Environment-friendly antibacterial blended yarn and preparation method thereof

Abstract

The application discloses an environment-friendly antibacterial blended yarn and a preparation method thereof. Raw materials of the blended yarn include natural plant fibers and modified modal fibers in a mass ratio of (65-70):(30-35); and the modified modal fibers are grafted with phenolic chitosan on surfaces. The natural plant fibers and the modified modal fibers are both green and environment-friendly fiber products. The natural plant fibers can provide part of antibacterial performance. The modified modal fibers have high dry and wet strength, and can compensate for the insufficient strength of the natural plant fibers. The obtained blended yarn has excellent strength and certain antibacterial property. Meanwhile, the modified modal fibers are grafted with phenolic chitosan on surfaces. The chitosan has excellent antibacterial performance, and the phenolic group can improve the poor cohesion between the natural plant fibers, so that the natural plant fibers and the modified modal fibers can be tightly combined together. The dry and wet strength and the antibacterial property of the obtained blended yarn are obviously improved.

Description

Technical Field

[0001] This application relates to the field of blended yarns, and in particular to an environmentally friendly antibacterial blended yarn and its preparation method. Background Technology

[0002] As living standards gradually improve, people have higher and higher requirements for textiles, emphasizing health, greenness, and safety. Textiles, as protective materials worn close to the body, have a loose, porous structure to meet people's demands for breathable and comfortable clothing. Due to their porous structure and hydrophilic properties, textiles can absorb sweat and oils produced by the body in daily life, but this also provides favorable conditions for bacterial growth. Bacteria multiplying on textiles can potentially harm human health through the skin, respiratory tract, and digestive tract. The proliferation of large amounts of bacteria and mold can also cause bacterial stains on the surface of textiles, affecting their appearance and quality.

[0003] Natural plant fibers, such as ulao fiber and flax fiber, are green and environmentally friendly fiber materials. They also have the ability to resist fungal erosion and parasitism. Textiles made from them have a certain degree of antibacterial properties, which can meet most of people's needs for green, environmentally friendly and antibacterial textiles. However, textiles made from natural plant fibers through spinning have low strength and poor cohesion between fibers. The fibers are prone to breakage during the spinning process. Furthermore, the pores and cavities in natural plant fibers can provide a breeding ground for anaerobic bacteria, resulting in textiles with poor antibacterial properties. Summary of the Invention

[0004] In order to obtain a green and environmentally friendly textile with excellent antibacterial properties and good mechanical properties, this application provides an environmentally friendly antibacterial blended yarn and its preparation method.

[0005] In a first aspect, this application provides an environmentally friendly antibacterial blended yarn, wherein the raw materials of the blended yarn include natural plant fibers and modified modal fibers in a mass ratio of (65-70):(30-35); the surface of the modified modal fibers is grafted with phenolic chitosan.

[0006] Preferably, the natural plant fiber includes one or a combination of several of the following: Ula grass fiber, flax fiber, bamboo fiber, lotus root fiber, and almond fiber.

[0007] More preferably, the natural plant fiber is a combination of Ula grass fiber, lotus root fiber and almond fiber.

[0008] By adopting the above technical solutions, Modal fiber is a renewable cellulose fiber whose raw materials are all natural materials. The yarn produced after blending with natural plant fibers is green and environmentally friendly. Furthermore, as a type of viscose fiber, Modal fiber has relatively higher yarn strength and evenness. Its dry strength and wet strength far exceed those of similar viscose fibers. Blending it with natural plant fibers can effectively improve its strength, resulting in yarns with excellent performance. The textiles made from this yarn are green and environmentally friendly and have good mechanical properties.

[0009] Natural plant fibers, such as Ula grass fiber, contain flavonoid antibacterial substances that have a good inhibitory effect on common bacteria. Modified modal fibers have phenolic chitosan grafted onto their surface. Chitosan itself carries a positive charge and can form an electrostatic attraction with the negatively charged substances on the surface of bacteria, thereby changing the permeability of the bacterial cell membrane, causing important substances inside the cell to be blocked, thus achieving the purpose of killing the cell. At the same time, chitosan can also inhibit the DNA transcription process inside microbial cells, preventing the cells from carrying out normal metabolism, thereby playing an antibacterial role.

[0010] Meanwhile, the modified modal fiber surface is grafted with phenolic chitosan. After phenolic modification, the chitosan can form strong hydrogen bonds with the hydroxyl radicals on the surface of the plant fiber during the blending process, so that the plant fiber and the modified modal fiber can be tightly combined. This improves the problem of poor cohesion between natural plant fibers and makes it less prone to breakage during the blending process, resulting in a significant improvement in the dry and wet strength of the blended yarn.

[0011] Preferably, the modified modal fiber is prepared according to the following method: S101. Add post-treatment modifier 1 to deionized water to prepare post-treatment solution 1 with a mass fraction of 8-12%. Adjust the pH of post-treatment solution 1 to 5-6. The bath ratio of modal fiber to post-treatment solution 1 is 1:(20-25). The treatment temperature is 50-60℃ and the treatment time is 2-3h. After washing and drying, the modal fiber after one treatment is obtained. S102. Add post-treatment modifier 2 to deionized water to prepare post-treatment solution 2 with a mass fraction of 30-40%. After one treatment, the bath ratio of modal fiber to post-treatment solution 2 is 1:(30-32), the treatment temperature is 55-60℃, the treatment time is 1-1.5h, and then the modified modal fiber is obtained after washing and drying.

