Modified polyether ether ketone material for aerospace initiating explosive devices and method of making same

Abstract

The application provides a modified polyether ether ketone material for aerospace pyrotechnic devices and a preparation method thereof, the modified polyether ether ketone material is polymerized by 4,4-difluorobenzophenone, 2,6-dichlorobenzonitrile, phenolphthalein and potassium hydroquinone sulfonate; the molar ratio of 4,4-difluorobenzophenone, 2,6-dichlorobenzonitrile, phenolphthalein and potassium hydroquinone sulfonate is (1.5-4.5):(10-14):(3.5-6.5):(8-12), and the sum of the amount of substance of 4,4-difluorobenzophenone and 2,6-dichlorobenzonitrile is equal to the sum of the amount of substance of phenolphthalein and potassium hydroquinone sulfonate. The application improves the mechanical strength, temperature resistance and pressure resistance of the PEEK material by introducing a functional group, improves the interface compatibility of the PEEK material and metal material, thereby improving the sealing performance of the aerospace pyrotechnic device, and improves the flowability of the PEEK.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, and specifically relates to a modified polyether ether ketone material for aerospace pyrotechnic devices and its preparation method. Background Technology

[0002] With the increasing number of space missions in my country, such as the launch of high-orbit satellites and the operation and maintenance of space stations, pyrotechnic devices are required to withstand extreme environments such as extremely high and low temperatures, large temperature fluctuations, and solar radiation. Some structures place high demands on the compressive strength, sealing performance, insulation, and high-temperature resistance of materials, which conventional materials often struggle to simultaneously achieve. In particular, some non-metallic materials currently used in components, such as glass fiber-modified phenolic resin, generally exhibit low heat resistance and impact resistance, and their processing methods suffer from high energy consumption and pollution. Furthermore, when applied to the sealing structures of pyrotechnic devices, the high temperatures and impact coupling conditions generated during operation may induce a decrease in the product's sealing performance, making it difficult for the product to meet the high sealing requirements after ignition.

[0003] Polyarylether polymers are typical representatives of commercially available thermoplastic specialty engineering plastics, with polyetheretherketone (PEEK) being the most noteworthy. PEEK is a polymer composed of repeating units containing one ketone bond and two ether bonds in its main chain structure. It is a linear aromatic polymer compound with numerous benzene rings, exhibiting excellent processing properties and ease of injection molding, extrusion molding, and machining. It is one of the top-tier specialty engineering plastics with the best overall performance. PEEK has been widely used in cutting-edge fields such as aerospace, electronics, medical devices, and nuclear power generation. Especially in the aerospace field, PEEK can replace aluminum and other metal materials in the manufacture of aircraft parts, reducing weight by up to 70% compared to metals. In addition, the European Space Agency, in collaboration with the Portuguese polymer engineering company PIEP, launched a 3D-printed PEEK-based small satellite product, which successfully passed commercial testing. Meanwhile, PEEK injection-molded radomes, fasteners, aerospace fuel tanks, and other components are gradually becoming mainstream products in the industry.

[0004] Although polyarylene ether specialty polymer materials have been successfully applied in the aerospace field, their application in the field of aerospace pyrotechnic devices, known as the "heart of thermal weapons," is still in its infancy. Moreover, in limited non-critical applications, foreign companies' polyarylene ether raw materials (such as PEEK and PEI) and finished parts are generally used, resulting in a low degree of self-control. At the same time, existing PEEK materials still need to be modified to meet the performance requirements of pyrotechnic devices in terms of pressure resistance, sealing, insulation, and high temperature resistance.

[0005] Therefore, it is necessary to design formulations to meet the requirements of aerospace pyrotechnic devices in extreme environments such as extremely high and low temperatures, large temperature fluctuations, and solar radiation, and to solve the problem of limited application of existing PEEK materials in aerospace pyrotechnic devices. The main points are as follows:

[0006] (1) The metal compatibility of pure PEEK material cannot meet the airtightness requirements when applied to aerospace pyrotechnic devices.

[0007] (2) The mechanical strength of pure PEEK material cannot meet the temperature and pressure resistance requirements of aerospace pyrotechnic devices at the moment of ignition.

