Sealing material and decolorizing kettle applied to intermediate synthesis

Abstract

The invention relates to a sealing material and a decoloring kettle applied to intermediate synthesis, and belongs to the technical field of composite materials. The compatilizer with a phosphoric acid structure is prepared, the compatilizer is used for treating and modifying the aluminum filler, a quaternary ammonium salt structure and a long-chain alkyl structure are introduced to the surface of the modified aluminum filler, the quaternary ammonium salt structure can generate electrostatic attraction with sulfonic acid groups in perfluorosulfonic acid resin, and the long-chain alkyl structure can generate long-chain alkyl groups in the perfluorosulfonic acid resin; the long-chain perfluoroalkyl structure can be entangled with a polytetrafluoroethylene resin molecular chain, and the two effects are synergistic, so that the binding capacity of the aluminum filler and the polytetrafluoroethylene-perfluorosulfonic acid resin composite material is effectively improved, and a polytetrafluoroethylene phase and a perfluorosulfonic acid resin phase can be bridged; the overall mechanical property of the composite material is effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, specifically relating to a sealing material and its application in a decolorizing reactor for intermediate synthesis. Background Technology

[0002] In chemical production processes, the decolorization reactor is one of the key pieces of equipment in the intermediate synthesis process. Because the intermediate decolorization reactor needs to operate in a high-temperature environment and frequently come into contact with highly corrosive solvents, it has extremely high requirements for the inertness of the sealing material.

[0003] Polytetrafluoroethylene (PTFE) resin has extremely high inertness and is almost insoluble in any solvent, making it an ideal material for preparing sealing materials. However, due to its poor abrasion resistance, and the frequent addition of activated carbon abrasives in decolorization reactors, the PTFE resin may be worn down under high stirring speeds, affecting the purity of intermediates. Furthermore, under the continuous pressure of bolts, PTFE resin will undergo slow plastic deformation and flow. This means that the applied bolt preload will gradually thin the gasket, causing it to flow into the flange's external and internal voids, resulting in a decrease in sealing stress within the decolorization reactor. To address these technical deficiencies, this invention provides a sealing material and its application in a decolorization reactor for intermediate synthesis. Summary of the Invention

[0004] The purpose of this invention is to provide a sealing material and its application in a decolorizing reactor for intermediate synthesis, in order to solve the problems mentioned in the background art.

[0005] The objective of this invention can be achieved through the following technical solutions: A sealing material comprising the following raw materials in parts by weight: 60-75 parts polytetrafluoroethylene resin, 10-20 parts perfluorosulfonic acid resin, 15-20 parts filler, and 3-4 parts compatibilizer.

[0006] Furthermore, the packing material is an aluminum-based packing material.

[0007] Furthermore, the compatibilizer has a phosphoric acid structure, which enables it to stably bind with aluminum-based fillers through coordination bonds, and the compatibilizer can be prepared by the following steps: S1. Intermediate 1 is obtained by Michael addition reaction of fluoroolefins with diethanolamine; S2. Intermediate 2 is obtained by reacting intermediate 1 with a haloalkane as a quaternary ammonium salt. S3. A compatibilizer is obtained by phosphorylation of intermediate 2 with phosphorus pentoxide.

[0008] Furthermore, the fluoroolefin has the following structure: CF3 (CF2) n CH=CH2, where n is a natural number greater than 6 and less than 12.

[0009] Furthermore, the haloalkane has the following structure: CH3(CH2) n X, where n is a natural number greater than 0 and less than 4, and X is one of Br or Cl.

[0010] Furthermore, the sealing material can be made by the following steps: Step 1: After thermally activating the filler, remove surface impurities by acid washing. Then mix the acid-washed filler, compatibilizer, and organic solvent and ultrasonically treat it. After ultrasonic treatment, filter out the solid, wash it with deionized water, and dry it to obtain the modified filler. Step 2: Add polytetrafluoroethylene resin, perfluorosulfonic acid resin and modified filler to a high-speed mixer and mix evenly. Then let it stand to mature to obtain a preform. Then mold the preform to obtain a green embryo. Finally, sinter the green embryo and cool it to obtain the sealing material.

[0011] Furthermore, the organic solvent is one of N,N-dimethylformamide and N,N-dimethylacetamide.

