Sulfonated paek resin, sulfonated paek sized ptf fiber, self-lubricating gasket and methods of making same

Abstract

This invention relates to the field of self-lubricating materials, and particularly to a sulfonated PAEK resin, sulfonated PAEK-sized PTFE fibers, a self-lubricating gasket, and a method for preparing the same. The sulfonated PAEK resin, by weight, comprises 50-100 parts of sulfonated PAEK powder and 5-10 parts of lubricating additives. The sulfonated PAEK powder comprises 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, potassium 2,5-dihydroxybenzenesulfonate, 4,4'-difluorobenzophenone, and a catalyst. The sulfonated PAEK resin of this invention, through the use of sulfonated PAEK powder and lubricating additives, increases the strength and lubricity of PTFE fibers, effectively compensating for the insufficient lubrication and low strength of pure PTFE fibers.

Description

Technical Field

[0001] This invention relates to the field of self-lubricating materials, and particularly to a sulfonated PAEK resin, sulfonated PAEK sized PTFE fiber, a self-lubricating gasket, and a method for preparing the same. Background Technology

[0002] Self-lubricating fabric gaskets are typically made by impregnating PTFE or aramid fiber fabrics with phenolic or epoxy resins. PTFE fibers primarily provide lubrication, while aramid fibers enhance wear resistance, and the impregnating resin provides bonding, fixation, and load-bearing functions. In recent years, researchers have implemented various modification methods to further improve the performance of self-lubricating gaskets. Due to the inherent stability of the fabric, modification is challenging; therefore, the most widespread modification method is to enhance the performance of the phenolic resin, including physical blending and chemical grafting to introduce microcapsules, carbon fibers, nanomaterials, and two-dimensional materials, thereby improving the core tribological and mechanical properties of the gasket. However, phenolic resin modification has certain drawbacks, such as the difficulty in uniformly dispersing microparticles, often leading to agglomeration, and the insufficient performance of existing gaskets is mainly due to insufficient lubrication and low strength of the PTFE fibers.

[0003] It is evident that existing technologies still need improvement and enhancement. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a sulfonated PAEK resin, sulfonated PAEK sized PTFE fiber, a self-lubricating gasket and its preparation method, with the aim of improving the lubrication performance and mechanical properties of PTFE fiber.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] The first aspect of the present invention provides a sulfonated PAEK resin, wherein the raw materials for its preparation, by weight, include: 50 to 100 parts of sulfonated PAEK powder and 5 to 10 parts of lubricating additive; the raw materials for preparing the sulfonated PAEK powder include: 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, potassium 2,5-dihydroxybenzenesulfonate, 4,4'-difluorobenzophenone and a catalyst.

[0007] The sulfonated PAEK resin wherein the molar ratio of 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, potassium 2,5-dihydroxybenzenesulfonate, 4,4'-difluorobenzophenone and the catalyst is (60-80):(20-40):(99-101):(235-245).

[0008] The sulfonated PAEK resin wherein the lubricating additive is selected from at least one of silicon shell microcapsules, nano-PTFE, graphene, and nano-copper powder.

[0009] The sulfonated PAEK resin, wherein the method for preparing the sulfonated PAEK powder includes the following steps:

[0010] 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, potassium 2,5-dihydroxybenzenesulfonate, and 4,4'-difluorobenzophenone were added sequentially to the reactor as reaction monomers, potassium carbonate was used as a catalyst, xylene was added as a dehydrating agent, and dimethyl sulfoxide was added as a solvent.

[0011] Under inert gas protection, the reaction system is heated to 155–160°C and reacted at a constant temperature for 120–140 minutes to achieve the initial polymerization of the monomer; then the temperature is raised to 185–190°C and the reaction is continued at this temperature for 72 hours to obtain sulfonated PAEK.

[0012] The PAEK powder was obtained by low-temperature precipitation, washing to remove solvent, pulverizing, and drying.

[0013] A second aspect of the present invention provides a method for preparing sulfonated PAEK resin, for preparing the sulfonated PAEK resin as described above, comprising the following steps:

[0014] Take fully dried sulfonated PAEK powder and lubricating additives according to the formula and place them in a reactor. Add N-methylpyrrolidone, slowly heat to 80-100°C, and continue stirring until the sulfonated PAEK powder gradually dissolves. The resulting brownish-yellow viscous solution is the sulfonated PAEK resin.

