Nano-particle reinforced polytetrafluoroethylene anti-corrosion pipe and preparation method thereof

Abstract

The invention relates to the field of anti-corrosion pipelines, in particular to a nano-particle reinforced polytetrafluoroethylene anti-corrosion pipe and a preparation method thereof, and is used for solving the problems that an existing polytetrafluoroethylene anti-corrosion pipe is poor in mechanical property, and the anti-corrosion effect needs to be improved. According to the anti-corrosion pipe, the polytetrafluoroethylene resin serves as a main raw material, the polytetrafluoroethylene resin has excellent chemical corrosion resistance and can resist erosion of various corrosive media, long-term stable use of the anti-corrosion pipe in a severe environment is guaranteed, then the composite modified carbon fibers and the polydopamine modified boron nitride are added to serve as reinforcing phases, and the corrosion resistance of the anti-corrosion pipe is improved. According to the present invention, the mechanical property of the anti-corrosion pipe can be substantially improved, the anti-corrosion pipe can bear the high pressure and the high friction force, the application range is expanded, the high requirement of the modernized industry on the corrosive medium transmission in the severe environment can be met, and the preparation method has advantages of simple process, easy operation, easy industrial production realization, and high application value.

Description

Technical Field

[0001] The present invention relates to the field of anti-corrosion pipelines, and in particular to a nano-particle-reinforced polytetrafluoroethylene anti-corrosion pipe and a preparation method thereof. Background Art

[0002] In the chemical, marine, and power industries, piping systems often face harsh corrosive environments, and the corrosion resistance of traditional metal pipes is no longer sufficient. Polytetrafluoroethylene (PTFE) is an ideal corrosion-resistant piping material due to its excellent chemical stability, low friction coefficient, and high-temperature resistance. However, pure PTFE suffers from low mechanical strength and poor wear resistance, limiting its application in high-pressure, high-wear environments. Furthermore, its corrosion resistance is compromised in extreme environments or during long-term use, making it difficult to meet the stringent requirements of modern industry for the transmission of corrosive media in harsh environments.

[0003] Therefore, it is of great practical significance to develop a polytetrafluoroethylene anti-corrosion pipe with excellent mechanical properties, thermal conductivity and corrosion resistance and a preparation method thereof. Summary of the Invention

[0004] In order to overcome the above technical problems, the purpose of the present invention is to provide a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe and a preparation method thereof, which solves the problem that the mechanical properties of existing polytetrafluoroethylene anti-corrosion pipes are poor and the anti-corrosion effect needs to be improved.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe comprises the following components in parts by weight:

[0007] 80-85 parts of polytetrafluoroethylene resin, 0.5-5 parts of composite modified carbon fiber and 2-8 parts of polydopamine modified boron nitride;

[0008] Wherein, the composite modified carbon fiber is prepared by the following steps:

[0009] The carbon fiber is placed in a tubular furnace, and then calcined at a constant temperature of 500-520°C for 1-2h, then cooled with the furnace, and then added to a three-necked flask equipped with a stirrer and a thermometer, and then anhydrous ethanol is added and ultrasonically treated at an ultrasonic frequency of 30-40kHz for 20-30min, and then adjusted to pH 8-9 with an ammonia solution, and then stirred for 10-20min at a temperature of 25-30°C and a stirring rate of 200-300r / min, and then a polysiloxane coupling agent is added and the stirring reaction is continued for 3-4h under the condition of heating to 70-75°C, and then nano-silica is added and the stirring reaction is continued for 2-3h. After the reaction, the reaction product is cooled to room temperature and then centrifuged. The precipitate is washed with distilled water 3-5 times, and then placed in a vacuum drying oven and dried at a temperature of 60-65°C for 3-5h to obtain a composite modified carbon fiber.

[0010] As a further solution of the present invention: the usage ratio of the carbon fiber, anhydrous ethanol, polysiloxane coupling agent and nano-silica is 5g:70-80mL:0.9-2.1g:1.1-2.5g.

[0011] As a further solution of the present invention: the carbon fiber is CCF300 carbon fiber with a diameter of 7.48 μm and a length of 25 mm; the mass fraction of the ammonia solution is 8-10%; and the average particle size of the nano-silicon dioxide is 30 nm.

