A method for preparing a chlorophyll-modified regenerated cellulose fiber

Abstract

The present application belongs to the technical field of regenerated cellulose fibers, and particularly relates to a preparation method of chlorophyll modified regenerated cellulose fibers. The present application uses modified aerogel to load chlorophyll, greatly reduces the loss of chlorophyll in the fiber preparation process and subsequent washing process, improves the functional durability of the fiber, and avoids the influence of chlorophyll aggregation in the spinning dope on the mechanical properties of the fiber. The chlorophyll modified regenerated cellulose fiber prepared by the present application is light green in color, has good antibacterial effect while having natural dyeing effect, and the detection shows that the antibacterial rates of the fiber to Staphylococcus aureus, Escherichia coli and Candida albicans are all above 95% after 50 times of washing; the fiber has deodorizing effect, and the removal rates of the fiber to ammonia, acetic acid and iso-valeric acid are all above 90%, the fiber is safe and environmentally friendly, and can be used in various fields such as home textiles, underwear and home clothes.

Description

Technical Field

[0001] This invention belongs to the field of regenerated cellulose fiber technology, specifically relating to a method for preparing chlorophyll-modified regenerated cellulose fiber. Background Technology

[0002] Chlorophyll, a natural pigment found in plants, possesses environmentally friendly properties such as biodegradability and non-toxic residue. Its application in functional textiles can reduce environmental pollution during production and use, aligning with the trend of green and sustainable development. Furthermore, chlorophyll's multifunctionality significantly enhances the added value of textiles: 1) the porphyrin ring in its molecular structure can disrupt bacterial cell membranes, endowing fabrics with antibacterial properties; 2) it effectively removes odor molecules through chemical adsorption or decomposition, enhancing deodorization; in addition, its natural UV absorption capacity and antioxidant properties can improve the fabric's UV resistance and anti-aging properties.

[0003] Regenerated cellulose fibers, made from natural cellulose, possess excellent moisture absorption, breathability, and a soft touch. They primarily include modal, viscose, and lyocell fibers. Combining chlorophyll with regenerated cellulose fibers not only preserves the fibers' superior properties but also expands their functional applications, providing a new direction for developing novel green and multifunctional textile materials.

[0004] CN115611907A, "A Textile Fiber Modified with Chlorophyll Extract," describes a chlorophyll derivative obtained by reacting chlorophyll with tert-butyl acetate-tetraethylene glycol protected by a tert-butyl group. This derivative can be chemically bonded to regenerated cellulose fibers. The modified fiber prepared by this method exhibits good wash resistance, the chlorophyll derivative is not easily removed by washing, and it also possesses antistatic properties and antibacterial activity.

[0005] CN111851066A, "A Method for Preparing Chlorophyll Fiber," describes a method where chlorophyll extract powder is first mixed with water, a dispersant, and an alkali to form a chlorophyll solution. Then, regenerated cellulose fiber is reacted with water, a cationic modifier, and an alkali to produce cationic fiber. Finally, the two are mixed, allowing the chlorophyll to be adsorbed onto the fiber. The resulting fiber has a natural green color, a bright and soft luster, good moisture absorption and release, antibacterial properties, and deodorizing characteristics. Furthermore, the chlorophyll is durable, washable, and does not fade.

[0006] However, the aforementioned existing technologies have the following drawbacks:

[0007] 1. Complex process and high cost: It involves the synthesis of chlorophyll derivatives or multiple chemical reactions, and the reaction conditions are strictly required, which is not conducive to large-scale industrial production.

[0008] 2. Poor fiber performance stability: The binding effect of chlorophyll and regenerated cellulose fiber may be affected by a variety of factors, such as reaction temperature, time, and reagent dosage. If not properly controlled, the chlorophyll loading will be unstable, which will affect the antibacterial and UV-resistant properties of the fiber, and may also reduce the mechanical properties of the fiber, causing its strength, elongation and other indicators to fail to meet the standards.

[0009] 3. Chlorophyll stability issues: Chlorophyll is easily decomposed by factors such as light, temperature, and pH. Existing technologies cannot completely prevent its degradation, thus affecting the final functional properties and color stability of the fiber. Summary of the Invention

[0010] To address the problems existing in the prior art, this invention proposes a method for preparing chlorophyll-modified regenerated cellulose fibers, thereby achieving the invention objective of improving the stability of chlorophyll in fibers and satisfying the functional and mechanical properties of the fibers.

