A method and system for the stepwise preparation of polyether ether ketone resins

Abstract

The application discloses a method and system for preparing polyether ether ketone (PEEK) resin by a step-by-step method. The method comprises negative pressure salt dehydration, positive pressure monomer addition and polymerization. In the negative pressure stage (‑0.06~‑0.09 MPa, 120~160℃), water is removed efficiently; in the positive pressure stage (0.05~0.14 MPa), 4,4'-difluorobenzophenone is added and polymerized at 280~320℃. The system is equipped with double condensation reaction towers and an intelligent control system, realizing alternating dehydration and continuous production. The method does not need to add water-carrying agents, effectively inhibits monomer volatilization and hydrolysis, and can stably prepare high-performance PEEK resin with high molecular weight (30,000~50,000 g / mol) and narrow distribution (PDI≤2.0).

Description

Technical Field

[0001] This invention relates to the field of polymer material synthesis technology, specifically to a method and system for preparing polyether ether ketone (PEEK) resin by a distribution method. Background Technology

[0002] Polyetheretherketone (PEEK) is a high-performance thermoplastic engineering plastic with excellent heat resistance, mechanical strength, chemical stability and flame retardancy. It is widely used in aerospace, medical devices, electronics and information technology and automotive industries.

[0003] The conventional synthetic route for PEEK involves nucleophilic substitution polycondensation of 4,4'-difluorobenzophenone (DFD) and hydroquinone (HQ) as monomers in the presence of alkaline catalysts such as potassium carbonate in inert high-boiling solvents such as diphenyl sulfone. Traditional processes often employ a one-step method, where all raw materials (DFD, HQ, alkali, and solvent) are added to the reactor at once and reacted at high temperatures (usually exceeding the boiling point of DFD). This process has the following main drawbacks: Significant DFD evaporation loss: DFD has a low boiling point and is highly volatile at reaction temperatures. The DFD vapor produced during evaporation is expelled from the system along with the moisture generated during the reaction and protective gases (such as inert gases), causing the actual concentration of DFD in the reaction system to continuously decrease and disrupting the strict molar ratio with hydroquinone. This directly leads to difficulty in increasing the molecular weight of the final polymer, a broadening of the molecular weight distribution (PDI), and unstable product quality.

[0004] DFD hydrolysis side reaction: In the initial stage of the reaction, the system is an alkaline aqueous environment (from the water generated by the salt formation of alkali and hydroquinone). At high temperatures, the fluorine atoms of DFD are prone to hydrolysis, generating inactive hydroxyl byproducts. This not only consumes expensive DFD monomers but also disrupts the reaction ratio and may introduce end-group defects, affecting product purity and performance.

[0005] Low reaction efficiency: Polycondensation is a reversible reaction, requiring timely removal of the byproduct water to drive the reaction forward. In traditional processes, water mixes with the high-viscosity melt, making removal difficult and resulting in long reaction times and high energy consumption. To promote water removal, existing technologies often use azeotropic dehydration agents such as toluene and xylene. However, this method introduces additional organic solvents, posing a risk of solvent residue contamination of the product, increasing the complexity and cost of post-processing, and failing to solve the fundamental problem of DFD volatilization.

[0006] Therefore, developing a method for preparing high molecular weight narrow distribution PEEK resin without the need for external dehydrating agents, which can efficiently dehydrate and effectively suppress DFD volatilization and hydrolysis, is simple in process and can stably prepare the resin, has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] This invention aims to overcome the shortcomings of existing technologies and provide a stepwise method for preparing polyetheretherketone (PEEK) resin. This method employs an innovative process combining "negative pressure salt formation and dehydration" with "positive pressure protected polymerization," achieving rapid and efficient removal of moisture in the initial stage of the reaction without the need for additional dehydrating agents. Furthermore, it effectively inhibits the volatilization and hydrolysis of DFD monomers during the polymerization stage, thereby ensuring stable monomer ratios and ultimately obtaining high molecular weight, narrow distribution, and high-performance PEEK resin.

