A nano-particle reinforced polytetrafluoroethylene pipe and its preparation method

Abstract

The present invention relates to the technical field of pipe materials, and particularly relates to a nano-particle reinforced polytetrafluoroethylene pipe and a preparation method thereof. The nano-particle reinforced polytetrafluoroethylene pipe is obtained by extrusion molding and high-temperature sintering of a nano-particle reinforced polytetrafluoroethylene masterbatch; the nano-particle reinforced polytetrafluoroethylene masterbatch is obtained by melt stirring and extrusion granulation of modified nano boron nitride and polytetrafluoroethylene powder; wherein, the modified nano boron nitride is obtained by being wrapped with a cross-linked network constructed by perfluorohexylethyl methacrylate, ethyl methacrylate and trimethylolpropane triacrylate. The nano-particle reinforced polytetrafluoroethylene pipe prepared by the present invention has excellent mechanical properties and wear resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of pipe materials, and particularly to a nano-particle reinforced polytetrafluoroethylene pipe and a preparation method thereof. Background Art

[0002] Polytetrafluoroethylene (PTFE) pipes are widely used in fields such as chemical engineering, electronics, and machinery due to their excellent chemical inertness, high temperature resistance, and low friction coefficient. However, the inherent defects of PTFE, such as low mechanical strength and wear resistance, limit its use in applications that require high strength and wear resistance. To overcome these drawbacks, researchers have attempted to improve the performance of PTFE through various modification methods. Traditionally, adding fillers (such as glass fibers, carbon fibers, etc.) is a method to enhance the performance of PTFE, but this usually leads to a decline in other properties of the material.

[0003] In recent years, the introduction of nanomaterials has provided new possibilities for the modification of PTFE. Nano boron nitride (BN) has become an ideal choice for enhancing PTFE due to its excellent thermal stability and mechanical properties. However, directly adding nano boron nitride to PTFE can, to a certain extent, improve the performance of the material, but due to poor interfacial compatibility, it is difficult to achieve an ideal enhancement effect. Therefore, how to improve the compatibility between nano boron nitride and the PTFE matrix, and thus significantly enhance the comprehensive performance of PTFE, has become the focus of current research. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a nano-particle reinforced polytetrafluoroethylene pipe and a preparation method thereof to solve the problem of poor wear resistance of polytetrafluoroethylene pipes.

[0005] Based on the above purpose, the present invention provides a nano-particle reinforced polytetrafluoroethylene pipe, which is obtained by extrusion molding and high-temperature sintering of a nano-particle reinforced polytetrafluoroethylene masterbatch.

[0006] Further, the nano-particle reinforced polytetrafluoroethylene masterbatch is obtained by melt stirring and extrusion granulation of modified nano boron nitride and polytetrafluoroethylene powder.

[0007] Further, the weight ratio of the modified nano boron nitride to the polytetrafluoroethylene powder is 30 - 70:1000.

[0008] Further, the preparation method of the modified nano boron nitride is as follows:

[0009] (1) Under a nitrogen atmosphere, hydroxyl-functionalized nano boron nitride and triethylamine are added to tetrahydrofuran, sonicated for 10 - 30 min, stirred for 20 - 40 min, then 2-bromoisobutyryl bromide is added, the temperature is lowered to -5 - 0 °C, stirred for 2 - 4 h, then the temperature is raised to room temperature and stirred for 36 - 60 h, centrifuged, washed, and dried to obtain nano boron nitride with initiating sites on its surface;

[0010] (2) Under a nitrogen atmosphere, nano boron nitride with initiating sites on its surface, copper chloride, perfluorohexylethyl methacrylate, ethyl methacrylate, trimethylolpropane triacrylate, and tetrahydrofuran are mixed and stirred for 20 - 40 min, then 1,1,4,7,10,10-hexamethyltriethylenetetramine is added, the temperature is raised to 65 - 75 °C, stirred for 40 - 55 h, then perfluorohexylethyl methacrylate is added dropwise. After the addition is complete, stirred for 10 - 14 h, centrifuged, washed, and dried to obtain modified nano boron nitride.