[0012] Furthermore, the conditions for thermal activation are heat treatment at 250–350°C for 1–2 hours and ultrasonic treatment for 25–45 minutes.

[0013] Furthermore, the compression molding conditions are to press for 3 to 5 minutes under a pressure of 25 to 35 MPa.

[0014] Furthermore, the sintering conditions are as follows: preheating at 280–320°C for 30–60 minutes, followed by raising the temperature to 355–375°C and firing at 355–375°C for 2–3 hours.

[0015] A sealing material is used in a decolorizing reactor for intermediate synthesis.

[0016] The beneficial effects of this invention are: This invention modifies polytetrafluoroethylene (PTFE) material by adding perfluorosulfonic acid resin. Perfluorosulfonic acid resin has good elasticity and can effectively improve the deformation recovery ability of PTFE-perfluorosulfonic acid resin composite material under continuous pressure after blending. It can maintain the required sealing pressure for a longer time and effectively reduce the risk of shutdown caused by stress relaxation.

[0017] This invention prepares a compatibilizer with a phosphoric acid structure and uses it to modify aluminum-based fillers. Positively charged quaternary ammonium salt structures and long-chain perfluoroalkyl structures are introduced onto the surface of the aluminum-based fillers. The positively charged quaternary ammonium salt structures can electrostatically attract the sulfonic acid groups in the perfluorosulfonic acid resin, while the long-chain perfluoroalkyl structures can entangle with the polytetrafluoroethylene resin molecular chains. These two effects work synergistically to effectively improve the compatibility between the aluminum-based fillers and the polytetrafluoroethylene-perfluorosulfonic acid resin composite material, and enhance the dispersibility and binding ability of the aluminum-based fillers in the polytetrafluoroethylene-perfluorosulfonic acid resin composite material.

[0018] This invention effectively improves the wear resistance of polytetrafluoroethylene-perfluorosulfonic acid resin composites by adding aluminum-based fillers. In addition, the aluminum-based fillers treated with compatibilizers can effectively bridge the polytetrafluoroethylene phase and the perfluorosulfonic acid resin phase, thereby improving the overall mechanical properties of the polytetrafluoroethylene-perfluorosulfonic acid resin composites. Attached Figure Description

[0019] Figure 1 The image shows the infrared spectrum of the compatibilizer obtained in Example 1. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] The raw materials used in this invention are not particularly restricted in terms of their source; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0022] Example 1

[0023] A sealing material comprising the following raw materials in parts by weight: 75 parts polytetrafluoroethylene resin, 10 parts perfluorosulfonic acid resin, 15 parts alumina filler, and 3 parts compatibilizer.

[0024] The compatibilizer is prepared by the following steps: S1. By mass fraction, 4.46 parts of 1H,1H,2H-perfluoro-1-decene, 1.05 parts of diethanolamine, 0.31 parts of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, and 15 parts of N,N-dimethylformamide were mixed in a three-necked flask equipped with a reflux condenser and a magnetic stirrer. After turning on the magnetic stirrer, the mixture was reacted at 85°C for 4 hours. After the reaction was completed, the reaction solution was cooled to room temperature and poured into deionized water. After extraction with dichloromethane, the solvent was removed by rotary evaporation to obtain intermediate 1. S2. By mass, 4.41 parts of intermediate 1, 0.93 parts of 1-chlorobutane, and 10 parts of N,N-dimethylformamide were mixed in a three-necked flask equipped with a reflux condenser and a magnetic stirrer. After turning on the magnetic stirrer, the mixture was reacted at 65°C for 12 hours. After the reaction was completed, the reaction solution was cooled to room temperature and poured into petroleum ether to precipitate. After filtering to separate the solid, it was washed with anhydrous ethanol and deionized water and dried to obtain intermediate 2. S3. By mass, 4.12 parts of intermediate 2 and 15 parts of N,N-dimethylformamide were mixed in a three-necked flask equipped with a reflux condenser and a magnetic stirrer. After turning on the magnetic stirrer, the system temperature was raised to 45°C. Then, 0.78 parts of phosphorus pentoxide were added to the system in three batches, with each batch containing 0.26 parts and the interval between each batch being 30 min. After adding all the phosphorus pentoxide, the temperature was maintained at 45°C and the reaction was continued for 30 min. Then, 0.4 parts of deionized water were added to the system, and the system temperature was raised to 60°C. The reaction was continued at 60°C for 30 min. After the reaction was completed, the reaction solution was cooled to room temperature and poured into petroleum ether to precipitate. After filtering to separate the solid, it was washed with anhydrous ethanol and deionized water to obtain the compatibilizer.

