Highly uniform-dyeing high-performance polyester suitable for regular temperature dyeing and a preparation process thereof

Abstract

The application relates to the technical field of high-performance polyester and discloses high-dyeing-uniformity high-performance polyester suitable for conventional temperature dyeing and a preparation process thereof, which comprises the following steps: terephthalic acid, ethylene glycol, a modified monomer and a catalyst are mixed to carry out esterification reaction, a stabilizer and modified nanoparticles are added to carry out polycondensation reaction, and after discharge, water cooling and granulation, modified PET chips are obtained; the modified PET chips are dried, then are subjected to melt spinning, cooling forming and stretching to obtain high-dyeing-uniformity high-performance polyester. The modified PET chips are prepared by using terephthalic acid and ethylene glycol as raw materials and by adding a modified monomer and modified nanoparticles, and then the modified PET chips are subjected to melt spinning, cooling forming and stretching to obtain polyester fibers which have high dyeing uniformity when dyed at conventional temperature, and the defects of insufficient dyeing uniformity, decreased fiber mechanical property and poor washing fastness of the polyester fibers at conventional temperature and under normal pressure are solved.

Description

Technical Field

[0001] This invention relates to the field of high-performance polyester technology, specifically to a high-performance polyester with high level dyeing properties suitable for conventional temperature dyeing and its preparation process. Background Technology

[0002] Polyester fiber (polyethylene terephthalate fiber) has become the most produced and widely used synthetic fiber due to its advantages such as high tensile strength, good elasticity, excellent thermal stability, and resistance to chemical corrosion. However, polyester fiber has high crystallinity, orientation degree, and glass transition temperature, lacks polar groups, and is highly hydrophobic, resulting in poor dyeing performance. Currently, polyester fiber has high requirements for dyeing conditions. Only under high temperature (120-130℃) conditions can the dyeing problem of polyester be solved. However, high temperature and high pressure dyeing consumes a lot of energy and requires a large investment in equipment. Moreover, high temperature conditions can easily cause strong damage to the natural fiber components in polyester textiles. Therefore, how to reduce the dyeing temperature of polyester fiber has become a key problem that printing and dyeing workers urgently need to solve.

[0003] Existing dyes penetrate unevenly into polyester fibers, easily causing color spots and color differences, which affect the appearance quality of the fabric. Moreover, polyester fibers that are easy to dye under normal temperature and pressure are often modified by introducing a third monomer, which results in insufficient dyeing uniformity, decreased fiber mechanical properties, and poor wash fastness. Therefore, how to improve dyeing performance while maintaining or improving the fiber's breaking strength and dimensional stability is also one of the technical challenges. Summary of the Invention

[0004] This invention provides a high-performance polyester with high uniformity suitable for conventional temperature dyeing and its preparation process, which solves the problems of insufficient dyeing uniformity, decreased fiber mechanical properties, and poor wash fastness in conventional temperature dyeing of polyester.

[0005] The technical solution of this invention:

[0006] A process for preparing high-level dyeing performance polyester suitable for conventional temperature dyeing includes the following steps:

[0007] S1. Terephthalic acid, ethylene glycol, modified monomers and catalyst are mixed and esterified. Stabilizers and modified nanoparticles are added and polycondensation is carried out. After discharge, water cooling and pelletizing, modified PET chips are obtained.

[0008] S2. After drying, modified PET chips are melt-spun, cooled and shaped, and stretched to obtain high-performance polyester with high even dyeing properties.

[0009] The modified monomer is obtained by reacting polyethylene glycol, sodium isophthalate-5-sulfonate, ethylene glycol, carboxymethyl-β-cyclodextrin and 1-carboxylated o-carborane.

[0010] The modified nanoparticles are obtained by synthesizing a porous carbon layer on the surface of nano-montmorillonite and then modifying the surface with a silane coupling agent.

[0011] Further, in step S1, the mass ratio of terephthalic acid, ethylene glycol, modified monomer, catalyst, stabilizer and modified nanoparticles is (80-90):(8-12):(4-6):(0.05-0.1):(0.03-0.05):(3-5).

[0012] Further, in step S1, the catalyst is tetrabutyl titanate and the stabilizer is triphenyl phosphate.

[0013] Furthermore, in step S1, the esterification reaction temperature is 220-240℃, the esterification reaction time is 3-4h, and the esterification reaction is carried out under nitrogen protection.

[0014] Further, in step S1, the polycondensation reaction specifically involves: polycondensation at a temperature of 240-250℃ and a vacuum degree of 500-1000Pa for 1-1.5 hours, followed by a polycondensation reaction at a temperature of 260-270℃ and a vacuum degree of 40-50Pa for 2-3 hours.

