Modified ptf material, its preparation method and application in wind bag pump

Abstract

The application belongs to the technical field of high polymer materials, and particularly relates to a modified PTFE material, a preparation method thereof and application of the modified PTFE material in a wind bag pump. The modified PTFE material comprises the following components in mass fraction: modified polytetrafluoroethylene 100 parts, carbon fluoride fiber 10-20 parts, fluorinated polyimide fiber 5-10 parts, and fluorinated inorganic filler 5-10 parts; the modified polytetrafluoroethylene is obtained by copolymerization of tetrafluoroethylene, perfluoro-2-butene and perfluoroalkyl vinyl ether. The mechanical property, bending resistance and wear resistance of the modified PTFE material are enhanced, the corrosion resistance is maintained, and the modified PTFE material is easy to be processed into a long-life wind bag.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a modified PTFE material, its preparation method, and its application in airbag pumps. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] In semiconductor wet manufacturing processes, dozens of ultrapure acids, alkalis, and water are often used in etching, grinding, and cleaning processes. These liquids are typically transported using a blower pump. The blower pump adjusts its volume by expanding and contracting its internal blower to draw in and discharge the liquid. The blower is the core component of the blower pump. During operation, the blower continuously reciprocates, and stress concentration occurs during its elongation and contraction. Prolonged operation can lead to localized fatigue damage. When the blower deforms beyond its pressure resistance limit, excessive deformation or rupture occurs. Blower rupture can cause chemical leakage, leading to safety accidents, semiconductor equipment downtime, significant economic losses, and even personal injury. Therefore, the materials used to manufacture the blower must possess excellent mechanical properties, fatigue resistance, and deformation resistance to prevent rupture.

[0004] Because corrosive chemicals such as hydrofluoric acid, hydrochloric acid, nitric acid, and sodium hydroxide are used in wet processing, the air bladder of the air bladder pump must be made of corrosion-resistant materials. Polytetrafluoroethylene (PTFE) has excellent corrosion resistance and stability, which can well meet the requirements for conveying various ultrapure and corrosive liquids in semiconductor manufacturing processes. However, PTFE has low mechanical strength and poor bending and wear resistance, which is not conducive to the processing and long-term use of the air bladder. Although filling with fillers can improve the mechanical properties of PTFE to some extent, the compatibility between PTFE and fillers is poor, and the corrosion resistance of the fillers also needs to meet the requirements of the air bladder for transporting corrosive liquids. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a modified PTFE material, its preparation method, and its application in airbag pumps. The modified PTFE material exhibits enhanced mechanical properties, improved bending resistance and wear resistance, while maintaining its corrosion resistance, and is easily processed into long-life airbags.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0007] In a first aspect, the present invention provides a modified PTFE material comprising, by mass parts: 100 parts of modified polytetrafluoroethylene, 10-20 parts of fluorinated carbon fiber, 5-10 parts of fluorinated polyimide fiber, and 5-10 parts of fluorinated inorganic filler.

[0008] The modified polytetrafluoroethylene is copolymerized from tetrafluoroethylene, perfluoro-2-butene, and perfluoroalkyl vinyl ether.

[0009] Preferably, the molar ratio of tetrafluoroethylene, perfluoro-2-butene, and perfluoroalkyl vinyl ether is 1:(0.1-0.2):(0.1-0.2).

[0010] Preferably, the perfluoroalkyl vinyl ether comprises at least one of perfluoromethyl vinyl ether, perfluoroethyl vinyl ether, or perfluoropropyl vinyl ether.

[0011] Preferably, the fluorinated carbon fiber has a fluorine content of 2% to 5%, a single filament diameter of 10 to 20 μm, and an aspect ratio of 10 to 30.

[0012] Preferably, the fluorinated polyimide fiber has a fluorine content of 2% to 5%, a single filament diameter of 10 to 20 μm, and an aspect ratio of 10 to 30.