[0008] The technical solution of the present invention is as follows: In a first aspect, a method for preparing polyetheretherketone resin by a stepwise process includes the following steps: S1 negative pressure salt formation and dehydration stage: Under the protection of inert gas, hydroquinone and inorganic base are added to an inert aprotic solvent. After the temperature is raised to 120~160℃ for salt formation reaction for 1-3 hours, the system is evacuated to -0.01~-0.09MPa, and the generated water is removed through a condensation system until the removed water reaches more than 99% of the theoretical amount. S2 monomer addition and positive pressure protection stage: After the salt formation reaction is completed, inert gas is introduced into the system to restore the pressure to normal, the system temperature is reduced to 60~100℃, 4,4'-difluorobenzophenone is added, and then inert gas is introduced to raise the system pressure to 0.05~0.14 MPa; S3 Gradient heating polymerization stage: The system is heated to 280~320℃ at a rate of 5~10℃ / min, and the reaction is maintained under the positive pressure environment for 5~8 hours; S4 Post-processing stage: After the reaction is completed, the product is cooled, crushed, washed and dried to obtain polyether ether ketone resin.

[0009] Furthermore, the inorganic base is potassium carbonate, the molar ratio of the inorganic base to the hydroquinone is 1.05:1 to 1.15:1, and the molar ratio of 4,4'-difluorobenzophenone to hydroquinone is 1:1 to 1.02:1.

[0010] Furthermore, the inert aprotic solvent is diphenyl sulfone, and its amount is 150-300% of the total mass of the hydroquinone and the 4,4'-difluorobenzophenone.

[0011] Furthermore, in step S1, the negative pressure is -0.07 ~ -0.08 MPa.

[0012] Furthermore, in step S2, the system pressure is increased to 0.1~0.14 MPa.

[0013] In a second aspect, a polyetheretherketone resin preparation system for carrying out the stepwise preparation method of the polyetheretherketone resin includes: The reaction vessel unit includes a reaction vessel, a first condensation reaction tower, and a second condensation reaction tower. The first condensation reaction tower and the second condensation reaction tower are selectively connected to the top gas phase outlet of the reaction vessel through a first connecting valve and a second connecting valve, respectively. The vacuum unit includes a main vacuum pipeline, a first vacuum branch, and a second vacuum branch. The main vacuum pipeline is connected to an external vacuum source, and the first and second vacuum branches respectively connect the main vacuum pipeline to the first vacuum port of the first condensation reaction tower and the second vacuum port of the second condensation reaction tower. The gas replacement and pressure control unit includes an inert gas main pipeline, a main inert gas branch, a first inert gas branch, and a second inert gas branch. The main inert gas branch is connected to the reactor. The inert gas main pipeline is connected to the first replacement port of the first condensation reaction tower and the second replacement port of the second condensation reaction tower through the first and second inert gas branches, respectively. Heating devices are provided on both the first and second inert gas branches. The control system is a programmable logic controller or a distributed control system, which is connected to the first connecting valve, the second connecting valve, the first vacuum interface, the second vacuum interface, the first displacement interface, the second displacement interface, and the control valve signal on the main inert gas branch, respectively. The control system is configured to sequentially execute pressure and process control operations corresponding to steps S1 to S3 of claim 1 by controlling the opening and closing of the valves described above.

[0014] Furthermore, the control system is further configured to run an alternating vacuuming and displacement cycle program when performing the operation corresponding to step S1, with each cycle sequentially executing the following steps: (a) Open the first connecting valve and the first vacuum port, and close the second connecting valve, the first replacement port and the second replacement port, so that the reactor is connected to the vacuum unit through the first condensation reaction tower to perform vacuum dehydration for a first set time T1. (b) Open the second connecting valve and the second vacuum port, then close the first vacuum port and open the first replacement port; after the pressure stabilizes, close the first connecting valve; switch the reactor to be connected to the vacuum unit through the second condensation reaction tower (4), continue to evacuate and dehydrate, and continue for a third set time T3; at the same time, introduce heated inert gas into the first condensation reaction tower through the first replacement port for purging and replacement. (c) Open the first connecting valve and the first vacuum port, then close the second vacuum port and open the second displacement port; after the pressure stabilizes, close the second connecting valve; the system state returns to step (a) to enter the next cycle; at the same time, heated inert gas is introduced into the second condensation reaction tower through the second displacement port for purging and displacement.