[0015] A third aspect of the present invention provides sulfonated PAEK sized PTFE fibers, comprising PTFE fibers and the sulfonated PAEK resin as described above cured on the PTFE fibers.

[0016] The sulfonated PAEK-sized PTFE fiber is prepared by the following steps:

[0017] To prepare PTFE fiber bundles, the PTFE fiber bundles were immersed in sulfonated PAEK resin slurry for 1–3 minutes.

[0018] Excess sulfonated PAEK resin sizing solution is filtered off, and the mixture is sintered at a high temperature of 340–380°C to simultaneously cure PTFE and sulfonated PAEK, thereby obtaining the sulfonated PAEK sized PTFE fiber.

[0019] A fourth aspect of the present invention provides a self-lubricating pad, the raw materials for which include: phenolic resin and fabric, wherein the fibers used in the weaving of the fabric include sulfonated PAEK sized PTFE fibers as described above.

[0020] The fifth aspect of the present invention provides a method for preparing a self-lubricating gasket, for preparing the self-lubricating gasket as described above, comprising the following steps:

[0021] After diluting the phenolic resin to a continuously flowing state using a diluent, the fabric is immersed in the phenolic resin. After thorough impregnation, excess phenolic resin is removed from the fabric surface, and the fabric is cured to obtain a self-lubricating pad.

[0022] The method for preparing the self-lubricating gasket, wherein the diluent is prepared from ethyl acetate and ethanol.

[0023] Beneficial effects: This invention provides a sulfonated PAEK resin, which is composed of sulfonated PAEK powder and lubricating additives. The sulfonated PAEK powder is prepared using 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, potassium 2,5-dihydroxybenzenesulfonate, and 4,4'-difluorobenzophenone as monomers, which can effectively improve the lubrication effect and strength of PTFE fibers. Attached Figure Description

[0024] Figure 1 Photos of PTFE fibers and PTFE fibers sized with sulfonated PAEK. Detailed Implementation

[0025] This invention provides a sulfonated PAEK resin, sulfonated PAEK sized PTFE fiber, a self-lubricating gasket, and a method for preparing the same. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0026] The first aspect of this invention provides a sulfonated PAEK resin, the raw materials for which, by weight, are: 50-100 parts of sulfonated PAEK powder and 5-10 parts of lubricating additive; the raw materials for preparing the sulfonated PAEK powder include: 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, potassium 2,5-dihydroxybenzenesulfonate, 4,4'-difluorobenzophenone, and a catalyst. Compared with the prior art, in the raw materials for preparing the sulfonated PAEK powder of this invention, 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl is used to replace bisphenol A, thereby improving the strength of the obtained sulfonated PAEK powder. In the sulfonated PAEK resin, the lubricating additive plays a role in friction lubrication. Because the lubricating additive is incorporated into the resin, it is continuously exposed during friction, thus providing continuous lubrication.

[0027] Preferably, in the raw materials for preparing the sulfonated PAEK powder, the molar ratio of 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, potassium 2,5-dihydroxybenzenesulfonate, 4,4'-difluorobenzophenone and the catalyst is (60-80):(20-40):(99-101):(235-245).

[0028] Preferably, the lubricating additive is selected from at least one of silicon microcapsules, nano-PTFE, graphene, and nano-copper powder.

[0029] Preferably, the method for preparing the sulfonated PAEK powder includes the following steps:

[0030] 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, potassium 2,5-dihydroxybenzenesulfonate, and 4,4'-difluorobenzophenone were added sequentially to the reactor as reaction monomers, potassium carbonate was used as a catalyst, xylene was added as a dehydrating agent, and dimethyl sulfoxide was added as a solvent.

[0031] Under inert gas protection, the reaction system is heated to 155–160°C and reacted at a constant temperature for 120–140 minutes to achieve the initial polymerization of the monomer; then the temperature is raised to 185–190°C and the reaction is continued at this temperature for 72 hours to obtain sulfonated PAEK polymer.

