Bio-based low-carbon environment-friendly functional furan polyester fiber and preparation method thereof

Abstract

The invention discloses a bio-based low-carbon environment-friendly functional furan polyester fiber and a preparation method thereof. The invention belongs to the technical field of macromolecules, and particularly relates to a polyfurandicarboxylic acid cyclohexanedimethanol-ethylene glycol copolyester fiber. The invention also provides a preparation method of the bio-based furan copolyester, and the bio-based furan copolyester obtained according to the preparation method provided by the invention has higher crystallinity and crystallization rate, excellent fiber mechanical properties and remarkable antibacterial property, and is a sustainable environment-friendly fiber with good comprehensive properties. The bio-based furan copolyester fiber and the like can be widely applied to the related fields of conventional clothes, home textiles and the like.

Description

Technical Field

[0001] This invention belongs to the field of furan polyester fiber technology, specifically relating to a bio-based low-carbon environmentally friendly functional furan polyester fiber and its preparation method. Background Technology

[0002] 2,5-Furandicarboxylic acid (FDCA) is a stable biomass monomer with a structure similar to terephthalic acid (PTA), both having a cyclic conjugated system. Furan polyester synthesized from FDCA as a dicarboxylic acid and diol also has excellent comprehensive properties, while eliminating dependence on petroleum-based feedstocks.

[0003] Polyethylene 2,5-furandicarboxylate (PEF) is prepared by melt polymerization of 2,5-furandicarboxylic acid and ethylene glycol. Compared with polyethylene terephthalate (PET), it has higher mechanical strength, glass transition temperature, and barrier properties. However, in fiber applications, due to the high rigidity of PEF molecular chains, molecular chain movement is difficult and the crystallization rate is slow, resulting in excessive modulus and heat shrinkage of filament fibers. This causes certain problems in hand feel and subsequent weaving and dyeing processes. Therefore, it is necessary to optimize and improve the hand feel and crystallization properties of PEF to better meet application requirements.

[0004] 1,4-Cyclohexanediethanol (CHDM) is an important alicyclic diol with a prominent saturated six-membered carbon ring structure. However, it is not in the same plane but adopts a lower-energy chair conformation. This structural feature allows it to coordinate well with the furan ring, resulting in high crystallinity and crystallization rate. At the same time, the most significant and important structural feature of CHDM is that, due to the presence of the cyclohexane ring, the two hydroxymethyl groups have different spatial orientations, resulting in two stereoisomers. In this invention, it is proposed that CHDM with a trans proportion higher than 70% can be used to prepare a high-performance furan copolyester fiber.

[0005] Therefore, the development and application of furan-based polyester fibers not only requires solving problems such as poor raw material crystallinity and toughness, but also necessitates matching with suitable spinning processes. In view of these various reasons, this invention is proposed. Summary of the Invention

[0006] To address the aforementioned issues, this invention proposes a bio-based, low-carbon, environmentally friendly functional furan polyester fiber and its preparation method. The furan polyester fiber obtained by this invention possesses excellent comprehensive physical properties, including mechanical strength, moisture regain, antistatic properties, low-temperature dyeability, and antibacterial characteristics. Furthermore, since the monomer is derived from biomass, it is a novel, environmentally friendly, high-performance, sustainable bio-based chemical fiber that can be widely used in clothing, carpets, home textiles, and various fabrics.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A method for preparing a bio-based, low-carbon, environmentally friendly functional furan polyester fiber includes the following process steps: a. Preparation of bio-based polyfuran dicarboxylic acid cyclohexanediethanol-ethylene glycol copolyester According to different process formulations, 2,5-furandicarboxylic acid, ethylene glycol, 1,4-cyclohexanediethanol, antioxidant, catalyst and heat stabilizer are added into the polymerization reactor. After replacing the air in the reactor with nitrogen, the temperature is raised and stirred to start the reaction. The reaction proceeds through esterification reaction, pre-condensation reaction and final condensation reaction in sequence. Finally, the material is discharged under pressure with nitrogen and granulated to obtain bio-based furan polyester chips. b. Preparation of bio-based low-carbon environmentally friendly functional furan polyester fibers Bio-based furan polyester chips are crystallized and vacuum dried, then melt-spun to obtain pre-oriented POY yarn. After full texturing, the POY yarn is wound to obtain bio-based low-carbon environmentally friendly functional furan copolyester DTY fiber. Melt spinning is carried out using a single-screw single-component spinning machine, and texturing is performed using a texturing machine.