[0013] Preferably, the mass ratio of the fluorinated carbon fiber to the fluorinated polyimide fiber is (1-2):1.

[0014] Preferably, the fluorinated inorganic filler includes at least one of fluorinated carbon nitride, fluorinated boron nitride, or fluorinated graphite.

[0015] In a second aspect, the present invention provides a method for preparing the modified PTFE material as described in the first aspect, comprising the following steps:

[0016] Modified polytetrafluoroethylene, fluorinated carbon fiber, fluorinated polyimide fiber and fluorinated inorganic filler are mixed and then kneaded, followed by low-temperature molding and high-temperature sintering to obtain modified PTFE material.

[0017] Optionally, the mixing temperature can be 320-340℃.

[0018] Optionally, the low-temperature molding temperature can be -15℃ to 25℃, and the pressure can be 10 to 50 MPa. Optionally, the low-temperature molding temperature can be -10℃ to 10℃.

[0019] Optionally, the sintering temperature can be 250–400℃, and the time can be 5–15 hours.

[0020] Preferably, it also includes a method for preparing modified polytetrafluoroethylene, comprising the following steps:

[0021] Modified polytetrafluoroethylene (PTFE) is obtained by mixing tetrafluoroethylene, perfluoro-2-butene, perfluoroalkyl vinyl ether, and an initiator and then polymerizing them. Optionally, the polymerization temperature is 70℃~80℃.

[0022] More preferably, the initiator includes at least one of diisopropyl peroxide, dibutyl peroxide, or benzoyl peroxide.

[0023] Preferably, the fluorinated carbon fiber is prepared by fluorination of carbon fiber in a mixture of fluorine and nitrogen. Optionally, the fluorination reaction temperature of the fluorinated carbon fiber is 200℃~300℃, and the fluorination time is 1~4h.

[0024] Preferably, the fluorinated polyimide fiber is prepared by fluorination of polyimide fiber in a mixture of fluorine and nitrogen. Optionally, the fluorination reaction temperature of the fluorinated polyimide fiber is 280℃~380℃, and the fluorination time is 1~5h.

[0025] Thirdly, the present invention provides the application of the modified PTFE material as described in the first aspect in a windbag pump, the application including the preparation of a windbag.

[0026] The beneficial effects achieved by one or more technical solutions of the present invention are as follows:

[0027] The mechanical properties, bending resistance, and wear resistance of modified PTFE materials are enhanced, while their corrosion resistance is maintained, making them easy to process into long-life airbags.

[0028] Modified PTFE is obtained by copolymerizing tetrafluoroethylene, perfluoro-2-butene, and perfluoroalkyl vinyl ethers, while maintaining the rigidity of the PTFE main chain and introducing flexible segments. Fluorinated carbon fibers, fluorinated polyimide fibers, and fluorinated inorganic fillers are compatible with the modified PTFE and are used together to form a network reinforcement structure in which two-dimensional fillers are embedded in three-dimensional fibers, giving the modified PTFE material excellent mechanical properties and stability. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments and comparative examples.

[0030] Example 1

[0031] Tetrafluoroethylene, perfluoro-2-butene, and perfluoroethyl vinyl ether were mixed in a molar ratio of 1:0.2:0.2 to obtain a mixed monomer. Diisopropyl peroxide was added to the mixed monomer at a mass of 0.1% of the total mass of the mixed monomer, and the mixture was polymerized at 70°C and 2 MPa for 5 h to obtain modified polytetrafluoroethylene.

[0032] Carbon fibers with a single filament diameter of 20 μm and an aspect ratio of 20 were placed in a sealed vacuum reactor. The reactor was then evacuated and the air in the reactor was replaced with nitrogen three times. A fluorine / nitrogen mixture with a volume ratio of 1:1 was then introduced into the vacuum reactor. The fluorination temperature was controlled at 200℃ and the fluorination time was 3 hours to make the fluorine content of the fluorinated carbon fiber 5%. After the reaction was completed, the reaction gas in the reactor was replaced with nitrogen several times before the fluorinated carbon fiber was removed.