[0032] After the reaction is complete, the reaction product is quickly poured into ice water to precipitate the polymer, resulting in a grayish-white blocky solid. The crude product is then soaked in a 50-60% ethanol aqueous solution for 96 hours to fully extract the residual solvent. Subsequently, the solid is pulverized into powder and transferred to a washing vessel. It is washed 8-10 times with a 20-30% ethanol aqueous solution at 50-60°C, each time for 8-10 hours, to effectively remove residual solvent, unreacted monomers, and inorganic salt impurities. After washing, solid-liquid separation is performed using a filtration device. The resulting powder is then dried in an 80-100°C forced-air drying oven for 90-100 hours to finally obtain pure sulfonated PAEK powder.

[0033] The above preparation method can produce sulfonated PAEK powder with controllable sulfonation degree and molecular weight, ensuring the strength and application effect of sulfonated PAEK.

[0034] A second aspect of the present invention provides a method for preparing sulfonated PAEK resin, which is used to prepare the sulfonated PAEK resin as described above, comprising the following steps:

[0035] Take fully dried sulfonated PAEK powder and lubricating additives according to the formula and place them in a reactor. Add N-methylpyrrolidone, slowly heat to 80-100°C, and continue stirring until the sulfonated PAEK powder gradually dissolves. The resulting brownish-yellow viscous solution is the sulfonated PAEK resin.

[0036] A third aspect of the present invention provides sulfonated PAEK sized PTFE fibers, comprising PTFE fibers and the sulfonated PAEK resin as described above cured on the PTFE fibers. Figure 1 a is PTFE fiber. Figure 1 b represents sulfonated PAEK-sized PTFE fiber. PTFE fibers treated with sulfonated PAEK sizing exhibit significantly improved strength and lubrication.

[0037] The sulfonated PAEK-sized PTFE fiber is prepared by the following steps:

[0038] To prepare PTFE fiber bundles, the PTFE fiber bundles were immersed in sulfonated PAEK resin slurry for 1–3 minutes.

[0039] Excess sulfonated PAEK resin sizing solution is filtered off, and the mixture is sintered at a high temperature of 340–380°C to simultaneously cure PTFE and sulfonated PAEK, thereby obtaining the sulfonated PAEK sized PTFE fiber.

[0040] In one specific embodiment, the method for preparing sulfonated PAEK-sized PTFE fibers comprises the following steps:

[0041] (1) Take 340g of deionized water and 16g of sodium alginate, stir in a 70℃ water bath, and prepare a sodium alginate (SA) solution with a mass fraction of 4.5%.

[0042] (2) Weigh 240g of concentrated PTFE dispersion (60% solid content) according to the ratio of SA:PTFE=1:9 (mass ratio), pour it into the prepared sodium alginate solution, add 5-6 drops of modified silicone oil defoamer, stir for 6h to make PTFE uniformly dispersed in sodium alginate solution to obtain spinning solution, let the spinning solution stand overnight under vacuum to remove bubbles, and obtain PTFE spinning solution;

[0043] (3) Dissolve 200g of anhydrous calcium chloride in 10kg of deionized water to prepare a 2% calcium chloride solution as a coagulation bath, and use 10kg of deionized water as a washing bath, and prepare sulfonated PAEK resin as a sizing solution.

[0044] (4) The wet spinning steps are as follows: PTFE spinning solution flows through the reducer cavity and is extruded from the spinneret. The speed of the reducer is 18-20 r / min. The spinneret has 40 holes, and the diameter of each hole is 70µm. The spinning solution flows through the spinneret into the coagulation bath and is formed. During this process, sodium alginate reacts rapidly with calcium chloride to form calcium alginate. Then, the residual calcium chloride solution on the fiber surface is washed away by the cleaning bath. The fiber is then further heated by the heating roller at 100-150℃ to remove excess moisture from the surface and obtain PTFE fiber bundles.

[0045] (5) Next, the PTFE fiber bundle is immersed in the sulfonated PAEK resin sizing solution for 1 to 3 minutes to ensure that the sulfonated PAEK resin sizing solution completely immerses the PTFE fiber bundle. After sizing, the PTFE fiber bundle is pulled in the air for 1 to 3 minutes to filter out excess sizing solution. Finally, the PTFE fiber bundle is put into the fiber sintering machine for high-temperature sintering at a temperature of 340 to 380°C to remove the sodium alginate carrier in the PTFE fiber and simultaneously complete the curing of PTFE and sulfonated PAEK to obtain sulfonated PAEK sized PTFE fiber.

