Bio-based blended yarn and preparation method and application thereof

Abstract

The invention relates to the field of textile materials, and particularly discloses a bio-based blended yarn and a preparation method and application thereof.The preparation method comprises the following steps that S1, a polyvinyl alcohol solution is added into a sodium alginate solution, then a dispersing aid and a stabilizer are added, degassing and filtering are conducted after uniform stirring, and a spinning solution is prepared; s2, dissolving an antibacterial agent in a solvent to prepare an antibacterial solution, adding a co-emulsifier, and homogenizing to prepare a nano dispersion; s3, mixing the nano dispersion with a spinning solution to prepare an antibacterial spinning solution; s4, the antibacterial spinning solution is subjected to wet spinning, initial set fibers are prepared and then subjected to post-treatment, and bio-based blended yarn is prepared; the invention further discloses the bio-based blended yarn prepared through the method and application of the bio-based blended yarn in the field of textile materials. The bio-based yarn has the advantages of being high in strength and resistant to washing.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of textile materials, more particularly, it relates to a bio-based blended yarn and a preparation method and application thereof. BACKGROUND

[0002] In recent years, with the enhancement of environmental awareness and the deepening of the concept of sustainable development, bio-based functional textile materials have gradually become a research hotspot in the field of textile science due to their renewable source, good biocompatibility and environmental friendliness. In particular, natural polymer materials represented by sodium alginate (SA) have shown broad application prospects in the fields of warmth, medical treatment and functional textile materials due to their unique chemical structure and physical properties.

[0003] Alginate-based fibers are usually prepared by aqueous wet spinning technology, i.e. extruding the sodium alginate solution into a coagulation bath containing calcium ions (Ca 2+ ) to form a stable fiber structure by in-situ cross-linking reaction of Ca 2+ with carboxyl groups on the molecular chain of sodium alginate. Although alginate-based fibers have shown great potential in the fields of warmth and functional textiles, there are still deficiencies that need to be overcome.

[0004] Sodium alginate fibers prepared by traditional Ca 2+ gelation generally have the problems of low strength, high brittleness, strong hydrophilicity and performance degradation in a humid heat environment, which seriously limit their application in the industrialized warmth textile field. Moreover, there are certain requirements for the functionality of textiles at present, and it is also of great significance to efficiently encapsulate and long-term maintain hydrophobic active substances with antibacterial and sweat odor inhibiting functions to improve their wash resistance and antibacterial durability.

[0005] Therefore, bio-based yarns with high strength and wash resistance are of great significance for bio-based functional textile materials. SUMMARY

[0006] In order to obtain bio-based yarns with high strength and wash resistance, the present application provides a bio-based blended yarn and a preparation method and application thereof.

[0007] In a first aspect, the present application provides a preparation method of a bio-based blended yarn, which adopts the following technical scheme: A preparation method of a bio-based blended yarn, comprising the following steps: S1, adding a polyvinyl alcohol solution to a sodium alginate solution, then adding a dispersing aid and a stabilizer, stirring uniformly, degassing, filtering, and preparing a spinning solution; S2, dissolving an antibacterial agent in a solvent to prepare an antibacterial solution, then adding an emulsifying aid and homogenizing to prepare a nanodispersion; S3, the nanodispersion is mixed with the spinning solution to obtain an antibacterial spinning solution; S4, the antibacterial spinning solution is subjected to wet spinning to obtain a primary coagulation fiber, and the bio-based blended yarn is obtained after post-treatment, and the formula of the coagulation bath in the wet spinning process is calcium chloride, water and low alcohol in a mass ratio of 5:(40-50):(40-50).

[0008] By adopting the above technical scheme, the yarn in the application is prepared by blending sodium alginate and polyvinyl alcohol and then wet spinning. The alginate chains are rapidly ionically crosslinked to form primary coagulation bodies by calcium ions, and the polyvinyl alcohol provides compactness and plasticity by hydrogen bonding with sodium alginate during the coagulation process. The polyvinyl alcohol and sodium alginate molecules are interwoven to form a network structure with certain structure and strength. The dispersing aid makes each component uniformly dispersed in the solution to avoid agglomeration, and the stabilizer prevents the solution from delaminating or precipitating during storage and use, thereby ensuring the stability of the spinning solution. Compared with traditional calcium gel fibers, the strength and elastic modulus of the yarn are significantly improved, and the crystallinity is significantly increased, thereby meeting the mechanical stability requirements of thermal textiles.

