CN104746165A - Ultra-high molecular weight polyethylene porous fiber and preparation method thereof - Google Patents

Abstract

The invention provides an ultra-high molecular weight polyethylene porous fiber, the porosity of the ultra-high molecular weight polyethylene porous fiber is 23.60%-58.99%. Compared with the prior art, the ultra-high molecular weight polyethylene porous fiber provided by the invention has a porous structure with an ultra-high specific surface area, and has excellent adsorption performance. Experimental results show that the specific surface area of the ultra-high molecular weight polyethylene porous fiber provided by the invention is 5m ² /g～45m ² /g; at the same time, the ultra-high molecular weight polyethylene porous fiber provided by the invention has high-strength and high-modulus mechanical properties, and the experimental results show that the stretching of the ultra-high molecular weight polyethylene porous fiber provided by the invention The strength is 0.91GPa～1.67GPa, and the modulus is 7.21GPa～15.3GPa.

Description

A kind of ultrahigh molecular weight polyethylene porous fiber and its preparation method

technical field

The invention relates to the technical field of polymer adsorption materials, and more specifically relates to an ultrahigh molecular weight polyethylene porous fiber and a preparation method thereof.

Background technique

Polymer adsorption material is a new type of functional material. Because of its large pore size and specific surface area, abundant raw material sources, strong oxidation resistance, and easy regeneration, it is widely used in chemical, medical, agricultural, and national defense. field.

In the field of environmental protection, the pollution caused by wastewater containing a large amount of harmful chemical substances is one of the most serious environmental problems faced by human beings. However, the traditional sewage treatment methods have been powerless to the wastewater containing traces or traces of harmful compounds, and it has become a goal that people pursue to find cost-effective sewage treatment methods to remove these chemicals. Among them, activated carbon has made an important contribution in treating sewage, but its low mechanical strength and high regeneration cost limit its use. The polymer adsorption material has the characteristics of large specific surface area, easy regeneration, and adjustable resin and pore structure. It gradually replaces activated carbon in wastewater treatment, and can be targeted according to the different components in the treated wastewater. The adsorption resin is selected, and acrylonitrile, acrylic acid, etc. are grafted onto the polymer main chain to form amidoxime and acrylamide copolymers, thereby effectively adsorbing heavy metals in wastewater.

With the development of the chemical industry, the types and quantities of hazardous chemicals have also increased significantly. The flammability, corrosion and toxicity of many hazardous chemicals determine the frequency and severity of accidents, and some of them will cause acute or chronic accidents. Poisoning or even death, and the pollution of the ecological environment is very serious. Because liquid hazardous chemical leakage accidents are highly harmful, sudden, and difficult to deal with, it is difficult to take scientific and reasonable emergency response measures immediately after the accident occurs according to the nature of hazardous chemicals. At present, the adsorption method is still the most commonly used method to deal with leakage accidents of liquid hazardous chemicals, especially for leakage accidents of insoluble water-based hazardous chemicals, which is more rapid and effective. Therefore, polymer adsorption materials have important development prospects in the treatment of hazardous chemicals.

More importantly, polymer adsorption materials have great application prospects in extracting uranium from seawater. The energy crisis is a huge challenge facing the world today. With the sharp rise in human energy demand, carbon-based energy will be exhausted in the foreseeable future. Vigorously developing nuclear energy is the key to solving the energy crisis of mankind, and uranium is the most important nuclear fuel. At present, the limited uranium mines on land will be gradually depleted in the next hundred years, but the total amount of uranium elements in the ocean is extremely rich (4.5 billion tons); enrichment and extraction of uranium elements in seawater is an important way to solve the uranium crisis. Its research has broad prospects. But the concentration of uranium in seawater is only 3 to 4 parts per billion, so researching a cost-effective method for extracting uranium from seawater is a huge challenge. At present, the adsorption method is one of the most effective methods, and the traditional adsorbent is an inorganic metal oxide. Since the specific gravity of the inorganic adsorbent is faster than that of the seawater, a fluidized bed system is required, and the adsorbent is placed on the upper layer of the fluidized bed. Use a pump to pump seawater into the lower layer of the fluidized bed at high pressure, and then turn it over to the upper layer, so as to stir the deposited adsorbent, so that the adsorbent can fully contact with seawater. However, the cost of this method is too high, and the strength of the adsorbent is not high, and the reuse rate is very low. Using radiation to induce grafted polymers, a polymer adsorption material is obtained. Its density is similar to that of seawater, and its strength is significantly improved. It cleverly uses the disturbance of tides or waves without external stirring, and the material reuse rate is very high.

