High-strength polyetherketoneketone polymer and preparation method thereof

Abstract

The invention discloses a high-strength polyetherketoneketone polymer and a preparation method thereof, and belongs to the technical field of macromolecular special engineering plastics. The high-strength polyether ketone ketone polymer is obtained by reacting diaryl ether, paraphthaloyl chloride, isophthaloyl chloride and anhydrous aluminum trichloride in a molar ratio of 1: m: (1-m): (3-5), wherein m is 0-1. According to the high-strength PEKK polymer, two large condensed rings and one benzene ring form a minimum repetitive unit, and compared with a traditional PEKK polymer which forms a minimum repetitive unit by three benzene rings, a molecular main chain of the high-strength PEKK polymer has higher rigidity, and an engineering material prepared from the high-strength PEKK polymer also has higher mechanical strength and high temperature resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer special engineering plastics, and specifically relates to a high-strength polyetherketoneketone 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 composite materials have become one of the developing high-tech materials due to their light weight, high specific strength, high specific modulus, high temperature resistance and strong performance designability. Their application in industries such as aerospace has also shown unique advantages and potential. At present, common high-performance resin matrices can generally be divided into two categories: thermoplastic and thermosetting resins. Typical high-performance thermoplastic resins include thermoplastic polyimide, polyamide, polyether sulfone, 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 and the best comprehensive performance among special engineering plastics, with a long-term heat resistance of more than 250 ℃. In addition, PEAK also has excellent self-lubrication, flame retardancy and chemical resistance. PEAK's excellent comprehensive performance makes it widely used in the automotive industry, aerospace, electronic information, transportation pipelines and other fields.

[0003] PEAK can be divided into polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketoneketone (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. PEKK and its composite materials are polymers with 2 ketone bonds and 1 ether bond repeating units in the main chain structure, which are different from PEEK and surpass 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 resistance and chemical corrosion resistance, radiation resistance and flame retardancy, etc. These properties make it particularly suitable for use as a resin matrix and super engineering plastics for high-performance composite materials.

[0004] The PEKK preparation processes reported so far are mainly divided into two types: nucleophilic substitution and electrophilic substitution. Among them, the side reactions of nucleophilic substitution, such as branching and cross-linking, are easier to control, but the reaction conditions are harsh (usually required to be carried out at a temperature of >300 °C), and the synthesis process is complicated, the monomer is expensive, and the production cost is high, which restricts the wide application of this method. The conditions of electrophilic substitution are relatively mild and the raw materials are cheaper, but there are also disadvantages such as many side reactions, large catalyst dosage, and cumbersome post-treatment process. At present, the common electrophilic substitution polymerization process is mostly based on diphenyl ether and p- / isophthaloyl chloride as copolymer monomers, Lewis acid / base as catalyst, and condensation reaction at low temperature to room temperature (CN106800649B, CN109608627B, CN109608626B, CN109593183B and CN107973902B). Therefore, it is of great practical significance to develop new structural PEKK polymers with high performance and their preparation processes through molecular design. Summary of the invention

[0005] Technical problems to be solved: In response to the above technical problems, the present invention provides a high-strength polyetherketoneketone polymer and a preparation method thereof, which can effectively solve the shortcomings of complex nucleophilic substitution synthesis process, expensive monomers, high production cost, many electrophilic substitution side reactions, large catalyst dosage, and cumbersome post-treatment process.

[0006] Technical solution: In the first aspect, the present invention provides a high-strength polyetherketoneketone polymer, and the general structural formula of the high-strength polyetherketoneketone polymer is as follows: , wherein X is any one of naphthalene, anthracene, phenanthrene, pyrene and perylene, and n is an integer of 10 to 10,000.

[0007] In a second aspect, the present invention provides a method for preparing the high-strength polyetherketoneketone polymer described in the first aspect, wherein the high-strength polyetherketoneketone polymer is obtained by reacting diaryl ether, terephthaloyl chloride, isophthaloyl chloride and anhydrous aluminum chloride in a molar ratio of 1:m:(1-m):(3~5), wherein m is 0~1.

[0008] Preferably, the general structural formula of the diaryl ether is XOX, wherein X is any one of naphthalene, anthracene, phenanthrene, pyrene and perylene.