[0011] Preferably, in step (1), the weight ratio of hydroxyl-functionalized nano boron nitride, triethylamine, tetrahydrofuran, and 2-bromoisobutyryl bromide is 30 - 70:7 - 20:300 - 700:6 - 18.

[0012] Preferably, in step (2), the weight ratio of nano boron nitride with initiating sites on its surface, copper chloride, perfluorohexylethyl methacrylate, ethyl methacrylate, trimethylolpropane triacrylate, tetrahydrofuran, and 1,1,4,7,10,10-hexamethyltriethylenetetramine is 30 - 70:10 - 20:40 - 100:150 - 250:5 - 20:200 - 300:35 - 70.

[0013] Preferably, in step (2), the weight ratio of perfluorohexylethyl methacrylate added for the first time to perfluorohexylethyl methacrylate added for the second time is 3 - 7:1 - 3.

[0014] Preferably, the average particle size of the polytetrafluoroethylene powder is 100 - 300 μm.

[0015] Preferably, the temperature of the melt stirring is 440 - 460 °C and the time is 1.5 - 2.5 h.

[0016] Preferably, the preparation method of the hydroxyl-functionalized nano boron nitride is as follows: The nano boron nitride is dispersed in deionized water, then sodium hydroxide is added, the temperature is raised to 55 - 65 °C, stirred for 10 - 15 h, centrifuged, washed, and dried to obtain hydroxyl-functionalized nano boron nitride.

[0017] Preferably, the average particle size of the nano boron nitride is 20 - 100 nm.

[0018] Preferably, the weight ratio of the nano boron nitride, deionized water and sodium hydroxide is 30-70:300-700:50-200.

[0019] Furthermore, the present invention also provides a preparation method of a nano-particle reinforced polytetrafluoroethylene pipe, comprising the following steps: loading the nano-particle reinforced polytetrafluoroethylene masterbatch into a mold for preforming to form a cylindrical blank, then putting the cylindrical blank into an extruder to extrude and form a tubular material, and finally sintering and cooling the tubular material to obtain a nano-particle reinforced polytetrafluoroethylene pipe.

[0020] Preferably, the sintering temperature is 350-370 °C and the time is 2.5-3.5 h.

[0021] Advantages of the present invention:

[0022] By preparing the nano-particle reinforced polytetrafluoroethylene pipe, the mechanical properties and wear resistance of the material are significantly improved. Compared with the polytetrafluoroethylene pipe directly added with nano boron nitride, the pipe of the present invention shows higher performance in terms of tensile strength and elongation at break, especially in terms of wear resistance, with the wear volume reduced by 70%.

[0023] The introduction of the outer fluorine chain of nano boron nitride significantly improves the tensile strength and elongation at break of the material. The presence of the fluorine chain promotes the penetration of the polytetrafluoroethylene molecular chain into the polymerization network on the surface of nano boron nitride during the melting process, forming a mechanical interlocking structure. This structure not only enhances the compatibility between nano boron nitride and polytetrafluoroethylene, but also greatly improves the wear resistance of the material. The use of trimethylolpropane triacrylate as a crosslinking agent further improves the mechanical properties and wear resistance of the pipe. This crosslinking agent helps to construct a network structure in nano boron nitride, providing more space for the penetration of polytetrafluoroethylene molecular chains, thereby enhancing the overall strength and wear resistance of the material. In addition, the perfluorohexylethyl methacrylate added secondly forms a linear fluorine chain on the surface of nano boron nitride, which not only improves the compatibility with polytetrafluoroethylene, but also enhances the interaction force between nano boron nitride and the polytetrafluoroethylene matrix through the entanglement with the polytetrafluoroethylene molecular chain. This enhanced interaction force further improves the mechanical properties and wear resistance of the material. Specific embodiments

[0024] To make the purpose, technical solutions and advantages of the present invention clearer and more understandable, the following further details the present invention in combination with specific embodiments.

