A high-toughness polyether ketone ketone polymer and its preparation method
By introducing flexible polyether side chains into the PEKK polymer main chain, the problems of harsh conditions and high cost in the traditional PEKK preparation process are solved, and the flexibility and rigidity of high-toughness PEKK polymers are achieved, and the performance of the material is improved.
Patent Information
- Application Number
- CN202510494877.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-21
- Publication Date
- 2025-07-18
- Estimated Expiration
- 2045-04-21
AI Technical Summary
The existing PEKK preparation process has problems such as harsh conditions, complex synthesis process, expensive monomer prices and many side reactions, resulting in high production costs and limiting its wide application.
By introducing a highly tough polyether ketone ketone polymer with a flexible polyether side chain, a high tough PEKK polymer is prepared by reacting diphenyl ether, terephthalyl chloride with a molar ratio of 1:a: (1-a): (3~5), compound 1 and anhydrous aluminum trichloride, to prepare a highly tough PEKK polymer, where compound 1 isophthalyl chloride with a flexible polyether side chain, and the value of a is 0.5~0.9.
The harmonious unity of flexibility and rigidity in the polymer main chain is achieved, the flexibility of the polymer is improved, the glass transition temperature and melting temperature are reduced, and the elongation of break is improved.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of high molecular special engineering plastics, and particularly relates to a high-toughness polyether ketone ketone polymer and a preparation method thereof. Background Art
[0002] Advanced materials are an important material basis for the development of science and technology. High-performance resin-based composites have become one of the high-tech materials in development due to their light weight, high specific strength, high specific modulus, high temperature resistance, and excellent performance designability. Their applications in industries such as aerospace also show unique advantages and potential. Currently, general high-performance resin matrices can usually be divided into two categories: thermoplastic and thermosetting resins. Typical high-performance thermoplastic resins include thermoplastic polyimide, polyamide, polyethersulfone, liquid crystal polyester, polyaryletherketone, etc. Among them, polyaryletherketone (PEAK) special engineering plastics have excellent mechanical and physical properties. Compared with other high-temperature-resistant plastics, PEAK is currently the variety with the highest heat resistance grade and the best comprehensive performance among special engineering plastics, and its long-term heat resistance exceeds 250 °C. In addition, PEAK also has excellent self-lubricity, flame retardancy, and chemical resistance, etc. The excellent comprehensive performance of PEAK makes it widely used in fields such as the automotive industry, aerospace, electronic information, and conveying pipelines.
[0003] PEAK can be divided into polyether ketone (PEK), polyether ether ketone (PEEK), polyether ketone ketone (PEKK), etc. according to the monomer sequence of its main chain. In recent years, PEKK has great research value and application prospects due to its higher mechanical and high-temperature resistance characteristics. PEKK and its composites are polymers with a repeating unit containing 2 ketone bonds and 1 ether bond in the main chain, which are different from and superior to PEEK. Among them, the three benzene rings in the smallest repeating unit composed of 2 ketone bonds and 1 ether bond form a super large π bond. This structural feature makes PEKK a leader among all high-performance thermoplastic polymer materials. It has excellent mechanical properties, solvent and chemical corrosion resistance, radiation resistance, and flame retardancy, etc. These characteristics make it particularly suitable as the resin matrix of high-performance composites and super engineering plastics.
[0004] The currently reported PEKK preparation processes are mainly divided into two types: nucleophilic substitution and electrophilic substitution. Among them, the side reactions such as branching and crosslinking in nucleophilic substitution are relatively easy to control. However, the reaction conditions are harsh (usually carried out at a temperature >300 °C), the synthesis process is complex, the monomer price is expensive, and the production cost is high, which restricts the wide application of this method. The conditions for electrophilic substitution are relatively mild and the raw materials are cheaper. However, there are also disadvantages such as many side reactions, a large amount of catalyst used, and a cumbersome post-treatment process. The currently common electrophilic substitution polymerization processes mostly use diphenyl ether and p / m-phthaloyl chloride as comonomers and Lewis acid / base as catalysts to carry out polycondensation reactions at low temperature to room temperature (CN106800649B, CN109608627B, CN109608626B, CN109593183B, CN107973902B). Therefore, through molecular design, developing new structure PEKK polymers with high performance and their preparation processes has important practical significance. Summary of the Invention
[0005] Technical problems to be solved: Aiming at the above technical problems, the present invention provides a high-toughness polyether ketone ketone polymer and its preparation method, which can effectively solve the problems that the reaction conditions such as branching and crosslinking in nucleophilic substitution are harsh (usually carried out at a temperature >300 °C), the synthesis process is complex, the monomer price is expensive, and the production cost is high, thus restricting the wide application of this method; and the disadvantages of many side reactions, a large amount of catalyst used, and a cumbersome post-treatment process in electrophilic substitution.