[0012] Preferably, the post-treatment modifier 1 comprises an acrylic monomer and an initiator in a mass ratio of 1:(0.08-0.12); the acrylic monomer comprises one or a combination of acrylic acid, methacrylic acid, and acrylamide.

[0013] Preferably, the initiator includes one or a combination of several of benzoyl peroxide, hydrogen peroxide, and ammonium persulfate.

[0014] Preferably, the post-treatment modifier 2 comprises ethylenediamine and phenolic chitosan in a mass ratio of (2-3):(7-8).

[0015] By adopting the above technical solution, the surface of Modal fiber contains a large number of hydroxyl groups. The acrylic monomer contained in post-treatment modifier 1 can combine with the hydroxyl free radicals on the surface of Modal fiber, and then carry out a bulk polymerization reaction under the action of an initiator. Acrylic polymers are first grafted onto the surface of Modal fiber, and then modified by post-treatment modifier 2. The phenolic chitosan in the modified agent 2 can combine with the acrylic polymers. The acrylic polymers can act as a transition layer to connect the phenolic chitosans to the Modal fibers. Through the grafting modification of acrylic polymers, the surface of Modal fiber contains more active oxygen-containing groups. While increasing the surface stability of Modal fibers, the grafting rate between Modal fibers and phenolic chitosan is also improved. Meanwhile, ethylenediamine is added to the post-treatment modifier. The amino groups in ethylenediamine can simultaneously bind acrylic polymers and phenolic chitosan to Modal fibers, forming a cross-linked network structure on the surface of the Modal fibers. The cross-linked fibers not only contain highly effective antibacterial phenolic chitosan on their surface, but the cross-linked structure also enhances the strength of the Modal fibers. Together with the polar groups in phenolic chitosan, hydrogen bonds are formed between the fibers and natural plant fibers, further improving the bonding force between the blended yarns and thus enhancing the strength of the blended yarns.

[0016] Preferably, the raw materials for the phenolic chitosan include chitosan, tannic acid, and a carboxyl activator in a mass ratio of 1:(3-4):(0.2-0.4).

[0017] Preferably, the carboxyl activator is a mixture of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide in a mass ratio of 1:(1-1.2).

[0018] By adopting the above technical solution, chitosan is modified by tannic acid under the action of carboxyl activator. Tannic acid contains a large number of catechol groups. On the one hand, the large number of active oxygen-containing groups can improve the reactivity between chitosan and modal fiber and increase the grafting rate. On the other hand, the catechol groups can form strong hydrogen bonds with the hydroxyl groups on the surface of natural plant fibers, which can significantly improve the bonding force between natural plant fibers and modified modal fibers. The tight bonding between the two fibers is conducive to improving the dry and wet strength of the blended yarn, and also makes the natural plant fibers less prone to breakage during the blending process.

[0019] Preferably, the phenolic chitosan is prepared by the following method: chitosan is added to an acetic acid solution and stirred to dissolve to obtain a chitosan solution; tannic acid is added to a solvent and stirred to dissolve to obtain a tannic acid solution; the temperature of the chitosan solution is adjusted to 30-35°C, and tannic acid solution and carboxyl activator are added while stirring, and the reaction is stirred for 20-24 hours. After the reaction is completed, the chitosan is obtained by dialysis and freeze-drying.

[0020] Preferably, the mass fraction of acetic acid in the acetic acid solution is 1.5% to 2%.

[0021] Preferably, the solvent includes one or a combination of methanol, ethanol, and acetone.

[0022] By adopting the above technical solution, under the action of carboxyl activator, the phenol structure in tannic acid is grafted onto the amino group in the chitosan molecular structure. The exposed phenol group can also increase the antibacterial activity of chitosan. While improving the reactivity of chitosan, it can also improve the bonding force between modified modal fiber and natural plant fiber, and enhance the antibacterial properties of the resulting blended yarn.

[0023] Preferably, the modal fiber undergoes an oxidative pretreatment; the oxidant includes one or a combination of two of potassium permanganate and sodium periodate.

[0024] Preferably, the steps for pre-treatment of modal fibers with an oxidant are as follows: an oxidant is added to deionized water to prepare an oxidant solution with a concentration of 1.2 to 1.3 g / L. Modal fibers are immersed in the oxidant solution at 50 to 70°C for 10 to 15 minutes, and then washed and dried to obtain oxidized modal fibers.

[0025] By adopting the above technical solution, the hydroxyl radicals contained on the surface of Modal fibers will aggregate into crystalline fibrillary structures of different levels in the solid state, resulting in the highly reactive hydroxyl portion being confined in the crystalline region, which in turn leads to a decrease in the grafting reactivity of Modal fibers. After oxidation treatment with an oxidant, the hydroxyl portion on the surface of Modal fibers is oxidized into carboxyl and aldehyde groups, which can enhance the reactivity with acrylic monomers and phenolic chitosan. Under the action of ethylenediamine, the resulting cross-linked network structure is more compact, the strength of the modified Modal is improved, the grafting rate is also enhanced, and the antibacterial properties of the resulting blended yarn are increased.