[0009] In the wet spinning process, the antibacterial spinning solution is extruded from the spinneret into the coagulation bath. The calcium chloride in the coagulation bath reacts with the sodium alginate to replace the sodium ions on the sodium alginate molecular chain with calcium ions to form a calcium alginate gel structure, thereby solidifying the spinning solution into a yarn. The mixed solvent of water and low alcohol adjusts the coagulation speed and improves the yarn structure. Water is the main coagulation medium, and low alcohol can reduce the surface tension of the solution, making the coagulation process more uniform, and also helping the diffusion and discharge of the solvent, reducing internal defects of the yarn, and improving the strength and uniformity of the yarn. In the application, the coagulation bath formula is precisely controlled, so that the spun bio-based blended yarn not only has high strength, but also has a tight and uniform internal structure, providing a structural basis for the yarn to maintain good performance after multiple washes.

[0010] In addition, an antibacterial liquid is also added in the present application, the antibacterial agent has natural antibacterial activity, and is dissolved in a suitable solvent to form an antibacterial liquid. After adding a co-emulsifier, homogenization treatment is carried out, the antibacterial agent particles are refined to a nanometer level through mechanical action, the co-emulsifier is adsorbed on the surface of the nano particles to form a protective film, the mutual aggregation between the nano particles is prevented, and a stable nano dispersion is obtained. The antibacterial agent nano particles in the nano dispersion are uniformly dispersed in the spinning solution, and the antibacterial agent nano particles are stably present in the mixed system for spinning through the interaction of various components in the spinning solution. Compared with the current antibacterial agent surface treatment method, the washing resistance is poor, while in the present application, the antibacterial agent is added into the sodium alginate spinning matrix through the blending spinning method, the fiber is formed through wet spinning, the antibacterial agent is uniformly dispersed in the fiber in the form of nano particles, the whole antibacterial structure is formed, the antibacterial agent is wrapped by the fiber matrix, the loss during washing is reduced, and the antibacterial component penetrates the fiber cross section, so that even if the surface is worn, the internal part can still continuously release the antibacterial activity. Finally, the yarn prepared in the present application has better strength and elastic modulus, the antibacterial residual rate after washing is obviously improved, has better antibacterial stability and durability, has better washing-resistant antibacterial function, and as a bio-based fiber, has better physical strength.

[0011] Optionally, the adding mass ratio of polyvinyl alcohol and sodium alginate in step S1 is (10-40):(60-90), the concentration of the sodium alginate solution is 1.5-7.5wt%, and the addition of the polyvinyl alcohol solution makes the viscosity of the spinning solution 20000-60000 mPa·s (cP), and more preferably 38000-45000 mPa·s (cP).

[0012] By adopting the above technical solution, the adding mass ratio of sodium alginate and polyvinyl alcohol is better for the mechanical properties and spinnability of the yarn, and the regulation of the viscosity of the spinning solution realizes stable extrusion and fiber forming.

[0013] Optionally, the dispersing aid is selected from oligomeric polyvinyl alcohol, and the stabilizer is selected from polyethylene glycol 4000, and the dispersing aid is prepared into a 0.1-0.3wt% solution for addition, and the polyethylene glycol 4000 is prepared into a 0.05-0.15wt% solution for addition.

[0014] Optionally, the low alcohol in the coagulation bath is selected from one or more of ethanol, isopropyl alcohol or propylene glycol.

[0015] Optionally, the number average molecular weight of the polyvinyl alcohol in step S1 is 89000-146000, and the number average molecular weight of the oligomeric polyvinyl alcohol of the dispersing aid is 25000-35000.

[0016] Optionally, the solvent in step S2 is selected from one or more of isopropyl alcohol, ethanol and propylene glycol. The co-emulsifiers are selected from one or more of oligomeric PVA, PEG, PVP and sodium alginate.

[0017] Optionally, the concentration of the antibacterial agent in the antibacterial solution in step S2 is 4-8wt%, the addition amount of the antibacterial agent is 1-3wt% of the sum of the addition amounts of polyvinyl alcohol and sodium alginate, the addition amount of the co-emulsifier is 8-10wt% of the mass of the antibacterial agent, and the nanodispersion is prepared by high-pressure homogenization cycle treatment at 800bar for 3-5 times.