[0015] Further, in step S2, the melt spinning is carried out in a melt spinning machine, the spinning temperature is 280-295℃, the spinning speed is 1000-1500m / min, and the spinneret orifice diameter is 0.25-0.3mm.

[0016] Furthermore, in step S2, the stretching ratio is 3-3.5, and the stretching temperature is 80-90℃.

[0017] Further, in step S2, the drying specifically involves drying at 70-90℃ for 10-12 hours.

[0018] Furthermore, the modified monomer is specifically prepared by the following steps:

[0019] Polyethylene glycol, sodium isophthalate-5-sulfonate, and ethylene glycol were mixed and placed in a reaction vessel. Under nitrogen protection, the mixture was reacted at 160-180℃ for 2-3 hours. Then, it was added to a 5% sodium hydroxide aqueous solution and stirred until homogeneous. Carboxymethyl-β-cyclodextrin and 1-carboxy-o-carborane were added, and the mixture was stirred at 100-120℃ for 1-1.5 hours. After cooling to room temperature, the mixture was filtered to obtain the modified monomer.

[0020] Furthermore, in the above reaction process, the carboxyl groups contained in sodium isophthalic acid-5-sulfonate can undergo esterification with the hydroxyl groups of polyethylene glycol and ethylene glycol to form monomers containing hydrophilic polyether groups and sulfonic acid groups. In addition, during the reaction process, the carboxyl groups contained in carboxymethyl-β-cyclodextrin and 1-carboxy-o-carborane can also participate in the esterification reaction, so that carboxymethyl-β-cyclodextrin and 1-carboxy-o-carborane are grafted onto the monomers to obtain modified monomers.

[0021] Further, the mass ratio of polyethylene glycol, sodium isophthalate-5-sulfonate, ethylene glycol, sodium hydroxide aqueous solution, carboxymethyl-β-cyclodextrin and 1-carboxy-o-carborane is (1-1.5):(1-1.5):(1.5-2.5):(40-50):(0.5-1):(0.5-1).

[0022] Furthermore, the modified nanoparticles are specifically prepared by the following steps:

[0023] A1. Add nano-montmorillonite, glucose and tannic acid to ethanol, stir, filter, dry, place in a tube furnace, add potassium hydroxide solution, purge with nitrogen, carbonize at 750-850℃ for 3-5h, cool to room temperature, remove, wash and dry to obtain nano-montmorillonite loaded with porous carbon.

[0024] A2. Add porous carbon-loaded nano-montmorillonite to ethanol and deionized water, stir until homogeneous, add silane coupling agent, stir the reaction, cool to room temperature, filter, wash, and dry to obtain modified nanoparticles.

[0025] Furthermore, in the A1 reaction process described above, after a porous carbon layer is synthesized on the surface of nano-montmorillonite, tannic acid, containing a large number of phenolic hydroxyl groups, acts as a linker, enabling glucose to be adsorbed onto the surface of nano-montmorillonite. Upon high-temperature carbonization, the glucose decomposes to form a dense carbon layer. Potassium hydroxide solution, acting as an activator, forms channels on the surface of the dense carbon layer, thus achieving the synthesis of a porous carbon layer on the surface of nano-montmorillonite, resulting in nano-montmorillonite with a porous carbon layer.

[0026] Furthermore, during the A2 reaction process described above, the hydroxyl groups generated by the hydrolysis of the silane coupling agent can chemically bond with the hydroxyl groups on the surface of the nano-montmorillonite supported on the porous carbon layer, thereby grafting the silane coupling agent onto the surface of the nano-montmorillonite supported on the porous carbon layer to obtain modified nanoparticles.

[0027] Further, in step A1, the ratio of the amount of nano-montmorillonite, glucose, tannic acid, ethanol and potassium hydroxide solution is (2-3):(1-1.5):(0.3-0.5):(80-100):(4-6).

[0028] Further, in step A2, the mass ratio of the nano-montmorillonite loaded with porous carbon, ethanol, deionized water and silane coupling agent is (3-4):(25-35):(8-12):(0.6-1).