[0008] (3) Pure PEEK material has insufficient flowability when used in aerospace pyrotechnic devices. Summary of the Invention

[0009] In order to overcome the shortcomings of the prior art, the inventors have conducted intensive research and provided a modified polyetheretherketone (PEEK) material for aerospace pyrotechnic devices and its preparation method. By introducing functional groups, the mechanical strength, temperature resistance and pressure resistance of PEEK material are improved, the interfacial compatibility between PEEK material and metal material is enhanced, thereby improving the sealing performance of aerospace pyrotechnic devices and improving the flowability of PEEK.

[0010] The technical solution provided by this invention is as follows:

[0011] In one aspect, a method for preparing a modified polyetheretherketone (PEEK) material is disclosed, using phenolphthalein and potassium hydroquinone sulfonate as phenol sources, and combining them with 4,4-difluorobenzophenone and 2,6-dichlorobenzonitrile, to synthesize a modified PEEK-NS polyetheretherketone sulfonate copolymer with cyano and sulfonic acid groups via nucleophilic condensation polymerization. The method includes:

[0012] 4,4-Difluorobenzophenone, 2,6-dichlorobenzonitrile, phenolphthalein, potassium hydroquinone sulfonate, catalyst and organic solvent are mixed in a reactor;

[0013] The reaction system was heated to carry out a polycondensation reaction to synthesize crude modified polyether ether ketone material;

[0014] The crude modified polyether ether ketone material was purified to obtain the purified modified polyether ether ketone material.

[0015] Secondly, a modified polyetheretherketone material is polymerized from 4,4-difluorobenzophenone, 2,6-dichlorobenzonitrile, phenolphthalein, and potassium hydroquinone sulfonate.

[0016] The molar ratio of 4,4-difluorobenzophenone, 2,6-dichlorobenzonitrile, phenolphthalein, and potassium hydroquinone sulfonate is (1.5–4.5):(10–14):(3.5–6.5):(8–12), and the sum of the amounts of 4,4-difluorobenzophenone and 2,6-dichlorobenzonitrile is equal to the sum of the amounts of phenolphthalein and potassium hydroquinone sulfonate.

[0017] The modified polyetheretherketone material for aerospace pyrotechnic devices and its preparation method provided by the present invention have the following beneficial effects:

[0018] (1) The present invention provides a modified polyether ether ketone material for aerospace pyrotechnic devices and its preparation method, using phenolphthalein and potassium hydroquinone sulfonate as phenol sources. Phenolphthalein has a twisted non-planar structure and large steric hindrance, which makes the copolymer non-crystallizing and has better flowability during injection molding, thus solving the problem of insufficient flowability of pure PEEK during injection molding of complex aerospace pyrotechnic devices;

[0019] (2) The present invention provides a modified polyether ether ketone material for aerospace pyrotechnic devices and its preparation method. By introducing sulfonic acid groups in the synthesis modification of potassium hydroquinone sulfonate, which are polar groups and easy to graft, they can be connected to other interfaces during use, thereby improving the interfacial compatibility. This solves the problem of insufficient sealing performance caused by low interfacial compatibility of pure PEEK when used in aerospace pyrotechnic devices. Through modification, the aerospace pyrotechnic device made can achieve the sealing requirement of 29.5 MPa / 1min without leakage when tested by the bubble method, while pure PEEK material can only achieve 19 MPa / 1min without leakage. Glass fiber modified phenolic resin can meet the requirement of 25 MPa / 1min without leakage for aerospace pyrotechnic devices, but it is difficult to meet the requirement of 29 MPa / 1min for aerospace pyrotechnic devices used in manned spaceflight.

[0020] (3) The present invention provides a modified polyether ether ketone material for aerospace pyrotechnic devices and its preparation method. In the synthesis, cyano groups are introduced. When heated, cyano groups can crosslink with other groups to form a network structure, which helps to improve the temperature resistance. Its glass transition temperature is about 236°C and it can be used for a long time in the range of 300°C. At the same time, the cyano group has large steric hindrance, which also helps to improve the flowability during processing. Attached Figure Description

[0021] Figure 1 This is a schematic diagram illustrating the synthesis of a PEEK material modification method for aerospace pyrotechnic devices according to the present invention;

[0022] Figure 2 This is the infrared spectrum of the modified PEEK material prepared in Example 1 of this invention;

[0023] Figure 3This is a DSC curve of the modified PEEK material prepared in Example 1 of this invention;

[0024] Figure 4 This is a TGA curve of the modified PEEK material prepared in Example 1 of this invention;

[0025] Figure 5 This is a graph showing the intrinsic viscosity of the modified PEEK material prepared in Example 1 of this invention as a function of time. Detailed Implementation

[0026] The features and advantages of the present invention will become clearer and more apparent from the following detailed description.