[0033] Polyimide fibers with a monofilament diameter of 20 μm and an aspect ratio of 20 were placed in a sealed vacuum reactor. The reactor was then evacuated and the air in the reactor was replaced with nitrogen three times. A fluorine / nitrogen mixture with a volume ratio of 1:1 was then introduced into the vacuum reactor. The fluorination temperature was controlled at 300℃ and the time was controlled at 3h to make the fluorine content of the fluorinated polyimide fibers 5%. After the reaction was completed, the reaction gas in the reactor was replaced with nitrogen several times before the fluorinated polyimide fibers were removed.

[0034] Two-dimensional boron nitride was placed in a sealed vacuum reactor, then evacuated and the air in the reactor was replaced with nitrogen three times. Then, a fluorine / nitrogen mixture with a volume ratio of 1:1 was introduced into the vacuum reactor and fluorinated at 50°C for 10 minutes. After the reaction was completed, the reaction gas in the reactor was replaced with nitrogen several times before the fluorinated boron nitride was removed.

[0035] 100 parts of modified polytetrafluoroethylene, 15 parts of fluorinated carbon fiber, 10 parts of fluorinated polyimide fiber and 5 parts of fluorinated boron nitride were added to a mixer and mixed for 30 minutes. The mixture was then internally mixed in a mixer at 330°C, and then molded at 20°C and 20MPa. Finally, it was sintered at 360°C for 10 hours to obtain the modified PTFE material.

[0036] Example 2

[0037] Tetrafluoroethylene, perfluoro-2-butene, and perfluoroethyl vinyl ether were mixed in a molar ratio of 1:0.1:0.2 to obtain a mixed monomer. Diisopropyl peroxide was added to the mixed monomer at a mass of 0.1% of the total mass of the mixed monomer, and the mixture was polymerized at 75°C and 2 MPa for 5 h to obtain modified polytetrafluoroethylene.

[0038] The preparation of fluorinated carbon fiber, fluorinated polyimide fiber and fluorinated boron nitride is the same as in Example 1.

[0039] 100 parts of modified polytetrafluoroethylene, 10 parts of fluorinated carbon fiber, 5 parts of fluorinated polyimide fiber and 5 parts of fluorinated boron nitride were added to a mixer and mixed for 30 minutes. The mixture was then internally mixed in a mixer at 340°C, and then molded at 10°C and 40MPa. Finally, it was sintered at 400°C for 10 hours to obtain the modified PTFE material.

[0040] Example 3

[0041] Tetrafluoroethylene, perfluoro-2-butene, and perfluoroethyl vinyl ether were mixed in a molar ratio of 1:0.2:0.1 to obtain a mixed monomer. Dibutyl peroxide dicarbonate was added to the mixed monomer at a mass of 0.1% of the total mass of the mixed monomer, and the mixture was polymerized at 70°C and 2 MPa for 5 h to obtain modified polytetrafluoroethylene.

[0042] The preparation of fluorinated carbon fiber, fluorinated polyimide fiber and fluorinated boron nitride is the same as in Example 1.

[0043] 100 parts of modified polytetrafluoroethylene, 10 parts of fluorinated carbon fiber, 5 parts of fluorinated polyimide fiber and 5 parts of fluorinated boron nitride were added to a mixer and mixed for 30 minutes. The mixture was then internally mixed in a mixer at 320°C, and then molded at -5°C and 30MPa. Finally, it was sintered at 350°C for 12 hours to obtain the modified PTFE material.

[0044] Example 4

[0045] Tetrafluoroethylene, perfluoro-2-butene, and perfluoroethyl vinyl ether were mixed in a molar ratio of 1:0.1:0.1 to obtain a mixed monomer. Diisopropyl peroxide was added to the mixed monomer at a mass of 0.1% of the total mass of the mixed monomer, and the mixture was polymerized at 70°C and 2 MPa for 5 h to obtain modified polytetrafluoroethylene.