In addition, the superabsorbent resin in the polymer adsorption material has unique water absorption and water retention capabilities, and can quickly absorb liquid water that is hundreds or even a thousand times heavier than itself, and the absorbed water is not easy to overflow under high pressure. In view of these advantages, in recent years Polymer water-absorbing resin has become an important functional material, and is widely used in medicine and health, construction, agriculture, forestry and gardening, fresh-keeping transportation, soil water fixation in arid areas, etc.

At present, ultra-high molecular weight polyethylene is a flexible polymer with a main chain structure of -(-CH ₂ -CH ₂ -) _n -, and its molecular microstructure is extremely regular, which endows the material with high strength, high modulus and chemical inertness. With excellent performance, the ultra-high molecular weight polyethylene fiber prepared from it is very suitable as a matrix material for polymer adsorption materials. However, the traditional ultra-high molecular weight polyethylene fiber has a low specific surface area and limited adsorption capacity.

Contents of the invention

In view of this, the object of the present invention is to provide a porous ultra-high molecular weight polyethylene fiber and a preparation method thereof. The porous ultra-high molecular weight polyethylene fiber provided by the present invention has a porous structure with an ultra-high specific surface area and has high strength and high modulus. Quantitative mechanical properties.

The invention provides an ultra-high molecular weight polyethylene porous fiber, the porosity of the ultra-high molecular weight polyethylene porous fiber is 23.60%-58.99%.

The present invention also provides a preparation method of ultra-high molecular weight polyethylene porous fiber, comprising the following steps:

a) mixing ultra-high molecular weight polyethylene powder, a solvent, an antioxidant and a lubricant, and heating to obtain a flocculated spinning solution;

b) spinning the flocculated spinning solution to obtain jelly filaments;

c) performing primary stretching, fixed-length extraction and drying, and secondary stretching on the jelly filaments in sequence to obtain ultra-high molecular weight polyethylene porous fibers;

The temperature of the primary stretching is 20°C-30°C, the strain rate is 0.1s ^-1 -1.2s ^-1 , and the stretching ratio is 3-12;

The temperature of the secondary stretching is 100°C-130°C, the strain rate is 0.1s ^-1 -1.5s ^-1 , and the stretching ratio is 1.5-6.0.

Preferably, the weight average molecular weight of the ultra-high molecular weight polyethylene powder in step a) is 2.0×10 ⁶ to 5.5×10 ⁶ , the molecular weight distribution is <3.0, and the particle size is 100 mesh to 130 mesh.

Preferably, the solvent in step a) includes one or more of white oil, decahydronaphthalene and kerosene.

Preferably, the mass ratio of the ultra-high molecular weight polyethylene powder and the solvent in step a) is (3-15): (85-97).

Preferably, the antioxidant in step a) includes one or more of BHT antioxidant, Irgafos-168 antioxidant and composite antioxidant.

Preferably, the lubricant described in step a) is aluminum stearate.

Preferably, the heating temperature in step a) is 100°C-125°C, and the heating time is 1h-3h.

Preferably, the step b) is specifically:

The flocculated spinning solution is extruded, spun, sprayed and cooled in sequence to obtain jelly filaments.

Preferably, the extractant used in the extraction process in step c) includes one or more of 103 white oil extractant, n-hexane, gasoline and tetrahydrocarbon.

