A spinning dope for high-strength creep-resistant and antistatic nylon 66 fiber and a preparation method thereof

Abstract

The application provides a spinning dope for high-strength creep-resistant and antistatic nylon 66 fibers and a preparation method thereof. In the method, a physical filling method is used, and metal oxides and MOFs are used for filling modification of PA66. That is, in the melting process of PA66, the metal oxides and MOFs form physical crosslinking points with PA66, the intermolecular force is enhanced, the doped particles can form physical crosslinking points between molecules, the intermolecular force is enhanced, the intermolecular steric hindrance is effectively increased and the molecular chain slipping is prevented, and the anti-creep effect is produced. In addition, after the spinning dope is modified and finished, the conductivity of the PA66 fiber can be greatly improved, and the antistatic ability of the fiber is enhanced. The PA66 fiber obtained by using the method has the advantages of high anti-creep strength and excellent antistatic performance under the synergistic action of the metal oxides and the MOFs.

Description

Technical Field

[0001] This invention relates to the field of melt spinning technology, specifically to a high-strength, creep-resistant, and antistatic nylon 66 fiber spinning slurry and its preparation method. Background Technology

[0002] Since W.H. Carothers invented nylon 66 (PA66) in 1935, DuPont established the world's first nylon 66 production facility with an annual output of 4,000 tons in 1939. As people's understanding of nylon 66 deepened, high molecular weight, high viscosity nylon 66 emerged, and equipment related to its preparation gradually improved. The performance of nylon 66 was also continuously enhanced. Current nylon 66 possesses excellent properties such as high mechanical strength, good toughness, heat resistance, wear resistance, and corrosion resistance. With matching equipment and processes, high-performance nylon 66 can be produced industrially. The large-scale production of high-performance nylon 66 has led to its widespread application in both civilian and military fields.

[0003] PA66 fiber is produced by polyamide resin obtained through a condensation reaction of ethylenediamine (containing 6 carbon atoms) and adipic acid (containing 6 carbon atoms), followed by melt spinning to obtain polyamide fiber. PA66 fiber molecular chains exhibit high order and regularity, excellent molecular chain orientation and crystallinity, and intermolecular forces such as hydrogen bonds and van der Waals forces. This gives it excellent mechanical properties as well as good rigidity and strength. However, due to the regular molecular chain structure of PA66, with fewer branches and heterochains and fewer intermolecular forces, the molecular chains are prone to slippage. During use, the fiber undergoes irreversible deformation, resulting in poor shape retention and easy deformation leading to creep. Furthermore, its antistatic properties are poor, easily generating static electricity during use and compromising the original comfort of the fiber.

[0004] It is evident that providing a spinning sizing agent and preparation process for nylon 66 fibers with high creep resistance and antistatic properties is of great significance to the industry. Summary of the Invention

[0005] In view of this, the present invention provides a high-strength, creep-resistant, and antistatic spinning sizing agent for nylon 66 fibers and its preparation method. In this spinning sizing agent, a physical filling method is employed, using metal oxides and MOFs to modify PA66. Specifically, during the melting process of PA66, the metal oxides and MOFs form physical cross-linking points with PA66, enhancing intermolecular forces. The doped particles can form physical cross-linking points between molecules, further strengthening intermolecular forces, effectively increasing steric hindrance and preventing molecular chain slippage, thus producing an anti-creep effect. Furthermore, after doping and modifying the spinning sizing agent, the electrical conductivity of PA66 fibers can be greatly improved, enhancing the fiber's antistatic ability. PA66 fibers obtained using this method exhibit strong creep resistance and excellent antistatic properties due to the synergistic effect of the metal oxides and MOFs.