[0015] Furthermore, the first set time T1 and the third set time T3 are both 7 minutes, and the waiting time after the pressure stabilizes in steps (b) and (c) is 3 minutes; and the main inert gas branch is equipped with a flow regulating valve, which is used to continuously introduce inert gas into the reactor at a flow rate of 1-5 liters / minute in steps S2 and S3.

[0016] Thirdly, a polyetheretherketone resin prepared by the stepwise method, wherein the polyetheretherketone resin has a number-average molecular weight of 30,000 to 50,000 g / mol, a molecular weight distribution of less than or equal to 2.0, and a glass transition temperature of greater than or equal to 143°C.

[0017] Fourthly, the application of the polyetheretherketone resin in high-performance engineering plastic products.

[0018] The advantages of this invention over the prior art are: 1. Highly efficient dehydration without the need for external dehydrating agents, simplifying the process and improving product purity: In the S1 stage, a negative pressure environment (-0.06 ~ -0.09 MPa) is used for salt formation and dehydration. The vacuum significantly lowers the boiling point of water, achieving highly efficient and rapid dehydration at a low temperature of 120~160℃, with a dehydration rate exceeding 99% of the theoretical yield. This method completely avoids the solvent residue risks associated with the introduction of azeotropic dehydrating agents such as toluene and xylene in traditional processes, simplifies the post-processing steps, reduces costs, and ensures higher purity in the final PEEK resin product.

[0019] 2. Effectively suppressing DFD monomer volatilization and hydrolysis, ensuring precise stoichiometry: Through a unique stepwise process design of "negative pressure dehydration-positive pressure polymerization," moisture in the reaction system is completely removed in stage S1, creating an anhydrous environment for 4,4'-difluorobenzophenone (DFD) added in stage S2, fundamentally eliminating the hydrolysis side reaction of DFD at high temperatures. In stages S2 and S3, by introducing inert gas into the system and maintaining a positive pressure (0.05~0.14 MPa), the boiling point of DFD is significantly increased, effectively suppressing its volatilization loss during the high-temperature polymerization stage (280~320℃). These two measures together ensure that the molar ratio of DFD to hydroquinone phenolate in the reaction system remains highly stable throughout the polymerization process.

[0020] 3. Significantly improves product molecular weight and quality, obtaining high-performance resin with narrow molecular weight distribution: Due to stable monomer ratios and reduced side reactions, the polymerization reaction proceeds more fully and uniformly. The method of this invention can stably prepare PEEK resin with a number-average molecular weight as high as 30,000~50,000 g / mol, and a narrow molecular weight distribution (PDI) (≤2.0) and a high glass transition temperature (≥143℃). This indicates that the product has higher chain regularity and superior mechanical and thermal properties.

[0021] 4. Optimized reaction efficiency and energy consumption: Negative pressure dehydration accelerates the water removal rate and shortens the salt formation stage time. The polymerization stage is carried out under positive pressure protection, resulting in a strong reaction driving force and more efficient degree of polymerization. The gradient heating strategy (5~10℃ / min) facilitates stable reaction and avoids localized overheating. In summary, this invention improves overall reaction efficiency and reduces energy consumption while ensuring product quality.

[0022] 5. A dedicated intelligent system enables precise process control and continuous production: The accompanying preparation system features a dual-condensation reaction tower and an intelligent control system. In stage S1, the control system automatically executes an alternating cycle of vacuuming and inert gas purging and replacement, ensuring continuous dehydration and preventing process interruptions due to blockage or efficiency reduction in a single condensation tower. This guarantees stable and efficient dehydration. The system accurately executes the pressure switching, temperature control, and process automation of the step-by-step method of this invention, significantly improving process reliability, repeatability, and feasibility for large-scale production.

[0023] In summary, this invention, through a combination of process innovation and equipment improvement, successfully solves key problems in traditional PEEK synthesis, such as the easy volatility and hydrolysis of DFD, difficulty in dehydration, and poor control of product molecular weight and distribution. It provides a high-quality PEEK resin preparation method that is efficient, stable, environmentally friendly, and easy to implement industrially. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of a polyetheretherketone resin preparation system for implementing the stepwise method of preparing polyetheretherketone resin according to the present invention.