[0012] As a further solution of the present invention: the polysiloxane coupling agent is prepared by the following steps:

[0013] Step a1: 1,3,5-tris(2-hydroxyethyl)cyanuric acid, mercaptopropionic acid, p-toluenesulfonic acid and anhydrous toluene are added to a three-necked flask equipped with a stirrer, a thermometer, an air guide tube and a reflux condenser, and nitrogen is introduced for protection. The mixture is stirred at a temperature of 20-25° C. and a stirring rate of 200-300 r / min for 20-30 minutes, and then the temperature is raised to reflux and the stirring reaction is continued for 5-6 hours. After the reaction is completed, the reaction product is cooled to room temperature, and then washed with sodium hydroxide solution and distilled water 3-5 times in sequence, and then dried with anhydrous magnesium sulfate, and then vacuum filtered. The filtrate is rotary evaporated to remove the solvent to obtain a polythiol intermediate;

[0014] Step a2: Add the polythiol intermediate, γ-methacryloxypropyltrimethoxysilane and anhydrous toluene to a three-necked flask equipped with a stirrer, a thermometer, a gas guide tube and a reflux condenser, introduce nitrogen protection, and stir the reaction at a temperature of 20-25°C and a stirring rate of 200-300 r / min for 10-20 minutes, then raise the temperature to reflux and continue stirring the reaction for 10-15 hours. After the reaction is completed, the reaction product is cooled to room temperature, and then the solvent is removed by rotary evaporation to obtain a polysiloxane coupling agent.

[0015] As a further embodiment of the present invention: the usage ratio of the 1,3,5-tris(2-hydroxyethyl)cyanuric acid, mercaptopropionic acid, p-toluenesulfonic acid and anhydrous toluene in step a1 is 10 mmol:30 mmol:0.05-0.15 g:70-80 mL.

[0016] As a further solution of the present invention: the mass fraction of the sodium hydroxide solution in step a1 is 8-10%.

[0017] As a further solution of the present invention: the usage ratio of the polythiol intermediate, γ-methacryloxypropyltrimethoxysilane and anhydrous toluene in step a2 is 10 mmol:30 mmol:70-80 mL.

[0018] As a further solution of the present invention: the polydopamine-modified boron nitride is prepared by the following steps:

[0019] Tris(hydroxymethyl)aminomethane and deionized water are added to a three-necked flask equipped with a stirrer and a thermometer, and the mixture is stirred and reacted for 20-30 minutes at a temperature of 25-30°C and a stirring rate of 200-300 r / min. The pH is then adjusted to 8.5 with a hydrochloric acid solution. Dopamine hydrochloride and hexagonal boron nitride are then added and the temperature is raised to 60-65°C and the stirring reaction is continued for 20-30 hours. After the reaction is completed, the reaction product is cooled to room temperature and then centrifuged. The precipitate is then washed with distilled water for 3-5 times and then placed in a vacuum drying oven and dried at a temperature of 60-65°C for 5-7 hours to obtain polydopamine-modified boron nitride.

[0020] As a further solution of the present invention: the usage ratio of tris(hydroxymethyl)aminomethane, deionized water, dopamine hydrochloride and hexagonal boron nitride is 0.484 g:100-120 mL:0.8 g:3 g.

[0021] As a further solution of the present invention: the molar concentration of the hydrochloric acid solution is 0.1 mol / L; and the average particle size of the hexagonal boron nitride is 50 nm.

[0022] As a further solution of the present invention: a method for preparing a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe comprises the following steps:

[0023] Step 1: Weigh 80-85 parts of polytetrafluoroethylene resin, 0.5-5 parts of composite modified carbon fiber, and 2-8 parts of polydopamine-modified boron nitride according to weight, and set aside; the polytetrafluoroethylene resin is JF-4TN PTFE suspended fine powder with an average particle size of 30 μm;

[0024] Step 2: adding polytetrafluoroethylene resin, composite modified carbon fiber and polydopamine modified boron nitride into a mixer, stirring and mixing at a temperature of 60-80° C. and a stirring rate of 400-500 r / min for 30-60 minutes to obtain a mixed material;

[0025] Step 3: Add the mixed material into the mold and press it at a pressure of 35-45 MPa for 15-25 minutes to obtain a tube blank;

[0026] Step 4: Place the tube blank in a box-type resistance furnace, heat it to 370-380°C at a heating rate of 5-9°C / min, and sinter it for 2-3 hours. Then cool it to room temperature in the furnace to obtain a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion tube.

[0027] Beneficial effects of the present invention:

[0028] The present invention discloses a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe and a preparation method thereof. The method comprises the following steps: stirring and mixing polytetrafluoroethylene resin, composite modified carbon fiber and polydopamine modified boron nitride to obtain a mixture; then pressing and molding the mixture to obtain a tube blank; and then sintering the tube blank to obtain the nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe. The anti-corrosion pipe uses polytetrafluoroethylene resin as a main raw material. The polytetrafluoroethylene resin itself has excellent chemical corrosion resistance and can resist the erosion of various strong acids, strong alkalis, organic solvents and other corrosive media, thereby ensuring the long-term stable use of the anti-corrosion pipe in harsh environments. Then, composite modified carbon fiber and polydopamine modified boron nitride are added thereto as reinforcing agents, which can significantly improve the mechanical properties of the anti-corrosion pipe, enable it to withstand higher pressure and friction, expand its application range, and meet the higher requirements of modern industry for the transmission of corrosive media in harsh environments. In addition, the preparation method has a simple process, is easy to operate, is easy to realize industrial production, and has high application value.

