Colored polyethylene 2,5-furandicarboxylate glycol ester fibers and methods for making the same

Abstract

The application discloses a colored poly(ethylene-2,5-furandicarboxylate) fiber, which comprises 2,5-furandicarboxylic acid, ethylene glycol, a catalyst, a crosslinking agent and a pigment, and the pigment is a bio-based dye or a colorant. The application further discloses a preparation method of the colored poly(ethylene-2,5-furandicarboxylate) fiber. Bio-based dyes treated by ultrasonic waves are used to efficiently dye poly(ethylene-2,5-furandicarboxylate) fibers obtained by polymerization and spinning of poly(2,5-furandicarboxylic acid) and ethylene glycol. In the dyeing process of the poly(ethylene-2,5-furandicarboxylate) fiber, dyeing carriers or dyeing auxiliaries are added, so that the affinity between the bio-based dyes and the fiber can be improved, the dyeing performance is further improved, and a pre-mordanting treatment is performed through metal ions, so that the dyes and the metal ions form a coordination, the energy level interval of an electron transition of a dye color system is changed, and then the color and the dyeing fastness of the dyes are effectively changed.

Description

Technical Field

[0001] This invention relates to a colored polyethylene 2,5-furandicarboxylate fiber and its preparation method, belonging to the field of dyeing technology for synthetic fiber materials. Background Technology

[0002] With the rapid development of global industrialization, human demand for petrochemical resources is constantly increasing. Therefore, the depletion of petroleum resources and its environmental impact have become unavoidable issues. In recent years, renewable resources and their application in polymers have gradually become a focus of attention. Utilizing plant resources to prepare monomers required for polymer synthesis has proven to be a feasible approach, and the development and application of polymer materials based on renewable resources have progressed rapidly. Poly(2,5-furandicarboxylate) fiber belongs to a new type of biodegradable bio-based fiber. Its main chain is composed of 2,5-furandicarboxylic acid and ethylene glycol units. 2,5-furandicarboxylic acid is a diacid derived from fructose and galactose in natural plants, which is easily obtained in nature and is mainly extracted from biomass raw materials such as corn and non-agricultural crops, straw, and sawdust. Ethylene glycol G is also synthesized from renewable raw materials, making poly(2,5-furandicarboxylate) fiber a 100% bio-based and fully recyclable material. The preparation and synthesis of new polymer polyester materials using 2,5-furandicarboxylic acid as a raw material realizes the leap from petroleum resources to renewable biomass resources, alleviates the polyester industry's dependence on petroleum resources, expands the development and utilization of green biomass resources, and is also an innovation for the further development of biopolymer materials.

[0003] However, as a bio-based alternative to petroleum-based fibers, compared to polyethylene 2,5-furandicarboxylate, the 2,5-furandicarboxylic acid unit structure is asymmetrical, making chain segments difficult to flip. Simultaneously, the furan rings possess a permanent dipole moment due to the non-coincidence of positive and negative charge centers, generating electrostatic forces that increase the interchain interactions of polyethylene 2,5-furandicarboxylate. This makes it difficult for the polymer chains to move, resulting in significant intermolecular steric hindrance. Polyethylene 2,5-furandicarboxylate also has a high glass transition temperature, typically around 88°C, and the fibers are light brown. Its unique aggregated structure and appearance make it difficult to dye, and research on its dyeing and related patents are rarely reported. Therefore, it is necessary to propose a colored polyethylene 2,5-furandicarboxylate fiber and its preparation method to solve the dyeing problem of the new green PEF fiber and its products caused by structural and performance reasons, so as to improve the chemical properties and applicability of colored polyethylene 2,5-furandicarboxylate fiber, thereby expanding the production of related new green environmentally friendly and biodegradable fibers. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned problems and provide a colored polyethylene 2,5-furandicarboxylate fiber and its preparation method.

[0005] The technical solution of the present invention is: a colored polyethylene 2,5-furandicarboxylate fiber, characterized in that, by weight ratio, the raw materials for preparing the fiber contain: 25-90 parts of 2,5-furandicarboxylic acid, 30-260 parts of ethylene glycol, 7-12 parts of catalyst, 7-12 parts of crosslinking agent, and 12-20 parts of pigment.