[0006] The technical solution of the present invention is as follows:

[0007] A spinning sizing agent for high-strength, creep-resistant, and antistatic nylon 66 fibers comprises the following components in parts by weight:

[0008] 94-100 parts PA66 powder, 1-5 parts metal oxide, 0.5-1 part metal-organic framework (MOF) compound, 0.1-0.5 parts coupling agent, 0.1-0.5 parts surfactant, 0.1-0.5 parts wetting and dispersing agent, and 0.2-0.5 parts electrolyte.

[0009] Preferably, the PA66 powder has an average particle size of 5 μm and a bulk density of 0.5 g / cm³. 3 It has a melting point of 265℃; powdered PA66 raw material can improve the spinnability of spinning sizing agents and improve the surface morphology and mechanical properties of fibers.

[0010] Preferably, the metal oxide is one or more of nano-iron oxide, nano-copper oxide, and nano-alumina, and the average particle size of the metal oxide is 300 nm; the metals in the metal oxide all have electrical conductivity and low cost, which can achieve the purpose of antistatic at low cost.

[0011] Preferably, the MOF is one or more of MOF-UiO-66(Zr), HKUST-1, ZIF-8, and MILs, and the average particle size of the MOF is 200 nm. The excellent specific surface area and porous structure of the MOF, and its special microscopic surface efficiency promote the expression of intermolecular forces in the fiber molecular chains, thereby improving the conductivity and creep resistance of the product when it is added to PA66 fiber.

[0012] Preferably, the coupling agent is a silane coupling agent; the silane coupling agent is one or more of trichlorovinylsilane, triethoxyvinylsilane, γ-aminopropyltriethoxysilane, and trichloropropylene silane; silane coupling agents are relatively mature products on the market, with readily available materials and low cost. By adding coupling agents, the crosslinking and adhesion between PA66 powder and metal oxides and MOFs can be promoted, thereby improving the uniformity and spinnability of the spinning sizing agent.

[0013] Preferably, the surfactant is an anionic surfactant, specifically one or more of alkylbenzene sulfonate, polysiloxane, fatty alcohol polyoxyethylene ether phosphate, and polyoxyethylene monolaurate.

[0014] Preferably, the wetting and dispersing agent is sodium diisooctyl sulfosuccinate, with a solid content of 70-75%, a pH of 5.0-7.0, and a viscosity of <200.

[0015] The addition of surfactants and wetting and dispersing agents can enhance the dispersion uniformity of spinning sizing agents, improve the compatibility between components, promote the adhesion and cross-linking between components, and enhance the spinnability of the final spinning sizing agent.

[0016] Preferably, the electrolyte comprises polyaniline (PAn) and lithium chloride (LiCl), with a mass ratio of polyaniline (PAn) to lithium chloride (LiCl) of 1:1.

[0017] The preparation method of the above-mentioned spinning sizing agent is as follows:

[0018] (1) Material preparation: Weigh the materials according to the proportions of each component in the spinning sizing agent and set them aside for later use;

[0019] (2) Preparation of metal oxide systems:

[0020] Metal oxides and electrolytes are added to a beaker, and a certain amount of deionized water is added and stirred at room temperature for 2-3 hours to obtain mixed slurry A. Mixed slurry A is then placed in a ball mill and ground for 3-4 hours to make the average particle size of the particles in mixed slurry A less than 150 nm, resulting in a uniformly dispersed mixed slurry B. Mixed slurry B is filtered, and the filter cake is dried to remove moisture, resulting in a uniformly dispersed metal oxide system for later use.

[0021] This process can obtain a uniformly dispersed metal oxide system, and the ball milling process reduces the particle size of the metal oxide, laying the foundation for uniform mixing in the subsequent preparation of PA66 spinning sizing agent.

[0022] (3) Preparation of MOF materials:

[0023] MOF, wetting and dispersing agent, and surfactant are added to a beaker and stirred at room temperature for 2-3 hours to obtain mixture A. Then, mixture A is placed in a ball mill for ball milling for 3-4 hours. When the average particle size of MOF in mixture A is less than 100 nm, the milling is stopped to obtain mixture B. The well-milled and uniformly dispersed mixture B is filtered, the filter is collected and dried to obtain MOF material, which is then bagged for later use.