[0025] The above raw materials are processed into a sealing material through the following steps: Step 1: According to the mass fraction, 15 parts of alumina filler were heat-treated at 250℃ for 2 hours, and then surface impurities were removed by acid washing. After that, the acid-washed alumina filler, 3 parts of compatibilizer, and 75 parts of N,N-dimethylformamide were mixed and ultrasonically treated for 25 minutes. After ultrasonic treatment, the solid was filtered out, washed with deionized water, and dried to obtain modified alumina filler. Step 2: By weight, add 75 parts of polytetrafluoroethylene resin, 10 parts of perfluorosulfonic acid resin, and 15.7 parts of modified alumina filler to a high-speed mixer and mix evenly. After standing and curing, a preform is obtained. The preform is then pressed under a pressure of 25 MPa for 5 minutes to obtain a green compact. Finally, the green compact is preheated at a temperature of 280℃ for 60 minutes. Then, the temperature is raised to 355℃ and fired at 355℃ for 3 hours. After cooling, the sealing material is obtained.

[0026] A sealing material is used in a decolorizing reactor for intermediate synthesis.

[0027] Example 2

[0028] A sealing material comprising the following raw materials in parts by weight: 67.5 parts polytetrafluoroethylene resin, 15 parts perfluorosulfonic acid resin, 17.5 parts aluminum nitride filler, and 3.5 parts compatibilizer.

[0029] The compatibilizer is prepared by the following steps: S1. By mass fraction, 5.46 parts of 1H,1H,2H-perfluoro-1-dodecene, 1.05 parts of diethanolamine, 0.38 parts of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, and 20 parts of N,N-dimethylformamide were mixed in a three-necked flask equipped with a reflux condenser and a magnetic stirrer. After turning on the magnetic stirrer, the mixture was reacted at 100°C for 3.5 h. After the reaction was completed, the reaction solution was cooled to room temperature and poured into deionized water. After extraction with dichloromethane, the solvent was removed by rotary evaporation to obtain intermediate 1. S2. By mass, 5.21 parts of intermediate 1, 0.78 parts of 1-chloropropane, and 15 parts of N,N-dimethylformamide were mixed in a three-necked flask equipped with a reflux condenser and a magnetic stirrer. After turning on the magnetic stirrer, the mixture was reacted at 85°C for 8 hours. After the reaction was completed, the reaction solution was cooled to room temperature and poured into petroleum ether to precipitate. After filtering to separate the solid, the mixture was washed with anhydrous ethanol and deionized water and dried to obtain intermediate 2. S3. By mass, 4.67 parts of intermediate 2 and 17.5 parts of N,N-dimethylformamide were mixed in a three-necked flask equipped with a reflux condenser and a magnetic stirrer. After turning on the magnetic stirrer, the system temperature was raised to 50°C. Then, 0.78 parts of phosphorus pentoxide were added to the system in three batches, with each batch containing 0.26 parts and the interval between each batch being 30 min. After adding all the phosphorus pentoxide, the temperature was maintained at 50°C and the reaction was continued for 30 min. Then, 0.5 parts of deionized water were added to the system, and the system temperature was raised to 65°C. The reaction was continued at 65°C for 30 min. After the reaction was completed, the reaction solution was cooled to room temperature and poured into petroleum ether to precipitate. After filtering to separate the solid, it was washed with anhydrous ethanol and deionized water to obtain the compatibilizer.

[0030] The above raw materials are processed into a sealing material through the following steps: Step 1: According to the mass fraction, 17.5 parts of aluminum nitride filler were heat-treated at 300℃ for 1.5h, and then surface impurities were removed by acid washing. Then, the acid-washed aluminum nitride filler, 3.5 parts of compatibilizer, and 87.5 parts of N,N-dimethylformamide were mixed and ultrasonically treated for 35min. After ultrasonic treatment, the solid was filtered out, washed with deionized water, and dried to obtain modified aluminum nitride filler. Step 2: By weight, 67.5 parts of polytetrafluoroethylene resin, 15 parts of perfluorosulfonic acid resin, and 18.4 parts of modified aluminum nitride filler are added to a high-speed mixer and mixed evenly. After standing and curing, a preform is obtained. The preform is then pressed under a pressure of 30 MPa for 4 minutes to obtain a green compact. Finally, the green compact is preheated at 300℃ for 45 minutes, then the temperature is raised to 365℃ and fired at 365℃ for 2.5 hours. After cooling, the sealing material is obtained.