[0046] The preparation of fluorinated carbon fiber, fluorinated polyimide fiber and fluorinated boron nitride is the same as in Example 1.

[0047] 100 parts of modified polytetrafluoroethylene, 10 parts of fluorinated carbon fiber, 5 parts of fluorinated polyimide fiber and 5 parts of fluorinated boron nitride were added to a mixer and mixed for 30 minutes. The mixture was then internally mixed in a mixer at 320°C, and then molded at -5°C and 30MPa. Finally, it was sintered at 350°C for 12 hours to obtain the modified PTFE material.

[0048] Example 5

[0049] The preparation of modified polytetrafluoroethylene, fluorinated carbon fiber, fluorinated polyimide fiber and fluorinated boron nitride is the same as in Example 1.

[0050] 100 parts of modified polytetrafluoroethylene, 10 parts of fluorinated carbon fiber, 10 parts of fluorinated polyimide fiber and 5 parts of fluorinated boron nitride were added to a mixer and mixed for 30 minutes. The mixture was then internally mixed in a mixer at 320°C, and then molded at -5°C and 30MPa. Finally, it was sintered at 350°C for 12 hours to obtain the modified PTFE material.

[0051] Example 6

[0052] The preparation of modified polytetrafluoroethylene, fluorinated carbon fiber, fluorinated polyimide fiber and fluorinated boron nitride is the same as in Example 1.

[0053] 100 parts of modified polytetrafluoroethylene, 20 parts of fluorinated carbon fiber, 10 parts of fluorinated polyimide fiber and 5 parts of fluorinated boron nitride were added to a mixer and mixed for 30 minutes. The mixture was then internally mixed in a mixer at 320°C, and then molded at -5°C and 30MPa. Finally, it was sintered at 350°C for 12 hours to obtain the modified PTFE material.

[0054] Example 7

[0055] Carbon fibers with a single filament diameter of 30 μm and an aspect ratio of 20 were placed in a sealed vacuum reactor. The reactor was then evacuated and the air in the reactor was replaced with nitrogen three times. A fluorine / nitrogen mixture with a volume ratio of 1:1 was then introduced into the vacuum reactor. The fluorination temperature was controlled at 200℃ and the time was controlled at 3 hours to make the fluorine content of the fluorinated carbon fiber 5%. After the reaction was completed, the reaction gas in the reactor was replaced with nitrogen several times before the fluorinated carbon fiber was removed.

[0056] Polyimide fibers with a monofilament diameter of 30 μm and an aspect ratio of 20 were placed in a sealed vacuum reactor. The reactor was then evacuated and the air in the reactor was replaced with nitrogen three times. A fluorine / nitrogen mixture with a volume ratio of 1:1 was then introduced into the vacuum reactor. The fluorination temperature was controlled at 350℃ and the time was 2.5 h to make the fluorine content of the fluorinated carbon fiber 5%. After the reaction was completed, the reaction gas in the reactor was replaced with nitrogen several times before the fluorinated polyimide fibers were removed.

[0057] The preparation of modified polytetrafluoroethylene and boron fluoride nitride is the same as in Example 1.

[0058] 100 parts of modified polytetrafluoroethylene, 10 parts of fluorinated carbon fiber, 5 parts of fluorinated polyimide fiber and 5 parts of fluorinated boron nitride were added to a mixer and mixed for 30 minutes. The mixture was then internally mixed in a mixer at 320°C, and then molded at -5°C and 30MPa. Finally, it was sintered at 350°C for 12 hours to obtain the modified PTFE material.

