An ultrahigh molecular weight polyethylene fiber with good high temperature resistance and a preparation method and application thereof

Abstract

The present application relates to the technical field of polyethylene fibers, in particular to a kind of ultra-high molecular weight polyethylene fiber with good high-temperature resistance and its preparation method and application, ultra-high molecular weight polyethylene powder, heat preservation and insulation particles are mixed with white oil, and the gel spinning is carried out by double screw extruder, to obtain organic-inorganic hybrid composite gel fiber;Organic-inorganic hybrid composite gel fiber is immersed in mixed solution and extracted and deoiled, and after drying, hot stretching and ultraviolet irradiation treatment, high-temperature-resistant ultra-high molecular weight polyethylene fiber is prepared;Nanometer heat insulation particles and interfacial modifier are dispersed into solvent, and uniformly mixed to obtain heat insulation sizing agent;Heat insulation sizing agent is coated on the surface of the prepared high-temperature-resistant ultra-high molecular weight polyethylene fiber, to obtain ultra-high molecular weight polyethylene fiber with good high-temperature resistance.The present application solves the problem that the high-temperature resistance is difficult to improve in the prior art by the synergistic modification of organic-inorganic hybrid spinning and chemical crosslinking.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyethylene fibers, in particular to a kind of ultra-high molecular weight polyethylene fiber with good high temperature resistance and its preparation method and application. BACKGROUND

[0002] Ultra-high molecular weight polyethylene (UHMWPE) fiber and its composite materials are widely used in aerospace, deep space probe and other extreme environment fields due to their light weight and high strength. However, such application scenarios are often accompanied by severe temperature fluctuations: for example, the surface temperature of a star body without thermal control measures can fluctuate between -200℃ and 200℃, and with thermal control measures, it still reaches -100℃ to +100℃, and the cabin temperature also fluctuates between -20℃ and +50℃. In such cold and hot alternating environment, UHMWPE fiber and its composite materials are prone to interfacial stress concentration due to the difference in thermal expansion coefficient, leading to material deformation, interlayer peeling and other failure problems. Especially limited by the poor intrinsic high temperature resistance of UHMWPE fiber (melting temperature ≤135℃), the mechanical properties of its composite materials at high temperature are significantly attenuated, which seriously restricts its application in key fields such as spacecraft protection system and thruster components.

[0003] Therefore, in order to further improve the high temperature resistance of ultra-high molecular weight polyethylene fiber and its composite materials in extreme environment, in view of the poor high temperature resistance of ultra-high molecular weight polyethylene fiber, an organic-inorganic hybrid and extraction cross-linking synergistic modification is used to obtain high temperature resistant ultra-high molecular weight polyethylene fiber, and a nano composite thermal barrier coating is coated on the surface of the fiber to enhance the high temperature resistance of the polyethylene fiber.

[0004] In the prior art, in order to improve the high temperature resistance of ultra-high molecular weight polyethylene fiber, methods such as adding inorganic fillers (such as aluminum oxide, silicon carbide) or chemical cross-linking (such as silane coupling agent) are usually used. However, such schemes have obvious defects: (1) the inorganic fillers have poor interfacial compatibility with the polyethylene matrix, which easily leads to a decrease in fiber strength; (2) the improvement of high temperature resistance by chemical cross-linking modification (such as the modification of aluminate coupling agent described in CN119433744A) is limited; (3) traditional modification methods are difficult to simultaneously improve the high temperature resistance and the interfacial bonding force in the fiber composite material. SUMMARY

[0005] The purpose of the present application is to provide a kind of ultra-high molecular weight polyethylene fiber with good high temperature resistance and its preparation method and application, which solves the problem that the high temperature resistance of fiber and the interfacial bonding force of composite material cannot be improved simultaneously in the prior art by synergistic modification of organic-inorganic hybrid spinning and chemical cross-linking.