[0029] In the process of preparing polytetrafluoroethylene anti-corrosion pipe, a composite modified carbon fiber is first prepared. First, 1,3,5-tris(2-hydroxyethyl)cyanuric acid and mercaptopropionic acid are reacted. The hydroxyl group on 1,3,5-tris(2-hydroxyethyl)cyanuric acid reacts with the carboxyl group on mercaptopropionic acid to introduce a large number of mercapto groups to obtain a polythiol intermediate. Then, the polythiol intermediate and γ-methacryloxypropyltrimethoxysilane react. The mercapto group on the polythiol intermediate reacts with the alkenyl group on γ-methacryloxypropyltrimethoxysilane to undergo a click chemical reaction, thereby introducing a large number of siloxane groups to obtain a polysiloxane linker. Then, the polysiloxane linker is used to modify the carbon fiber after calcination and impurity removal, thereby significantly improving the dispersion performance of the carbon fiber. A large amount of silanol is grafted on the surface of carbon fiber, and nano-silica is coated on the surface of carbon fiber using a large amount of silanol to obtain composite modified carbon fiber; carbon fiber has the characteristics of high strength and high modulus. After being modified with a polysiloxane linker, the interface compatibility between carbon fiber and anti-corrosion pipe is significantly improved, so that the carbon fiber can be evenly dispersed in the anti-corrosion pipe, effectively enhancing the mechanical properties of the anti-corrosion pipe. After coating with nano-silica particles, the microscopic pores and grooves on the surface of carbon fiber are filled, making the surface of carbon fiber rougher, increasing the contact area with the anti-corrosion pipe, and further enhancing the interface bonding force. Moreover, nano-silica itself has certain strength and hardness, which plays a certain reinforcing role in the anti-corrosion pipe, thereby improving the overall mechanical properties of the anti-corrosion pipe.

[0030] In the process of preparing polytetrafluoroethylene anti-corrosion pipes, a polydopamine-modified boron nitride was also prepared. Hexagonal boron nitride has high hardness and wear resistance. Adding it as nanoparticles to the anti-corrosion pipe can significantly enhance the mechanical properties of the anti-corrosion pipe, and can synergize with composite modified carbon fibers to form a dense network structure, and reduce defects and pores inside the anti-corrosion pipe, improve the internal density of the anti-corrosion pipe, and can effectively block the penetration of corrosive media. Moreover, after polydopamine coating, the interfacial bonding force between hexagonal boron nitride and the anti-corrosion pipe can be improved, and polydopamine has excellent adhesion to further improve the internal density of the anti-corrosion pipe.

[0031] Combining the functions of the above parts, the entire anti-corrosion pipe forms an anti-corrosion protection system with high mechanical strength and good corrosion resistance through the joint cooperation of carbon fiber, polysiloxane coupling agent, nano-silica and polydopamine-modified boron nitride, ensuring its long-term use effect in extreme environments. DETAILED DESCRIPTION

[0032] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0033] Example 1:

[0034] This embodiment is a method for preparing a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe, comprising the following steps:

[0035] Step S1: 10 mmol 1,3,5-tris(2-hydroxyethyl)cyanuric acid, 30 mmol mercaptopropionic acid, 0.05 g p-toluenesulfonic acid and 70 mL anhydrous toluene were added to a three-necked flask equipped with a stirrer, a thermometer, a gas guide tube and a reflux condenser, and nitrogen was introduced for protection. The mixture was stirred at a temperature of 20° C. and a stirring rate of 200 r / min for 20 minutes, and then the temperature was raised to reflux and the stirring reaction was continued for 5 hours. After the reaction was completed, the reaction product was cooled to room temperature, and then washed with 8% sodium hydroxide solution and distilled water three times in sequence, and then dried with anhydrous magnesium sulfate. After vacuum filtration, the filtrate was rotary evaporated to remove the solvent to obtain a polythiol intermediate;

[0036] Step S2: 10 mmol of the polythiol intermediate, 30 mmol of γ-methacryloxypropyltrimethoxysilane, and 70 mL of anhydrous toluene were added to a three-necked flask equipped with a stirrer, a thermometer, a gas guide tube, and a reflux condenser. Nitrogen protection was introduced, and the mixture was stirred at a temperature of 20° C. and a stirring rate of 200 r / min for 10 minutes. The mixture was then heated to reflux and stirred for 10 hours. After the reaction was completed, the reaction product was cooled to room temperature, and then the solvent was removed by rotary evaporation to obtain a polysiloxane coupling agent.