[0027] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0028] This invention provides a method for modifying polyetheretherketone (PEEK) materials, comprising the following steps:

[0029] Step one involves mixing 4,4-difluorobenzophenone, 2,6-dichlorobenzonitrile, phenolphthalein, potassium hydroquinone sulfonate (potassium 2,5-dihydroxybenzenesulfonate), catalyst, and organic solvent in a reactor. In this step, 2,6-difluorobenzonitrile can be used instead of 2,6-dichlorobenzonitrile.

[0030] In this step, the molar ratio of 4,4-difluorobenzophenone, 2,6-dichlorobenzonitrile, phenolphthalein, and potassium hydroquinone sulfonate is (1.5–4.5):(10–14):(3.5–6.5):(8–12), and the sum of the amounts of 4,4-difluorobenzophenone and 2,6-dichlorobenzonitrile is equal to the sum of the amounts of phenolphthalein and potassium hydroquinone sulfonate.

[0031] Preferably, the molar ratio of 4,4-difluorobenzophenone, 2,6-dichlorobenzonitrile, phenolphthalein, and potassium hydroquinone sulfonate is (2-4):(11-13):(4-6):(9-11), and the sum of the amounts of 4,4-difluorobenzophenone and 2,6-dichlorobenzonitrile is equal to the sum of the amounts of phenolphthalein and potassium hydroquinone sulfonate.

[0032] More preferably, the molar ratio of 4,4-difluorobenzophenone, 2,6-dichlorobenzonitrile, phenolphthalein, and potassium hydroquinone sulfonate is (2.5–3.5):(11.5–12.5):(4.5–5.5):(9.5–10.5), such as 3:12:5:10, and the sum of the amounts of 4,4-difluorobenzophenone and 2,6-dichlorobenzonitrile is equal to the sum of the amounts of phenolphthalein and potassium hydroquinone sulfonate.

[0033] In this step, the catalyst is selected from at least one of potassium carbonate (K2CO3) and sodium carbonate (Na2CO3), with potassium carbonate (K2CO3) being preferred.

[0034] In this step, the organic solvent includes a first solvent and a second solvent. The first solvent is selected from at least one polar aprotic solvent such as N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), dimethylacetamide (DMAc), and sulfolane. The second solvent is selected from a combination of at least one of toluene and xylene, such as a combination of NMP and toluene. Preferably, the volume ratio of the first solvent to the second solvent is (2-4):1, such as 3:1.

[0035] In this step, the total mass of 4,4-difluorobenzophenone, 2,6-dichlorobenzonitrile, phenolphthalein, and potassium hydroquinone sulfonate is in the mass ratio of catalyst and organic solvent to 70:(25-50):(80-140), such as 70:32:99.

[0036] Step two: After assembling a water separation device on the reactor, the reaction system is heated to carry out a prepolymerization reaction. During the reaction, the generated water is separated until the dehydration is completed. The reaction rate is accelerated by continuously separating the generated water in the system.

[0037] In this step, the reactor is equipped with a thermometer, a stirrer, and a water separator. During the reaction, the reactor is stirred and the reaction temperature is monitored. The water separator includes a water separator and a condenser. After the water separator with an appropriate amount of toluene and the condenser connected to cold water are installed on the reaction apparatus and sealed, the condensation reaction is started.

[0038] In this step, the prepolymerization reaction temperature is 150–160°C, such as 155°C.

[0039] Step 3: The reaction system is heated to carry out a polycondensation reaction to synthesize crude modified polyetheretherketone material. See the schematic diagram for the synthesis. Figure 1 .

[0040] In this step, the polycondensation reaction temperature is 185–190℃, and the reaction time is 1–4 hours.

[0041] Step four: Purify the crude modified polyether ether ketone material to obtain purified modified polyether ether ketone material (PEEK-NS).