[0006] To achieve the above-mentioned purpose, the present application provides a preparation method of a kind of ultra-high molecular weight polyethylene fiber with good high temperature resistance, comprising the following steps:

[0007] S1, mixing the ultra-high molecular weight polyethylene powder, heat insulation particles and white oil, and performing gel spinning through a double screw extruder to obtain organic-inorganic hybrid composite gel fibers;

[0008] S2, immersing the organic-inorganic hybrid composite gel fibers of S1 in a mixed solution containing a crosslinking agent, an initiator and an extractant to extract and remove oil, and performing drying, hot stretching and ultraviolet irradiation treatment to obtain high-temperature-resistant ultra-high molecular weight polyethylene fibers;

[0009] S3, dispersing the nano heat insulation particles and an interfacial modifier into a solvent to obtain a heat insulation sizing agent;

[0010] S4, coating the heat insulation sizing agent of S3 on the surface of the high-temperature-resistant ultra-high molecular weight polyethylene fibers obtained in S2, and performing drying and solvent removal treatment to form a heat insulation coating layer, thereby obtaining ultra-high molecular weight polyethylene fibers with good high-temperature resistance.

[0011] Preferably, in S1, the molecular weight of the ultra-high molecular weight polyethylene powder is 300w-600w, and the mass fraction of the ultra-high molecular weight polyethylene powder in the white oil is 6-10%.

[0012] Preferably, in S1, the mass ratio of the heat insulation particles to the ultra-high molecular weight polyethylene powder is 0.5-3:100, and the heat insulation particles include one or more of SiO2 aerogel particles, alumina aerogel particles, titanium dioxide aerogel particles, hollow glass microsphere particles, expanded perlite particles and expanded vermiculite particles.

[0013] More preferably, the heat insulation particles include SiO2 aerogel particles.

[0014] Preferably, in S2, the mass ratio of the crosslinking agent, the initiator and the extractant in the mixed solution is 0.1-3:0.01-0.1:100.

[0015] Preferably, the extractant is dichloromethane.

[0016] Preferably, the crosslinking agent includes one or more of a siloxane coupling agent, a titanate coupling agent, a zirconate coupling agent, an isocyanate, an epoxy-based crosslinking agent, boric acid and derivatives, and an aldehyde-based crosslinking agent.

[0017] More preferably, the crosslinking agent includes a siloxane coupling agent, and the siloxane coupling agent includes vinyltriethoxysilane.

[0018] Preferably, the initiator includes one or more of a phenylacetone derivative, an acyl phosphine oxide, a benzophenone, an aryl diazonium salt, a sulfonium salt, a peroxide, an azo compound, a peroxide, butyllithium, a BF 3- ether complex.

[0019] More preferably, the initiator comprises one of a benzophenone derivative, the benzophenone derivative comprising one of Irgacure 117 (2-hydroxy-2-methyl-1-phenyl-1-propanone), Irgacure 184 (1-hydroxycyclohexyl phenyl ketone), BAPO (bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide).

[0020] Preferably, in S3, the nano thermal insulation particles are SiO2 aerogel particles with micro-nano structure, and the mass fraction of the SiO2 aerogel particles in the thermal insulation sizing agent is 0.1-2%.

[0021] Preferably, in S3, the solvent is dimethyl sulfoxide.

[0022] Preferably, in S3, the interface modifier is an organic small molecule with a multi-arm structure, wherein the arm part is composed of a long alkyl chain, and the general formula of the long alkyl chain is , n≥10, and the mass fraction of the interface modifier in the thermal insulation sizing agent is 0.1-1%.

[0023] Preferably, in S3, the preparation of the interface modifier comprises the following steps:

[0024] 1) Dissolve a polyhydroxyl small molecule organic into an organic solvent A, and stir at 80-100°C until completely dissolved to obtain a transparent solution A with a concentration of 0.1-10wt%;

[0025] 2) Under the condition of introducing a protective gas, add a long alkyl chain-containing compound and a catalyst into the solution A to obtain a solution B, and react at 80-100°C for 1.5-3h to obtain a transparent solution C; the content of the long alkyl chain-containing compound in the solution B is 1-10wt%, and the content of the catalyst is 0.01-0.1wt%;

[0026] 3) Add the solution C dropwise into a precipitant for precipitation, and after washing, centrifugation, filtration and vacuum drying, a white block interface modifier is obtained.