[0025] In the specific embodiments of the present invention, the average particle size of the polytetrafluoroethylene powder is 200 μm, and the average particle size of the nano boron nitride is 50 nm. Example 1:

[0026] (1) Disperse 30 g of nano boron nitride in 300 g of deionized water, then add 50 g of sodium hydroxide, heat up to 55 °C, stir for 10 h, centrifuge, wash, and dry to obtain hydroxylated nano boron nitride;

[0027] (2) Under a nitrogen atmosphere, add 30 g of hydroxylated nano boron nitride and 7 g of triethylamine to 300 g of tetrahydrofuran, ultrasonicate for 10 min, stir for 20 min, then add 6 g of 2-bromoisobutyryl bromide, cool down to -5 °C, stir for 2 h, then heat up to room temperature and stir for 36 h, centrifuge, wash, and dry to obtain nano boron nitride with initiating sites on the surface;

[0028] (3) Under a nitrogen atmosphere, mix 30 g of nano boron nitride with initiating sites on the surface, 10 g of copper chloride, 30 g of perfluorohexylethyl methacrylate, 150 g of ethyl methacrylate, 5 g of trimethylolpropane triacrylate, and 200 g of tetrahydrofuran, stir for 20 min, then add 35 g of 1,1,4,7,10,10-hexamethyltriethylenetetramine, heat up to 65 °C, stir for 40 h, then dropwise add 10 g of perfluorohexylethyl methacrylate. After the dropwise addition, stir for 10 h, centrifuge, wash, and dry to obtain modified nano boron nitride;

[0029] (4) Melt 30 g of modified nano boron nitride and 1000 g of polytetrafluoroethylene powder at 440 °C, stir for 1.5 h, then extrude and pelletize to obtain a nano-particle reinforced polytetrafluoroethylene masterbatch. Then, load the nano-particle reinforced polytetrafluoroethylene masterbatch into a mold for preforming to form a cylindrical blank. Next, put the cylindrical blank into an extruder and extrude to form a tubular material. Finally, sinter the tubular material at 350 °C for 2.5 h and cool to obtain a nano-particle reinforced polytetrafluoroethylene pipe. Example 2:

[0030] (1) Disperse 50 g of nano boron nitride in 500 g of deionized water, then add 100 g of sodium hydroxide, heat up to 60 °C, stir for 12 h, centrifuge, wash, and dry to obtain hydroxylated nano boron nitride;

[0031] (2) Under a nitrogen atmosphere, add 50 g of hydroxylated nano boron nitride and 12.5 g of triethylamine to 500 g of tetrahydrofuran, ultrasonicate for 20 min, stir for 30 min, then add 12 g of 2-bromoisobutyryl bromide, cool down to 0 °C, stir for 3 h, then heat up to room temperature and stir for 48 h, centrifuge, wash, and dry to obtain nano boron nitride with initiating sites on the surface;

[0032] (3) Under a nitrogen atmosphere, 50 g of nano boron nitride with initiation sites on the surface, 15 g of copper chloride, 50 g of perfluorohexylethyl methacrylate, 200 g of ethyl methacrylate, 10 g of trimethylolpropane triacrylate, and 250 g of tetrahydrofuran were mixed and stirred for 30 min. Then, 50 g of 1,1,4,7,10,10 - hexamethyltriethylenetetramine was added, the temperature was raised to 70 °C, and the mixture was stirred for 48 h. Then, 20 g of perfluorohexylethyl methacrylate was added dropwise. After the addition was complete, the mixture was stirred for 12 h, centrifuged, washed, and dried to obtain modified nano boron nitride;

[0033] (4) 50 g of modified nano boron nitride and 1000 g of polytetrafluoroethylene powder were melted at 450 °C, stirred for 2 h, then extruded and pelletized to obtain a nano - particle - reinforced polytetrafluoroethylene masterbatch. The nano - particle - reinforced polytetrafluoroethylene masterbatch was pre - formed in a mold to form a cylindrical blank. Then, the cylindrical blank was put into an extruder and extruded to form a tubular material. Finally, the tubular material was sintered at 360 °C for 3 h and cooled to obtain a nano - particle - reinforced polytetrafluoroethylene pipe. Example 3:

[0034] (1) 70 g of nano boron nitride was dispersed in 700 g of deionized water, then 200 g of sodium hydroxide was added, the temperature was raised to 65 °C, and the mixture was stirred for 15 h, centrifuged, washed, and dried to obtain hydroxylated nano boron nitride;

[0035] (2) Under a nitrogen atmosphere, 70 g of hydroxylated nano boron nitride and 20 g of triethylamine were added to 700 g of tetrahydrofuran, ultrasonicated for 30 min, stirred for 40 min, then 18 g of 2 - bromoisobutyryl bromide was added, the temperature was lowered to 0 °C, and the mixture was stirred for 4 h. Then, the temperature was raised to room temperature and stirred for 60 h, centrifuged, washed, and dried to obtain nano boron nitride with initiation sites on the surface;

[0036] (3) Under a nitrogen atmosphere, 70 g of nano boron nitride with initiation sites on the surface, 20 g of copper chloride, 70 g of perfluorohexylethyl methacrylate, 250 g of ethyl methacrylate, 20 g of trimethylolpropane triacrylate, and 300 g of tetrahydrofuran were mixed and stirred for 40 min. Then, 70 g of 1,1,4,7,10,10 - hexamethyltriethylenetetramine was added, the temperature was raised to 75 °C, and the mixture was stirred for 55 h. Then, 30 g of perfluorohexylethyl methacrylate was added dropwise. After the addition was complete, the mixture was stirred for 14 h, centrifuged, washed, and dried to obtain modified nano boron nitride;

[0037] (4) 70 g of modified nano boron nitride and 1000 g of polytetrafluoroethylene powder are melted at 460 °C, stirred for 2 h, and then extruded and granulated to obtain a nano-particle reinforced polytetrafluoroethylene masterbatch. The nano-particle reinforced polytetrafluoroethylene masterbatch is then loaded into a mold for preforming to form a cylindrical blank. The cylindrical blank is then placed in an extruder and extruded to form a tubular material. Finally, the tubular material is sintered at 370 °C for 3.5 h and cooled to obtain a nano-particle reinforced polytetrafluoroethylene pipe.

[0038] Comparative Example 1:

[0039] The difference between Comparative Example 1 and Example 2 is that the perfluorohexylethyl methacrylate in step (3) is replaced by ethyl methacrylate;

[0040] The specific steps are as follows:

[0041] (1) 50 g of nano boron nitride is dispersed in 500 g of deionized water, then 100 g of sodium hydroxide is added, the temperature is raised to 60 °C, stirred for 12 h, centrifuged, washed, and dried to obtain hydroxylated nano boron nitride;

[0042] (2) Under a nitrogen atmosphere, 50 g of hydroxylated nano boron nitride and 12.5 g of triethylamine are added to 500 g of tetrahydrofuran, sonicated for 20 min, stirred for 30 min, then 12 g of 2-bromo isobutyryl bromide is added, the temperature is lowered to 0 °C, stirred for 3 h, then the temperature is raised to room temperature, stirred for 48 h, centrifuged, washed, and dried to obtain nano boron nitride with initiating sites on the surface;

[0043] (3) Under a nitrogen atmosphere, 50 g of nano boron nitride with initiating sites on the surface, 15 g of copper chloride, 250 g of ethyl methacrylate, 10 g of trimethylolpropane triacrylate, and 250 g of tetrahydrofuran are mixed, stirred for 30 min, then 50 g of 1,1,4,7,10,10-hexamethyltriethylenetetramine is added, the temperature is raised to 70 °C, stirred for 48 h, then 20 g of ethyl methacrylate is added dropwise. After the dropwise addition is completed, stirred for 12 h, centrifuged, washed, and dried to obtain modified nano boron nitride;

[0044] (4) 50 g of modified nano boron nitride and 1000 g of polytetrafluoroethylene powder are melted at 450 °C, stirred for 2 h, and then extruded and granulated to obtain a nano-particle reinforced polytetrafluoroethylene masterbatch. The nano-particle reinforced polytetrafluoroethylene masterbatch is then loaded into a mold for preforming to form a cylindrical blank. The cylindrical blank is then placed in an extruder and extruded to form a tubular material. Finally, the tubular material is sintered at 360 °C for 3 h and cooled to obtain a polytetrafluoroethylene pipe.