[0024] MOF, when mixed with wetting and dispersing agents and surfactants and ball-milled, can produce a mixed system with good compatibility and adhesion. This mixed system can only be used to prepare PA66 fibers with excellent creep resistance and antistatic properties when mixed with metal oxide systems.

[0025] (4) Preparation of PA66 spinning sizing dispersion system:

[0026] PA66 powder, surfactant and coupling agent are added to a mixing tank and stirred at 300-500 rpm for 30-50 min. Then the metal oxide system of step (2) and MOF material of step (3) are added and stirred at 400-700 rpm for 2-3 h to obtain a uniformly mixed PA66 spinning sizing agent. In order to ensure the spinnability of the spinning sizing agent, the dispersion of particles (particle size and particle size distribution) in the spinning sizing agent is measured using a dynamic light scattering analyzer (DLS).

[0027] The uniformity of dispersion and the compatibility between components of spinning sizing agent are the main factors to ensure the performance of the sizing agent. By setting the raw material composition of the spinning sizing agent, the compatibility between the raw materials is good. By using the preparation method of the spinning sizing agent, the raw materials are evenly dispersed. Thus, the spinning sizing agent can be used to prepare spun fibers with high creep resistance and high antistatic properties.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] 1. The method for preparing modified PA66 spinning sizing fiber provided by this invention has the advantages of simple operation and excellent spinnability. Among them, the addition of metal oxides and MOFs in the melt spinning sizing agent can enable PA66 molecular chains to form numerous physical cross-linking points during the pre-spinning process, forming a three-dimensional interconnected structure, promoting molecular chain alignment and improving its orientation. The improved orientation and crystallinity of PA66 molecular chains can prevent molecular chains from slipping and moving when subjected to external forces, thereby the prepared PA66 fiber has good anti-creep mechanical properties.

[0030] 2. In this invention, PA66 fibers with added metal oxides and MOFs have a large specific surface area and porosity, forming a three-dimensional cross-linked conductive network. The electrolyte is distributed in the three-dimensional cross-linked conductive network, enhancing the conductivity of the fibers and achieving an antistatic effect. In addition, the synergistic effect of the metal oxides and MOFs induces the construction of a three-dimensional interconnected conductive network between PA66 fibers, increasing the final conductivity of the material and achieving an antistatic effect.

[0031] 3. In the pre-spinning of PA66 fibers, the temperature settings of the eight heating zones of the twin-screw extruder cause the PA66 molecular chains to open up and rearrange their orientation. The rotational speed of the twin screws provides shear force to the spinning slurry, causing the PA66 molecular chains to crystallize. In the post-spinning, the melt spinning-super-stretching method can further improve the orientation and crystallinity of the PA66 molecular chains, effectively constructing a three-dimensional cross-linked conductive network. The above settings allow the components in the spinning slurry to fully combine and react, resulting in PA66 fibers with good creep resistance and antistatic properties.

[0032] 4. The PA66 fiber prepared by this invention has excellent anti-creep mechanical properties and antistatic properties, and can play a vital role in civilian textiles, national defense and military industries and aerospace fields. Detailed Implementation

[0033] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0034] In the following embodiments and comparative examples of the present invention, the PA66 powder is in the state after being ground by a grinder, with an average particle size of 5 μm and a bulk density of 0.5 g / cm³. 3 The melting point is 265℃; the electrolyte is composed of PAn and LiCl, with a mass ratio of PAn to LiCl of 1:1.

[0035] Example 1

[0036] A method for preparing a spinning sizing agent, the process of which is as follows:

[0037] (1) Preparation of metal oxide systems:

[0038] 50g of nano-iron oxide and 2g of electrolyte were mixed and added to a beaker. Deionized water was added and stirred at room temperature for 2.5h to obtain mixed slurry A. Mixed slurry A was placed in a ball mill and ground for 3h to make the average particle size of the particles in mixed slurry A less than 150nm, so as to obtain a uniformly dispersed mixed slurry B. Mixed slurry B was filtered and dried to remove moisture, so as to obtain a uniformly dispersed metal oxide system for later use.

