Colored poly (ethylene 2, 5-furandicarboxylate) fiber and preparation method thereof

Abstract

The invention discloses a colored poly (ethylene 2, 5-furandicarboxylate) fiber, which comprises 2, 5-furandicarboxylate, ethylene glycol, a catalyst, a cross-linking agent and a pigment, and the pigment is a bio-based dye or a coloring agent. The invention further discloses a preparation method of the colored polyethylene 2, 5-furandicarboxylate fiber, and the polyethylene 2, 5-furandicarboxylate fiber obtained by polymerizing and spinning polyethylene 2, 5-furandicarboxylate and ethylene glycol is efficiently dyed by utilizing the bio-based dye subjected to ultrasonic treatment. The dyeing carrier or the dyeing auxiliary is added in the dyeing process of the poly (ethylene 2, 5-furandicarboxylate) fiber, the affinity between the bio-based dye and the fiber can be improved, the dyeing performance is further improved, the pre-mordanting treatment is performed through the metal ions, the dye and the metal ions are matched, and the dyeing effect is improved. Therefore, the energy level interval of electron transition of a dye color development system is changed, and the color and color fastness of the dye are effectively changed.

Description

Technical Field

[0001] The invention relates to colored polyethylene 2,5-furandicarboxylate fiber and a preparation method thereof, belonging to the technical field of synthetic fiber material dyeing. Background Art

[0002] With the rapid development of world industrialization, human demand for petrochemical resources is also increasing. Therefore, the depletion of oil resources and its impact on the environment have become an unavoidable problem. In recent years, renewable resources and their application in polymers have gradually become the focus of attention. The use of plant resources to prepare monomers required for polymer synthesis has been proven to be a feasible approach. The development and application of polymer materials based on renewable resources has developed rapidly. Among them, polyethylene 2,5-furandicarboxylate fiber belongs to a new type of biodegradable bio-based fiber, and its main chain is composed of 2,5-furandicarboxylic acid and ethylene glycol units. 2,5-furandicarboxylic acid is a diacid derived from renewable resources of fructose and galactose in natural plants. It 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 polyethylene 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 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 with polyethylene 2,5-furandicarboxylate, the 2,5-furandicarboxylic acid unit structure is asymmetric, so the chain segments are not easy to flip; at the same time, the furan ring has a permanent dipole moment because the positive and negative charge centers do not overlap, thereby generating electrostatic force, which increases the interchain interaction force of polyethylene 2,5-furandicarboxylate, making it difficult for the polymer molecular chains to move, and the intermolecular steric hindrance is large. The glass transition temperature of polyethylene 2,5-furandicarboxylate is relatively high, usually around 88°C, and the fiber is light brown. The unique aggregated structure and appearance color make the fiber difficult to color, and there are few reports on its dyeing research and related patents. Therefore, it is necessary to propose a colored polyethylene 2,5-furandicarboxylate fiber and a preparation method thereof to solve the fiber and product dyeing problem caused by the structure and performance of the new green PEF fiber, so as to improve the chemical properties and applicability of the 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 the present invention is to solve the above problems and provide a colored polyethylene 2,5-furandicarboxylate fiber and a preparation method thereof.

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

[0006] Furthermore, in the above-mentioned colored polyethylene 2,5-furandicarboxylate fiber, the molar ratio of the 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 above-mentioned colored polyethylene 2,5-furandicarboxylate fiber, the bio-based dye is a natural dye having a cationic group or anthraquinone, naphthoquinone, etc., which is similar in structure to disperse dyes, has a very small molecular weight and a relatively stable hydrophobic structure; preferably, the bio-based dye is one or more of indigo, madder, safflower, lac, onion purple, turmeric, lithospermum and lutein.