[0031] A sealing material is used in a decolorizing reactor for intermediate synthesis.

[0032] Example 3

[0033] A sealing material comprising the following raw materials in parts by weight: 60 parts polytetrafluoroethylene resin, 20 parts perfluorosulfonic acid resin, 20 parts alumina filler, and 4 parts compatibilizer.

[0034] The compatibilizer is prepared by the following steps: S1. By mass fraction, 6.46 parts of 1H,1H,2H-perfluoro-1-tetradecene, 1.05 parts of diethanolamine, 0.46 parts of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, and 25 parts of N,N-dimethylformamide were mixed in a three-necked flask equipped with a reflux condenser and a magnetic stirrer. After turning on the magnetic stirrer, the mixture was reacted at 115°C for 3 hours. After the reaction was completed, the reaction solution was cooled to room temperature and poured into deionized water. After extraction with dichloromethane, the solvent was removed by rotary evaporation to obtain intermediate 1. S2. By mass, 6.01 parts of intermediate 1, 1.09 parts of bromoethane, and 20 parts of N,N-dimethylformamide were mixed in a three-necked flask equipped with a reflux condenser and a magnetic stirrer. After turning on the magnetic stirrer, the mixture was reacted at 105°C for 6 hours. After the reaction was completed, the reaction solution was cooled to room temperature and poured into petroleum ether to precipitate. After filtering to separate the solid, it was washed with anhydrous ethanol and deionized water and dried to obtain intermediate 2. S3. By mass, 5.51 parts of intermediate 2 and 20 parts of N,N-dimethylformamide were mixed in a three-necked flask equipped with a reflux condenser and a magnetic stirrer. After turning on the magnetic stirrer, the system temperature was raised to 45-55°C. Then, 0.78 parts of phosphorus pentoxide were added to the system in three batches, with each batch containing 0.26 parts and an interval of 30 minutes between each batch. After adding all the phosphorus pentoxide, the temperature was maintained at 55°C and the reaction was continued for 30 minutes. Then, 0.6 parts of deionized water were added to the system, and the system temperature was raised to 70°C. The reaction was continued at 70°C for 30 minutes. After the reaction was completed, the reaction solution was cooled to room temperature and poured into petroleum ether to precipitate. After filtering to separate the solid, it was washed with anhydrous ethanol and deionized water to obtain the compatibilizer.

[0035] The above raw materials are processed into a sealing material through the following steps: Step 1: According to the mass fraction, 20 parts of alumina filler were heat-treated at 350℃ for 1 hour, and then surface impurities were removed by acid washing. After that, the acid-washed alumina filler, 4 parts of compatibilizer and 100 parts of N,N-dimethylformamide were mixed and ultrasonically treated for 45 minutes. After ultrasonic treatment, the solid was filtered out and washed with deionized water and dried to obtain modified alumina filler. Step 2: By weight, add 60 parts of polytetrafluoroethylene resin, 20 parts of perfluorosulfonic acid resin, and 21.2 parts of modified alumina filler to a high-speed mixer and mix evenly. After standing and curing, a preform is obtained. The preform is then pressed at a pressure of 35 MPa for 3 minutes to obtain a green compact. Finally, the green compact is preheated at a temperature of 320℃ for 30 minutes. Then, the temperature is raised to 375℃ and fired at 375℃ for 2 hours. After cooling, the sealing material is obtained.

[0036] A sealing material is used in a decolorizing reactor for intermediate synthesis.

[0037] Comparative Example 1 The difference between this comparative example and Example 2 is that the aluminum nitride abrasive was not prepared and treated with a compatibilizer, while other conditions and preparation steps remained unchanged.

[0038] A sealing material comprising the following raw materials in parts by weight: 67.5 parts polytetrafluoroethylene resin, 15 parts perfluorosulfonic acid resin, and 17.5 parts aluminum nitride filler.