The invention provides an ultra-high molecular weight polyethylene porous fiber, the porosity of the ultra-high molecular weight polyethylene porous fiber is 23.60%-58.99%. The present invention also provides a preparation method of ultra-high molecular weight polyethylene porous fiber, comprising the following steps: a) mixing ultra-high molecular weight polyethylene powder, solvent, antioxidant and lubricant, and heating to obtain flocculated spinning solution; b) spinning the flocculated spinning solution to obtain jelly filaments; c) performing primary stretching, fixed-length extraction and drying, and secondary stretching on the jelly filaments sequentially to obtain ultra-high Molecular weight polyethylene porous fiber; the temperature of the primary stretching is 20°C to 30°C, the strain rate is 0.1s ^-1 to 1.2s ^-1 , and the stretching ratio is 3 to 12; the temperature of the secondary stretching is 100°C to 130°C, the strain rate is 0.1s ^-1 to 1.5s ^-1 , and the draw ratio is 1.5 to 6.0. Compared with the prior art, the ultra-high molecular weight polyethylene porous fiber provided by the invention has a porous structure with an ultra-high specific surface area, and has excellent adsorption performance. Experimental results show that the specific surface area of the ultra-high molecular weight polyethylene porous fiber provided by the invention is 5m ² /g～45m ² /g; at the same time, the ultra-high molecular weight polyethylene porous fiber provided by the invention has high-strength and high-modulus mechanical properties, and the experimental results show that the stretching of the ultra-high molecular weight polyethylene porous fiber provided by the invention The strength is 0.91GPa～1.67GPa, and the modulus is 7.21GPa～15.3GPa.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only It is an embodiment of the present invention, and those skilled in the art can also obtain other drawings according to the provided drawings without creative work.

Fig. 1 is the schematic diagram of the jelly silk prepared by the embodiment of the present invention 1;

Fig. 2 is the schematic diagram after the jelly silk prepared in Example 1 of the present invention is wound;

Fig. 3 is the scanning electron micrograph of the cross-sectional morphology of the jelly filament provided in Example 1 of the present invention;

Figure 4 is a scanning electron micrograph of the cross-sectional morphology of the ultra-high molecular weight polyethylene porous fiber provided by Example 1 of the present invention;

Figure 5 is a scanning electron micrograph of the surface morphology of the ultra-high molecular weight polyethylene porous fiber provided by Example 1 of the present invention;

Fig. 6 is the variation curve of the product tensile strength with temperature of different draw ratios prepared in Example 1 and Examples 6-16;

Fig. 7 is the variation curve of the product modulus with temperature of different stretch ratios prepared in Example 1 and Examples 6-16.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The invention provides an ultra-high molecular weight polyethylene porous fiber, the porosity of the ultra-high molecular weight polyethylene porous fiber is 23.60%-58.99%.

In the present invention, the section of the ultra-high molecular weight polyethylene porous fiber has a porous structure and a suitable specific surface area, so that the material has excellent adsorption performance while maintaining the structural regularity and density of the ultra-high molecular weight polyethylene, Its weight-average molecular weight is not less than 2.0×10 ⁶ and the molecular weight distribution is within 3.0, so that the material has high-strength and high-modulus mechanical properties. In the present invention, the porosity of the ultra-high molecular weight polyethylene porous fiber is 23.60%-58.99%, preferably 35%-50%.

The ultra-high molecular weight polyethylene porous fiber provided by the invention adopts a suitable preparation process to retain the porous structure of the intermediate product jelly silk, so that the product has a porous structure with an ultra-high specific surface area and excellent adsorption performance. At the same time, the ultra-high molecular weight polyethylene fiber provided by the invention High-molecular-weight polyethylene porous fiber is prepared from ultra-high-molecular-weight polyethylene powder with a weight-average molecular weight of not less than 2.0×10 ⁶ , a molecular weight distribution within 3.0, and a uniform particle size distribution. It has high-strength and high-modulus mechanical properties. Therefore, it is very suitable for use as a matrix material for polymer adsorption materials. Through functional grafting, functional groups with selective adsorption are grafted on the main chain to endow the material with selective adsorption performance on the basis of high adsorption performance.