[0042] The purification process in this step is as follows:

[0043] Step 4.1: Pour the crude modified polyetheretherketone material, which has been cooled to a suitable temperature (100-120℃), into anhydrous ethanol for precipitation and hardening for more than 12 hours;

[0044] Step 4.2: To remove unreacted monomers and catalyst, the precipitate is pulverized and then refluxed and heated in an acidic aqueous solution (5%–10% by mass) for at least 2 hours at a temperature of 80–100°C. The acidic aqueous solution is hydrochloric acid, sulfuric acid, or nitric acid. The pulverized precipitate is then washed sequentially with a volatile organic solvent and hot water, preferably acetone, ethanol, and hot water. Acetone and ethanol washings are performed at least once for 10 minutes each, and hot water washing is performed twice, each time for at least 0.5 hours. Finally, the product is dried in an oven at 100–130°C (e.g., 120°C) for at least 4 hours.

[0045] The present invention also provides a modified polyetheretherketone material, which is prepared by the above-described method for modifying polyetheretherketone materials.

[0046] Example

[0047] Example 1

[0048] A method for modifying PEEK materials for aerospace pyrotechnic devices includes the following steps:

[0049] Step 1: First, fix the 250mL three-necked flask equipped with a thermometer and stirrer onto the heating mantle, and weigh the raw materials and solvent (NMP + toluene) according to the ratio, adding them to the three-necked flask in sequence. The molar ratio of 4,4-difluorobenzophenone, 2,6-dichlorobenzonitrile, phenolphthalein, and potassium hydroquinone sulfonate is 0.03mol:0.12mol:0.05mol:0.1mol, K2CO3 is 31.8g, NMP is 75mL, and toluene is 25mL.

[0050] Step 2: Turn on the stirrer and raise the temperature to 155℃ for reflux dehydration. Observe the dehydration process during this step. After dehydration is complete, gradually raise the temperature to around 190℃ and continue stirring for 2 hours. Figure 5 It can be seen that the intrinsic viscosity is relatively stable after 2 hours of reaction, indicating that the polycondensation reaction is complete and a high molecular weight product, PEEK-NS, has been synthesized.

[0051] Step 3: The synthesized product, cooled to 120℃, was poured into anhydrous ethanol to precipitate and harden for 12 hours. The precipitated product was then pulverized using a pulverizer. To remove unreacted monomers and K2CO3, the pulverized product was refluxed and heated in a mixed solution of water and hydrochloric acid (8% by mass) for 2 hours. The product was then washed and filtered sequentially with acetone, ethanol, and hot water. Acetone and ethanol were washed once each for 10 minutes, and hot water was washed twice for 0.5 hours each time. After washing and filtration, the product was dried in an oven at 120℃ for 4 hours.

[0052] The infrared spectrum of the PEEK-NS prepared in Example 1 is shown below. Figure 2 It can be seen that PEEK-NS contains sulfonic acid groups (530cm). -1 1190cm -1 ) and cyano (2231cm) -1 Characteristic peaks; DSC curve (see) Figure 3 It can be seen that the glass transition temperature of PEEK-NS is 236℃. Furthermore, PEEK-NS has a melting point of 355℃, a viscosity of 3.1 dL / g, a melt index of 83 g / 10min at 400℃, a tensile strength of 121.8 MPa, a flexural modulus of 3.31 GPa, and an elongation at break of 11.2%. The 5% thermal decomposition temperature of PEEK-NS (T...) 5％ ) and 10% thermal decomposition temperature (T 10％ The temperatures exceeded 553℃ and 564℃ respectively, demonstrating excellent thermal stability. Figure 4 .

[0053] The PEEK-NS metal insert prepared in Example 1 was injection molded and installed into an aerospace pyrotechnic device. It exhibited a leak-proof sealing performance of 29.5 MPa / 1 min. After high and low temperature cycling tests, it ignited under heat preservation conditions. Helium mass spectrometry leak detection showed a leakage rate of less than 1 × 10⁻⁶. - 8 Pa·m 3 / s, sealing performance and ignition performance meet the requirements.

