A bio-based spandex fiber and a method of making the same

Abstract

The application provides a bio-based spandex fiber and a preparation method thereof, and belongs to the technical field of polymer fiber materials, and aims to solve the technical problems of petrochemical resource consumption in spandex fiber preparation and uncontrollable elongation at break, low breaking strength and poor bioactivity of the bio-based spandex.The application has the following steps: dissolving diisocyanate I and bio-based polyhydric glycol in polar amine solution I, then performing pre-polymerization I to obtain a pre-polymer solution A; dissolving polyhydric glycol and diisocyanate II in polar amine solution II, then performing pre-polymerization II to obtain an isocyanate-terminated pre-polymer solution B; mixing the pre-polymer solutions A and B for reaction, then adding a natural product and continuing the reaction, and obtaining a spinning solution after maturation; and spinning the spinning solution to obtain the bio-based spandex fiber.The bio-based spandex fiber has a fineness of 5-40D, a breaking strength of 1.5-2.1 cN / detx, an elongation at break of 100-600%, and excellent biocompatibility, antibacterial property and cell regeneration promoting capacity, and can be used in medical fields such as artificial blood vessels, bone repair and wound dressings, and can also endow textiles and sanitary products with excellent health care functions, and greatly improves the added value of products.

Description

Technical Field

[0001] This invention belongs to the technical field of polymer fiber materials, and particularly relates to a bio-based spandex fiber and its preparation method. Background Technology

[0002] Spandex possesses unparalleled elasticity compared to other synthetic fibers, with a breaking elongation of up to 800% and an elastic recovery rate exceeding 95%. It is widely used in textiles, apparel, medical and health products, sports equipment, and national defense. Even a small amount added can impart excellent elasticity, comfort, and shape retention to textiles, making it an indispensable fiber material for high-end textiles. It also has extensive applications in disposable hygiene products such as diapers, protective clothing, and nursing supplies, as well as in the sports and leisure industry.

[0003] Conventional spandex is prepared by polymerization and spinning of petroleum-based polyether polyols and diisocyanates. Its molecular chain lacks biodegradable building blocks and bioactive components, which not only hinders carbon emission reduction and fails to meet the requirements of green development in the spandex industry, but also limits the application of spandex fibers in the field of medical and sanitary materials. Patent CN117127276A describes the preparation of bio-based spandex fibers by prepolymerizing, chain-extending, and spinning a polyether polyol containing a bio-based 1,3-propylene glycol structure with a conventional diisocyanate. However, because the 1,3-propylene glycol-structured polyether polyol is less flexible and structurally simpler than polytetramethylene ether glycol (PTMEG), the resulting spandex fibers have relatively low and uncontrollable elongation at break and strength, and lack bioactivity, limiting their application areas. Summary of the Invention

[0004] To address the technical problems of petrochemical resource consumption, uncontrollable elongation at break, low strength, and poor bioactivity in the preparation of spandex fibers, this invention proposes a bio-based spandex fiber and its preparation method. Through molecular structure design, a spandex fiber with both bioactivity and the excellent properties of conventional spandex is developed, meeting the application needs of high-end textiles and medical and health products, and significantly increasing the added value of products.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] A method for preparing bio-based spandex fiber, comprising the following steps:

[0007] (1) Diisocyanate I and bio-based polydiol were dissolved in polar amine solution I, and then prepolymerization reaction I was carried out to obtain prepolymer solution A;

[0008] (2) Polydiol and diisocyanate II are dissolved in polar amine solution II, and then prepolymerization reaction II is carried out to obtain isocyanate-terminated prepolymer solution B;

[0009] (3) Mix prepolymer solutions A and B at a mass ratio of 1:9-9:1 and react at 60-80℃ for 60-90 min. Then add natural products and carry out chain extension reaction for 30-60 min. After aging, obtain spinning solution; (4) Spin the spinning solution to obtain bio-based spandex fiber.

[0010] The diisocyanates I and II are independently selected from one of 4,4'-methylenebis(phenyl isocyanate), dicyclohexamethylene 4,4'-diisocyanate, toluene diisocyanate, and 4,4'-diisocyanate-3,3'-dimethylbiphenyl.

[0011] In step (1), the molar ratio of diisocyanate I to bio-based polydiol is 1:(1.5-1.8); the conditions for prepolymerization reaction I are: temperature 80-100℃, time 80-120min, to obtain solution A with a prepolymer content of 20-35wt%.