[0009] Preferably, the specific process of the preparation method is as follows: S1. Mix diaryl ether, anhydrous aluminum chloride and an organic solvent in a reaction kettle, cool the system to -10~-30 °C, and bubble with inert gas for 0.5~1.5 h to obtain solution A; S2, dissolving terephthaloyl chloride and isophthaloyl chloride in an organic solvent to obtain a solution B; S3. Under the protection of inert gas, slowly add solution B to solution A, and complete the addition within 1 to 3 hours. Maintain the reaction at -10 to -30 °C for 8 to 16 hours, then warm to room temperature and continue the reaction for 8 to 16 hours. S4. Filter and remove the organic solvent, wash the obtained solid with a mixture of HCl aqueous solution and ethanol for 3 to 5 times, then wash with water for 1 to 3 times, and obtain a PEKK polymer after drying; wherein the volume percentage concentration of the HCl aqueous solution is 5 to 20%, and the volume ratio of the HCl aqueous solution to the ethanol is 1:0.2 to 0.5.

[0010] Furthermore, the organic solvent is any one of dichloromethane, dichloroethane, chloroform, and o-dichlorobenzene.

[0011] Furthermore, the inert gas is nitrogen or argon.

[0012] Beneficial effects: The high-strength PEKK polymer of the present invention consists of two large condensed rings and one benzene ring as the minimum repeating unit. Compared with the traditional PEKK polymer consisting of three benzene rings as the minimum repeating unit, its molecular main chain has stronger rigidity, and the engineering material prepared therefrom also has higher mechanical strength and high temperature resistance. DETAILED DESCRIPTION

[0013] The present invention is described in detail below in conjunction with specific embodiments: All materials used were commercially available products, among which all chemical reagents (analytical grade) used for PEKK polymer synthesis were purchased from Anage Technology Co., Ltd., and organic solvents (analytical grade) were purchased from Sinopharm Chemical Reagent Co., Ltd.

[0014] Synthesis Example 1 0.2 mol of dinaphthyl ether, 0.6 mol of anhydrous aluminum chloride and 800 g of ethylene dichloride were mixed in a reactor, the system was cooled to -10 °C, and nitrogen was bubbled for 0.5 h to obtain solution A; 0.12 mol of terephthaloyl chloride and 0.08 mol of isophthaloyl chloride were dissolved in 400 g of ethylene dichloride to obtain solution B; solution B was slowly added dropwise to solution A under nitrogen protection for 1 h, the reaction was maintained at low temperature for 8 h, and then the reaction was continued at room temperature for 8 h; the organic solvent was filtered out, and the obtained solid was washed three times with a mixed solution of 5% by volume HCl aqueous solution and ethanol in a volume ratio of 1:0.2, and then washed once with water, and dried to obtain a high-strength PEKK polymer 1 (X is naphthyl, and the molar ratio of terephthaloyl chloride to isophthaloyl chloride is 6:4).

[0015] Synthesis Example 2 0.2 mol of dianthryl ether, 0.7 mol of anhydrous aluminum chloride and 800 g of ethylene dichloride were mixed in a reactor, the system was cooled to -20 °C, and nitrogen was bubbled for 1 h to obtain solution A; 0.14 mol of terephthaloyl chloride and 0.06 mol of isophthaloyl chloride were dissolved in 400 g of ethylene dichloride to obtain solution B; solution B was slowly added dropwise to solution A under nitrogen protection for 2 h, the reaction was maintained at low temperature for 12 h, and then the reaction was continued at room temperature for 12 h; the organic solvent was filtered out, and the obtained solid was washed 4 times with a mixed solution of 10% by volume HCl aqueous solution and ethanol in a volume ratio of 1:0.3, and then washed twice with water, and dried to obtain a high-strength PEKK polymer 2 (X is anthracene, and the molar ratio of terephthaloyl chloride to isophthaloyl chloride is 7:3).

[0016] Synthesis Example 3 0.2 mol of dipyrene ether, 0.8 mol of anhydrous aluminum chloride and 800 g of chloroform were mixed in a reactor, the system was cooled to -20 °C, and argon was bubbled for 1 h to obtain solution A; 0.14 mol of terephthaloyl chloride and 0.06 mol of isophthaloyl chloride were dissolved in 400 g of chloroform to obtain solution B; solution B was slowly added dropwise to solution A under argon protection for 2 h, the reaction was maintained at low temperature for 12 h, and then the reaction was continued at room temperature for 12 h; the organic solvent was filtered out, and the obtained solid was washed 4 times with a mixed solution of 15% by volume HCl aqueous solution and ethanol in a volume ratio of 1:0.4, and then washed twice with water, and dried to obtain a high-strength PEKK polymer 3 (X is pyrene, and the molar ratio of terephthaloyl chloride to isophthaloyl chloride is 7:3).

