A method for preparing ultra-high molecular weight polyethylene fiber

Abstract

The present invention discloses a method for preparing ultra-high molecular weight polyethylene fibers, belonging to the technical field of polymer compound compositions and fiber materials. The method comprises the following steps: adding ultra-high molecular weight polyethylene powder to a solvent to dissolve and obtain a spinning solution; adding the spinning solution to a twin-screw extruder and extruding the mixture to obtain a spinning solution; filtering the spinning solution, extruding the mixture through a spinneret to obtain fiber filaments; extracting the fiber filaments, washing, drying, stretching, heat-setting, and then immersing them in a glue solution for a period of time, removing them, washing, and drying them to obtain the ultra-high molecular weight polyethylene fibers. By immersing the fiber filaments in the glue solution and adding a modified nano-alumina / carbon nanotube composite powder to the spinning solution, the present invention significantly improves the breaking strength and wear resistance of the polyethylene fibers.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer compound compositions and fiber materials, and more specifically, to a method for preparing ultra-high molecular weight polyethylene fibers. Background Art

[0002] Polyethylene fiber, a synthetic fiber made from polyethylene via melt spinning or solution spinning, holds a prominent position in the field of high-performance fibers. Polyethylene fiber is polymerized from a large number of ethylene monomers, resulting in a saturated carbon-carbon backbone and a high concentration of methylene groups (-CH2-). This regular and highly symmetrical molecular chain allows for close packing of polyethylene chains, resulting in a highly crystalline structure. Its crystallinity typically reaches 70% to 90%, endowing the fiber with numerous excellent properties. Due to its high strength, high modulus, high abrasion resistance, corrosion resistance, low density, and superior impact resistance, polyethylene fiber has numerous applications in defense, aerospace, sports, and other fields. In defense, polyethylene fiber is used in the manufacture of protective equipment such as bulletproof vests, helmets, and armor, as well as parachutes, ship cables, and radomes. In aviation, it is used in the manufacture of aircraft wings, fuselage structures, and satellite antennas, effectively reducing aircraft weight and improving fuel efficiency and performance.

[0003] In order to further improve the strength and wear resistance of ultra-high molecular weight polyethylene fibers, the currently commonly used method is to add a polymer wear-resistant coating or add organic or inorganic filler substances to the spinning solution for blending modification. With the development of various fields, the requirements for the various properties of fiber materials are becoming increasingly stringent, and the demand for the preparation and production of polyethylene fibers with higher strength and wear resistance has become more urgent. Summary of the Invention

[0004] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0005] In order to achieve these objects and other advantages according to the present invention, a method for preparing ultra-high molecular weight polyethylene fiber is provided, comprising the following steps:

[0006] Step 1: adding ultra-high molecular weight polyethylene powder into a solvent and dissolving it to obtain a spinning solution;

[0007] Step 2: adding the spinning solution into a twin-screw extruder, and blending and extruding to obtain a spinning solution;

[0008] Step 3: Filter the spinning solution, extrude it through a spinneret to obtain fiber filaments, extract the fiber filaments, wash, dry, stretch, heat-set them, immerse them in glue for a period of time, take them out, wash and dry them to obtain ultra-high molecular weight polyethylene fibers.

[0009] Preferably, in step 1, the weight average molecular weight of the ultra-high molecular weight polyethylene powder is 3 million to 10 million.

[0010] Preferably, in the step 1, the solvent is decalin, white oil or paraffin oil, and the mass percentage of the polyethylene powder to the solvent is 10% to 20%.

[0011] Preferably, in the step 2, the extrusion temperature of the twin-screw extruder is 130-180°C.

[0012] Preferably, in step three, the spinning diameter of the spinneret is 0.05 to 0.5 mm.

[0013] Preferably, in step three, the glue comprises, by weight: 20 to 40 parts of isooctyl acrylate, 5 to 20 parts of polyurethane, 1 to 5 parts of 1,6-hexanediol diacrylate, 5 to 10 parts of bisphenol A epoxy resin, and 1 to 5 parts of bisphenol F epoxy resin.