[0027] More preferably, the polyhydroxyl small molecule organic is dipentaerythritol; the organic solvent A is dimethyl sulfoxide, the protective gas is nitrogen; the long alkyl chain-containing compound is octadecyl isocyanate; and the catalyst is dibutyltin dilaurate, and the precipitant is deionized water.

[0028] More preferably, the obtained white block interface modifier is a polyhydroxyl small molecule compound containing an octadecyl long chain.

[0029] The mechanism of the preparation method of the ultra-high molecular weight polyethylene fiber with good high-temperature resistance provided by the application is as follows: by doping heat-insulating nanoparticles in the fiber forming process, adding a silicon-oxygen coupling agent to form a cross-linked structure with polyethylene, and coating a nano heat-insulating coating on the surface of the fiber, the heat conduction in the fiber is inhibited, the melting rate and proportion of the fiber at high temperature are reduced, and the ultra-high molecular weight polyethylene fiber with high-temperature resistance is prepared.

[0030] The application further provides the ultra-high molecular weight polyethylene fiber with good high-temperature resistance, which is prepared by the preparation method of the ultra-high molecular weight polyethylene fiber with good high-temperature resistance.

[0031] The application further provides the application of the ultra-high molecular weight polyethylene fiber with good high-temperature resistance. The ultra-high molecular weight polyethylene fiber with good high-temperature resistance is applied to the fields of bulletproof protection and low-altitude economy.

[0032] The application has the following beneficial effects:

[0033] The application provides the ultra-high molecular weight polyethylene fiber with good high-temperature resistance, the preparation method and the application thereof. The melting temperature of the ultra-high molecular weight polyethylene fiber with high-temperature resistance prepared by the application reaches 200 DEG C, the fiber exhibits good high-temperature resistance and strength retention rate after heat treatment, the interfacial bonding force between the ultra-high molecular weight polyethylene fiber with high-temperature resistance and a resin matrix such as epoxy is greatly improved, and the application field of the ultra-high molecular weight polyethylene fiber is expanded.

[0034] The technical solutions of the application are further described in detail below with reference to the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a surface morphology diagram of the ultra-high molecular weight polyethylene fiber without coating treatment in the comparative example 1 of the application;

[0036] Figure 2 is a surface morphology diagram of the ultra-high molecular weight polyethylene fiber with good high-temperature resistance prepared in the example 2 of the application, Figure 2 a in the surface morphology diagram of the plurality of fibers, Figure 2 b in the surface morphology diagram of the single fiber;

[0037] Figure 3 is a surface element distribution diagram of the ultra-high molecular weight polyethylene fiber with good high-temperature resistance prepared in the example 2 of the application, Figure 3 a in the surface morphology diagram of the ultra-high molecular weight polyethylene fiber with good high-temperature resistance, Figure 3 b in the surface Si element distribution diagram of the ultra-high molecular weight polyethylene fiber with good high-temperature resistance;

[0038] Figure 4 is a fiber morphology diagram of the fiber prepared in Example 2 and Comparative Example 1-2 after heat treatment; Figure 4 a in is a morphology diagram of the ultra-high molecular weight polyethylene fiber without coating a thermal barrier coating in Comparative Example 1 after heat treatment, Figure 4 b in is a morphology diagram of the ultra-high molecular weight polyethylene fiber coated only with an interfacial modifier in Comparative Example 2 after heat treatment, Figure 4 c in is a morphology diagram of the ultra-high molecular weight polyethylene fiber with good high-temperature resistance in Example 2 after heat treatment. DETAILED DESCRIPTION

[0039] The present application is further described below in conjunction with the accompanying drawings and examples. Unless otherwise defined, technical or scientific terms used in the present application should be understood as having the commonly understood meaning in the field of the present application to which the present application pertains. The features mentioned in the present application or the features mentioned in the specific examples mentioned in the present application can be combined in any manner, and these specific examples are only used to illustrate the present application and not to limit the scope of the present application.