[0012] In step (2), the molar ratio of polydiol to diisocyanate II is 1:(1.8-2.5); the conditions for prepolymerization reaction II are: temperature 80-100℃, time 80-120min, to obtain a B solution with a prepolymer content of 20-35wt%.

[0013] The polar amine solutions I and II are independently selected from N,N-dimethylformamide or N,N-dimethylacetamide.

[0014] The bio-based diol is a polyether polyol, a polylactic acid diol, or a polyhydroxyacetic acid diol, and the molecular weight of the bio-based diol is 1000-3000; the polyether polyol is prepared using 1,3-propanediol, 1,5-pentanediol, and 1,4-butanediol.

[0015] The polydiol is one of polycaprolactone diol, polyethylene glycol, polycarbonate diol, and polytetrahydrofuran ether diol.

[0016] The spinning solution in step (3) also contains additives, the amount of which is 0.1-3 wt% of the total mass of the spinning solution; the additives include any one or more of antioxidants, nanoparticles, stabilizers, and flame retardants. The antioxidants are antioxidants 1010, 168, and 1135, the nanoparticles are titanium dioxide, zinc oxide, and silver, the light stabilizers are light stabilizers 770, 531, and 329, and the flame retardants are zinc borate, melamine urate, and aluminum polyphosphate.

[0017] The natural product is one or more of the following: tea polyphenols, anthocyanins, malic acid, amino acids, alginic acid, and triterpenoids, and is used in an amount of 1-10 wt% of the total amount of prepolymer solutions A and B. The chain extension reaction requires the addition of a diamine chain extender.

[0018] The spinning steps in step (4) are as follows: the spinning solution is pumped into the spinning box and extruded, the filament is solidified in the spinning channel and wound to obtain bio-based spandex fiber. The spinning conditions are that the number of filament holes is 30-200, the spinning channel is filled with hot air or hot nitrogen at 230-280℃, the gas flow rate is 0.1-3m / s, and the winding speed is 600-1500m / min.

[0019] A bio-based spandex fiber, wherein the bio-based spandex fiber has a fineness of 5-40D, a breaking strength of 1.5-2.1cN / detx, and a breaking elongation of 100-600%.

[0020] The beneficial effects of this invention are:

[0021] This invention first prepares a hydroxyl-terminated prepolymer solution A by reacting a bio-based polydiol with diisocyanate; then prepares an isocyanate-terminated prepolymer solution B by reacting a conventional polydiol with diisocyanate; by adjusting the ratio of the two, they are mixed and subjected to a chain extension reaction to impart a diblock structure to the spandex fiber; then, natural products are added for secondary chain extension and end-capping, which further increases the molecular chain length and micro-crosslinking, thereby enhancing the intermolecular forces and bioactivity, and obtaining a bio-based spandex spinning solution with a weight-average molecular weight of over 100,000. This results in excellent mechanical properties for the spandex fiber, which are adjustable and controllable within a certain range. The fineness of the bio-based spandex fiber is 5-40D, the breaking strength is 1.5-2.1cN / detx, and the breaking elongation is 100-600%.

[0022] The spandex fiber involved in this invention has excellent biocompatibility, antibacterial properties and cell regeneration promotion capabilities. It can be used in medical fields such as artificial blood vessels, bone repair, and wound dressings. It can also endow textiles and hygiene products with excellent health care functions, greatly increasing the added value of the products. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 The stress-strain curve of the bio-based spandex fiber in Example 1 is shown.

[0025] Figure 2 This is a confocal micrograph of the cytotoxicity of spandex fibers in Example 1 (green: live cells; red: dead cells) and its apparent morphology (magnification 500x).

[0026] Figure 3 Microscopic images of the surface morphology of spandex fibers in the comparative example (green: live cells; red: dead cells) at 500x magnification.

[0027] Figure 4 The infrared spectrum of the bio-based spandex fiber in Example 2 is shown.