[0018] By adopting the above technical solution, the nanodispersion with an average particle size of 300-600nm and a polydispersity index (PDI) (Z-average particle size and polydispersity index (PDI) values obtained under the condition of dynamic light scattering (DLS) at 25℃ and a scattering angle of 90°) ≤0.3 is prepared by the above processing.

[0019] Optionally, the post-treatment in step S4 includes wet drawing and heat setting performed in sequence. The wet drawing is specifically performed as follows: the as-spun fiber is first washed and then subjected to preliminary drawing at a draw ratio of 1.2-4.0 in a wet state, and then subjected to wet heat drawing at a draw ratio of 1.5-6.0 in a hot water bath at 60-120℃; and the heat setting temperature is 80-150℃.

[0020] By adopting the above technical solution, the molecular orientation and crystallinity are improved by first performing preliminary drawing on the as-spun fiber and then performing wet heat drawing, thereby improving the mechanical properties of the yarn. Moreover, the linear arrangement of the spinning solution viscosity, the coagulation bath formula, and the drawing and heat setting parameters in the present application can realize long-time continuous wet spinning with significantly reduced short fiber rate.

[0021] Optionally, after the spinning solution is prepared in step S1, polyhydric alcohol and organic acid are further added to the spinning solution. The addition of the organic acid makes the pH value of the spinning solution 2-4, and the addition amount of the polyhydric alcohol is 2-5wt% of the spinning solution.

[0022] By adopting the above technical solution, when the polyhydric alcohol and the acid are further added to the spinning solution, the esterification between the carboxyl groups of the alginate and the polyhydric alcohol occurs under the catalysis of the acid and in the presence of the polyhydric alcohol, and the in-situ esterification reaction is promoted during the wet heat drawing stage in the post-treatment stage, thereby realizing in-situ esterification modification, significantly improving the hydrophobicity and washability of the yarn fiber, and also improving the mechanical properties of the yarn fiber. By controlling the addition amount of the polyhydric alcohol, the esterification reaction can be ensured to proceed, the hydrophobicity is improved, and the viscosity is prevented from being too high.

[0023] Optionally, the polyhydric alcohol is selected from one or both of glycerol and 1,2-propanediol.

[0024] In a second aspect, the present application provides a bio-based blended yarn, which adopts the following technical solution: A bio-based blended yarn is prepared by the aforementioned method.

[0025] By adopting the above technical solution and the method provided in this application, the alginate chain achieves rapid ionic cross-linking through Ca2+ to form a primary solid. During the solidification process, PVA interacts with SA through hydrogen bonds to provide density and plasticity. Under acid catalysis and in the presence of polyols, some carboxyl groups of alginate undergo esterification with polyols (forming an AE structure) or esterification is promoted by humid heat in the post-treatment stage, thereby significantly improving hydrophobicity and water resistance. Ultimately, the mechanical properties of the yarn obtained in this application are significantly improved, such as breaking strength. At the same time, its water resistance and hydrophobicity are significantly improved. Furthermore, after nano-dispersion pretreatment, its wash resistance and antibacterial properties are also better. Moreover, it releases spinning over a long period of time and the breakage rate is significantly reduced, making it suitable for continuous industrial production.

[0026] Thirdly, this application provides an application of a bio-based blended yarn, employing the following technical solution: Application of a bio-based blended yarn in textile materials.

[0027] The yarn produced in this application has higher physical properties. It is bio-based, renewable, and more biocompatible. It also has better physical property parameters and has better application prospects in thermal insulation, medical and functional textile materials, especially meeting the requirements of high mechanical performance.

