A multifunctional MoS 2 Preparation method of modified PET sheath-core composite fiber

Abstract

The present invention relates to the technical field of PET sheath-core composite fiber preparation, and discloses a multifunctional MoS 2 The preparation method of modified PET sheath-core composite fiber comprises the following steps: (1) preparing modified MoS 2 Monolayer nanosheet; the modified MoS 2 The modifier used for the single-layer nanosheets is hexadecyltrimethylammonium bromide; (2) the modified MoS 2 The single-layer nanosheets were added into PET polyester raw material to obtain a mixed slurry, and then MoS was prepared by in-situ polymerization. 2 Modified PET slices; (3) MoS 2 The modified PET slices and PET slices are used as the raw materials of the skin layer and the core layer respectively, and the skin-core composite fiber is obtained by double-component composite spinning. 2 The dispersion of the core-skin composite fiber makes it have the multifunctional properties of polyester such as high elasticity, antibacterial, far-infrared and flame retardant properties, and the preparation process is simple and cost-saving.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of PET sheath-core composite fibers, and in particular to a preparation method of multifunctional MoS2 modified PET sheath-core composite fibers. Background Art

[0002] Polyester (PET) is the world's largest and most widely used synthetic fiber variety, accounting for more than 60% of the world's synthetic fiber production. PET has the advantages of high strength, excellent physical and mechanical properties, good stability, etc. It is a thermoplastic resin with excellent comprehensive performance and is widely used in various fields such as fibers, packaging, containers, plastics, etc. In order to give full play to the advantages of PET, it is of great significance to develop modified PET polyester fibers.

[0003] By regulating the higher-level structure of polymers, such as multi-phase and multi-component structures, the high value of products can be achieved without changing the existing polymerization process and monomer sources. Introducing nano-reinforcement phases during polymer production or processing can produce nano-composite materials with improved performance and special functions. For example, differentiated functional fibers with antibacterial, flame retardant, far infrared or photothermal conversion functions can be prepared, greatly increasing their added value.

[0004] The emergence and development of new nanomaterials and two-dimensional materials have provided new possibilities for achieving high performance and multifunctionality of bulk polymers. Two-dimensional materials represented by graphene and molybdenum disulfide (MoS2) are a type of ultra-thin nanomaterials with only a single layer or a few layers of atomic / molecular thickness, and the raw materials are cheap and easy to obtain. Compared with traditional nanomaterials, they have excellent comprehensive performance and have more outstanding mechanical, electrical, optical, thermal, barrier and other properties. At the same time, because the thickness of two-dimensional materials reaches the atomic or molecular level, they have extremely high area / volume ratio and aspect ratio. After being introduced into the polymer matrix, they can form molecular composite materials. Their reinforcement effect far exceeds that of traditional nanomaterials, and good reinforcement effects can be achieved under extremely low dosage conditions. Therefore, the use of two-dimensional materials as functional nanophases is expected to achieve high-value precision manufacturing of bulk polymers, representing the technological frontier of the development of advanced polymer materials and fiber products. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a method for preparing a multifunctional MoS2 modified PET sheath-core composite fiber, in which MoS2 single-layer nanosheets are compounded with PET by in-situ polymerization, and sheath-core composite spinning is performed to obtain a composite fiber with a sheath-core structure, which has the multifunctional properties of high strength, good elasticity, antibacterial, and excellent far-infrared effects.

[0006] The purpose of the present invention is achieved by the following technical scheme: The present invention provides a method for preparing a multifunctional MoS2 modified PET sheath-core composite fiber, comprising the following steps:

[0007] (1) preparing a modified MoS2 monolayer nanosheet; the modifier used in the modified MoS2 monolayer nanosheet is hexadecyltrimethylammonium bromide;

[0008] (2) adding the modified MoS2 single-layer nanosheets into PET polyester raw materials to obtain a mixed slurry, and then preparing MoS2 modified PET slices by in-situ polymerization;

[0009] (3) MoS2-modified PET chips and PET chips are used as the raw materials for the skin layer and the core layer, respectively, and skin-core composite fibers are obtained through two-component composite spinning.

[0010] The present invention realizes the uniform dispersion of MoS2 nanosheets in polyethylene terephthalate (PET) by adopting an in-situ polymerization method without changing the existing polymerization process, and obtains MoS2 modified PET slices. The MoS2 modified PET slices have good antibacterial, far-infrared, flame retardant and other properties, and the PET slices maintain high high elasticity, high flexibility, high oil absorption and high impact resistance. The MoS2 modified PET slices and the PET slices are used as two components through skin-core composite spinning to obtain a composite fiber with a skin-core structure. The polyester component as a core layer has the characteristics of high strength and good elasticity, and has good compatibility with the MoS2 modified PET slices. The MoS2 modified PET slice component as a skin layer makes the fiber have excellent antibacterial and far-infrared effects. The composite fiber has the performance advantages of the polyester component and the MoS2 component at the same time, and the preparation cost is low.