[0011] A method for preparing chlorophyll-modified regenerated cellulose fiber includes the following steps:

[0012] S1. Preparation of modified aerogel

[0013] A precursor solution was prepared by mixing tetraethyl orthosilicate, vinyltriethoxysilane, ethanol, and deionized water. The pH was then adjusted to 3–4 with 1–1.5 mol / L hydrochloric acid. Polyethylene glycol diacrylate, potassium persulfate initiator, and isobornyl acrylate molecular weight regulator were then added and stirred for 20–30 min. The mixture was then reacted in a constant temperature water bath at 60–70 °C for 2–3 h. After the reaction was completed, the mixture was cooled to room temperature. Ammonia solution with a concentration of 1–2 mol / L was added to adjust the pH to 7–8 and stirred for 15–20 min until gelation was achieved. An equal volume of ethanol solution was added at room temperature and the mixture was aged for 12–15 h. After aging, ethanol and n-hexane were replaced sequentially, and the modified aerogel modified by crosslinking polymerization of polyethylene glycol diacrylate was obtained using the supercritical CO2 drying method.

[0014] Preferably, the molar ratio of tetraethyl orthosilicate, vinyltriethoxysilane, ethanol and deionized water is 1:0.2-0.3:8-12:4-6.

[0015] Preferably, the polyethylene glycol diacrylate has a molecular weight of 400 and is added in an amount of 13-18% of the mass of tetraethyl orthosilicate.

[0016] Preferably, the amount of potassium persulfate added is 1 to 1.6% of the mass of polyethylene glycol diacrylate.

[0017] Preferably, the amount of the molecular weight regulator isoborneol acrylate added is 0.2 to 0.4% of the mass of polyethylene glycol diacrylate.

[0018] Preferably, the volume fraction of ethanol in the ethanol solution is 80-95%, and the remainder is deionized water.

[0019] Preferably, the modified aerogel has a pore size of 20–30 nm and a specific surface area of ​​518–624 m². 2 / g, porosity greater than 80%.

[0020] S2, adsorption

[0021] Chlorophyll was added to anhydrous ethanol and stirred until dissolved. Then, modified aerogel was added and stirred for 10–20 min. After standing for 4–6 h, the modified aerogel adsorbed the chlorophyll. After drying, the composite modified aerogel was obtained.

[0022] Preferably, the mass ratio of chlorophyll to anhydrous ethanol is 1:5 to 6.

[0023] Preferably, the mass ratio of chlorophyll to the composite modified aerogel is 1:2 to 3.

[0024] S3, Preparation of Dispersion

[0025] The composite modified aerogel and hydroxypropyl methylcellulose were added to deionized water and stirred for 20-30 minutes to obtain a composite modified aerogel dispersion with good dispersibility (D90 < 2 μm).

[0026] Preferably, the mass ratio of the composite modified aerogel, hydroxypropyl methylcellulose, and deionized water is 7–9:0.5–1:50–60.

[0027] The addition of hydroxypropyl methylcellulose can further improve the stability of the dispersion.

[0028] S4. Preparation of spinning solution

[0029] The pulp raw material is soaked, pressed, crushed, aged, yellowed, dissolved, filtered, defoamed, and matured to obtain spinning dope.

[0030] Preferably, the pulp raw material is one or more of wood pulp, cotton pulp, or bamboo pulp.

[0031] Preferably, the immersion temperature is 50-60°C and the time is 50-60 minutes, and the solution is immersed in a sodium hydroxide solution with a mass fraction of 14-18%.

[0032] Preferably, the aging temperature is 20-25°C and the aging time is 1.5-2 hours.

[0033] Preferably, the chlorosis temperature is 15-20°C and the chlorosis time is 40-60 min.

[0034] Preferably, the maturation time is 12-24 hours and the maturation temperature is 15-20°C.

[0035] Preferably, the viscosity of the spinning solution is controlled at 50-70s (falling ball method), the degree of maturity is controlled at 11-16mL (10% NH4Cl), the NaOH content is 4.2-5.1wt%, and the cellulose content is 7.3-8.5wt%.

[0036] S5, blending

[0037] The composite modified aerogel dispersion was added to the spinning solution and stirred for 3-5 minutes to obtain the blended spinning solution.

[0038] Preferably, the amount of the composite modified aerogel dispersion added is calculated as 4 to 6 wt% of the composite modified aerogel in the composite modified aerogel dispersion as a percentage of the cellulose content.