[0008] Furthermore, in step a, 2,5-furandicarboxylic acid is derived from biomass with a purity ≥99.99%; 1,4-cyclohexanediethanol has a trans proportion ≥70%; the antioxidant is one or more of 1010, SEED, 1098, 412S, and B215; the heat stabilizer is at least one of phosphoric acid, phosphorous acid, hypophosphite, triphenyl phosphate, triphenyl phosphite, ammonium phosphite, and ammonium dihydrogen phosphate; and the catalyst is germanium oxide.

[0009] Furthermore, in step a, the molar ratio of monomers is 2,5-furandicarboxylic acid:diol = 1:1.2~1:1.6; the molar ratio of 1,4-cyclohexanediethanol to ethylene glycol is 40:60~80:20; the amount of catalyst added is 0.01%~0.1% of the mass of 2,5-furandicarboxylic acid; the amount of antioxidant added is 0.05%~0.5% of the mass of 2,5-furandicarboxylic acid; and the amount of heat stabilizer added is 0.005%~0.1% of the mass of 2,5-furandicarboxylic acid.

[0010] Furthermore, in step a, the air inside the polymerization reactor is purged by purging with nitrogen, and this process is repeated 1 to 3 times. The esterification reaction temperature is 180 to 230°C, the esterification pressure is atmospheric pressure, and the reaction time is 2 to 3 hours. The esterification process is completed when the water output reaches the theoretical value. During this stage, the motor stirring speed is maintained at 50 to 150 r / min.

[0011] Furthermore, after the esterification reaction in step a is completed, a pre-condensation reaction is carried out under vacuum. The pre-condensation reaction temperature is 225~245℃, the pressure is <0 MPa, and the reaction time is 0.5~1h. During this stage, the stirring speed is 50~120 r / min. After the pre-condensation reaction is completed, a final condensation reaction is carried out. The final condensation reaction temperature is 255~265℃, the vacuum degree is ≤100 Pa, and the reaction time is 1.5~3h. During this stage, the stirring speed is 20~80 r / min. After the melt reaches the required viscosity, stirring is stopped, nitrogen is introduced to atmospheric pressure, and the mixture is allowed to stand for 3-10 minutes. Nitrogen is then introduced again to discharge the material and granulate it to obtain bio-based furan polyester chips.

[0012] Furthermore, the intrinsic viscosity of the prepared bio-based furan polyester is 0.63-0.80 dL / g.

[0013] Furthermore, in step b, the bio-based furan polyester chips need to be crystallized in a crystallization bed and dried in a drying tower. The crystallization time is 2-4 hours, the crystallization temperature is 130-140℃, and the drying temperature is 140-150℃ for 6-12 hours.

[0014] Furthermore, in step b, the melt spinning temperature is 255~270℃, the screw zone 1-5 temperature is 255~268℃, and the box and vapor phase temperature is 265~270℃; the spinneret orifice diameter is 0.25~0.5mm, and the number of orifices is 36-96; the spinning tunnel cooling method in step b is ring blowing, with an air pressure of 10-20kPa, preferably 14~16kPa; and the spinning speed is 2300~3500m / min.

[0015] Furthermore, in step b, the temperature of the upper heating box in the post-spinning texturing process is 100-130℃, the temperature of the lower heating box is 110-150℃, the network density is 10-30 pieces / m, the draw ratio is 1.5-2.0, and the machine speed is 400-700m / min; the breaking strength of the bio-based low-carbon environmentally friendly functional furan polyester fiber pre-oriented yarn (POY) described in step b is 2.0-2.4cN / dtex, the breaking elongation is 100-120%, and the yarn unevenness is 1.0-1.5%.