[0011] The performance of the MoS2-modified PET sheath-core composite fiber has exceeded that of most functional fiber products on the market. The study also found that the sheath-core composite fiber has certain UV shielding and flame retardant effects, is multifunctional and has excellent performance, and has good application prospects.

[0012] Preferably, in step (1), the method for preparing the modified MoS2 single-layer nanosheet comprises the following steps:

[0013] (a) dissolving hexadecyltrimethylammonium bromide in water to obtain a first solution, dissolving sodium molybdate and thiourea in water to obtain a second solution, and then dropping the second solution into the first solution with the assistance of ultrasound, and after the dropwise addition is completed, adjusting the pH to less than 1 to obtain a mixed solution;

[0014] (b) The mixed solution is heated to react, and after the reaction is completed, post-processing is performed to obtain modified MoS2 single-layer nanosheets.

[0015] Hexadecyltrimethylammonium bromide has good surface activity, stability, and good coordination with nonionic and zwitterionic surfactants. Hexadecyltrimethylammonium bromide is added to the preparation process of MoS2 for modification. Hexadecyltrimethylammonium bromide has good affinity between sodium molybdate and thiourea. While ultrasonic-assisted dripping, hexadecyltrimethylammonium bromide can be evenly dispersed among the raw materials for the preparation of MoS2, and the cationic groups can also be evenly distributed on the surface of molybdenum disulfide, which can help to form a single-layer nanosheet structure of MoS2, and it is not easy to cause agglomeration after the nanosheet is formed, so that the dispersion uniformity of MoS2 in polyethylene terephthalate can also be better, which can prevent the modified molybdenum disulfide from secondary agglomeration during polymerization and spinning.

[0016] The present invention adopts a spatial confinement method to prepare single-layer MoS2 nanosheets with high monolayer rate, adjustable size, good dispersion performance and hydroxyl functional groups, and realizes stable dispersion of MoS2 in a polymer matrix by regulating the polarity of the solvent through surface modification and chemical modification.

[0017] Preferably, the mass concentration of hexadecyltrimethylammonium bromide in the first solution is 0.1-0.5%; the mass concentrations of sodium molybdate and thiourea in the second solution are 0.4-0.6% and 0.80-0.9%, respectively; and the mass ratio of the first solution to the second solution is 1:1.

[0018] Preferably, the heating reaction is carried out at 160-200° C. for 22-26 hours.

[0019] Preferably, in step (2), the amount of MoS2 added to the mixed slurry is 0.1 to 1 wt%.

[0020] Preferably, in step (2), the modified MoS2 monolayer nanosheets are added to the PET polyester raw material, specifically: the modified MoS2 monolayer nanosheets are added to ethylene glycol to obtain a solution with a mass concentration of 2 to 3%, and then mixed with terephthalic acid, ethylene glycol and a catalyst to obtain a mixed slurry. The alcohol-acid ratio (ratio of terephthalic acid to ethylene glycol) in the mixed slurry is 1:1.1 to 1.3, and the amount of catalyst added is 230 to 250 ppm.

[0021] Preferably, in step (2), the in-situ polymerization is as follows: in a nitrogen atmosphere, the pressure is 0.3 to 0.35 MPa, the temperature is 235 to 255°C, the esterification reaction is carried out for 2 to 3 hours and the by-product water is continuously removed; after the esterification is completed, the pre-condensation reaction is carried out for 0.5 to 1 hour at a vacuum of -0.09 to -0.1 MPa and 260 to 270°C; and then the condensation reaction is carried out for 2 to 3 hours at a vacuum of less than 70 Pa and 273 to 278°C.

[0022] Preferably, in step (3), the mass of the skin layer accounts for 30-50% of the total mass of the skin layer and the core layer.

[0023] The skin-core fiber cross-section greatly increases the contact area between the two material components, allowing the blended fiber to have excellent antibacterial ability while having good mechanical properties. It can also reduce the proportion of modified MoS2 in the fiber, effectively reducing production costs.

[0024] Preferably, in step (3), the spinning box temperature of the composite spinning is 275-295°C.

[0025] If the box temperature is low, the spinning condition will be poor and the yarn will break easily; if the box temperature is high, the fiber strength will be low and the performance will be reduced.