[0039] S6, spinning and forming

[0040] The blended spinning solution is ejected through a spinneret and then formed and drawn in a coagulation bath to obtain nascent fiber bundles; the nascent fiber bundles are further formed in a second bath to obtain fiber bundles.

[0041] Preferably, in the coagulation bath components, the sulfuric acid is 80-100 g / L, the zinc sulfate is 50-70 g / L, the sodium sulfate is 210-240 g / L, the reaction temperature is 40-45℃, the spinning rate is 30-40 m / min, and the draw is 10-30%.

[0042] Preferably, in the second bath, the concentration of sulfuric acid is 20-30 g / L, the temperature is 70-90°C, the draw ratio in the second bath is 70-90%, and the spinning rate is 30-40 m / min.

[0043] S7, Post-processing

[0044] The fiber bundles are acid-washed, desulfurized, washed, oiled, and dried to obtain chlorophyll-modified regenerated cellulose fibers.

[0045] Conventional silica aerogels tend to agglomerate in spinning solutions, which can easily affect fiber properties. Therefore, this invention adds polyethylene glycol diacrylate during the formation of silica aerogels and crosslinks and copolymerizes them under the action of an initiator to obtain modified aerogels. This not only improves the brittleness of silica aerogels but also enhances their dispersibility in spinning solutions, preventing the agglomeration of small particles. The participation of a molecular weight regulator during the crosslinking and copolymerization process prevents the crosslinked copolymer from having an excessively large molecular weight, which would reduce porosity.

[0046] Chlorophyll is soluble in ethanol but insoluble in water. Chlorophyll is dissolved in ethanol and then adsorbed using a modified aerogel, thus loading the chlorophyll into the micropores of the modified aerogel. Because the coagulation bath is acidic, the stability of chlorophyll is easily affected by the acidic environment. Therefore, another function of using polyethylene glycol diacrylate (PEG) modification is that when the modified aerogel is in alcohol, the micropores can normally adsorb and load chlorophyll. However, under the action of deionized water in the dispersion, the PEG diacrylate cross-linked copolymer in the modified aerogel expands into a gel-like state, blocking the micropores of the modified aerogel. This prevents any unstable factors from external high temperature or acid / alkali environment that could cause chlorophyll degradation or discoloration, affecting the functionality and color of the fiber. After drying, the PEG diacrylate cross-linked copolymer in the modified aerogel becomes thinner, and the micropores are exposed again to release functional substances. Similarly, during the subsequent washing process, the PEG diacrylate cross-linked copolymer in the modified aerogel expands into a gel-like state, blocking the micropores of the modified aerogel, reducing chlorophyll loss during washing, and greatly improving the slow-release effect of chlorophyll.

[0047] Since the cross-linked copolymer of polyethylene glycol diacrylate absorbs water and forms a gel, the amount of polyethylene glycol diacrylate added must be moderate. Too little will result in incomplete clogging, while too much will cause the aerogel to expand in volume and risk cracking or deformation. Therefore, the preferred amount of polyethylene glycol diacrylate added is 13 to 18% of the mass of tetraethyl orthosilicate.

[0048] By adopting the above technical solution, the technical effect achieved by the present invention is as follows:

[0049] 1. The chlorophyll-modified regenerated cellulose fiber prepared by this invention has excellent mechanical properties, with a dry breaking strength of 2.52-2.7 cN / dtex and a wet breaking strength of 1.47-1.56 cN / dtex.

[0050] 2. The chlorophyll-modified regenerated cellulose fiber prepared by this invention is light green in color. While possessing a natural dyeing effect, it also exhibits excellent antibacterial properties. After 50 washes, the inhibition rate against Staphylococcus aureus, Escherichia coli, and Candida albicans is all above 95% (as determined according to GB / T 20944.3-2008). It also has a deodorizing effect, with a removal rate of over 90% for ammonia, acetic acid, and isovaleric acid (as determined according to GB / T 33610.3-2019). The fiber is safe and environmentally friendly and can be used in various fields such as home textiles, underwear, and loungewear.

[0051] 3. The chlorophyll-modified regenerated cellulose fiber prepared by this invention has good anti-ultraviolet and antioxidant effects, wherein the ultraviolet protection factor (UPF) is greater than 50. AV>2000 (determined according to GB / T 18830-2009); free radical scavenging rate greater than 95% (determined according to T / CCTA 20102-2023 ABTS method).