[0006] Furthermore, in the above-mentioned colored polyethylene 2,5-furandicarboxylate fiber, the molar ratio of 2,5-furandicarboxylic acid to ethylene glycol is: 2,5-furandicarboxylic acid: ethylene glycol = 1: (1.2~2.8).

[0007] Furthermore, in the above-mentioned colored polyethylene 2,5-furandicarboxylate fiber, the catalyst is one or more of tetrabutyl titanate, p-toluenesulfonic acid, cation exchange resin, and boron trifluoride.

[0008] Furthermore, in the above-mentioned colored polyethylene 2,5-furandicarboxylate fiber, the crosslinking agent is one or more of divinylbenzene, diisocyanate, and N,N-methylenebisacrylamide.

[0009] Furthermore, in the above-mentioned colored polyethylene 2,5-furandicarboxylate fiber, the pigment is a bio-based dye or colorant.

[0010] Furthermore, in the aforementioned colored polyethylene 2,5-furandicarboxylate fiber, the bio-based dye is a natural dye having cationic groups or having anthraquinone, naphthoquinone, or other structures similar to disperse dyes, with a small molecular weight and hydrophobic, relatively stable structure; preferably, the bio-based dye is one or more of indigo, madder, safflower, shellac, onion purple, turmeric, lithospermum, and lutein.

[0011] This invention also provides a method for preparing colored polyethylene 2,5-furandicarboxylate fibers, comprising the following steps:

[0012] Step (1): Mix 2,5-furandicarboxylic acid with ethylene glycol and carry out esterification reaction to generate 2,5-furandicarboxylic acid ethylene glycol ester and water; after removing water, add catalyst and crosslinking agent to 2,5-furandicarboxylic acid ethylene glycol ester and carry out polycondensation reaction under vacuum to synthesize poly2,5-furandicarboxylic acid ethylene glycol ester, and obtain poly2,5-furandicarboxylic acid ethylene glycol ester fiber by melt spinning and expansion treatment;

[0013] Step (2): The polyethylene 2,5-furandicarboxylate fiber obtained in step (1) is subjected to dyeing pretreatment. A treatment solution containing 2 g / L detergent POEA and 2 g / L sodium carbonate is added to the polyethylene 2,5-furandicarboxylate fiber. The fiber is soaked for 10 to 30 minutes at a temperature of 30 to 50°C. After washing with water, the fiber surface is dried to remove the oil, and the dyed polyethylene 2,5-furandicarboxylate fiber is obtained.

[0014] Step (3): The pigment is pretreated by ultrasound with an ultrasound power of 500-700W, an ultrasound frequency of 40-60HZ, an ultrasound treatment temperature of 40-60℃, and an ultrasound treatment time of 20-40min. The pigment is then dispersed and dissolved in deionized water at a temperature of 40-60℃. The pigment is filtered to remove plant residues. After adjusting the pH value with an acetic acid / sodium acetate buffer solution, it is used for dyeing polyethylene 2,5-furandicarboxylate fibers.

[0015] Step (4): The pretreated polyethylene 2,5-furandicarboxylate fiber is dyed under acidic conditions using the dye pretreated pigment from step (3). The dyeing method is one of the following: high temperature and high pressure dyeing method, environmentally friendly metal mordant dyeing method, ultrasonic treatment dyeing method, and ultrasonic treatment carrier dyeing method. The dyeing concentration is 3.5 owf%, and the liquor ratio is 1:20. The dyeing process involves heating the fiber to 80℃ at a rate of 1.5℃ / min, then heating it to 120℃ at a rate of 0.8℃ / min, holding it at that temperature for 40-60 min, and then cooling it to 50℃ at a rate of 3.0℃ / min. The polyethylene 2,5-furandicarboxylate fiber is then removed, washed, and dried to obtain colored polyethylene 2,5-furandicarboxylate fiber.

[0016] Furthermore, in the above-mentioned method for preparing colored polyethylene 2,5-furandicarboxylate fiber, in step S4, the environmentally friendly metal mordant dyeing method includes an environmentally friendly metal mordant, which is one or more of the following: zinc salt mordant, iron salt mordant, aluminum salt mordant, and titanium salt mordant that do not contain heavy metals.