[0039] The above raw materials are processed into a sealing material through the following steps: Step 1: According to the mass fraction, 17.5 parts of aluminum nitride filler were heat-treated at 300℃ for 1.5h, and then pickled to remove surface impurities to obtain pickled aluminum nitride filler. Step 2: By weight, add 67.5 parts of polytetrafluoroethylene resin, 15 parts of perfluorosulfonic acid resin, and 17.5 parts of pickled aluminum nitride filler to a high-speed mixer and mix evenly. After standing and curing, a preform is obtained. The preform is then pressed under a pressure of 30 MPa for 4 minutes to obtain a green compact. Finally, the green compact is preheated at 300℃ for 45 minutes, then the temperature is raised to 365℃ and fired at 365℃ for 2.5 hours. After cooling, the sealing material is obtained.

[0040] Comparative Example 2 The difference between this comparative example and Example 2 is that perfluorosulfonic acid resin is not added when preparing the sealing material, and the amount of aluminum nitride abrasive added is reduced proportionally, while the other raw materials and preparation steps remain unchanged.

[0041] A sealing material comprising the following raw materials in parts by weight: 67.5 parts polytetrafluoroethylene resin, 14.3 parts aluminum nitride filler, and 3.5 parts compatibilizer.

[0042] The compatibilizer is prepared by the following steps: S1. By mass fraction, 5.46 parts of 1H,1H,2H-perfluoro-1-dodecene, 1.05 parts of diethanolamine, 0.38 parts of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, and 20 parts of N,N-dimethylformamide were mixed in a three-necked flask equipped with a reflux condenser and a magnetic stirrer. After turning on the magnetic stirrer, the mixture was reacted at 100°C for 3.5 h. After the reaction was completed, the reaction solution was cooled to room temperature and poured into deionized water. After extraction with dichloromethane, the solvent was removed by rotary evaporation to obtain intermediate 1. S2. By mass, 5.21 parts of intermediate 1, 0.78 parts of 1-chloropropane, and 15 parts of N,N-dimethylformamide were mixed in a three-necked flask equipped with a reflux condenser and a magnetic stirrer. After turning on the magnetic stirrer, the mixture was reacted at 85°C for 8 hours. After the reaction was completed, the reaction solution was cooled to room temperature and poured into petroleum ether to precipitate. After filtering to separate the solid, the mixture was washed with anhydrous ethanol and deionized water and dried to obtain intermediate 2. S3. By mass, 4.67 parts of intermediate 2 and 17.5 parts of N,N-dimethylformamide were mixed in a three-necked flask equipped with a reflux condenser and a magnetic stirrer. After turning on the magnetic stirrer, the system temperature was raised to 50°C. Then, 0.78 parts of phosphorus pentoxide were added to the system in three batches, with each batch containing 0.26 parts and the interval between each batch being 30 min. After adding all the phosphorus pentoxide, the temperature was maintained at 50°C and the reaction was continued for 30 min. Then, 0.5 parts of deionized water were added to the system, and the system temperature was raised to 65°C. The reaction was continued at 65°C for 30 min. After the reaction was completed, the reaction solution was cooled to room temperature and poured into petroleum ether to precipitate. After filtering to separate the solid, it was washed with anhydrous ethanol and deionized water to obtain the compatibilizer.

[0043] The above raw materials are processed into a sealing material through the following steps: Step 1: According to the mass fraction, 14.3 parts of aluminum nitride filler were heat-treated at 300℃ for 1.5h, and then surface impurities were removed by acid washing. Then, the acid-washed aluminum nitride filler, 3.5 parts of compatibilizer and 87.5 parts of N,N-dimethylformamide were mixed and ultrasonically treated for 35min. After ultrasonic treatment, the solid was filtered out, washed with deionized water and dried to obtain modified aluminum nitride filler. Step 2: By weight, 67.5 parts of polytetrafluoroethylene resin and 15.2 parts of modified aluminum nitride filler are added to a high-speed mixer and mixed evenly. After standing and curing, a preform is obtained. The preform is then pressed under a pressure of 30 MPa for 4 minutes to obtain a green compact. Finally, the green compact is preheated at a temperature of 300℃ for 45 minutes. Then, the temperature is raised to 365℃ and fired at 365℃ for 2.5 hours. After cooling, the sealing material is obtained.