[0040] The interfacial modifier used in the present application is prepared by the following steps:

[0041] 1) Dissolve a polyhydroxyl small molecule dipentaerythritol in an organic solvent A (dimethyl sulfoxide) at 80-100°C until completely dissolved to obtain a transparent solution A with a concentration of 0.1-10 wt%.

[0042] 2) Under the protection of protective gas (nitrogen), add long-chain alkyl octadecyl isocyanate and catalyst dibutyltin dilaurate to solution A to obtain solution B, and react at 80-100°C for 1.5-3h to obtain transparent solution C; the content of the long-chain alkyl compound in solution B is 1-10 wt%, and the content of the catalyst is 0.01-0.1 wt%.

[0043] 3) Add solution C dropwise to a precipitant (deionized water) for precipitation, and then wash, centrifuge, filter, and vacuum dry to obtain a white block of the octadecyl long-chain polyhydroxyl small molecule compound interfacial modifier.

[0044] Example 1

[0045] The present application provides an ultra-high molecular weight polyethylene fiber with good high-temperature resistance, and a preparation method thereof, which comprises the following steps:

[0046] S1, mixing the UHMWPE powder with a molecular weight of 300w, SiO2 aerogel particles (0.5% of the mass of the UHMWPE powder) and white oil (10 times the mass of the UHMWPE powder), then putting them into a twin-screw extruder for gel spinning, controlling the temperature of the twin-screw extruder at 65-265℃ (the temperature of each zone is shown in Table 1), cooling in water after spinning, and obtaining organic-inorganic hybrid composite gel fibers.

[0047] S2, after 6 times of cold stretching (room temperature) of the organic-inorganic hybrid composite gel fibers of S1, immersing them in a mixed solution containing vinyltriethoxysilane, photoinitiator 1173 and dichloromethane with a mass ratio of 0.1:0.01:100 for extraction and deoiling, drying, and then sequentially performing primary hot stretching (4 times, 135℃), secondary hot stretching (1.2 times, 138℃), ultraviolet irradiation (45w, 3min), to obtain high-temperature-resistant UHMWPE fibers.

[0048] S3, dissolving dipentaerythritol in dimethyl sulfoxide at 80℃ until completely dissolved, to obtain a transparent solution A with a concentration of 0.1wt%.

[0049] S4, under the condition of protective gas, adding isocyanate octadecyl and catalyst into solution A to obtain solution B, and reacting at 80℃ for 1.5h to obtain transparent solution C. The content of isocyanate octadecyl in solution B is 1wt%, and the content of catalyst is 0.01wt%.

[0050] S5, adding solution C dropwise into a precipitant for precipitation, and after treatment, washing, centrifugation, filtration and vacuum drying, a white block-shaped interfacial modifier is obtained.

[0051] S6, dispersing SiO2 aerogel particles with micro-nano structure and interfacial modifier into dimethyl sulfoxide, ultrasonic oscillation at 75℃ for 30min, and after uniform stirring, obtaining a heat insulation sizing agent; the content of SiO2 aerogel particles is 0.1wt%, and the content of interfacial modifier is 0.1wt%.

[0052] S7, coating the heat insulation sizing agent of S6 on the surface of the high-temperature-resistant UHMWPE fibers prepared in S2, then immersing them into a precipitant (deionized water) to remove organic solvents, and finally removing the precipitant on the surface in a vacuum environment at 80℃ to form a heat insulation coating, obtaining UHMWPE fibers with good high-temperature resistance.