The present invention also provides a preparation method of ultra-high molecular weight polyethylene porous fiber, comprising the following steps:

a) mixing ultra-high molecular weight polyethylene powder, a solvent, an antioxidant and a lubricant, and heating to obtain a flocculated spinning solution;

b) spinning the flocculated spinning solution to obtain jelly filaments;

c) performing primary stretching, fixed-length extraction and drying, and secondary stretching on the jelly filaments in sequence to obtain ultra-high molecular weight polyethylene porous fibers;

The temperature of the primary stretching is 20°C-30°C, the strain rate is 0.1s ^-1 -1.2s ^-1 , and the stretching ratio is 3-12;

The temperature of the secondary stretching is 100°C-130°C, the strain rate is 0.1s ^-1 -1.5s ^-1 , and the stretching ratio is 1.5-6.0.

In the present invention, ultrahigh molecular weight polyethylene powder, solvent, antioxidant and lubricant are mixed and heated to obtain a flocculated spinning solution. In the present invention, the weight average molecular weight of the ultra-high molecular weight polyethylene powder is preferably 2.0×10 ⁶ to 5.5×10 ⁶ , more preferably 4.5×10 ⁶ ; the molecular weight distribution of the ultra-high molecular weight polyethylene powder is as far as possible Narrow, preferably less than 3.0; the particle size of the ultra-high molecular weight polyethylene powder is preferably 100 mesh to 130 mesh, more preferably 120 mesh. In the present invention, there is no special limitation on the source of the ultra-high molecular weight polyethylene powder, and commercially available products well known to those skilled in the art can be used.

In the present invention, the solvent preferably includes one or more of white oil, decalin and kerosene, more preferably white oil. The present invention has no special limitation on the source of the solvent, and the above-mentioned white oil, decahydronaphthalene and kerosene known to those skilled in the art are commercially available. In the present invention, the function of the solvent is to mix with the ultra-high molecular weight polyethylene powder to form a dilute solution; the mass ratio of the ultra-high molecular weight polyethylene powder to the solvent is preferably (3～15):(85～97), More preferably 5:95.

In the present invention, the antioxidant preferably includes one or more of BHT antioxidant, Irgafos-168 antioxidant and composite antioxidant, more preferably BHT antioxidant. The present invention has no special limitation on the source of the antioxidant, and the above-mentioned BHT antioxidant, Irgafos-168 antioxidant and composite antioxidant known to those skilled in the art are commercially available. In the present invention, the function of the antioxidant is to prevent high-temperature oxidation of the flocculated spinning solution; the mass ratio of the antioxidant to ultra-high molecular weight polyethylene powder is preferably (0.1-0.8): 100, more preferably It is 0.5:100.

In the present invention, the lubricant is preferably aluminum stearate. The present invention has no special limitation on the source of the aluminum stearate, the purpose is to reduce the viscosity of the flocculated spinning solution during the preparation process. In the present invention, the mass ratio of the lubricant to the ultra-high molecular weight polyethylene powder is preferably (0.1-0.8):100, more preferably 0.5:100.

In the present invention, UHMWPE powder, solvent, antioxidant and lubricant are mixed and heated. The present invention has no special restrictions on the heating equipment, preferably a swelling tank; in the present invention, the heating process is preferably carried out under stirring conditions, the purpose is to make ultra-high molecular weight polyethylene powder, solvent, antioxidant and The lubricant is mixed well. In the present invention, the heating temperature is preferably 100°C-125°C, more preferably 120°C; the heating time is preferably 1h-3h, more preferably 2h. In the present invention, the process of the heating is specifically:

Mix the ultra-high molecular weight polyethylene powder, solvent, antioxidant and lubricant evenly under the condition of stirring, and heat and swell. When the swelling state is flocculated, control the heating temperature. spinning solution.