[0045] Comparative Example 2:

[0046] The difference between Comparative Example 2 and Example 2 is that in step (3), trimethylolpropane triacrylate is replaced by ethyl methacrylate;

[0047] The specific preparation steps are as follows:

[0048] (1) Disperse 50 g of nano boron nitride in 500 g of deionized water, then add 100 g of sodium hydroxide, heat up to 60 °C, stir for 12 h, centrifuge, wash, and dry to obtain hydroxylated nano boron nitride;

[0049] (2) Under a nitrogen atmosphere, add 50 g of hydroxylated nano boron nitride and 12.5 g of triethylamine to 500 g of tetrahydrofuran, ultrasonicate for 20 min, stir for 30 min, then add 12 g of 2-bromoisobutyryl bromide, cool down to 0 °C, stir for 3 h, then heat up to room temperature, stir for 48 h, centrifuge, wash, and dry to obtain nano boron nitride with initiating sites on the surface;

[0050] (3) Under a nitrogen atmosphere, mix 50 g of nano boron nitride with initiating sites on the surface, 15 g of copper chloride, 50 g of perfluorohexylethyl methacrylate, 210 g of ethyl methacrylate, and 250 g of tetrahydrofuran, stir for 30 min, then add 50 g of 1,1,4,7,10,10-hexamethyltriethylenetetramine, heat up to 70 °C, stir for 48 h, then dropwise add 20 g of perfluorohexylethyl methacrylate. After the addition is complete, stir for 12 h, centrifuge, wash, and dry to obtain modified nano boron nitride;

[0051] (4) Melt 50 g of modified nano boron nitride and 1000 g of polytetrafluoroethylene powder at 450 °C, stir for 2 h, then extrude and pelletize to obtain a nano-particle reinforced polytetrafluoroethylene masterbatch. Then, load the nano-particle reinforced polytetrafluoroethylene masterbatch into a mold for preforming to form a cylindrical blank. Then, put the cylindrical blank into an extruder to extrude into a tubular material. Finally, sinter the tubular material at 360 °C for 3 h and cool to obtain a polytetrafluoroethylene pipe.

[0052] Comparative Example 3:

[0053] The difference between Comparative Example 3 and Example 2 is that in step (3), perfluorohexylethyl methacrylate is not added a second time;

[0054] The specific preparation steps are as follows:

[0055] (1) Disperse 50 g of nano boron nitride in 500 g of deionized water, then add 100 g of sodium hydroxide, heat up to 60 °C, stir for 12 h, centrifuge, wash, and dry to obtain hydroxylated nano boron nitride;

[0056] (2) Under a nitrogen atmosphere, 50 g of hydroxylated nano boron nitride and 12.5 g of triethylamine were added to 500 g of tetrahydrofuran, ultrasonicated for 20 min, stirred for 30 min, then 12 g of 2-bromo isobutyryl bromide was added, cooled to 0 °C, stirred for 3 h, then warmed to room temperature and stirred for 48 h, centrifuged, washed, and dried to obtain nano boron nitride with initiating sites on its surface;

[0057] (3) Under a nitrogen atmosphere, 50 g of nano boron nitride with initiating sites on its surface, 15 g of copper chloride, 50 g of perfluorohexylethyl methacrylate, 200 g of ethyl methacrylate, 10 g of trimethylolpropane triacrylate, and 250 g of tetrahydrofuran were mixed and stirred for 30 min, then 50 g of 1,1,4,7,10,10-hexamethyltriethylenetetramine was added, warmed to 70 °C, and stirred for 48 h, centrifuged, washed, and dried to obtain modified nano boron nitride;

[0058] (4) 50 g of modified nano boron nitride and 1000 g of polytetrafluoroethylene powder were melted at 450 °C, stirred for 2 h, then extruded and granulated to obtain a nano particle-reinforced polytetrafluoroethylene masterbatch. The nano particle-reinforced polytetrafluoroethylene masterbatch was then preformed in a mold to form a cylindrical blank, and the cylindrical blank was put into an extruder to extrude a tubular material. Finally, the tubular material was sintered at 360 °C for 3 h and cooled to obtain a polytetrafluoroethylene pipe.

