A kind of carbon dioxide based polyurethane fiber and preparation method thereof

Abstract

A carbon dioxide-based polyurethane fiber and a preparation method thereof, belonging to the technical field of fiber materials. The component of the polyurethane fiber is a carbon dioxide-based polyurethane with a molecular weight Mn of 2000 to 8000; the carbon dioxide-based polyurethane is polymerized by carbon dioxide-based polycarbonate polyol and isocyanate, the molecular chain of the carbon dioxide-based polycarbonate polyol contains polycarbonate segments, polyether segments and any PE segments arranged randomly or in blocks, the molar percentage of PEC repeating units in the repeating units of the polycarbonate segments is more than 50%, and the PEC repeating units are copolymerized units of ethylene oxide and carbon dioxide. The present invention directly uses carbon dioxide-based polyurethane with a specific molecular weight as a fiber raw material, which is easier to color, has good hydrophilicity, and has a soft hand feel.

Description

Technical Field

[0001] The invention discloses a carbon dioxide-based polyurethane fiber and a preparation method thereof, belonging to the technical field of fiber materials. Background Art

[0002] Polyurethane fiber is a synthetic fiber made of polyurethane by dry spinning or wet spinning. Polyurethane fiber is the abbreviation of polyurethane fiber, also known as polyurethane elastic fiber, called spandex in China, with high elastic recovery rate and high elongation at break similar to rubber filaments. Its elastic elongation reaches 400%~700%, and when the elongation is 500%~600%, the elastic recovery rate is 97%~98%, but the strength is relatively low, only 8.8cN / dtex.

[0003] Chinese patent CN118272957A discloses a carbon dioxide-based polycarbonate fiber, which is mainly made of a semi-aromatic polycarbonate copolymer containing lactide, and modified by adding toughening agents, softeners and other additives to successfully produce carbon dioxide-based fibers. However, the polycarbonate material itself has strong rigidity, and a toughening agent needs to be added to adjust the toughness, and the flexibility is improved by adding a softener, but the blending of multiple materials reduces the strength of the fiber. And this blended material also has shortcomings in colorability. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a carbon dioxide-based polyurethane fiber with better strength and easy coloring and a preparation method thereof.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a carbon dioxide-based polyurethane fiber, characterized in that the component is a carbon dioxide-based polyurethane, the carbon dioxide-based polyurethane is polymerized by carbon dioxide-based polycarbonate polyol and isocyanate, wherein the molecular weight Mn of the carbon dioxide-based polycarbonate polyol is between 2000 and 8000; the molecular chain of the carbon dioxide-based polycarbonate polyol comprises polycarbonate segments, polyether segments and any PE segments arranged randomly or in blocks, the molar percentage of PEC repeating units in the repeating units of the polycarbonate segments is above 50%, and the PEC repeating units are copolymerized units of ethylene oxide and carbon dioxide.

[0006] The present invention is a TPU fiber, which directly uses a carbon dioxide-based polyurethane with a specific molecular weight as a fiber raw material. This TPU has good fiber strength. More than 50% of the TPU molecular chains made into fibers in the present invention are PEC repeating units, thereby controlling the oxygen atom content in the fibers, making the TPU fibers easier to color, good in hydrophilicity, and soft in feel.

[0007] Preferably, in the above-mentioned carbon dioxide-based polyurethane fiber, the comonomer of the carbon dioxide-based polycarbonate polyol is a chain transfer agent, an epoxy compound, carbon dioxide and any aromatic anhydride, and the epoxy compound is a mixture of ethylene oxide and other alkylene oxides. More preferably, the other alkylene oxides are long-chain alkylene oxides, such as 1,2-epoxydecane, 1,2-epoxypentadecane, 1,2-epoxyheptadecane or 1,2-epoxynonadecane. In the comonomer of the carbon dioxide-based polycarbonate polyol used in TPU, the epoxy compound used is a mixture of ethylene oxide and long-chain alkylene oxides. Adding long-chain alkylene oxides can increase the restraint between molecular chains, thereby improving the toughness of the produced fiber.

[0008] Preferably, the aromatic anhydride in the carbon dioxide-based polycarbonate polyol is phthalic anhydride or naphthalene anhydride. Adding phthalic anhydride or naphthalene anhydride to the comonomer of the carbon dioxide-based polycarbonate polyol used in TPU can improve the temperature resistance of the produced fiber.