[0046] A fourth aspect of the present invention provides a self-lubricating pad, the raw materials for which include: phenolic resin and fabric, wherein the fibers used in the weaving of the fabric include sulfonated PAEK sized PTFE fibers as described above.

[0047] The specific method for weaving the fabric can be described in the following steps: using a digital sample doubling machine, two strands of sulfonated PAEK sized PTFE fibers are doubled at a doubling speed of 90 m / min; then, using a digital sample doubling twisting machine, with a spindle speed set to 2000 r / min and a twist set to 10 T / 10 cm, the fibers after doubling are twisted; finally, using a fully automatic rapier weaving machine, with sulfonated PAEK sized PTFE fibers for the weft and aramid fibers for the warp, plain weave, twill weave, satin weave, and other structures are woven to obtain the fabric.

[0048] The method for preparing the self-lubricating gasket includes the following steps:

[0049] After diluting the phenolic resin to a continuously flowing state using a diluent, the fabric is immersed in the phenolic resin. After thorough impregnation, excess phenolic resin is removed from the fabric surface, and the fabric is cured to obtain a self-lubricating pad.

[0050] In one specific embodiment, the self-lubricating pad is prepared as follows: ethyl acetate and ethanol are mixed in a mass ratio of 1:1 to form a diluent. Pure phenolic resin is diluted to a continuously flowing state using the diluent. The fabric is then immersed in the phenolic resin. Preferably, the mass ratio of the diluent to the pure phenolic resin is 1:2. After immersion for 30 minutes, excess phenolic resin is removed from the fabric surface. The fabric is then semi-cured at 90°C and 0.8 MPa for 60 minutes to obtain the self-lubricating pad.

[0051] Example 1

[0052] A self-lubricating gasket, the preparation method of which is as follows:

[0053] S1. Preparation of PAEK powder: 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, potassium 2,5-dihydroxybenzenesulfonate, and 4,4'-difluorobenzophenone are added sequentially to a reactor as reactants, potassium carbonate is used as a catalyst, xylene is added as a dehydrating agent, and dimethyl sulfoxide is used as a solvent; the molar ratio of 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, potassium 2,5-dihydroxybenzenesulfonate, 4,4'-difluorobenzophenone, and potassium carbonate is 70:30:100:240;

[0054] Under inert gas protection, the reaction system was heated to 160°C and reacted at a constant temperature for 130 minutes to achieve the initial polymerization of the monomer; then the temperature was raised to 185°C and the reaction was continued at this temperature for 72 hours to obtain sulfonated PAEK polymer.

[0055] After the reaction was completed, the reaction product was quickly poured into ice water to precipitate the polymer, resulting in a grayish-white blocky solid. The crude product was then soaked in a 60% ethanol aqueous solution for 96 hours to fully extract the residual solvent. Subsequently, the solid was pulverized into powder and transferred to a washing vessel. It was washed 10 times with a 30% ethanol aqueous solution at 60°C, each time for 10 hours, to effectively remove residual solvent, unreacted monomers, and inorganic salt impurities. After washing, solid-liquid separation was performed using a filtration device. The resulting powder was dried in a 90°C forced-air drying oven for 90 hours to finally obtain pure sulfonated PAEK powder. The degree of sulfonation of the sulfonated PAEK powder was 30.

[0056] S2. Preparation of sizing solution: Weigh 50g of sulfonated PAEK powder, 5g of silica-shell microcapsules, and 1000 mL of N-methylpyrrolidone (NMP) into a clean three-necked flask, heat and stir at 80°C for 48 hours to form sulfonated PAEK resin sizing solution.

[0057] S3.PTFE spinning solution is processed through spinning, coagulation, washing, sizing, drying, and sintering to obtain sulfonated PAEK sized PTFE fibers.

[0058] S4. After weaving the twill fabric using a fully automatic rapier weaving machine, the fabric is soaked in impregnated phenolic resin and cured to obtain a self-lubricating pad.

[0059] Example 2

[0060] A self-lubricating gasket, the preparation method of which differs from that of Example 1, is as follows: in S2, 50g of prepared sulfonated PAEK powder, 5g of silicone microcapsules, 5g of nano-PTFE, and 1000mL of N-methylpyrrolidone (NMP) are weighed and placed in a clean three-necked flask, heated and stirred at 80°C for 48 hours to form a sulfonated PAEK resin slurry.