[0016] This invention also proposes a bio-based, low-carbon, environmentally friendly functional furan polyester fiber, which is prepared using the method described above.

[0017] This invention pertains to the preparation of bio-based furan copolyester fibers. A bio-based furan copolyester with excellent comprehensive properties is obtained through specific polymerization processes and formulation design using the bio-based monomers 2,5-furandicarboxylic acid, 1,4-cyclohexanediethanol, and ethylene glycol. Combined with spinning and texturing processes, a bio-based low-carbon, environmentally friendly functional furan polyester fiber is prepared. This fiber is free of heavy metals, has a bio-based content >60%, is low-carbon and environmentally friendly, and also possesses low modulus, low heat shrinkage, and other excellent comprehensive physical properties such as antibacterial properties. Attached Figure Description

[0018] Figure 1 This is a photograph of the bio-based furan copolyester chips prepared in Example 1 of the present invention. Figure 2 This is a DSC diagram of the bio-based furan copolyester from Example 1 of the present invention; Figure 3 This is a photograph of the furan-based copolyester POY fiber obtained in Example 1 of the present invention. Figure 4 This is a photograph of the furan-based copolyester DTY fiber obtained in Example 2 of the present invention. Figure 5 This is a physical image of the furan-based copolyester fiber fabric from Embodiment 1 of the present invention. Detailed Implementation

[0019] The present invention will be further described below with reference to specific embodiments.

[0020] General Implementation Examples

[0021] A method for preparing a bio-based, low-carbon, environmentally friendly functional furan polyester fiber includes the following preparation steps: (a) Preparation of bio-based furan copolyester 2,5-furandicarboxylic acid, 1,4-cyclohexanediethanol, ethylene glycol, catalyst, antioxidant, and stabilizer are added to the polymerization reactor. The molar ratio of 2,5-furandicarboxylic acid to the diol is controlled at 1:1.2 to 1:1.6, and the molar fraction of 1,4-cyclohexanediethanol is 40-80% of the total diol, preferably with a trans proportion of >70%. The catalyst is added at 0.01% to 0.1% of the mass of 2,5-furandicarboxylic acid; the antioxidant is added at 0.05% to 0.5% of the mass of 2,5-furandicarboxylic acid; and the heat stabilizer is added at 0.005% to 0.1% of the mass of 2,5-furandicarboxylic acid.

[0022] The reactor was evacuated and nitrogen gas was introduced to replace the air inside, maintaining nitrogen protection. The reactor was heated using a circulating heat transfer medium, while the stirring motor was activated to aid mixing and reaction. First, atmospheric pressure esterification was performed at 180-230℃ for 2-3 hours, completing the esterification reaction when the water output reached the theoretical value and no further output occurred. Next, a pre-condensation reaction was carried out, controlling the reactor temperature at 225-245℃, pressure <0 MPa, and reaction time at 0.5-1 hour. Finally, a final condensation reaction was performed at 255-265℃, vacuum ≤100 Pa, and reaction time at 1.5-3 hours. After the reaction, stirring was stopped, and the material was pressurized with nitrogen and granulated to obtain bio-based furan polyester chips.

[0023] (b) Preparation of bio-based low-carbon environmentally friendly functional furan polyester fiber Bio-based furan polyester chips were crystallized and dried using a vacuum rotary drum oven at a temperature of 130-140℃ for 8-12 hours. The spinning temperature was 255-270℃, the temperature of the screw in zones 1-5 was 255-268℃, and the temperature of the oven and vapor phase was 265-270℃. The spinneret orifice diameter was 0.25-0.5mm, and the number of orifices was 36-96. The temperature of the upper heating box for post-spinning and texturing was 100-130℃, the temperature of the lower heating box was 110-150℃, the network density was 10-30 pieces / m, the draw ratio was 1.5-2.0, and the machine speed was 400-700m / min.

