Preparation method of tungsten sulfide modified PTT antibacterial elastic composite fiber

Abstract

The invention relates to the field of chemical fibers, and discloses a tungsten sulfide modified PTT antibacterial elastic composite fiber preparation method, which comprises: 1) adding a hexadecyl trimethyl ammonium bromide modified tungsten sulfide single-layer nanosheet into a synthesis raw material of PTT polyester to obtain a mixed slurry, and carrying out in-situ polymerization to prepare a tungsten sulfide modified PTT slice; and 2) taking the tungsten sulfide modified PTT slices and the PET slices as raw materials, and carrying out double-component composite spinning to prepare the tungsten sulfide modified PTT antibacterial elastic composite fiber. The tungsten sulfide single-layer nanosheets are compounded with PTT in an in-situ polymerization mode, the tungsten sulfide single-layer nanosheets are good in dispersity and compatibility in PTT, and then the tungsten sulfide single-layer nanosheets and PET slices are subjected to parallel composite spinning, so that the prepared composite fiber has an excellent antibacterial effect, and meanwhile, the composite fiber is high in strength and good in elasticity.

Description

Technical Field

[0001] The present invention relates to the field of chemical fibers, and in particular to a method for preparing tungsten sulfide-modified PTT antibacterial elastic composite fiber. Background Art

[0002] Polytrimethylene terephthalate (PTT) is a novel organic high-molecular-weight aromatic polyester product belonging to the same polymer family as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT). It is derived from purified terephthalic acid (PTA) and 1,3-propylene glycol (PDO) via esterification and polycondensation. PTT fibers have excellent elasticity, combining the softness of nylon, the bulk of acrylic, and the stain resistance of polyester, and have therefore attracted widespread attention. To further increase their market value and expand their application scenarios, the development of functional PTT fibers and fabrics has become a research hotspot in recent years.

[0003] In daily life, textiles often become breeding grounds for harmful microorganisms. By giving fibers antimicrobial properties, harmful microorganisms can be killed and their proliferation inhibited, thereby achieving a hygienic and health-care effect, and largely avoiding the risk of disease caused by bacterial infection. Therefore, the development of PTT fiber's antimicrobial properties is of great practical significance for the application of PTT fiber fabrics.

[0004] Currently, Patent No. CN111074373A discloses a flame-retardant and antibacterial PTT fiber material and its preparation method. By combining a flame retardant and a nanocomposite material, a PTT fiber nanocomposite with excellent flame retardancy, smoke suppression, and antibacterial properties is prepared. Patent No. CN110904679A discloses a method for preparing bio-based PTT antibacterial fabric. Bio-based PTT fibers that have undergone an alkali reduction treatment and finishing with a finishing solution are then in-situ finished in a metal salt solution to produce PTT fibers with antibacterial properties against specific bacterial species.

[0005] However, the preparation method of the modifier in the aforementioned patent is too complicated, difficult to industrialize, and has high production costs. Although the antibacterial PTT fiber obtained based on this method has antibacterial properties, the preparation process is complicated and lengthy. In addition, the antibacterial effect obtained by this post-treatment cannot be maintained for a long time, and the antibacterial performance is poor. Summary of the Invention

[0006] In order to overcome the problems of poor industrial operability and unsatisfactory antibacterial effect, the present invention provides a method for preparing tungsten sulfide-modified PTT antibacterial elastic composite fibers. In the present invention, tungsten sulfide monolayer nanosheets are composited with PTT by in-situ polymerization. The tungsten sulfide monolayer nanosheets have good dispersibility and compatibility in PTT. The tungsten sulfide monolayer nanosheets are then composited with PET slices in parallel by spinning. The resulting composite fibers have excellent antibacterial effect, high strength and good elasticity.

[0007] The specific technical solution of the present invention is: a method for preparing tungsten sulfide modified PTT antibacterial elastic composite fiber, which comprises the following steps: 1) Hexadecyltrimethylammonium bromide-modified tungsten sulfide monolayer nanosheets are added to the synthetic raw materials of PTT polyester to obtain a mixed slurry, and tungsten sulfide-modified PTT slices are prepared by in-situ polymerization.