[0028] Figure 5 The chemical structural formula of the bio-based spandex in Example 2 is shown. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Example 1

[0031] A method for preparing bio-based spandex fiber includes the following steps: 4,4'-methylenebis(phenyl isocyanate) and bio-based poly(1,3-propanediol) with a molecular weight of 1000 are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.5 and reacted at 80°C for 80 min to prepare a 30 wt% hydroxyl-terminated prepolymer solution A; polyethylene glycol and diisocyanate are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.8 and reacted at 80°C for 80 min to prepare a 30 wt% isocyanate-terminated prepolymer solution B; prepolymer solutions A and B are reacted at a mass ratio of 1:9 and 1... After reacting wt% antioxidant 1010, nano-diatomaceous earth particles, light stabilizer 770, and flame retardant melamine urate at 60℃ for 90 min, 8wt% natural product tea polyphenols and chain extender ethylenediamine were added, and the reaction continued for another 60 min. After maturation, a spinning solution was obtained. Finally, the spinning solution was pumped into the spinning box for extrusion with 60 spinnerets. The filaments were solidified in a spinning tunnel filled with 250℃ hot air at a gas flow rate of 0.1 m / s and a winding speed of 1000 m / min, resulting in bio-based spandex fibers with a fineness of 10D, a breaking strength of 1.6 cN / detx, and a breaking elongation of 190%.

[0032] Example 2

[0033] A method for preparing bio-based spandex fiber includes the following steps: 4,4'-methylenebis(phenyl isocyanate) and bio-based poly1,5-pentanediol with a molecular weight of 2000 are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.8 and reacted at 90°C for 100 min to prepare a 30 wt% hydroxyl-terminated prepolymer solution A; polyethylene glycol and dicyclohexane 4,4'-diisocyanate are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:2.5 and reacted at 100°C for 120 min to prepare a 30 wt% isocyanate-terminated prepolymer solution B; prepolymer solutions A and B are then reacted... An antioxidant 168, nanoparticle silver, stabilizer 531, and flame retardant zinc borate were reacted at 60°C for 60 min at a mass ratio of 1:9. Then, 1 wt% of natural malic acid and chain extender butanediamine were added, and the reaction continued for another 50 min. After curing, a spinning solution was obtained. Finally, the spinning solution was pumped into a spinning box and extruded with 60 spinnerets. The filaments were cured in a spinning tunnel filled with 230°C hot air at a gas flow rate of 0.15 m / s and a winding speed of 600 m / min, resulting in a bio-based spandex fiber with a fineness of 40D, a breaking strength of 1.75 cN / detx, and a breaking elongation of 600%. The bio-based spandex prepared in this example was characterized by infrared spectroscopy. Figure 4 As shown, 1750cm -1 The characteristic absorption peak of C=O is at 3430 cm⁻¹. -1 These are characteristic absorption peaks for NH, at 1510 and 1600 cm⁻¹. -1 The characteristic absorption peak of the benzene ring is at 1470 cm⁻¹. -1 The presence of a characteristic absorption peak for CH2 confirms that the prepared spandex fiber is the target product. The structural formula of the prepared bio-based ammonia is as follows: Figure 5 As shown.

[0034] Example 3

[0035] A method for preparing bio-based spandex fiber includes the following steps: 4,4'-diisocyanate-3,3'-dimethylbiphenyl and bio-based 1,3-propanediol with a molecular weight of 1500 are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.8 and reacted at 100℃ for 120 min to prepare a 30 wt% hydroxyl-terminated prepolymer solution A; polyethylene glycol and toluene diisocyanate are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.5 and reacted at 100℃ for 120 min to prepare a 30 wt% isocyanate-terminated prepolymer solution B; prepolymer solutions A and B are mixed at a mass ratio of 9:1. 1 and 2.5 wt% of antioxidant 1135, nanoparticle titanium dioxide, stabilizer 531, and flame retardant melamine urate were reacted at 80°C for 50 min. Then, 5 wt% of natural amino acids, alginic acid, and chain extender ethylenediamine were added, and the reaction was continued for 60 min. After maturation, a spinning solution was obtained. Finally, the spinning solution was pumped into the spinning box for extrusion with 60 spinnerets. The filaments were solidified in a spinning tunnel filled with 280°C hot air at a gas flow rate of 1 m / s and a winding speed of 700 m / min, resulting in bio-based spandex fibers with a fineness of 25D, a breaking strength of 1.7 cN / detx, and a breaking elongation of 185%.