[0053] Table 1 Temperature of each zone of the twin-screw extruder of Example 1 (400r / min)

[0054] ;

[0055] Example 2

[0056] The application provides an ultrahigh molecular weight polyethylene fiber with good high-temperature resistance, and a preparation method thereof.

[0057] S1, mixing ultrahigh molecular weight polyethylene powder with a molecular weight of 500w, SiO2 aerogel particles (2% of the mass of the ultrahigh molecular weight polyethylene powder) and white oil (13 times the mass of the ultrahigh molecular weight polyethylene powder), and then placing the mixture into a double-screw extruder to perform gel spinning, controlling the temperature of the double-screw extruder at 70-270 DEG C (the temperature of each zone is shown in Table 2), and cooling the spun fiber in water to obtain an organic-inorganic hybrid composite gel fiber.

[0058] S2, after 8 times of cold stretching of the organic-inorganic hybrid composite gel fiber of S1, immersing the fiber into a mixed solution containing vinyltriethoxysilane, photoinitiator 1173 and dichloromethane at a mass ratio of 1:0.05:100 to extract and remove oil, and after drying, sequentially performing primary heat stretching (5 times of the ratio, at a temperature of 135 DEG C), secondary heat stretching (1.6 times of the ratio, at a temperature of 138 DEG C), ultraviolet irradiation (45w, 3min) to obtain a high-temperature resistant ultrahigh molecular weight polyethylene fiber.

[0059] S3, dissolving dipentaerythritol in dimethyl sulfoxide at 90 DEG C until completely dissolved to obtain a transparent solution A with a concentration of 5wt%.

[0060] S4, under the condition of passing protective gas, adding isocyanate octadecyl and a catalyst into solution A to obtain solution B, and reacting at 90 DEG C for 2h to obtain transparent solution C. The content of isocyanate octadecyl in solution B is 5wt%, and the content of the catalyst is 0.05wt%.

[0061] S5, dropping solution C into a precipitator to precipitate, and after treatment, washing, centrifugation, filtration and vacuum drying, a white blocky interfacial modifier is obtained.

[0062] S6, dispersing SiO2 aerogel particles with micro-nano structures and the interfacial modifier into dimethyl sulfoxide, ultrasonic oscillation at 75 DEG C for 30min, and after uniform stirring, a heat insulation sizing agent is obtained. The content of the SiO2 aerogel particles is 2.0wt%, and the content of the interfacial modifier is 0.5wt%.

[0063] S7, coating the heat insulation sizing agent of S6 on the surface of the high-temperature resistant ultrahigh molecular weight polyethylene fiber prepared in S2, then immersing into a precipitator (deionized water) to remove organic solvents, and finally removing the precipitator on the surface in a vacuum environment at 80 DEG C to form a heat insulation coating layer, so as to obtain an ultrahigh molecular weight polyethylene fiber with good high-temperature resistance.

[0064] Table 2 Temperature of each zone of the twin-screw extruder in Example 2 (400 r / min)

[0065] ;

[0066] Example 3

[0067] The application provides a kind of ultra-high molecular weight polyethylene fiber with good high temperature resistance, and its preparation method comprises the following steps:

[0068] S1, the ultra-high molecular weight polyethylene powder with molecular weight of 600w, SiO2 Aerogel particles (3% of the mass of the ultra-high molecular weight polyethylene powder) and white oil (16 times the mass of the ultra-high molecular weight polyethylene powder) are mixed, then put into a twin-screw extruder for gel spinning, the temperature of the twin-screw extruder is controlled at 100-275℃ (the temperature of each zone is shown in Table 3), and the organic-inorganic hybrid composite gel fiber is obtained after cooling in water.

[0069] S2, after 12 times of cold stretching of the organic-inorganic hybrid composite gel fiber of S1, it is immersed in a mixed solution containing vinyltriethoxysilane, photoinitiator 1173 and dichloromethane with a mass ratio of 3:0.1:100 for extraction and deoiling, and after drying, it is sequentially subjected to primary hot stretching (6 times, temperature 135℃), secondary hot stretching (2 times, temperature 138℃), ultraviolet irradiation (45w, 3min) to obtain a high-temperature-resistant ultra-high molecular weight polyethylene fiber.