[0008] 2) Tungsten sulfide modified PTT chips and PET chips were used as raw materials and two-component composite spinning was performed to prepare tungsten sulfide modified PTT antibacterial elastic composite fibers.

[0009] The present invention achieves uniform dispersion of tungsten sulfide monolayer nanosheets in PTT through in-situ polymerization, without changing the existing PTT polymerization process, thereby producing tungsten sulfide-modified PTT slices. These slices exhibit excellent antibacterial properties while maintaining high elasticity and flexibility. By utilizing the elasticity of the tungsten sulfide-modified PTT slices and the viscosity difference between them and low-viscosity PET slices for parallel composite spinning, the resulting tungsten sulfide-modified PTT antibacterial elastic composite fibers exhibit excellent antibacterial properties, a comfortable feel, high elasticity, and low production cost, promising promising applications.

[0010] The present invention selects hexadecyltrimethylammonium bromide as a modifier for the tungsten sulfide monolayer nanosheets. Hexadecyltrimethylammonium bromide has a better affinity for sodium tungstate and thiourea. Ultrasonic-assisted dropwise addition allows it to be evenly dispersed among the raw materials for preparing tungsten sulfide. The cationic groups are also evenly distributed on the surface of the tungsten sulfide, thereby facilitating the formation of a monolayer tungsten sulfide nanosheet structure. After the nanosheets are formed, agglomeration is not easily caused, resulting in better dispersion uniformity of the tungsten sulfide in PTT and preventing secondary agglomeration of the modified tungsten sulfide during polymerization and spinning. Using other conventional cationic surfactants cannot achieve the same effect, mainly because their affinity and dispersibility in the tungsten sulfide preparation raw materials are limited, and after the tungsten sulfide nanosheets are generated, they cannot better promote the formation of a monolayer structure. This can lead to agglomeration during the subsequent polymerization and spinning processes, resulting in poor spinning results.

[0011] Preferably, in step 1), the content of the cetyltrimethylammonium bromide modified tungsten sulfide monolayer nanosheets in the mixed slurry is 0.1-1 wt %.

[0012] The content of modified tungsten sulfide single-layer nanosheets should not be too high, otherwise it is easy to cause partial agglomeration due to inability to fully disperse evenly, which is not conducive to its subsequent processing and will eventually lead to a decrease in various mechanical properties of the fiber.

[0013] Preferably, in step 1), the method for preparing the hexadecyltrimethylammonium bromide modified tungsten sulfide monolayer nanosheets comprises: a) an aqueous solution containing hexadecyltrimethylammonium bromide is used as a first solution, and an aqueous solution containing sodium tungstate and thiourea is used as a second solution; the second solution is added dropwise to the first solution under ultrasonic assistance; and the pH is adjusted to less than 1 after the addition to obtain a mixed solution.

[0014] b) heating the mixed solution for reaction, and performing post-treatment to obtain hexadecyltrimethylammonium bromide-modified tungsten sulfide monolayer nanosheets.

[0015] The present invention uses a spatial confinement method to prepare modified tungsten sulfide monolayer nanosheets with high monolayer rate, adjustable size, good dispersion performance and containing cationic functional groups. Through surface modification and chemical modification, the polarity of the solvent is regulated to achieve stable dispersion of tungsten sulfide in a polymer matrix.

[0016] Preferably, in step a), the concentration of hexadecyltrimethylammonium bromide in the first solution is 0.1-0.5 wt%; the concentrations of sodium tungstate and thiourea in the second solution are 0.4-0.6 wt% and 0.8-0.9 wt%, respectively; and the mass ratio of the first solution to the second solution is (0.8-1.2):1.

[0017] Preferably, in step b), the heating reaction is carried out at 160-200° C. for 22-26 hours.