After obtaining the flocculated spinning solution, the present invention spins the flocculated spinning solution to obtain jelly filaments. Please refer to Fig. 1～3, wherein, Fig. 1 is the schematic diagram of the jelly silk prepared by the embodiment of the present invention 1, Fig. 2 is the schematic diagram of the jelly silk prepared by the embodiment of the present invention 1 after winding, by Fig. 1 and Fig. 2 It can be seen that the axial length of the intermediate product jelly silk prepared in Example 1 of the present invention is large, so that the final product also has the characteristics of large axial length; FIG. As can be seen from FIG. 3, the section of the intermediate product jelly silk prepared in Example 1 of the present invention has a porous structure, which provides a basis for the final product to have a porous structure with an ultra-high specific surface area.

In the present invention, the spinning process is preferably specifically:

The flocculated spinning solution is extruded, spun, sprayed and cooled in sequence to obtain jelly filaments.

In the present invention, the flocculated spinning solution is extruded. The present invention has no special limitation on the extruding equipment, preferably a twin-screw extruder; the temperature of the extrusion process of the twin-screw extruder is preferably 190°C-230°C, and the screw speed is preferably 200rpm-300rpm.

After the extrusion process is completed, the present invention spins the extruded polymer. The present invention has no special restrictions on the spinning equipment, and preferably uses a spinning box; the process of spinning the spinning box realizes extrusion stretching and extrusion by controlling the speed of the metering pump of the spinning box and the speed of the traction roller. Do not stretch.

After completing the spinning process, the present invention spins and cools the spun polymer. The present invention preferably uses a spinneret, and the extruded multi-strand polymer enters the cooling liquid area through a traction device, completes spinning and cooling, and obtains jelly filaments. In the present invention, the distance between the spinneret and the liquid surface of the cooling liquid is preferably 2cm to 5cm; the process of spinning and cooling preferably also includes spraying a surfactant on the polymer fluid extruded from the spinneret, in order to Prevents rebonding of extruded strands of polymer fluid. In the present invention, the surfactant is preferably one or both of sodium dodecylsulfate and sodium dodecylbenzenesulfonate.

After the jelly filaments are obtained, the present invention sequentially performs primary stretching, fixed-length extraction and drying, and secondary stretching on the jelly filaments to obtain ultra-high molecular weight polyethylene porous fibers. In the present invention, the temperature of the primary stretching is 20°C to 30°C, preferably 25°C; the strain rate of the primary stretching is 0.1s ^-1 to 1.2s ^-1 , preferably 1.0s ^{- 1} ; the stretching ratio of the primary stretching is 3-12, preferably 10.

After the primary stretching is completed, the present invention performs fixed-length extraction and drying on the stretched jelly filaments. In the present invention, the fixed-length extraction process is preferably carried out under ultrasonic conditions, in order to remove a large amount of solvent in the jelly silk; the ultrasonic time is preferably 2 minutes to 5 minutes. In the present invention, the extractant used in the fixed-length extraction process preferably includes one or more of 103 white oil extractant, n-hexane, gasoline and tetrahydrocarbon, more preferably 103 white oil extractant. In the present invention, the length-extracted fibers are dried. The present invention has no special limitation on the drying method, the purpose is to volatilize the extractant.

After the length-fixed extraction and drying processes are completed, the present invention performs secondary stretching on the obtained porous fibers. In the present invention, the temperature of the secondary stretching is 100°C to 130°C, preferably 110°C to 120°C; the strain rate of the secondary stretching is 0.1s ^-1 to 1.5s ^-1 , preferably 1.0s ⁻¹ ; the stretching ratio of the secondary stretching is 1.5-6.0, preferably 3-5. The invention controls the stretching conditions and selects the suitable stretching temperature, strain rate and stretching ratio, so as to control the product to retain the jelly filament porous structure and at the same time ensure that the product has high tensile strength and modulus.