[0026] Reference numerals: 1-First connecting valve, 2-Second connecting valve, 3-First condensation reaction tower, 4-Second condensation reaction tower, 5-Reaction vessel, 6-Main vacuum pipeline, 7-First vacuum branch, 8-Second vacuum branch, 9-First vacuum interface, 10-Second vacuum interface, 11-First inert gas branch, 12-Second inert gas branch, 13-First displacement interface, 14-Second displacement interface, 15-Main inert gas branch, 16-Main inert gas pipeline. Detailed Implementation

[0027] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limiting purposes, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details.

[0028] A stepwise method for preparing polyetheretherketone resin includes the following steps: S1 negative pressure salt formation and dehydration stage: Under the protection of inert gas, hydroquinone and inorganic base are added to an inert aprotic solvent. After the temperature is raised to 120~160℃ for salt formation reaction for 1-3 hours, the system is evacuated to -0.01~-0.09MPa, and the generated water is removed through a condensation system until the removed water reaches more than 99% of the theoretical amount. S2 monomer addition and positive pressure protection stage: After the salt formation reaction is completed, inert gas is introduced into the system to restore the pressure to normal, the system temperature is reduced to 60~100℃, 4,4'-difluorobenzophenone is added, and then inert gas is introduced to raise the system pressure to 0.05~0.14 MPa; S3 Gradient heating polymerization stage: The system is heated to 280~320℃ at a rate of 5~10℃ / min, and the reaction is maintained under the positive pressure environment for 5~8 hours; S4 Post-processing stage: After the reaction is completed, the product is cooled, crushed, washed and dried to obtain polyether ether ketone resin.

[0029] Furthermore, the inorganic base is potassium carbonate, the molar ratio of the inorganic base to the hydroquinone is 1.05:1 to 1.15:1, and the molar ratio of 4,4'-difluorobenzophenone to hydroquinone is 1:1 to 1.02:1.

[0030] Furthermore, the inert aprotic solvent is diphenyl sulfone, and its amount is 150-300% of the total mass of the hydroquinone and the 4,4'-difluorobenzophenone.

[0031] Furthermore, in step S1, the negative pressure is -0.07 ~ -0.08 MPa.

[0032] Furthermore, in step S2, the system pressure is increased to 0.1~0.14 MPa.

[0033] like Figure 1 As shown, a polyetheretherketone (PEEK) resin preparation system for carrying out the stepwise preparation method of the PEEK resin includes: The reaction vessel unit includes a reaction vessel 5, a first condensation reaction tower 3, and a second condensation reaction tower 4. The first condensation reaction tower 3 and the second condensation reaction tower 4 are selectively connected to the top gas phase outlet of the reaction vessel 5 through a first connecting valve 1 and a second connecting valve 2, respectively. The vacuum unit includes a main vacuum pipeline 6, a first vacuum branch 7, and a second vacuum branch 8. The main vacuum pipeline 6 is connected to an external vacuum source. The first vacuum branch 7 and the second vacuum branch 8 respectively connect the main vacuum pipeline 6 to the first vacuum interface 9 of the first condensation reaction tower 3 and the second vacuum interface 10 of the second condensation reaction tower 4. The gas replacement and pressure control unit includes an inert gas main pipeline 16, a main inert gas branch 15, a first inert gas branch 11, and a second inert gas branch 12. The main inert gas branch 15 is connected to the reactor 5. The inert gas main pipeline 16 is connected to the first replacement port 13 of the first condensation reaction tower 3 and the second replacement port 14 of the second condensation reaction tower 4 through the first inert gas branch 11 and the second inert gas branch 12, respectively. Heating devices (not shown in the figure) are provided on both the first inert gas branch 11 and the second inert gas branch 12. The control system is a programmable logic controller or a distributed control system, which is connected to the control valves on the first connecting valve 1, the second connecting valve 2, the first vacuum interface 9, the second vacuum interface 10, the first displacement interface 13, the second displacement interface 14, and the main inert gas branch 15, respectively. The control system is configured to sequentially execute pressure and process control operations corresponding to steps S1 to S3 of claim 1 by controlling the opening and closing of the valves described above.