[0018] Preferably, in step 1), the preparation of the mixed slurry comprises: adding hexadecyltrimethylammonium bromide-modified tungsten sulfide monolayer nanosheets to propylene glycol to obtain a solution with a concentration of 2 to 3 wt%, and then mixing with terephthalic acid (PTA), 1.3-propylene glycol (PDO) and a catalyst to obtain a mixed slurry; the molar ratio of alcohol to acid (the ratio of terephthalic acid to propylene glycol) in the mixed slurry is 1:1.2 to 2.0, and the content of the catalyst is 90 to 100 ppm.

[0019] Preferably, in step 1), the in-situ polymerization comprises: an esterification reaction for 2 to 3 hours under an inert atmosphere at a pressure of 0.3 to 0.35 MPa and a temperature of 235 to 255° C., and continuous removal of by-product water; after the esterification is completed, a pre-polycondensation reaction is carried out at a vacuum of -0.09 to -0.1 MPa and a temperature of 260 to 270° C. for 0.5 to 1 hour; and then a polycondensation reaction is carried out at a vacuum of less than 70 Pa and a temperature of 260 to 270° C. for 2 to 3 hours.

[0020] Preferably, in step 2), the spinning box temperature of the two-component composite spinning is 265-275°C.

[0021] The present invention has found that if the spinning box temperature is too low, the spinning condition is poor and the yarn is easily broken; if the box temperature is too high, the fiber strength is low and the performance is reduced. The effect is best within the above range.

[0022] Preferably, in step 2), the filaments obtained by the two-component composite spinning are cooled, oiled, stretched, shaped and wound to obtain composite fibers.

[0023] Further preferably, in step 2), the cooling is performed by side-blowing cooling, and the side-blowing 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.

[0024] By controlling the temperature of the hot roller and the stretching ratio within the above ranges, the fiber can have better strength, elasticity and appropriate elongation at break.

[0025] Preferably, in step 2), the viscosity of the PET chips is 0.4-0.5 dl / g.

[0026] By utilizing the elasticity of tungsten sulfide-modified PTT chips and the viscosity difference with low-viscosity PET chips for parallel composite spinning, the resulting tungsten sulfide-modified PTT antibacterial elastic composite fiber exhibits excellent antibacterial properties, a comfortable feel, and high elasticity. If the viscosity of the PET chips is low, the fiber's physical properties will be poor, affecting subsequent processing and use. If the chips have high viscosity, the fiber's elasticity and recovery rate will be poor, losing the performance advantages of parallel composite spinning.

[0027] Preferably, in step 2), the mass ratio of the PTT slice to the PET slice is in the range of 40:60 to 60:40.

[0028] Compared with the prior art, the present invention has the following beneficial effects: (1) In the present invention, tungsten sulfide monolayer nanosheets are composited with PTT by in-situ polymerization. The tungsten sulfide monolayer nanosheets have good dispersibility and compatibility in PTT. The tungsten sulfide monolayer nanosheets are then composited with PET slices in parallel by spinning. The resulting composite fiber has excellent antibacterial effect, high strength and good elasticity.

[0029] (2) The present invention selects hexadecyltrimethylammonium bromide as a modifier for tungsten sulfide monolayer nanosheets. Hexadecyltrimethylammonium bromide has better affinity between sodium tungstate and thiourea. Ultrasonic-assisted dropwise addition allows it to be evenly dispersed among the raw materials for preparing tungsten sulfide. The cationic groups can also be evenly distributed on the surface of tungsten sulfide, thereby contributing to the formation of a monolayer tungsten sulfide nanosheet structure. After the nanosheets are formed, it is not easy to cause agglomeration, so that the dispersion uniformity of tungsten sulfide in PTT can also be better, which can prevent the modified tungsten sulfide from secondary agglomeration during polymerization and spinning.

[0030] (3) The present invention uses tungsten sulfide to modify the elasticity of PTT chips and PET chips as two components for parallel composite spinning, thereby producing a dumbbell-shaped composite fiber with high elasticity, high flexibility, high strength and excellent antibacterial properties, and the preparation process is simple and cost-effective. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to the embodiments.