[0014] Preferably, the preparation method of the glue solution comprises:

[0015] S31. Pour isooctyl acrylate into a container and stir at a speed of 100 to 200 rpm to make the isooctyl acrylate flow evenly; slowly add polyurethane to the isooctyl acrylate and continue stirring to fully disperse and dissolve the polyurethane in the isooctyl acrylate. The stirring time is 15 to 30 minutes to obtain a mixed solution;

[0016] S32, adding 1,6-hexanediol diacrylate to the mixed solution, increasing the stirring speed to 300-500 rpm, and stirring for 10-30 minutes to obtain a mixed system;

[0017] S33. Add bisphenol A epoxy resin and bisphenol F epoxy resin to the mixed system, keep stirring for 20 to 30 minutes; add 0.5 to 2 wt% azobisisobutyronitrile to the mixed system, stir at 300 to 500 rpm for 1 to 3 hours to obtain a glue solution.

[0018] Preferably, in step 2, the modified nano-alumina / carbon nanotube composite powder is added to the twin-screw extruder, and the modified nano-alumina / carbon nanotube composite powder accounts for 2-5% of the mass of the polyethylene powder. The preparation method of the modified nano-alumina / carbon nanotube composite powder includes:

[0019] S1. Dispersing carbon nanotubes with a diameter of 10 to 20 nm in a 1 to 2 mol / L sodium hydroxide solution, heating to 60 to 80° C., keeping the temperature for 1 to 3 hours, cooling and filtering, and washing the carbon nanotubes with deionized water until neutral to obtain alkaline carbon nanotubes; dispersing the alkaline carbon nanotubes in anhydrous ethanol, adding KH550 silane coupling agent, and ultrasonically treating at 60° C. for 2 to 4 hours at an ultrasonic frequency of 40 kHz to obtain a carbon nanotube dispersion;

[0020] S2. Add aluminum isopropoxide and 0.1M ammonia solution to the carbon nanotube dispersion, and disperse ultrasonically at 40-55kHz at 60°C for 1-2 hours to obtain a reaction system; add deionized water dropwise to the reaction system, and stir at a constant temperature of 70-90°C for 4-8 hours to form an AlOOH-CNTs composite sol;

[0021] S3, the AlOOH-CNTs composite sol is freeze-dried and then calcined in three stages to obtain modified nano-alumina / carbon nanotube composite powder.

[0022] Preferably, in S1, the ratio of carbon nanotubes to sodium hydroxide solution is 1-5 g:250 mL; the ratio of alkalized carbon nanotubes, anhydrous ethanol, and KH550 silane coupling agent is 1-5 g:200-500 mL:0.1-2 g; and in S2, the ratio of alkalized carbon nanotubes, aluminum isopropoxide, ammonia solution, and deionized water is 1-5 g:20-60 g:10-20 mL:7-25 mL.

[0023] Preferably, in S3, the three-stage calcination specifically includes: heating to 300-500°C at a rate of 5°C / min and keeping warm for 1 hour; then heating to 600-700°C at a rate of 10°C / min and keeping warm for 2 hours; finally heating to 800-900°C at a rate of 20°C / min, keeping warm for 20-30 minutes, and cooling to room temperature to obtain modified nano-alumina / carbon nanotube composite powder.

[0024] The present invention includes at least the following beneficial effects: a method for preparing ultra-high molecular weight polyethylene fiber provided by the present invention, comprising adding a spinning solution and a modified nano-alumina / carbon nanotube composite powder into a twin-screw extruder for twin-screw extrusion, and immersing the fiber filaments in a dipping tank filled with glue for a period of time after spinning through a spinneret, thereby preparing an ultra-high molecular weight polyethylene fiber with high strength and excellent wear resistance; wherein the modified nano-alumina / carbon nanotube composite powder is prepared by a gel method, using nano-alumina to coat alkalized carbon nanotubes, and finally by three-stage gradient calcination to obtain the modified nano-alumina / carbon nanotube composite powder; the temperature is raised to 300-500°C at a rate of 5°C / min to remove residual solvent, the temperature is raised to 600-700°C at a rate of 10°C / min to form CO-Al bonding between the nano-alumina and the carbon nanotubes, and the temperature is raised to 800-900°C at a rate of 20°C / min to enhance the tightness of the combination of the nano-alumina powder and the carbon nanotubes and enhance the interface stress matching between the two materials.