[0017] Furthermore, in the above-mentioned method for preparing colored polyethylene 2,5-furandicarboxylate fiber, in step S4, the ultrasonic treatment-assisted dyeing method includes a dyeing auxiliary agent, which is one or more of sodium lignosulfonate, dispersant NNO, dispersant MF, and dispersant CNF, to improve the binding force between the dye and the fiber.

[0018] Furthermore, in the above-mentioned method for preparing colored polyethylene 2,5-furandicarboxylate fiber, in step S4, the ultrasonic treatment carrier-assisted dyeing method includes a dyeing carrier, wherein the dyeing carrier is one or more of the natural dyeing auxiliaries T258, T2 and T286, which improves the binding force between the dye and the fiber.

[0019] Furthermore, in the above-mentioned method for preparing colored polyethylene 2,5-furandicarboxylate fiber, in step S4, the high-temperature and high-pressure dyeing method is to dye without adding dyeing auxiliaries and through a sealed dyeing tank, wherein the pressure inside the sealed dyeing tank is greater than 101.325 kPa and the temperature of the dyeing solution is 120-130℃.

[0020] Thus, by employing the technical solution of this invention, ultrasonic pretreatment of pigments and dyes reduces the particle size of the dyes, effectively improving the dispersion uniformity and solubility in the dye liquor; it can also effectively remove oligomers generated on the surface of polyethylene 2,5-furandicarboxylate fibers and cause volume changes in their internal structure, generating more cavitation and microbubbles, which helps to promote dyeing and improve dyeing efficiency.

[0021] Compared with the prior art, the technical solution of this invention uses metal ions for pre-mordant treatment, which enables the dye to form a complex with the metal ions, thereby changing the energy level interval of the electronic transition in the dye color development system, and thus effectively changing the color and color fastness of the dye. Adding a dyeing carrier or dyeing auxiliary agent during the dyeing process of polyethylene 2,5-furandicarboxylate fiber can improve the affinity between bio-based dyes and fibers, and further improve the dyeing performance. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is further described below with reference to specific examples. However, it should not be construed that the scope of protection of the above-mentioned subject matter of this invention is limited to the following embodiments. All raw materials used are commercially available or prepared using methods known in the industry.

[0023] Example 1

[0024] Step (1) Mix 25 parts of 2,5-furandicarboxylic acid with 30 parts of ethylene glycol and carry out esterification reaction to generate ethylene glycol 2,5-furandicarboxylic acid and water; after removing water, add 7 parts of tetrabutyl titanate and 8 parts of diisocyanate to ethylene glycol 2,5-furandicarboxylic acid and carry out polycondensation reaction under vacuum to synthesize polyethylene 2,5-furandicarboxylic acid, and obtain polyethylene 2,5-furandicarboxylic acid fiber by melt spinning and expansion treatment.

[0025] Step (2) The polyethylene 2,5-furandicarboxylate fiber obtained in step (1) is subjected to dyeing pretreatment. A treatment solution containing 2 g / L detergent POEA and 2 g / L sodium carbonate is added to the polyethylene 2,5-furandicarboxylate fiber. The fiber is soaked at 40°C for 20 min. After washing with water, the fiber is dried to remove the oil from the fiber surface, and the dyed polyethylene 2,5-furandicarboxylate fiber is obtained.

[0026] Step (3) The indigo dye is pretreated by ultrasound with an ultrasound power of 500-700W, an ultrasound frequency of 50HZ, a temperature of 50℃, and an ultrasound treatment time of 30min. The dye is then dispersed and dissolved in deionized water at 50℃. The dye is filtered to remove plant residues. After adjusting the pH value with an acetic acid / sodium acetate buffer solution, it is used for dyeing polyethylene 2,5-furandicarboxylate fibers.

[0027] Step (4) involves dyeing the polyethylene 2,5-furandicarboxylate fibers pre-degreased by ultrasonication with indigo dye under acidic conditions, as described in step (3). The dyeing concentration is 3.5 (owf%), the liquor ratio is 1:20, the temperature is increased to 80℃ at a rate of 1.5℃ / min, then increased to 120℃ at a rate of 0.8℃ / min, held for 50 min, and then cooled to 50℃ at a rate of 3.0℃ / min. The polyethylene 2,5-furandicarboxylate fibers are then removed, washed, and dried to obtain blue polyethylene 2,5-furandicarboxylate fibers.