[0052] 4. This invention utilizes modified aerogel to load chlorophyll, which greatly reduces the loss of chlorophyll during fiber preparation and subsequent washing, and improves the functionality and durability of the fiber; the composite modified aerogel can be used for various regenerated cellulose fibers, including viscose fiber, lyocell fiber, and modal fiber. Attached Figure Description

[0053] Figure 1 The color of the chlorophyll-modified regenerated cellulose fiber prepared in Example 1. Detailed Implementation

[0054] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structure, features and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0055] Example 1: A method for preparing chlorophyll-modified regenerated cellulose fiber, comprising the following steps:

[0056] S1. Preparation of modified aerogel

[0057] A precursor solution was prepared by mixing tetraethyl orthosilicate, vinyltriethoxysilane, ethanol, and deionized water. The pH was then adjusted to 3 with 1 mol / L hydrochloric acid. Polyethylene glycol diacrylate, potassium persulfate initiator, and isobornyl acrylate molecular weight regulator were then added and stirred for 30 min. The mixture was then reacted in a constant temperature water bath at 65°C for 2.5 h. After the reaction was completed, the mixture was cooled to room temperature. Ammonia solution with a concentration of 1 mol / L was added to adjust the pH to 7.5 and stirred for 18 min until gelation was achieved. An equal volume of ethanol solution was added at room temperature and the mixture was aged for 14 h. After aging, ethanol and n-hexane were replaced sequentially. The modified aerogel modified by crosslinking polymerization of polyethylene glycol diacrylate was obtained by supercritical CO2 drying.

[0058] The molar ratio of tetraethyl orthosilicate, vinyltriethoxysilane, ethanol and deionized water is 1:0.25:10:5.

[0059] The polyethylene glycol diacrylate has a molecular weight of 400 and is added in an amount that is 15% of the mass of tetraethyl orthosilicate.

[0060] The amount of potassium persulfate added is 1.4% of the mass of polyethylene glycol diacrylate.

[0061] The molecular weight regulator, isoborneol acrylate, is added at an amount of 0.3% of the mass of polyethylene glycol diacrylate.

[0062] The ethanol solution contains 85% ethanol by volume, with the remainder being deionized water.

[0063] The modified aerogel has a pore size range of 20–30 nm and a specific surface area of ​​593 m². 2 / g, with a porosity of 84%.

[0064] S2, adsorption

[0065] Chlorophyll was added to anhydrous ethanol and stirred until dissolved. Then, modified aerogel was added and stirred for 15 minutes. After standing for 5 hours, the modified aerogel adsorbed the chlorophyll. After drying, the composite modified aerogel was obtained.

[0066] The mass ratio of chlorophyll to anhydrous ethanol is 1:5.5.

[0067] The mass ratio of chlorophyll to the composite modified aerogel is 1:2.5.

[0068] S3, Preparation of Dispersion

[0069] The composite modified aerogel and hydroxypropyl methylcellulose were added to deionized water and stirred for 25 min to obtain a composite modified aerogel dispersion with good dispersibility (D90 < 2 μm).

[0070] The mass ratio of the composite modified aerogel, hydroxypropyl methylcellulose, and deionized water is 8:0.7:55.

[0071] S4. Preparation of spinning solution

[0072] Cotton pulp is soaked, pressed, crushed, aged, yellowed, dissolved, filtered, defoamed, and matured to obtain spinning solution.

[0073] The immersion temperature was 55°C and the time was 60 minutes, and the solution was immersed in a 16% sodium hydroxide solution.

[0074] The aging temperature was 23℃ and the aging time was 2 hours.

[0075] The chlorosis temperature was 20℃ and the chlorosis time was 50 min.

[0076] The maturation time is 16 hours and the maturation temperature is 20°C.

[0077] The viscosity of the spinning solution is controlled at 60s (falling ball method), the maturity is controlled at 14mL (10% NH4Cl), the NaOH content is 4.7wt%, and the methyl cellulose content is 8wt%.

[0078] S5, blending

[0079] The composite modified aerogel dispersion was added to the spinning solution and stirred for 4 minutes to obtain the blended spinning solution.

[0080] The amount of the composite modified aerogel dispersion added is calculated as 5 wt% of the composite modified aerogel in the aerogel dispersion, which accounts for 5 wt% of the cellulose content.