[0024] The specific implementation method is as follows:

[0025] Example 1

[0026] A method for preparing a bio-based, low-carbon, environmentally friendly functional furan polyester fiber includes the following preparation steps: (a) Preparation of bio-based furan copolyester Add 30 kg of 2,5-furandicarboxylic acid, 15.5 kg of 1,4-cyclohexanediethanol (75% trans ratio), 10 kg of ethylene glycol, 30 g of B215, 7.5 g of phosphoric acid, and 10 g of germanium oxide to the polymerization reactor. After adding the materials, seal the reactor and purge the air inside with nitrogen, repeating this process 1-3 times. Start the circulating heat medium to raise the temperature while simultaneously starting the stirrer. The esterification temperature is 180-200℃ at atmospheric pressure, and the time is 1.5-2 hours. The esterification reaction is complete when the water content reaches 95% of the theoretical value and no further water is produced. Next, a pre-condensation reaction is carried out under negative pressure at a temperature of 240-250℃ for 1 hour, with the reactor pressure <0. Finally, a final condensation reaction is carried out at a temperature of 255-265℃ for 2-2.5 hours, with a vacuum degree ≤70 Pa. After the melt reaches the required viscosity, stop stirring, purge with nitrogen to atmospheric pressure, and let it stand for 3 hours. After min, nitrogen gas was passed through again to discharge the material and granulate it to obtain bio-based furan polyester chips.

[0027] (b) Preparation of bio-based low-carbon environmentally friendly functional furan polyester fiber Bio-based furan copolyester was melt-spun and texturized. The chips were first crystallized in a crystallization bed at 130℃ for 2 hours, then dried in a rotary drum oven at 140℃ for 12 hours. The spinning process was as follows: spinning temperature 265℃, oven temperature 268℃, spinning speed 2800 m / min, and ring blowing cooling, successfully producing POY. The texturizing process was as follows: upper heating box temperature 120℃, lower heating box temperature 145℃, network density 20 units / m, draw ratio 1.75, and machine speed 500 m / min. After full texturization, the POY yarn was wound to successfully obtain bio-based furan copolyester DTY fiber with specifications of 75D / 72F.

[0028] (c) Preparation and performance evaluation of bio-based low-carbon and environmentally friendly functional furan polyester fiber fabrics The above DTY fibers were woven, and the related fabrics were dyed and tested for antibacterial properties. The dyeing temperature was 100℃ and the dye type was disperse blue. Antibacterial test was conducted.

[0029] Example 2

[0030] A method for preparing a bio-based, low-carbon, environmentally friendly functional furan polyester fiber includes the following preparation steps: (a) Preparation of bio-based furan copolyester Add 30 kg of 2,5-furandicarboxylic acid, 15.5 kg of 1,4-cyclohexanediethanol (75% trans ratio), 8.15 kg of ethylene glycol, 30 g of antioxidant B215, 7.5 g of phosphoric acid, and 12 g of germanium oxide to the polymerization reactor. After adding the materials, seal the reactor and purge the air inside with nitrogen, repeating this process 1-3 times. Start the circulating heat medium to raise the temperature while simultaneously starting the stirrer. The esterification temperature is 180-200℃ at atmospheric pressure, and the time is 1.5-2 hours. The esterification reaction is complete when the water content reaches 95% of the theoretical value and no further water is produced. Next, a pre-condensation reaction is carried out under negative pressure at a temperature of 240-250℃ for 1 hour, with the reactor pressure <0. Finally, a final condensation reaction is carried out at a temperature of 255-265℃ for 2-2.5 hours, with a vacuum degree ≤70 Pa. After the melt reaches the required viscosity, stop stirring, purge with nitrogen to atmospheric pressure, and let it stand for 3 minutes. Nitrogen gas was passed through the material again for granulation to obtain bio-based furan polyester chips.

[0031] (b) Preparation of bio-based low-carbon environmentally friendly functional furan polyester fiber The spinning process is the same as in Example 1.