[0026] Preferably, in step (3), the filaments obtained by the composite spinning are cooled, oiled, stretched and shaped, and wound to obtain a core-skin composite fiber; the cooling is carried out by side-blowing cooling, and the side-blowing wind speed is 0.7-1.0 m / s; during the stretching and shaping process, the temperature of the first hot roller is 70-90°C, the temperature of the second hot roller is 130-180°C, and the stretching ratio is 3.0-4.0.

[0027] When the temperature of the hot roller and the stretching ratio are controlled within the above range, the fiber can have better strength and appropriate elongation at break.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) Improve the dispersibility of MoS2 by modification and in-situ polymerization, and improve the uniformity of MoS2 distribution in the composite fiber, so as to obtain composite fibers with excellent performance, so that the fiber itself has good mechanical properties;

[0030] (2) MoS2-modified PET chips and PET chips are used as two components through sheath-core composite spinning to obtain a sheath-core structured composite fiber, which has the multifunctional properties of polyester such as high elasticity, high flexibility, high oil absorption, high impact resistance, antibacterial, far infrared, and flame retardant properties, and the preparation process is simple and cost-saving. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is described below with specific embodiments, but the protection scope of the present invention is not limited thereto:

[0032] Example 1

[0033] A method for preparing a multifunctional MoS2-modified PET sheath-core composite fiber comprises the following steps:

[0034] (1) Preparation of modified MoS2 monolayer nanosheets: Dissolve hexadecyltrimethylammonium bromide in deionized water at room temperature until it is completely dissolved to obtain a first solution (the mass concentration of hexadecyltrimethylammonium bromide is 0.3%); dissolve sodium molybdate and thiourea in water to obtain a second solution (the mass concentrations of sodium molybdate and thiourea are 0.5% and 0.85%, respectively); then add the second solution dropwise to the first solution at a mass ratio of 1:1, while performing ultrasonic assistance. After the addition is completed, adjust the pH of the solution to less than 1 with concentrated hydrochloric acid; then quickly transfer the mixed solution into a high-pressure reactor with a polytetrafluoroethylene liner, seal it, treat it at 180°C for 24 hours, and naturally cool it to room temperature; centrifuge it with deionized water and ethanol, respectively, and collect it to obtain modified MoS2 monolayer nanosheets; (2) Add ethanol to the modified MoS2 monolayer nanosheets In the diol, a modified MoS2 ethylene glycol solution (mass concentration is 2.5%) is obtained; terephthalic acid, ethylene glycol, catalyst (ethylene glycol antimony), and modified MoS2 ethylene glycol solution are mixed in a reaction vessel and then slurried, wherein the amount of MoS2 added to the mixed slurry is 0.5wt%, the alcohol-acid ratio is 1:1.2, and the amount of catalyst added is 240ppm; nitrogen is passed into the reaction vessel, the initial pressure is increased to 0.10Mpa, the temperature is raised to 245°C, and then the pressure is increased to 0.3Mpa, the esterification reaction is carried out for 2.5h, and the by-product water is continuously removed; after the esterification is completed, a pre-condensation reaction is carried out at -0.09Mpa vacuum and 270°C for 1h; then a condensation reaction is carried out at 50pa high vacuum and 275°C for 2.5h. After the reaction is completed, the melt is pressed out with nitrogen, water-cooled, and pelletized to obtain MoS2 modified PET chips;

[0035] (3) MoS2-modified PET chips and PET chips were dried and melted at 300°C to obtain MoS2-modified PET spinning melt and PET spinning melt; the two spinning melts were respectively introduced into a two-component composite spinning assembly through their respective corresponding pipes in a mass ratio of 50:50 for spinning, the spinning box temperature was 285°C, and filaments were ejected from the spinneret to form filaments; the filaments were cooled, oiled, stretched, shaped and wound (the temperature of the first hot roller was 75°C, the temperature of the second hot roller was 150°C; the stretching ratio was 3.5; the side blowing speed was 0.8 m / s) to obtain a composite fiber with a skin-core structure (specification 100 dtex / 36f), and the fiber cross section was concentric.

[0036] Example 2

[0037] The difference from Example 1 is that the amount of MoS2 added is 1.0wt%.

[0038] Example 3

[0039] The difference from Example 1 is that the amount of MoS2 added is 0.1wt%.