[0054] Examples 2-3 and Comparative Examples 1-4

[0055] A method for modifying PEEK materials for aerospace pyrotechnic devices includes the following steps:

[0056] Step 1: First, fix the 250mL three-necked flask equipped with a thermometer and stirrer onto the heating mantle, and weigh the raw materials and solvent (NMP + toluene) according to the ratio and add them to the three-necked flask in sequence. The molar ratios of 4,4-difluorobenzophenone, 2,6-dichlorobenzonitrile, phenolphthalein, and potassium hydroquinone sulfonate in Examples 2-3 and Comparative Examples 1-4 are shown in Table 1. K2CO3 is 31.8g, NMP is 75mL, and toluene is 25mL.

[0057] Table 1 Raw Material Proportions

[0058] Examples / Comparative Examples 4,4-Difluorobenzophenone 2,6-Dichlorobenzonitrile Phenolphthalein Potassium hydroquinone sulfonate Example 1 0.03 0.12 0.05 0.10 Example 2 0.02 0.11 0.04 0.09 Example 3 0.04 0.13 0.06 0.11 Comparative Example 1 0.01 0.14 0.05 0.10 Comparative Example 2 0.06 0.09 0.05 0.10 Comparative Example 3 0.03 0.12 0.02 0.13 Comparative Example 4 0.03 0.12 0.08 0.07

[0059] Step 2: Turn on the stirrer and raise the temperature to 155℃ for reflux dehydration. Observe the dehydration process here. After the dehydration is completed, gradually raise the temperature to between 190℃ and continue stirring for 2 hours to synthesize the high molecular weight product modified PEEK through polycondensation.

[0060] Step 3: Pour the synthesized product, cooled to 120℃, into anhydrous ethanol to harden and precipitate for 12 hours. Then, pulverize the precipitate using a pulverizer. To remove unreacted monomers and K2CO3, the pulverized product is refluxed and heated in a mixed solution of water and hydrochloric acid (8% by mass) for 2 hours. Then, it is washed and filtered in sequence with acetone, ethanol, and hot water. Acetone and ethanol are washed once for 10 minutes each, and hot water is washed twice for 0.5 hours each time. After washing and filtration, the product is placed in an oven at 120℃ and dried for 4 hours.

[0061] The results of Example 2 are as follows:

[0062] The PEEK-NS prepared in Example 2 contains sulfonic acid groups (530cm). -1 1190cm -1 ) and cyano (2231cm) -1 The characteristic peaks of PEEK-NS are as follows: glass transition temperature is 238℃, melting point is 359℃, viscosity is 3.2 dL / g, melt index at 400℃ is 80 g / 10 min, tensile strength is 119.3 MPa, flexural modulus is 3.32 GPa, elongation at break is 10.8%, and the 5% thermal decomposition temperature (T0) of PEEK-NS is also observed. 5％ ) and 10% thermal decomposition temperature (T 10％ The temperatures exceeded 554℃ and 564℃ respectively, demonstrating excellent thermal stability.

[0063] The PEEK-NS prepared in Example 2 was injection-molded into a metal insert and installed in an aerospace pyrotechnic device. It exhibited a leak-free sealing performance of 27.3 MPa / 1 min. After high and low temperature cycling tests, it ignited under heat preservation conditions. Helium mass spectrometry leak detection showed a leakage rate of less than 1 × 10⁻⁶. - 8 Pa·m 3 / s, sealing performance and ignition performance meet the requirements.

[0064] The results of Example 3 are as follows:

[0065] The PEEK-NS prepared in Example 3 contains sulfonic acid groups (530cm). -1 1190cm -1 ) and cyano (2231cm) -1 The characteristic peaks of PEEK-NS are observed, and its glass transition temperature is 228℃. Furthermore, PEEK-NS has a melting point of 348℃, a viscosity of 2.9 dL / g, a melt index of 88 g / 10 min at 400℃, a tensile strength of 118.8 MPa, a flexural modulus of 3.23 GPa, and an elongation at break of 11.5%. The 5% thermal decomposition temperature (T5) of the obtained PEEK-NS is also shown. 5％ ) and 10% thermal decomposition temperature (T 10％The temperatures exceeded 531℃ and 546℃ respectively, demonstrating excellent thermal stability.