[0028] In summary, this application has the following beneficial effects: 1. In this application, the yarn is made by wet spinning after blending sodium alginate and polyvinyl alcohol. The alginate chains achieve rapid ionic cross-linking through calcium ions to form a primary solid. During the re-solidification process, polyvinyl alcohol interacts with sodium alginate through hydrogen bonds to provide density and plasticity. The molecules of polyvinyl alcohol and sodium alginate intertwine to form a network structure with certain structure and strength. Compared with traditional calcium gel fiber, its strength and elastic modulus are significantly improved, and its crystallinity is significantly increased, thus meeting the mechanical stability requirements of thermal insulation textiles. 2. In this application, the antibacterial spinning solution enters the coagulation bath after being extruded from the spinneret. The coagulation bath formula is precisely controlled so that the spun bio-based blended yarn not only has high strength, but also has a dense and uniform internal structure, providing a structural basis for the yarn to maintain good performance after multiple washes. 3、The antibacterial agent in the application is refined to the nanometer level, the antibacterial agent nanoparticles in the nanodispersion are uniformly dispersed in the spinning solution, and the antibacterial agent nanoparticles are stably present in the mixed system for spinning by means of the interaction of each component in the spinning solution. Compared with the current antibacterial agent surface treatment method, the wash resistance is poor, while in the application, the antibacterial agent is added to the sodium alginate spinning matrix by blending spinning, and the fiber is formed by wet spinning. The antibacterial agent is uniformly dispersed in the fiber in the form of nanoparticles, forming an overall antibacterial structure. The antibacterial agent is wrapped by the fiber matrix, reducing the loss during washing, and the antibacterial component penetrates the fiber cross section. Even if the surface is worn, the internal can still continuously release antibacterial activity. 4、The yarn prepared in the application has better strength and elastic modulus, and the antibacterial residual rate after washing is significantly improved, has better antibacterial stability and durability, has better wash-resistant antibacterial function, and as a bio-based fiber, has better physical strength. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is the process flow chart in Example 1 of the application. DETAILED DESCRIPTION

[0030] The application will be further described in conjunction with the following examples. It is particularly pointed out that: in the following examples, the specific conditions are not specified, and the conventional conditions or the conditions recommended by the manufacturer are used. The raw materials used in the following examples can be obtained from ordinary market sources unless otherwise specified.

[0031] In order to prepare a hydrophobic active substance in a yarn fiber that has high strength and significant water resistance, can efficiently encapsulate and long-acting maintain antibacterial and sweat odor inhibition functions, and has high wash resistance, the method provided by the application is prepared by blending sodium alginate and polyvinyl alcohol and then wet spinning. In the wet spinning process, the nanodispersed hinokitiol antibacterial agent is blended to prepare an antibacterial spinning solution, and then after degassing and filtration, it is extruded through a porous spinneret into a ternary coagulation bath containing calcium ions and a lower alcohol, so that the fiber undergoes ion crosslinking and partial catalytic in-situ esterification during the coagulation process. Subsequently, after washing or alcohol replacement, wet drawing, wet heat drawing and heat setting processes, a continuous filament with high strength, wash resistance and functional encapsulation performance is obtained and made into a yarn. By limiting the spinning solution viscosity, the mass ratio of polyvinyl alcohol to sodium alginate, the composition and proportion of the coagulation bath, and the coagulation bath temperature and wet drawing and heat setting temperature, the stability of continuous spinning and the mechanical or functional properties of the fiber are ensured.

[0032] The antibacterial active substance in the application is hinokitiol, curcumin and other antibacterial agents. The following examples will be described taking hinokitiol as an example.

[0033] The following will be described in conjunction with specific examples.

[0034] Example 1 A method for preparing a bio-based blended yarn, comprising Figure 1 , comprising the following steps: S1, sodium alginate is added to 50℃ deionized water and stirred to dissolve uniformly to obtain a sodium alginate solution with a concentration of 3wt%, and then cooled to room temperature for standby; Polyvinyl alcohol with a number average molecular weight of 100000 is dissolved in warm water at 80℃ under high-speed shearing (rotation speed is 1000rpm) to obtain a uniform polyvinyl alcohol solution, and then cooled to 40℃ for standby; The polyvinyl alcohol solution is added to the sodium alginate solution, and then a dispersing aid and a stabilizer are added. After uniform stirring under high-speed shearing, degassing (under vacuum for 10min) and filtration (through a 400 mesh metal filter), a spinning solution is prepared; The dispersing aid is selected as low molecular weight polyvinyl alcohol with a number average molecular weight of 30000, the stabilizer is selected as polyethylene glycol 4000, and the dispersing aid is mixed with water to prepare a 0.2wt% solution for addition, the polyethylene glycol 4000 is prepared as a 0.1wt% solution for addition, the mass ratio of polyvinyl alcohol to sodium alginate is 20:80, and the concentration of the polyvinyl alcohol solution is such that the viscosity of the spinning solution is 30000mPa·s(cP); S2, the antibacterial solution is prepared by dissolving hinokitiol in solvent isopropyl alcohol, the concentration of hinokitiol in the antibacterial solution is 5wt%, and the amount of hinokitiol added is 2wt% of the total amount of polyvinyl alcohol and sodium alginate, then a co-emulsifier is added, the co-emulsifier is selected as low molecular weight PVA with a degree of polymerization of 500, the amount of co-emulsifier added is 9wt% of the mass of hinokitiol, and after adding the co-emulsifier, a high-pressure homogenizer is used to cycle process 5 times at 800bar to prepare a nanodispersion; S3, the nanodispersion prepared in step S2 is mixed with the spinning solution prepared in step S1 and stirred for 30min to prepare an antibacterial spinning solution; S4, the antibacterial spinning solution is wet spun at room temperature by using a porous spinneret (pore diameter 0.1 mm, number of pores 3000) to obtain the initial coagulation fiber, and then the initial coagulation fiber is treated to obtain the bio-based blended yarn, wherein the formula of the coagulation bath in the wet spinning process is calcium chloride, water and lower alcohol (specifically ethanol) in a mass ratio of 5:47.5:47.5, and the bath temperature is controlled at 25°C, and the bath is slightly acidified by adjusting the pH to 5 with dilute acetic acid, and the single-hole linear speed during spinning is 30 m / min, the initial coagulation fiber is formed in the wet spinning coagulation bath, the initial coagulation fiber enters the deionized water washing tank at the outlet of the coagulation tank for deionized water washing to remove residual salt and solvent, and then the initial coagulation fiber is subjected to preliminary drawing at a drawing ratio of 1.5 times in a wet state, and then wet heat drawing is carried out at a drawing ratio of 2.5 times in a hot water bath at 80°C, and then heat setting is carried out, the heat setting temperature is 120°C, and then drying and winding are carried out, the surface is checked for no damage and other defects, and the bio-based blended yarn is obtained.