[0026] Secondly, this application also provides a method for preparing an environmentally friendly antibacterial blended yarn, comprising the following steps: S201. Dyed natural plant fibers and modified modal fibers are mixed in a certain mass ratio; S202. The mixed fibers obtained in step S201 are carded, wherein the sliver weight is 20-25 g / 5m. S203. The carded fibers are drawn into slivers using a three-stage blending process, with a number of slivers of 6 to 8. S204. The fibers after drawing are processed through roving and spinning processes to obtain environmentally friendly antibacterial blended yarn.

[0027] In summary, this application has the following beneficial effects: 1. The environmentally friendly antibacterial blended yarn of this application is obtained by blending natural plant fibers and modified modal fibers. Both are green and environmentally friendly fiber products. Natural plant fibers can provide some antibacterial properties, while modified modal fibers have high dry and wet strength, which can make up for the problem of insufficient strength of natural plant fibers. The resulting blended yarn has excellent strength and certain antibacterial properties.

[0028] 2. In this application, phenolic chitosan is grafted onto the surface of the modified modal fiber. Chitosan has excellent antibacterial properties and can achieve high-efficiency antibacterial activity by changing the permeability of bacterial cell membranes and inhibiting the DNA transcription process inside microbial cells. At the same time, the chitosan is also modified by tannic acid. The antibacterial properties of the chitosan after phenolic modification are improved to a certain extent. The catechol groups contained therein can also form strong hydrogen bonds with the hydroxyl radicals contained on the surface of plant fibers, so that the plant fibers and modified modal fibers can be tightly combined, improving the problem of poor cohesion between natural plant fibers, resulting in a significant improvement in the dry and wet strength of the blended yarn.

[0029] 3. In the post-treatment process of modified modal fiber, acrylic polymers are grafted onto the surface of the modal fiber. The added ethylenediamine further enables the grafted compounds to form a cross-linked network structure on the surface of the modal fiber, increasing stability and reactivity. Since the durability of fibers with antibacterial properties added through general post-treatment modification is not high, the cross-linked network structure formed on the surface of modal fiber by acrylic polymers and phenolic chitosan in this application can further improve the binding force of antibacterial substances on the fiber surface, reduce or avoid the loss of antibacterial properties of blended yarns, and increase the long-lasting antibacterial properties of blended yarns. Detailed Implementation

[0030] Preparation example of phenolic chitosan Preparation Example 1-1: A phenolic chitosan was prepared according to the following method: 10g of chitosan (85% degree of deacetylation) was added to 100ml of 2% acetic acid solution and stirred to dissolve, thus obtaining a chitosan solution. 35g of tannic acid was added to 250ml of methanol and stirred to dissolve, thus obtaining a tannic acid solution. The temperature of the chitosan solution was adjusted to 30℃. While stirring, the tannic acid solution and 3g of carboxyl activator were added, including 1.5g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 1.5g of N-hydroxysuccinimide. The reaction was stirred for 24h. After the reaction was completed, the chitosan was obtained by dialysis and freeze-drying.

[0031] Preparation Example 1-2 is a phenolic chitosan, which differs from Preparation Example 1-1 only in that the amount of tannic acid added is 30g.

[0032] Preparation Examples 1-3, a phenolic chitosan, differs from Preparation Example 1-1 only in that the amount of tannic acid added is 40g.

[0033] Preparation Examples 1-4: A phenolic chitosan, differing from Preparation Example 1-1 only in that the amount of tannic acid added is 20g.

[0034] Preparation Examples 1-5: A phenolic chitosan, differing from Preparation Example 1-1 only in that the amount of tannic acid added is 50g.

[0035] Preparation example of modified modal fiber Preparation Example 2-1: A modified modal fiber was prepared according to the following method: Sodium periodate was added to deionized water to prepare a sodium periodate solution with a concentration of 1.2 g / L. Modal fibers (fineness of 1.0 to 1.33 dtex) were immersed in the sodium periodate solution at 60°C for 10 min, and then washed and dried to obtain oxidized Modal fibers.

[0036] Acrylic acid and benzoyl peroxide in a mass ratio of 1:0.1 were added to deionized water to prepare a 10% post-treatment solution 1. The pH of post-treatment solution 1 was adjusted to 6. The bath ratio of oxidized modal fiber to post-treatment solution 1 was 1:22. The treatment temperature was 50℃ and the treatment time was 2h. After washing and drying, the first-treated modal fiber was obtained.

[0037] Ethylenediamine and phenolic chitosan prepared in Preparation Example 1-1 were added to deionized water at a mass ratio of 2:8 to prepare a post-treatment solution 2 with a mass fraction of 35%. After one treatment, the bath ratio of Modal fiber to post-treatment solution 2 was 1:30, the treatment temperature was 60°C, and the treatment time was 1 hour. Modified Modal fiber was then obtained after washing and drying.

[0038] Preparation Example 2-2, a modified modal fiber, differs from Preparation Example 2-1 only in that the post-treatment solution 1 has a mass fraction of 8%, and is prepared by mixing acrylic acid and benzoyl peroxide with deionized water in a mass ratio of 1:0.1.

[0039] Preparation Example 2-3, a modified modal fiber, differs from Preparation Example 2-1 only in that the mass fraction of posttreatment solution 1 is 12%, prepared by mixing acrylic acid and benzoyl peroxide with deionized water in a mass ratio of 1:0.1.

[0040] Preparation Example 2-4, a modified modal fiber, differs from Preparation Example 2-1 only in that the post-treatment solution 2 has a mass fraction of 30%, and is prepared by mixing ethylenediamine and phenolic chitosan obtained in Preparation Example 1-1 with deionized water in a mass ratio of 2:8.