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

[0012] Step (1): after mixing 2,5-furandicarboxylic acid and ethylene glycol, perform an esterification reaction to generate ethylene 2,5-furandicarboxylate and water; after removing the water, add a catalyst and a cross-linking agent to the ethylene 2,5-furandicarboxylate, perform a polycondensation reaction under vacuum conditions to synthesize polyethylene 2,5-furandicarboxylate, and obtain polyethylene 2,5-furandicarboxylate fiber through melt spinning and expansion treatment;

[0013] Step (2): performing dyeing pretreatment on the polyethylene 2,5-furandicarboxylate fiber obtained in step (1), adding a treatment solution containing 2 g / L of detergent POEA and 2 g / L of sodium carbonate to the polyethylene 2,5-furandicarboxylate fiber, soaking the fiber at a temperature of 30 to 50° C. for 10 to 30 minutes, washing with water and then drying to remove the oil on the fiber surface, thereby obtaining the polyethylene 2,5-furandicarboxylate fiber after dyeing pretreatment;

[0014] Step (3): pre-treating the pigment with ultrasound, with an ultrasound power of 500-700W, an ultrasound frequency of 40-60Hz, a temperature of 40-60°C, and an ultrasound treatment time of 20-40min, dispersing and dissolving the pigment with deionized water at a temperature of 40-60°C, filtering the pigment to remove plant residues, adding a pH regulator, acetic acid / sodium acetate buffer solution to adjust the pH value, and then using the pigment for dyeing polyethylene 2,5-furandicarboxylate fiber;

[0015] Step (4): using the pigment pre-treated by ultrasonic wave in step (3) to dye the pre-treated polyethylene 2,5-furandicarboxylate fiber under acidic conditions, the dyeing method is one of a high temperature and high pressure dyeing method, an environmentally friendly metal mordant dyeing method, an ultrasonic wave dyeing method, an ultrasonic wave carrier dyeing method, and an ultrasonic wave carrier dyeing method. The dyeing concentration is 3.5owf%, and the bath ratio is 1:20. The dyeing treatment is heated to 80°C at a heating rate of 1.5°C / min, and then heated to 120°C at a heating rate of 0.8°C / min, and kept warm for 40 to 60 minutes. After cooling to 50°C at a rate of 3.0°C / min, the polyethylene 2,5-furandicarboxylate fiber is taken out for washing and drying to obtain colored polyethylene 2,5-furandicarboxylate fiber.

[0016] Furthermore, the preparation method of the above-mentioned colored polyethylene 2,5-furandicarboxylate fiber, wherein: in the step S4, the environmentally friendly metal mordant assisted dyeing method includes an environmentally friendly metal mordant, and the environmentally friendly metal mordant is one or more of a heavy metal-free zinc salt mordant, a heavy metal-free iron salt mordant, a heavy metal-free aluminum salt mordant and a heavy metal-free titanium salt mordant.

[0017] Furthermore, the preparation method of the above-mentioned colored polyethylene 2,5-furandicarboxylate fiber, wherein: in the step S4, the ultrasonic treatment assisted dyeing and normal pressure dyeing method includes dyeing auxiliaries, and the dyeing auxiliaries are one or more of sodium lignin sulfonate, dispersant NNO, dispersant MF and dispersant CNF, which improves the binding force between the dye and the fiber.

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

[0019] Furthermore, the preparation method of the above-mentioned colored polyethylene 2,5-furandicarboxylate fiber, wherein: in the step S4, the high temperature and high pressure dyeing method is to dye without adding dyeing auxiliary agents and through a sealed dyeing tank, the pressure in the sealed dyeing tank is greater than 101.325 kPa, and the dye solution temperature is 120-130°C.

[0020] In this way, by adopting the technical solution of the present invention, ultrasonic pretreatment is performed on the pigment dye to reduce the particle size of the dye, effectively improving the dispersion uniformity and solubility in the dye solution; it can also effectively remove the oligomers generated on the surface of the polyethylene 2,5-furandicarboxylate fiber, and cause the volume of its internal structure to change, thereby generating more cavitations, microbubbles, etc., which helps to promote dyeing and improve dyeing efficiency.

[0021] Compared with the prior art, after adopting the technical scheme of the present invention, the pre-mordanting treatment is carried out by metal ions to form a complex between the dye and the metal ions, thereby changing the energy level interval of the electronic transition of the dye color development system, and then effectively changing the color and dyeing fastness of the dye; adding a dyeing carrier or a dyeing auxiliary agent during the dyeing process of polyethylene 2,5-furandicarboxylate fiber can increase the affinity between the bio-based dye and the fiber, and further improve the dyeing performance. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with specific examples, but it should not be understood that the protection scope of the above subject matter of the present invention is limited to the following examples. Among them, the raw materials used are commercially available or homemade using methods known in the industry.