[0070] S3, take dipentenyl alcohol dissolved in dimethyl sulfoxide, stir at 100℃ until completely dissolved, to obtain transparent solution A with a concentration of 10wt%.

[0071] S4, under the condition of protective gas, isocyanate octadecyl ester and catalyst are added into solution A to obtain solution B, and the reaction is carried out at 100℃ for 3h to obtain transparent solution C; the content of isocyanate octadecyl ester in solution B is 10wt%, and the content of catalyst is 0.1wt%.

[0072] S5, solution C is added dropwise into precipitant for precipitation, and after washing, centrifugation, filtration and vacuum drying, white blocky interfacial modifier is obtained.

[0073] S6, SiO2 Aerogel particles with micro-nano structure and interfacial modifier are dispersed into dimethyl sulfoxide, ultrasonic oscillation is carried out at 75℃ for 30min, and after stirring uniformly, heat-insulating sizing agent is obtained, the content of SiO2 Aerogel particles is 3wt%, and the content of interfacial modifier is 1wt%.

[0074] S7, coating the heat insulation sizing agent of S6 on the surface of the high-temperature resistant ultra-high molecular weight polyethylene fiber prepared in S2, then soaking into the precipitator (deionized water), removing the organic solvent, and finally removing the surface precipitator in a vacuum environment at 80°C to form a heat insulation coating, thereby obtaining the ultra-high molecular weight polyethylene fiber with good high-temperature resistance.

[0075] Table 3. Temperature of each zone of the twin-screw extruder in Example 3 (400 r / min)

[0076] ;

[0077] Comparative Example 1

[0078] Based on Example 2, the difference from Example 2 is that only steps S1 and S2 are performed to prepare the high-temperature resistant ultra-high molecular weight polyethylene fiber.

[0079] Comparative Example 2

[0080] Based on Example 2, the difference from Example 2 is that only the interfacial modifier is dispersed into dimethyl sulfoxide in S3 to coat the surface of the high-temperature resistant ultra-high molecular weight polyethylene fiber prepared in S2.

[0081] Characterization experiment

[0082] The products prepared in Example 2 and Comparative Example 1 are characterized by using an electron microscope, and the results are shown in Figures 1 to 2 Comparative Example 1 does not coat the surface of the ultra-high molecular weight polyethylene fiber with a smooth and flat heat insulation coating, and no obvious particles or coating are attached. The high-temperature resistant ultra-high molecular weight polyethylene fiber coated with the heat insulation coating in Example 2 is covered with a uniform granular coating, and presents obvious roughness, which confirms that the heat insulation coating (containing SiO2 aerogel particles) is successfully coated.

[0083] Figure 3 The surface element distribution map of the ultra-high molecular weight polyethylene fiber with good high-temperature resistance prepared in Example 2 of the present application is shown in Figure 3 It can be seen that the SiO2 aerogel particles interact with the interfacial modifier and are uniformly distributed on the surface of the ultra-high molecular weight polyethylene fiber. The interfacial modifier is closely combined with the SiO2 aerogel particles through hydrogen bond interaction, and is combined on the surface of the fiber through similar solubility and mechanical interlocking physical actions, thereby constructing a uniform heat insulation coating.

[0084] Performance test

[0085] The products prepared in Example 2 and Comparative Examples 1-2 are subjected to heat treatment (170°C), the fiber is tightly bound on a bamboo board, and the strength retention rate is measured after heat treatment in an oven at 170°C for 10 min, and the fiber appearance map after heat treatment is observed, and the results are shown in Figure 4As shown, the comparative example 1 is not coated with a thermal barrier coating, and the UHMWPE fiber is obviously deformed or fused after heat treatment, indicating that it is not resistant to high temperature. The comparative example 2 is only coated with an interface modifier, and the UHMWPE fiber is slightly improved in melting degree, but still deformed. The UHMWPE fiber of the example 2 has good high temperature resistance, and is not obviously fused or deformed, and the surface coating is intact.