[0041] Preparation Example 2-5, a modified modal fiber, differs from Preparation Example 2-1 only in that the post-treatment solution 2 has a mass fraction of 40%, and is prepared by mixing ethylenediamine and phenolic chitosan obtained in Preparation Example 1-1 with deionized water in a mass ratio of 2:8.

[0042] Preparation Example 2-6, a modified modal fiber, differs from Preparation Example 2-1 only in that the mass fraction of post-treatment solution 1 is 10%, prepared by mixing acrylic acid and benzoyl peroxide with deionized water in a mass ratio of 1:0.08; and the mass fraction of post-treatment solution 2 is 35%, prepared by mixing ethylenediamine and phenolic chitosan obtained in Preparation Example 1-1 with deionized water in a mass ratio of 3:7.

[0043] Preparation Example 2-7, a modified modal fiber, differs from Preparation Example 2-1 only in that the post-treatment solution 1 has a mass fraction of 10%, prepared by mixing acrylic acid and benzoyl peroxide with deionized water in a mass ratio of 1:0.12; and the post-treatment solution 2 has a mass fraction of 35%, prepared by mixing ethylenediamine and phenolic chitosan obtained in Preparation Example 1-1 with deionized water in a mass ratio of 2.5:7.5.

[0044] Preparation Example 2-8 is a modified modal fiber, which differs from Preparation Example 2-1 only in that an equal amount of phenolic chitosan obtained in Preparation Example 1-2 is used to replace the phenolic chitosan obtained in Preparation Example 1-1.

[0045] Preparation Examples 2-9: A modified modal fiber, which differs from Preparation Example 2-1 only in that an equal amount of phenolic chitosan obtained in Preparation Example 1-3 is used to replace the phenolic chitosan obtained in Preparation Example 1-1.

[0046] Preparation Example 2-10, a modified modal fiber, differs from Preparation Example 2-1 only in that an equal amount of phenolic chitosan obtained in Preparation Example 1-4 is used to replace the phenolic chitosan obtained in Preparation Example 1-1.

[0047] Preparation Example 2-11 is a modified modal fiber, which differs from Preparation Example 2-1 only in that an equal amount of phenolic chitosan obtained in Preparation Example 1-5 is used to replace the phenolic chitosan obtained in Preparation Example 1-1.

[0048] Preparation Example 2-12, a modified modal fiber, differs from Preparation Example 2-1 only in that the post-treatment solution 1 has a mass fraction of 6%, and is prepared by mixing acrylic acid and benzoyl peroxide with deionized water in a mass ratio of 1:0.1.

[0049] Preparation Example 2-13, a modified modal fiber, differs from Preparation Example 2-1 only in that the mass fraction of posttreatment solution 1 is 14%, prepared by mixing acrylic acid and benzoyl peroxide with deionized water in a mass ratio of 1:0.1.

[0050] Preparation Example 2-14, a modified modal fiber, differs from Preparation Example 2-1 only in that the post-treatment solution 2 has a mass fraction of 25%, and is prepared by mixing ethylenediamine and phenolic chitosan obtained in Preparation Example 1-1 with deionized water in a mass ratio of 2:8.

[0051] Preparation Example 2-15, a modified modal fiber, differs from Preparation Example 2-1 only in that the post-treatment solution 2 has a mass fraction of 45%, and is prepared by mixing ethylenediamine and phenolic chitosan obtained in Preparation Example 1-1 with deionized water in a mass ratio of 2:8.

[0052] Preparation Example 2-16, a modified modal fiber, differs from Preparation Example 2-1 only in that the mass fraction of post-treatment solution 2 is 35%, prepared from phenolic chitosan obtained in Preparation Example 1-1 and deionized water.

[0053] Preparation Example 2-17: A modified modal fiber was prepared according to the following method: Acrylic acid and benzoyl peroxide in a mass ratio of 1:0.1 were added to deionized water to prepare a 10% post-treatment solution 1. The pH of post-treatment solution 1 was adjusted to 6. The bath ratio of modal fiber to post-treatment solution 1 was 1:22. The treatment temperature was 50℃ and the treatment time was 2h. After washing and drying, the first-treatment modal fiber was obtained.

[0054] Ethylenediamine and phenolic chitosan prepared in Preparation Example 1-1 were added to deionized water at a mass ratio of 2:8 to prepare a post-treatment solution 2 with a mass fraction of 35%. After one treatment, the bath ratio of Modal fiber to post-treatment solution 2 was 1:30, the treatment temperature was 60°C, and the treatment time was 1 hour. Modified Modal fiber was then obtained after washing and drying.

[0055] Preparation Example 2-18: A modified modal fiber was prepared according to the following method: Sodium periodate was added to deionized water to prepare a sodium periodate solution with a concentration of 1.2 g / L. Modal fibers (fineness of 1.0 to 1.33 dtex) were immersed in the sodium periodate solution at 60°C for 10 min, and then washed and dried to obtain oxidized Modal fibers.

[0056] Ethylenediamine and phenolic chitosan prepared in Preparation Example 1-1 were added to deionized water at a mass ratio of 2:8 to prepare a post-treatment solution with a mass fraction of 35%. The bath ratio of oxidized modal fiber to the post-treatment solution was 1:30, the treatment temperature was 60°C, and the treatment time was 1 hour. Modified modal fiber was then obtained after washing and drying.