[0059] Example 8

[0060] Carbon fibers with a single filament diameter of 10 μm and an aspect ratio of 20 were placed in a sealed vacuum reactor. The reactor was then evacuated and the air in the reactor was replaced with nitrogen three times. A fluorine / nitrogen mixture with a volume ratio of 1:1 was then introduced into the vacuum reactor. The fluorination temperature was controlled at 240℃ and the time was controlled at 2h to make the fluorine content of the fluorinated carbon fiber 5%. After the reaction was completed, the reaction gas in the reactor was replaced with nitrogen several times before the fluorinated carbon fiber was removed.

[0061] Polyimide fibers with a single filament diameter of 10 μm and an aspect ratio of 20 were placed in a sealed vacuum reactor. The reactor was then evacuated and the air in the reactor was replaced with nitrogen three times. A mixture of fluorine and nitrogen in a volume ratio of 1:1 was then introduced into the vacuum reactor. The fluorination temperature was controlled at 300℃ and the time was 3 hours to make the fluorine content of the fluorinated carbon fiber 5%. After the reaction was completed, the reaction gas in the reactor was replaced with nitrogen several times before the fluorinated polyimide fibers were removed.

[0062] The preparation of modified polytetrafluoroethylene and boron fluoride nitride is the same as in Example 1.

[0063] 100 parts of modified polytetrafluoroethylene, 10 parts of fluorinated carbon fiber, 5 parts of fluorinated polyimide fiber and 5 parts of fluorinated boron nitride were added to a mixer and mixed for 30 minutes. The mixture was then internally mixed in a mixer at 320°C, and then molded at -5°C and 30MPa. Finally, it was sintered at 360°C for 12 hours to obtain the modified PTFE material.

[0064] Example 9

[0065] Carbon fibers with a single filament diameter of 20 μm and an aspect ratio of 30 were placed in a sealed vacuum reactor. The reactor was then evacuated and the air in the reactor was replaced with nitrogen three times. A fluorine / nitrogen mixture with a volume ratio of 1:1 was then introduced into the vacuum reactor. The fluorination temperature was controlled at 200℃ and the time was controlled at 3 hours to make the fluorine content of the fluorinated carbon fiber 5%. After the reaction was completed, the reaction gas in the reactor was replaced with nitrogen several times before the fluorinated carbon fiber was removed.

[0066] Polyimide fibers with a monofilament diameter of 20 μm and an aspect ratio of 30 were placed in a sealed vacuum reactor. The reactor was then evacuated and the air in the reactor was replaced with nitrogen three times. A mixture of fluorine and nitrogen in a volume ratio of 1:1 was then introduced into the vacuum reactor. The fluorination temperature was controlled at 300℃ and the time was 3 hours to make the fluorine content of the fluorinated carbon fiber 5%. After the reaction was completed, the reaction gas in the reactor was replaced with nitrogen several times before the fluorinated polyimide fibers were removed.

[0067] The preparation of modified polytetrafluoroethylene and boron fluoride nitride is the same as in Example 1.

[0068] 100 parts of modified polytetrafluoroethylene, 10 parts of fluorinated carbon fiber, 5 parts of fluorinated polyimide fiber and 5 parts of fluorinated boron nitride were added to a mixer and mixed for 30 minutes. The mixture was then internally mixed in a mixer at 320°C, and then molded at -5°C and 30MPa. Finally, it was sintered at 360°C for 12 hours to obtain the modified PTFE material.

[0069] Example 10

[0070] Carbon fibers with a single filament diameter of 20 μm and an aspect ratio of 10 were placed in a sealed vacuum reactor. The reactor was then evacuated and the air in the reactor was replaced with nitrogen three times. A fluorine / nitrogen mixture with a volume ratio of 1:1 was then introduced into the vacuum reactor. The fluorination temperature was controlled at 200℃ and the time was controlled at 3 hours to make the fluorine content of the fluorinated carbon fiber 5%. After the reaction was completed, the reaction gas in the reactor was replaced with nitrogen several times before the fluorinated carbon fiber was removed.