[0009] Preferably, the chain transfer agent in the carbon dioxide-based polycarbonate polyol is a C2-C15 diol, such as diethylene glycol, triethylene glycol, propylene glycol, butanediol, pentanediol or hexanediol or bisphenol A. When diol is used as the chain transfer agent, the molecular chain of the obtained TPU is linear, which is easier to make into fiber bundles. More preferably, aromatic diol is used, and the strength of the obtained TPU fiber is higher.

[0010] Preferably, the epoxy compound in the carbon dioxide-based polycarbonate polyol is a mixture of ethylene oxide and long-chain alkylene oxide in a molar ratio of 6-10:1-4. Adding an appropriate amount of long-chain alkylene oxide can improve the entanglement between molecular chains and the toughness of the prepared fiber without causing excessive rigidity of the fiber and affecting the soft feel of the fiber.

[0011] Preferably, the molar ratio of the polycarbonate segment, the polyether segment and the PE segment in the carbon dioxide-based polycarbonate polyol is 60-90:10-30:0-10. Under the preferred segment ratio, the oxygen content in the molecular chain can better ensure that the TPU fiber is easier to color and has good hydrophilicity, and maintains a soft feel while having good strength.

[0012] Preferably, in the carbon dioxide-based polyurethane fiber, the isocyanate is an aromatic diisocyanate. The fiber obtained by using the aromatic diisocyanate has better temperature resistance. Specifically, the aromatic diisocyanate includes diphenylmethane diisocyanate, toluene diisocyanate or meta-xylylene diisocyanate.

[0013] A method for preparing the above-mentioned carbon dioxide-based polyurethane fiber comprises directly drawing or spinning the carbon dioxide-based polyurethane through a spinning mechanism to form primary fibers; stretching the primary fibers; and placing the stretched fibers in hot air for curing to obtain carbon dioxide-based polyurethane fibers.

[0014] The preparation method of the TPU fiber is basically similar to the conventional fiber preparation method, and only the post-processing process needs to be adjusted. The present invention uses carbon dioxide-based polyurethane as the fiber material, which has a faster curing speed, high production efficiency during fiber preparation, and reduced production costs.

[0015] Preferably, in the above-mentioned method for preparing carbon dioxide-based polyurethane fibers, the set temperature of the drawing is 170° C. to 230° C., and the set temperature of the spinning is 200° C. to 230° C. The set drawing or spinning temperature can maintain a suitable melt viscosity during the fiber preparation process, help improve the tensile properties and uniformity of the fiber, and at the same time improve the working efficiency of the spinning mechanism and accelerate the formation of the fiber.

[0016] Preferably, in the method for preparing the carbon dioxide-based polyurethane fiber, the stretching temperature during the stretching treatment is set at 55°C to 75°C, and the stretching ratio is controlled at 5 to 20 times. The obtained spun fiber is subjected to appropriate stretching treatment to better enhance its molecular arrangement and crystallinity, thereby improving the strength and tensile properties of the fiber. More preferably, the stretching ratio is controlled at 7 to 10 times.

[0017] Preferably, in the preparation method of the carbon dioxide-based polyurethane fiber, the temperature of the hot air during the curing treatment is 85°C to 95°C, and the relative humidity of the hot air is controlled at 15% to 25%. The TPU fiber with a high PEC content of the present invention has a faster curing rate and good flexibility. It can be cured at a higher temperature. The stretched fiber is placed at an appropriate temperature for rapid curing to finally form a TPU fiber.

[0018] Compared with the prior art, a carbon dioxide-based polyurethane fiber and a preparation method thereof of the present invention have the following beneficial effects: the TPU fiber of the present invention directly uses a carbon dioxide-based polyurethane of a specific molecular weight as a raw material. The obtained TPU fiber has excellent strength, wherein more than 50% of the molecular chains contain PEC repeating units, aiming to control the oxygen atom content to achieve better colorability, excellent hydrophilicity and soft feel of the fiber. In the carbon dioxide-based polycarbonate polyol comonomer used, ethylene oxide and long-chain alkylene oxide are mixed, and the addition of long-chain alkylene oxide can enhance the restraint between molecular chains and improve the toughness of the fiber. The use of diols as chain transfer agents can generate linear TPU molecular chains, which is beneficial to the preparation of fiber bundles. By optimizing the segment ratio, the colorability and hydrophilicity of the fiber can be effectively ensured while maintaining good strength, while maintaining the soft feel of the fiber. In combination with aromatic diisocyanates, fibers with better high temperature resistance can be produced. DETAILED DESCRIPTION

[0019] The present invention is described in detail below by way of examples. Unless otherwise specified, the raw materials used are commercially available.