[0023] Example 1

[0024] Step (1) 25 parts of 2,5-furandicarboxylic acid and 30 parts of ethylene glycol are mixed, and then subjected to esterification reaction to generate ethylene 2,5-furandicarboxylate and water; after removing the water, 7 parts of tetrabutyl titanate and 8 parts of diisocyanate are added to the ethylene 2,5-furandicarboxylate, and polycondensation reaction is performed under vacuum conditions to synthesize polyethylene 2,5-furandicarboxylate, and polyethylene 2,5-furandicarboxylate fibers are obtained through melt spinning and expansion treatment.

[0025] Step (2) pre-treating the polyethylene 2,5-furandicarboxylate fiber obtained in step (1) by adding a treatment solution containing 2 g / L of detergent POEA and 2 g / L of sodium carbonate to the polyethylene 2,5-furandicarboxylate fiber, soaking it at 40°C for 20 minutes, washing it with water and then drying it to remove the oil on the fiber surface, thereby obtaining the polyethylene 2,5-furandicarboxylate fiber after the pre-treating.

[0026] Step (3) pre-treating the indigo dye with ultrasound, with an ultrasound power of 500-700 W, an ultrasound frequency of 50 Hz, a temperature of 50° C., and an ultrasound treatment time of 30 min, dispersing and dissolving the pigment with deionized water at a temperature of 50° C., filtering the pigment to remove plant residues, and adding a pH regulator, acetic acid / sodium acetate buffer solution, to adjust the pH value before using the pigment for dyeing polyethylene 2,5-furandicarboxylate fiber.

[0027] Step (4) uses the indigo dye in step (3) to dye the polyethylene 2,5-furandicarboxylate fiber that has been pre-deoiled by ultrasonic wave under acidic conditions, with a dyeing concentration of 3.5 (owf%) and a bath ratio of 1:20. The temperature is raised to 80°C at a heating rate of 1.5°C / min, then raised to 120°C at a heating rate of 0.8°C / min, and kept warm for 50 minutes. After cooling to 50°C at a rate of 3.0°C / min, the polyethylene 2,5-furandicarboxylate fiber is taken out for washing and drying to obtain blue ethylene 2,5-furandicarboxylate fiber.

[0028] Example 2

[0029] Step (1) 25 parts of 2,5-furandicarboxylic acid and 30 parts of ethylene glycol are mixed, and then subjected to esterification reaction to generate ethylene 2,5-furandicarboxylate and water; after removing the water, 7 parts of boron trifluoride and 8 parts of divinylbenzene are added to the ethylene 2,5-furandicarboxylate, and polycondensation reaction is performed under vacuum conditions to synthesize polyethylene 2,5-furandicarboxylate, and polyethylene 2,5-furandicarboxylate fibers are obtained through melt spinning and expansion treatment.

[0030] Step (2) pre-treating the polyethylene 2,5-furandicarboxylate fiber obtained in step (1) by adding a treatment solution containing 2 g / L of detergent POEA and 2 g / L of sodium carbonate to the polyethylene 2,5-furandicarboxylate fiber, soaking it at 40°C for 20 minutes, washing it with water and then drying it to remove the oil on the fiber surface, thereby obtaining the polyethylene 2,5-furandicarboxylate fiber after the pre-treating.

[0031] Step (3) pre-treating the lac insect dye with ultrasound, with an ultrasound power of 500 W, an ultrasound frequency of 50 Hz, a temperature of 50° C., and an ultrasound treatment time of 30 min; dispersing and dissolving the pigment with deionized water at a temperature of 50° C.; filtering the pigment to remove plant residues; and adding a pH regulator, acetic acid / sodium acetate buffer solution, to adjust the pH value before using the pigment for dyeing polyethylene 2,5-furandicarboxylate fiber.

[0032] Step (4) dyes the polyethylene 2,5-furandicarboxylate fiber that has been pre-deoiled by ultrasonic wave using lac insect dye in step (3) under acidic conditions, with a dyeing concentration of 4.0 (owf%) and a bath ratio of 1:15. The temperature is raised to 80°C at a heating rate of 1.5°C / min, then raised to 125°C at a heating rate of 1.0°C / min, and kept warm for 60 minutes. The polyethylene 2,5-furandicarboxylate fiber is taken out and washed and dried to obtain orange-red polyethylene 2,5-furandicarboxylate fiber.