[0035] Example 2 A method for preparing a bio-based blended yarn, comprising the following steps: S1, sodium alginate is added to 40°C deionized water and stirred to dissolve to obtain a uniform solution, and a sodium alginate solution with a concentration of 1.5wt% is prepared, and then cooled to room temperature for standby; Polyvinyl alcohol with a number average molecular weight of 89000 is dissolved in warm water at 80°C under high-speed shearing (rotational speed) to obtain a uniform polyvinyl alcohol solution, and then cooled to 40°C for standby; The polyvinyl alcohol solution is added to the sodium alginate solution, and then a dispersing aid and a stabilizer are added, and after uniform high-speed shearing stirring, degassing (5min under vacuum), and filtering (through a 400-mesh metal filter), a spinning solution is prepared; The dispersing aid is selected from low molecular weight polyvinyl alcohol with a number average molecular weight of 25000, the stabilizer is selected from polyethylene glycol 4000, the dispersing aid is mixed with water to prepare a 0.1wt% solution for addition, the polyethylene glycol 4000 is prepared as a 0.05wt% solution for addition, the mass ratio of polyvinyl alcohol to sodium alginate is 10:90, and the concentration of the polyvinyl alcohol solution is such that the viscosity of the spinning solution is 20000mPa·s(cP); S2, the antibacterial liquid is prepared by dissolving hinokitiol in a solvent propylene glycol, the concentration of hinokitiol in the antibacterial liquid is 4wt%, the amount of hinokitiol added is 1wt% of the total amount of polyvinyl alcohol and sodium alginate, and then a co-emulsifier is added, the co-emulsifier is selected from low molecular weight PVA with a polymerization degree of 500, the amount of co-emulsifier added is 8wt% of the mass of hinokitiol, and after the addition of the co-emulsifier, the nanodispersion is prepared by circulating treatment 3 times at 800bar using a high-pressure homogenizer; S3, the nanodispersion prepared in step S2 is mixed with the spinning solution prepared in step S1 to obtain the antibacterial spinning solution; S4, the antibacterial spinning solution is wet spun at room temperature by using a porous spinneret (pore diameter 0.1 mm, number of pores 3000) to obtain the initial coagulation fiber, and then the initial coagulation fiber is treated to obtain the bio-based blended yarn, wherein the formula of the coagulation bath in the wet spinning process is calcium chloride, water and lower alcohol (specifically isopropanol) in a mass ratio of 5:40:40, and the bath temperature is controlled at 25℃, and the bath is slightly acidified by adjusting the pH to 5 with dilute acetic acid, the single-hole linear speed during spinning is 30 m / min, the initial coagulation fiber is formed in the wet spinning coagulation bath, alcohol washing is carried out after the initial coagulation fiber exits the coagulation tank to realize alcohol replacement and accelerate water replacement, and residual salt and solvent are removed, then the initial coagulation fiber is primary drawn at a draw ratio of 1.2 times in a wet state, then wet heat drawing is carried out at a draw ratio of 1.5 times in a hot water bath at 60℃, then heat setting is carried out, the heat setting temperature is 80℃, then drying and winding are carried out to obtain the bio-based blended yarn.