[0057] Preparation Example 2-19 is a modified modal fiber, which differs from Preparation Example 2-1 only in that an equal amount of chitosan (with a degree of deacetylation of 85%) is used to replace the phenolic chitosan obtained in Preparation Example 1-1.

[0058] Preparation Example 2-20: A modified modal fiber was prepared according to the following method: Sodium periodate was added to deionized water to prepare a sodium periodate solution with a concentration of 1.2 g / L. Modal fibers (fineness of 1.0 to 1.33 dtex) were immersed in the sodium periodate solution at 60°C for 10 min, and then washed and dried to obtain oxidized Modal fibers.

[0059] Acrylic acid and benzoyl peroxide in a mass ratio of 1:0.1 were added to deionized water to prepare a 10% post-treatment solution 1. The pH of post-treatment solution 1 was adjusted to 6. The bath ratio of oxidized modal fiber to post-treatment solution 1 was 1:22. The treatment temperature was 50℃ and the treatment time was 2h. After washing and drying, the first-treated modal fiber was obtained.

[0060] Ethylenediamine was added to deionized water to prepare a post-treatment solution 2 with a mass fraction of 35%. After one treatment, the bath ratio of modal fiber to post-treatment solution 2 was 1:30, the treatment temperature was 60℃, and the treatment time was 1h. Modified modal fiber was then obtained after washing and drying. Example

[0061] Example 1: An environmentally friendly antibacterial blended yarn was prepared according to the following method: 3.5 kg of Ula grass fiber, 1.5 kg of lotus root fiber, 2 kg of almond fiber, and 3 kg of modified modal fiber prepared in Preparation Example 2-1 were dyed separately; then the dyed fibers were thoroughly mixed. The obtained mixed fibers were carded, with a sliver weight of 23g / 5m. During the carding process, the distance between the cylinder and the licker-in was set to 0.24mm, the distance between the cylinder and the flat plate in the spinning machine was 0.28mm, the distance between the cylinder and the doffer was 0.18mm, and the linear speed ratio of the cylinder and the licker-in was 2.7. Then, the carded fibers are drawn into slivers using a three-stage blending process, with 8 slivers drawn at a sliver weight of 24g / 5m, a draft ratio of 10, and a machine speed of 220m / min. Finally, the fibers after drawing are processed through roving and spinning processes to obtain environmentally friendly antibacterial blended yarn. In the roving process, the yarn weight is 5g / 10m, the twist coefficient is 95, and the roller nip spacing is 32mm. In the spinning process, the yarn twist coefficient is 380, and the roller nip spacing is 30mm.

[0062] Example 2, an environmentally friendly antibacterial blended yarn, differs from Example 1 only in that the amount of Ula grass fiber added is 3 kg, while the amount of modified modal fiber added in Preparation Example 1-1 is 3.5 kg.

[0063] Example 3: An environmentally friendly antibacterial blended yarn, which differs from Example 1 only in that it does not contain lotus root fiber and almond fiber, and the amount of ula grass fiber added is 7 kg.

[0064] Example 4: An environmentally friendly antibacterial blended yarn, which differs from Example 1 only in that the modified modal fiber prepared in Example 2-1 is replaced with an equal amount of the modified modal fiber prepared in Example 2-2.

[0065] Example 5: An environmentally friendly antibacterial blended yarn, which differs from Example 1 only in that the modified modal fiber prepared in Example 2-1 is replaced with an equal amount of modified modal fiber prepared in Example 2-3.

[0066] Example 6: An environmentally friendly antibacterial blended yarn, which differs from Example 1 only in that the modified modal fiber prepared in Example 2-1 is replaced with an equal amount of modified modal fiber prepared in Example 2-4.

[0067] Example 7: An environmentally friendly antibacterial blended yarn, which differs from Example 1 only in that the modified modal fiber prepared in Example 2-1 is replaced with an equal amount of the modified modal fiber prepared in Example 2-5.

[0068] Example 8, an environmentally friendly antibacterial blended yarn, differs from Example 1 only in that the modified modal fiber prepared in Example 2-1 is replaced with an equal amount of modified modal fiber prepared in Example 2-6.

[0069] Example 9, an environmentally friendly antibacterial blended yarn, differs from Example 1 only in that the modified modal fiber prepared in Example 2-1 is replaced with an equal amount of modified modal fiber prepared in Example 2-7.

[0070] Example 10: An environmentally friendly antibacterial blended yarn, which differs from Example 1 only in that the modified modal fiber prepared in Example 2-1 is replaced with an equal amount of the modified modal fiber prepared in Example 2-8.

[0071] Example 11, an environmentally friendly antibacterial blended yarn, differs from Example 1 only in that the modified modal fiber prepared in Example 2-1 is replaced with an equal amount of modified modal fiber prepared in Example 2-9.

[0072] Example 12, an environmentally friendly antibacterial blended yarn, differs from Example 1 only in that the modified modal fiber prepared in Preparation Example 2-1 is replaced with an equal amount of modified modal fiber prepared in Preparation Example 2-10.

[0073] Example 13, an environmentally friendly antibacterial blended yarn, differs from Example 1 only in that the modified modal fiber prepared in Example 2-1 is replaced with an equal amount of modified modal fiber prepared in Example 2-11.