[0033] Example 3

[0034] Step (1) 25 parts of 2,5-furandicarboxylic acid and 30 parts of ethylene glycol are mixed, and then subjected to esterification reaction to generate ethylene 2,5-furandicarboxylate and water; after removing the water, 7 parts of tetrabutyl titanate and 8 parts of diisocyanate are added to the ethylene 2,5-furandicarboxylate, and polycondensation reaction is performed under vacuum conditions to synthesize polyethylene 2,5-furandicarboxylate, and polyethylene 2,5-furandicarboxylate fibers are obtained through melt spinning and expansion treatment.

[0035] Step (2) pre-treating the polyethylene 2,5-furandicarboxylate fiber obtained in step (1) by adding a treatment solution containing 2 g / L of detergent POEA and 2 g / L of sodium carbonate to the polyethylene 2,5-furandicarboxylate fiber, soaking it at 40°C for 20 minutes, washing it with water and then drying it to remove the oil on the fiber surface, thereby obtaining the polyethylene 2,5-furandicarboxylate fiber after the pre-treating.

[0036] Step (3) pre-treating the madder dye with ultrasound, with an ultrasound power of 500 W, an ultrasound frequency of 50 Hz, a temperature of 50° C., and an ultrasound treatment time of 30 min, dispersing and dissolving the pigment with deionized water at a temperature of 50° C., filtering the pigment to remove plant residues, adding a pH regulator, acetic acid / sodium acetate buffer solution to adjust the pH value, and then using it for dyeing polyethylene 2,5-furandicarboxylate fiber.

[0037] Step (4) uses madder dye in step (3) to dye the polyethylene 2,5-furandicarboxylate fiber that has been pre-deoiled by ultrasonic wave under acidic conditions, with a dyeing concentration of 4.0 (owf%) and a bath ratio of 1:20. The temperature is raised to 80°C at a heating rate of 1.5°C / min, then raised to 130°C at a heating rate of 1.0°C / min, and kept warm for 50 minutes. After cooling to 50°C at a rate of 3.0°C / min, the polyethylene 2,5-furandicarboxylate fiber is taken out for washing and drying to obtain dark red polyethylene 2,5-furandicarboxylate fiber.

[0038] Example 4

[0039] Step (1) 25 parts of 2,5-furandicarboxylic acid and 30 parts of ethylene glycol are mixed, and then subjected to esterification reaction to generate ethylene 2,5-furandicarboxylate and water; after removing the water, 7 parts of tetrabutyl titanate and 8 parts of diisocyanate are added to the ethylene 2,5-furandicarboxylate, and polycondensation reaction is performed under vacuum conditions to synthesize polyethylene 2,5-furandicarboxylate, and polyethylene 2,5-furandicarboxylate fibers are obtained through melt spinning and expansion treatment.

[0040] Step (2) pre-dyeing the polyethylene 2,5-furandicarboxylate fiber obtained in step (1), adding a treatment solution containing 2 g / L of detergent POEA and 2 g / L of sodium carbonate to the polyethylene 2,5-furandicarboxylate fiber, soaking it at 40°C for 20 min, washing it with water and then drying it to remove the oil on the fiber surface, and performing iron salt pre-mordant dyeing on the deoiled polyethylene 2,5-furandicarboxylate fiber, wherein the mordant concentration is 0.60×10 -3 mol / g, temperature 60°C, time 30min, and obtain the polyethylene 2,5-furandicarboxylate fiber after dyeing pretreatment.

[0041] Step (3) pre-treating the lutein with ultrasound, with an ultrasound power of 500 W, an ultrasound frequency of 50 Hz, a temperature of 50° C., and an ultrasound treatment time of 30 min. The pigment is then dispersed and dissolved in deionized water at a temperature of 50° C., the pigment is filtered to remove plant residues, and a pH regulator, acetic acid / sodium acetate buffer solution, is added to adjust the pH value to 5.0 before being used for dyeing polyethylene 2,5-furandicarboxylate fiber.