[0036] Example 3 A method for preparing a bio-based blended yarn, comprising the following steps: S1, sodium alginate is added to 60℃ deionized water and stirred to dissolve uniformly to obtain a sodium alginate solution with a concentration of 7.5wt%, and then cooled to room temperature for standby; Polyvinyl alcohol with a number average molecular weight of 146000 is dissolved in warm water at 80℃ under high-speed shearing (rotation speed is 2000r / min) to obtain a uniform polyvinyl alcohol solution, and then cooled to 40℃ for standby; The polyvinyl alcohol solution is added to the sodium alginate solution, and then a dispersing aid and a stabilizer are added, and after uniform high-speed shearing stirring, degassing (5min under vacuum condition) and filtering (through a 400 mesh metal filter), a spinning solution is prepared; The dispersing aid is selected from low molecular weight polyvinyl alcohol with a number average molecular weight of 35000, the stabilizer is selected from polyethylene glycol 4000, the dispersing aid is mixed with water to prepare a 0.1wt% solution for addition, the polyethylene glycol 4000 is prepared as a 0.05wt% solution for addition, the mass ratio of polyvinyl alcohol to sodium alginate is 40:60, and the concentration of the polyvinyl alcohol solution is such that the viscosity of the spinning solution is 60000mPa·s(cP); S2, the antibacterial liquid is prepared by dissolving cypressin in solvent ethanol, the concentration of cypressin in the antibacterial liquid is 8wt%, and the addition amount of cypressin is 3wt% of the sum of the addition amounts of polyvinyl alcohol and sodium alginate, then a co-emulsifier is added, the co-emulsifier is selected from low molecular weight PVA with a polymerization degree of 500, the addition amount of the co-emulsifier is 10wt% of the mass of cypressin, and after the addition of the co-emulsifier, a nano dispersion is prepared by using a high-pressure homogenizer to cycle at 800bar for 5 times; S3, the antibacterial spinning solution is prepared by mixing the nano dispersion prepared in step S2 and the spinning solution prepared in step S1; S4, the antibacterial spinning solution is wet spun at room temperature by using a porous spinneret (pore diameter 0.1 mm, number of pores 3000) to obtain the initial coagulation fiber, and the initial coagulation fiber is treated to obtain the bio-based blended yarn, wherein the formula of the coagulation bath in the wet spinning process is calcium chloride, water and low alcohol (specifically propylene glycol) in a mass ratio of 5:50:50, the bath temperature is controlled at 25°C, the bath is slightly acidified by adjusting the pH to 5 with dilute acetic acid, the single-hole linear speed during spinning is 30 m / min, the initial coagulation fiber is formed in the coagulation bath during wet spinning, the initial coagulation fiber enters the water washing tank at the outlet of the coagulation tank for deionized water washing to remove residual salt and solvent, then the initial coagulation fiber is preliminarily drawn at a draw ratio of 4.0 times in a wet state, then the initial coagulation fiber is wet heat drawn at a draw ratio of 6.0 times in a hot water bath at 120°C, then heat setting is performed, the heat setting temperature is 150°C, then drying and winding are performed to obtain the bio-based blended yarn.

[0037] Example 4 A method for preparing a bio-based blended yarn is performed according to the method in Example 1, except that 1,2-propylene glycol and acetic acid are further added to the spinning solution prepared in step S1, the addition amount of 1,2-propylene glycol is 3wt% of the spinning solution, and the addition amount of acetic acid makes the pH value of the spinning solution be 3, and the rest of the operations are the same as in Example 1.

[0038] Example 5 A method for preparing a bio-based blended yarn is performed according to the method in Example 1, except that 1,2-propylene glycol and acetic acid are further added to the spinning solution prepared in step S1, the addition amount of 1,2-propylene glycol is 2wt% of the spinning solution, and the addition amount of acetic acid makes the pH value of the spinning solution be 2, and the rest of the operations are the same as in Example 1.