[0074] Example 14, an environmentally friendly antibacterial blended yarn, differs from Example 1 only in that the modified modal fiber prepared in Example 2-1 is replaced with an equal amount of modified modal fiber prepared in Example 2-12.

[0075] Example 15, an environmentally friendly antibacterial blended yarn, differs from Example 1 only in that the modified modal fiber prepared in Example 2-1 is replaced with an equal amount of modified modal fiber prepared in Example 2-13.

[0076] Example 16, an environmentally friendly antibacterial blended yarn, differs from Example 1 only in that the modified modal fiber prepared in Example 2-1 is replaced with an equal amount of modified modal fiber prepared in Example 2-14.

[0077] Example 17, an environmentally friendly antibacterial blended yarn, differs from Example 1 only in that the modified modal fiber prepared in Example 2-1 is replaced with an equal amount of modified modal fiber prepared in Example 2-15.

[0078] Example 18, an environmentally friendly antibacterial blended yarn, differs from Example 1 only in that the modified modal fiber prepared in Preparation Example 2-1 is replaced with an equal amount of modified modal fiber prepared in Preparation Example 2-16.

[0079] Example 19, an environmentally friendly antibacterial blended yarn, differs from Example 1 only in that the modified modal fiber prepared in Example 2-1 is replaced with an equal amount of modified modal fiber prepared in Example 2-17.

[0080] Comparative Example Comparative Example 1, an environmentally friendly antibacterial blended yarn, differs from Example 1 only in that the amount of Ula grass fiber added is 4 kg, while the amount of modified modal fiber added in Preparation Example 1-1 is 2.5 kg.

[0081] Comparative Example 2, an environmentally friendly antibacterial blended yarn, differs from Example 1 only in that the amount of Ula grass fiber added is 2.5 kg, while the amount of modified modal fiber added in Preparation Example 1-1 is 4 kg.

[0082] Comparative Example 3 is an environmentally friendly antibacterial blended yarn, which differs from Example 1 only in that the modified modal fiber prepared in Example 2-1 is replaced with an equal amount of modified modal fiber prepared in Example 2-18.

[0083] Comparative Example 4, an environmentally friendly antibacterial blended yarn, differs from Example 1 only in that the modified modal fiber prepared in Example 2-1 is replaced with an equal amount of modified modal fiber prepared in Example 2-19.

[0084] Comparative Example 5, an environmentally friendly antibacterial blended yarn, differs from Example 1 only in that the modified modal fiber prepared in Preparation Example 2-1 is replaced with an equal amount of modified modal fiber prepared in Preparation Example 2-20.

[0085] Comparative Example 6, an environmentally friendly antibacterial blended yarn, differs from Example 1 only in that an equal amount of unmodified modal fiber is used to replace the modified modal fiber prepared in Preparation Example 2-1.

[0086] Performance testing 1. Antibacterial Performance Test: The antibacterial rate of the blended yarns obtained in the examples and comparative examples was tested according to the relevant descriptions in GB / T 20944.3-2008 "Evaluation of Antibacterial Properties of Textiles - Part 3: Vibration Method". The blended yarns were subjected to 20 washes using the washing method in 10.1.1 of the standard to test their antibacterial wash resistance. The selected bacterial strains were Candida albicans, Escherichia coli, and Staphylococcus aureus.

[0087] The experimental results are shown in Table 1.

[0088] 2. Dry and wet strength tests: The dry and wet strengths of the blended yarns obtained in the examples and comparative examples were tested according to the relevant records in GB / T 3923.1-2013 "Textiles - Tensile properties of fabrics - Part 1: Determination of breaking strength and elongation at break (strip method)".

[0089] The experimental results are shown in Table 2.

[0090] Table 1. Test Results of Antibacterial Properties of Blended Yarns Table 2 Strength Test Results of Blended Yarns Based on Tables 1 and 2, and in conjunction with Examples 1, 2, and 3, it can be seen that Examples 2 and 3 show no significant changes in antibacterial rate and wet / dry strength before and after washing for different bacteria compared to Example 1. This indicates that the antibacterial properties, antibacterial wash resistance, and mechanical strength of Examples 2 and 3 are not significantly different from those of Example 1. This may be because in Example 2, the ratio between modified modal fiber and natural plant fiber was varied within the required range, indicating that changing the fiber ratio within the required range has no significant impact on the performance of the resulting blended yarn. In Example 3, the type of natural plant fiber changed, indicating that changing the type of natural plant fiber within the required range has a relatively small impact on the performance of the resulting blended yarn.

[0091] Combining Examples 1 and 4-9, it can be seen that the antibacterial rate and wet / dry strength of Examples 4-9 for different bacteria before and after washing are not significantly different from those of Example 1. This indicates that the antibacterial properties, antibacterial wash resistance, and mechanical strength of Examples 4-9 are not significantly different from those of Example 1. This may be because the difference between Examples 4-9 and Example 1 lies only in the variation of the concentration and ratio of post-treatment modifier 1 and modifier 2 during the modification of modifier fibers within the required range. This suggests that varying the concentration and ratio of the modifiers within the required range has no significant impact on the performance of the resulting blended yarn.

[0092] Combining Examples 1, 10, and 11, it can be seen that Examples 10 and 11 show no significant changes in the antibacterial rate and wet / dry strength for different bacteria before and after washing compared to Example 1. This indicates that the antibacterial properties, antibacterial wash resistance, and mechanical strength of Examples 10 and 11 are not significantly different from those of Example 1. This may be because the only difference between Examples 10 and 11 and Example 1 is that the proportion of phenolic chitosan used in the post-treatment modifier 2 was varied within the required range during preparation. This suggests that varying the proportion of phenolic chitosan within the required range has no significant impact on the properties of the resulting blended yarn.