[0059] Comparative Example 4:

[0060] The difference between Comparative Example 4 and Example 2 is that the modified nano boron nitride in step (4) was replaced with nano boron nitride;

[0061] The specific preparation steps are as follows:

[0062] 50 g of nano boron nitride and 1000 g of polytetrafluoroethylene powder were melted at 450 °C, stirred for 2 h, then extruded and granulated to obtain a nano particle-reinforced polytetrafluoroethylene masterbatch. The nano particle-reinforced polytetrafluoroethylene masterbatch was then preformed in a mold to form a cylindrical blank, and the cylindrical blank was put into an extruder to extrude a tubular material. Finally, the tubular material was sintered at 360 °C for 3 h and cooled to obtain a nano particle-reinforced polytetrafluoroethylene pipe.

[0063] Performance test:

[0064] Tensile property test: Conducted on a universal testing machine, tested according to GB / T 1040—1992, and the results are shown in Table 1.

[0065] Wear resistance: On a multi-functional friction and wear testing machine, the tribological properties of the material surface were tested through a reciprocating sliding friction and wear test in a ball-plane contact mode. The friction pair was a GCr15 bearing steel ball with a diameter of 10 mm, the normal load was 7 N, the reciprocating displacement was 10 mm, the frequency was 2 Hz, and the reciprocating sliding time was 3600 s. 10 specimens were tested for each example and comparative example. The wear volume of the specimen surface was measured using a laser confocal microscope, and the average value was taken. The results are shown in Table 1.

[0066] Table 1 Performance test results

[0067]

[0068] Data analysis:

[0069] From the data of Examples 1-3 and Comparative Example 4 in Table 1, it can be seen that compared with directly adding nano boron nitride, the nano particle-reinforced polytetrafluoroethylene pipe prepared by the present invention has higher tensile strength and elongation at break. Most importantly, the wear resistance is greatly improved. Compared with the polytetrafluoroethylene pipe directly adding nano boron nitride, the wear volume has decreased by 70%.

[0070] From the data of Example 2 and Comparative Example 1 in Table 1, it can be seen that the introduction of the outer fluorine chain of nano boron nitride helps to further improve the tensile strength and elongation at break, and makes an outstanding contribution to the improvement of wear resistance. This is mainly because the introduction of the fluorine chain helps the molecular chain of polytetrafluoroethylene to penetrate into the polymerization network on the surface of nano boron nitride during the melting process, thereby forming a mechanical interlocking structure and improving the compatibility between nano boron nitride and polytetrafluoroethylene.

[0071] From the data of Example 2 and Comparative Example 2 in Table 1, it can be seen that trimethylolpropane triacrylate as a cross-linking agent helps to improve the mechanical properties and wear resistance of the pipe. This is mainly because trimethylolpropane triacrylate helps to construct a network structure in nano boron nitride, providing space for the penetration of polytetrafluoroethylene molecular chains.

[0072] From the data of Example 2 and Comparative Example 3 in Table 1, it can be seen that the second addition of perfluorohexylethyl methacrylate helps to improve the mechanical properties and wear resistance of the pipe. This is mainly because the second addition of perfluorohexylethyl methacrylate can form linear fluorine chains on the outer layer of the network structure on the surface of nano boron nitride. On the one hand, it improves the compatibility with polytetrafluoroethylene, and on the other hand, it can form entanglements with the molecular chains of polytetrafluoroethylene, improving the interaction force between nano boron nitride and the polytetrafluoroethylene matrix.

[0073] Those of ordinary skill in the art should understand that any discussion of the above embodiments is exemplary only and is not intended to imply that the scope of the present invention is limited to these examples; under the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present invention as described above, which are not provided in detail for the sake of brevity.