[0061] Example 3

[0062] A self-lubricating gasket, the preparation method of which differs from that of Example 1, is as follows: in S2, 50g of prepared sulfonated PAEK powder, 5g of silicon shell microcapsules, 5g of nano copper powder, and 1000mL of N-methylpyrrolidone (NMP) are weighed and placed in a clean three-necked flask, heated and stirred at 80°C for 48 hours to form a sulfonated PAEK resin slurry.

[0063] Example 4

[0064] A self-lubricating gasket, the preparation method of which differs from that of Example 1, is as follows: in S2, 50g of prepared sulfonated PAEK powder, 5g of silicon shell microcapsules, 5g of graphene, and 1000mL of N-methylpyrrolidone (NMP) are weighed and placed in a clean three-necked flask, heated and stirred at 80°C for 48 hours to form a sulfonated PAEK resin slurry.

[0065] Example 5

[0066] A self-lubricating gasket, the preparation method of which differs from that of Example 1, is that in S1, the molar ratio of 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, potassium 2,5-dihydroxybenzenesulfonate, 4,4'-difluorobenzophenone and potassium carbonate is 60:40:100:240; and the degree of sulfonation of the sulfonated PAEK powder is 40.

[0067] Example 6

[0068] A self-lubricating gasket, the preparation method of which differs from that of Example 1, is that in S1, the molar ratio of 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, potassium 2,5-dihydroxybenzenesulfonate, 4,4'-difluorobenzophenone and potassium carbonate is 80:20:100:240; and the degree of sulfonation of the sulfonated PAEK powder is 20.

[0069] Comparative Example 1

[0070] A liner whose preparation method differs from that of Example 1 is that the PTFE fibers are not sized with sulfonated PAEK resin.

[0071] Comparative Example 2

[0072] A self-lubricating gasket, the preparation method of which differs from that of Example 1, uses concentrated sulfuric acid sulfonated PEEK instead of sulfonated PAEK;

[0073] The preparation method of PEEK sulfonated with concentrated sulfuric acid is as follows:

[0074] 50g of polyetheretherketone (PEEK) powder was added to 300 mL of concentrated sulfuric acid and stirred at 60°C until PEEK was completely dissolved, preparing a concentrated sulfuric acid sulfonated PEEK solution. The sulfonated PEEK solution was slowly added to water at 0°C, precipitating sulfonated PEEK solids. The solution was neutralized and washed in an alkaline solution, yielding a mixture containing flocculent solids. The mixture was then filtered, washed with pure water until the pH reached 7, and dried to obtain sulfonated PEEK powder.

[0075] Comparative Example 3

[0076] A self-lubricating gasket, the preparation method of which differs from that of Example 1, is that bisphenol A is used instead of 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl.

[0077] The performance of the gaskets in the above embodiments and comparative examples was tested.

[0078] (1) Mechanical property testing of PTFE fibers:

[0079] The breaking force of PTFE fibers was tested using an electronic single-fiber tensile testing machine (YG005A, Wenzhou Baien Instrument Co., Ltd.). The PTFE fibers were fixed on a fixture with a clamping distance of 10 mm and a tensile speed of 20 mm / min. Five sets of data were collected for each sample, and the average value was calculated. The results are shown in Table 1.

[0080] Table 1

[0081]

[0082] As shown in Table 1, Examples 1-6 all involved sulfonated PAEK-sized PTFE, with breaking strengths ranging from 3.6 to 4.2 N. The difference lay in the composition of the lubricating additives. Comparative Example 1, which was pure PTFE without sulfonated PAEK resin sizing, had a breaking strength of only 2.72 N, indicating that sulfonated PAEK resin sizing effectively improved the strength of PTFE fibers. Comparative Example 2 used concentrated sulfuric acid to sulfonate PEEK, resulting in PTFE fibers with a breaking strength of 3.19 N, significantly higher than pure PTFE. However, due to the uncontrollable degree of sulfonation, uncontrollable molecular weight, and structural damage caused by concentrated sulfuric acid, the PEEK strength was low, thus the strengthening effect was not as good as the prepared PAEK. Comparative Example 3 used bisphenol A instead of the 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl monomer, resulting in a decrease in the stiffness of the synthesized PAEK, and therefore the reinforcing effect was also inferior to the examples.