[0032] Example 3

[0033] A method for preparing a bio-based, low-carbon, environmentally friendly functional furan polyester fiber includes the following preparation steps: (a) Preparation of bio-based furan copolyester Add 30 kg of 2,5-furandicarboxylic acid, 15.5 kg of 1,4-cyclohexanediethanol (80% trans ratio), 10.0 kg of ethylene glycol, 30 g of antioxidant B215, 7.5 g of phosphoric acid, and 12 g of germanium oxide to the polymerization reactor. After feeding, seal the reactor and purge the air inside with nitrogen. Repeat this process 1-3 times, finally purging with nitrogen as a protective gas at a pressure of 25 kPa. Start the circulating heat medium to raise the temperature while simultaneously starting the agitator. The esterification temperature is 190-200℃, and the time is 1.5-2 hours. The esterification reaction is complete when the water content reaches 95% of the theoretical value and no further output occurs. Next, a negative pressure pre-condensation reaction is carried out at a reaction temperature of 240-250℃ for 1 hour, with the reactor pressure <0. Finally, the final condensation reaction is carried out at a reaction temperature of 255-265℃ for 2-2.5 hours. h, vacuum degree ≤70Pa; after the melt reaches the required viscosity, stop stirring, introduce nitrogen to atmospheric pressure, let stand for 3 min, introduce nitrogen again to discharge and granulate to obtain bio-based furan polyester chips.

[0034] (b) Preparation of bio-based low-carbon environmentally friendly functional furan polyester fiber The spinning process is the same as in Example 1.

[0035] Example 4

[0036] A method for preparing a bio-based, low-carbon, environmentally friendly functional furan polyester fiber includes the following preparation steps: (a) Preparation of bio-based furan copolyester; Polyester preparation is the same as in Example 1. (b) Preparation of bio-based low-carbon environmentally friendly functional furan polyester fiber Bio-based furan copolyester was melt-spun and texturized. After crystallization, the shavings were dried at 140℃ for 12 hours. The spinning process was as follows: spinning temperature 265℃, chamber temperature 268℃, spinning speed 2800m / min, and ring blowing cooling, successfully producing POY. The texturizing process was as follows: upper heating chamber temperature 120℃, lower heating chamber temperature 145℃, network density 20 units / m, draw ratio 1.85, and machine speed 400m / min. After full texturization, the POY yarn was wound to successfully obtain bio-based furan copolyester DTY fiber.

[0037] Example 5

[0038] A method for preparing a bio-based, low-carbon, environmentally friendly functional furan polyester fiber includes the following preparation steps: (a) Preparation of bio-based furan copolyester The polyester preparation is the same as in Example 1; (b) Preparation of bio-based low-carbon environmentally friendly functional furan polyester fiber Bio-based furan copolyester was melt-spun and texturized. After crystallization, the slicing was dried at 140℃ for 12 hours. The spinning process was as follows: spinning temperature 265℃, box temperature 268℃, spinning speed 3000m / min, and ring blowing cooling, successfully producing POY. The texturizing process was as follows: upper heating box temperature 120℃, lower heating box temperature 145℃, network density 20 units / m, draw ratio 1.75, and machine speed 400m / min. After full texturization, the POY yarn was wound to successfully obtain bio-based furan copolyester DTY fiber.

[0039] Example 6

[0040] A method for preparing a bio-based, low-carbon, environmentally friendly functional furan polyester fiber includes the following preparation steps: (a) Preparation of bio-based furan copolyester The polyester preparation is the same as in Example 1; (b) Preparation of bio-based low-carbon environmentally friendly functional furan polyester fiber Bio-based furan copolyester was melt-spun and texturized. After crystallization, the slicing was dried at 140℃ for 12 hours. The spinning process was as follows: spinning temperature 265-270℃, box temperature 268℃, spinning speed 3000m / min, and ring blowing cooling, successfully producing POY. The texturizing process was as follows: upper heating box temperature 120℃, lower heating box temperature 145℃, network density 20 pieces / m, draw ratio 1.85, and machine speed 400m / min. After full texturization, the POY yarn was wound to successfully obtain bio-based furan copolyester DTY fiber.