[0066] The PEEK-NS metal insert prepared in Example 3 was injection molded and installed into an aerospace pyrotechnic device. It exhibited a leak-free sealing performance of 27.8 MPa / 1 min. After high and low temperature cycling tests, it ignited under heat preservation conditions. Helium mass spectrometry leak detection showed a leakage rate of less than 1 × 10⁻⁶. - 8 Pa·m 3 / s, sealing performance and ignition performance meet the requirements.

[0067] The results of Comparative Example 1 are as follows:

[0068] The PEEK-NS prepared in Comparative Example 1 contains sulfonic acid groups (530cm). -1 1190cm -1 ) and cyano (2231cm) -1 The characteristic peaks of PEEK-NS are observed, and its glass transition temperature is 202℃. Furthermore, PEEK-NS has a melting point of 325℃, a viscosity of 2.6 dL / g, a melt index of 92 g / 10 min at 400℃, a tensile strength of 92.5 MPa, a flexural modulus of 2.84 GPa, and an elongation at break of 8.5%. The 5% thermal decomposition temperature (T5) of the obtained PEEK-NS is also shown. 5％ ) and 10% thermal decomposition temperature (T 10％ The temperatures exceeded 489℃ and 501℃ respectively, demonstrating excellent thermal stability.

[0069] The PEEK-NS prepared in Comparative Example 1 was injection-molded into a metal insert and installed in an aerospace pyrotechnic device. It exhibited a leak-free sealing performance of 22 MPa / 1 min, and after high and low temperature cycling tests, it ignited under heat preservation. Helium mass spectrometry leak detection showed a leakage rate greater than 1 × 10⁻⁶. -8 Pa·m 3 / s, sealing performance and ignition performance do not meet the requirements.

[0070] The results of Comparative Example 2 are as follows:

[0071] The PEEK-NS prepared in Comparative Example 2 contains sulfonic acid groups (530cm). -1 1190cm -1 ) and cyano (2231cm) -1 The characteristic peaks of PEEK-NS are observed, and its glass transition temperature is 212℃. Furthermore, PEEK-NS has a melting point of 332℃, a viscosity of 2.7 dL / g, a melt index of 90 g / 10 min at 400℃, a tensile strength of 98.9 MPa, a flexural modulus of 2.99 GPa, and an elongation at break of 9.3%. The 5% thermal decomposition temperature (T5) of the obtained PEEK-NS is also shown. 5％ ) and 10% thermal decomposition temperature (T 10％The temperatures exceeded 503℃ and 515℃ respectively, demonstrating excellent thermal stability.

[0072] The PEEK-NS prepared in Comparative Example 2 was injection-molded into a metal insert and installed in an aerospace pyrotechnic device. It exhibited a leak-free sealing performance of 21 MPa / 1 min, and after high and low temperature cycling tests, it ignited under heat preservation. Helium mass spectrometry leak detection showed a leakage rate greater than 1 × 10⁻⁶. -8 Pa·m 3 / s, sealing performance and ignition performance do not meet the requirements.

[0073] The results of Comparative Example 3 are as follows:

[0074] The PEEK-NS prepared in Comparative Example 3 contained sulfonic acid groups (530cm). -1 1190cm -1 ) and cyano (2231cm) -1 The characteristic peaks of PEEK-NS are observed, and its glass transition temperature is 223℃. Furthermore, PEEK-NS has a melting point of 338℃, a viscosity of 2.7 dL / g, a melt index of 55 g / 10 min at 400℃, a tensile strength of 111.2 MPa, a flexural modulus of 3.02 GPa, and an elongation at break of 9.5%. The 5% thermal decomposition temperature (T5) of the obtained PEEK-NS is also described. 5％ ) and 10% thermal decomposition temperature (T 10％ The temperatures exceeded 528℃ and 539℃ respectively, demonstrating excellent thermal stability.

[0075] The PEEK-NS prepared in Comparative Example 3 was injection-molded into a metal insert and installed in an aerospace pyrotechnic device. Due to its poor flowability and surface quality, it exhibited a leak-free sealing performance of 15 MPa / 1 min. After high and low temperature cycling tests, it ignited under heat preservation, and helium mass spectrometry leak detection showed a leakage rate greater than 1 × 10⁻⁶. -8 Pa·m 3 / s, sealing performance and ignition performance do not meet the requirements.