[0034] Furthermore, the control system is further configured to run an alternating vacuuming and displacement cycle program when performing the operation corresponding to step S1, with each cycle sequentially executing the following steps: (a) Open the first connecting valve 1 and the first vacuum port 9, and close the second connecting valve 2, the first replacement port 13 and the second replacement port 14, so that the reactor 5 is connected to the vacuum unit through the first condensing reaction tower 3 to perform vacuum dehydration for a first set time T1. (b) Open the second connecting valve 2 and the second vacuum port 10, then close the first vacuum port 9 and open the first displacement port 13; after the pressure stabilizes, close the first connecting valve 1; switch the reactor 5 to be connected to the vacuum unit through the second condensation reaction tower 4, continue to evacuate and dehydrate, and continue for a third set time T3; at the same time, introduce heated inert gas into the first condensation reaction tower 3 through the first displacement port 13 for purging and displacement. (c) Open the first connecting valve 1 and the first vacuum port 9, then close the second vacuum port 10 and open the second displacement port 14; after the pressure stabilizes, close the second connecting valve 2; the system state returns to step (a) to enter the next cycle; at the same time, heated inert gas is introduced into the second condensation reaction tower 4 through the second displacement port 14 for purging and displacement.

[0035] Furthermore, the first set time T1 and the third set time T3 are both 7 minutes, and the waiting time after the pressure stabilizes in steps (b) and (c) is 3 minutes; and the main inert gas branch 15 is equipped with a flow regulating valve for continuously introducing inert gas into the reactor 5 at a flow rate of 1-5 liters / minute in steps S2 and S3.

[0036] A polyetheretherketone resin prepared by the stepwise method, wherein the polyetheretherketone resin has a number-average molecular weight of 30,000~50,000 g / mol, a molecular weight distribution of less than or equal to 2.0, and a glass transition temperature of greater than or equal to 143℃.

[0037] The application of the polyetheretherketone resin in high-performance engineering plastic products.

[0038] This invention employs a stepwise process of "negative pressure dehydration-positive pressure polymerization." Under negative pressure (-0.06~-0.09 MPa), the saline solution is efficiently removed, avoiding the use of traditional dehydrating agents and simplifying post-treatment. Polymerization is then carried out under positive pressure (0.05~0.14 MPa), effectively suppressing the volatilization and hydrolysis of 4,4'-difluorobenzophenone and ensuring stable monomer ratios. This method can stably prepare high-performance PEEK resins with a number-average molecular weight of 30,000~50,000 g / mol, a molecular weight distribution ≤2.0, and a glass transition temperature ≥143℃. It features high product purity, controllable molecular weight, and low process energy consumption.

[0039] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0040] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A stepwise method for preparing polyetheretherketone resin, characterized in that, Includes the following steps: S1 negative pressure salt formation and dehydration stage: Under the protection of inert gas, hydroquinone and inorganic base are added to an inert aprotic solvent. After the temperature is raised to 120~160℃ for salt formation reaction for 1-3 hours, the system is evacuated to -0.01--0.09MPa, and the generated water is removed through a condensation system until the removed water reaches more than 99% of the theoretical amount. S2 monomer addition and positive pressure protection stage: After the salt formation reaction is completed, inert gas is introduced into the system to restore the pressure to normal, the system temperature is reduced to 60~100℃, 4,4'-difluorobenzophenone is added, and then inert gas is introduced to raise the system pressure to 0.05~0.14 MPa; S3 Gradient heating polymerization stage: The system is heated to 280~320℃ at a rate of 5~10℃ / min, and the reaction is maintained under the positive pressure environment for 5~8 hours; S4 Post-processing stage: After the reaction is completed, the product is cooled, crushed, washed and dried to obtain polyether ether ketone resin.

2. The method for preparing polyetheretherketone resin by stepwise method according to claim 1, characterized in that, The inorganic base is potassium carbonate, the molar ratio of the inorganic base to hydroquinone is 1.05:1 to 1.15:1, and the molar ratio of 4,4'-difluorobenzophenone to hydroquinone is 1:1 to 1.02:

1.

3. The method for preparing polyetheretherketone resin by stepwise method according to claim 1, characterized in that, The inert aprotic solvent is diphenyl sulfone, and its amount is 150-300% of the total mass of the hydroquinone and the 4,4'-difluorobenzophenone.