[0029] The present invention has the following beneficial effects:

[0030] (1) In the technical solution of this invention, carboxymethyl-β-cyclodextrin and 1-carboxy-o-carborane are grafted onto a monomer formed by the reaction of polyethylene glycol, sodium isophthalate-5-sulfonate, and ethylene glycol. On the one hand, β-cyclodextrin is dispersed on the modified monomer molecular chain, and its internal cavity is hydrophobic and its external surface is hydrophilic, which can form an inclusion complex with disperse dyes through hydrophobic interaction, so that the disperse dyes are uniformly adsorbed on the polyester fibers. On the other hand, 1-carboxy-o-carborane contains a stable cage-like structure and has high thermal stability. Therefore, 1-carboxymethyl-β-cyclodextrin and 1-carboxy-o-carborane are grafted onto a monomer formed by the reaction of polyethylene glycol, sodium isophthalate-5-sulfonate, and ethylene glycol. The grafting of β-carborane onto the monomer molecular chain improves the thermal stability of the monomer, preventing it from being prone to degradation and breakage during melt spinning, which would affect the high level dyeing performance of polyester fibers at normal temperatures. In addition, the modified monomer molecular chain contains hydrophilic polyether and sulfonic acid groups. The sulfonic acid groups and ether bonds can enhance hydrophilicity and polarity, making polyester fibers easier to swell and dyes easier to adsorb. At normal temperatures, the chain segment movement and micro-gap opening of polyester fibers increase the dye diffusion rate, resulting in high level dyeing performance of polyester fibers at normal temperatures.

[0031] (2) In the technical solution of the present invention, a porous carbon layer is synthesized on the surface of nano-montmorillonite. On the one hand, the layered structure of nano-montmorillonite can expand the molecular chain of polyester fiber, increase the free volume, and reduce the glass transition temperature of polyester fiber, so that disperse dye can be dyed at a normal temperature (95-100℃). Moreover, nano-montmorillonite is uniformly dispersed in the polyester fiber matrix to form nanoscale channels, which improves the dye diffusion rate and uniformity. At the same time, the mechanical properties of polyester fiber are improved. On the other hand, the porous carbon layer synthesized on the surface of nano-montmorillonite has a uniform porous structure, which increases the dye diffusion channels and reduces the dye diffusion resistance, so that polyester fiber has high uniform dyeing performance when dyed at a normal temperature. In addition, the double adsorption of nano-montmorillonite and porous carbon layer avoids the polyester fiber from fading and discoloration, so that the polyester fiber has high color fastness.

[0032] (3) In the technical solution of the present invention, the silane coupling agent is grafted onto the surface of the nano-montmorillonite loaded with porous carbon layer, so that the nano-montmorillonite loaded with porous carbon layer contains reactive double bonds. During the polycondensation process, tetrabutyl titanate acts as a catalyst, and the reactive double bonds can participate in the synthesis of PET chips and form a cross-linked network structure in the PET chips, so that the modified nanoparticles are grafted onto the molecular chain of PET chips, improving the dispersion and interaction force of the modified nanoparticles on polyester fibers, thereby improving the high level dyeing performance of polyester fibers at normal temperature. Moreover, the cross-linked network structure formed by the modified nanoparticles in polyester fibers can absorb and weaken the stress generated by external forces, inhibit crack propagation, and improve the mechanical properties of polyester fibers.

[0033] (4) In the technical solution of the present invention, terephthalic acid and ethylene glycol are used as raw materials, and modified monomers and modified nanoparticles are added to prepare modified PET chips. After melt spinning, cooling and forming and stretching, the resulting polyester fibers have high uniform dyeing performance when dyed at normal temperature. This solves the defects of insufficient dyeing uniformity, decreased fiber mechanical properties and poor wash fastness of polyester fibers under normal temperature and pressure. Detailed Implementation

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0035] The raw materials used in the embodiments of this invention are shown below, and all reagents used are analytical grade.

[0036] The catalyst is tetrabutyl titanate, and the stabilizer is triphenyl phosphate.

[0037] The particle size of nano-montmorillonite is 50 nm;

[0038] The silane coupling agent is KH570 (γ-methacryloyloxypropyltrimethoxysilane);

[0039] Polyethylene glycol has a molecular weight of 1500.

[0040] Carboxymethyl-β-cyclodextrin, catalog number 779873-100G, was purchased from Merck.

[0041] 1-Carboxy-o-carborane, model number 8947145, was purchased from Hubei Jianchu Biomedical Co., Ltd.

[0042] Example 1

[0043] A process for preparing high-level dyeing performance polyester suitable for conventional temperature dyeing includes the following steps:

[0044] S1. Terephthalic acid, ethylene glycol, modified monomers, and tetrabutyl titanate are mixed and subjected to esterification reaction. Triphenyl phosphate and modified nanoparticles are added and subjected to polycondensation reaction. After discharge, water cooling, and pelletizing, modified PET chips are obtained. The mass ratio of terephthalic acid, ethylene glycol, modified monomers, tetrabutyl titanate, triphenyl phosphate, and modified nanoparticles is 80:8:4:0.05:0.03:3.