[0037] Step S3: 5g of CCF300 carbon fiber with a diameter of 7.48μm and a length of 25mm is placed in a tube furnace, and then calcined at a constant temperature of 500℃ for 1h, then cooled with the furnace, and then added to a three-necked flask equipped with a stirrer and a thermometer, and then 70mL of anhydrous ethanol is added and ultrasonically treated for 20min at an ultrasonic frequency of 30kHz, and then adjusted to pH 8 with an 8% ammonia solution, and then stirred for 10min at a temperature of 25℃ and a stirring rate of 200r / min, and then 0.9g of polysiloxane coupling agent is added and the stirring reaction is continued for 3h under the condition of heating to 70℃, and then 1.1g of nano-silica with an average particle size of 30nm is added and the stirring reaction is continued for 2h. After the reaction, the reaction product is cooled to room temperature and then centrifuged. The precipitate is washed 3 times with distilled water, and then placed in a vacuum drying oven and dried at a temperature of 60℃ for 3h to obtain a composite modified carbon fiber;

[0038] Step S4: 0.484 g of tris(hydroxymethyl)aminomethane and 100 mL of deionized water were added to a three-necked flask equipped with a stirrer and a thermometer, and the mixture was stirred at 25° C. and a stirring rate of 200 r / min for 20 min. The pH was then adjusted to 8.5 with a hydrochloric acid solution having a molar concentration of 0.1 mol / L. 0.8 g of dopamine hydrochloride and 3 g of hexagonal boron nitride having an average particle size of 50 nm were then added and the mixture was heated to 60° C. and stirred for 20 h. After the reaction was completed, the reaction product was cooled to room temperature and then centrifuged. The precipitate was washed three times with distilled water and then placed in a vacuum drying oven and dried at 60° C. for 5 h to obtain polydopamine-modified boron nitride.

[0039] Step S5: Weigh 80 parts of polytetrafluoroethylene resin, 0.5 parts of composite modified carbon fiber, and 2 parts of polydopamine-modified boron nitride according to weight and set aside; the polytetrafluoroethylene resin is JF-4TN PTFE suspended fine powder with an average particle size of 30 μm;

[0040] Step S6: adding polytetrafluoroethylene resin, composite modified carbon fiber and polydopamine modified boron nitride into a mixer, stirring and mixing at a temperature of 60° C. and a stirring rate of 400 r / min for 30 minutes to obtain a mixed material;

[0041] Step S7: adding the mixed material into a mold and pressing at a pressure of 35 MPa for 15 minutes to obtain a tube blank;

[0042] Step S8: placing the tube blank in a box-type resistance furnace, heating the temperature to 370°C at a heating rate of 5°C / min, and sintering for 2 hours, and then cooling the tube blank to room temperature to obtain a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion tube.

[0043] Example 2:

[0044] This embodiment is a method for preparing a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe, comprising the following steps:

[0045] Step S1: 10 mmol 1,3,5-tris(2-hydroxyethyl)cyanuric acid, 30 mmol mercaptopropionic acid, 0.1 g p-toluenesulfonic acid and 75 mL anhydrous toluene were added to a three-necked flask equipped with a stirrer, a thermometer, a gas guide tube and a reflux condenser, and nitrogen was introduced for protection. The mixture was stirred at a temperature of 22° C. and a stirring rate of 250 r / min for 25 minutes, and then the temperature was raised to reflux and the stirring reaction was continued for 5.5 hours. After the reaction was completed, the reaction product was cooled to room temperature, and then washed with 9% sodium hydroxide solution and distilled water four times in sequence, and then dried with anhydrous magnesium sulfate. After vacuum filtration, the filtrate was rotary evaporated to remove the solvent to obtain a polythiol intermediate;

[0046] Step S2: 10 mmol of the polythiol intermediate, 30 mmol of γ-methacryloxypropyltrimethoxysilane, and 75 mL of anhydrous toluene were added to a three-necked flask equipped with a stirrer, a thermometer, a gas guide tube, and a reflux condenser. Nitrogen protection was introduced, and the mixture was stirred at a temperature of 22° C. and a stirring rate of 250 r / min for 15 minutes. The mixture was then heated to reflux and stirred for 12 hours. After the reaction was completed, the reaction product was cooled to room temperature, and then the solvent was removed by rotary evaporation to obtain a polysiloxane coupling agent;