[0020] Example 1

[0021] Preparation of carbon dioxide-based polycarbonate polyol: epoxy compound, phthalic anhydride, bisphenol A and catalyst are added to the reactor at a molar ratio of 49:1:1:0.005, wherein the catalyst is a composite catalyst of triethyl boron and tetra-n-butyl ammonium iodide at a molar ratio of 1:1.3, and the epoxy compound is a mixture of ethylene oxide and 1,2-epoxyheptadecane at a molar ratio of 8:2. Carbon dioxide is charged to 2.5MPa, and the temperature is raised to 55°C for copolymerization for 15h. The molar ratio of carbon dioxide consumption to bisphenol A input is 43:1. After the reaction is terminated, the material is discharged, and the number average molecular weight of the obtained carbon dioxide-based polycarbonate polyol is detected to be 6300. Further, by nuclear magnetic resonance, the molar percentage of the polycarbonate segment repeating unit is 85.7%, the molar percentage of the polyether segment repeating unit is 12.3%, and the molar percentage of the PE segment repeating unit is 2%.

[0022] Preparation of TPU: 55 parts of the obtained carbon dioxide-based polycarbonate polyol and 60 parts of diphenylmethane diisocyanate are mixed by weight, reacted at 70°C for 3 hours, then the material is placed in a mold at 110°C, and 0.1 parts of 1,4-butanediol and 0.05 parts of stannous octoate as a catalyst are added, stirred and mixed, heat cured at 120°C for 1 hour, then placed in a blower dryer, vulcanized at 100°C for 12 hours, and finally left at room temperature for 5 days to obtain carbon dioxide-based polyurethane.

[0023] The carbon dioxide-based polyurethane is added into a twin-screw extruder, the outlet temperature of the extruder is set at 175°C, the material is melted, filtered and extruded, the extruded material is transferred to a fiber drawing machine for drawing, the drawing temperature is 180°C, and cooled to form nascent fibers; the nascent fibers are stretched, the stretching temperature is set at 65°C, and the stretching multiple is controlled at 8 times; the stretched fibers are placed in hot air at a relative humidity of 20% and a temperature of 90°C for curing to obtain carbon dioxide-based polyurethane fibers.

[0024] Example 2

[0025] Preparation of carbon dioxide-based polycarbonate polyol: epoxy compound, phthalic anhydride, bisphenol A and catalyst are added to the reactor at a molar ratio of 46:4.2:1:0.005, wherein the catalyst is a composite catalyst of triethyl boron and tetra-n-butyl ammonium iodide at a molar ratio of 1:1.8, and the epoxy compound is a mixture of ethylene oxide and 1,2-epoxypentadecane at a molar ratio of 10:1. Carbon dioxide is charged to 2.5MPa, and the temperature is raised to 50°C for copolymerization for 15h. The molar ratio of carbon dioxide consumption to bisphenol A input is 36:1. After the reaction is terminated, the material is discharged, and the number average molecular weight of the obtained carbon dioxide-based polycarbonate polyol is detected to be 4500. Further, by nuclear magnetic resonance, the molar percentage of the polycarbonate segment repeating unit is 72.1%, the molar percentage of the polyether segment repeating unit is 19.7%, and the molar percentage of the PE segment repeating unit is 8.1%.

[0026] Preparation of TPU: 55 parts of the obtained carbon dioxide-based polycarbonate polyol and 60 parts of diphenylmethane diisocyanate are mixed by weight, reacted at 70°C for 3 hours, then the material is placed in a mold at 110°C, and 0.1 parts of 1,4-butanediol and 0.05 parts of stannous octoate as a catalyst are added, stirred and mixed, heat cured at 120°C for 1 hour, then placed in a blower dryer, vulcanized at 100°C for 12 hours, and finally left at room temperature for 5 days to obtain carbon dioxide-based polyurethane.

[0027] The carbon dioxide-based polyurethane is added into a twin-screw extruder, the outlet temperature of the extruder is set at 170°C, the material is melted, filtered and extruded, the extruded material is transferred to a fiber drawing machine for drawing, the drawing temperature is 180°C, and cooled to form nascent fibers; the nascent fibers are stretched, the stretching temperature is set at 65°C, and the stretching multiple is controlled at 10 times; the stretched fibers are placed in hot air at a relative humidity of 20% and a temperature of 90°C for curing to obtain carbon dioxide-based polyurethane fibers.