[0045] The esterification reaction temperature was 220℃, the esterification reaction time was 3h, and the esterification reaction was carried out under nitrogen protection; the polycondensation reaction was specifically carried out as follows: after polycondensation at 240℃ and vacuum degree of 500Pa for 1h, polycondensation was carried out at 260℃ and vacuum degree of 40Pa for 2h.

[0046] S2. Modified PET chips are dried, then melt-spun, cooled and shaped, and stretched to obtain high-performance polyester with high dyeability. Specifically, the drying process is as follows: drying at 70℃ for 10 hours; melt spinning is carried out in a melt spinning machine at a spinning temperature of 280℃, a spinning speed of 1000m / min, and a spinneret orifice diameter of 0.25mm; the stretching ratio is 3, and the stretching temperature is 80℃.

[0047] The modified monomer is prepared by the following steps:

[0048] Polyethylene glycol, sodium isophthalate-5-sulfonate, and ethylene glycol were mixed and placed in a reaction vessel. Under nitrogen protection, the mixture was reacted at 160°C for 2 hours. Then, it was added to a 5% sodium hydroxide aqueous solution and stirred until homogeneous. Carboxymethyl-β-cyclodextrin and 1-carboxy-o-carborane were added, and the mixture was stirred at 100°C for 1 hour. After cooling to room temperature, the mixture was filtered to obtain the modified monomer. The mass ratio of polyethylene glycol, sodium isophthalate-5-sulfonate, ethylene glycol, sodium hydroxide aqueous solution, carboxymethyl-β-cyclodextrin, and 1-carboxy-o-carborane was 1:1:1.5:40:0.5:0.5.

[0049] The modified nanoparticles are prepared by the following steps:

[0050] A1. Nano-montmorillonite, glucose, and tannic acid were added to ethanol and stirred at 70°C for 30 min. After filtration, the mixture was dried in an oven at 70°C for 10 min, placed in a tube furnace, and a 30% potassium hydroxide solution was added. Nitrogen gas was introduced, and the mixture was carbonized at 750°C for 3 h. After cooling to room temperature, the mixture was removed, washed three times with deionized water, and dried in an oven at 70°C for 10 min to obtain nano-montmorillonite loaded with porous carbon. The ratio of nano-montmorillonite, glucose, tannic acid, ethanol, and potassium hydroxide solution was 2:1:0.3:80:4.

[0051] A2. Add porous carbon-loaded nano-montmorillonite to ethanol and deionized water, stir evenly, add KH570, stir and react at 70℃ for 1.5h, cool to room temperature, filter, wash 3 times with ethanol and 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain modified nanoparticles; the mass ratio of porous carbon-loaded nano-montmorillonite, ethanol, deionized water and KH570 is 2.5:80:30:1.

[0052] Example 2

[0053] A process for preparing high-level dyeing performance polyester suitable for conventional temperature dyeing includes the following steps:

[0054] S1. Terephthalic acid, ethylene glycol, modified monomers, and tetrabutyl titanate are mixed and subjected to esterification reaction. Triphenyl phosphate and modified nanoparticles are added and subjected to polycondensation reaction. After discharge, water cooling, and pelletizing, modified PET chips are obtained. The mass ratio of terephthalic acid, ethylene glycol, modified monomers, tetrabutyl titanate, triphenyl phosphate, and modified nanoparticles is 85:10:5:0.08:0.04:4.

[0055] The esterification reaction temperature was 230℃, the esterification reaction time was 3.5h, and the esterification reaction was carried out under nitrogen protection; the polycondensation reaction was specifically carried out as follows: after polycondensation at 245℃ and vacuum degree of 800Pa for 1.3h, polycondensation was carried out at 265℃ and vacuum degree of 45Pa for 2.5h.

[0056] S2. Modified PET chips are dried, then melt-spun, cooled and shaped, and stretched to obtain high-performance polyester with high dyeability. Specifically, the drying process is as follows: drying at 80℃ for 11 hours; melt spinning is carried out in a melt spinning machine at a spinning temperature of 288℃, a spinning speed of 1300m / min, and a spinneret orifice diameter of 0.28mm; the stretching ratio is 3.3, and the stretching temperature is 85℃.