[0040] Example 4

[0041] A method for preparing a multifunctional MoS2-modified PET sheath-core composite fiber comprises the following steps:

[0042] (1) Preparation of modified MoS2 monolayer nanosheets: Dissolve hexadecyltrimethylammonium bromide in deionized water at room temperature until it is completely dissolved to obtain a first solution (the mass concentration of hexadecyltrimethylammonium bromide is 0.4%); dissolve sodium molybdate and thiourea in water to obtain a second solution (the mass concentrations of sodium molybdate and thiourea are 0.5% and 0.85%, respectively); then add the second solution dropwise to the first solution at a mass ratio of 1:1, while performing ultrasonic assistance. After the addition is completed, adjust the pH of the solution to less than 1 with concentrated hydrochloric acid; then quickly transfer the mixed solution into a high-pressure reactor with a polytetrafluoroethylene liner, seal it, treat it at 200°C for 24 hours, and naturally cool it to room temperature; centrifuge it with deionized water and ethanol, respectively, and collect it to obtain modified MoS2 monolayer nanosheets; (2) Add the modified MoS2 monolayer nanosheets In ethylene glycol, a modified MoS2 ethylene glycol solution (mass concentration is 2.2%) is obtained; terephthalic acid, ethylene glycol, catalyst (ethylene glycol antimony), and modified MoS2 ethylene glycol solution are mixed in a reaction vessel and then slurried, the amount of MoS2 added to the mixed slurry is 0.5wt%, the alcohol-acid ratio is 1:1.2, and the amount of catalyst added is 240ppm; nitrogen is passed into the reaction vessel, the initial pressure is increased to 0.08Mpa, the temperature is raised to 240°C, and then pressurized to 0.35Mpa, the esterification reaction is carried out for 2h, and the by-product water is continuously removed; after the esterification is completed, a pre-condensation reaction is carried out at -0.10Mpa vacuum and 265°C for 0.5h; then a condensation reaction is carried out at 50pa high vacuum and 275°C for 3h. After the reaction is completed, the melt is pressed out with nitrogen, water-cooled, and pelletized to obtain MoS2 modified PET chips;

[0043] (3) MoS2-modified PET chips and PET chips were dried and melted at 290°C to obtain MoS2-modified PET spinning melt and PET spinning melt; the two spinning melts were respectively introduced into a two-component composite spinning assembly through their respective corresponding pipelines in a mass ratio of 40:60 for spinning, the spinning box temperature was 285°C, and filaments were ejected from the spinneret to form filaments; the filaments were cooled, oiled, stretched, shaped and wound (the temperature of the first hot roller was 70°C, the temperature of the second hot roller was 180°C; the stretching ratio was 4.0; the side blowing speed was 0.9 m / s) to obtain a composite fiber with a skin-core structure (specification 100 dtex / 24f), and the fiber cross section was concentric.

[0044] Example 5

[0045] A method for preparing a multifunctional MoS2-modified PET sheath-core composite fiber comprises the following steps:

[0046] (1) Preparation of modified MoS2 monolayer nanosheets: Dissolve hexadecyltrimethylammonium bromide in deionized water at room temperature until it is completely dissolved to obtain a first solution (the mass concentration of hexadecyltrimethylammonium bromide is 0.5%); dissolve sodium molybdate and thiourea in water to obtain a second solution (the mass concentrations of sodium molybdate and thiourea are 0.6% and 0.90%, respectively); then add the second solution dropwise to the first solution at a mass ratio of 1:1, while performing ultrasonic assistance. After the addition is completed, adjust the pH of the solution to less than 1 with concentrated hydrochloric acid; then quickly transfer the mixed solution into a high-pressure reactor with a polytetrafluoroethylene liner, seal it, treat it at 180°C for 24 hours, and naturally cool it to room temperature; centrifuge it with deionized water and ethanol, respectively, and collect it to obtain modified MoS2 monolayer nanosheets; (2) Add the modified MoS2 monolayer nanosheets to ethanol In the diol, a modified MoS2 ethylene glycol solution (mass concentration is 2.2%) is obtained; terephthalic acid, ethylene glycol, catalyst (ethylene glycol antimony), and modified MoS2 ethylene glycol solution are mixed in a reaction vessel and then slurried, the amount of MoS2 added to the mixed slurry is 0.5wt%, the alcohol-acid ratio is 1:1.2, and the amount of catalyst added is 240ppm; nitrogen is passed into the reaction vessel, the initial pressure is increased to 0.10Mpa, the temperature is raised to 245°C, and then the pressure is increased to 0.3Mpa, the esterification reaction is carried out for 2.5h, and the by-product water is continuously removed; after the esterification is completed, a pre-condensation reaction is carried out at -0.09Mpa vacuum and 272°C for 1h; then a condensation reaction is carried out at 50pa high vacuum and 275°C for 2.5h. After the reaction is completed, the melt is pressed out with nitrogen, water-cooled, and pelletized to obtain MoS2 modified PET chips;

[0047] (3) MoS2-modified PET chips and PET chips were dried and melted at 300°C to obtain MoS2-modified PET spinning melt and PET spinning melt; the two spinning melts were respectively introduced into a two-component composite spinning assembly through their respective corresponding pipelines at a mass ratio of 30:70 for spinning, the spinning box temperature was 280°C, and filaments were ejected from the spinneret; the filaments were cooled, oiled, stretched, shaped and wound (the temperature of the first hot roller was 75°C, the temperature of the second hot roller was 150°C; the stretching ratio was 3.5; the side blowing speed was 0.8 m / s) to obtain a composite fiber with a skin-core structure (specification 100 dtex / 36f), and the fiber cross section was concentric.