[0006] Technical solution: In the first aspect, the present invention provides a high-toughness polyether ketone ketone polymer, and the structural general formula of the high-toughness polyether ketone ketone polymer is as follows:
[0007] ,
[0008] wherein, when the carbonyl group at the rightmost end of the structural formula is in the para position, X is H; when the carbonyl group at the rightmost end of the structural formula is in the meta position, X is O(CH2CH2O) m H, m is an integer from 10 to 100; n is an integer from 10 to 10,000.
[0009] In the second aspect, the present invention provides a preparation method of the high-toughness polyether ketone ketone polymer described in the first aspect. The high-toughness polyether ketone ketone polymer is obtained by reacting diphenyl ether, p-phthaloyl chloride, compound 1 and anhydrous aluminum trichloride in a molar ratio of 1:a:(1 - a):(3 - 5), where the value of a is 0.5 - 0.9, and the compound 1 is m-phthaloyl chloride with a flexible polyether side chain.
[0010] Preferably, the structural general formula of the compound 1 is as follows:
[0011] ,
[0012] Among them, m is an integer from 10 to 100.
[0013] Furthermore, the compound 1 is realized by using reaction types well-known in the art. The specific process is as follows:
[0014] Step 1: Place 3,5-dimethylphenol and a catalyst in a high-pressure reactor, introduce ethylene oxide at 120 - 140 °C, and react for 1 - 3 hours to obtain compound 2;
[0015] The catalyst is sodium hydride, sodium methoxide or sodium tert-butoxide;
[0016] The molar ratio of the 3,5-dimethylphenol, the catalyst, and ethylene oxide is 1:(0.01 - 0.1):m;
[0017] Step 2: Dissolve compound 2 and potassium permanganate in a mixed solution of pyridine and water with a volume ratio of 1:1, react at 90 - 110 °C for 6 - 10 hours, then filter. Adjust the filtrate to acidic with dilute hydrochloric acid, filter the precipitated solid, wash it with water, and dry it to obtain compound 3;
[0018] The molar ratio of compound 2 to potassium permanganate is 1:(2 - 4);
[0019] Step 3: Dissolve compound 3, pyridine, and thionyl chloride in tetrahydrofuran, react at room temperature for 2 - 4 hours, and remove the solvent by vacuum distillation to obtain compound 1;
[0020] The molar ratio of compound 3, pyridine, and thionyl chloride is 1:(0.01 - 0.1):(2 - 4);
[0021] The synthesis route of the compound 1 is as follows:
[0022] .
[0023] Preferably, the specific process of the preparation method of the high-toughness polyether ketone ketone polymer is as follows:
[0024] S1: Mix diphenyl ether, anhydrous aluminum trichloride, and an organic solvent in a reaction kettle, cool the reaction system to -10 - -30 °C, and bubble with an inert gas for 0.5 - 1.5 h to obtain solution A;
[0025] S2: Dissolve the mixture of terephthaloyl chloride and compound 1 in an organic solvent to obtain solution B;
[0026] S3. Slowly add solution B dropwise to solution A under the protection of an inert gas. The addition is completed within 1 - 3 h. Maintain the reaction at a low temperature of -10~-30 °C for 8 - 16 h, and then raise the temperature to room temperature and continue the reaction for 8 - 16 h;
[0027] S4. Filter to remove the organic solvent. Wash the obtained solid 3 - 5 times with a mixed solution of HCl aqueous solution and ethanol, and then wash it 1 - 3 times with water. After drying, a PEKK polymer is obtained; wherein the volume percentage concentration of the HCl aqueous solution is 5 - 20%, and the volume ratio of the HCl aqueous solution to ethanol is 1:0.2 - 0.5.