[0017] Synthesis Example 4 0.2 mol of perylene ether, 0.9 mol of anhydrous aluminum chloride and 800 g of o-dichlorobenzene were mixed in a reactor, the system was cooled to -30 °C, and argon was bubbled for 1.5 h to obtain solution A; 0.16 mol of terephthaloyl chloride and 0.04 mol of isophthaloyl chloride were dissolved in 400 g of o-dichlorobenzene to obtain solution B; solution B was slowly added dropwise to solution A under argon protection for 3 h, the reaction was maintained at low temperature for 16 h, and then the reaction was continued at room temperature for 16 h; the organic solvent was filtered out, and the obtained solid was washed 5 times with a mixed solution of 20% by volume HCl aqueous solution and ethanol in a volume ratio of 1:0.5, and then washed 3 times with water, and dried to obtain a high-strength PEKK polymer 4 (X is perylene, and the molar ratio of terephthaloyl chloride to isophthaloyl chloride is 8:2).

[0018] Comparative Example 1 The dinaphthyl ether in Synthesis Example 1 was replaced by diphenyl ether, and the remaining steps were the same as those in Synthesis Example 1 to obtain Comparative Polymer 1 (X was phenyl, and the molar ratio of terephthaloyl chloride to isophthaloyl chloride was 6:4).

[0019] Comparative Example 2 Commercially available conventional PEKK polymer powder was used as comparative polymer 2 (X is phenyl, and the molar ratio of terephthaloyl chloride to isophthaloyl chloride is 6:4).

[0020] Application Example 1 The glass transition temperature (T g ) and melting temperature (T m ) is obtained by differential scanning calorimetry (DSC). Test of polymer mechanical properties: The polymer powder is pressed into thin sheets by a flat hot press, and the mold temperature of the flat hot press is set to 400 °C. The tensile properties and bending properties of the material are tested in accordance with the national standards GB / T 1040-2018 "Determination of tensile properties of plastics" and GB / T 9341-2008 "Determination of bending properties of plastics".

[0021] The test results are shown in Table 1 below: Table 1 Performance test results of different PEKK polymers , It can be seen from Table 1 that compared with the traditional PEKK polymer (Comparative Polymer 1 and Comparative Polymer 2) whose minimum repeating unit is composed of three benzene rings, the polymers prepared by the present invention (high-strength PEKK polymer 1~high-strength PEKK polymer 4) are composed of two large condensed rings and one benzene ring as the minimum repeating unit, and their molecular main chains have stronger rigidity. Therefore, the polymers of the present invention show higher glass transition temperature and melting temperature, indicating that they have better high temperature resistance; at the same time, the polymers show higher tensile strength, tensile modulus, bending strength, and bending modulus, indicating that the polymers of the present invention have better mechanical strength; and the larger the condensed ring unit X of the polymer of the present invention (the more benzene rings the X group carries), the larger the corresponding value. In summary, the PEKK polymer prepared by the present invention has better mechanical strength and high temperature resistance.

[0022] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-strength polyetherketoneketone polymer, characterized in that: The general structural formula of the high-strength polyetherketoneketone polymer is as follows: , wherein X is any one of naphthalene, anthracene, phenanthrene, pyrene and perylene, and n is an integer of 10 to 10,000.

2. A method for preparing the high-strength polyetherketoneketone polymer according to claim 1, characterized in that: The high-strength polyetherketoneketone polymer is obtained by reacting diaryl ether, terephthaloyl chloride, isophthaloyl chloride and anhydrous aluminum chloride in a molar ratio of 1:m:(1-m):(3-5), wherein m is 0-1.

3. The preparation method according to claim 2, characterized in that: The general structural formula of the diaryl ether is XOX, wherein X is any one of naphthalene, anthracene, phenanthrene, pyrene and perylene.

4. The preparation method according to claim 2, characterized in that: The specific process is as follows: S1. Mix diaryl ether, anhydrous aluminum chloride and an organic solvent in a reaction kettle, cool the system to -10~-30°C, and bubble with inert gas for 0.5~1.5 h to obtain solution A; S2, dissolving terephthaloyl chloride and isophthaloyl chloride in an organic solvent to obtain a solution B; S3. Under the protection of inert gas, slowly add solution B to solution A, and complete the addition within 1 to 3 hours. Maintain the reaction at -10 to -30 °C for 8 to 16 hours, then warm to room temperature and continue the reaction for 8 to 16 hours. S4. Filter and remove the organic solvent, wash the obtained solid with a mixture of HCl aqueous solution and ethanol for 3 to 5 times, then wash with water for 1 to 3 times, and obtain a PEKK polymer after drying; wherein the volume percentage concentration of the HCl aqueous solution is 5 to 20%, and the volume ratio of the HCl aqueous solution to the ethanol is 1:0.2 to 0.

5.

5. The preparation method according to claim 4, characterized in that: The organic solvent is any one of dichloromethane, dichloroethane, chloroform and o-dichlorobenzene.

6. The preparation method according to claim 4, characterized in that: The inert gas is nitrogen or argon.

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