[0081] S6, spinning and forming

[0082] The blended spinning solution is ejected through a spinneret and then formed and drawn in a coagulation bath to obtain nascent fiber bundles; the nascent fiber bundles are further formed in a second bath to obtain fiber bundles.

[0083] The coagulation bath composition includes 90 g / L sulfuric acid, 60 g / L zinc sulfate, and 220 g / L sodium sulfate. The reaction temperature is 43°C, the spinning rate is 35 m / min, and the draw is 20%.

[0084] In the second bath, the concentration of sulfuric acid is 25 g / L, the temperature is 80°C, the draw ratio is 80%, and the spinning rate is 35 m / min.

[0085] S7, Post-processing

[0086] The fiber bundles are acid-washed, desulfurized, washed, oiled, and dried to obtain chlorophyll-modified regenerated cellulose fibers.

[0087] Example 2: A method for preparing chlorophyll-modified regenerated cellulose fiber, comprising the following steps:

[0088] S1. Preparation of modified aerogel

[0089] A precursor solution was prepared by mixing tetraethyl orthosilicate, vinyltriethoxysilane, ethanol, and deionized water. The pH was then adjusted to 4 with 1.5 mol / L hydrochloric acid. Polyethylene glycol diacrylate, potassium persulfate initiator, and isobornyl acrylate molecular weight regulator were then added and stirred for 20 min. The mixture was then reacted in a constant temperature water bath at 60℃ for 2 h. After the reaction was completed, the mixture was cooled to room temperature. Ammonia solution with a concentration of 1 mol / L was added to adjust the pH to 7 and stirred for 20 min until gelation was achieved. An equal volume of ethanol solution was added at room temperature and the mixture was aged for 12 h. After aging, ethanol and n-hexane were replaced sequentially. The modified aerogel modified by crosslinking polymerization of polyethylene glycol diacrylate was obtained by supercritical CO2 drying.

[0090] The molar ratio of tetraethyl orthosilicate, vinyltriethoxysilane, ethanol and deionized water is 1:0.2:8:4.

[0091] The polyethylene glycol diacrylate has a molecular weight of 400 and is added in an amount that is 13% of the mass of tetraethyl orthosilicate.

[0092] The amount of potassium persulfate added is 1% of the mass of polyethylene glycol diacrylate.

[0093] The amount of the molecular weight regulator isoborneol acrylate added is 0.2% of the mass of polyethylene glycol diacrylate.

[0094] The ethanol solution contains 80% ethanol by volume, with the remainder being deionized water.

[0095] The modified aerogel has a pore size range of 20–30 nm and a specific surface area of ​​624 m². 2 / g, with a porosity of 85%.

[0096] S2, adsorption

[0097] Chlorophyll was added to anhydrous ethanol and stirred until dissolved. Then, modified aerogel was added and stirred for 20 minutes. After standing for 6 hours, the modified aerogel adsorbed the chlorophyll. After drying, the composite modified aerogel was obtained.

[0098] The mass ratio of chlorophyll to anhydrous ethanol is 1:6.

[0099] The mass ratio of chlorophyll to the composite modified aerogel is 1:3.

[0100] S3, Preparation of Dispersion

[0101] The composite modified aerogel and hydroxypropyl methylcellulose were added to deionized water and stirred for 30 min to obtain a composite modified aerogel dispersion with good dispersibility (D90 < 2 μm).

[0102] The mass ratio of the composite modified aerogel, hydroxypropyl methylcellulose, and deionized water is 7:0.5:50.

[0103] S4. Preparation of spinning solution

[0104] Cotton pulp is soaked, pressed, crushed, aged, yellowed, dissolved, filtered, defoamed, and matured to obtain spinning solution.

[0105] The immersion temperature was 50°C and the time was 50 minutes, and the solution was immersed in a 14% sodium hydroxide solution.

[0106] The aging temperature is 20℃ and the aging time is 1.5h.

[0107] The chlorosis temperature was 15℃ and the chlorosis time was 40 min.

[0108] The maturation time is 12 hours and the maturation temperature is 15°C.

[0109] The viscosity of the spinning solution is controlled at 50s (falling ball method), the maturity is controlled at 11mL (10% NH4Cl), the NaOH content is 4.2wt%, and the cellulose content is 7.3wt%.

[0110] S5, blending

[0111] The composite modified aerogel dispersion was added to the spinning solution and stirred for 3 minutes to obtain the blended spinning solution.

[0112] The amount of the composite modified aerogel dispersion added is calculated as 4 wt% of the composite modified aerogel in the cellulose fiber content.