[0028] Example 2

[0029] Step (1) Mix 25 parts of 2,5-furandicarboxylic acid with 30 parts of ethylene glycol and carry out esterification reaction to generate ethylene glycol 2,5-furandicarboxylic acid and water; after removing the water, add 7 parts of boron trifluoride and 8 parts of divinylbenzene to ethylene glycol 2,5-furandicarboxylic acid and carry out polycondensation reaction under vacuum to synthesize polyethylene 2,5-furandicarboxylic acid, and obtain polyethylene 2,5-furandicarboxylic acid fiber by melt spinning and expansion treatment.

[0030] Step (2) The polyethylene 2,5-furandicarboxylate fiber obtained in step (1) is subjected to dyeing pretreatment. A treatment solution containing 2 g / L detergent POEA and 2 g / L sodium carbonate is added to the polyethylene 2,5-furandicarboxylate fiber. The fiber is soaked at 40°C for 20 min. After washing with water, the fiber is dried to remove the oil from the fiber surface, and the dyed polyethylene 2,5-furandicarboxylate fiber is obtained.

[0031] Step (3) The lac dye is pretreated by ultrasound with an ultrasound power of 500W, an ultrasound frequency of 50HZ, an ultrasound treatment temperature of 50℃, and an ultrasound treatment time of 30min. The dye is then dispersed and dissolved in deionized water at 50℃. The dye is filtered to remove plant residues. After adjusting the pH value with an acetic acid / sodium acetate buffer solution, it is used for dyeing polyethylene 2,5-furandicarboxylate fibers.

[0032] Step (4) involves dyeing the polyethylene 2,5-furandicarboxylate fibers pre-degreased by ultrasonication with lac dye under acidic conditions, using the dye concentration of 4.0 (owf%) and a liquor ratio of 1:15. The temperature is increased to 80°C at a rate of 1.5°C / min, then increased to 125°C at a rate of 1.0°C / min, held for 60 min, and then cooled to 50°C at a rate of 3.0°C / min. The polyethylene 2,5-furandicarboxylate fibers are then removed, washed, and dried to obtain orange-red polyethylene 2,5-furandicarboxylate fibers.

[0033] Example 3

[0034] Step (1) Mix 25 parts of 2,5-furandicarboxylic acid with 30 parts of ethylene glycol and carry out esterification reaction to generate ethylene glycol 2,5-furandicarboxylic acid and water; after removing water, add 7 parts of tetrabutyl titanate and 8 parts of diisocyanate to ethylene glycol 2,5-furandicarboxylic acid and carry out polycondensation reaction under vacuum to synthesize polyethylene 2,5-furandicarboxylic acid, and obtain polyethylene 2,5-furandicarboxylic acid fiber by melt spinning and expansion treatment.

[0035] Step (2) The polyethylene 2,5-furandicarboxylate fiber obtained in step (1) is subjected to dyeing pretreatment. A treatment solution containing 2 g / L detergent POEA and 2 g / L sodium carbonate is added to the polyethylene 2,5-furandicarboxylate fiber. The fiber is soaked at 40°C for 20 min. After washing with water, the fiber is dried to remove the oil from the fiber surface, and the dyed polyethylene 2,5-furandicarboxylate fiber is obtained.

[0036] Step (3) The madder dye is subjected to ultrasonic pretreatment with an ultrasonic power of 500W, an ultrasonic frequency of 50HZ, an ultrasonic treatment temperature of 50℃, and an ultrasonic treatment time of 30min. The dye is then dispersed and dissolved in deionized water at 50℃. The dye is filtered to remove plant residues. After adjusting the pH value with an acetic acid / sodium acetate buffer solution, it is used for dyeing polyethylene 2,5-furandicarboxylate fibers.

[0037] Step (4) involves dyeing the polyethylene 2,5-furandicarboxylate fibers pre-degreased by ultrasonication with madder dye under acidic conditions, as described in step (3). The dyeing concentration is 4.0 (owf%), the liquor ratio is 1:20, the temperature is increased to 80℃ at a rate of 1.5℃ / min, then increased to 130℃ at a rate of 1.0℃ / min, held for 50 min, and then cooled to 50℃ at a rate of 3.0℃ / min. The polyethylene 2,5-furandicarboxylate fibers are then removed, washed, and dried to obtain dark red polyethylene 2,5-furandicarboxylate fibers.