[0039] (2) Preparation of MOF materials:

[0040] 5g of MOF-UiO-66(Zr), 1g of sodium diisooctyl sulfosuccinate, and 1g of alkylbenzene sulfonate were added to beakers and stirred at room temperature for 2.5h to obtain mixture A. Then, mixture A was placed in a ball mill and ground for 3.5h. When the average particle size of MOF in mixture A was less than 100nm, the grinding was stopped to obtain mixture B. The well-ground and uniformly dispersed mixture B was filtered and dried to obtain MOF material, which was then bagged for later use.

[0041] (3) Preparation of PA66 spinning sizing dispersion system:

[0042] Add 470g of PA66 powder, 2.5g of alkylbenzene sulfonate and 2g of silane coupling agent to a mixing tank and stir at 450rpm for 45min. Then add 25g of the metal oxide system from step (1) and 5g of the MOF material from step (2) and continue stirring at 600rpm for 3h to obtain a uniformly mixed PA66 spinning slurry.

[0043] To ensure the spinnability of the spinning sizing agent, the dispersion of particles (particle size and particle size distribution) in the spinning sizing agent was measured using a dynamic light scattering analyzer (DLS), as shown in Table 2.

[0044] The PA66 spinning sizing agent prepared in this embodiment is designated as PA66-1.

[0045] Comparative Example 1

[0046] The difference between Comparative Example 1 and Example 1 is that no metal oxides and MOFs are added to the PA66 spinning slurry.

[0047] The PA66 spinning sizing agent prepared above is designated as PA66-1.1.

[0048] Example 2

[0049] A method for preparing a spinning sizing agent, the process of which is as follows:

[0050] (1) Preparation of metal oxide systems:

[0051] Same as Example 1.

[0052] (2) Preparation of MOF materials:

[0053] Same as Example 1.

[0054] (3) Preparation of PA66 spinning sizing dispersion system:

[0055] Add 490g of PA66 powder, 2.5g of alkylbenzene sulfonate and 2g of silane coupling agent to a mixing tank and stir at 450rpm for 45min. Then add 5g of the metal oxide system from step (1) and 5g of the MOF material from step (2) and continue stirring at 600rpm for 3h to obtain a uniformly mixed PA66 spinning slurry.

[0056] To ensure the spinnability of the spinning sizing material, the dispersion of particles (particle size and particle size distribution) in the spinning sizing material was measured using a dynamic light scattering analyzer (DLS). The results are shown in Table 2.

[0057] The PA66 spinning sizing agent prepared in this embodiment is designated as PA66-2.

[0058] Example 3

[0059] A method for preparing a spinning sizing agent, the process of which is as follows:

[0060] (1) Preparation of metal oxide systems:

[0061] Same as Example 1.

[0062] (2) Preparation of PA66 spinning sizing dispersion system:

[0063] Add 475g of PA66 powder, 2.5g of alkylbenzene sulfonate and 2g of silane coupling agent to a mixing tank and stir at 450rpm for 45min. Then add 25g of the metal oxide system from step (1) and continue stirring at 600rpm for 3h to obtain a uniformly mixed PA66 spinning slurry.

[0064] To ensure the spinnability of the spinning sizing material, the dispersion of particles (particle size and particle size distribution) in the spinning sizing material was measured using a dynamic light scattering analyzer (DLS). The results are shown in Table 2.

[0065] The PA66 spinning sizing agent prepared in this embodiment is designated as PA66-3.

[0066] Example 4

[0067] A method for preparing a spinning sizing agent, the process of which is as follows:

[0068] (1) Preparation of metal oxide systems:

[0069] Same as Example 1.