The invention provides an ultra-high molecular weight polyethylene porous fiber, the porosity of the ultra-high molecular weight polyethylene porous fiber is 23.60%-58.99%. The present invention also provides a preparation method of ultra-high molecular weight polyethylene porous fiber, comprising the following steps: a) mixing ultra-high molecular weight polyethylene powder, solvent, antioxidant and lubricant, and heating to obtain flocculated spinning solution; b) spinning the flocculated spinning solution to obtain jelly filaments; c) performing primary stretching, fixed-length extraction and drying, and secondary stretching on the jelly filaments sequentially to obtain ultra-high Molecular weight polyethylene porous fiber; the temperature of the primary stretching is 20°C to 30°C, the strain rate is 0.1s ^-1 to 1.2s ^-1 , and the stretching ratio is 3 to 12; the temperature of the secondary stretching is 100°C to 130°C, the strain rate is 0.1s ^-1 to 1.5s ^-1 , and the draw ratio is 1.5 to 6.0. Compared with the prior art, the ultra-high molecular weight polyethylene porous fiber provided by the invention has a porous structure with an ultra-high specific surface area, and has excellent adsorption performance. Experimental results show that the specific surface area of the ultra-high molecular weight polyethylene porous fiber provided by the invention is 5m ² /g～45m ² /g; at the same time, the ultra-high molecular weight polyethylene porous fiber provided by the invention has high-strength and high-modulus mechanical properties, and the experimental results show that the stretching of the ultra-high molecular weight polyethylene porous fiber provided by the invention The strength is 0.91GPa～1.67GPa, and the modulus is 7.21GPa～15.3GPa.

In order to further illustrate the present invention, the following examples are described in detail below. The UHMWPE powder used in the following examples of the present invention is provided by Tecona; the used white oil is provided by Shangyu Zhengyuan Oil Chemical Co., Ltd.; the BHT type antioxidant used is provided by Aladdin Reagent Co., Ltd.; the used hard acid Aluminum was provided by Aladdin Reagent Co., Ltd.; the sodium lauryl sulfate used was provided by Aladdin Reagent Co., Ltd.; the 103 white oil extractant used was provided by Shanghai Hiller Chemical Co., Ltd.

Example 1

(1) 0.395 kg of ultra-high molecular weight polyethylene powder with a weight-average molecular weight of 4.5×10 ⁶ , a molecular weight distribution within 3.0, and a particle size of 120 meshes, 7.5 kg of white oil, 1.97 g of BHT-type antioxidant and 1.97 g of aluminum stearate Mix evenly, heat and stir in the swelling kettle at 120°C for 2 hours, until the polymer mixture is heated and swelled into a flocculated state, control the heating temperature, and after standing, remove the excess white oil in the upper layer to obtain a flocculated spinning solution;

(2) The flocculated spinning solution is extruded through a twin-screw extruder at 200°C and the screw speed is 250rpm, and then spun through a spinning box and extruded from a spinneret to obtain multi-strand polymers. The device enters the cooling liquid area after spraying sodium lauryl sulfate, and is cooled to obtain jelly filaments.

(3) Under the conditions of 25°C, stretching ratio of 10, and strain rate of 1.0s ^-1 , the jelly silk was stretched for one level, and then extracted with 103 white oil extractant under ultrasonic conditions for 4 minutes, dried, and finally Under the conditions of 120℃, stretching ratio of 3 and strain rate of 1.0s ^-1 , two-stage stretching was carried out to obtain ultra-high molecular weight polyethylene porous fibers.

The ultrahigh molecular weight polyethylene porous fiber provided in Example 1 was characterized by a scanning electron microscope. Please refer to Fig. 4 and Fig. 5, wherein Fig. 4 is a scanning electron micrograph of the cross-sectional morphology of the ultra-high molecular weight polyethylene porous fiber provided by Example 1 of the present invention. It can be seen from Fig. 4 that the ultra-high molecular weight polyethylene provided by Example 1 of the present invention The section of polyethylene porous fiber has a porous structure, which greatly increases the specific surface area of the fiber, so that the material has excellent adsorption performance. Figure 5 is a scanning electron microscope image of the surface morphology of the ultra-high molecular weight polyethylene porous fiber provided by Example 1 of the present invention. It can be seen from Figure 5 that the ultra-high molecular weight polyethylene porous fiber provided by Example 1 of the present invention has a regular structure and high density , so that the material has high strength and high modulus mechanical properties.