[0028] Example 3

[0029] Preparation of carbon dioxide-based polycarbonate polyol: add epoxy compound, bisphenol A and catalyst into the reactor at a molar ratio of 50:1:0.005, wherein the catalyst is a composite catalyst of triethyl boron and tetra-n-butyl ammonium iodide at a molar ratio of 1:1.5, and the epoxy compound is a mixture of ethylene oxide and 1,2-epoxydecane at a molar ratio of 6:4. Fill with carbon dioxide to 2.5MPa, heat to 50°C for copolymerization for 16h, and the molar ratio of carbon dioxide consumption to bisphenol A input is 40:1. After terminating the reaction, discharge the material, and detect that the number average molecular weight of the obtained carbon dioxide-based polycarbonate polyol is 6200. Further nuclear magnetic resonance detection shows that the molar percentage of polycarbonate segment repeating units is 80.1%, and the molar percentage of polyether segment repeating units is 19.9%.

[0030] Preparation of polyurethane: 55 parts of the obtained polyether diol and 65 parts of toluene diisocyanate are mixed by weight, reacted at 70°C for 3 hours, then the materials are placed in a mold at 110°C, and 0.1 parts of 1,4-butanediol and 0.05 parts of stannous octoate as a catalyst are added, stirred and mixed, heat cured at 120°C for 1 hour, then placed in a blower dryer, vulcanized at 100°C for 12 hours, and finally left at room temperature for 5 days to obtain carbon dioxide-based polyurethane.

[0031] The carbon dioxide-based polyurethane is added into a twin-screw extruder, the outlet temperature of the extruder is set at 170°C, the material is melted, filtered and extruded, the extruded material is transferred to a fiber drawing machine for drawing, the drawing temperature is 80°C, and cooled to form nascent fibers; the nascent fibers are stretched, the stretching temperature is set at 65°C, and the stretching multiple is controlled at 7 times; the stretched fibers are placed in hot air at a relative humidity of 20% and a temperature of 90°C for curing to obtain carbon dioxide-based polyurethane fibers.

[0032] Example 4

[0033] Preparation of carbon dioxide-based polycarbonate polyol: epoxy compound, phthalic anhydride, propylene glycol and catalyst are added to the reactor at a molar ratio of 49:1:1:0.005, wherein the catalyst is a composite catalyst of triethyl boron and tetra-n-butyl ammonium iodide at a molar ratio of 1:1.3, and the epoxy compound is a mixture of ethylene oxide and 1,2-epoxyheptadecane at a molar ratio of 8:2. Carbon dioxide is charged to 2.5MPa, and the temperature is raised to 55°C for copolymerization for 15h. The molar ratio of carbon dioxide consumption to propylene glycol input is 44:1. After the reaction is terminated, the material is discharged, and the number average molecular weight of the obtained carbon dioxide-based polycarbonate polyol is detected to be 6300. Further, by nuclear magnetic resonance, the molar percentage of the polycarbonate segment repeating unit is 86.1%, the molar percentage of the polyether segment repeating unit is 12.4%, and the molar percentage of the PE segment repeating unit is 1.5%.

[0034] Preparation of TPU: 55 parts of the obtained carbon dioxide-based polycarbonate polyol and 60 parts of diphenylmethane diisocyanate are mixed by weight, reacted at 70°C for 3 hours, then the material is placed in a mold at 110°C, and 0.1 parts of 1,4-butanediol and 0.05 parts of stannous octoate as a catalyst are added, stirred and mixed, heat cured at 120°C for 1 hour, then placed in a blower dryer, vulcanized at 100°C for 12 hours, and finally left at room temperature for 5 days to obtain carbon dioxide-based polyurethane.

[0035] The carbon dioxide-based polyurethane is added into a twin-screw extruder, the outlet temperature of the extruder is set at 175°C, the material is melted, filtered and extruded, the extruded material is transferred to a fiber drawing machine for drawing, the drawing temperature is 180°C, and cooled to form nascent fibers; the nascent fibers are stretched, the stretching temperature is set at 65°C, and the stretching multiple is controlled at 8 times; the stretched fibers are placed in hot air at a relative humidity of 20% and a temperature of 90°C for curing to obtain carbon dioxide-based polyurethane fibers.