[0071] Polyimide fibers with a monofilament diameter of 20 μm and an aspect ratio of 10 were placed in a sealed vacuum reactor. The reactor was then evacuated and the air in the reactor was replaced with nitrogen three times. A mixture of fluorine and nitrogen in a volume ratio of 1:1 was then introduced into the vacuum reactor. The fluorination temperature was controlled at 300℃ and the time was 3 hours to make the fluorine content of the fluorinated carbon fiber 5%. After the reaction was completed, the reaction gas in the reactor was replaced with nitrogen several times before the fluorinated polyimide fibers were removed.

[0072] The preparation of modified polytetrafluoroethylene and boron fluoride nitride is the same as in Example 1.

[0073] 100 parts of modified polytetrafluoroethylene, 10 parts of fluorinated carbon fiber, 5 parts of fluorinated polyimide fiber and 5 parts of fluorinated boron nitride were added to a mixer and mixed for 30 minutes. The mixture was then internally mixed in a mixer at 320°C, and then molded at -5°C and 30MPa. Finally, it was sintered at 360°C for 12 hours to obtain the modified PTFE material.

[0074] Example 11

[0075] Carbon fibers with a single filament diameter of 20 μm and an aspect ratio of 20 were placed in a sealed vacuum reactor. The reactor was then evacuated and the air in the reactor was replaced with nitrogen three times. A fluorine / nitrogen mixture with a volume ratio of 1:1 was then introduced into the vacuum reactor. The fluorination temperature was controlled at 200℃ and the time was controlled at 1 hour to make the fluorine content of the fluorinated carbon fiber 2%. After the reaction was completed, the reaction gas in the reactor was replaced with nitrogen several times before the fluorinated carbon fiber was removed.

[0076] Polyimide fibers with a monofilament diameter of 20 μm and an aspect ratio of 20 were placed in a sealed vacuum reactor. The reactor was then evacuated and the air in the reactor was replaced with nitrogen three times. A mixture of fluorine and nitrogen in a volume ratio of 1:1 was then introduced into the vacuum reactor. The fluorination temperature was controlled at 280℃ and the fluorination time was 1.5 h to make the fluorinated carbon fiber have a fluorine content of 2%. After the reaction was completed, the reaction gas in the reactor was replaced with nitrogen several times before the fluorinated polyimide fibers were removed.

[0077] The preparation of modified polytetrafluoroethylene and boron fluoride nitride is the same as in Example 1.

[0078] 100 parts of modified polytetrafluoroethylene, 10 parts of fluorinated carbon fiber, 5 parts of fluorinated polyimide fiber and 5 parts of fluorinated boron nitride were added to a mixer and mixed for 30 minutes. The mixture was then internally mixed in a mixer at 320°C, and then molded at -5°C and 30MPa. Finally, it was sintered at 360°C for 12 hours to obtain the modified PTFE material.

[0079] Comparative Example 1

[0080] Diisopropyl peroxide was added to the tetrafluoroethylene body at a mass of 0.1% of the total mass of the mixed monomers, and the polymerization reaction was carried out at 70°C and 2 MPa for 5 h to obtain polytetrafluoroethylene.

[0081] The preparation of fluorinated carbon fiber, fluorinated polyimide fiber and fluorinated boron nitride is the same as in Example 1.

[0082] 100 parts of polytetrafluoroethylene, 15 parts of fluorinated carbon fiber, 10 parts of fluorinated polyimide fiber and 5 parts of fluorinated boron nitride were added to a mixer and mixed for 30 minutes. The mixture was then internally mixed in a mixer at 330°C, and then molded at 20°C and 20MPa. Finally, it was sintered at 360°C for 10 hours to obtain PTFE material.

[0083] Comparative Example 2

[0084] The preparation of modified polytetrafluoroethylene and boron fluoride nitride is the same as in Example 1.