[0038] Example 4

[0039] Step (1) Mix 25 parts of 2,5-furandicarboxylic acid with 30 parts of ethylene glycol and carry out esterification reaction to generate ethylene glycol 2,5-furandicarboxylic acid and water; after removing water, add 7 parts of tetrabutyl titanate and 8 parts of diisocyanate to ethylene glycol 2,5-furandicarboxylic acid and carry out polycondensation reaction under vacuum to synthesize polyethylene 2,5-furandicarboxylic acid, and obtain polyethylene 2,5-furandicarboxylic acid fiber by melt spinning and expansion treatment.

[0040] Step (2) involves pre-dyeing the polyethylene 2,5-furandicarboxylate fibers obtained in step (1). The fibers are immersed in a treatment solution containing 2 g / L POEA detergent and 2 g / L sodium carbonate at 40°C for 20 minutes. After washing with water, the fibers are dried to remove the oil from their surface. The de-oiled polyethylene 2,5-furandicarboxylate fibers are then subjected to iron salt pre-mordant treatment at a concentration of 0.60 x 10⁻⁶. -3 Poly(2,5-furandicarboxylate) fibers were obtained after dyeing pretreatment at a temperature of 60℃ and a working temperature of mol / g for 30 min.

[0041] Step (3) Pre-treat lutein with ultrasound. The ultrasound power is 500W, the ultrasound frequency is 50HZ, the temperature required for ultrasound treatment is 50℃, and the ultrasound treatment time is 30min. Then, the pigment is dispersed and dissolved in deionized water at 50℃. The pigment is filtered to remove plant residues. After adjusting the pH value to 5.0 with acetic acid / sodium acetate buffer solution, it is used for dyeing polyethylene 2,5-furandicarboxylate fibers.

[0042] Step (4) involves dyeing the polyethylene 2,5-furandicarboxylate fibers pre-degreased by ultrasonication under acidic conditions using lutein as described in step (3). The dyeing concentration is 4.0 (owf%), the liquor ratio is 1:15, the temperature is increased to 70℃ at a rate of 1.5℃ / min, then increased to 100℃ at a rate of 0.8℃ / min, held for 60 min, and then cooled to 50℃ at a rate of 2.0℃ / min. The polyethylene 2,5-furandicarboxylate fibers are then removed, washed, and dried to obtain yellow polyethylene 2,5-furandicarboxylate fibers.

[0043] Example 5

[0044] Step (1) Mix 25 parts of 2,5-furandicarboxylic acid with 30 parts of ethylene glycol and carry out esterification reaction to generate ethylene glycol 2,5-furandicarboxylic acid and water; after removing water, add 7 parts of tetrabutyl titanate and 8 parts of diisocyanate to ethylene glycol 2,5-furandicarboxylic acid and carry out polycondensation reaction under vacuum to synthesize polyethylene 2,5-furandicarboxylic acid, and obtain polyethylene 2,5-furandicarboxylic acid fiber by melt spinning and expansion treatment.

[0045] Step (2) The polyethylene 2,5-furandicarboxylate fiber obtained in step (1) is subjected to dyeing pretreatment. A treatment solution containing 2 g / L detergent POEA and 2 g / L sodium carbonate is added to the polyethylene 2,5-furandicarboxylate fiber. The fiber is soaked at 40°C for 20 min. After washing with water, the fiber is dried to remove the oil from the fiber surface, and the dyed polyethylene 2,5-furandicarboxylate fiber is obtained.

[0046] Step (3) The curcumin dye is pretreated with ultrasound. The ultrasound power is 500W, the ultrasound frequency is 50HZ, the temperature required for ultrasound treatment is 50℃, and the ultrasound treatment time is 30min. Then, the pigment is dispersed and dissolved in deionized water at 50℃. The pigment is filtered to remove plant residues. After adjusting the pH value by adding acetic acid / sodium acetate buffer solution, it is used for dyeing polyethylene 2,5-furandicarboxylate fibers.