[0042] Step (4) uses lutein in step (3) to dye the polyethylene 2,5-furandicarboxylate fiber that has been pre-deoiled by ultrasonic wave under acidic conditions, with a dyeing concentration of 4.0 (owf%) and a bath ratio of 1:15. The temperature is raised to 70°C at a heating rate of 1.5°C / min, then raised to 100°C at a heating rate of 0.8°C / min, and kept warm for 60 minutes. After cooling to 50°C at a rate of 2.0°C / min, the polyethylene 2,5-furandicarboxylate fiber is taken out for washing and drying to obtain yellow polyethylene 2,5-furandicarboxylate fiber.

[0043] Example 5

[0044] Step (1) 25 parts of 2,5-furandicarboxylic acid and 30 parts of ethylene glycol are mixed, and then subjected to esterification reaction to generate ethylene 2,5-furandicarboxylate and water; after removing the water, 7 parts of tetrabutyl titanate and 8 parts of diisocyanate are added to the ethylene 2,5-furandicarboxylate, and polycondensation reaction is performed under vacuum conditions to synthesize polyethylene 2,5-furandicarboxylate, and polyethylene 2,5-furandicarboxylate fibers are obtained through melt spinning and expansion treatment.

[0045] Step (2) pre-treating the polyethylene 2,5-furandicarboxylate fiber obtained in step (1) by adding a treatment solution containing 2 g / L of detergent POEA and 2 g / L of sodium carbonate to the polyethylene 2,5-furandicarboxylate fiber, soaking it at 40°C for 20 minutes, washing it with water and then drying it to remove the oil on the fiber surface, thereby obtaining the polyethylene 2,5-furandicarboxylate fiber after the pre-treating.

[0046] Step (3) pre-treating the curcumin dye with ultrasound, with an ultrasound power of 500 W, an ultrasound frequency of 50 Hz, a temperature of 50° C., and an ultrasound treatment time of 30 min, dispersing and dissolving the pigment with deionized water at a temperature of 50° C., filtering the pigment to remove plant residues, adding a pH regulator acetic acid / sodium acetate buffer solution to adjust the pH value, and then using the pigment for dyeing polyethylene 2,5-furandicarboxylate fiber.

[0047] Step (4) uses the curcumin dye in step (3) to dye the polyethylene 2,5-furandicarboxylate fiber that has been pre-deoiled by ultrasonic wave under acidic conditions, the dye pH value is 5.0-6.0, the dyeing concentration is 5.0 (owf%), the bath ratio is 1:15, the temperature is increased to 70°C at a heating rate of 1.5°C / min, then increased to 100°C at a heating rate of 0.8°C / min, kept warm for 60 minutes, cooled to 50°C at a rate of 2.0°C / min, and the polyethylene 2,5-furandicarboxylate fiber is taken out for washing and drying to obtain orange-yellow polyethylene 2,5-furandicarboxylate fiber.

[0048] Example 6

[0049] Step (1) 25 parts of 2,5-furandicarboxylic acid and 30 parts of ethylene glycol are mixed, and then subjected to esterification reaction to generate ethylene 2,5-furandicarboxylate and water; after removing the water, 7 parts of cation exchange resin and 8 parts of diisocyanate are added to the ethylene 2,5-furandicarboxylate, and polycondensation reaction is performed under vacuum conditions to synthesize polyethylene 2,5-furandicarboxylate, and polyethylene 2,5-furandicarboxylate fibers are obtained through melt spinning and expansion treatment.

[0050] Step (2) pre-treating the polyethylene 2,5-furandicarboxylate fiber obtained in step (1) by adding a treatment solution containing 2 g / L of detergent POEA and 2 g / L of sodium carbonate to the polyethylene 2,5-furandicarboxylate fiber, soaking it at 40°C for 20 minutes, washing it with water and then drying it to remove the oil on the fiber surface, thereby obtaining the polyethylene 2,5-furandicarboxylate fiber after the pre-treating.

[0051] Step (3) performs ultrasonic pretreatment on the onion purple dye, with an ultrasonic power of 500 W, an ultrasonic frequency of 50 Hz, a temperature of 50° C., and an ultrasonic treatment time of 30 min, and then disperses and dissolves the pigment in deionized water at a temperature of 50° C., filters the pigment to remove plant residues, and adds a dyeing aid T2 (concentration of 20 g / L) into the filtered onion purple dye solution, stirs the solution evenly, and then uses the solution for dyeing polyethylene 2,5-furandicarboxylate fiber.