[0070] (2) Preparation of PA66 spinning sizing dispersion system:

[0071] Add 485g of PA66 powder, 2.5g of alkylbenzene sulfonate and 2g of silane coupling agent to a mixing tank and stir at 450rpm for 45min. Then add 15g of the metal oxide system from step (1) and continue stirring at 600rpm for 3h to obtain a uniformly mixed PA66 spinning slurry.

[0072] To ensure the spinnability of the spinning sizing material, the dispersion of particles (particle size and particle size distribution) in the spinning sizing material was measured using a dynamic light scattering analyzer (DLS). The results are shown in Table 2.

[0073] The PA66 spinning sizing agent prepared in this embodiment is designated as PA66-4.

[0074] Example 5

[0075] A method for preparing a spinning sizing agent, the process of which is as follows:

[0076] (1) Preparation of metal oxide systems:

[0077] Same as Example 1.

[0078] (2) Preparation of PA66 spinning sizing dispersion system:

[0079] Add 495g of PA66 powder, 2.5g of alkylbenzene sulfonate and 2g of silane coupling agent to a mixing tank and stir at 450rpm for 45min. Then add 5g of the metal oxide system from step (1) and continue stirring at 600rpm for 3h to obtain a uniformly mixed PA66 spinning slurry.

[0080] To ensure the spinnability of the spinning sizing material, the dispersion of particles (particle size and particle size distribution) in the spinning sizing material was measured using a dynamic light scattering analyzer (DLS). The results are shown in Table 2.

[0081] The PA66 spinning sizing agent prepared in this embodiment is designated as PA66-5.

[0082] Example 6

[0083] A method for preparing a spinning sizing agent, the process of which is as follows:

[0084] (1) Preparation of MOF materials:

[0085] Same as Example 1.

[0086] (2) Preparation of PA66 spinning sizing dispersion system:

[0087] Add 495g of PA66 powder, 2.5g of alkylbenzene sulfonate and 2g of silane coupling agent to a mixing tank and stir at 450rpm for 45min. Then add 5g of MOF material prepared in step (1) and continue stirring at 600rpm for 3h to obtain a uniformly mixed PA66 spinning slurry.

[0088] To ensure the spinnability of the spinning sizing material, the dispersion of particles (particle size and particle size distribution) in the spinning sizing material was measured using a dynamic light scattering analyzer (DLS). The results are shown in Table 2.

[0089] The PA66 spinning sizing agent prepared in this embodiment is designated as PA66-6.

[0090] Example 7

[0091] A method for preparing a spinning sizing agent, the process of which is as follows:

[0092] (1) Preparation of MOF materials:

[0093] Same as Example 1.

[0094] (2) Preparation of PA66 spinning sizing dispersion system:

[0095] Add 496g of PA66 powder, 2.5g of alkylbenzene sulfonate and 2g of silane coupling agent to a mixing tank and stir at 450rpm for 45min. Then add 4g of MOF material prepared in step (1) and continue stirring at 600rpm for 3h to obtain a uniformly mixed PA66 spinning slurry.

[0096] To ensure the spinnability of the spinning sizing material, the dispersion of particles (particle size and particle size distribution) in the spinning sizing material was measured using a dynamic light scattering analyzer (DLS). The results are shown in Table 2.

[0097] The PA66 spinning sizing agent prepared in this embodiment is designated as PA66-7.

[0098] Example 8

[0099] A method for preparing a spinning sizing agent, the process of which is as follows:

[0100] (1) Preparation of MOF materials:

[0101] Same as Example 1.

[0102] (2) Preparation of PA66 spinning sizing dispersion system:

[0103] Add 497g of PA66 powder, 2.5g of alkylbenzene sulfonate and 2g of silane coupling agent to a mixing tank and stir at 450rpm for 45min. Then add 3g of MOF material prepared in step (1) and continue stirring at 600rpm for 3h to obtain a uniformly mixed PA66 spinning slurry.