[0036] Example 4

[0037] A method for preparing bio-based spandex fiber includes the following steps: Toluene diisocyanate and bio-based poly1,4-butanediol with a molecular weight of 1000 are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.5 and reacted at 80°C for 100 min to prepare a 30 wt% hydroxyl-terminated prepolymer solution A; polycarbonate diol and toluene diisocyanate are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.8 and reacted at 100°C for 120 min to prepare a 30 wt% isocyanate-terminated prepolymer solution B; prepolymer solutions A and B are mixed at a mass ratio of 4:5 and 2.5... After reacting wt% antioxidant 1010, nano-particle zinc oxide, stabilizer 770, and flame retardant aluminum polyphosphate at 80℃ for 60 min, 7wt% natural product tea polyphenols, amino acids, and chain extender propylenediamine were added, and the reaction continued for another 60 min. After maturation, a spinning solution was obtained. Finally, the spinning solution was pumped into the spinning box for extrusion with 65 spinnerets. The filaments were solidified in a spinning tunnel filled with 240℃ hot air at a gas flow rate of 0.5 m / s and a winding speed of 600 m / min, resulting in bio-based spandex fibers with a fineness of 40D, a breaking strength of 1.5 cN / detx, and a breaking elongation of 280%.

[0038] Example 5

[0039] A method for preparing bio-based spandex fiber includes the following steps: 4,4'-diisocyanate-3,3'-dimethylbiphenyl and bio-based 1,5-pentanediol with a molecular weight of 2000 are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.6 and reacted at 95°C for 110 min to prepare a 30 wt% hydroxyl-terminated prepolymer solution A; polytetrahydrofuran ether glycol and 4,4'-diisocyanate-3,3'-dimethylbiphenyl are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:2.5 and reacted at 80°C for 100 min to prepare a 30 wt% isocyanate-terminated prepolymer solution B; the prepolymer solution... A and B are reacted at 60°C for 30 min with antioxidant 1010, nano-particle silver, stabilizer 770, and flame retardant zinc borate in a mass ratio of 7:3. Then, 10 wt% of natural product alginic acid, triterpenoids, and chain extender phenylenediamine are added, and the reaction is continued for another 60 min. After maturation, a spinning solution is obtained. Finally, the spinning solution is pumped into the spinning box for extrusion with 30 spinnerets. The filaments are solidified in a spinning tunnel filled with 250°C hot air at a gas flow rate of 1 m / s and a winding speed of 1500 m / min, resulting in a bio-based spandex fiber with a fineness of 5D, a breaking strength of 1.9 cN / detx, and a breaking elongation of 310%.

[0040] Example 6

[0041] A method for preparing bio-based spandex fiber includes the following steps: 4,4'-methylenebis(phenyl isocyanate) and bio-based polylactic acid diol with a molecular weight of 1500 are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.5 and reacted at 90℃ for 110 min to prepare a 30 wt% hydroxyl-terminated prepolymer solution A; polyethylene glycol and 4,4'-methylenebis(phenyl isocyanate) are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.5 and reacted at 100℃ for 120 min to prepare a 30 wt% isocyanate-terminated prepolymer solution B; prepolymer solutions A and B are mixed at a mass ratio of 3:7... After reacting 3 wt% of antioxidant 1135, nanoparticle titanium dioxide, stabilizer 770, and flame retardant melamine urate at 80℃ for 60 min, 5 wt% of natural product alginic acid, triterpenoids, amino acids, and chain extender ethylenediamine were added, and the reaction continued for another 30 min. After maturation, a spinning solution was obtained. Finally, the spinning solution was pumped into a spinning box for extrusion with 65 spinnerets. The filaments were solidified in a spinning tunnel filled with 260℃ hot air at a gas flow rate of 0.5 m / s and a winding speed of 800 m / min, resulting in bio-based spandex fibers with a fineness of 20D, a breaking strength of 1.7 cN / detx, and a breaking elongation of 160%.

[0042] Example 7

[0043] A method for preparing bio-based spandex fiber includes the following steps: Dicyclohexane 4,4'-diisocyanate and bio-based polyhydroxyacetic acid diol with a molecular weight of 1500 are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.6 and reacted at 80℃ for 80 min to prepare a 30 wt% hydroxyl-terminated prepolymer solution A; polycaprolactone diol and dicyclohexane 4,4'-diisocyanate are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.8 and reacted at 105℃ for 100 min to prepare a 30 wt% isocyanate-terminated prepolymer solution B; prepolymer solutions A and B are mixed at a mass ratio of 1:1. After reacting 9 and 3 wt% of antioxidant 1010, nano-particle zinc oxide, stabilizer 770, and flame retardant aluminum polyphosphate at 60℃ for 60 min, 8 wt% of natural product alginic acid, triterpenoids, amino acids, and chain extender propylenediamine were added, and the reaction continued for 45 min. After aging, a spinning solution was obtained. Finally, the spinning solution was pumped into the spinning box for extrusion with 65 spinnerets. The filaments were solidified in a spinning tunnel filled with 230℃ hot air at a gas flow rate of 0.5 m / s and a winding speed of 700 m / min, resulting in bio-based spandex fibers with a fineness of 35D, a breaking strength of 1.55 cN / detx, and a breaking elongation of 220%.