[0036] Example 5

[0037] Preparation of carbon dioxide-based polycarbonate polyol: epoxy compound, phthalic anhydride, bisphenol A and catalyst are added to the reactor in a molar ratio of 49:1:1:0.005, wherein the catalyst is a composite catalyst of triethyl boron and tetra-n-butyl ammonium iodide in a molar ratio of 1:1.3, and the epoxy compound is a mixture of ethylene oxide and propylene oxide in a molar ratio of 8:2. Carbon dioxide is charged to 2.5MPa, and the temperature is raised to 55°C for copolymerization for 15h. The molar ratio of carbon dioxide consumption to bisphenol A input is 43:1. After the reaction is terminated, the material is discharged, and the number average molecular weight of the obtained carbon dioxide-based polycarbonate polyol is detected to be 6300. Further, by nuclear magnetic resonance detection, the molar percentage of polycarbonate segment repeating units is 85.9%, the molar percentage of polyether segment repeating units is 12.1%, and the molar percentage of PE segment repeating units is 2.0%.

[0038] Preparation of TPU: 55 parts of the obtained carbon dioxide-based polycarbonate polyol and 60 parts of diphenylmethane diisocyanate are mixed by weight, reacted at 70°C for 3 hours, then the material is placed in a mold at 110°C, and 0.1 parts of 1,4-butanediol and 0.05 parts of stannous octoate as a catalyst are added, stirred and mixed, heat cured at 120°C for 1 hour, then placed in a blower dryer, vulcanized at 100°C for 12 hours, and finally left at room temperature for 5 days to obtain carbon dioxide-based polyurethane.

[0039] The carbon dioxide-based polyurethane is added into a twin-screw extruder, the outlet temperature of the extruder is set at 175°C, the material is melted, filtered and extruded, the extruded material is transferred to a fiber drawing machine for drawing, the drawing temperature is 180°C, and cooled to form nascent fibers; the nascent fibers are stretched, the stretching temperature is set at 65°C, and the stretching multiple is controlled at 8 times; the stretched fibers are placed in hot air at a relative humidity of 20% and a temperature of 90°C for curing to obtain carbon dioxide-based polyurethane fibers.

[0040] Example 6

[0041] Preparation of carbon dioxide-based polycarbonate polyol: add epoxy compound, phthalic anhydride, butanediol and catalyst in a molar ratio of 18:2:1:0.004 to the reactor, wherein the catalyst is a composite catalyst of triethyl boron and tetra-n-butyl ammonium iodide in a molar ratio of 1:0.8, and the epoxy compound is a mixture of ethylene oxide and 1,2-epoxydecane in a molar ratio of 8:2. Fill with carbon dioxide to 1.2MPa, heat to 60°C for copolymerization for 15h, and the molar ratio of carbon dioxide consumption to butanediol input is 12:1. After terminating the reaction, discharge the material, and detect that the number average molecular weight of the obtained carbon dioxide-based polycarbonate polyol is 2000. Further, by nuclear magnetic resonance, the molar percentage of the polycarbonate segment repeating unit is 60%, the molar percentage of the polyether segment repeating unit is 30%, and the molar percentage of the PE segment repeating unit is 10%.

[0042] Preparation of polyurethane: 55 parts of the obtained polyether diol, 50 parts of diphenylmethane diisocyanate, toluene diisocyanate or meta-xylylene diisocyanate are mixed by weight, reacted at 65°C for 4 hours, then the materials are placed in a mold at 115°C, and 0.15 parts of 1,4-butanediol and 0.03 parts of stannous octoate as a catalyst are added, stirred and mixed, heat cured at 120°C for 1 hour, then placed in a blast dryer, vulcanized at 90°C for 15 hours, and finally left at room temperature for 5 days to obtain a carbon dioxide-based polyurethane.

[0043] The carbon dioxide-based polyurethane is added into a twin-screw extruder, the outlet temperature of the extruder is set at 175°C, the material is melted, filtered and extruded, the extruded material is transferred to a fiber drawing machine for drawing, the drawing temperature is 185°C, and cooled to form nascent fibers; the nascent fibers are stretched, the stretching temperature is set at 75°C, and the stretching multiple is controlled at 20 times; the stretched fibers are placed in hot air at a relative humidity of 25% and a temperature of 95°C for curing to obtain carbon dioxide-based polyurethane fibers.