[0085] Take 100 parts of modified polytetrafluoroethylene, 15 parts of carbon fiber (monofilament diameter 20μm, aspect ratio 20), and fluorinated polyimide fiber (monofilament diameter 20μm, aspect ratio 20).

[0086] 10 parts of fluorinated boron nitride and 5 parts of boron fluoride were added to a mixer and mixed for 30 minutes. The mixture was then internally mixed at 330°C in a mixer, and then molded at 20°C and 20MPa. Finally, it was sintered at 360°C for 10 hours to obtain PTFE material.

[0087] Comparative Example 3

[0088] The preparation of modified polytetrafluoroethylene, fluorinated carbon fiber and fluorinated boron nitride is the same as in Example 1.

[0089] 100 parts of modified polytetrafluoroethylene, 15 parts of fluorinated carbon fiber and 5 parts of fluorinated boron nitride were added to a mixer and mixed for 30 minutes. The mixture was then internally mixed in a mixer at 330°C, and then molded at 20°C and 20MPa. Finally, it was sintered at 360°C for 10 hours to obtain PTFE material.

[0090] Comparative Example 4

[0091] The preparation of modified polytetrafluoroethylene, fluorinated polyimide fiber and fluorinated boron nitride is the same as in Example 1.

[0092] 100 parts of modified polytetrafluoroethylene, 10 parts of fluorinated polyimide fiber and 5 parts of fluorinated boron nitride were added to a mixer and mixed for 30 minutes. The mixture was then internally mixed in a mixer at 330°C, and then molded at 20°C and 20MPa. Finally, it was sintered at 360°C for 10 hours to obtain PTFE material.

[0093] Comparative Example 5

[0094] The preparation of modified polytetrafluoroethylene, fluorinated carbon fiber and fluorinated polyimide fiber is the same as in Example 1.

[0095] 100 parts of modified polytetrafluoroethylene, 15 parts of fluorinated carbon fiber, 10 parts of fluorinated polyimide fiber and 5 parts of boron nitride were added to a mixer and mixed for 30 minutes. The mixture was then internally mixed in a mixer at 330°C, and then molded at 20°C and 20MPa. Finally, it was sintered at 360°C for 10 hours to obtain PTFE material.

[0096] The mechanical properties of the modified PTFE materials obtained in Examples 1-11 and the PTFE materials obtained in Comparative Examples 1-5 were tested. The tensile strength and elongation at break were determined according to GB / T 1040-2018, the flexural strength was determined according to GB / T 9341-2008, and the notched impact strength was determined according to GB / T1043-2008. The results are shown in Table 1.

[0097] Table 1

[0098]

[0099]

[0100] As shown in Table 1, the modified PTFE material prepared by this invention exhibits significant improvements in tensile strength, elongation at break, flexural strength, and notched impact strength. The tensile strength is not less than 200 MPa, the elongation at break is 200%–450%, the flexural strength is not less than 300 MPa, and the notched impact strength is not less than 3 kJ·m. -2Introducing perfluoro-2-butene and perfluoroalkyl vinyl ethers into PTFE helps to break the linear, unbranched, symmetrical structure of PTFE, reduce its melt viscosity, and improve its processability. Comparing Examples 1-4 and Comparative Example 1, it is evident that the perfluoroalkyl side chains introduced by perfluoro-2-butene further enhance the mechanical properties of PTFE. The ether bonds contained in the perfluoroalkyl vinyl ethers can, to some extent, form hydrogen bonds with the NH groups in the polyimide, enhancing the compatibility between the modified PTFE and the polyimide fibers. Comparing Examples 1, 11, and Comparative Example 2, it is clear that the degree of fluorination of the fluorinated carbon fibers and fluorinated polyimide fibers affects the compatibility between the modified PTFE and the fibers. Direct use of carbon fibers and polyimide fibers results in poor compatibility with the modified PTFE, affecting the mechanical strength of the PTFE material. Comparing Examples 1, 5, and 6 with Comparative Examples 3 and 4, it is evident that the mechanical strength of the modified PTFE material increases with increasing fiber content. Fluorinated carbon fiber itself possesses excellent mechanical strength, while fluorinated polyimide fiber exhibits superior compatibility with modified PTFE. The combined use of both further enhances the mechanical properties of the modified PTFE. Fluorination improves the compatibility of fibers and two-dimensional inorganic fillers with PTFE, forming a reinforcing network within the PTFE and effectively improving the mechanical properties of the modified PTFE material.