[0048] Comparative Example 1

[0049] The difference from Example 1 is that the amount of MoS2 added is 2.0wt%.

[0050] Comparative Example 2

[0051] The difference from Example 1 is that the MoS2-modified PET chips are spun alone.

[0052] The following steps are involved:

[0053] (1) Preparation of modified MoS2 monolayer nanosheets: Dissolve hexadecyltrimethylammonium bromide in deionized water at room temperature until it is completely dissolved to obtain a first solution (the mass concentration of hexadecyltrimethylammonium bromide is 0.3%); dissolve sodium molybdate and thiourea in water to obtain a second solution (the mass concentrations of sodium molybdate and thiourea are 0.5% and 0.85%, respectively); then add the second solution dropwise to the first solution at a mass ratio of 1:1, while performing ultrasonic assistance. After the addition is completed, adjust the pH of the solution to less than 1 with concentrated hydrochloric acid; then quickly transfer the mixed solution into a high-pressure reactor with a polytetrafluoroethylene liner, seal it, treat it at 180°C for 24 hours, and naturally cool it to room temperature; centrifuge it with deionized water and ethanol, respectively, and collect it to obtain modified MoS2 monolayer nanosheets; (2) Add ethanol to the modified MoS2 monolayer nanosheets In the diol, a modified MoS2 ethylene glycol solution (mass concentration is 2.5%) is obtained; terephthalic acid, ethylene glycol, catalyst (ethylene glycol antimony), and modified MoS2 ethylene glycol solution are mixed in a reaction vessel and then slurried, wherein the amount of MoS2 added to the mixed slurry is 0.5wt%, the alcohol-acid ratio is 1:1.2, and the amount of catalyst added is 240ppm; nitrogen is passed into the reaction vessel, the initial pressure is increased to 0.10Mpa, the temperature is raised to 245°C, and then the pressure is increased to 0.3Mpa, the esterification reaction is carried out for 2.5h, and the by-product water is continuously removed; after the esterification is completed, a pre-condensation reaction is carried out at -0.09Mpa vacuum and 270°C for 1h; then a condensation reaction is carried out at 50pa high vacuum and 275°C for 2.5h. After the reaction is completed, the melt is pressed out with nitrogen, water-cooled, and pelletized to obtain MoS2 modified PET chips;

[0054] (3) The MoS2-modified PET chips are dried and melted at 300°C to obtain a MoS2-modified PET spinning melt, which enters a spinning assembly through a pipeline for spinning. The spinning box temperature is 285°C and the filaments are ejected from a spinneret to form filaments. The filaments are cooled, oiled, stretched, shaped and wound (the temperature of the first hot roller is 75°C, the temperature of the second hot roller is 150°C; the stretching ratio is 3.5; the side blowing speed is 0.8 m / s) to obtain MoS2-modified PET fibers (specification 100 dtex / 36f) with a circular cross-section.

[0055] Comparative Example 3

[0056] The difference from Example 1 is that during the composite spinning process, the spinning box temperature is 305°C, the first hot roller temperature is 105°C, and the second hot roller temperature is 185°C.

[0057] The following steps are involved:

[0058] (1) Preparation of modified MoS2 monolayer nanosheets: Dissolve hexadecyltrimethylammonium bromide in deionized water at room temperature until it is completely dissolved to obtain a first solution (the mass concentration of hexadecyltrimethylammonium bromide is 0.3%); dissolve sodium molybdate and thiourea in water to obtain a second solution (the mass concentrations of sodium molybdate and thiourea are 0.5% and 0.85%, respectively); then add the second solution dropwise to the first solution at a mass ratio of 1:1, while performing ultrasonic assistance. After the addition is completed, adjust the pH of the solution to less than 1 with concentrated hydrochloric acid; then quickly transfer the mixed solution into a high-pressure reactor with a polytetrafluoroethylene liner, seal it, treat it at 180°C for 24 hours, and naturally cool it to room temperature; centrifuge it with deionized water and ethanol, respectively, and collect it to obtain modified MoS2 monolayer nanosheets; (2) Add ethanol to the modified MoS2 monolayer nanosheets In the diol, a modified MoS2 ethylene glycol solution (mass concentration is 2.5%) is obtained; terephthalic acid, ethylene glycol, catalyst (ethylene glycol antimony), and modified MoS2 ethylene glycol solution are mixed in a reaction vessel and then slurried, wherein the amount of MoS2 added to the mixed slurry is 0.5wt%, the alcohol-acid ratio is 1:1.2, and the amount of catalyst added is 240ppm; nitrogen is passed into the reaction vessel, the initial pressure is increased to 0.10Mpa, the temperature is raised to 245°C, and then the pressure is increased to 0.3Mpa, the esterification reaction is carried out for 2.5h, and the by-product water is continuously removed; after the esterification is completed, a pre-condensation reaction is carried out at -0.09Mpa vacuum and 270°C for 1h; then a condensation reaction is carried out at 50pa high vacuum and 275°C for 2.5h. After the reaction is completed, the melt is pressed out with nitrogen, water-cooled, and pelletized to obtain MoS2 modified PET chips;

[0059] (3) MoS2-modified PET chips and PET chips were dried and melted at 300°C to obtain MoS2-modified PET spinning melt and PET spinning melt; the two spinning melts were respectively introduced into a two-component composite spinning assembly through their respective corresponding pipelines in a mass ratio of 50:50 for spinning, the spinning box temperature was 305°C, and filaments were ejected from the spinneret; the filaments were cooled, oiled, stretched, shaped and wound (the temperature of the first hot roller was 105°C, the temperature of the second hot roller was 185°C; the stretching ratio was 3.5; the side blowing speed was 0.8 m / s) to obtain a composite fiber with a skin-core structure (specification 100 dtex / 36f), and the fiber cross section was concentric.

[0060] Comparative Example 4

[0061] The difference from Example 1 is that MoS2 is not modified.

[0062] The following steps are involved:

[0063] (1) Preparation of MoS2 monolayer nanosheets: Sodium molybdate and thiourea were dissolved in water, and the pH of the solution was adjusted to less than 1 with concentrated hydrochloric acid to obtain a solution (the mass concentrations of sodium molybdate and thiourea were 0.5% and 0.85%, respectively); the solution was then quickly transferred into a high-pressure reactor with a polytetrafluoroethylene liner, sealed, treated at 180°C for 24 hours, and naturally cooled to room temperature; the solution was centrifuged and washed with deionized water and ethanol, respectively, and MoS2 monolayer nanosheets were collected;

[0064] (2) Adding MoS2 monolayer nanosheets to ethylene glycol to obtain an ethylene glycol solution of MoS2 (mass concentration is 2.5%); mixing terephthalic acid, ethylene glycol, catalyst (ethylene glycol antimony), and ethylene glycol solution of MoS2 in a reaction vessel and slurrying, wherein the amount of MoS2 added to the mixed slurry is 0.5wt%, the alcohol-acid ratio is 1:1.2, and the amount of catalyst added is 240ppm; nitrogen is passed into the reaction vessel, the initial pressure is increased to 0.10Mpa, the temperature is raised to 245°C, and then the pressure is increased to 0.3Mpa, the esterification reaction is carried out for 2.5h, and the by-product water is continuously removed; after the esterification is completed, a pre-condensation reaction is carried out at -0.09Mpa vacuum and 270°C for 1h; then a condensation reaction is carried out at 50pa high vacuum and 275°C for 2.5h. After the reaction is completed, the melt is pressed out with nitrogen, water-cooled, and pelletized to obtain MoS2 modified PET chips;

[0065] (3) MoS2-modified PET chips and PET chips were dried and melted at 300°C to obtain MoS2-modified PET spinning melt and PET spinning melt; the two spinning melts were respectively introduced into a two-component composite spinning assembly through their respective corresponding pipes in a mass ratio of 50:50 for spinning, the spinning box temperature was 285°C, and filaments were ejected from the spinneret to form filaments; the filaments were cooled, oiled, stretched, shaped and wound (the temperature of the first hot roller was 75°C, the temperature of the second hot roller was 150°C; the stretching ratio was 3.5; the side blowing speed was 0.8 m / s) to obtain a composite fiber with a skin-core structure (specification 100 dtex / 36f), and the fiber cross section was concentric.

[0066] Comparative Example 5

[0067] The difference from Example 1 is that the modifier used to modify MoS2 is stearic acid triethanolamine salt.