[0047] Step (4) involves dyeing the polyethylene 2,5-furandicarboxylate fibers pre-degreased by ultrasonication with curcumin dye under acidic conditions, as described in step (3). The dye pH is between 5.0 and 6.0, the dyeing concentration is 5.0 (owf%), the liquor ratio is 1:15, the temperature is increased to 70°C at a rate of 1.5°C / min, then increased to 100°C at a rate of 0.8°C / min, held for 60 min, and then cooled to 50°C at a rate of 2.0°C / min. The polyethylene 2,5-furandicarboxylate fibers are then removed, washed, and dried to obtain orange-yellow polyethylene 2,5-furandicarboxylate fibers.

[0048] Example 6

[0049] Step (1) Mix 25 parts of 2,5-furandicarboxylic acid with 30 parts of ethylene glycol and carry out esterification reaction to generate ethylene glycol 2,5-furandicarboxylic acid and water; after removing water, add 7 parts of cation exchange resin and 8 parts of diisocyanate to ethylene glycol 2,5-furandicarboxylic acid and carry out polycondensation reaction under vacuum to synthesize polyethylene 2,5-furandicarboxylic acid, and obtain polyethylene 2,5-furandicarboxylic acid fiber by melt spinning and expansion treatment.

[0050] Step (2) The polyethylene 2,5-furandicarboxylate fiber obtained in step (1) is subjected to dyeing pretreatment. A treatment solution containing 2 g / L detergent POEA and 2 g / L sodium carbonate is added to the polyethylene 2,5-furandicarboxylate fiber. The fiber is soaked at 40°C for 20 min. After washing with water, the fiber is dried to remove the oil from the fiber surface, and the dyed polyethylene 2,5-furandicarboxylate fiber is obtained.

[0051] Step (3) The onion purple dye is pretreated by ultrasound with an ultrasound power of 500W, an ultrasound frequency of 50HZ, an ultrasound treatment temperature of 50℃, and an ultrasound treatment time of 30min. The dye is then dispersed and dissolved in deionized water at 50℃. The dye is filtered to remove plant residues. The filtered onion purple dye solution is then mixed with dyeing aid T2 (concentration 20g / L) and stirred evenly before being used for dyeing polyethylene 2,5-furandicarboxylate fibers.

[0052] Step (4) involves dyeing the polyethylene 2,5-furandicarboxylate fibers pre-degreased by ultrasonication with onion purple dye under acidic conditions, as described in step (3). The dye pH is between 5.0 and 6.0, the dyeing concentration is 4.0 (owf%), the liquor ratio is 1:15, the temperature is increased to 70℃ at a rate of 1.5℃ / min, then increased to 100℃ at a rate of 0.8℃ / min, held for 70 min, and then cooled to 50℃ at a rate of 2.0℃ / min. The polyethylene 2,5-furandicarboxylate fibers are then removed, washed, and dried to obtain purple polyethylene 2,5-furandicarboxylate fibers.

[0053] Comparative Example

[0054] 25 parts of 2,5-furandicarboxylic acid and 30 parts of ethylene glycol were mixed and esterified to produce ethylene glycol 2,5-furandicarboxylate and water. After removing the water, 7 parts of p-toluenesulfonic acid and 8 parts of N,N-methylenebisacrylamide were added to the ethylene glycol 2,5-furandicarboxylate and polycondensation was carried out under vacuum to synthesize polyethylene 2,5-furandicarboxylate. Polyethylene 2,5-furandicarboxylate fiber was obtained by melt spinning and expansion treatment.

[0055] Table 1: Comparison of various indicators between Examples 1-6 and the comparative examples

[0056]

[0057] The performance comparison of Examples 1-6 and the comparative examples shows that the bio-based colored polyethylene 2,5-furandicarboxylate fibers prepared using the dyeing method described in this invention can achieve a dyeing depth value (K / S) of over 25, a color fastness to rubbing of grade 3-4, a color fastness to staining of grade 4-5, a color fastness to washing of grade 4, and a color fastness to light of grade 4-5. This effectively enhances the dyeing activity and stability of pigments, thereby enabling the efficient synthesis of polyethylene 2,5-furandicarboxylate fibers in various colors.