[0044] Experimental Example 1 The compatibilizer obtained in Example 1 was characterized by infrared spectroscopy. Infrared spectroscopy was performed on a Nicolet 6700 Fourier transform infrared spectrometer (Thermo Scientific, USA) after potassium bromide tableting. Figure 1 As shown, in the range of 3000–2800 cm -1 A methylene stretching vibration peak appears at 2500–2200 cm⁻¹, due to the formation of intramolecular hydrogen bonds. -1 The OH stretching vibration peak appears at 1350–1100 cm⁻¹. -1 Stretching vibration peaks of trifluoromethyl and difluoromethylene appear at 1050–950 cm⁻¹. -1 The presence of a POC stretching vibration peak at the point indicates that the reaction was successful and the compatibilizer was obtained.

[0045] Experiment Example 2 Creep tests, compressive strength tests, and wear resistance tests were conducted on the sealing materials obtained in Examples 1-3 and Comparative Examples 1-2, respectively. The test results are shown in Tables 1 and 2.

[0046] Creep resistance test: The sealing materials in Examples 1-3 and Comparative Examples 1-2 were tested in accordance with the national standard GB / T20671.5-2020 "Classification system and test methods for non-metallic gasket materials".

[0047] Compressive strength test: The sealing materials in Examples 1-3 and Comparative Examples 1-2 were tested in accordance with the national standard GB / T 1041-2018 "Determination of compressive properties of plastics".

[0048] Wear resistance test: The sealing materials in Examples 1-3 and Comparative Examples 1-2 were rubbed for 1 hour under a load of 30N, a rotation speed of 1000rpm, and dry conditions. The wear volume of each component sealing material after friction was recorded.

[0049] Table 1

[0050] Table 2

[0051] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A sealing material, characterized in that, The raw materials contain the following parts by weight: 60-75 parts of polytetrafluoroethylene resin, 10-20 parts of perfluorosulfonic acid resin, 15-20 parts of filler, and 3-4 parts of compatibilizer. The compatibilizer is prepared by the following steps: S1. Intermediate 1 is obtained by Michael addition reaction of fluoroolefins with diethanolamine; S2. Intermediate 2 is obtained by reacting intermediate 1 with a haloalkane as a quaternary ammonium salt. S3. A compatibilizer is obtained by phosphorylation of intermediate 2 with phosphorus pentoxide.

2. The sealing material according to claim 1, characterized in that, The packing material is aluminum-based.

3. The sealing material according to claim 1, characterized in that, The fluoroolefin has the following structure: CF3 (CF2) n CH=CH2, where n is a natural number greater than 6 and less than 12.

4. The sealing material according to claim 1, characterized in that, The haloalkane has the following structure: CH3(CH2) n X, where n is a natural number greater than 0 and less than 4, and X is one of Br or Cl.

5. A sealing material according to claim 1, characterized in that, The sealing material is made by the following steps: Step 1: After thermally activating the filler, remove surface impurities by acid washing. Then mix the acid-washed filler, compatibilizer, and organic solvent and ultrasonically treat it. After ultrasonic treatment, filter out the solid, wash it with deionized water, and dry it to obtain the modified filler. Step 2: Mix polytetrafluoroethylene resin, perfluorosulfonic acid resin and modified filler evenly and let stand to mature to obtain preform material. Then, mold the preform material to obtain green preform. Finally, sinter the green preform and cool it to obtain sealing material.

6. A sealing material according to claim 5, characterized in that, The organic solvent is one of N,N-dimethylformamide and N,N-dimethylacetamide.

7. A sealing material according to claim 5, characterized in that, The conditions for thermal activation are heat treatment at 250–350℃ for 1–2 hours and ultrasonic treatment for 25–45 minutes.

8. A sealing material according to claim 5, characterized in that, The compression molding conditions are to press for 3 to 5 minutes under a pressure of 25 to 35 MPa.

9. A sealing material according to claim 5, characterized in that, The sintering conditions are as follows: preheat at 280–320°C for 30–60 minutes, then raise the temperature to 355–375°C and fire at 355–375°C for 2–3 hours.

10. The sealing material according to any one of claims 1 to 9 is used in a decolorizing reactor for intermediate synthesis.

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