[0028] Further, the organic solvent is any one of dichloromethane, dichloroethane, chloroform, and o-dichlorobenzene.
[0029] Further, the inert gas is nitrogen or argon.
[0030] Beneficial effects: In the high-toughness PEKK polymer of the present invention, flexible polyether side chains are introduced into the rigid polymer main chain. Compared with the traditional PEKK polymer molecules with a pure rigid structure, it shows better flexibility, achieving the harmonious unity of strength, rigidity, and flexibility. Specific embodiments
[0031] The present invention will be described in detail below with reference to specific embodiments:
[0032] All the materials used in the examples are commercially available products. All the chemical reagents (analytical grade) used in the synthesis of the PEKK polymer are purchased from Anajaki Technology Co., Ltd., and the organic solvents (analytical grade) are purchased from Sinopharm Chemical Reagent Co., Ltd.
[0033] Synthesis Example 1
[0034] Place 0.1 mol of 3,5-dimethylphenol and 1 mmol of sodium hydride in a high-pressure reaction kettle. Introduce 1 mol of ethylene oxide at 120 °C and react for 1 hour to obtain compound 2; dissolve 0.1 mol of compound 2 and 0.2 mol of potassium permanganate in 200 mL of a mixed solution of pyridine and water with a volume ratio of 1:1. After reacting at 90 °C for 6 hours, filter. Adjust the filtrate to acidic with dilute hydrochloric acid. Filter, wash with water, and dry the precipitated solid to obtain compound 3; dissolve 0.1 mol of compound 3, 1 mmol of pyridine, and 0.2 mol of thionyl chloride in 200 mL of tetrahydrofuran. React at room temperature for 2 hours, and remove the solvent by distillation under reduced pressure to obtain compound 1 (m = 10);
[0035] 0.2 mol of diphenyl ether, 0.6 mol of anhydrous aluminum trichloride and 800 g of dichloroethane were mixed in a reaction kettle. The reaction system was cooled to -10 °C and bubbled with nitrogen for 0.5 h to obtain solution A; 0.18 mol of terephthaloyl chloride and 0.02 mol of compound 1 (m = 10) were dissolved in 400 g of dichloroethane to obtain solution B; solution B was slowly added dropwise to solution A under nitrogen protection and added dropwise within 1 h. The low-temperature reaction was maintained for 8 h, and then the temperature was raised to room temperature and the reaction continued for 8 h; the organic solvent was removed by filtration, and the obtained solid was washed 3 times with a mixed solution of 5% (volume fraction) HCl aqueous solution and ethanol in a volume ratio of 1:0.2, and then washed with water once. After drying, PEKK polymer 1 (m = 10, the molar ratio of terephthaloyl chloride to compound 1 was 9:1) was obtained.
[0036] Synthesis Example 2
[0037] 0.1 mol of 3,5-dimethylphenol and 1 mmol of sodium methoxide were placed in a high-pressure reaction kettle, and 5 mol of ethylene oxide was introduced at 130 °C and reacted for 2 h to obtain compound 2; 0.1 mol of compound 2 and 0.3 mol of potassium permanganate were dissolved in 200 mL of a mixed solution of pyridine and water with a volume ratio of 1:1, reacted at 100 °C for 8 h and then filtered. The filtrate was adjusted to acidic with dilute hydrochloric acid, and the precipitated solid was filtered, washed with water and dried to obtain compound 3; 0.1 mol of compound 3, 5 mmol of pyridine and 0.3 mol of thionyl chloride were dissolved in 200 mL of tetrahydrofuran and reacted at room temperature for 3 h. After the solvent was removed by distillation under reduced pressure, compound 1 (m = 50) was obtained;
[0038] 0.2 mol of diphenyl ether, 0.7 mol of anhydrous aluminum trichloride and 800 g of dichloroethane were mixed in a reaction kettle. The system was cooled to -20 °C and bubbled with nitrogen for 1 h to obtain solution A; 0.16 mol of terephthaloyl chloride and 0.04 mol of compound 1 (m = 50) were dissolved in 400 g of dichloroethane to obtain solution B; solution B was slowly added dropwise to solution A under nitrogen protection and added dropwise within 2 h. The low-temperature reaction was maintained for 12 h, and then the temperature was raised to room temperature and the reaction continued for 12 h; the organic solvent was removed by filtration, and the obtained solid was washed 4 times with a mixed solution of 10% (volume fraction) HCl aqueous solution and ethanol in a volume ratio of 1:0.3, and then washed with water 2 times. After drying, PEKK polymer 2 (m = 50, the molar ratio of terephthaloyl chloride to compound 1 was 8:2) was obtained.