[0093] Combining Examples 1, 12, and 13, it can be seen that the difference in antibacterial rate before and after washing increases in Examples 12 and 13. The antibacterial rate after water absorption decreases compared to Example 1, and the dry and wet strength decreases slightly. This indicates that the antibacterial properties, antibacterial wash resistance, and mechanical strength of Examples 12 and 13 are lower than those of Example 1. The reason for this may be that the amount of tannic acid added during the preparation of the modified modal fiber used in Examples 12 and 13 was not within the required range, resulting in a decrease in the phenolic group content in the phenolic chitosan of the modified modal fiber used in Example 12. This reduces the adhesion of phenolic chitosan to the surface of the modified modal fiber, leading to a significant decrease in antibacterial performance after washing. Simultaneously, it reduces the bonding force between the modified modal fiber and the natural plant fiber, and also decreases the dry and wet strength.

[0094] Combining Examples 1, 14, and 15, it can be seen that the difference in antibacterial rate before and after washing increases in Examples 14 and 15. The antibacterial rate after water absorption is lower than that in Example 1, and the dry and wet strength is slightly lower, indicating that the antibacterial properties, antibacterial wash resistance, and mechanical strength of Examples 14 and 15 are lower than those of Example 1. This may be because the amount of acrylic acid added to the modified modal fibers used in Examples 14 and 15 changes during the post-treatment process. When the amount of acrylic acid added decreases, the cross-linking strength of the modified modal fiber surface decreases, the strength of the blended yarn decreases, and the number of active sites on the modified modal fiber surface also decreases, reducing the binding force between the modified modal fiber and phenolic chitosan, leading to a decrease in antibacterial properties. Furthermore, without a tight cross-linking structure, the phenolic chitosan easily detaches during washing, losing its antibacterial effect. When the amount of acrylic acid added increases, the cross-linking density becomes too high, resulting in a decrease in mechanical properties.

[0095] Combining Examples 1, 16, and 17, it can be seen that the difference in antibacterial rate before and after washing increases in Examples 16 and 17. The antibacterial rate after water absorption decreases compared to Example 1, and the dry and wet strength decreases slightly. This indicates that the antibacterial properties, antibacterial wash resistance, and mechanical strength of Examples 16 and 17 are lower than those of Example 1. This may be because the amount of phenolic chitosan added to the modified modal fibers used in Examples 16 and 17 changes during the post-treatment process. When the amount of phenolic chitosan added decreases, the antibacterial properties decrease accordingly. Simultaneously, without the interaction of phenolic groups, the binding force decreases, resulting in a decrease in antibacterial water resistance and mechanical strength. When the amount of added phenolic chitosan is excessive, the tannic acid contains a large number of benzene ring structures. Excessive addition leads to high rigidity and steric hindrance, which also inhibits the grafting rate of phenolic chitosan on the surface of the modal fibers.

[0096] Combining Examples 1 and 18, it can be seen that the difference in antibacterial rate before and after washing increases in Example 18, and the antibacterial rate decreases compared to Example 1. The dry and wet strength also decreases, indicating that the antibacterial properties, antibacterial wash resistance, and mechanical strength of Example 18 are lower than those of Example 1. This may be because ethylenediamine was not added to the modified modal fiber during post-treatment in Example 18. Without the cross-linking effect of ethylenediamine, it is difficult to form a cross-linked network structure on the surface of the modified modal fiber, resulting in a decrease in mechanical strength. Furthermore, the binding force of phenolic chitosan on the modal fiber surface decreases, leading to a significant decrease in the antibacterial rate after washing.

[0097] Combining Examples 1 and 19, it can be seen that the difference in antibacterial rate before and after washing increases in Example 19, and the antibacterial rate decreases compared to Example 1. The dry and wet strength also decreases, indicating that the antibacterial properties, antibacterial wash resistance, and mechanical strength of Example 19 are lower than those of Example 1. This may be because the modified modal fiber in Example 19 did not undergo oxidative pretreatment before post-treatment, resulting in a reduction in the number of oxygen-containing free radicals on the fiber surface and a decrease in the grafting rate with acrylic acid and phenolic chitosan, thus leading to a decline in various properties.

[0098] Based on Examples 1, 1, 2, and 6, it can be seen that the difference in antibacterial rate before and after washing increases in Examples 1, 2, and 6. The antibacterial rate before and after washing is lower than in Example 1, and the dry and wet strength is also lower, with Comparative Example 6 showing a significant decrease. This indicates that the antibacterial properties, antibacterial wash resistance, and mechanical strength of Comparative Examples 1, 2, and 6 are lower than in Example 1. This may be because the proportion of modified modal fiber in Comparative Example 1 is reduced, resulting in a decrease in the content of phenolic chitosan, which reduces both antibacterial properties and binding force. Comparative Example 6 did not add modified modal fiber. Modified modal fiber has high dry and wet strength, and blending it with natural plant fibers can improve the strength of the blended yarn. Furthermore, the phenolic chitosan grafted onto the surface of the modified modal fiber can improve the mechanical strength and antibacterial properties of the yarn. In Comparative Example 2, the proportion of modified modal fiber is increased, but in the blended yarn, a high proportion of viscose fiber will have a negative impact on the yarn strength.