[0113] S6, spinning and forming

[0114] The blended spinning solution is ejected through a spinneret and then formed and drawn in a coagulation bath to obtain nascent fiber bundles; the nascent fiber bundles are further formed in a second bath to obtain fiber bundles.

[0115] The coagulation bath composition includes 80 g / L sulfuric acid, 50 g / L zinc sulfate, and 210 g / L sodium sulfate. The reaction temperature is 40°C, the spinning rate is 30 m / min, and the draw is 10%.

[0116] In the second bath, the concentration of sulfuric acid is 20 g / L, the temperature is 70 °C, the draw ratio is 90%, and the spinning rate is 30 m / min.

[0117] S7, Post-processing

[0118] The fiber bundles are acid-washed, desulfurized, washed, oiled, and dried to obtain chlorophyll-modified regenerated cellulose fibers.

[0119] Example 3: A method for preparing chlorophyll-modified regenerated cellulose fiber, comprising the following steps:

[0120] S1. Preparation of modified aerogel

[0121] A precursor solution was prepared by mixing tetraethyl orthosilicate, vinyltriethoxysilane, ethanol, and deionized water. The pH was then adjusted to 3.5 with 1 mol / L hydrochloric acid. Polyethylene glycol diacrylate, potassium persulfate initiator, and isobornyl acrylate molecular weight regulator were then added and stirred for 30 min. The mixture was then reacted in a constant temperature water bath at 70℃ for 3 h. After the reaction was completed, the mixture was cooled to room temperature. Ammonia solution with a concentration of 2 mol / L was added to adjust the pH to 8 and stirred for 20 min until gelation was achieved. An equal volume of ethanol solution was added at room temperature and the mixture was aged for 15 h. After aging, ethanol and n-hexane were replaced sequentially. The modified aerogel modified by crosslinking polymerization of polyethylene glycol diacrylate was obtained by supercritical CO2 drying.

[0122] The molar ratio of tetraethyl orthosilicate, vinyltriethoxysilane, ethanol and deionized water is 1:0.3:12:6.

[0123] The polyethylene glycol diacrylate has a molecular weight of 400 and is added in an amount that is 18% of the mass of tetraethyl orthosilicate.

[0124] The amount of potassium persulfate added is 1.6% of the mass of polyethylene glycol diacrylate.

[0125] The amount of the molecular weight regulator isoborneol acrylate added is 0.4% of the mass of polyethylene glycol diacrylate.

[0126] The ethanol solution contains 95% ethanol by volume, with the remainder being deionized water.

[0127] The modified aerogel has a pore size range of 20–30 nm and a specific surface area of ​​518 m². 2 / g, with a porosity of 81%.

[0128] S2, adsorption

[0129] Chlorophyll was added to anhydrous ethanol and stirred until dissolved. Then, modified aerogel was added and stirred for 20 minutes. After standing for 6 hours, the modified aerogel adsorbed the chlorophyll. After drying, the composite modified aerogel was obtained.

[0130] The mass ratio of chlorophyll to anhydrous ethanol is 1:5.

[0131] The mass ratio of chlorophyll to the composite modified aerogel is 1:2.

[0132] S3, Preparation of Dispersion

[0133] The composite modified aerogel and hydroxypropyl methylcellulose were added to deionized water and stirred for 30 min to obtain a composite modified aerogel dispersion with good dispersibility (D90 < 2 μm).

[0134] The mass ratio of the composite modified aerogel, hydroxypropyl methylcellulose, and deionized water is 9:1:60.

[0135] S4. Preparation of spinning solution

[0136] Cotton pulp is soaked, pressed, crushed, aged, yellowed, dissolved, filtered, defoamed, and matured to obtain spinning solution.

[0137] The immersion temperature was 60°C and the time was 60 minutes, and the solution was immersed in a sodium hydroxide solution with a mass fraction of 18%.

[0138] The aging temperature is 25℃ and the aging time is 2 hours.

[0139] The chlorosis temperature was 20℃ and the chlorosis time was 60 min.

[0140] The maturation time is 24 hours and the maturation temperature is 20°C.

[0141] The viscosity of the spinning solution is controlled at 70s (falling ball method), the maturity is controlled at 16mL (10% NH4Cl), the NaOH content is 5.1wt%, and the methyl cellulose content is 8.5wt%.