[0032] Overall embodiment The specific technical solution of the present invention is: a method for preparing tungsten sulfide modified PTT antibacterial elastic composite fiber, which comprises the following steps: 1) An aqueous solution containing hexadecyltrimethylammonium bromide is used as a first solution, and an aqueous solution containing sodium tungstate and thiourea is used as a second solution. The second solution is added dropwise to the first solution under ultrasonic assistance. After the addition, the pH is adjusted to <1 to obtain a mixed solution. The mixed solution is heated for reaction and post-treated to obtain hexadecyltrimethylammonium bromide-modified tungsten sulfide monolayer nanosheets.

[0033] Preferably, the concentration of hexadecyltrimethylammonium bromide in the first solution is 0.1-0.5 wt %; the concentrations of sodium tungstate and thiourea in the second solution are 0.4-0.6 wt % and 0.8-0.9 wt %, respectively; and the mass ratio of the first solution to the second solution is (0.8-1.2):1. Preferably, the heating reaction is carried out at 160-200° C. for 22-26 hours.

[0034] 2) adding hexadecyltrimethylammonium bromide modified tungsten sulfide monolayer nanosheets to the synthetic raw materials of PTT polyester to obtain a mixed slurry, and preparing tungsten sulfide modified PTT slices by in situ polymerization.

[0035] Preferably, the content of the cetyltrimethylammonium bromide modified tungsten sulfide monolayer nanosheets in the mixed slurry is 0.1-1 wt %.

[0036] Preferably, the preparation of the mixed slurry includes: adding hexadecyltrimethylammonium bromide-modified tungsten sulfide monolayer nanosheets to propylene glycol to obtain a solution with a concentration of 2 to 3 wt%, and then mixing with terephthalic acid (PTA), 1.3-propylene glycol (PDO) and a catalyst to obtain a mixed slurry; the molar ratio of alcohol to acid (the ratio of terephthalic acid to propylene glycol) in the mixed slurry is 1:1.2 to 2.0, and the content of the catalyst is 90 to 100 ppm.

[0037] Preferably, the in-situ polymerization includes: an esterification reaction for 2 to 3 hours under an inert atmosphere at a pressure of 0.3 to 0.35 MPa and a temperature of 235 to 255° C., and continuous removal of by-product water; after the esterification is completed, a pre-condensation reaction is carried out at a vacuum of -0.09 to -0.1 MPa and a temperature of 260 to 270° C. for 0.5 to 1 hour; and then a condensation reaction is carried out at a vacuum of less than 70 Pa and a temperature of 260 to 270° C. for 2 to 3 hours.

[0038] 3) Tungsten sulfide modified PTT chips and PET chips were used as raw materials and two-component composite spinning was performed to prepare tungsten sulfide modified PTT antibacterial elastic composite fibers.

[0039] Preferably, the spinning box temperature of the two-component composite spinning is 265-275°C.

[0040] Preferably, the filaments obtained by the two-component composite spinning are cooled, oiled, stretched, shaped and wound to obtain composite fibers.

[0041] Further preferably, the cooling adopts side-blowing cooling with a side-blowing speed of 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.

[0042] Preferably, the viscosity of the PET chips is 0.4-0.5 dl / g.

[0043] Preferably, the mass ratio of the PTT slice to the PET slice ranges from 40:60 to 60:40.