[0052] Step (4) uses the onion purple dye in step (3) to dye the polyethylene 2,5-furandicarboxylate fiber that has been pre-deoiled by ultrasonic wave under acidic conditions, the dye pH value is 5.0-6.0, the dyeing concentration is 4.0 (owf%), the bath ratio is 1:15, the temperature is increased to 70°C at a heating rate of 1.5°C / min, then increased to 100°C at a heating rate of 0.8°C / min, and kept warm for 70 minutes. After cooling to 50°C at a rate of 2.0°C / min, the polyethylene 2,5-furandicarboxylate fiber is taken out for washing and drying to obtain purple polyethylene 2,5-furandicarboxylate fiber.

[0053] Comparative Example

[0054] After 25 parts of 2,5-furandicarboxylic acid and 30 parts of ethylene glycol are mixed, an esterification reaction is carried out to generate ethylene 2,5-furandicarboxylate and water; after removing the water, 7 parts of p-toluenesulfonic acid and 8 parts of N,N-methylenebisacrylamide are added to the ethylene 2,5-furandicarboxylate, and a polycondensation reaction is carried out under vacuum conditions to synthesize polyethylene 2,5-furandicarboxylate, and polyethylene 2,5-furandicarboxylate fiber is obtained through melt spinning and expansion treatment.

[0055] Table 1: Comparison of various indicators of Examples 1 to 6 and Comparative Examples

[0056]

[0057] From the performance comparison of Examples 1 to 6 and the comparative example, it can be seen that the bio-based colored polyethylene 2,5-furandicarboxylate fiber prepared by the dyeing method described in the present invention can achieve a fiber dyeing depth value K / S of more than 25, a color fastness to rubbing of 3-4, a color fastness to staining of 4-5, a color fastness to washing of 4, and a color fastness to sunlight of 4-5; the dyeing activity and stability of the pigment can be effectively improved, thereby realizing the efficient synthesis of polyethylene 2,5-furandicarboxylate fibers of various colors.

[0058] In the technical solution of the present invention, ultrasonic pretreatment is performed on the pigment dye to reduce the particle size of the dye, effectively improving the dispersion uniformity and solubility in the dye solution; it can also effectively remove the oligomers generated on the surface of the polyethylene 2,5-furandicarboxylate fiber, and cause the volume change of its internal structure, generate more cavitations, microbubbles, etc., which help promote dyeing and improve dyeing efficiency. In addition, for the preparation reagents such as 2,5-furandicarboxylic acid and ethylene glycol, ordinary technicians in this field can make conventional configurations or purchase them according to the existing technology, and this case has no special requirements for the selection and mixed use of the reagents.

[0059] In addition, the bio-based dyes of the present invention belong to relatively stable natural dyes of structural types such as anthraquinones and naphthoquinones, which are all completely biodegradable, have a similar structure to traditional disperse dyes, have a very small molecular weight, are hydrophobic, and have a good dyeing effect; moreover, some bio-based dyes also contain cationic groups, which can be combined with the oxygen heterocycles on the polyethylene 2,5-furandicarboxylate fiber to ensure high coloring and dyeing fastness.

[0060] In addition, the metal mordant, carrier dyeing aid, etc. used in the present invention are all environmentally friendly and degradable reagents, which will not produce environmental hazards, and the dyeing process will not corrode existing dyeing and finishing equipment, and are suitable for industrial large-scale production.

[0061] The technical scheme, working process and implementation effect of the present invention are described in detail above. It should be noted that what is described is only a typical example of the present invention. In addition, the present invention may also have many other specific implementation methods. Any technical scheme formed by equivalent replacement or equivalent transformation falls within the scope of protection required by the present invention.

Claims

1. A colored polyethylene 2,5-furandicarboxylate fiber, characterized in that: Calculated by weight, the raw materials for its preparation include: 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 a bio-based dye or colorant.

2. The colored polyethylene 2,5-furandicarboxylate fiber according to claim 1, characterized in that: The bio-based dye is a natural dye having a cationic group or anthraquinone or naphthoquinone structure similar to disperse dyes, a small molecular weight, and a relatively stable hydrophobic structure.