[0057] The modified monomer is prepared by the following steps:

[0058] Polyethylene glycol, sodium isophthalate-5-sulfonate, and ethylene glycol were mixed and placed in a reaction vessel. Under nitrogen protection, the mixture was reacted at 170°C for 2.5 h. Then, it was added to a 5% sodium hydroxide aqueous solution and stirred until homogeneous. Carboxymethyl-β-cyclodextrin and 1-carboxy-o-carborane were added, and the mixture was stirred at 110°C for 1.3 h. After cooling to room temperature, the mixture was filtered to obtain the modified monomer. The mass ratio of polyethylene glycol, sodium isophthalate-5-sulfonate, ethylene glycol, sodium hydroxide aqueous solution, carboxymethyl-β-cyclodextrin, and 1-carboxy-o-carborane was 1.3:1.3:2:45:0.7:0.7.

[0059] The modified nanoparticles are prepared by the following steps:

[0060] A1. Nano-montmorillonite, glucose, and tannic acid were added to ethanol and stirred at 70°C for 30 min. After filtration, the mixture was dried in an oven at 70°C for 10 min, placed in a tube furnace, and a 30% potassium hydroxide solution was added. Nitrogen gas was introduced, and the mixture was carbonized at 800°C for 4 h. After cooling to room temperature, the mixture was removed, washed three times with deionized water, and dried in an oven at 70°C for 10 min to obtain nano-montmorillonite loaded with porous carbon. The ratio of nano-montmorillonite, glucose, tannic acid, ethanol, and potassium hydroxide solution was 2.5:1.3:0.4:90:5.

[0061] A2. Add porous carbon-loaded nano-montmorillonite to ethanol and deionized water, stir evenly, add KH570, stir and react at 70℃ for 1.5h, cool to room temperature, filter, wash 3 times with ethanol and 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain modified nanoparticles; the mass ratio of porous carbon-loaded nano-montmorillonite, ethanol, deionized water and KH570 is 3:85:33:1.1.

[0062] Example 3

[0063] A process for preparing high-level dyeing performance polyester suitable for conventional temperature dyeing includes the following steps:

[0064] S1. Terephthalic acid, ethylene glycol, modified monomers, and tetrabutyl titanate are mixed and subjected to esterification reaction. Triphenyl phosphate and modified nanoparticles are added and subjected to polycondensation reaction. After discharge, water cooling, and pelletizing, modified PET chips are obtained. The mass ratio of terephthalic acid, ethylene glycol, modified monomers, tetrabutyl titanate, triphenyl phosphate, and modified nanoparticles is 90:12:6:0.1:0.05:5.

[0065] The esterification reaction temperature was 240℃, the esterification reaction time was 4h, and the esterification reaction was carried out under nitrogen protection; the polycondensation reaction was specifically carried out as follows: after polycondensation at 250℃ and vacuum degree of 1000Pa for 1.5h, polycondensation was carried out at 270℃ and vacuum degree of 50Pa for 3h.

[0066] S2. Modified PET chips are dried, then melt-spun, cooled and shaped, and stretched to obtain high-performance polyester with high dyeability. Specifically, the drying process is as follows: drying at 90℃ for 12 hours; melt spinning is carried out in a melt spinning machine at a spinning temperature of 295℃, a spinning speed of 1500m / min, and a spinneret orifice diameter of 0.3mm; the stretching ratio is 3.5, and the stretching temperature is 90℃.

[0067] The modified monomer is prepared by the following steps:

[0068] Polyethylene glycol, sodium isophthalate-5-sulfonate, and ethylene glycol were mixed and placed in a reaction vessel. Under nitrogen protection, the mixture was reacted at 180°C for 3 hours. Then, it was added to a 5% sodium hydroxide aqueous solution and stirred until homogeneous. Carboxymethyl-β-cyclodextrin and 1-carboxy-o-carborane were added, and the mixture was stirred at 120°C for 1.5 hours. After cooling to room temperature, the mixture was filtered to obtain the modified monomer. The mass ratio of polyethylene glycol, sodium isophthalate-5-sulfonate, ethylene glycol, sodium hydroxide aqueous solution, carboxymethyl-β-cyclodextrin, and 1-carboxy-o-carborane was 1.5:1.5:2.5:50:1:1.