[0039] Example 6 A method for preparing a bio-based blended yarn is performed according to the method in Example 1, except that 1,2-propylene glycol and acetic acid are further added to the spinning solution prepared in step S1, the addition amount of 1,2-propylene glycol is 5wt% of the spinning solution, and the addition amount of acetic acid makes the pH value of the spinning solution be 4, and the rest of the operations are the same as in Example 1.

[0040] Comparative Example 1 A method for preparing a bio-based blended yarn is performed according to the method in Example 1, except that steps S2 and S3 are not performed, and the spinning solution prepared in step S1 is directly subjected to the wet spinning step in step S4.

[0041] Comparative Example 2 A method for preparing a bio-based blended yarn is performed according to the method in Example 1, except that no low alcohol is added to the coagulation bath formula in step S4.

[0042] Performance test Firstly, the yarns prepared in the examples and comparative examples were tested for breaking strength, elongation at break, water contact angle, initial antibacterial rate (referring to GB / T 20944.3-2008 “Evaluation of antibacterial properties of textiles Part 3: oscillation method” for antibacterial rate against Staphylococcus aureus) and antibacterial rate after 50 washes (referring to 4N program in GB / T 8629-2017 “Household washing and drying procedure for testing textiles”, 50 cycles of washing were carried out, and the antibacterial performance was tested again after drying), and the test results are shown in Table 1 below.

[0043] Table 1: Table 1 (continued): The mainstream yarn at present is petroleum-based polyester fiber, which is treated with post-finishing antibacterial treatment. Specifically, the polyester filament with specification parameters of 150D / 144f is padded in a working solution containing 1.5% (owf) quaternary ammonium salt antibacterial finishing agent, with a pick-up rate of 70%, and then baked at 150°C for 2 minutes for fixation. The surface treatment method is used to achieve the antibacterial performance of the fabric. The breaking strength of the yarn prepared by this method is 4.9 cN / dtex, the elongation at break is 28%, the initial antibacterial rate is 97.5%, and the antibacterial rate after 50 washes is 38.2.

[0044] Referring to the test results in Table 1 above, it can be seen that the bio-based yarn in the present application is based on sodium alginate, and the bio-based content is 99-100%. On this basis, the present application also has excellent breaking strength and high mechanical properties, which can meet the requirements. More importantly, compared with the above-mentioned petroleum-based polyester fiber, the physical strength is close, and compared with the above-mentioned surface treated yarn, the initial antibacterial rate is equivalent, but after 50 washes, the surface coating of the surface treated yarn falls off a lot, and the antibacterial rate decreases sharply, while the antibacterial rate of the yarn prepared by the blending and encapsulation technology in the present application attenuates to a low degree, and the washable antibacterial property is more excellent. Combined with the test results of Example 4, compared with Example 1, it is treated by partial esterification, and the fiber is converted into strong hydrophobicity, which is crucial for maintaining the performance of the current thermal textile in a wet and cold environment. Combined with the test results of Comparative Example 1, the addition of the antibacterial liquid in the present application significantly improves the antibacterial performance of the yarn. Combined with the test results of Comparative Example 2, the specific coagulation bath formula helps to improve the antibacterial durability and mechanical properties of the yarn.

[0045] In addition, the continuous spinning stability, esterification degree and crystallinity of the yarns prepared by Example 1, Example 4 and Comparative Example 1 and the traditional post-finishing antibacterial treatment were also tested, and the results are shown in Table 2.

[0046] Table 2: In combination with the detection results of Table 2 above, the method of the application has stable wet spinning operation, which is helpful for industrial production.

[0047] In addition, the release amount of antibacterial active substances of the yarn in Example 1 of the application and the yarn prepared by the above conventional finishing antibacterial treatment in a simulated body fluid (SBF) (pH 7.4, Borsen BES21918KB was selected) was counted, and the statistical results are shown in Table 3 below.

[0048] Table 3: In addition, the washing residual antibacterial substance data of the yarn in Example 1 of the application and the yarn prepared by the above conventional finishing antibacterial treatment was counted, and the statistical results are shown in Table 4 below.