Test the porosity of the ultra-high molecular weight polyethylene porous fiber prepared in Example 1 of the present invention. The experimental method for measuring the porosity is: first weigh the dry weight _m1 of the fiber, pour an appropriate amount of xylene solvent into the Erlenmeyer flask, and Immerse the fiber in the xylene solvent, and then vacuumize the solvent to fully enter the fiber pores. At this time, a large number of bubbles overflow from the solvent. When there are no more bubbles in the solvent, it means that the pores in the fiber are completely filled with the solvent, and then quickly take it out. Fiber, gently absorb the residual solvent on the surface of the fiber with a filter paper dipped in xylene solvent, and then quickly weigh the weight m ₂ of the fiber. According to the formula (I), the fiber porosity can be obtained. where _ρX and _ρP are the densities of xylene solvent and polyethylene, respectively.

Experimental results show that the porosity of the UHMWPE porous fiber prepared in Example 1 of the present invention is 58.99%, and the specific surface area is 45 m ² /g.

Example 2

The present invention prepares ultra-high molecular weight polyethylene porous fibers according to the technical solution described in Example 1, with the difference that the weight-average molecular weight of the ultra-high molecular weight polyethylene powder used in this example is 2.0×10 ⁶ .

The ultra-high molecular weight polyethylene porous fiber prepared in Example 2 of the present invention has a porosity of 25% and a specific surface area of 5 m ² /g.

Example 3

The present invention prepares ultra-high molecular weight polyethylene porous fibers according to the technical solution described in Example 1, with the difference that the weight-average molecular weight of the ultra-high molecular weight polyethylene powder used in this example is 5.5×10 ⁶ .

The porosity of the ultra-high molecular weight polyethylene porous fiber prepared in Example 3 of the present invention was 55%.

Example 4

The present invention prepares ultra-high molecular weight polyethylene porous fibers according to the technical solution described in Example 1, with the difference that the particle size of the ultra-high molecular weight polyethylene powder used in this example is 100 mesh.

The porosity of the UHMWPE porous fiber prepared in Example 4 of the present invention is 30%.

Example 5

The present invention prepares ultra-high molecular weight polyethylene porous fibers according to the technical solution described in Example 1, with the difference that the particle size of the ultra-high molecular weight polyethylene powder used in this example is 130 mesh.

The porosity of the ultra-high molecular weight polyethylene porous fiber prepared in Example 5 of the present invention is 50%.

Example 6

The present invention prepares ultra ^- high molecular weight polyethylene porous fibers according to the technical solution described in Example 1. The difference is that in this example, the secondary stretch.

Example 7

The present invention prepares ultra ^- high molecular weight polyethylene porous fibers according to the technical solution described in Example 1. The difference is that in this example, the secondary stretch.

Example 8

The present invention prepares ultra ^- high molecular weight polyethylene porous fibers according to the technical solution described in Example 1. The difference is that in this example, the secondary stretch.

Example 9

The present invention prepares ultra ^- high molecular weight polyethylene porous fibers according to the technical solution described in Example 1. The difference is that in this example, the secondary stretch.

Example 10

The present invention prepares ultra ^- high molecular weight polyethylene porous fibers according to the technical solution described in Example 1. The difference is that in this example, the secondary stretch.

Example 11

The present invention prepares ultra ^- high molecular weight polyethylene porous fibers according to the technical solution described in Example 1. The difference is that in this example, the secondary stretch.

Example 12

The present invention prepares ultra ^- high molecular weight polyethylene porous fibers according to the technical solution described in Example 1. The difference is that in this example, the secondary stretch.

Example 13

The present invention prepares ultra ^- high molecular weight polyethylene porous fibers according to the technical solution described in Example 1. The difference is that in this example, the secondary stretch.

Example 14

The present invention prepares ultra ^- high molecular weight polyethylene porous fibers according to the technical solution described in Example 1. The difference is that in this example, the secondary stretch.