[0044] Example 8

[0045] A method for preparing bio-based spandex fiber includes the following steps: Toluene diisocyanate and bio-based polylactic acid diol with a molecular weight of 1000 are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.5 and reacted at 100℃ for 120 min to prepare a 35 wt% hydroxyl-terminated prepolymer solution A; polycarbonate diol and toluene diisocyanate are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:2.5 and reacted at 80℃ for 120 min to prepare a 20 wt% isocyanate-terminated prepolymer solution B; prepolymer solutions A and B are mixed at a mass ratio of 1:9 and 0.1 wt% respectively. After t% of antioxidant 1010, nano-particle silver, stabilizer 531, and flame retardant zinc borate are fully reacted, 5wt% of natural products malic acid, alginic acid, amino acids, anthocyanins, and chain extender ethylenediamine are added, and the reaction continues for 60 minutes. After aging, a spinning solution is obtained. Finally, the spinning solution is pumped into the spinning box for extrusion with 65 spinnerets. The filaments are solidified in a spinning tunnel filled with 260°C hot nitrogen gas at a gas flow rate of 0.5 m / s and a winding speed of 1200 m / min, resulting in bio-based spandex fibers with a fineness of 7D, a breaking strength of 1.95 cN / detx, and a breaking elongation of 210%.

[0046] Example 9

[0047] A method for preparing bio-based spandex fiber includes the following steps: 4,4'-methylenebis(phenyl isocyanate) and 1000-molecular-weight bio-based poly(1,4-butanediol) are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.8 and reacted at 80°C for 80 min to prepare a 20 wt% hydroxyl-terminated prepolymer solution A; polyethylene glycol and 4,4'-methylenebis(phenyl isocyanate) are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:2 and reacted at 120°C for 120 min to prepare a 35 wt% isocyanate-terminated prepolymer solution B; prepolymer solutions A and B are reacted at a mass ratio of 1:9... After reacting 3 wt% antioxidant 1135, nano-particle silver, stabilizer 531, flame retardant melamine urate, and aluminum polyphosphate at 75°C for 60 min, 8 wt% natural malic acid, alginic acid, and chain extender ethylenediamine were added, and the reaction continued for another 60 min. After maturation, a spinning solution was obtained. Finally, the spinning solution was pumped into the spinning box for extrusion with 60 spinnerets. The filaments were solidified in a spinning tunnel filled with 230°C hot air at a gas flow rate of 0.5 m / s and a winding speed of 600 m / min, resulting in bio-based spandex fibers with a fineness of 25D, a breaking strength of 1.5 cN / detx, and a breaking elongation of 495%.

[0048] Example 10

[0049] A method for preparing bio-based spandex fiber includes the following steps: 4,4'-diisocyanate-3,3'-dimethylbiphenyl and bio-based poly(1,4-butanediol) with a molecular weight of 1000 are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.5 and reacted at 80°C for 80 min to prepare a 30 wt% hydroxyl-terminated prepolymer solution A; polyethylene glycol and 4,4'-diisocyanate-3,3'-dimethylbiphenyl are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.8 and reacted at 120°C for 120 min to prepare a 20 wt% isocyanate-terminated prepolymer solution B; prepolymer solution A is then reacted with… B is prepared by reacting antioxidant 1010, nano-particle titanium dioxide, stabilizer 770, and flame retardant zinc borate at 80°C for 40 min in a 9:1 ratio with 0.5 wt% of these components. Then, 10 wt% of natural malic acid, alginic acid, and chain extender butanediamine are added, and the reaction continues for another 30 min. After maturation, a spinning solution is obtained. Finally, the spinning solution is pumped into a spinning box and extruded with 60 spinnerets. The filaments are solidified in a spinning tunnel filled with 280°C hot nitrogen at a gas flow rate of 0.5 m / s and a winding speed of 800 m / min, resulting in a bio-based spandex fiber with a fineness of 25D, a breaking strength of 2.1 cN / detx, and a breaking elongation of 100%.