[0044] Specific Examples and Comparative Examples Example 1 (1) Preparation of modified tungsten sulfide monolayer nanosheets: dissolve hexadecyltrimethylammonium bromide in deionized water at room temperature until completely dissolved to obtain a first solution (the mass concentration of hexadecyltrimethylammonium bromide is 0.3%); dissolve sodium tungstate and thiourea in water to obtain a second solution (the mass concentrations of sodium tungstate 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 tungsten sulfide monolayer nanosheets; (2) Add the modified tungsten sulfide monolayer nanosheets to PDO, A PDO solution of modified tungsten sulfide (mass concentration is 2.5%) is obtained; terephthalic acid, PDO, a catalyst (tetrabutyl titanate), and a propylene glycol solution of modified tungsten sulfide are mixed in a reaction vessel and then slurried, wherein the amount of modified tungsten sulfide monolayer nanosheets added to the mixed slurry is 0.5wt%, the alcohol-acid ratio is 1:1.5, and the amount of catalyst added is 100ppm; nitrogen is introduced 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, and the esterification reaction is carried out for 2.5h, and the by-product water is continuously removed; after the esterification is completed, a pre-polycondensation reaction is carried out at -0.09Mpa vacuum and 260°C for 1h; then a polycondensation reaction is carried out at 50Pa high vacuum and 270°C for 2.5h. After the reaction is completed, the melt is pressed out with nitrogen, water-cooled, and pelletized to obtain tungsten sulfide modified PTT chips; (3) Tungsten sulfide modified PTT chips and PET chips with a viscosity of 0.47 dl / g were dried separately and melted at 260°C to obtain tungsten sulfide modified PTT spinning melt and PET spinning melt; the two spinning melts were respectively fed 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 270°C, and the fibers were ejected from the spinneret to form filaments; the filaments were cooled, oiled, stretched and shaped, and wound (the first hot roller temperature was 75°C, the second hot roller temperature was 150°C; the stretching ratio was 3.5; the side blowing speed was 0.8 m / s) to obtain a parallel structure composite fiber (specification 100 dtex / 36f) with a dumbbell-shaped fiber cross section.

[0045] Example 2 The difference from Example 1 is that in step (2), the amount of modified tungsten sulfide monolayer nanosheets added to the mixed slurry is 1.0 wt%.

[0046] Example 3 The difference from Example 1 is that in step (2), the amount of modified tungsten sulfide monolayer nanosheets added to the mixed slurry is 0.1 wt %.

[0047] Example 4 (1) Preparation of modified tungsten sulfide monolayer nanosheets: dissolve hexadecyltrimethylammonium bromide in deionized water at room temperature until completely dissolved to obtain a first solution (the mass concentration of hexadecyltrimethylammonium bromide is 0.3%); dissolve sodium tungstate and thiourea in water to obtain a second solution (the mass concentrations of sodium tungstate 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 tungsten sulfide monolayer nanosheets; (2) Add the modified tungsten sulfide monolayer nanosheets to PDO, A PDO solution of modified tungsten sulfide (mass concentration is 2.5%) is obtained; terephthalic acid, PDO, a catalyst (tetrabutyl titanate), and a propylene glycol solution of modified tungsten sulfide are mixed in a reaction vessel and then slurried, wherein the amount of modified tungsten sulfide single-layer nanosheets added to the mixed slurry is 0.5wt%, the alcohol-acid ratio is 1:1.5, and the amount of catalyst added is 100ppm; nitrogen is introduced 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, and 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 260°C for 1h: then a condensation reaction is carried out at 50Pa high vacuum and 270°C for 2.5h. After the reaction is completed, the melt is pressed out with nitrogen, water-cooled, and pelletized to obtain tungsten sulfide modified PTT chips; (3) Tungsten sulfide modified PTT chips and PET chips with a viscosity of 0.47 dl / g were dried separately and melted at 270°C to obtain tungsten sulfide modified PTT spinning melt and PET spinning melt; the two spinning melts were respectively fed 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 275°C, and the fibers were ejected from the spinneret to form filaments; the filaments were cooled, oiled, stretched and shaped, and wound (the first hot roller temperature was 85°C, the second hot roller temperature was 165°C; the stretching ratio was 4; the side blowing speed was 0.8 m / s) to obtain a parallel structure composite fiber (specification 100 dtex / 36f) with a dumbbell-shaped fiber cross section.

[0048] Comparative Example 1 The difference from Example 1 is that in step (2), the amount of modified tungsten sulfide monolayer nanosheets added to the mixed slurry is 2.0 wt%.