[0041] Comparative Example 1 A method for preparing a bio-based, low-carbon, environmentally friendly functional furan polyester fiber includes the following preparation steps: (a) Preparation of bio-based furan polyester 30 kg of 2,5-furandicarboxylic acid, 1167 g of ethylene glycol, 30 g of antioxidant B215, 7.5 g of phosphoric acid, and 12 g of germanium oxide were added to a polymerization reactor. After the materials were added, the reactor was sealed, and the air inside was replaced by nitrogen gas. This process was repeated 1-3 times. The circulating heat medium was started to raise the temperature, and stirring was started simultaneously. The esterification temperature was 180-195℃ at atmospheric pressure, and the time was 1.5-2 h. The esterification reaction was completed when the water content reached 95% of the theoretical value and no more water was produced. Then, a pre-condensation reaction was carried out under negative pressure at a reaction temperature of 235-240℃ for 1 h, with the pressure inside the reactor <0. Finally, the final condensation reaction was carried out at a reaction temperature of 240-250℃ for 2-2.5 h, with a vacuum degree ≤70 Pa. After the melt reached the required viscosity, stirring was stopped, nitrogen gas was introduced to atmospheric pressure, and the mixture was allowed to stand for 3 min. Nitrogen gas was introduced again, and the mixture was discharged and granulated to obtain bio-based furan polyester chips.

[0042] (b) Preparation of bio-based low-carbon environmentally friendly functional furan polyester fiber Bio-based furan polyester (PEF) was melt-spun and texturized. After crystallization, the shavings were dried at 140℃ for 12 hours. The spinning process was as follows: spinning temperature 265℃, chamber temperature 268℃, spinning speed 2800 m / min, and ring blowing cooling, successfully producing POY. The texturizing process was as follows: upper heating chamber temperature 120℃, lower heating chamber temperature 145℃, network density 20 units / m, draw ratio 1.75, and machine speed 400 m / min. After full texturization, the POY yarn was wound to successfully obtain bio-based furan copolyester (DTY) fiber.

[0043] Comparative Example 2 A method for preparing a bio-based, low-carbon, environmentally friendly functional furan polyester fiber includes the following preparation steps: (a) Preparation of bio-based furan polyester Add 30 kg of 2,5-furandicarboxylic acid, 35.5 kg of 1,4-cyclohexanediethanol (75% trans ratio), 30 g of antioxidant B215, 7.5 g of phosphoric acid, and 12 g of germanium oxide to a polymerization reactor. After feeding, seal the reactor and purge the air inside with nitrogen, repeating this process 1-3 times. Start the circulating heat medium to raise the temperature while simultaneously stirring. Esterification is carried out at atmospheric pressure at 180-220℃ for 2-3 hours. The esterification reaction is complete when the water output reaches the theoretical value and no more water is produced. Next, a pre-condensation reaction is carried out under negative pressure at 235-240℃ for 1 hour, with the reactor pressure <0. Finally, final condensation is carried out at 275-280℃ for 2-2.5 hours, with a vacuum degree ≤70 Pa. After the melt reaches the required viscosity, stop stirring, purge with nitrogen to atmospheric pressure, let stand for 3 minutes, purge with nitrogen again, and then granulate to obtain bio-based furan polyester chips.

[0044] Comparative Example 3 A method for preparing a bio-based, low-carbon, environmentally friendly functional furan polyester fiber includes the following preparation steps: (a) Preparation of bio-based furan polyester The polyester preparation is the same as in Example 1; (b) Preparation of bio-based low-carbon environmentally friendly functional furan polyester fiber Bio-based furan copolyester was melt-spun and texturized. After crystallization, the slicing was dried at 140℃ for 12 hours. The spinning process was as follows: spinning temperature 265-270℃, box temperature 268℃, spinning speed 3000m / min, and ring blowing cooling, successfully producing POY. The texturizing process was as follows: upper heating box temperature 150℃, lower heating box temperature 175℃, network density 20 units / m, draw ratio 1.70, and machine speed 500m / min. After full texturization, the POY yarn was wound to successfully obtain bio-based furan copolyester DTY fiber.