[0047] Step S3: 5 g of CCF300 carbon fiber with a diameter of 7.48 μm and a length of 25 mm was placed in a tube furnace, and then calcined at a constant temperature of 510 ° C for 1.5 h, and then cooled with the furnace, and then added to a three-necked flask equipped with a stirrer and a thermometer, and then added 75 mL of anhydrous ethanol and ultrasonically treated at an ultrasonic frequency of 35 kHz for 25 min, and then adjusted to pH 8.5 with a 9% ammonia solution, and then stirred at a temperature of 28 ° C. The reaction was stirred at a rate of 250 r / min for 15 minutes, and then 1.5 g of a polysiloxane coupling agent was added and the temperature was raised to 72 ° C. and the stirring reaction was continued for 3.5 hours. Then, 1.8 g of nano-silica with an average particle size of 30 nm was added and the stirring reaction was continued for 2.5 hours. After the reaction was completed, the reaction product was cooled to room temperature and then centrifuged. The precipitate was washed with distilled water 4 times and then placed in a vacuum drying oven and dried at a temperature of 62 ° C for 4 hours to obtain a composite modified carbon fiber.

[0048] Step S4: 0.484 g of tris(hydroxymethyl)aminomethane and 110 mL of deionized water were added to a three-necked flask equipped with a stirrer and a thermometer, and the mixture was stirred at a temperature of 28 ° C and a stirring rate of 250 r / min for 25 minutes. The pH was then adjusted to 8.5 with a hydrochloric acid solution having a molar concentration of 0.1 mol / L. 0.8 g of dopamine hydrochloride and 3 g of hexagonal boron nitride having an average particle size of 50 nm were then added and the mixture was heated to 62 ° C and stirred for 25 hours. After the reaction was completed, the reaction product was cooled to room temperature and then centrifuged. The precipitate was washed with distilled water 4 times and then placed in a vacuum drying oven and dried at 62 ° C for 6 hours to obtain polydopamine-modified boron nitride;

[0049] Step S5: Weigh 82 parts of polytetrafluoroethylene resin, 2.5 parts of composite modified carbon fibers, and 5 parts of polydopamine-modified boron nitride according to weight and set aside; the polytetrafluoroethylene resin is a JF-4TN PTFE suspended fine powder with an average particle size of 30 μm;

[0050] Step S6: adding polytetrafluoroethylene resin, composite modified carbon fiber and polydopamine modified boron nitride into a mixer, stirring and mixing at a temperature of 70° C. and a stirring rate of 450 r / min for 45 minutes to obtain a mixed material;

[0051] Step S7: adding the mixed material into a mold and pressing at a pressure of 40 MPa for 20 minutes to obtain a tube blank;

[0052] Step S8: placing the tube blank in a box-type resistance furnace, heating the temperature to 375°C at a heating rate of 7°C / min, and sintering for 2.5 hours, and then cooling the tube blank to room temperature to obtain a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion tube.

[0053] Example 3:

[0054] This embodiment is a method for preparing a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe, comprising the following steps:

[0055] Step S1: 10 mmol 1,3,5-tris(2-hydroxyethyl)cyanuric acid, 30 mmol mercaptopropionic acid, 0.15 g p-toluenesulfonic acid and 80 mL anhydrous toluene were added to a three-necked flask equipped with a stirrer, a thermometer, a gas guide tube and a reflux condenser, and nitrogen was introduced for protection. The mixture was stirred at a temperature of 25° C. and a stirring rate of 300 r / min for 30 minutes, and then the temperature was raised to reflux and the stirring reaction was continued for 6 hours. After the reaction was completed, the reaction product was cooled to room temperature, and then washed with 10% sodium hydroxide solution and distilled water 5 times in sequence, and then dried with anhydrous magnesium sulfate. After vacuum filtration, the filtrate was rotary evaporated to remove the solvent to obtain a polythiol intermediate;

[0056] Step S2: 10 mmol of the polythiol intermediate, 30 mmol of γ-methacryloxypropyltrimethoxysilane, and 80 mL of anhydrous toluene were added to a three-necked flask equipped with a stirrer, a thermometer, a gas guide tube, and a reflux condenser. Nitrogen protection was introduced, and the mixture was stirred at a temperature of 25° C. and a stirring rate of 300 r / min for 20 minutes. The temperature was then raised to reflux and the stirring reaction was continued for 15 hours. After the reaction was completed, the reaction product was cooled to room temperature, and then the solvent was removed by rotary evaporation to obtain a polysiloxane coupling agent;

[0057] Step S3: 5g of CCF300 carbon fiber with a diameter of 7.48μm and a length of 25mm is placed in a tube furnace, and then calcined at a constant temperature of 520℃ for 2h, then cooled with the furnace, and then added to a three-necked flask equipped with a stirrer and a thermometer, and then 80mL of anhydrous ethanol is added and ultrasonically treated for 30min at an ultrasonic frequency of 40kHz, and then adjusted to pH 9 with a 10% ammonia solution, and then stirred for 20min at a temperature of 30℃ and a stirring rate of 300r / min, and then 2.1g of polysiloxane coupling agent is added and the stirring reaction is continued for 4h under the condition of heating to 75℃, and then 2.5g of nano-silica with an average particle size of 30nm is added and the stirring reaction is continued for 3h. After the reaction, the reaction product is cooled to room temperature and then centrifuged. The precipitate is washed with distilled water 5 times, and then placed in a vacuum drying oven and dried at a temperature of 65℃ for 5h to obtain a composite modified carbon fiber;