[0049] Comparative Example 2 The difference from Example 1 is that during the composite spinning process, the spinning box temperature is 285°C, the first hot roller temperature is 105°C, and the second hot roller temperature is 185°C. The specific steps include: (1) Preparation of modified tungsten sulfide monolayer nanosheets: dissolve hexadecyltrimethylammonium bromide in deionized water at room temperature until completely dissolved to obtain a first solution (the mass concentration of hexadecyltrimethylammonium bromide is 0.3%); dissolve sodium tungstate and thiourea in water to obtain a second solution (the mass concentrations of sodium tungstate 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 tungsten sulfide monolayer nanosheets; (2) Add the modified tungsten sulfide monolayer nanosheets to PDO , obtaining a PDO solution of modified tungsten sulfide (mass concentration of 2.5%); terephthalic acid, PDO, catalyst (tetrabutyl titanate), and propylene glycol solution of modified tungsten sulfide were mixed in a reaction vessel and then slurried, wherein the addition amount of tungsten sulfide single-layer nanosheets in the mixed slurry was 0.5wt%, the alcohol-acid ratio was 1:1.5, and the addition amount of the catalyst was 100ppm; nitrogen was introduced into the reaction vessel, the initial pressure was increased to 0.10Mpa, the temperature was raised to 245°C, and then the pressure was increased to 0.3Mpa, the esterification reaction was carried out for 2.5h, and the by-product water was continuously removed; after the esterification was completed, a pre-condensation reaction was carried out at -0.09Mpa vacuum and 260°C for 1h; then a condensation reaction was carried out at 50pa high vacuum and 270°C for 2.5h. After the reaction was completed, the melt was pressed out with nitrogen, water-cooled, and pelletized to obtain tungsten sulfide modified PTT chips; (3) Tungsten sulfide modified PTT chips and PET chips with a viscosity of 0.47 dl / g were dried separately and melted at 260°C to obtain tungsten sulfide modified PTT spinning melt and PET spinning melt; the two spinning melts were respectively fed 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; the filaments were cooled, oiled, stretched and shaped, and wound (the first hot roller temperature was 105°C, the second hot roller temperature was 185°C; the stretching ratio was 3.5; the side blowing speed was 0.8 m / s) to obtain a parallel structure composite fiber (specification 100 dtex / 36f), and the fiber cross section was dumbbell-shaped.

[0050] Comparative Example 3 The difference from Example 1 is that the tungsten sulfide is not modified.

[0051] The following steps are involved: Preparation of tungsten sulfide monolayer nanosheets: Sodium tungstate and thiourea are dissolved in water, and the pH of the solution is adjusted to less than 1 with concentrated hydrochloric acid to obtain a solution (the mass concentrations of sodium tungstate and thiourea are 0.5% and 0.85%, respectively). The solution is then quickly transferred to a polytetrafluoroethylene-lined autoclave, sealed, and treated at 180°C for 24 hours, and naturally cooled to room temperature. The solution is then centrifuged and washed with deionized water and ethanol, respectively, and the tungsten sulfide monolayer nanosheets are collected. (2) Adding modified tungsten sulfide monolayer nanosheets to PDO to obtain a PDO solution of modified tungsten sulfide (mass concentration is 2.5%); mixing terephthalic acid, PDO, catalyst (tetrabutyl titanate), and propylene glycol solution of modified tungsten sulfide in a reaction vessel and beating the mixture, wherein the amount of tungsten sulfide added to the mixed slurry is 0.5wt%, the alcohol-acid ratio is 1:1.5, and the amount of catalyst added is 100ppm; nitrogen is introduced into the reaction vessel, the initial pressure is increased to 0.10Mpa, the temperature is raised to 245℃, and then the pressure is increased to 0.3Mpa, and 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 260℃ for 1h; then a condensation reaction is carried out at 50pa high vacuum and 270℃ for 2.5h. After the reaction is completed, the melt is pressed out with nitrogen, water-cooled, and pelletized to obtain tungsten sulfide modified PTT chips; (3) Tungsten sulfide modified PTT chips and PET chips with a viscosity of 0.47 dl / g were dried separately and melted at 260°C to obtain tungsten sulfide modified PTT spinning melt and PET spinning melt; the two spinning melts were respectively fed 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 270°C, and the fibers were ejected from the spinneret to form filaments; the filaments were cooled, oiled, stretched and shaped, and wound (the first hot roller temperature was 75°C, the second hot roller temperature was 150°C; the stretching ratio was 3.5; the side blowing speed was 0.8 m / s) to obtain a parallel structure composite fiber (specification 100 dtex / 36f) with a dumbbell-shaped fiber cross section.