[0142] S5, blending

[0143] The composite modified aerogel dispersion was added to the spinning solution and stirred for 5 minutes to obtain the blended spinning solution.

[0144] The amount of the composite modified aerogel dispersion added is calculated as 6 wt% of the composite modified aerogel in the aerogel dispersion, which accounts for 6 wt% of the cellulose content.

[0145] S6, spinning and forming

[0146] The blended spinning solution is ejected through a spinneret and then formed and drawn in a coagulation bath to obtain nascent fiber bundles; the nascent fiber bundles are further formed in a second bath to obtain fiber bundles.

[0147] The coagulation bath composition includes 100 g / L sulfuric acid, 70 g / L zinc sulfate, and 240 g / L sodium sulfate. The reaction temperature is 45°C, the spinning rate is 40 m / min, and the draw is 30%.

[0148] In the second bath, the concentration of sulfuric acid is 30 g / L, the temperature is 90 °C, the draw ratio is 70%, and the spinning rate is 40 m / min.

[0149] S7, Post-processing

[0150] The fiber bundles are acid-washed, desulfurized, washed, oiled, and dried to obtain chlorophyll-modified regenerated cellulose fibers.

[0151] Comparative Example 1: A representative example, Example 1, was selected. The modified aerogel was removed, and an equal amount of chlorophyll was directly added to the spinning solution as a dispersion. All other aspects were the same as in Example 1. This was used as Comparative Example 1.

[0152] Comparative Example 2: A representative example, Example 1, was selected. The polyethylene glycol diacrylate, potassium persulfate initiator, and isobornyl acrylate molecular weight regulator in step S1 of Example 1 were removed. All other components were the same as in Example 1. This was used as Comparative Example 2.

[0153] Comparative Example 3: A representative example, Example 1, was selected. The molecular weight regulator isoborneol acrylate in step S1 of Example 1 was removed, and the rest was the same as Example 1. This was used as Comparative Example 3.

[0154] The chlorophyll-modified regenerated cellulose fibers prepared in Examples 1-3 exhibited good antibacterial effects, with inhibition rates of over 95% against Staphylococcus aureus, Escherichia coli, and Candida albicans after fifty washes. They also demonstrated deodorizing effects, removing over 90% of ammonia, acetic acid, and isovaleric acid. Furthermore, they possessed excellent UV protection and antioxidant properties, with a UV protection factor (UPF) > 50. AV >2000; Free radical scavenging rate greater than 95%.

[0155] The fibers prepared in Examples 1-3 and Comparative Examples 1-2 were tested for mechanical properties and loss rate, as detailed in Table 1.

[0156] Table 1

[0157]

[0158] As can be seen from Table 1, the chlorophyll-modified regenerated cellulose fibers prepared using Examples 1-3 not only exhibit excellent mechanical properties but also demonstrate stable chlorophyll properties, good fiber color effects, and preservation of the natural color of chlorophyll (see Table 1). Figure 1 ).

[0159] In Comparative Example 1, an equal amount of chlorophyll was directly prepared into a dispersion and added to the spinning solution. This not only resulted in significant chlorophyll loss and high costs during fiber preparation, but also led to poor binding between chlorophyll and fiber, causing easy aggregation in the spinning solution and a substantial reduction in fiber mechanical properties.

[0160] Comparative Example 2, which removed polyethylene glycol diacrylate, potassium persulfate initiator, and isoborneol acrylate molecular weight regulator from step S1 of Example 1, produced silica aerogel with poor dispersion and easy aggregation, resulting in decreased fiber strength. Furthermore, due to the loss of the micropore-blocking effect of the polyethylene glycol diacrylate crosslinking copolymer, some of these components were lost during the preparation process and subsequent water washing.

[0161] Comparative Example 3, by removing the molecular weight regulator isoborneol acrylate from step S1 of Example 1, produced aerogel particles that were not uniform, with a significantly reduced porosity of only 48% and a specific surface area of ​​313 m². 2 / g, which seriously affects the adsorption of chlorophyll.

[0162] Furthermore, due to the degradation of chlorophyll in Comparative Examples 1 and 2, the color of the fibers became darker compared to Example 1.

[0163] Unless otherwise specified, all proportions and percentages mentioned in this invention are mass proportions and mass percentages; all raw materials are commercially available.