[0068] The following steps are involved:

[0069] (1) Preparation of modified MoS2 monolayer nanosheets: Dissolve stearic acid triethanolamine salt in deionized water at room temperature until completely dissolved to obtain a first solution (the mass concentration of stearic acid triethanolamine salt is 0.3%); dissolve sodium molybdate and thiourea in water to obtain a second solution (the mass concentrations of sodium molybdate and thiourea are 0.5% and 0.85%, respectively); then add the second solution dropwise to the first solution at a mass ratio of 1:1, while performing ultrasonic assistance. After the addition is completed, adjust the pH of the solution to less than 1 with concentrated hydrochloric acid; then quickly transfer the mixed solution into a high-pressure reactor with a polytetrafluoroethylene liner, seal it, treat it at 180°C for 24 hours, and naturally cool it to room temperature; centrifuge and wash it with deionized water and ethanol respectively, and collect the modified MoS2 monolayer nanosheets;

[0070] (2) Adding the modified MoS2 monolayer nanosheets to ethylene glycol to obtain a modified MoS2 ethylene glycol solution (mass concentration is 2.5%); mixing terephthalic acid, ethylene glycol, catalyst (ethylene glycol antimony), and the modified MoS2 ethylene glycol solution in a reaction vessel and slurrying, wherein the amount of MoS2 added to the mixed slurry is 0.5wt%, the alcohol-acid ratio is 1:1.2, and the amount of catalyst added is 240ppm; nitrogen is passed into the reaction vessel, the initial pressure is increased to 0.10Mpa, the temperature is raised to 245°C, and then the pressure is increased to 0.3Mpa, the esterification reaction is carried out for 2.5h, and the by-product water is continuously removed; after the esterification is completed, a pre-condensation reaction is carried out at -0.09Mpa vacuum and 270°C for 1h; then a condensation reaction is carried out at 50pa high vacuum and 275°C for 2.5h. After the reaction is completed, the melt is pressed out with nitrogen, water-cooled, and pelletized to obtain MoS2 modified PET chips;

[0071] (3) MoS2-modified PET chips and PET chips were dried and melted at 300°C to obtain MoS2-modified PET spinning melt and PET spinning melt; the two spinning melts were respectively introduced into a two-component composite spinning assembly through their respective corresponding pipes in a mass ratio of 50:50 for spinning, the spinning box temperature was 285°C, and filaments were ejected from the spinneret to form filaments; the filaments were cooled, oiled, stretched, shaped and wound (the temperature of the first hot roller was 75°C, the temperature of the second hot roller was 150°C; the stretching ratio was 3.5; the side blowing speed was 0.8 m / s) to obtain a composite fiber with a skin-core structure (specification 100 dtex / 36f), and the fiber cross section was concentric.

[0072] The performance of the fibers prepared in the above examples and comparative examples was evaluated, and the specific results are shown in Table 1.

[0073] Strength test: in accordance with GB / T-14337 Filament tensile properties test method standard;

[0074] Water absorption test: in accordance with GB / T12703.4-2010 standard;

[0075] Antibacterial property test: According to the standards of "FZ / T 73023-2006" and "GB / T 20944-2007", the antibacterial rates of Escherichia coli, Staphylococcus aureus and Candida albicans obtained in the embodiment of the present invention are ≥90%, which can be considered to have excellent antibacterial properties and be a superior product;

[0076] Far infrared property test: According to the standard of GB / T 30127-2013 Testing and evaluation of far infrared properties of textiles, the far infrared emissivity of the fabric obtained by the fiber prepared in the embodiment of the present invention is ≥0.88, and the far infrared radiation temperature rise is ≥1.4, and the far infrared performance is qualified.

[0077] Table 1

[0078]

[0079] As shown in Table 1, the core-skin composite fiber of the present invention has the characteristics of high strength and excellent functional effects. The MoS2 component is evenly dispersed without agglomeration. The fiber also has good antibacterial and far-infrared properties, and is a multifunctional high-value-added fiber.

[0080] Comparative Example 1 shows that the proportion of MoS2 added during polymerization is too high, which results in the inability to fully disperse MoS2 evenly and partial agglomeration, which is not conducive to its subsequent processing and reduces the mechanical properties of the fiber.

[0081] Comparative Example 2 shows that when MoS2-modified PET chips are single-spun, the obtained fiber has good antibacterial properties, but its strength is significantly reduced and the cost is relatively high, which cannot be compared with the fiber obtained in Example 1.

[0082] Comparative Example 3 shows that the spinning temperature of the obtained fiber is too high, resulting in partial degradation, and the obtained fiber cannot have strength. Moreover, since its winding temperature is too high, the obtained fiber is poorly formed and cannot meet the subsequent processing steps, and the obtained fiber has poor performance.