4. The method for preparing polyetheretherketone resin by stepwise method according to claim 1, characterized in that, In step S1, the negative pressure is -0.07 ~ -0.08 MPa.

5. The method for preparing polyetheretherketone resin by stepwise method according to claim 1, characterized in that, In step S2, the system pressure is increased to 0.1~0.14 MPa.

6. A polyetheretherketone resin preparation system for carrying out the method according to any one of claims 1-5, characterized in that, include: The reaction vessel unit includes a reactor (5), a first condensation reaction tower (3), and a second condensation reaction tower (4). The first condensation reaction tower (3) and the second condensation reaction tower (4) are selectively connected to the top gas phase outlet of the reactor (5) through a first connecting valve (1) and a second connecting valve (2), respectively. The vacuum unit includes a main vacuum pipeline (6), a first vacuum branch (7), and a second vacuum branch (8). The main vacuum pipeline (6) is connected to an external vacuum source. The first vacuum branch (7) and the second vacuum branch (8) respectively connect the main vacuum pipeline (6) to the first vacuum interface (9) of the first condensation reaction tower (3) and the second vacuum interface (10) of the second condensation reaction tower (4). The gas replacement and pressure control unit includes an inert gas main pipeline (16), a main inert gas branch (15), a first inert gas branch (11), and a second inert gas branch (12). The main inert gas branch (15) is connected to the reactor (5). The inert gas main pipeline (16) is connected to the first replacement port (13) of the first condensing reaction tower (3) and the second replacement port (14) of the second condensing reaction tower (4) through the first inert gas branch (11) and the second inert gas branch (12), respectively. Heating devices are provided on the first inert gas branch (11) and the second inert gas branch (12). The control system is a programmable logic controller or a distributed control system, which is connected to the control valves on the first connecting valve (1), the second connecting valve (2), the first vacuum interface (9), the second vacuum interface (10), the first displacement interface (13), the second displacement interface (14), and the main inert gas branch (15) respectively. The control system is configured to sequentially execute pressure and process control operations corresponding to steps S1 to S3 of claim 1 by controlling the opening and closing of the valves described above.

7. The polyetheretherketone resin preparation system according to claim 6, characterized in that, The control system is further configured to run an alternating vacuuming and displacement cycle program when performing the operation corresponding to step S1, with each cycle executing the following steps in sequence: (a) Open the first connecting valve (1) and the first vacuum port (9), close the second connecting valve (2), the first replacement port (13) and the second replacement port (14), so that the reactor (5) is connected to the vacuum unit through the first condensation reaction tower (3) to perform vacuum dehydration for a first set time T1. (b) Open the second connecting valve (2) and the second vacuum port (10), then close the first vacuum port (9) and open the first replacement port (13); after the pressure stabilizes, close the first connecting valve (1); switch the reactor (5) to be connected to the vacuum unit through the second condensation reaction tower (4), continue to evacuate and dehydrate, and continue for a third set time T3; at the same time, introduce heated inert gas into the first condensation reaction tower (3) through the first replacement port (13) for purging and replacement; (c) Open the first connecting valve (1) and the first vacuum port (9), then close the second vacuum port (10) and open the second displacement port (14); after the pressure stabilizes, close the second connecting valve (2); the system state returns to step (a) to enter the next cycle; at the same time, heated inert gas is introduced into the second condensation reaction tower (4) through the second displacement port (14) for purging and displacement.

8. The polyetheretherketone resin preparation system according to claim 7, characterized in that, The first set time T1 and the third set time T3 are both 7 minutes, and the waiting time after the pressure stabilizes in steps (b) and (c) is 3 minutes; and the main inert gas branch (15) is equipped with a flow regulating valve for continuously introducing inert gas into the reactor (5) at a flow rate of 1-5 liters / minute in steps S2 and S3.

9. A polyetheretherketone resin prepared by the method according to any one of claims 1-5, characterized in that, The polyetheretherketone resin has a number-average molecular weight of 30,000 to 50,000 g / mol, a molecular weight distribution of less than or equal to 2.0, and a glass transition temperature of greater than or equal to 143°C.

10. The application of the polyetheretherketone resin according to claim 9 in high-performance engineering plastic products.

Images