[0050] Comparative Example 1

[0051] A method for preparing an spandex fiber includes the following steps: 4,4'-methylenebis(phenyl isocyanate) and polytetrahydrofuran ether with a molecular weight of 1000 are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.5 and reacted at 80°C for 80 min to prepare a 30 wt% hydroxyl-terminated prepolymer solution A; polyethylene glycol and 4,4'-methylenebis(phenyl isocyanate) are dissolved in N,N-dimethylacetamide solution at a molar ratio of 1:1.5 and reacted at 80°C for 80 min to prepare a 30 wt% isocyanate-terminated prepolymer solution. B; Prepolymer solutions A and B are reacted at 60°C for 90 min with 1 wt% antioxidant 1010, nano-diatomaceous earth particles, light stabilizer 770, flame retardant melamine urate, and chain extender ethylenediamine at a mass ratio of 1:9. Finally, the spinning solution is pumped into the spinning box for extrusion with 60 spinnerets. The filaments are solidified in a spinning tunnel filled with 230°C hot air at a gas flow rate of 0.1 m / s and a winding speed of 600 m / min to obtain spandex fibers with a fineness of 20D, a breaking strength of 1.1 cN / detx, and a breaking elongation of 520%.

[0052] The biocompatibility of the spandex fibers prepared in Example 1 and Comparative Example 1 was tested, and the results are as follows: Figure 2 and 3 As shown, it is clear that the comparative fiber, after cell culture, has a large number of red dead cells in its fluorescence micrograph, while no dead cells were clearly observed in the fiber of Example 1, indicating that the fiber of Example 1 has excellent biocompatibility.

[0053] Biocompatibility test conditions: Sterilized fibers were cultured with HUVEC cells for 72 hours, washed with PBS buffer, stained with staining solution, and then the cell morphology was observed under a fluorescence microscope.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing bio-based spandex fiber, characterized in that, The steps are as follows: (1) Dissolve diisocyanate I and bio-based polydiol in polar amine solution I, and then carry out prepolymerization reaction I to obtain prepolymer solution A; (2) Polydiol and diisocyanate II are dissolved in polar amine solution II, and then prepolymerization reaction II is carried out to obtain isocyanate-terminated prepolymer solution B; (3) Mix prepolymer solutions A and B and react them. Then add natural products and continue the reaction. After aging, obtain spinning solution. (4) The spinning solution was spun to obtain bio-based spandex fiber; In step (1), the molar ratio of diisocyanate I to bio-based polydiol is 1:(1.5-1.8); the conditions for prepolymerization reaction I are: temperature 80-100℃, time 80-120min, to obtain solution A with a prepolymer content of 20-35wt%. The polar amine solutions I and II are independently selected from N,N-dimethylformamide or N,N-dimethylacetamide; in step (3), the mass ratio of prepolymer solutions A to B is (1:9)-(9:1), the mixing reaction temperature is 60-80℃, the time is 60-90min, and the chain extension reaction is carried out for 30-60min after adding the natural product; The natural product mentioned is one or more of tea polyphenols, anthocyanins, alginic acid, and triterpenoids, and the amount used is 1-10 wt% of the total amount of prepolymer solutions A and B; In step (2), the molar ratio of polydiol to diisocyanate II is 1:(1.8-2.5); the conditions for prepolymerization reaction II are: temperature 80-100℃, time 80-120min, to obtain a B solution with a prepolymer content of 20-35wt%. The bio-based polydiol is a polyether polyol, polylactic acid diol, or polyhydroxyacetic acid diol, and the molecular weight of the bio-based polydiol is 1000-3000. The polyether polyol was prepared using 1,3-propanediol, 1,5-pentanediol, and 1,4-butanediol. The polydiol is one of polycaprolactone diol, polyethylene glycol, polycarbonate diol, and polytetrahydrofuran ether diol; The bio-based spandex fiber prepared according to the above method has a fineness of 5-40D, a breaking strength of 1.5-2.1cN / dtex, and a breaking elongation of 100-600%.

2. The method for preparing bio-based spandex fiber according to claim 1, characterized in that, The diisocyanates I and II are independently selected from one of 4,4'-methylenebis(phenyl isocyanate), dicyclohexamethylene-4,4'-diisocyanate, toluene diisocyanate, and 4,4'-diisocyanate-3,3'-dimethylbiphenyl.

3. The method for preparing bio-based spandex fiber according to any one of claims 1-2, characterized in that, The spinning solution in step (3) also contains an auxiliary agent, the amount of which is 0.1-3 wt% of the total mass of the spinning solution; the auxiliary agent includes any one or more of antioxidants, nanoparticles, stabilizers, and flame retardants.

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