[0164] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing chlorophyll-modified regenerated cellulose fiber, characterized in that, The preparation method includes the preparation of modified aerogel, adsorption, preparation of dispersion, preparation of spinning solution, blending, spinning and shaping and post-treatment. The modified aerogel is prepared by preparing a precursor solution of tetraethyl orthosilicate, vinyltriethoxysilane, ethanol and deionized water, adjusting the pH to 3-4 with hydrochloric acid at a concentration of 1-1.5 mol / L, adding polyethylene glycol diacrylate, potassium persulfate as an initiator and isobornyl acrylate as a molecular weight regulator, mixing and stirring for 20-30 min, reacting in a constant temperature water bath at 60-70℃ for 2-3 h, cooling to room temperature after the reaction, adding ammonia water at a concentration of 1-2 mol / L to adjust the pH to 7-8 and stirring for 15-20 min to wait for gelation, adding an equal volume of ethanol solution at room temperature and aging for 12-15 h, and then replacing with ethanol and n-hexane successively, using CO2 supercritical drying method to obtain the modified aerogel modified by crosslinking polymerization of polyethylene glycol diacrylate. The polyethylene glycol diacrylate has a molecular weight of 400 and is added in an amount of 13-18% of the mass of tetraethyl orthosilicate. The adsorption process involves adding chlorophyll to anhydrous ethanol and stirring until dissolved, then adding modified aerogel and stirring for 10–20 min, allowing it to stand for 4–6 h, where the modified aerogel adsorbs the chlorophyll, and drying to obtain a composite modified aerogel. The dispersion was prepared by adding the composite modified aerogel and hydroxypropyl methylcellulose to deionized water and stirring for 20-30 minutes to obtain a composite modified aerogel dispersion with good dispersibility (D90 < 2 μm).

2. The method for preparing chlorophyll-modified regenerated cellulose fiber according to claim 1, characterized in that, The molar ratio of tetraethyl orthosilicate, vinyltriethoxysilane, ethanol and deionized water is 1:0.2-0.3:8-12:4-6; The amount of potassium persulfate added is 1 to 1.6% of the mass of polyethylene glycol diacrylate; The amount of the molecular weight regulator isoborneol acrylate added is 0.2-0.4% of the mass of polyethylene glycol diacrylate; The ethanol solution contains 80-95% ethanol by volume, with the remainder being deionized water.

3. The method for preparing chlorophyll-modified regenerated cellulose fiber according to claim 1, characterized in that, The mass ratio of chlorophyll to anhydrous ethanol is 1:5-6; The mass ratio of chlorophyll to the composite modified aerogel is 1:2 to 3.

4. The method for preparing chlorophyll-modified regenerated cellulose fiber according to claim 1, characterized in that, The mass ratio of the composite modified aerogel, hydroxypropyl methylcellulose, and deionized water is 7–9:0.5–1:50–60.

5. The method for preparing chlorophyll-modified regenerated cellulose fiber according to claim 1, characterized in that, The spinning solution is prepared by impregnating, pressing, crushing, aging, xanthating, dissolving, filtering, degassing, and maturing pulp raw materials to obtain the spinning solution.

6. The method for preparing chlorophyll-modified regenerated cellulose fiber according to claim 1, characterized in that, The blending process involves adding the composite modified aerogel dispersion to the spinning solution and stirring for 3-5 minutes to obtain the blended spinning solution. The amount of the composite modified aerogel dispersion added is calculated as 4-6 wt% of the composite modified aerogel in the aerogel dispersion, which accounts for 4-6 wt% of the cellulose content.

7. The method for preparing chlorophyll-modified regenerated cellulose fiber according to claim 1, characterized in that, The spinning process involves the following steps: the blended spinning solution is sprayed out through a spinneret and then formed and drawn in a coagulation bath to obtain nascent fiber bundles; the nascent fiber bundles are further formed in a second bath to obtain fiber bundles. The coagulation bath composition includes sulfuric acid at 80–100 g / L, zinc sulfate at 50–70 g / L, and sodium sulfate at 210–240 g / L; the reaction temperature is 40–45 °C; the spinning rate is 30–40 m / min; and the draw is 10–30%. In the second bath, the concentration of sulfuric acid is 20-30 g / L, the temperature is 70-90℃, the draw ratio is 70-90%, and the spinning rate is 30-40 m / min.

8. The method for preparing chlorophyll-modified regenerated cellulose fiber according to claim 1, characterized in that, The post-processing involves acid washing, desulfurization, water washing, oiling, and drying of the fiber bundles to obtain chlorophyll-modified regenerated cellulose fibers.

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