[0058] Step S4: 0.484 g of tris(hydroxymethyl)aminomethane and 120 mL of deionized water were added to a three-necked flask equipped with a stirrer and a thermometer, and the mixture was stirred at 30° C. and a stirring rate of 300 r / min for 30 min. The pH was then adjusted to 8.5 with a hydrochloric acid solution having a molar concentration of 0.1 mol / L. 0.8 g of dopamine hydrochloride and 3 g of hexagonal boron nitride having an average particle size of 50 nm were then added and the mixture was heated to 65° C. and stirred for 30 h. After the reaction was completed, the reaction product was cooled to room temperature and then centrifuged. The precipitate was washed with distilled water 5 times and then placed in a vacuum drying oven and dried at 65° C. for 7 h to obtain polydopamine-modified boron nitride.

[0059] Step S5: Weigh 85 parts of polytetrafluoroethylene resin, 5 parts of composite modified carbon fiber, and 8 parts of polydopamine-modified boron nitride according to weight and set aside; the polytetrafluoroethylene resin is JF-4TN PTFE suspended fine powder with an average particle size of 30 μm;

[0060] Step S6: adding polytetrafluoroethylene resin, composite modified carbon fiber and polydopamine modified boron nitride into a mixer, stirring and mixing at a temperature of 80° C. and a stirring rate of 500 r / min for 60 minutes to obtain a mixed material;

[0061] Step S7: adding the mixed material into a mold and pressing at a pressure of 45 MPa for 25 minutes to obtain a tube blank;

[0062] Step S8: placing the tube blank in a box-type resistance furnace, heating the temperature to 380° C. at a heating rate of 9° C. / min, and sintering the tube for 3 hours. Then, cooling the tube blank to room temperature in the furnace to obtain a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion tube.

[0063] Comparative Example 1:

[0064] This comparative example is a method for preparing a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe, comprising the following steps:

[0065] Step S1: adding polytetrafluoroethylene resin into a mold and pressing at a pressure of 45 MPa for 25 minutes to obtain a tube blank; the polytetrafluoroethylene resin is JF-4TN PTFE suspended fine powder with an average particle size of 30 μm;

[0066] Step S2: placing the tube blank in a box-type resistance furnace, heating the temperature to 380°C at a heating rate of 9°C / min, and sintering for 3 hours, and then cooling the tube blank to room temperature to obtain a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion tube.

[0067] Comparative Example 2:

[0068] This comparative example is a method for preparing a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe, comprising the following steps:

[0069] Step S1: 10 mmol 1,3,5-tris(2-hydroxyethyl)cyanuric acid, 30 mmol mercaptopropionic acid, 0.15 g p-toluenesulfonic acid and 80 mL anhydrous toluene were added to a three-necked flask equipped with a stirrer, a thermometer, a gas guide tube and a reflux condenser, and nitrogen was introduced for protection. The mixture was stirred at a temperature of 25° C. and a stirring rate of 300 r / min for 30 minutes, and then the temperature was raised to reflux and the stirring reaction was continued for 6 hours. After the reaction was completed, the reaction product was cooled to room temperature, and then washed with 10% sodium hydroxide solution and distilled water 5 times in sequence, and then dried with anhydrous magnesium sulfate. After vacuum filtration, the filtrate was rotary evaporated to remove the solvent to obtain a polythiol intermediate;

[0070] Step S2: 10 mmol of the polythiol intermediate, 30 mmol of γ-methacryloxypropyltrimethoxysilane, and 80 mL of anhydrous toluene were added to a three-necked flask equipped with a stirrer, a thermometer, a gas guide tube, and a reflux condenser. Nitrogen protection was introduced, and the mixture was stirred at a temperature of 25° C. and a stirring rate of 300 r / min for 20 minutes. The temperature was then raised to reflux and the stirring reaction was continued for 15 hours. After the reaction was completed, the reaction product was cooled to room temperature, and then the solvent was removed by rotary evaporation to obtain a polysiloxane coupling agent;