[0044] Example 7

[0045] Preparation of carbon dioxide-based polycarbonate polyol: Add epoxy compound, bisphenol A and catalyst into the reactor at a molar ratio of 50:1:0.008, wherein the catalyst is a composite catalyst of triethyl boron and tetra-n-butyl ammonium iodide at a molar ratio of 1:2, and the epoxy compound is a mixture of ethylene oxide and 1,2-epoxynonadecane at a molar ratio of 7:3. Fill with carbon dioxide to 2.5MPa, heat to 55°C for copolymerization for 17h, and the molar ratio of carbon dioxide consumption to bisphenol A input is 45:1. After terminating the reaction, discharge the material, and detect that the number average molecular weight of the obtained carbon dioxide-based polycarbonate polyol is 8000. Further, nuclear magnetic resonance detection shows that the molar percentage of polycarbonate segment repeating units is 90%, and the molar percentage of polyether segment repeating units is 10%.

[0046] Preparation of polyurethane: 45 parts of the obtained polyether diol, diphenylmethane diisocyanate, toluene diisocyanate or meta-xylyl isocyanate are mixed by weight, reacted at 75°C for 2.5 hours, then the material is placed in a mold at 105°C, and 0.1 parts of 1,4-butanediol and 0.05 parts of stannous octoate as a catalyst are added, stirred and mixed, heat cured at 120°C for 1 hour, then placed in a blast dryer, vulcanized at 100°C for 12 hours, and finally left at room temperature for 5 days to obtain a carbon dioxide-based polyurethane.

[0047] The carbon dioxide-based polyurethane is added into a twin-screw extruder, the outlet temperature of the extruder is set at 170°C, the material is melted, filtered and extruded, the extruded material is transferred to a fiber drawing machine for drawing, the drawing temperature is 175°C, and it is cooled to form nascent fibers; the nascent fibers are stretched, the stretching temperature is set at 55°C, and the stretching multiple is controlled at 5 times; the stretched fibers are placed in hot air with a relative humidity of 15% and a temperature of 85°C for curing to obtain carbon dioxide-based polyurethane fibers.

[0048] The performance test results of the carbon dioxide-based polyurethane fibers obtained in various examples are shown in Table 1.

[0049] Table 1 Performance test results

[0050] .

[0051] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A carbon dioxide-based polyurethane fiber, characterized in that: The composition is a carbon dioxide-based polyurethane with a molecular weight Mn of 2000 to 8000; The carbon dioxide-based polyurethane is polymerized by carbon dioxide-based polycarbonate polyol and isocyanate, the molecular chain of the carbon dioxide-based polycarbonate polyol comprises polycarbonate segments, polyether segments and any PE segments arranged randomly or in blocks, the molar percentage of PEC repeating units in the repeating units of the polycarbonate segments is more than 50%, and the PEC repeating units are copolymerized units of ethylene oxide and carbon dioxide; The comonomers of the carbon dioxide-based polycarbonate polyol are chain transfer agents, epoxy compounds, carbon dioxide and any aromatic anhydride, the epoxy compounds are a mixture of ethylene oxide and long-chain alkylene oxides, the chain transfer agent is a C2-C15 diol, and the epoxy compounds are a mixture of ethylene oxide and long-chain alkylene oxides in a molar ratio of 5-10:1-5; The molar ratio of the polycarbonate segment, the polyether segment and the PE segment is 60~90﹕10~30﹕0~10.

2. A carbon dioxide-based polyurethane fiber according to claim 1, characterized in that: The isocyanate is an aromatic diisocyanate.

3. A carbon dioxide-based polyurethane fiber according to claim 2, characterized in that: The aromatic diisocyanate includes diphenylmethane diisocyanate, toluene diisocyanate or meta-xylylene diisocyanate.

4. A method for preparing the carbon dioxide-based polyurethane fiber according to any one of claims 1 to 3, characterized in that: The carbon dioxide-based polyurethane is directly drawn or spun through a spinning mechanism to form primary fibers; the primary fibers are stretched; and the stretched fibers are placed in hot air for curing to obtain carbon dioxide-based polyurethane fibers.

5. The method for preparing a carbon dioxide-based polyurethane fiber according to claim 4, characterized in that: The setting temperature of the wire drawing is 175°C-185°C, and the setting temperature of the wire spinning is 200°C-210°C.

6. The method for preparing a carbon dioxide-based polyurethane fiber according to claim 4, characterized in that: During the stretching treatment, the stretching temperature is set at 55° C. to 75° C., and the stretching multiple is controlled at 5 to 20 times.