[0025] The adhesive disclosed in the present invention uses isooctyl acrylate and polyurethane as main raw materials and 1,6-hexanediol diacrylate as an initiator. Isooctyl acrylate and polyurethane are cross-linked to form a viscous three-dimensional network, thereby improving the hardness of the adhesive layer formed by the adhesive. After adding bisphenol A epoxy resin and bisphenol F epoxy resin, the adhesive has aging resistance and reduces the crack propagation path of the polyethylene fiber surface coating. After the polyethylene fiber is immersed in the adhesive, an elastic wear-resistant layer is formed on the surface of the polyethylene fiber, which significantly improves the wear resistance of the polyethylene fiber.

[0026] Other advantages, objectives and features of the present invention will be reflected in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. DETAILED DESCRIPTION

[0027] The present invention is described in further detail below so that those skilled in the art can implement the invention with reference to the description.

[0028] It should be understood that terms such as “having”, “including” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof.

[0029] Example 1

[0030] This embodiment provides a method for preparing ultra-high molecular weight polyethylene fiber, comprising the following steps:

[0031] Step 1: adding 1000 g of ultra-high molecular weight polyethylene powder with a weight average molecular weight of 5 million to 5000 g of decalin to dissolve and obtain a spinning solution;

[0032] Step 2: Add the spinning solution into a twin-screw extruder and extrude at 130° C. to obtain a gel-like spinning solution;

[0033] Step 3: The spinning solution is filtered and extruded through a spinneret with a spinneret diameter of 0.05 mm to obtain fiber filaments. The fiber filaments are extracted, washed with clean water multiple times, dried at 60°C, stretched 120% at 150°C, and heat-set at 160°C to obtain fiber filaments. The fiber filaments are immersed in a dipping tank filled with glue for 3 hours, washed, and dried to obtain ultra-high molecular weight polyethylene fibers.

[0034] The preparation method of the glue solution includes:

[0035] S31, 200g of isooctyl acrylate was poured into a container, and the isooctyl acrylate was kept in a uniform flow state at a speed of 200rpm; 200g of polyurethane was slowly added to the isooctyl acrylate, and stirring was continued to fully disperse and dissolve the polyurethane in the isooctyl acrylate, and the stirring time was 30min to obtain a mixed solution;

[0036] S32, 10g of 1,6-hexanediol diacrylate was added to the mixture, the stirring speed was increased to 300 rpm, and the mixture was stirred for 30 min to fully mix the 1,6-hexanediol diacrylate with isooctyl acrylate and polyurethane to obtain a mixed system;

[0037] S33. Add 50 g of bisphenol A epoxy resin and 50 g of bisphenol F epoxy resin to the mixed system, keep stirring to uniformly disperse the bisphenol A epoxy resin and bisphenol F epoxy resin in the mixed system, and stir for 30 min; add 3 g of azobisisobutyronitrile to the mixed system, and stir at 300 rpm for 3 h to obtain a glue solution.

[0038] Example 2

[0039] This embodiment provides a method for preparing ultra-high molecular weight polyethylene fiber, comprising the following steps:

[0040] Step 1: adding 1000 g of ultra-high molecular weight polyethylene powder with a weight average molecular weight of 5 million to 5000 g of decalin to dissolve and obtain a spinning solution;

[0041] Step 2: Add the spinning solution into a twin-screw extruder and extrude at 130° C. to obtain a gel-like spinning solution;

[0042] Step 3: The spinning solution is filtered and extruded through a spinneret with a spinneret diameter of 0.05 mm to obtain fiber filaments. The fiber filaments are extracted, washed with clean water multiple times, dried at 60°C, stretched 120% at 150°C, and heat-set at 160°C to obtain fiber filaments. The fiber filaments are immersed in a dipping tank filled with glue for 3 hours, washed, and dried to obtain ultra-high molecular weight polyethylene fibers.

[0043] The preparation method of the glue solution includes:

[0044] S31, 300g of isooctyl acrylate is poured into a container, and the isooctyl acrylate is kept in a uniform flow state at a speed of 200rpm; 150g of polyurethane is slowly added to the isooctyl acrylate, and stirring is continued to fully disperse and dissolve the polyurethane in the isooctyl acrylate, and the stirring time is 30min to obtain a mixed solution;

[0045] S32, 20g of 1,6-hexanediol diacrylate was added to the mixture, the stirring speed was increased to 300 rpm, and the mixture was stirred for 30 min to fully mix the 1,6-hexanediol diacrylate with isooctyl acrylate and polyurethane to obtain a mixed system;

[0046] S33. Add 80g of bisphenol A epoxy resin and 20g of bisphenol F epoxy resin to the mixed system, keep stirring to uniformly disperse the bisphenol A epoxy resin and bisphenol F epoxy resin in the mixed system, and stir for 30min; add 5g of azobisisobutyronitrile to the mixed system, and stir at 300rpm for 3h to obtain a glue solution.