[0086] As can be seen from the above, the SiO2 aerogel particles in the UHMWPE fiber with good high temperature resistance provided by the application increase the heat transfer resistance of the fiber surface, and the fiber is not fused at 170℃, which can effectively avoid the destruction of the crystal structure in the preparation of the composite material, and the mechanical properties of the UHMWPE are maximally reserved.

[0087] The fiber strength of the UHMWPE fiber with good high temperature resistance prepared by different concentrations of siloxane coupling agent (vinyl triethoxysilane) before and after heat treatment at 180℃ for 5min, wherein the concentration of siloxane coupling agent is 0% as a control group, the concentration of siloxane coupling agent is 1% (example 2) and the concentration of siloxane coupling agent is 3% (example 3) as experimental groups, and the results are shown in Table 4.

[0088] Table 4 Fiber strength data of the UHMWPE fiber with different concentrations of siloxane coupling agent before and after heat treatment at 180℃ for 5min

[0089] ;

[0090] As can be seen from Table 4, when the concentration of siloxane coupling agent is 0%, the strength is obviously decreased after heat treatment, and when the concentration of siloxane coupling agent is 1% and 3%, the strength change is small after heat treatment. It is proved that the siloxane coupling agent can reduce the chain slip by coupling SiO2 aerogel and polyethylene, and can significantly improve the strength retention rate after heat treatment.

[0091] The fiber strength of the UHMWPE fiber with good high temperature resistance prepared by different SiO2 aerogel particle contents before and after heat treatment at 170℃ for 10min, wherein the SiO2 aerogel particle content is 0wt% as a control group, the SiO2 aerogel particle content is 1wt% (example 2) and the SiO2 aerogel particle content is 2wt% (example 3) as experimental groups, and the results are shown in Table 5.

[0092] Table 5 Fiber strength data of the UHMWPE fiber with different aerogel contents before and after heat treatment at 170℃ for 10min

[0093] ;

[0094] As shown in Table 5, when the content of SiO2 aerogel particles is 0wt%, the fiber is fused after heat treatment, and when the content of SiO2 aerogel particles is 2wt% and 3wt%, the strength changes little after heat treatment. It is shown that the introduction of SiO2 aerogel particles can significantly improve the high-temperature resistance of the fiber, and the micro-nano structure can increase the heat transfer resistance and inhibit the melting of the fiber crystallization at high temperature.

[0095] Meanwhile, the heat insulation particle nanocomposite sizing agent for the ultra-high molecular weight polyethylene fiber contains an interface modifier, which has a long alkyl chain composed of methylene and a large amount of hydroxyl groups. The presence of the long alkyl chain is conducive to the combination with the ultra-high molecular weight polyethylene fiber, and the large amount of hydroxyl groups can be combined with polar resins such as epoxy, so as to greatly improve the interfacial shear strength between the ultra-high molecular weight polyethylene fiber and the resins such as epoxy.

[0096] The ultra-high molecular weight polyethylene fiber with good high-temperature resistance provided by the application is prepared by organic-inorganic hybrid spinning, and is crosslinked in the extraction process, so as to effectively improve the high-temperature resistance. The SiO2 aerogel particles increase the heat transfer resistance inside the fiber, and act as rigid crosslinking points, which restrict the movement of the polyethylene molecular chain, so as to effectively improve the high-temperature resistance and creep resistance of the fiber.