[0039] Synthesis Example 3
[0040] 0.1 mol of 3,5-dimethylphenol and 0.01 mol of sodium tert-butoxide were placed in a high-pressure reactor. 5 mol of ethylene oxide was introduced at 140 °C and reacted for 3 hours to obtain Compound 2. 0.1 mol of Compound 2 and 0.4 mol of potassium permanganate were dissolved in 200 mL of a mixed solution of pyridine and water with a volume ratio of 1:1. After reacting at 110 °C for 10 hours, it was filtered. The filtrate was adjusted to acidic with dilute hydrochloric acid. The precipitated solid was filtered, washed with water, and dried to obtain Compound 3. 0.1 mol of Compound 3, 10 mmol of pyridine, and 0.4 mol of thionyl chloride were dissolved in 200 mL of tetrahydrofuran and reacted at room temperature for 4 hours. After removing the solvent by vacuum distillation, Compound 1 (m = 50) was obtained;
[0041] 0.2 mol of diphenyl ether, 0.8 mol of anhydrous aluminum trichloride, and 800 g of chloroform were mixed in a reaction kettle. The system was cooled to -20 °C and bubbled with argon for 1 h to obtain Solution A. 0.14 mol of terephthaloyl chloride and 0.06 mol of Compound 1 (m = 50) were dissolved in 400 g of chloroform to obtain Solution B. Solution B was slowly added dropwise to Solution A under argon protection and was added dropwise within 2 h. The low temperature reaction was maintained for 12 h and then raised to room temperature and continued to react for 12 h. The organic solvent was removed by filtration. The obtained solid was washed 4 times with a mixed solution of 15% HCl aqueous solution and ethanol with a volume ratio of 1:0.4, and then washed 2 times with water and dried to obtain PEKK polymer 3 (m = 50, the molar ratio of terephthaloyl chloride to Compound 1 is 7:3).
[0042] Synthesis Example 4
[0043] 0.1 mol of 3,5-dimethylphenol and 0.01 mol of sodium tert-butoxide were placed in a high-pressure reactor. 10 mol of ethylene oxide was introduced at 140 °C and reacted for 3 hours to obtain Compound 2. 0.1 mol of Compound 2 and 0.4 mol of potassium permanganate were dissolved in 200 mL of a mixed solution of pyridine and water with a volume ratio of 1:1. After reacting at 110 °C for 10 hours, it was filtered. The filtrate was adjusted to acidic with dilute hydrochloric acid. The precipitated solid was filtered, washed with water, and dried to obtain Compound 3. 0.1 mol of Compound 3, 10 mmol of pyridine, and 0.4 mol of thionyl chloride were dissolved in 200 mL of tetrahydrofuran and reacted at room temperature for 4 hours. After removing the solvent by vacuum distillation, Compound 1 (m = 100) was obtained;
[0044] 0.2 mol of diphenyl ether, 0.9 mol of anhydrous aluminum trichloride and 800 g of o-dichlorobenzene were mixed in a reaction kettle. The temperature of the system was lowered to -30 °C, and argon was bubbled through for 1.5 h to obtain solution A. 0.12 mol of terephthaloyl chloride and 0.08 mol of compound 1 (m = 100) were dissolved in 400 g of o-dichlorobenzene to obtain solution B. Solution B was slowly added dropwise to solution A under argon protection, and the addition was completed in 3 h. The low-temperature reaction was maintained for 16 h, and then the temperature was raised to room temperature and the reaction was continued for 16 h. The organic solvent was removed by filtration, and the obtained solid was washed 5 times with a mixed solution of 20% hydrochloric acid aqueous solution and ethanol in a volume ratio of 1:0.5, and then washed 3 times with water. After drying, the PEKK polymer 4 (m = 100, the molar ratio of terephthaloyl chloride to compound 1 is 6:4) was obtained.