[0045] The above examples and comparative examples were subjected to performance tests. The intrinsic viscosity was determined according to GB / T 14190-2017. The melting and crystallization behavior was determined by differential scanning calorimetry (DSC) under the following conditions: nitrogen atmosphere, gas flow rate 20 ml / min, sample temperature was increased from 30℃ to 280℃ at a rate of 10℃ / min, held for 3 min, then cooled to 30℃ at a rate of 10℃ / min, held for 3 min, and then heated to 280℃ again at a rate of 10℃ / min. The boiling water shrinkage rate was determined according to GB / T 6505-2017. The mechanical properties were determined according to GB / T 14344-2022. The antibacterial properties were determined according to GB / T 20944.3-2008 using the oscillation method. The specific test data are shown in the table below.

[0046]

[0047] According to the table above, comparing Examples 1-3 with Comparative Examples 1 and 2, it is evident that in Comparative Example 1, polyethylene furanate dicarboxylate (PEF) showed no melting peak during DSC testing, indicating an amorphous state. In Comparative Example 2, polycyclohexanediethanol (PCF) exhibited a clear melting peak, but its melting point was high, and it was difficult to obtain high molecular weights during polymerization, making spinning impossible. In contrast, the furan copolyester prepared from 1,4-cyclohexanediethanol possessed a suitable melting point and crystallization temperature, classifying it as a crystalline polymer. Furthermore, its fiber's heat shrinkage rate (boiling water shrinkage rate) was significantly reduced, meeting the requirements for normal subsequent weaving and dyeing processes. Figures 1-3 The images shown are: sliced ​​physical images, DSC data images, and physical images of POY and DTY fibers prepared in Example 1. In Examples 1-3, furan copolyesters with different contents and different trans ratios of 1,4-cyclohexanediethanol (CHDM) were prepared. From the melting point of the copolyester and the fiber data, it can be seen that the CHDM-modified furan polyesters within the scope of this invention can be well spun and processed. The fibers exhibit good mechanical properties, boiling water shrinkage, and antibacterial properties. Due to the high compatibility between the six-membered ring structure of CHDM and the 2,5-furandicarboxylic acid molecule, its macromolecular chain arrangement is more regular, and the orientation and crystallization trend during the spinning process are more obvious.

[0048] In Examples 4-6, the furan copolyester spinning process in Example 1 was adjusted. Compared with Comparative Example 3, it can be clearly seen that the hot box temperature and stretching process have a great influence on the mechanical properties and heat shrinkage rate of furan-based copolyester fibers. Therefore, the combination of polymerization, spinning, texturing and other processes is necessary to develop bio-based furan copolyesters that meet application requirements. In summary, high-performance bio-based low-carbon environmentally friendly functional furan polyester fibers can be prepared in all the above examples.

[0049] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a bio-based, low-carbon, environmentally friendly functional furan polyester fiber, characterized in that, Includes the following steps: a. Preparation of bio-based polyfuran dicarboxylic acid cyclohexanediethanol-ethylene glycol copolyester 2,5-furandicarboxylic acid, ethylene glycol, 1,4-cyclohexanediethanol, antioxidant, catalyst, and heat stabilizer are added to a polymerization reactor. After purging the reactor with nitrogen, the temperature is increased and the mixture is stirred to initiate the reaction. The reaction proceeds sequentially through esterification, pre-condensation, and final condensation. Finally, the mixture is pressurized with nitrogen and discharged for granulation to obtain bio-based furan polyester chips. The 1,4-cyclohexanediethanol has a trans-form ratio of ≥70%. The catalyst is germanium oxide. b. Preparation of bio-based low-carbon environmentally friendly functional furan polyester fibers Bio-based furan polyester chips are crystallized and vacuum dried, and then melt-spun to obtain pre-oriented POY yarn. After the POY yarn is fully textured, it is wound to obtain bio-based low-carbon environmentally friendly functional furan copolyester DTY fiber.

2. The method for preparing a bio-based low-carbon environmentally friendly functional furan polyester fiber according to claim 1, characterized in that, In step a, 2,5-furandicarboxylic acid is derived from biomass with a purity ≥99.99%; the antioxidant is one or more of 1010, SEED, 1098, 412S, and B215; and the heat stabilizer is at least one of phosphoric acid, phosphorous acid, hypophosphite, triphenyl phosphate, triphenyl phosphite, ammonium phosphite, and ammonium dihydrogen phosphate.