[0083] Comparative Example 4 shows that MoS2 was not surface-modified and chemically modified. Although the obtained fiber had antibacterial properties, its mechanical properties and antibacterial properties were reduced. This shows that surface-modification and chemical modification of MoS2 can better disperse it evenly, prevent agglomeration, and make the fiber have excellent properties.

[0084] Comparative Example 5 shows that the hexadecyltrimethylammonium bromide of the present invention has better modification effect as a modifier, while other cationic surfactants cannot achieve the same effect. The main reason may be that the affinity and dispersibility of other cationic surfactants in the MoS2 preparation raw materials are limited, and after the MoS2 nanosheets are generated, they cannot better promote the formation of a single-layer structure, which will lead to agglomeration in the subsequent polymerization and spinning process, and the spinning effect will be poor.

[0085] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the specification of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing a multifunctional MoS2-modified PET sheath-core composite fiber, characterized in that: The steps include: (1) Preparation of modified MoS2 monolayer nanosheets; (a) dissolving hexadecyltrimethylammonium bromide in water to obtain a first solution, dissolving sodium molybdate and thiourea in water to obtain a second solution, and then dropping the second solution into the first solution with the assistance of ultrasonic wave, and after the dropping is completed, adjusting the pH to less than 1 to obtain a mixed solution; (b) heating the mixed solution for reaction, and after the reaction is completed, performing post-treatment to obtain a modified MoS2 single-layer nanosheet; (2) adding the modified MoS2 single-layer nanosheets into PET polyester raw materials to obtain a mixed slurry, and then preparing MoS2 modified PET chips by in-situ polymerization; (3) MoS2-modified PET chips and PET chips were used as the raw materials for the skin layer and the core layer, respectively, and skin-core composite fibers were obtained through two-component composite spinning.

2. The method for preparing the multifunctional MoS2-modified PET core-skin composite fiber according to claim 1, characterized in that: The mass concentration of hexadecyltrimethylammonium bromide in the first solution is 0.1-0.5%; the mass concentrations of sodium molybdate and thiourea in the second solution are 0.4-0.6% and 0.8-0.9%, respectively; and the mass ratio of the first solution to the second solution is 1:

1.

3. The method for preparing the multifunctional MoS2-modified PET sheath-core composite fiber according to claim 1 or 2, characterized in that: The heating reaction is carried out at 160-200° C. for 22-26 hours.

4. The method for preparing the multifunctional MoS2-modified PET core-skin composite fiber according to claim 1, characterized in that: In step (2), the amount of MoS2 added to the mixed slurry is 0.1~1wt%.

5. The method for preparing the multifunctional MoS2-modified PET sheath-core composite fiber according to claim 1, characterized in that: In step (2), the modified MoS2 single-layer nanosheets are added to the PET polyester raw material, specifically: the modified MoS2 single-layer nanosheets are added to ethylene glycol to obtain a solution with a mass concentration of 2-3%, and then mixed with terephthalic acid, ethylene glycol and a catalyst to obtain a mixed slurry.

6. The method for preparing the multifunctional MoS2-modified PET sheath-core composite fiber according to claim 1, characterized in that: In step (2), the in-situ polymerization is as follows: in a nitrogen atmosphere, the pressure is 0.3~0.35Mpa, the temperature is 235~255°C, the esterification reaction is carried out for 2~3h and the by-product water is continuously removed; after the esterification is completed, the pre-polycondensation reaction is carried out for 0.5~1h in a vacuum of -0.09~-0.1Mpa and 260~270°C; and then the polycondensation reaction is carried out for 2~3h in a vacuum of less than 70Pa and 273~278°C.

7. The method for preparing the multifunctional MoS2-modified PET sheath-core composite fiber according to claim 1, characterized in that: In step (3), the mass of the skin layer accounts for 30-50% of the total mass of the skin layer and the core layer.

8. The method for preparing the multifunctional MoS2-modified PET core-skin composite fiber as claimed in claim 7, characterized in that: In step (3), the spinning box temperature of the composite spinning is 275-295°C.

9. The method for preparing the multifunctional MoS2-modified PET core-skin composite fiber according to claim 7, characterized in that: In step (3), the filaments obtained by the composite spinning are cooled, oiled, stretched and shaped, and wound to obtain a core-skin composite fiber; the cooling is carried out by side-blowing cooling, and the side-blowing wind speed is 0.7-1.0 m / s; during the stretching and shaping process, the temperature of the first hot roller is 70-90°C, the temperature of the second hot roller is 130-180°C, and the stretching ratio is 3.0-4.0.

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