[0052] Comparative Example 4 The difference from Example 1 is that the modifier for modifying tungsten sulfide is triethanolamine stearate, and the method specifically includes the following steps: Preparation of modified tungsten sulfide 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 tungstate and thiourea in water to obtain a second solution (the mass concentrations of sodium tungstate 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 tungsten sulfide monolayer nanosheets; (2) Adding modified tungsten sulfide monolayer nanosheets to PDO to obtain a PDO solution of modified tungsten sulfide (mass concentration is 2.5%); mixing terephthalic acid, PDO, catalyst (tetrabutyl titanate), and propylene glycol solution of modified tungsten sulfide in a reaction vessel and beating the mixture, wherein the amount of tungsten sulfide monolayer nanosheets added to the mixed slurry is 0.5wt%, the alcohol-acid ratio is 1:1.5, and the amount of catalyst added is 100ppm; nitrogen is passed through the reaction vessel, the initial pressure is increased to 0.10Mpa, the temperature is raised to 245℃, and then the pressure is increased to 0.3Mpa, and 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 260℃ for 1h; then a condensation reaction is carried out at 50pa high vacuum and 270℃ for 2.5h. After the reaction is completed, the melt is pressed out with nitrogen, water-cooled, and pelletized to obtain tungsten sulfide modified PTT chips; (3) Tungsten sulfide modified PTT chips and PET chips with a viscosity of 0.47 dl / g were dried separately and melted at 260°C to obtain tungsten sulfide modified PTT spinning melt and PET spinning melt; the two spinning melts were respectively fed 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 270°C, and the fibers were ejected from the spinneret to form filaments; the filaments were cooled, oiled, stretched and shaped, and wound (the first hot roller temperature was 75°C, the second hot roller temperature was 150°C; the stretching ratio was 3.5; the side blowing speed was 0.8 m / s) to obtain a parallel structure composite fiber (specification 100 dtex / 36f) with a dumbbell-shaped fiber cross section.

[0053] The performance of the fibers prepared in the above examples and comparative examples was evaluated, and the specific results are shown in Table 1.

[0054] Strength test: in accordance with the standard of GB / T-14337 Test method for tensile properties of filaments; Elasticity test: in accordance with the standards of "GB / T-14338 Test method for crimping performance of filaments" and "GB / T-6505-2008 Test method for thermal shrinkage of chemical fibers and filaments"; Antibacterial property test: According to the standards of FZ / T 73023-2006 and GB / T 20944-2007, the fiber prepared in the embodiment of the present invention has an inhibition rate of ≥90% against Escherichia coli, Staphylococcus aureus, and Candida albicans, and is considered to have excellent antibacterial properties and is a high-quality product. Far infrared performance test: According to the standard "GB / T 30127-2013 Testing and evaluation of far infrared performance 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.

[0055] Table 1 As shown in Table 1, the parallel composite fibers obtained in various embodiments of the present invention have the characteristics of high strength and excellent functional effects. The tungsten sulfide components are evenly dispersed without agglomeration. The fibers also have good elasticity, antibacterial and far-infrared properties, and are multifunctional and high-value-added fibers.

[0056] The data of Comparative Example 1 show that the proportion of tungsten sulfide added during polymerization is too high, resulting in the inability to fully and evenly disperse the tungsten sulfide and causing partial agglomeration, which is not conducive to its subsequent processing and reduces the mechanical properties of the fiber.

[0057] The data of Comparative Example 2 show that the spinning temperature of the obtained fiber is too high, resulting in partial degradation of the fiber, 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 performance is poor.

[0058] The data of Comparative Example 3 show that the tungsten sulfide 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 tungsten sulfide can better disperse it evenly, prevent agglomeration, and make the fiber have excellent performance.