[0099] Combining Example 1 and Comparative Example 3, it can be seen that the difference in antibacterial rate before and after washing in Comparative Example 3 is larger, and the antibacterial rate before and after washing is lower than that in Example 1. The dry and wet strengths are also lower, indicating that the antibacterial properties, antibacterial wash resistance, and mechanical strength of Comparative Example 3 are lower than those of Example 1. This may be because the modified modal fiber in Comparative Example 3 was not treated with acrylic acid during the post-processing. Consequently, no cross-linking network was formed on the modified modal surface, and the number of reactive sites on the surface was reduced, leading to a decrease in the grafting rate of phenolic chitosan and a decrease in the bonding force between the modified modal fiber and the natural plant fiber. Ultimately, this resulted in a decrease in both the antibacterial properties and mechanical strength of the obtained yarn.

[0100] Combining Examples 1, 4, and 5, the difference in antibacterial rate before and after washing increased in Examples 4 and 5. The antibacterial rate decreased compared to Example 1, and the dry and wet strength also decreased, with Example 5 showing a significant decrease. This indicates that the antibacterial properties, antibacterial wash resistance, and mechanical strength of Examples 4 and 5 decreased compared to Example 1. The reason for this may be that in Example 4, the chitosan added to the modified modal fiber during post-treatment was not phenolically modified, resulting in decreased bonding strength with natural plant fibers. Poor cohesion between plant fibers led to decreased mechanical strength of the resulting yarn. Simultaneously, the bonding strength between the chitosan and the cross-linked network on the surface of the modified modal fiber decreased, making it easier for the chitosan to detach during washing, thus reducing the yarn's antibacterial properties. In Example 5, the modified modal fiber did not undergo surface treatment with phenolic chitosan during post-treatment, lacking the antibacterial effect of chitosan, resulting in a significant decrease in the antibacterial properties of the resulting yarn.

[0101] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An environmentally friendly antibacterial blended yarn, characterized in that, The raw materials of the blended yarn include natural plant fibers and modified modal fibers in a mass ratio of (65-70):(30-35); the surface of the modified modal fibers is grafted with phenolic chitosan. The modified modal fiber was prepared according to the following method: S101. Add post-treatment modifier 1 to deionized water to prepare post-treatment solution 1 with a mass fraction of 8-12%. Adjust the pH of post-treatment solution 1 to 5-6. The bath ratio of modal fiber to post-treatment solution 1 is 1:(20-25). The treatment temperature is 50-60℃ and the treatment time is 2-3h. After washing and drying, the modal fiber after one treatment is obtained. S102. Add post-treatment modifier 2 to deionized water to prepare post-treatment solution 2 with a mass fraction of 30-40%. After one treatment, the bath ratio of modal fiber to post-treatment solution 2 is 1:(30-32), the treatment temperature is 55-60℃, the treatment time is 1-1.5h, and then the modified modal fiber is obtained after washing and drying. The post-treatment modifier 1 comprises an acrylic monomer and an initiator in a mass ratio of 1:(0.08-0.12); the acrylic monomer comprises one or a combination of acrylic acid, methacrylic acid, and acrylamide. The post-treatment modifier 2 comprises ethylenediamine and phenolic chitosan in a mass ratio of (2-3):(7-8); the raw material for the phenolic chitosan comprises chitosan, tannic acid and carboxyl activator in a mass ratio of 1:(3-4):(0.2-0.4); the carboxyl activator is a mixture of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide in a mass ratio of 1:(1-1.2). The phenolic chitosan was prepared by the following method: chitosan was added to an acetic acid solution and stirred to dissolve to obtain a chitosan solution; tannic acid was added to a solvent and stirred to dissolve to obtain a tannic acid solution; the temperature of the chitosan solution was adjusted to 30-35℃, and tannic acid solution and carboxyl activator were added while stirring, and the reaction was stirred for 20-24 hours. After the reaction was completed, the chitosan was obtained by dialysis and freeze-drying. The modal fiber is pretreated with an oxidizing agent; the oxidizing agent includes one or a combination of two of potassium permanganate and sodium periodate. The steps for pre-treatment of modal fibers with an oxidizing agent are as follows: An oxidizing agent is added to the deionized water... An oxidant solution with a concentration of 1.2–1.3 g / L was prepared in water. Modal fibers were then immersed in the oxidant solution at 50–70°C. The fibers are soaked in the solution for 10-15 minutes, then washed and dried to obtain oxidized modal fibers.

2. The environmentally friendly antibacterial blended yarn according to claim 1, characterized in that, The natural plant fibers include one or a combination of several of the following: Ula grass fiber, flax fiber, bamboo fiber, lotus root fiber, and almond fiber.

3. A method for preparing environmentally friendly antibacterial blended yarn for any one of claims 1 to 2, characterized in that, It is prepared by the following steps: S201. Dyed natural plant fibers and modified modal fibers are mixed in a certain mass ratio; S202. The mixed fibers obtained in step S201 are carded, wherein the sliver weight is 20-25 g / 5m. S203. The carded fibers are drawn into slivers using a three-stage blending process, with a number of slivers of 6 to 8. S204. The fibers after drawing are processed through roving and spinning processes to obtain environmentally friendly antibacterial blended yarn.

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