[0069] The modified nanoparticles are prepared by the following steps:

[0070] A1. Nano-montmorillonite, glucose, and tannic acid were added to ethanol and stirred at 70°C for 30 min. After filtration, the mixture was dried in an oven at 70°C for 10 min, placed in a tube furnace, and a 30% potassium hydroxide solution was added. Nitrogen gas was introduced, and the mixture was carbonized at 850°C for 5 h. After cooling to room temperature, the mixture was removed, washed three times with deionized water, and dried in an oven at 70°C for 10 min to obtain nano-montmorillonite loaded with porous carbon. The ratio of nano-montmorillonite, glucose, tannic acid, ethanol, and potassium hydroxide solution was 3:1.5:0.5:100:6.

[0071] A2. Add porous carbon-loaded nano-montmorillonite to ethanol and deionized water, stir evenly, add KH570, stir and react at 70℃ for 1.5h, cool to room temperature, filter, wash 3 times with ethanol and 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain modified nanoparticles; the mass ratio of porous carbon-loaded nano-montmorillonite, ethanol, deionized water and KH570 is 3.5:90:35:1.2.

[0072] Comparative Example 1

[0073] The only difference between this comparative example and Example 3 is the preparation of the modified monomer, as detailed below:

[0074] The modified monomer is prepared by the following steps:

[0075] Polyethylene glycol, sodium isophthalate-5-sulfonate, and ethylene glycol were mixed and placed in a reaction vessel. Under nitrogen protection, the mixture was reacted at 180°C for 3 hours. Then, it was added to a 5% sodium hydroxide aqueous solution and stirred until homogeneous. 1-Carboxy-o-carborane was added, and the mixture was stirred at 120°C for 1.5 hours. After cooling to room temperature, the mixture was filtered to obtain the modified monomer. The mass ratio of polyethylene glycol, sodium isophthalate-5-sulfonate, ethylene glycol, sodium hydroxide aqueous solution, and 1-carboxy-o-carborane was 1.5:1.5:2.5:50:2.

[0076] Comparative Example 2

[0077] The only difference between this comparative example and Example 3 is the preparation of the modified monomer, as detailed below:

[0078] The modified monomer is prepared by the following steps:

[0079] Polyethylene glycol, sodium isophthalate-5-sulfonate, and ethylene glycol were mixed and placed in a reaction vessel. Under nitrogen protection, the mixture was reacted at 180°C for 3 hours. Then, it was added to a 5% sodium hydroxide aqueous solution and stirred until homogeneous. Carboxymethyl-β-cyclodextrin was added, and the mixture was stirred at 120°C for 1.5 hours. After cooling to room temperature, the mixture was filtered to obtain the modified monomer. The mass ratio of polyethylene glycol, sodium isophthalate-5-sulfonate, ethylene glycol, sodium hydroxide aqueous solution, and carboxymethyl-β-cyclodextrin was 1.5:1.5:2.5:50:2.

[0080] Comparative Example 3

[0081] The only difference between this comparative example and Example 3 is the preparation of the modified nanoparticles, as detailed below:

[0082] The modified nanoparticles are prepared by the following steps:

[0083] Nano-montmorillonite was added to ethanol and deionized water and stirred until homogeneous. KH570 was then added, and the mixture was stirred at 70°C for 1.5 h. After cooling to room temperature, the mixture was filtered, washed three times with ethanol, and three times with deionized water. The mixture was then dried in a 70°C oven for 10 min to obtain modified nanoparticles. The mass ratio of nano-montmorillonite, ethanol, deionized water, and KH570 was 3.5:90:35:1.2.

[0084] Comparative Example 4

[0085] The only difference between this comparative example and Example 3 is the preparation of the modified nanoparticles, as detailed below:

[0086] The modified nanoparticles are prepared by the following steps:

[0087] Nano-montmorillonite, glucose, and tannic acid were added to ethanol and stirred at 70°C for 30 min. After filtration, the mixture was dried in an oven at 70°C for 10 min, placed in a tube furnace, and a 30% potassium hydroxide solution was added. Nitrogen gas was introduced, and the mixture was carbonized at 850°C for 5 h. After cooling to room temperature, the mixture was removed, washed three times with deionized water, and dried in an oven at 70°C for 10 min to obtain modified nanoparticles. The ratio of nano-montmorillonite, glucose, tannic acid, ethanol, and potassium hydroxide solution was 3:1.5:0.5:100:6.

[0088] The high-performance polyester fibers with high even dyeing properties prepared in Examples 1-3 and Comparative Examples 1-4 were tested for performance.

[0089] The amount of disperse dye Torras Blue is 3% owf, the amount of leveling agent (the leveling agent is fatty alcohol polyoxyethylene ether) is 0.2%, the amount of dispersant (the dispersant is selected from sodium dodecyl sulfate) is 0.2%, the liquor ratio is 1:30, the dyeing is carried out at room temperature, the temperature is raised to 90℃ at a rate of 1℃ / min, and the temperature is held for 60min. After that, the dyed polyester is taken out, washed with water 5 times, and dried to obtain the dyed polyester.