[0104] To ensure the spinnability of the spinning sizing material, the dispersion of particles (particle size and particle size distribution) in the spinning sizing material was measured using a dynamic light scattering analyzer (DLS). The results are shown in Table 2.

[0105] The PA66 spinning sizing agent prepared in this embodiment is designated as PA66-8.

[0106] Comparative Example 2

[0107] Preparation of PA66 spinning sizing dispersion system: 470g PA66 powder, 2.5g alkylbenzene sulfonate, and 2g silane coupling agent were added to a mixing tank and stirred at 450rpm for 45min. Then, 25g of untreated and ground metal oxide and 5g of MOF were added, and stirring was continued at 600rpm for 3h to obtain a uniformly mixed PA66 spinning sizing. To ensure the spinnability of the spinning sizing, the dispersibility (particle size and particle size distribution) of the particles in the spinning sizing was measured using a dynamic light scattering analyzer (DLS).

[0108] The PA66 spinning sizing agent prepared above is designated as PA66-1.2.

[0109] The proportions of PA66, metal oxide system, and MOF material in the above embodiments and comparative examples are shown in Table 1 below:

[0110] Table 1. Composition of effective components in nylon 66 spinning sizing agent during case implementation

[0111]

[0112] After grinding, the average particle size of the metal oxides, MOFs, and the average particle size of the PA66 spinning sizing dispersion system are shown in Table 2, as follows:

[0113] Table 2 Particle Size Statistics

[0114]

[0115] Example 9

[0116] The spinning slurries prepared in Examples 1-8 and Comparative Examples 1-2 were melt-spun.

[0117] A twin-screw extruder is used, with a screw diameter of 26mm and a length-to-diameter ratio of 52. The spinning operation includes pre-spinning and post-spinning processes. The twin-screw extruder is manufactured by Jiangsu Chengmeng Equipment Co., Ltd., as detailed below:

[0118] Pre-spinning process: The prepared PA66 spinning slurry is added to a twin-screw extruder. The temperatures of the eight heating zones of the twin-screw are set as follows: 250℃ for the first heating zone, 265℃ for the second heating zone, 265℃ for the third heating zone, 285℃ for the fourth heating zone, 290℃ for the fifth heating zone, 305℃ for the sixth heating zone, 305℃ for the seventh heating zone, and 295℃ for the eighth heating zone. After each heating zone reaches the set temperature, the water-oil pump is started and run for 15 minutes. Then, the twin-screw extruder is started and the twin-screw speed is set to 65 rpm. Subsequently, the spinning slurry is added to the feed inlet. Under the action of the heating zones of the twin-screw extruder, the polymer molecular chains of the spinning slurry melt, and finally, PA66 nascent fibers are obtained by extrusion through the spinneret.

[0119] Post-spinning process: The PA66 nascent fibers obtained from the pre-spinning are cooled by a 25°C water bath, and then the cooled fibers are pre-stretched by a stretching device, and then subjected to multi-stage hot stretching to obtain PA66 fibers with excellent mechanical properties.

[0120] In the spinning sizing agent, PA66 in the eight heating zones of a twin-screw extruder is subjected to shearing force provided by the twin screws, causing the PA66 molecular chains to open up and rearrange their orientation, resulting in crystallization. The resulting PA66 nascent fibers have good orientation and crystallinity. Furthermore, the addition of MOFs with surface effectiveness can improve the specific surface area and porosity of the fiber material. The final fibers are characterized by large specific surface area and high porosity.

[0121] The PA66 fibers prepared in Examples 1-8 and Comparative Examples 1-2 were named, in order, sample PA66-1, sample PA66-2, sample PA66-3, sample PA66-4, sample PA66-5, sample PA66-6, sample PA66-7, sample PA66-8, sample PA66-1.1, and sample PA66-1.2.