Example 15

The present invention prepares ultra ^- high molecular weight polyethylene porous fibers according to the technical solution described in Example 1. The difference is that in this example, the secondary stretch.

Example 16

The present invention prepares ultra ^- high molecular weight polyethylene porous fibers according to the technical solution described in Example 1. The difference is that in this example, the secondary stretch.

The ultra-high molecular weight polyethylene porous fibers prepared in the above-mentioned embodiment 1 and embodiments 6-16 are subjected to tensile strength and modulus tests. The test method is as follows: the two ends of a bundle of fibers are fixed on the clamps of the tensile test device, The initial length of fiber stretching is 4 mm, the stretching speed is 50 μm/min, and the fiber is stretched uniformly until the fiber breaks. The experimental results are shown in Figures 6-7. Among them, Fig. 6 is the variation curve of the tensile strength of products with different stretching ratios prepared in Example 1 and Examples 6-16 with temperature, wherein, A is a product with a secondary stretching ratio of 1.5, and B is a secondary stretching ratio of 1.5. The product with a stretch ratio of 3.0, C is a product with a secondary stretch ratio of 6.0. Figure 7 is the variation curve of the product modulus with temperature of different stretching ratios prepared in Example 1 and Examples 6-16, wherein, A is a product with a secondary stretching ratio of 1.5, and B is a secondary stretching ratio C is a product of 3.0, and C is a product of a secondary draw ratio of 6.0. It can be seen from Figures 6 to 7 that the present invention provides ultra-high molecular weight polyethylene porous fibers with high strength and high modulus mechanical properties.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. An ultra-high molecular weight polyethylene porous fiber, characterized in that the porosity of the ultra-high molecular weight polyethylene porous fiber is 23.60% to 58.99%. 2. A preparation method of ultrahigh molecular weight polyethylene porous fiber, is characterized in that, comprises the following steps: a) mixing ultra-high molecular weight polyethylene powder, a solvent, an antioxidant and a lubricant, and heating to obtain a flocculated spinning solution; b) spinning the flocculated spinning solution to obtain jelly filaments; c) performing primary stretching, fixed-length extraction and drying, and secondary stretching on the jelly filaments in sequence to obtain ultra-high molecular weight polyethylene porous fibers; The temperature of the primary stretching is 20°C-30°C, the strain rate is 0.1s ^-1 -1.2s ^-1 , and the stretching ratio is 3-12; The temperature of the secondary stretching is 100°C-130°C, the strain rate is 0.1s ^-1 -1.5s ^-1 , and the stretching ratio is 1.5-6.0. 3. The preparation method according to claim 2, characterized in that, the weight average molecular weight of the ultra-high molecular weight polyethylene powder in step a) is 2.0×10 ⁶ to 5.5×10 ⁶ , the molecular weight distribution is <3.0, and the particle size is 100 mesh to 130 mesh. 4. The preparation method according to claim 2, characterized in that, the solvent described in step a) comprises one or more of white oil, decahydronaphthalene and kerosene. 5. The preparation method according to claim 2, characterized in that the mass ratio of the ultra-high molecular weight polyethylene powder and the solvent in step a) is (3-15): (85-97). 6. preparation method according to claim 2, is characterized in that, step a) described antioxidant comprises one or more in BHT type antioxidant, Irgafos-168 type antioxidant and composite antioxidant kind. 7. The preparation method according to claim 2, characterized in that, the lubricant described in step a) is aluminum stearate. 8. The preparation method according to claim 2, characterized in that the heating temperature in step a) is 100°C-125°C, and the time is 1h-3h. 9. The preparation method according to claim 2, characterized in that, the step b) is specifically: The flocculated spinning solution is extruded, spun, sprayed and cooled in sequence to obtain jelly filaments. 10. preparation method according to claim 2, is characterized in that, step c) in the extraction process described extraction agent used comprises one or more in 103 white oil extraction agents, normal hexane, gasoline and tetrahydrocarbon .