[0090] According to GB / T 6688-2008, the K / S value of dyed polyester is used to represent the apparent color depth (color gain) of polyester, reflecting the amount of dye fixed on polyester and the dyeing effect; according to GB / T3921-2008 "Textiles - Tests for color fastness to soaping", a wash fastness tester is used to determine the wash fastness of multi-colored fabrics.

[0091] The breaking strength of the high-performance polyester fiber prepared above was tested according to GB / T14344-2022 standard, with a clamping distance of 250 mm and a stretching speed of 200 mm / min; the breaking elongation of the high-performance polyester fiber prepared above was tested using a multifilament tensile tester, with a pre-tension of 3 cN, a stretching speed of 200 mm / min, and a clamping distance of 200 mm.

[0092] As shown in Table 1 below.

[0093] Table 1. Performance testing of high-uniformity dyeing high-performance polyester fibers prepared in Examples 1-3 and Comparative Examples 1-4

[0094]

[0095] As can be seen from the data in Table 1, the high-level dyeing performance polyester fibers prepared in Examples 1-3 exhibit high level dyeing properties when dyed at normal temperatures.

[0096] In Comparative Example 1, a modified monomer prepared by replacing carboxymethyl-β-cyclodextrin with 1-carboxy-o-carborane by mass was used to prepare high-performance polyester with high level dyeing properties. Its dyeing performance decreased at normal temperature, which proved that β-cyclodextrin was dispersed on the modified monomer molecular chain. Its internal cavity is hydrophobic and its external surface is hydrophilic. It can form inclusion complexes with disperse dyes through hydrophobic interactions, so that the disperse dyes are uniformly adsorbed on the polyester fibers.

[0097] In Comparative Example 2, a modified monomer prepared by replacing 1-carboxylated o-carborane with carboxymethyl-β-cyclodextrin by mass was used to prepare high-level dyeing performance polyester. Its dyeing performance decreased at normal temperature, which proved that 1-carboxylated o-carborane contains a stable cage-like structure and has high thermal stability. Therefore, grafting 1-carboxylated o-carborane onto the monomer molecular chain can improve the thermal stability of the monomer and avoid its poor heat resistance, easy degradation and breakage during melt spinning, which would affect the high level dyeing performance of polyester fiber at normal temperature.

[0098] In Comparative Example 3, the nano-montmorillonite loaded with porous carbon was replaced with modified nano-montmorillonite particles to prepare high-performance polyester with high level dyeing properties. The dyeing performance decreased at normal temperatures, which proved that the porous carbon layer synthesized on the surface of nano-montmorillonite has a uniform porous structure, increases the dye diffusion channels, and reduces the dye diffusion resistance. This allows the polyester fiber to have high level dyeing performance when dyed at normal temperatures. In addition, the double adsorption of nano-montmorillonite and porous carbon layer prevents the polyester fiber from fading and discoloration, resulting in high color fastness of the polyester fiber.

[0099] In Comparative Example 4, modified nanoparticles prepared from porous carbon-loaded montmorillonite without KH570 surface modification were used to prepare high-level dyeing polyester. The dyeing performance decreased at normal temperatures, demonstrating that the silane coupling agent grafted onto the surface of the porous carbon-loaded montmorillonite nanoparticles resulted in reactive double bonds. During the polycondensation process, tetrabutyl titanate acted as a catalyst, allowing these reactive double bonds to participate in the synthesis of PET chips, forming a cross-linked network structure within the PET chips. This enabled the modified nanoparticles to graft onto the PET chip molecular chains, improving their dispersion and interaction with the polyester fibers. Consequently, this enhanced the high-level dyeing performance of the polyester fibers at normal temperatures. Furthermore, the cross-linked network structure formed by the modified nanoparticles in the polyester fibers could absorb and reduce stress generated by external forces, inhibit crack propagation, and improve the mechanical properties of the polyester fibers.