[0047] Example 3

[0048] This embodiment provides a method for preparing ultra-high molecular weight polyethylene fiber, comprising the following steps:

[0049] Step 1: adding 1000 g of ultra-high molecular weight polyethylene powder with a weight average molecular weight of 5 million to 5000 g of decalin to dissolve and obtain a spinning solution;

[0050] Step 2: Add the spinning solution into a twin-screw extruder and extrude at 130° C. to obtain a gel-like spinning solution;

[0051] Step 3: The spinning solution is filtered and extruded through a spinneret with a spinneret diameter of 0.05 mm to obtain fiber filaments. The fiber filaments are extracted, washed with clean water multiple times, dried at 60°C, stretched 120% at 150°C, and heat-set at 160°C to obtain fiber filaments. The fiber filaments are immersed in a dipping tank filled with glue for 3 hours, washed, and dried to obtain ultra-high molecular weight polyethylene fibers.

[0052] The preparation method of the glue solution includes:

[0053] S31, 400g of isooctyl acrylate was poured into a container, and the isooctyl acrylate was kept in a uniform flow state at a speed of 200rpm; 50g of polyurethane was slowly added to the isooctyl acrylate, and stirring was continued to fully disperse and dissolve the polyurethane in the isooctyl acrylate, and the stirring time was 30min to obtain a mixed solution;

[0054] S32, 10g of 1,6-hexanediol diacrylate was added to the mixture, the stirring speed was increased to 300 rpm, and the mixture was stirred for 30 min to fully mix the 1,6-hexanediol diacrylate with isooctyl acrylate and polyurethane to obtain a mixed system;

[0055] S33. Add 100 g of bisphenol A epoxy resin and 10 g of bisphenol F epoxy resin to the mixed system, keep stirring until the bisphenol A epoxy resin and bisphenol F epoxy resin are evenly dispersed in the mixed system, and stir for 30 min; add 6 g of azobisisobutyronitrile to the mixed system, and stir at 300 rpm for 3 h to obtain a glue solution.

[0056] Example 4

[0057] This embodiment provides a method for preparing ultra-high molecular weight polyethylene fiber. The difference from Example 1 is that in step 2, 30 g of modified nano-alumina / carbon nanotube composite powder is added to a twin-screw extruder and co-extruded with the spinning solution. The methods and process parameters of the remaining steps of this embodiment are the same as those of Example 1. The method for preparing the modified nano-alumina / carbon nanotube composite powder includes:

[0058] S1. Disperse 5 g of carbon nanotubes with a diameter of 10 to 20 nm in 250 mL of 1 mol / L sodium hydroxide solution, heat to 80° C., keep warm for 3 h, cool and filter, and wash the carbon nanotubes with deionized water until neutral to obtain alkaline carbon nanotubes; disperse 5 g of the alkaline carbon nanotubes in 250 ml of anhydrous ethanol, add 0.5 g of KH550 silane coupling agent, and ultrasonically treat at 60° C. for 2 h at an ultrasonic frequency of 40 kHz to obtain a carbon nanotube dispersion;

[0059] S2. Add 20 g of aluminum isopropoxide and 10 mL of 0.1 M ammonia solution to the carbon nanotube dispersion, and disperse under ultrasonication at 40 kHz for 2 h at 60° C. to obtain a reaction system; then dropwise add 7.5 mL of deionized water to the reaction system, and stir at 80° C. for 4 h to form an AlOOH-CNTs composite sol;

[0060] S3, AlOOH-CNTs composite sol was freeze-dried at -25 ° C for 3 h, then heated to 300 ° C at a rate of 5 ° C / min and kept warm for 1 h; then heated to 600 ° C at a rate of 10 ° C / min and kept warm for 2 h; finally, heated to 900 ° C at a rate of 20 ° C / min, kept warm for 30 min, and cooled to room temperature to obtain modified nano-alumina / carbon nanotube composite powder.