[0097] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application but not to limit it, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that: it can still modify or equivalently replace the technical solutions of the present application, and these modifications or equivalent replacements also cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for preparing ultra-high molecular weight polyethylene fiber with good high-temperature resistance, characterized in that, Includes the following steps: S1. Mix ultra-high molecular weight polyethylene powder, thermal insulation granules and white oil, and then perform gel spinning through a twin-screw extruder to obtain organic-inorganic hybrid composite gel fiber. S2. The organic-inorganic hybrid gel fiber of S1 is immersed in a mixed solution containing a crosslinking agent, an initiator and an extractant for extraction and deoiling. After drying, hot stretching and ultraviolet irradiation treatment, high temperature resistant ultra-high molecular weight polyethylene fiber is obtained. The crosslinking agent includes a silicone coupling agent. S3. Disperse the nano-insulating particles and interface modifier in a solvent and mix them evenly to obtain an insulating sizing agent; the nano-insulating particles are SiO2 aerogel particles with micro-nano structures, and the mass fraction of SiO2 aerogel particles in the insulating sizing agent is 0.1-2%; Interface modifiers are organic molecules with multi-arm structures, where the arms are composed of long alkyl chains. The general formula for the long alkyl chains is: For n≥10, the mass fraction of the interface modifier in the thermal insulation sizing agent is 0.1-1%; S4. The heat-insulating sizing agent of S3 is coated onto the surface of the high-temperature resistant ultra-high molecular weight polyethylene fiber obtained in S2. After drying and solvent removal treatment, a heat-insulating coating is formed, which further improves the high-temperature resistance of the fiber and obtains ultra-high molecular weight polyethylene fiber with good high-temperature resistance.

2. The method for preparing ultra-high molecular weight polyethylene fiber with good high-temperature resistance according to claim 1, characterized in that: In S1, the molecular weight of ultra-high molecular weight polyethylene powder is 300w-600w, and its mass fraction in white oil is 6-10%.

3. The method for preparing ultra-high molecular weight polyethylene fiber with good high-temperature resistance according to claim 1, characterized in that: In S1, the mass ratio of thermal insulation particles to ultra-high molecular weight polyethylene powder is 0.5-3:

100. The thermal insulation particles include one or more of the following: SiO2 aerogel particles, alumina aerogel particles, titanium dioxide aerogel particles, hollow glass microsphere particles, expanded perlite particles, and expanded vermiculite particles.

4. The method for preparing ultra-high molecular weight polyethylene fiber with good high-temperature resistance according to claim 1, characterized in that: In S2, the mass ratio of crosslinking agent, initiator and extractant in the mixed solution is 0.1-3:0.01-0.1:

100.

5. The method for preparing ultra-high molecular weight polyethylene fiber with good high-temperature resistance according to claim 1, characterized in that: In S3, the solvent is dimethyl sulfoxide.

6. The method for preparing ultra-high molecular weight polyethylene fiber with good high-temperature resistance according to claim 1, characterized in that: In S3, the preparation of the interface modifier includes the following steps: 1) Dissolve the polyhydroxy small molecule organic compound in organic solvent A, and stir at 80-100℃ until completely dissolved to obtain a transparent solution A with a concentration of 0.1-10wt%; 2) Under the condition of purging with protective gas, the compound containing long alkyl chains and the catalyst are added together to solution A to obtain solution B. The reaction is carried out at 80-100°C for 1.5-3 hours to obtain a transparent solution C. The content of the compound containing long alkyl chains in solution B is 1-10 wt%, and the content of the catalyst is 0.01-0.1 wt%. 3) Add solution C dropwise to the precipitant to precipitate, and after post-treatment washing, centrifugation, filtration, and vacuum drying, a white blocky interface modifier is obtained.

7. A type of ultra-high molecular weight polyethylene fiber with good high-temperature resistance, characterized in that: It is prepared by the method for preparing ultra-high molecular weight polyethylene fiber with good high temperature resistance as described in any one of claims 1-6.

8. An application of the ultra-high molecular weight polyethylene fiber with good high-temperature resistance as described in claim 7, characterized in that: It is used in bulletproof protection and low-altitude economic fields.

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