[0100] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0101] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A preparation process for high-level dyeing performance polyester suitable for conventional temperature dyeing, characterized in that, Includes the following steps: S1. Terephthalic acid, ethylene glycol, modified monomers and catalyst are mixed and esterified. Stabilizers and modified nanoparticles are added and polycondensation is carried out. After discharge, water cooling and pelletizing, modified PET chips are obtained. S2. After drying, modified PET chips are melt-spun, cooled and shaped, and stretched to obtain high-performance polyester with high even dyeing properties. The modified monomer is obtained by reacting polyethylene glycol, sodium isophthalate-5-sulfonate, ethylene glycol, carboxymethyl-β-cyclodextrin and 1-carboxylated o-carborane. The modified nanoparticles are obtained by synthesizing a porous carbon layer on the surface of nano-montmorillonite and then modifying the surface with a silane coupling agent.

2. The preparation process of high-level dyeing performance polyester suitable for conventional temperature dyeing according to claim 1, characterized in that, The modified monomer is obtained by the following steps: Polyethylene glycol, sodium isophthalate-5-sulfonate, and ethylene glycol were mixed and placed in a reaction vessel. Under nitrogen protection, the mixture was reacted at 160-180℃ for 2-3 hours. Then, it was added to a 5% sodium hydroxide aqueous solution and stirred until homogeneous. Carboxymethyl-β-cyclodextrin and 1-carboxy-o-carborane were added, and the mixture was stirred at 100-120℃ for 1-1.5 hours. After cooling to room temperature, the mixture was filtered to obtain the modified monomer.

3. The preparation process of high-level dyeing performance polyester suitable for conventional temperature dyeing according to claim 2, characterized in that, The mass ratio of polyethylene glycol, sodium isophthalate-5-sulfonate, ethylene glycol, sodium hydroxide aqueous solution, carboxymethyl-β-cyclodextrin and 1-carboxy-o-carborane is (1-1.5):(1-1.5):(1.5-2.5):(40-50):(0.5-1):(0.5-1).

4. The preparation process of high-level dyeing performance polyester suitable for conventional temperature dyeing according to claim 1, characterized in that, The modified nanoparticles are specifically prepared by the following steps: A1. Add nano-montmorillonite, glucose and tannic acid to ethanol, stir, filter, dry, place in a tube furnace, add potassium hydroxide solution, purge with nitrogen, carbonize at 750-850℃ for 3-5h, cool to room temperature, remove, wash and dry to obtain nano-montmorillonite loaded with porous carbon. A2. Add porous carbon-loaded nano-montmorillonite to ethanol and deionized water, stir until homogeneous, add silane coupling agent, stir the reaction, cool to room temperature, filter, wash, and dry to obtain modified nanoparticles.

5. The preparation process of high-level dyeing performance polyester suitable for conventional temperature dyeing according to claim 4, characterized in that, In step A1, the ratio of the amount of nano-montmorillonite, glucose, tannic acid, ethanol and potassium hydroxide solution is (2-3):(1-1.5):(0.3-0.5):(80-100):(4-6).

6. The preparation process of high-level dyeing performance polyester suitable for conventional temperature dyeing according to claim 4, characterized in that, In step A2, the mass ratio of the nano-montmorillonite loaded with porous carbon, ethanol, deionized water and silane coupling agent is (3-4):(25-35):(8-12):(0.6-1).

7. The preparation process of high-level dyeing performance polyester suitable for conventional temperature dyeing according to claim 1, characterized in that, In step S1, the mass ratio of terephthalic acid, ethylene glycol, modified monomer, catalyst, stabilizer and modified nanoparticles is (80-90):(8-12):(4-6):(0.05-0.1):(0.03-0.05):(3-5); In step S1, the catalyst is tetrabutyl titanate and the stabilizer is triphenyl phosphate.

8. The preparation process of high-level dyeing performance polyester suitable for conventional temperature dyeing according to claim 1, characterized in that, In step S1, the esterification reaction temperature is 220-240℃, the esterification reaction time is 3-4h, and the esterification reaction is carried out under nitrogen protection. In step S1, the polycondensation reaction specifically involves polycondensation at a temperature of 240-250℃ and a vacuum degree of 500-1000Pa for 1-1.5 hours, followed by a polycondensation reaction at a temperature of 260-270℃ and a vacuum degree of 40-50Pa for 2-3 hours.

9. The preparation process of high-level dyeing performance polyester suitable for conventional temperature dyeing according to claim 1, characterized in that, In step S2, the melt spinning is carried out in a melt spinning machine, with a spinning temperature of 280-295℃, a spinning speed of 1000-1500m / min, and a spinneret orifice diameter of 0.25-0.3mm. In step S2, the stretching ratio is 3-3.5, and the stretching temperature is 80-90℃.

10. A high-performance polyester with high level dyeing properties obtained by a preparation process of high level dyeing properties suitable for conventional temperature dyeing as described in any one of claims 1-9.

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