[0061] Example 5

[0062] This embodiment provides a method for preparing ultra-high molecular weight polyethylene fiber. The difference from Example 1 is that in step 2, 40 g of modified nano-alumina / carbon nanotube composite powder is added to a twin-screw extruder and co-extruded with the spinning solution. The methods and process parameters of the remaining steps of this embodiment are the same as those of Example 1. The method for preparing modified nano-alumina / carbon nanotube composite powder includes:

[0063] S1. Disperse 5 g of carbon nanotubes with a diameter of 10 to 20 nm in 250 mL of a 2 mol / L sodium hydroxide solution, raise the temperature to 60° C., keep warm for 3 h, cool and filter, and then wash the carbon nanotubes with deionized water until neutral to obtain alkaline carbon nanotubes; disperse 5 g of the alkaline carbon nanotubes in 250 mL of anhydrous ethanol, add 1.5 g of KH550 silane coupling agent, and ultrasonically treat at 60° C. for 4 h at an ultrasonic frequency of 40 kHz to obtain a carbon nanotube dispersion;

[0064] S2. Add 40 g of aluminum isopropoxide and 15 mL of 0.1 M ammonia solution to the carbon nanotube dispersion, and disperse under ultrasonication at 40 kHz for 1 h at 60° C. to obtain a reaction system; then dropwise add 15 mL of deionized water to the reaction system, and stir at 80° C. for 5 h to form an AlOOH-CNTs composite sol;

[0065] S3, AlOOH-CNTs composite sol was freeze-dried at -25 ° C for 3 h, then heated to 300 ° C at a rate of 5 ° C / min and kept warm for 1 h; then heated to 600 ° C at a rate of 10 ° C / min and kept warm for 2 h; finally, heated to 900 ° C at a rate of 20 ° C / min, kept warm for 30 min, and cooled to room temperature to obtain modified nano-alumina / carbon nanotube composite powder.

[0066] Example 6

[0067] This embodiment provides a method for preparing ultra-high molecular weight polyethylene fiber. The difference from Example 1 is that in step 2, 30 g of modified nano-alumina / carbon nanotube composite powder is added to a twin-screw extruder and co-extruded with the spinning solution. The methods and process parameters of the remaining steps of this embodiment are the same as those of Example 1. The method for preparing modified nano-alumina / carbon nanotube composite powder includes:

[0068] S1. Disperse 5 g of carbon nanotubes with a diameter of 10 to 20 nm in 250 mL of a 2 mol / L sodium hydroxide solution, heat to 80° C., keep warm for 3 h, cool and filter, and wash the carbon nanotubes with deionized water until neutral to obtain alkaline carbon nanotubes; disperse 5 g of the alkaline carbon nanotubes in 250 mL of anhydrous ethanol, add 2 g of KH550 silane coupling agent, and ultrasonically treat at 60° C. for 4 h at an ultrasonic frequency of 40 kHz to obtain a carbon nanotube dispersion;

[0069] S2. Add 60 g of aluminum isopropoxide and 20 mL of 0.1 M ammonia solution to the carbon nanotube dispersion, and disperse the mixture under ultrasonication at 40 kHz for 2 h at 60° C. to obtain a reaction system; then dropwise add 22.5 mL of deionized water to the reaction system, and stir at 90° C. for 6 h to form an AlOOH-CNTs composite sol;

[0070] S3, AlOOH-CNTs composite sol was freeze-dried at -25 ° C for 3 h, then heated to 300 ° C at a rate of 5 ° C / min and kept warm for 1 h; then heated to 600 ° C at a rate of 10 ° C / min and kept warm for 2 h; finally, heated to 900 ° C at a rate of 20 ° C / min, kept warm for 30 min, and cooled to room temperature to obtain modified nano-alumina / carbon nanotube composite powder.

[0071] Comparative Example 1

[0072] This comparative example provides a method for preparing ultra-high molecular weight polyethylene fiber. The difference from Example 1 is that in step three, after heat setting to obtain fiber filaments, the fiber filaments are not immersed in a dipping tank filled with glue, and the heat-set fiber filaments are directly cooled to obtain polyethylene fibers. The methods and process parameters of the remaining steps of this comparative example are the same as those in Example 1.