[0101] The modified PTFE materials obtained in Examples 1-11 and the PTFE materials obtained in Comparative Examples 1-5 were subjected to stability tests. After being placed in a 20% sulfuric acid or sodium hydroxide solution for 70 hours, the change rates of tensile strength and elongation at break were calculated. The results are shown in Table 2.

[0102] Table 2

[0103]

[0104]

[0105] As shown in Table 2, the modified PTFE material prepared by this invention exhibits excellent resistance to acid and alkali corrosion, maintaining good tensile strength and elongation at break under acid and alkali conditions, and has a long service life. For example, under acidic conditions, the change rate of tensile strength is no higher than 5%, and the change rate of elongation at break is no higher than 5%. Under alkaline conditions, the change rate of tensile strength is no higher than 8%, and the change rate of elongation at break is no higher than 8%. It is worth noting that with the increase of the content of perfluoroalkyl vinyl ether and perfluoro-2-butene, the acid and alkali resistance of the modified PTFE material decreases. Unfluorinated carbon fibers and polyimide fibers have poor compatibility with PTFE and weak acid and alkali resistance, resulting in a significant decrease in the acid and alkali resistance of Comparative Example 2 compared to Example 1.

[0106] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A modified PTFE material, characterized in that, By mass parts, it includes the following components: 100 parts modified polytetrafluoroethylene, 10-20 parts fluorinated carbon fiber, 5-10 parts fluorinated polyimide fiber and 5-10 parts fluorinated inorganic filler. The modified polytetrafluoroethylene is copolymerized from tetrafluoroethylene, perfluoro-2-butene, and perfluoroalkyl vinyl ether; The molar ratio of tetrafluoroethylene, perfluoro-2-butene, and perfluoroalkyl vinyl ether is 1:(0.1–0.2):(0.1–0.2); The perfluoroalkyl vinyl ether includes at least one of perfluoromethyl vinyl ether, perfluoroethyl vinyl ether, or perfluoropropyl vinyl ether; The fluorinated carbon fiber has a fluorine content of 2% to 5%, a single filament diameter of 10 to 20 μm, and an aspect ratio of 10 to 30. The fluorinated polyimide fiber has a fluorine content of 2% to 5%, a single filament diameter of 10 to 20 μm, and an aspect ratio of 10 to 30. The fluorinated inorganic filler includes at least one of fluorinated carbon nitride, fluorinated boron nitride, or fluorinated graphite.

2. The modified PTFE material as described in claim 1, characterized in that, The mass ratio of the fluorinated carbon fiber to the fluorinated polyimide fiber is (1-2):

1.

3. A method for preparing the modified PTFE material as described in any one of claims 1 to 2, characterized in that, Includes the following steps: Modified polytetrafluoroethylene, fluorinated carbon fiber, fluorinated polyimide fiber and fluorinated inorganic filler are mixed and then kneaded, followed by low-temperature molding and high-temperature sintering to obtain modified PTFE material.

4. The preparation method according to claim 3, characterized in that, It also includes a method for preparing modified polytetrafluoroethylene, comprising the following steps: Tetrafluoroethylene, perfluoro-2-butene, perfluoroalkyl vinyl ether, and an initiator are mixed and polymerized to obtain modified polytetrafluoroethylene.

5. The application of the modified PTFE material as described in any one of claims 1 to 2 in a wind-bag pump, characterized in that, The application includes the manufacture of wind bags.

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