[0045] Comparative Example 1
[0046] Compound 1 in Synthesis Example 4 was replaced with isophthaloyl chloride, and the remaining steps were the same as those in Synthesis Example 4 to obtain Comparative PEKK Polymer 1 (the molar ratio of terephthaloyl chloride to isophthaloyl chloride is 6:4).
[0047] Comparative Example 2
[0048] Commercially available traditional PEKK polymer powder was used as Comparative Polymer 2 (the molar ratio of terephthaloyl chloride to isophthaloyl chloride is 6:4).
[0049] Application Example 1
[0050] The glass transition temperature (Tg) and melting temperature (Tm) of the PEKK polymer were measured by a differential scanning calorimeter (DSC). Testing of the mechanical properties of the polymer: The polymer powder was pressed into a thin sheet by a flat hot press. The die temperature of the flat hot press was set at 400 °C, and the tensile properties and flexural properties of the material were tested in accordance with the national standards GB / T 1040-2018 Determination of Tensile Properties of Plastics and GB / T 9341-2008 Determination of Flexural Properties of Plastics, respectively.
[0051] The test results are shown in Table 1 below:
[0052] Table 1 Comparison of the properties of different PEKK polymers
[0053] ,
[0054] It can be seen from this that: compared with traditional PEKK polymer molecules with a pure rigid structure (Comparative PEKK Polymer 1 and Comparative PEKK Polymer 2), the polymers prepared in the present invention (PEKK Polymer 1 to PEKK Polymer 4) introduce flexible polyether side chains into the rigid polymer main chain. Therefore, the polymers show lower glass transition temperatures and melting temperatures. The polymers prepared in the present invention show relatively slightly lower tensile strength, tensile modulus, flexural strength and flexural modulus, while showing significantly higher elongation at break than the comparative samples, indicating that they have better flexibility. Moreover, the more flexible polyether side chains the polymer molecules carry and the longer the polyether side chains, the greater the elongation at break and the better the flexibility. In summary, the PEKK polymers prepared in the present invention exhibit better flexibility, achieving a harmonious unity of strength, rigidity and flexibility.
[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A preparation method of a high-toughness polyether ketone ketone polymer, characterized in that, The specific process is as follows: S1. Mix diphenyl ether, anhydrous aluminum trichloride and an organic solvent in a reaction kettle, cool the reaction system to -10~-30 °C, and bubble with an inert gas for 0.5~1.5 h to obtain solution A; S2. Dissolve the mixture of terephthaloyl chloride and compound 1 in an organic solvent to obtain solution B; S3. Slowly drop solution B into solution A under the protection of an inert gas, complete the dropping in 1~3 h, maintain the low temperature of -10~-30 °C and react for 8~16 h, then raise the temperature to room temperature and continue to react for 8~16 h; S4. Filter to remove the organic solvent, wash the obtained solid 3~5 times with a mixed solution of HCl aqueous solution and ethanol, and then wash it 1~3 times with water. After drying, a PEKK polymer is obtained; the volume percentage concentration of the HCl aqueous solution is 5~20%, and the volume ratio of the HCl aqueous solution to ethanol is 1:0.2~0.5; The high-toughness polyether ketone ketone polymer is obtained by reacting diphenyl ether, terephthaloyl chloride, compound 1 and anhydrous aluminum trichloride with a molar ratio of 1:a:(1-a):(3~5), where the value of a is 0.5~0.9, and the compound 1 is isophthaloyl chloride with a flexible polyether side chain; The structural general formula of the compound 1 is as follows: ， Among them, m is an integer from 10 to 100.
2. The preparation method according to claim 1, characterized in that: The organic solvent is any one of dichloromethane, dichloroethane, chloroform, and o-dichlorobenzene.
3. The preparation method according to claim 1, characterized in that: The inert gas is nitrogen or argon.