[0122] Material property testing

[0123] Mechanical property testing: The prepared PA66 fibers were subjected to mechanical property testing under a universal tensile testing machine to obtain their tensile breaking strength and tensile breaking modulus.

[0124] The mechanical tensile properties of PA66 fiber were tested using a universal tensile testing machine: a monofilament was clamped at both ends with a clamping distance of 20 mm, and the tensile speed was 20 mm / min.-1 Ten parallel samples were taken from each fiber, and the average value was calculated to obtain the tensile breaking strength and initial modulus of PA66 fiber. In a constant temperature and humidity environment, PA66 fiber samples were clamped at both ends of the holder, and the machine was pre-tensioned to 0.05 cN / dtex. Then, a constant force of 25% of the fiber breaking load was applied, and creep was maintained for a period of time. The final fiber length was recorded, and the fiber creep rate was calculated.

[0125] Conductivity testing: Conductivity testing was conducted according to GB / T 1410-2006 (IEC 60093) Test methods for volume resistivity and surface resistivity of solid insulating materials. The prepared PA66 fibers were placed in a conductivity meter for testing, and the surface resistivity of the fibers was obtained to characterize their conductivity. The experimental results are shown in Table 3 below:

[0126] Table 3 Mechanical and electrical properties of the prepared PA66 fibers

[0127]

[0128] The test results in the table above show that the mechanical and electrical properties of PA66 fibers with the addition of metal oxides and MOFs have been improved accordingly. The creep rate can be reduced by up to 50%, and the surface resistivity can be reduced by up to 5 orders of magnitude.

[0129] Adding only one of metal oxides or MOFs to the spinning sizing agent will enhance the performance of the final PA66 fiber, but it will not be as superior as the fiber prepared by adding both components simultaneously. Performance tests of PA66 fibers prepared with a single component show that adding a trace amount (0.5%-1.0%) of MOF can achieve similar mechanical and electrical properties to PA66 fibers prepared with a small amount (1.0%-5.0%) of metal oxide, indicating that adding a trace amount of MOF can have a more significant modifying effect on the final fiber performance. When both components are added simultaneously, the PA66 fiber exhibits the best performance, indicating that the two components can exert a synergistic effect to optimize fiber performance.

[0130] Furthermore, Comparative Example 2 shows that when metal oxides and MOFs are directly doped with PA66 without pretreatment and grinding, the mechanical and electrical properties of the final PA66 fibers are not significantly improved. This indicates that pretreatment and grinding of metal oxides and MOFs before doping with PA66 to prepare spinning slurry can have a very important positive impact on the performance of the final fibers.

[0131] The simultaneous addition of metal oxides and MOF materials resulted in excellent mechanical and electrical properties in PA66 fibers. Furthermore, increasing the PA solids content slightly decreased the final fiber performance. This indicates that the simultaneous addition of metal oxides and MOF materials can exert a synergistic effect, optimizing the performance of the prepared PA66 fibers. Moreover, changes in the PA solids content also have a certain impact on the final fiber properties.

[0132] In summary, this invention successfully prepared a high-strength, creep-resistant, and antistatic PA66 fiber using melt spinning-super-stretching technology. By doping metal oxides and MOFs during the melt spinning slurry preparation process, a synergistic network of metal oxides and MOFs was constructed, increasing the orientation and crystallinity of the polymer molecular chains and building a three-dimensional conductive network within the fiber. This significantly enhanced the creep resistance and antistatic effect of the PA66 fiber. Mechanical and electrical property tests revealed that the PA66 fiber prepared with a PA66 solid content of 94%, a metal oxide content of 5%, and a MOF content of 1% yielded the best mechanical strength, modulus, creep rate, and surface resistivity.

[0133] Although the present invention has been described in detail with reference to preferred embodiments, it is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the scope of the claims.