[0058] In this invention, ultrasonic pretreatment of pigments and dyes reduces dye particle size, effectively improving dispersion uniformity and solubility in the dye bath. It also effectively removes oligomers generated on the surface of polyethylene 2,5-furandicarboxylate fibers and causes volume changes in their internal structure, generating more cavitation and microbubbles, which helps promote dyeing and improve dyeing efficiency. Furthermore, for the preparation reagents such as 2,5-furandicarboxylic acid and ethylene glycol, those skilled in the art can conventionally prepare or purchase them according to existing technology; this invention does not have special requirements regarding reagent selection or mixing.

[0059] In addition, the bio-based dyes of this invention belong to anthraquinone, naphthoquinone and other relatively stable natural dyes, which are all completely biodegradable. They have similar structures to traditional disperse dyes, small molecular weights and hydrophobicity, resulting in good dyeing effect. Moreover, some bio-based dyes also contain cationic groups, which can combine with the oxygen heterocycles on polyethylene 2,5-furandicarboxylate fibers to ensure high color fastness and colorfastness.

[0060] In addition, the metal mordants and carrier dyeing auxiliaries used in this invention are all environmentally friendly and biodegradable reagents that will not produce environmental hazards. Their dyeing process will not corrode existing dyeing and finishing equipment and is suitable for large-scale industrial production.

[0061] The technical solution, working process, and implementation effects of the present invention have been described in detail above. It should be noted that the described examples are only typical examples of the present invention. In addition, the present invention may have many other specific implementation methods. All technical solutions formed by equivalent substitution or equivalent transformation fall within the scope of protection claimed by the present invention.

Claims

1. A colored polyethylene 2,5-furandicarboxylate fiber, characterized in that, The raw materials used in its preparation, calculated by weight ratio, include: 2,5-Furandicarboxylic acid 25-90 parts 30-260 parts of ethylene glycol 7-12 parts of catalyst 7-12 parts of crosslinking agent 12-20 parts of pigment The molar ratio of 2,5-furandicarboxylic acid to ethylene glycol is 1:(1.2-2.8), the catalyst is one or more of tetrabutyl titanate, p-toluenesulfonic acid, cation exchange resin, and boron trifluoride, the crosslinking agent is one or more of divinylbenzene, diisocyanate, and N,N-methylenebisacrylamide, and the pigment is indigo. The fiber is produced by a method comprising the following steps: Step S1: 2,5-furandicarboxylic acid and ethylene glycol are mixed and subjected to esterification to produce ethylene glycol 2,5-furandicarboxylic acid and water; after removing the water, a catalyst and crosslinking agent are added to the ethylene glycol 2,5-furandicarboxylic acid, and a polycondensation reaction is carried out under vacuum to synthesize polyethylene 2,5-furandicarboxylic acid, which is then melt-spun and expanded to obtain polyethylene 2,5-furandicarboxylic acid fiber; Step S2: Perform a dyeing pretreatment on the polyethylene 2,5-furandicarboxylate fiber obtained in step S1. Add a treatment solution containing 2 g / L detergent POEA and 2 g / L sodium carbonate to the polyethylene 2,5-furandicarboxylate fiber. Soak the fiber at a temperature of 30-50℃ for 10-30 minutes. After washing with water, dry the fiber to remove the oil from the fiber surface, and obtain the dyed pretreated polyethylene 2,5-furandicarboxylate fiber. Step S3: Perform ultrasonic pretreatment on the pigment. The ultrasonic power is 500-700W, the ultrasonic frequency is 40-60HZ, the ultrasonic treatment temperature is 40-60℃, and the ultrasonic treatment time is 20-40min. Then, disperse and dissolve the pigment in deionized water at 40-60℃. Filter the pigment to remove plant residues. Add an acetic acid / sodium acetate buffer solution to adjust the pH value before using it for dyeing polyethylene 2,5-furandicarboxylate fibers. Step S4: The pretreated polyethylene 2,5-furandicarboxylate fibers are dyed under acidic conditions using the dye pretreated pigment from step S3. The dye concentration is 3.5 owf%, and the liquor ratio is 1:

20. The dyeing process involves heating the fibers to 80°C at a rate of 1.5°C / min, then heating them to 120°C at a rate of 0.8°C / min, holding the temperature for 40–60 min, and then cooling them to 50°C at a rate of 3.0°C / min. The polyethylene 2,5-furandicarboxylate fibers are then removed, washed, and dried to obtain colored polyethylene 2,5-furandicarboxylate fibers.

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