[0083] (2) Tribological property testing of the pad composite material:

[0084] The prepared fabric pad was subjected to tribological testing using a surface contact resin lubricating material friction performance evaluation tester. The motion mode was rotational sliding, the load was 2000N, the rotation speed was 20rpm, and the test time was 1h. The wear depth after the experiment was measured using a laser profilometer. The results are shown in Table 2.

[0085]

[0086] As shown in Table 1, Comparative Example 1, without sizing treatment, relied solely on PTFE fiber lubrication, and due to its low fiber strength, its coefficient of friction and wear depth were significantly greater than those of Examples 1-6. Comparative Example 2, which used concentrated sulfuric acid sulfonation for PEEK sizing, showed a significant effect; however, the uncontrollable degree of sulfonation and structural damage caused by concentrated sulfuric acid resulted in low PEEK strength, thus its performance was inferior to the examples. Comparative Example 3, by replacing the monomer, resulted in a decrease in rigidity; although it showed a significant reinforcing effect under the same formulation, it was still not as effective as the examples.

[0087] It is understood that those skilled in the art can make equivalent substitutions or modifications to the technical solution and inventive concept of the present invention, and all such substitutions or modifications should fall within the protection scope of the appended claims.

Claims

1. A sulfonated PAEK-sized PTFE fiber, characterized in that, The invention comprises PTFE fibers and sulfonated PAEK resin cured on the PTFE fibers; the sulfonated PAEK resin, by mass parts, comprises 50-100 parts of sulfonated PAEK powder and 5-10 parts of lubricating additives; the sulfonated PAEK powder comprises 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, potassium 2,5-dihydroxybenzenesulfonate, 4,4'-difluorobenzophenone, and a catalyst; the molar ratio of 3,5,3',5'-tetramethyl-4,4'-dihydroxybiphenyl, potassium 2,5-dihydroxybenzenesulfonate, 4,4'-difluorobenzophenone, and the catalyst is (60-80):(20-40):(99-101):(235-245); the lubricating additive is selected from at least one of silicon microcapsules, nano-PTFE, graphene, and nano-copper powder.

2. The sulfonated PAEK-sized PTFE fiber according to claim 1, characterized in that, The preparation method of the sulfonated PAEK powder includes the following steps: 3,5,3',5'-Tetramethyl-4,4'-dihydroxybiphenyl, potassium 2,5-dihydroxybenzenesulfonate, and 4,4'-difluorobenzophenone were added sequentially to the reactor as reaction monomers, potassium carbonate was used as a catalyst, xylene was added as a dehydrating agent, and dimethyl sulfoxide was added as a solvent. Under inert gas protection, the reaction system is heated to 155–160°C and reacted at a constant temperature for 120–140 minutes to achieve the initial polymerization of the monomer; then the temperature is raised to 185–190°C and the reaction is continued at this temperature for 72 hours to obtain sulfonated PAEK. The PAEK powder was obtained by low-temperature precipitation, washing to remove solvent, pulverizing, and drying.

3. The sulfonated PAEK-sized PTFE fiber according to claim 1, characterized in that, Its preparation method includes the following steps: To prepare PTFE fiber bundles, the PTFE fiber bundles were impregnated in sulfonated PAEK resin for 1–3 minutes. Excess sulfonated PAEK resin is filtered out, and the mixture is sintered at a high temperature of 340–380°C to simultaneously cure PTFE and sulfonated PAEK, thereby obtaining the sulfonated PAEK-sized PTFE fiber.

4. A self-lubricating gasket, characterized in that, The raw materials for its preparation include phenolic resin and fabric, wherein the fibers used in the weaving of the fabric include sulfonated PAEK sized PTFE fibers as described in any one of claims 1-3.

5. A method for preparing a self-lubricating gasket, used to prepare the self-lubricating gasket of claim 4, characterized in that, Includes the following steps: After diluting the phenolic resin to a continuously flowing state using a diluent, the fabric is immersed in the phenolic resin. After thorough impregnation, excess phenolic resin is removed from the fabric surface, and the fabric is cured to obtain a self-lubricating pad.

6. The method for preparing a self-lubricating gasket according to claim 5, characterized in that, The diluent was prepared from ethyl acetate and ethanol.

Images