[0073] Comparative Example 2

[0074] This comparative example provides a method for preparing ultra-high molecular weight polyethylene fibers. Compared with Example 1, in step 2, 10 g of carbon nanotubes with a diameter of 10 to 20 nm and 20 g of nano-alumina powder are added to a twin-screw extruder and co-extruded with the spinning solution. The remaining steps and process parameters of this comparative example are the same as those of Example 1. The method for preparing nano-alumina in this comparative example includes:

[0075] S1. Add 20 g of aluminum isopropoxide and 10 mL of 0.1 M ammonia solution to 250 mL of anhydrous ethanol, and disperse under ultrasonication at 40 kHz for 2 h at 60°C to obtain a reaction system; then dropwise add 7.5 mL of deionized water to the reaction system, and stir at a constant temperature of 80°C for 4 h to form a sol;

[0076] S2. After freeze-drying the sol at -25°C for 3 hours, heat it to 300°C at a rate of 5°C / min and keep it warm for 1 hour; then heat it to 600°C at a rate of 10°C / min and keep it warm for 2 hours; finally heat it to 900°C at a rate of 20°C / min, keep it warm for 30 minutes, and cool it to room temperature to obtain nano alumina powder.

[0077] Comparative Example 3

[0078] This comparative example provides a method for preparing ultra-high molecular weight polyethylene fiber. Compared with Example 1, in step 2, 30 g of carbon nanotubes with a diameter of 10 to 20 nm are added to the twin-screw extruder and co-extruded with the spinning solution. The methods and process parameters of the remaining steps of this comparative example are the same as those in Example 1.

[0079] Comparative Example 4

[0080] This comparative example provides a method for preparing ultra-high molecular weight polyethylene fiber. Compared with Example 1, in step 2, 30 g of nano-alumina powder is added to the twin-screw extruder and co-extruded with the spinning solution. The methods and process parameters of the remaining steps of this comparative example are the same as those of Example 1. The preparation method of nano-alumina in this comparative example includes:

[0081] S1. Add 20 g of aluminum isopropoxide and 10 mL of 0.1 M ammonia solution to 250 mL of anhydrous ethanol, and disperse under ultrasonication at 40 kHz for 2 h at 60°C to obtain a reaction system; then dropwise add 7.5 mL of deionized water to the reaction system, and stir at a constant temperature of 80°C for 4 h to form a sol;

[0082] S2. After freeze-drying the sol at -25°C for 3 hours, heat it to 300°C at a rate of 5°C / min and keep it warm for 1 hour; then heat it to 600°C at a rate of 10°C / min and keep it warm for 2 hours; finally heat it to 900°C at a rate of 20°C / min, keep it warm for 30 minutes, and cool it to room temperature to obtain nano alumina powder.

[0083] The wear resistance, breaking strength, elongation at break and elastic modulus of the polyethylene fibers prepared in Examples 1 to 6 and Comparative Examples 1 to 4 were respectively measured to obtain Table 1; wherein, the wear resistance test referred to FZ / T 50025-2014 "Test Method for Abrasion Resistance of Ultra-High Molecular Weight Polyethylene Filament" and JIS L1095-2010 "Test Method for Ordinary Yarns"; the breaking strength, elongation at break and elastic modulus were determined according to GB / T 19975-2005 "Test Method for Tensile Properties of High-Reinforced Filament", and the test was performed using an INSTRON 34SC-2 electronic tensile testing machine.

[0084] Table 1 Performance data test results of polyethylene fibers of various embodiments and comparative examples

[0085]

[0086]

[0087] As can be seen from the above table, the high-strength wear-resistant polyethylene fibers prepared in Examples 4 to 6 have more wear times, greater breaking strength, elongation at break and elastic modulus, indicating that after the fiber filaments are dipped in glue and the modified nano-alumina / carbon nanotube composite powder is added to the spinning solution, the wear resistance and strength of the prepared ultra-high molecular weight polyethylene fibers are significantly improved.

[0088] The number of devices and processing scales described here are used to simplify the description of the present invention. Applications, modifications and variations of the present invention will be obvious to those skilled in the art.

[0089] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and examples shown and described herein.

