the coagulation bath is 35°C-45°C; the concentration of sulfuric acid in the coagulation bath is 80g / L-120g / L, the concentration of sodium sulfate is 280g / L-350g / L, and the concentration of zinc sulfate is 10g / L-14g / L.

7. The durable antibacterial regenerated cellulose fiber prepared by the method according to any one of claims 1 to 6.

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