Claims

1. A spinning sizing agent for high-strength, creep-resistant, and antistatic nylon 66 fibers, characterized in that, The components include the following parts by weight: 94-100 parts PA66 powder, 1-5 parts metal oxide, 0.5-1 part metal-organic framework (MOF), 0.1-0.5 parts coupling agent, 0.1-0.5 parts surfactant, 0.1-0.5 parts wetting and dispersing agent, and 0.2-0.5 parts electrolyte; The preparation method of the high-strength, creep-resistant, and antistatic nylon 66 fiber spinning sizing agent is as follows: (1) Material preparation: Weigh the materials according to the proportions of each component in the spinning sizing agent and set them aside for later use; (2) Preparation of metal oxide systems: Metal oxides and electrolytes are added to a beaker, and deionized water is added and stirred at room temperature for 2-3 hours to obtain mixed slurry A. Mixed slurry A is then placed in a ball mill and ground for 3-4 hours to make the average particle size of the particles in mixed slurry A less than 150 nm, resulting in a uniformly dispersed mixed slurry B. Mixed slurry B is filtered, and the filter cake is dried to obtain a uniformly dispersed metal oxide system for later use. (3) Preparation of MOF materials: MOF, wetting and dispersing agent, and surfactant are added to a beaker and stirred at room temperature for 2-3 hours to obtain mixture A. Then, mixture A is placed in a ball mill for ball milling for 3-4 hours. When the average particle size of MOF in mixture A is less than 100 nm, the milling is stopped to obtain mixture B. The well-milled and uniformly dispersed mixture B is filtered, the filter is collected and dried to obtain MOF material, which is then bagged for later use. (4) Preparation of PA66 spinning sizing dispersion system: Add PA66 powder, surfactant and coupling agent to a mixing tank and stir at 300-500 rpm for 30-50 min. Then add the metal oxide system from step (2) and the MOF material from step (3) and continue stirring at 400-700 rpm for 2-3 h to obtain a uniformly mixed PA66 spinning slurry.

2. The spinning sizing agent for high-strength, creep-resistant, and antistatic nylon 66 fiber as described in claim 1, characterized in that, The PA66 powder has an average particle size of 5 μm and a bulk density of 0.5 g / cm³. 3 Its melting point is 265℃.

3. The spinning sizing agent for high-strength, creep-resistant, and antistatic nylon 66 fiber as described in claim 1, characterized in that, The metal oxide is one or more of nano iron oxide, nano copper oxide, and nano aluminum oxide, and the average particle size of the metal oxide is 300 nm.

4. The spinning sizing agent for high-strength, creep-resistant, and antistatic nylon 66 fiber as described in claim 1, characterized in that, The MOF is one or more of MOF-UiO-66(Zr), HKUST-1, ZIF-8, and MILs, and the average particle size of the MOF is 200 nm.

5. The spinning sizing agent for high-strength, creep-resistant, and antistatic nylon 66 fiber as described in claim 1, characterized in that, The coupling agent is a silane coupling agent; the silane coupling agent is one or more of trichlorovinylsilane, triethoxyvinylsilane, γ-aminopropyltriethoxysilane, and trichloropropenylsilane.

6. The spinning sizing agent for high-strength, creep-resistant, and antistatic nylon 66 fiber as described in claim 1, characterized in that, The surfactant is an anionic surfactant, specifically one or more of alkylbenzene sulfonates, polysiloxanes, fatty alcohol polyoxyethylene ether phosphates, and polyoxyethylene monolaurates.

7. The high-strength, creep-resistant, and antistatic nylon 66 fiber spinning sizing agent as described in claim 1, characterized in that, The wetting and dispersing agent is sodium diisooctyl sulfosuccinate, with a solid content of 70-75%, a pH of 5.0-7.0, and a viscosity of <200.

8. The spinning sizing agent for high-strength, creep-resistant, and antistatic nylon 66 fiber as described in claim 1, characterized in that, The electrolyte comprises polyaniline and lithium chloride, with a mass ratio of polyaniline to lithium chloride of 1:1.

Images