Claims

1. A method for preparing ultra-high molecular weight polyethylene fiber, characterized in that: The following steps are involved: Step 1: adding ultra-high molecular weight polyethylene powder into a solvent and dissolving it to obtain a spinning solution; Step 2: Add the spinning solution into a twin-screw extruder, add the modified nano-alumina / carbon nanotube composite powder into the twin-screw extruder, wherein the modified nano-alumina / carbon nanotube composite powder accounts for 2-5% of the mass of the polyethylene powder, and blend and extrude to obtain a spinning solution; The preparation method of modified nano-alumina / carbon nanotube composite powder comprises: S1. Dispersing carbon nanotubes with a diameter of 10-20 nm in a 1-2 mol / L sodium hydroxide solution, heating to 60-80° C., keeping warm for 1-3 hours, cooling and filtering, and washing the carbon nanotubes with deionized water until neutral to obtain alkaline carbon nanotubes; dispersing the alkaline carbon nanotubes in anhydrous ethanol, adding KH550 silane coupling agent, and ultrasonically treating at 60° C. for 2-4 hours at an ultrasonic frequency of 40 kHz to obtain a carbon nanotube dispersion; S2. Add aluminum isopropoxide and 0.1 M ammonia solution to the carbon nanotube dispersion, and disperse the mixture by ultrasonication at 40-55 kHz at 60°C for 1-2 hours to obtain a reaction system; add deionized water dropwise to the reaction system, and stir the mixture at a constant temperature of 70-90°C for 4-8 hours to form an AlOOH-CNTs composite sol; S3, freeze-drying the AlOOH-CNTs composite sol and then calcining it in three stages to obtain modified nano-alumina / carbon nanotube composite powder; Step 3: Filter the spinning solution, extrude it through a spinneret to obtain fiber filaments, extract the fiber filaments, wash, dry, stretch, heat-set, and then immerse them in a glue solution. After taking them out, wash and dry them to obtain ultra-high molecular weight polyethylene fibers; The glue solution comprises, by weight: 20 to 40 parts of isooctyl acrylate, 5 to 20 parts of polyurethane, 1 to 5 parts of 1,6-hexanediol diacrylate, 5 to 10 parts of bisphenol A epoxy resin, and 1 to 5 parts of bisphenol F epoxy resin; The preparation method of the glue solution comprises: S31, pouring isooctyl acrylate into a container, and rotating at a speed of 100-200 rpm to make the isooctyl acrylate in a uniform flow state; slowly adding polyurethane to the isooctyl acrylate, and continuing to stir, so that the polyurethane is fully dispersed and dissolved in the isooctyl acrylate, and the stirring time is 15-30 min to obtain a mixed solution; S32, adding 1,6-hexanediol diacrylate to the mixed solution, increasing the stirring speed to 300-500 rpm, and stirring for 10-30 minutes to obtain a mixed system; S33. Add bisphenol A epoxy resin and bisphenol F epoxy resin to the mixed system, keep stirring for 20 to 30 minutes; add 0.5 to 2 wt% azobisisobutyronitrile to the mixed system, stir at 300 to 500 rpm for 1 to 3 hours to obtain a glue solution.

2. The method for preparing ultra-high molecular weight polyethylene fiber according to claim 1, wherein: In the step 1, the weight average molecular weight of the ultra-high molecular weight polyethylene powder is 3 million to 10 million.

3. The method for preparing ultra-high molecular weight polyethylene fiber according to claim 1, wherein: In the step 1, the solvent is decalin, white oil or paraffin oil, and the mass percentage of the ultra-high molecular weight polyethylene powder to the solvent is 10% to 20%.

4. The method for preparing ultra-high molecular weight polyethylene fiber according to claim 1, wherein: In the step 2, the extrusion temperature of the twin-screw extruder is 130-180°C.

5. The method for preparing ultra-high molecular weight polyethylene fiber according to claim 1, wherein: In the step 3, the spinneret has a spinneret diameter of 0.05 to 0.5 mm.

6. The method for preparing ultra-high molecular weight polyethylene fiber according to claim 1, wherein: In S1, the ratio of carbon nanotubes to sodium hydroxide solution is 1-5 g:250 mL; the ratio of alkalized carbon nanotubes, anhydrous ethanol, and KH550 silane coupling agent is 1-5 g:200-500 mL:0.1-2 g; and in S2, the ratio of alkalized carbon nanotubes, aluminum isopropoxide, ammonia solution, and deionized water is 1-5 g:20-60 g:10-20 mL:7-25 mL.

7. The method for preparing ultra-high molecular weight polyethylene fiber according to claim 1, wherein: In S3, the three-stage calcination specifically includes: heating to 300-500°C at a rate of 5°C / min and keeping warm for 1 hour; then heating to 600-700°C at a rate of 10°C / min and keeping warm for 2 hours; finally heating to 800-900°C at a rate of 20°C / min, keeping warm for 20-30 minutes, and cooling to room temperature to obtain modified nano-alumina / carbon nanotube composite powder.

Images