[0049] Table 4: Washings Example 1 Residual (%) Conventional method Residual (%) 0 100.0 100.0 5 96.8 82.5 10 94.2 68.7 15 91.8 56.3 20 89.5 45.9 25 87.3 37.2 30 85.1 29.8 40 81.2 18.7 50 77.8 12.3 In combination with the detection results of Table 3 and Table 4 above, it can be seen that the antibacterial substance of the wet spinning blending method in the application is slowly and continuously released, which meets the Higuchi diffusion model; the yarn prepared by the conventional finishing method is rapidly released at the initial stage and has a platform period at the later stage, which is mainly due to the different release mechanisms. In the application, the release of antibacterial active substances is controlled based on the swelling of the substrate, and the release rate is stable. In the conventional finishing method, surface desorption is the main method, and a large amount of antibacterial active substances is lost at the initial stage. Therefore, the yarn prepared by the application still has 77.8% of the antibacterial active substances and an antibacterial rate of 89.3% after 50 times of washing, while the yarn prepared by the conventional finishing method only has 12.3% of the active substances and the antibacterial rate is reduced to 38.2% after 50 times of washing. The yarn prepared by the application has better washing-resistant antibacterial performance.

[0050] The specific embodiments are only an explanation of the application, and are not a limitation of the application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, and the modifications are protected by the patent law as long as they are within the scope of the claims of the application.

Claims

1. A method of making a bio-based blended yarn, characterized by, The method comprises the following steps: S1, adding polyvinyl alcohol solution to sodium alginate solution, then adding dispersion aid and stabilizer, stirring uniformly, degassing, filtering, and preparing a spinning solution; S2, dissolving an antibacterial agent in a solvent to prepare an antibacterial solution, then adding an emulsifying aid and homogenizing to prepare a nanodispersion; S3, mixing the nanodispersion with the spinning solution to prepare an antibacterial spinning solution; S4, wet spinning the antibacterial spinning solution, preparing a primary coagulation fiber after post-treatment, and preparing a bio-based blended yarn, wherein the coagulation bath formula in the wet spinning process is calcium chloride, water, and a lower alcohol in a mass ratio of 5: (40-50): (40-50).

2. A process for the preparation of a bio-based blended yarn as claimed in claim 1, wherein: In step S1, the mass ratio of polyvinyl alcohol to sodium alginate is (10-40):(60-90), and the concentration of the sodium alginate solution is 1.5-7.5wt%, and the addition of the polyvinyl alcohol solution makes the viscosity of the spinning solution 20000-60000mPa·s (cP).

3. A process for the preparation of a bio-based blended yarn as claimed in claim 1, wherein: The dispersion aid is selected from low molecular weight polyvinyl alcohol, and the stabilizer is selected from polyethylene glycol 4000, and the dispersion aid is prepared as a 0.1-0.3wt% solution, and the polyethylene glycol 4000 is prepared as a 0.05-0.15wt% solution.

4. A process for the preparation of a bio-based blended yarn as claimed in claim 3, wherein: In step S1, the number average molecular weight of the polyvinyl alcohol is 89000-146000, and the number average molecular weight of the low molecular weight polyvinyl alcohol of the dispersion aid is 25000-35000.

5. The method of claim 1, wherein: In step S2, the solvent is selected from one or more of isopropyl alcohol, ethanol, and propylene glycol; The emulsifying aid is selected from one or more of low molecular weight PVA, PEG, PVP, and sodium alginate.

6. A process for preparing a bio-based blended yarn as claimed in claim 1, wherein: In step S2, the concentration of the antibacterial agent in the antibacterial solution is 4-8wt%, and the addition amount of the antibacterial agent is 1-3wt% of the sum of the addition amounts of polyvinyl alcohol and sodium alginate, and the addition amount of the emulsifying aid is 8-10wt% of the mass of the antibacterial agent, and the nanodispersion is prepared by high-pressure homogenization cycle treatment 3-5 times at 800bar.

7. A process for preparing a bio-based blended yarn as claimed in claim 1, wherein: In step S4, the post-treatment includes wet drawing and heat setting in sequence, and the wet drawing is specifically operated as follows: the primary coagulation fiber after wet spinning is first washed and then preliminarily drawn at a drawing ratio of 1.2-4.0 in a wet state, and then wet heat drawn at a drawing ratio of 1.5-6.0 in a hot water bath at 60-120℃; the heat setting temperature is 80-150℃.

8. The method of claim 1, wherein: In step S1, polyol and organic acid are also added to the prepared spinning solution, and the addition of the organic acid makes the pH value of the spinning solution 2-4, and the addition amount of the polyol is 2-5wt% of the spinning solution.

9. A biobased blended yarn, characterized by: Prepared by the method of any one of claims 1-8.

10. Use of the bio-based blended yarn of claim 9 in textile materials.

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