[0076] The results of Comparative Example 4 are as follows:

[0077] The PEEK-NS prepared in Comparative Example 4 contains sulfonic acid groups (530cm). -1 1190cm -1 ) and cyano (2231cm) -1 The characteristic peaks of PEEK-NS are observed, and its glass transition temperature is 227℃. Furthermore, PEEK-NS has a melting point of 342℃, a viscosity of 2.8 dL / g, a melt index of 88 g / 10 min at 400℃, a tensile strength of 102.3 MPa, a flexural modulus of 3.06 GPa, and an elongation at break of 10.3%. The 5% thermal decomposition temperature (T5) of the obtained PEEK-NS is also described. 5％ ) and 10% thermal decomposition temperature (T10％ The temperatures exceeded 522℃ and 531℃ respectively, demonstrating excellent thermal stability.

[0078] The PEEK-NS prepared in Comparative Example 4 was injection-molded into a metal insert and installed in an aerospace pyrotechnic device. It exhibited a leak-free sealing performance of 17 MPa / 1 min, and after high and low temperature cycling tests, it ignited under heat preservation. Helium mass spectrometry leak detection showed a leakage rate greater than 1 × 10⁻⁶. -8 Pa·m 3 / s, sealing performance and ignition performance do not meet the requirements.

[0079] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0080] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A modified polyetheretherketone material, characterized in that, It is produced by polymerization of 4,4-difluorobenzophenone, 2,6-dichlorobenzonitrile, phenolphthalein and potassium hydroquinone sulfonate; The molar ratio of 4,4-difluorobenzophenone, 2,6-dichlorobenzonitrile, phenolphthalein, and potassium hydroquinone sulfonate is (1.5~4.5):(10~14):(3.5~6.5):(8~12), and the sum of the amounts of 4,4-difluorobenzophenone and 2,6-dichlorobenzonitrile is equal to the sum of the amounts of phenolphthalein and potassium hydroquinone sulfonate.

2. A method for preparing a modified polyetheretherketone material, characterized in that, include: 4,4-Difluorobenzophenone, 2,6-dichlorobenzonitrile, phenolphthalein, potassium hydroquinone sulfonate, catalyst and organic solvent are mixed in a reactor; The reaction system was heated to carry out a polycondensation reaction to synthesize crude modified polyether ether ketone material; The crude modified polyether ether ketone material was purified to obtain the purified modified polyether ether ketone material.

3. The method for preparing the modified polyetheretherketone material according to claim 2, characterized in that, The catalyst is selected from at least one of potassium carbonate (K2CO3) and sodium carbonate (Na2CO3).

4. The method for preparing the modified polyetheretherketone material according to claim 2, characterized in that, The organic solvent includes a first solvent and a second solvent, wherein the first solvent is selected from at least one of N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), dimethylacetamide (DMAc), and sulfolane, and the second solvent is selected from a combination of at least one of toluene and xylene.

5. The method for preparing the modified polyetheretherketone material according to claim 4, characterized in that, The volume ratio of the first solvent to the second solvent is (2~4):

1.

6. The method for preparing the modified polyetheretherketone material according to claim 2, characterized in that, The total mass of the 4,4-difluorobenzophenone, 2,6-dichlorobenzonitrile, phenolphthalein, and potassium hydroquinone sulfonate is in a mass ratio of 70:(25~50):(80~140) to the catalyst and organic solvent.

7. The method for preparing the modified polyetheretherketone material according to claim 2, characterized in that, Before the reaction system is heated to carry out a polycondensation reaction to synthesize the crude modified polyether ether ketone material, the process further includes: heating the reaction system to carry out a prepolymerization reaction, and separating the water generated during the reaction until the dehydration is completed.

8. The method for preparing the modified polyetheretherketone material according to claim 7, characterized in that, The prepolymerization reaction temperature is 150~160℃.

9. The method for preparing the modified polyetheretherketone material according to claim 2, characterized in that, The polycondensation reaction temperature is 185~190℃.

10. The method for preparing the modified polyetheretherketone material according to claim 2, characterized in that, The step of purifying the crude modified polyetheretherketone material includes: The cooled modified polyether ether ketone material crude product was poured into anhydrous ethanol for precipitation and hardening; The precipitate was crushed, washed sequentially with acidic aqueous solution, organic solvent and hot water, and dried to obtain purified modified polyether ether ketone material.

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