[0071] Step S3: 5g of CCF300 carbon fiber with a diameter of 7.48μm and a length of 25mm is placed in a tube furnace, and then calcined at a constant temperature of 520℃ for 2h, then cooled with the furnace, and then added to a three-necked flask equipped with a stirrer and a thermometer, and then 80mL of anhydrous ethanol is added and ultrasonically treated for 30min at an ultrasonic frequency of 40kHz, and then adjusted to pH 9 with a 10% ammonia solution, and then stirred for 20min at a temperature of 30℃ and a stirring rate of 300r / min, and then 2.1g of polysiloxane coupling agent is added and the stirring reaction is continued for 4h under the condition of heating to 75℃, and then 2.5g of nano-silica with an average particle size of 30nm is added and the stirring reaction is continued for 3h. After the reaction, the reaction product is cooled to room temperature and then centrifuged. The precipitate is washed with distilled water 5 times, and then placed in a vacuum drying oven and dried at a temperature of 65℃ for 5h to obtain a composite modified carbon fiber;

[0072] Step S4: Weigh 85 parts of polytetrafluoroethylene resin and 5 parts of composite modified carbon fiber according to weight and set aside; the polytetrafluoroethylene resin is JF-4TN PTFE suspended fine powder with an average particle size of 30 μm;

[0073] Step S5: adding polytetrafluoroethylene resin and composite modified carbon fiber into a mixer, stirring and mixing at a temperature of 80° C. and a stirring rate of 500 r / min for 60 minutes to obtain a mixed material;

[0074] Step S6: adding the mixed material into a mold and pressing at a pressure of 45 MPa for 25 minutes to obtain a tube blank;

[0075] Step S7: placing the tube blank in a box-type resistance furnace, heating the temperature to 380° C. at a heating rate of 9° C. / min, and sintering the tube for 3 hours. Then, cooling the tube blank to room temperature in the furnace to obtain a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion tube.

[0076] Comparative Example 3:

[0077] This comparative example is a method for preparing a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe, comprising the following steps:

[0078] Step S1: 0.484 g of tris(hydroxymethyl)aminomethane and 120 mL of deionized water were added to a three-necked flask equipped with a stirrer and a thermometer, and the mixture was stirred at a temperature of 30° C. and a stirring rate of 300 r / min for 30 min. The pH was then adjusted to 8.5 with a hydrochloric acid solution having a molar concentration of 0.1 mol / L. 0.8 g of dopamine hydrochloride and 3 g of hexagonal boron nitride having an average particle size of 50 nm were then added and the mixture was heated to 65° C. and stirred for 30 h. After the reaction was completed, the reaction product was cooled to room temperature and then centrifuged. The precipitate was washed with distilled water 5 times, and then placed in a vacuum drying oven and dried at 65° C. for 7 h to obtain polydopamine-modified boron nitride;

[0079] Step S2: Weigh 85 parts of polytetrafluoroethylene resin and 8 parts of polydopamine-modified boron nitride according to weight and set aside; the polytetrafluoroethylene resin is JF-4TN PTFE suspended fine powder with an average particle size of 30 μm;

[0080] Step S3: adding polytetrafluoroethylene resin and polydopamine-modified boron nitride into a mixer, stirring and mixing at a temperature of 80° C. and a stirring rate of 500 r / min for 60 minutes to obtain a mixed material;

[0081] Step S4: adding the mixed material into a mold and pressing at a pressure of 45 MPa for 25 minutes to obtain a tube blank;

[0082] Step S5: placing the tube blank in a box-type resistance furnace, heating the temperature to 380° C. at a heating rate of 9° C. / min, and sintering the tube for 3 hours. Then, cooling the tube blank to room temperature in the furnace to obtain a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion tube.

[0083] Comparative Example 4:

[0084] This comparative example is a method for preparing a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe, comprising the following steps:

[0085] Step S1: 85 parts of polytetrafluoroethylene resin, 5 parts of CCF300 carbon fiber with a diameter of 7.48 μm and a length of 25 mm, and 8 parts of hexagonal boron nitride with an average particle size of 50 nm are weighed and set aside; the polytetrafluoroethylene resin is a JF-4TN PTFE suspended fine powder with an average particle size of 30 μm;

[0086] Step S2: adding polytetrafluoroethylene resin, carbon fiber and hexagonal boron nitride into a mixer, stirring and mixing at a temperature of 80° C. and a stirring rate of 500 r / min for 60 minutes to obtain a mixed material;

[0087] Step S3: adding the mixed material into a mold and pressing at a pressure of 45 MPa for 25 minutes to obtain a tube blank;

[0088] Step S4: placing the tube blank in a box-type resistance furnace, heating the temperature to 380°C at a heating rate of 9°C / min, and sintering for 3 hours, and then cooling the tube blank to room temperature to obtain a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion tube.