[0059] The data of Comparative Example 4 show that the modification effect of the hexadecyltrimethylammonium bromide of the present invention as a modifier is better, while the use of other cationic surfactants cannot achieve the same effect. The main reason may be that the affinity and dispersibility of other cationic surfactants in the raw materials for tungsten sulfide preparation are limited, and after the tungsten sulfide 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 deteriorate.

[0060] Unless otherwise specified, the raw materials and equipment used in the present invention are commonly used in the art; the methods used in the present invention are conventional methods in the art unless otherwise specified.

[0061] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for preparing tungsten sulfide modified PTT antibacterial elastic composite fiber, characterized in that include: 1) Hexadecyltrimethylammonium bromide-modified tungsten sulfide monolayer nanosheets were added to the synthetic raw materials of PTT polyester to obtain a mixed slurry, and tungsten sulfide-modified PTT chips were prepared by in-situ polymerization; 2) Tungsten sulfide modified PTT chips and PET chips were used as raw materials and two-component composite spinning was performed to prepare tungsten sulfide modified PTT antibacterial elastic composite fibers.

2. The preparation method according to claim 1, wherein: In step 1), the content of the cetyltrimethylammonium bromide-modified tungsten sulfide monolayer nanosheets in the mixed slurry is 0.1-1 wt %.

3. The preparation method according to claim 1 or 2, characterized in that: In step 1), the method for preparing the hexadecyltrimethylammonium bromide modified tungsten sulfide monolayer nanosheets comprises: a) adding an aqueous solution containing hexadecyltrimethylammonium bromide as a first solution and an aqueous solution containing sodium tungstate and thiourea as a second solution dropwise to the first solution under ultrasonic assistance, and adjusting the pH to less than 1 after the addition to obtain a mixed solution; b) heating the mixed solution to react, thereby obtaining hexadecyltrimethylammonium bromide-modified tungsten sulfide monolayer nanosheets.

4. The preparation method according to claim 3, wherein: In step a), The concentration of hexadecyltrimethylammonium bromide in the first solution is 0.1-0.5 wt %; The concentrations of sodium tungstate and thiourea in the second solution are 0.4-0.6wt% and 0.8-0.9wt% respectively; The mass ratio of the first solution to the second solution is (0.8-1.2):

1.

5. The preparation method according to claim 3, wherein: In step b), the heating reaction is carried out at 160-200° C. for 22-26 hours.

6. The preparation method according to claim 1, wherein: In step 1), the preparation of the mixed slurry includes: adding hexadecyltrimethylammonium bromide-modified tungsten sulfide monolayer nanosheets to propylene glycol to obtain a solution with a concentration of 2-3 wt%, and then mixing with terephthalic acid, 1.3-propylene glycol and a catalyst to obtain a mixed slurry; the molar ratio of alcohol to acid in the mixed slurry is 1:1.2-2.0, and the content of the catalyst is 90-100 ppm.

7. The preparation method according to claim 1 or 6, characterized in that: In step 1), the in-situ polymerization includes: an esterification reaction for 2 to 3 hours under an inert atmosphere at a pressure of 0.3 to 0.35 MPa and a temperature of 235 to 255° C., while continuously removing by-product water; after the esterification is completed, a pre-polycondensation reaction is carried out at a vacuum of -0.09 to -0.1 MPa and a temperature of 260 to 270° C. for 0.5 to 1 hour; and then a polycondensation reaction is carried out at a vacuum of less than 70 Pa and a temperature of 260 to 270° C. for 2 to 3 hours.

8. The preparation method according to claim 1, wherein: In step 2), the spinning box temperature of the two-component composite spinning is 265-275°C.

9. The preparation method according to claim 1 or 8, characterized in that: In step 2), the filaments obtained by the bicomponent composite spinning are cooled, oiled, stretched, shaped and wound to obtain composite fibers; The cooling method adopts 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.

10. The preparation method according to claim 1, characterized in that: In step 2), The viscosity of the PET slice is 0.4-0.5 dl / g; The mass ratio of the PTT slices to the PET slices is 40:60 to 60:40.

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