Claims

1. A nanoparticle-reinforced polytetrafluoroethylene pipe, characterized in that: It is obtained by extruding nanoparticle-reinforced polytetrafluoroethylene masterbatch and sintering at high temperature; The nano-particle-reinforced polytetrafluoroethylene masterbatch is obtained by melting and stirring modified nano-boron nitride and polytetrafluoroethylene powder, and then extruding and granulating. The weight ratio of the modified nano boron nitride to polytetrafluoroethylene powder is 30-70:1000; The preparation method of the modified nano boron nitride is as follows: (1) Under a nitrogen atmosphere, hydroxylated nano-boron nitride and triethylamine are added to tetrahydrofuran, ultrasonicated for 10-30 minutes, stirred for 20-40 minutes, and then 2-bromoisobutyryl bromide is added. The temperature is lowered to -5-0°C, stirred for 2-4 hours, then heated to room temperature, stirred for 36-60 hours, centrifuged, washed, and dried to obtain nano-boron nitride with initiation sites on the surface; (2) In a nitrogen atmosphere, nano boron nitride with initiation sites on the surface, copper chloride, perfluorohexylethyl methacrylate, ethyl methacrylate, trimethylolpropane triacrylate and tetrahydrofuran are mixed and stirred for 20-40 minutes, and then 1,1,4,7,10,10-hexamethyltriethylenetetramine is added, the temperature is raised to 65-75°C, and the mixture is stirred for 40-55 hours. Then, perfluorohexylethyl methacrylate is added dropwise, and after the addition is completed, the mixture is stirred for 10-14 hours, centrifuged, washed, and dried to obtain modified nano boron nitride; In the step (1), the weight ratio of hydroxylated nano-boron nitride, triethylamine, tetrahydrofuran and 2-bromoisobutyryl bromide is 30-70:7-20:300-700:6-18; In the step (2), the weight ratio of the nano boron nitride having the initiation site on the surface, copper chloride, perfluorohexylethyl methacrylate, ethyl methacrylate, trimethylolpropane triacrylate, tetrahydrofuran and 1,1,4,7,10,10-hexamethyltriethylenetetramine is 30-70:10-20:40-100:150-250:5-20:200-300:35-70; In the step (2), the weight ratio of the perfluorohexylethyl methacrylate added for the first time to the perfluorohexylethyl methacrylate added for the second time is 3-7:1-3.

2. The nanoparticle-reinforced polytetrafluoroethylene tube according to claim 1, characterized in that: The average particle size of the polytetrafluoroethylene powder is 100-300 μm.

3. The nanoparticle-reinforced polytetrafluoroethylene tube according to claim 1, characterized in that: The temperature of the melt stirring is 440-460° C., and the time is 1.5-2.5 h.

4. The nanoparticle-reinforced polytetrafluoroethylene tube according to claim 1, characterized in that: The preparation method of the hydroxylated nano boron nitride is as follows: disperse the nano boron nitride in deionized water, then add sodium hydroxide, heat to 55-65° C., stir for 10-15 hours, centrifuge, wash, and dry to obtain the hydroxylated nano boron nitride.

5. The nanoparticle-reinforced polytetrafluoroethylene tube according to claim 4, characterized in that: The average particle size of the nano boron nitride is 20-100 nm.

6. The nanoparticle-reinforced polytetrafluoroethylene tube according to claim 4, characterized in that: The weight ratio of the nano boron nitride, deionized water and sodium hydroxide is 30-70:300-700:50-200.

7. A method for preparing a nanoparticle-reinforced polytetrafluoroethylene tube according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: placing nano-particle-reinforced polytetrafluoroethylene master batch into a mold for preforming to form a cylindrical blank, placing the cylindrical blank into an extruder for extrusion to form a tubular material, and finally sintering and cooling the tubular material to obtain a nano-particle-reinforced polytetrafluoroethylene tubular material.

8. The method for preparing the nanoparticle-reinforced polytetrafluoroethylene pipe according to claim 7, characterized in that: The sintering temperature is 350-370° C. and the sintering time is 2.5-3.5 hours.

Images