[0089] According to GBT 1039-1992, the initial compressive strength and initial tensile strength of Examples 1-3 and Comparative Examples 1-4 were tested, as were the post-acid compressive strength and post-acid tensile strength after immersion in a 98% by mass sulfuric acid solution for 48 hours, and the post-alkali compressive strength and post-alkali tensile strength after immersion in a 40% by mass sodium hydroxide solution for 48 hours. The test results are shown in the following table:

[0090]

[0091] Referring to the data in the above table, based on the comparison between Examples 1-3 and Comparative Examples 1-4, it can be seen that the nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe of the present application has excellent mechanical properties, and can maintain excellent mechanical properties after acid treatment and alkali treatment, indicating that it has excellent chemical corrosion resistance.

[0092] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0093] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined in this application, they should all fall within the scope of protection of the present invention.

Claims

1. A nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe, characterized in that: It comprises the following components in parts by weight: 80-85 parts of polytetrafluoroethylene resin, 0.5-5 parts of composite modified carbon fiber and 2-8 parts of polydopamine modified boron nitride; Wherein, the composite modified carbon fiber is prepared by the following steps: The carbon fiber is calcined, then cooled and ultrasonically treated in anhydrous ethanol, and then the pH is adjusted with an ammonia solution. Then, a polysiloxane coupling agent is added for stirring reaction, and then nano-silica is added and the stirring reaction is continued. After the reaction is completed, the reaction product is cooled and centrifuged. Then, the precipitate is washed and dried to obtain a composite modified carbon fiber.

2. The nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe according to claim 1, characterized in that: The usage ratio of the carbon fiber, anhydrous ethanol, polysiloxane coupling agent and nano-silica is 5g:70-80mL: 0.9-2.1g:1.1-2.5g.

3. The nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe according to claim 1, characterized in that: The mass fraction of the ammonia solution is 8-10%.

4. The nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe according to claim 1, characterized in that: The polysiloxane coupling agent is prepared by the following steps: Step a1: stirring 1,3,5-tris(2-hydroxyethyl)cyanuric acid, mercaptopropionic acid, p-toluenesulfonic acid, and anhydrous toluene to react. After the reaction, the reaction product is cooled, washed, dried, and then vacuum filtered. The filtrate is rotary evaporated to obtain a polythiol intermediate; Step a2: stirring the polythiol intermediate, γ-methacryloxypropyltrimethoxysilane and anhydrous toluene to react, cooling the reaction product after the reaction is completed, and then rotary evaporating to obtain a polysiloxane coupling agent.

5. The nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe according to claim 4, characterized in that: The usage ratio of the 1,3,5-tris(2-hydroxyethyl)cyanuric acid, mercaptopropionic acid, p-toluenesulfonic acid and anhydrous toluene in step a1 is 10 mmol:30 mmol:0.05-0.15 g:70-80 mL.

6. The nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe according to claim 4, characterized in that: The usage ratio of the polythiol intermediate, γ-methacryloxypropyltrimethoxysilane and anhydrous toluene in step a2 is 10 mmol:30 mmol:70-80 mL.

7. The nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe according to claim 1, characterized in that: The polydopamine-modified boron nitride is prepared by the following steps: Tris(hydroxymethyl)aminomethane) and deionized water are stirred for reaction, and then the pH is adjusted with a hydrochloric acid solution. Dopamine hydrochloride and hexagonal boron nitride are then added and the stirring reaction is continued. After the reaction is completed, the reaction product is cooled and then centrifuged. The precipitate is then washed and dried to obtain polydopamine-modified boron nitride.

8. The nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe according to claim 7, characterized in that: The usage ratio of tris(hydroxymethyl)aminomethane, deionized water, dopamine hydrochloride and hexagonal boron nitride is 0.484 g:100-120 mL:0.8 g:3 g.

9. The nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe according to claim 7, characterized in that: The molar concentration of the hydrochloric acid solution is 0.1 mol / L.

10. A method for preparing a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion pipe, characterized in that: The following steps are involved: Step 1: Weigh 80-85 parts of polytetrafluoroethylene resin, 0.5-5 parts of composite modified carbon fiber, and 2-8 parts of polydopamine-modified boron nitride according to weight, and set aside; Step 2: adding polytetrafluoroethylene resin, composite modified carbon fiber and polydopamine modified boron nitride into a mixer, stirring and mixing at a temperature of 60-80° C. and a stirring rate of 400-500 r / min for 30-60 minutes to obtain a mixed material; Step 3: Add the mixed material into the mold and press it at a pressure of 35-45 MPa for 15-25 minutes to obtain a tube blank; Step 4: Place the tube blank in a box-type resistance furnace, heat it to 370-380°C at a heating rate of 5-9°C / min, and sinter it for 2-3 hours. Then cool it to room temperature in the furnace to obtain a nanoparticle-reinforced polytetrafluoroethylene anti-corrosion tube.

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