3. The method for preparing a bio-based low-carbon environmentally friendly functional furan polyester fiber according to claim 1, characterized in that, In step a, the molar ratio of monomers is 2,5-furandicarboxylic acid:diol = 1:1.2~1:1.6; the molar ratio of 1,4-cyclohexanediethanol to ethylene glycol is 40:60~80:20; the amount of catalyst added is 0.01%~0.1% of the mass of 2,5-furandicarboxylic acid; the amount of antioxidant added is 0.05%~0.5% of the mass of 2,5-furandicarboxylic acid; and the amount of heat stabilizer added is 0.005%~0.1% of the mass of 2,5-furandicarboxylic acid.

4. The method for preparing a bio-based low-carbon environmentally friendly functional furan polyester fiber according to claim 1, characterized in that, In step a, the air inside the polymerization reactor is purged by purging with nitrogen, and this process is repeated 1 to 3 times. The esterification reaction temperature is 180 to 230°C, the esterification pressure is atmospheric pressure, and the reaction time is 2 to 3 hours. The esterification process is completed when the water output reaches the theoretical value. During this stage, the motor stirring speed is maintained at 50 to 150 r / min.

5. The method for preparing a bio-based low-carbon environmentally friendly functional furan polyester fiber according to claim 1, characterized in that, After the esterification reaction in step a is completed, a pre-condensation reaction is carried out under vacuum. The pre-condensation reaction temperature is 225~245℃, the pressure is <0 MPa, and the reaction time is 0.5~1h. During this stage, the stirring speed is 50~120 r / min. After the pre-condensation reaction is completed, a final condensation reaction is carried out. The final condensation reaction temperature is 255~265℃, the vacuum degree is ≤100 Pa, and the reaction time is 1.5~3h. During this stage, the stirring speed is 20~80 r / min. After the melt reaches the required viscosity, stirring is stopped, nitrogen is introduced to atmospheric pressure, and the mixture is allowed to stand for 3-10 minutes. Nitrogen is introduced again to discharge the material and granulate it to obtain bio-based furan polyester chips.

6. The method for preparing a bio-based low-carbon environmentally friendly functional furan polyester fiber according to claim 1, characterized in that, The intrinsic viscosity of the prepared bio-based furan polyester is 0.63-0.80 dL / g.

7. The method for preparing a bio-based low-carbon environmentally friendly functional furan polyester fiber according to claim 1, characterized in that, In step b, the bio-based furan polyester chips need to be crystallized in a crystallization bed and dried in a drying tower. The crystallization time is 2-4 hours and the crystallization temperature is 130-140℃. The drying temperature is 140-150℃ and the drying time is 6-12 hours.

8. The method for preparing a bio-based low-carbon environmentally friendly functional furan polyester fiber according to claim 1, characterized in that, In step b, the melt spinning temperature is 255~270℃, the screw zone 1-5 temperature is 255~268℃, and the box and vapor phase temperature is 265~270℃; the spinneret orifice diameter is 0.25~0.5mm, and the number of orifices is 36-96; the spinning tunnel cooling method in step b is ring blowing, with an air pressure of 10-20kPa, preferably 14~16kPa; and the spinning speed is 2300~3500m / min.

9. The method for preparing a bio-based low-carbon environmentally friendly functional furan polyester fiber according to claim 1, characterized in that, In step b, the temperature of the upper heating box in the post-spinning and texturing process is 100-130℃, the temperature of the lower heating box is 110-150℃, the network density is 10-30 pieces / m, the draw ratio is 1.5-2.0, and the machine speed is 400-700m / min. The breaking strength of the bio-based low-carbon environmentally friendly functional furan polyester fiber pre-oriented yarn (POY) described in step b is 2.0-2.4cN / dtex, the breaking elongation is 100-120%, and the yarn unevenness is 1.0-1.5%.

10. A bio-based, low-carbon, environmentally friendly functional furan polyester fiber, characterized in that, It is prepared by the preparation method described in any one of claims 1-9.

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