3. The colored polyethylene 2,5-furandicarboxylate fiber according to claim 1, characterized in that: The bio-based dye is one or more of indigo, madder, safflower, lac, onion purple, turmeric, lithospermum and lutein.

4. The method for preparing a colored polyethylene 2,5-furandicarboxylate fiber according to claim 1, characterized in that The following steps are involved: Step S1: after mixing 2,5-furandicarboxylic acid and ethylene glycol, perform an esterification reaction to generate ethylene 2,5-furandicarboxylate and water; after removing the water, add a catalyst and a cross-linking agent to the ethylene 2,5-furandicarboxylate, perform a polycondensation reaction under vacuum conditions to synthesize polyethylene 2,5-furandicarboxylate, and obtain polyethylene 2,5-furandicarboxylate fiber through melt spinning and expansion treatment; Step S2: performing dyeing pretreatment on the polyethylene 2,5-furandicarboxylate fiber obtained in step S1, adding a treatment solution containing 2 g / L of detergent POEA and 2 g / L of sodium carbonate to the polyethylene 2,5-furandicarboxylate fiber, soaking the fiber at a temperature of 30 to 50° C. for 10 to 30 minutes, washing with water and then drying to remove the oil on the fiber surface, thereby obtaining the polyethylene 2,5-furandicarboxylate fiber after dyeing pretreatment; Step S3: performing ultrasonic pretreatment on the pigment, with an ultrasonic power of 500-700W, an ultrasonic frequency of 40-60HZ, a temperature of 40-60°C, and an ultrasonic treatment time of 20-40min, and then dispersing and dissolving the pigment with deionized water at a temperature of 40-60°C, filtering the pigment to remove plant residues, adding a pH regulator acetic acid / sodium acetate buffer solution to adjust the pH value, and then using it for dyeing polyethylene 2,5-furandicarboxylate fiber; Step S4: using the pigment pre-treated by ultrasonic wave in step S3 to dye the pre-treated polyethylene 2,5-furandicarboxylate fiber under acidic conditions, the dyeing method is one of a high temperature and high pressure dyeing method, an environmentally friendly metal mordant dyeing method, an ultrasonic wave dyeing method, and an ultrasonic wave carrier dyeing method, the dyeing concentration is 3.5owf%, the bath ratio is 1:20, the dyeing treatment is heated to 80°C at a heating rate of 1.5°C / min, and then heated to 120°C at a heating rate of 0.8°C / min, and kept warm for 40 to 60 minutes. After cooling to 50°C at a rate of 3.0°C / min, the polyethylene 2,5-furandicarboxylate fiber is taken out for washing and drying to obtain colored polyethylene 2,5-furandicarboxylate fiber.

5. The method for preparing a colored polyethylene 2,5-furandicarboxylate fiber according to claim 4, characterized in that: In step S4, when the dyeing method using an environmentally friendly metal mordant is adopted, the environmentally friendly metal mordant used is one or more of a zinc salt mordant free of heavy metals, an iron salt mordant free of heavy metals, an aluminum salt mordant free of heavy metals, and a titanium salt mordant free of heavy metals.

6. The method for preparing a colored polyethylene 2,5-furandicarboxylate fiber according to claim 4, characterized in that: In the step S4, when the normal pressure dyeing method is adopted with ultrasonic treatment as the auxiliary dyeing agent, the dyeing auxiliary agent used is one or more of sodium lignin sulfonate, dispersant NNO, dispersant MF and dispersant CNF.

7. The method for preparing colored polyethylene 2,5-furandicarboxylate fiber according to claim 4, characterized in that: In step S4, when the normal pressure dyeing method is performed by using ultrasonic treatment of the carrier to assist dyeing, the dyeing carrier used is one or more of the natural dyeing auxiliaries T258, T2 and T286.

8. The method for preparing colored polyethylene 2,5-furandicarboxylate fiber according to claim 4, characterized in that: In step S4, when a high temperature and high pressure dyeing method is adopted, no dyeing auxiliary agent is added and dyeing is performed in a sealed dyeing tank, the pressure in the sealed dyeing tank is greater than 101.325 kPa, and the temperature of the dye solution is 120-130°C.

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