Hyperbranched polyaryletherketone resin as well as preparation method and application thereof

Abstract

The invention discloses hyperbranched polyaryletherketone resin as well as a preparation method and application thereof, and the hyperbranched polyaryletherketone resin is obtained by carrying out polymerization reaction on a 4-fluorophenoxy phenol structural unit, 1, 3, 5-tri (4-fluorophenoxy) benzene and tetrafluoro terephthaloyl chloride under the action of a catalyst triethylamine. The hyperbranched polyaryletherketone resin is used as a toughening agent to be applied to modification of an epoxy material, a nanoscale dispersed phase can be formed in an epoxy network, and the glass-transition temperature is maintained at a relatively high level while the impact strength is improved by 200% through a rigid particle toughening mechanism; therefore, the problems that an existing epoxy material hyperbranched polymer modification system is too low in glass transition temperature, cannot meet the requirements of high-temperature working conditions and is poor in impact mechanical property are solved.

Description

Technical Field

[0001] The present invention relates to a novel hyperbranched polyaryletherketone resin, a preparation method thereof, and an application thereof, belonging to the technical field of polymer materials. Background Art

[0002] Epoxy composites play an important role in fields such as high-voltage electrical equipment and rail transit insulation components due to their high strength, high modulus, and excellent dimensional stability. However, during the curing process of epoxy resins, the formation of a high cross-linking density structure will cause a significant volume shrinkage effect, resulting in a curing stress of up to 50 - 100 MPa inside the material. This stress concentration will not only induce microcrack defects, causing local peeling failure of the epoxy insulation layer in porcelain insulator detection equipment, but also reduce the fatigue resistance of the material in a high-temperature arc environment, seriously threatening the long-term reliability of the equipment.

[0003] To alleviate the curing stress problem inside the epoxy insulation layer material of porcelain insulator detection equipment, the existing technologies mainly adopt three types of strategies: flexible chain segment modification (such as introducing polyurethane prepolymer), physical toughening agent dispersion (such as core-shell rubber particles), and topological structure regulation (such as hyperbranched polymers). Among them, hyperbranched polymers exhibit a unique stress buffering effect due to their three-dimensional branched structure and abundant terminal active sites. However, there are still some key defects in the existing hyperbranched modification systems, such as: the glass transition temperature is too low to meet the requirements of high-temperature working conditions; the difference in solubility parameters between hyperbranched polymers and epoxy matrices is likely to cause phase separation, restricting the mechanical properties of epoxy composites. Summary of the Invention

[0004] The main purpose of the present invention is to propose a hyperbranched polyaryletherketone resin, a preparation method thereof, and an application thereof, so as to solve the problems that the glass transition temperature of the hyperbranched polymer modification system of epoxy materials is too low to meet the requirements of high-temperature working conditions and the impact resistance mechanical properties are poor.

[0005] To achieve the above object, on the one hand, the present invention proposes a hyperbranched polyaryletherketone resin, which is obtained by a polymerization reaction of 4-fluorophenoxyphenol structural units, 1,3,5-tris(4-fluorophenoxy)benzene, and tetrafluoroterephthaloyl chloride.

[0006] Further, the 4-fluorophenoxyphenol structural unit is prepared by reacting 4-fluorophenol, bisphenol AF, and ammonium acetate in glacial acetic acid, and it has a fluorine-containing group and a phenoxy structure, which can provide low polarity characteristics and good stress dissipation ability for the polymer.

[0007] Further, the polymerization reaction is carried out under the catalytic action of a catalyst triethylamine.

[0008] Further, the amount of the catalyst triethylamine is 1.1 to 1.3 times the total amount of the 4-fluorophenoxyphenol structural unit, 1,3,5-tris(4-fluorophenoxy)benzene, and tetrafluoroterephthaloyl chloride.

[0009] Further, the molar ratio of the 4-fluorophenoxyphenol structural unit, 1,3,5-tris(4-fluorophenoxy)benzene, and tetrafluoroterephthaloyl chloride is (1.0 to 1.2):1:(1.5 to 1.8).

[0010] Further, the hyperbranched polyaryletherketone resin has the following structural characteristics: Repeating unit molecular formula: C 13 H4F4O2, repeating unit molecular weight: 268 g / mol; degree of polymerization: 7 to 67 repeating units; Main chain structure: composed of aryl ether ketone repeating units Ar-O-Ar-CO-, where Ar is a tetrafluorobenzene ring derived from tetrafluoroterephthaloyl chloride; the ether bond and the ketone bond are alternately connected to form a rigid backbone; the branching points are provided by 1,3,5-tris(4-fluorophenoxy)benzene: three sites of the central benzene ring are respectively connected to fluorophenoxy -O-C6H4-F, and each fluorophenoxy is connected to the aryl ether ketone chain segment to form a three-dimensional network; the unreacted 4-fluorophenol residues cap the polymer chain, and the ends are -O-C6H4-F or -C(CF3)3- structures.

[0011] Further, the hyperbranched polyaryletherketone resin has the following structural formula: .

[0012] To achieve the foregoing object, on the other hand, the present invention provides a method for preparing a hyperbranched polyaryletherketone resin, comprising the following steps: 1) preparing the 4-fluorophenoxyphenol structural unit with 4-fluorophenol, bisphenol AF, ammonium acetate, and glacial acetic acid; 2) preparing the 4-fluorophenoxyphenol structural unit, 1,3,5-tris(4-fluorophenoxy)benzene, and tetrafluoroterephthaloyl chloride in proportion, and subjecting the three to a polymerization reaction under the action of the catalyst triethylamine to generate a hyperbranched polyaryletherketone resin modified with fluorine-containing end groups.

[0013] Further, in step 2), the molar ratio of the 4-fluorophenoxyphenol structural unit, 1,3,5-tris(4-fluorophenoxy)benzene, and tetrafluoroterephthaloyl chloride is (1.0 to 1.2):1:(1.5 to 1.8).

[0014] To achieve the foregoing object, the present invention also provides an application of the foregoing hyperbranched polyaryletherketone resin as a toughening agent in the preparation of epoxy composites.

[0015] The beneficial effects of the technical solution of the present invention are reflected in that: the hyperbranched polyaryletherketone resin of the present invention is obtained by the polymerization reaction of 4-fluorophenoxyphenol structural units, 1,3,5-tris(4-fluorophenoxy)benzene and tetrafluoroterephthaloyl chloride. Among them, the 4-fluorophenoxyphenol structural unit has a fluorine-containing group and a phenoxy structure, which can provide the polymer with low polarity characteristics and good stress dissipation ability; 1,3,5-tris(4-fluorophenoxy)benzene has three-dimensional branching potential. As the core structural unit of the hyperbranched polyaryletherketone resin, it can promote the formation of abundant branching points during the growth of the polymer chain, thereby increasing the free volume of the molecular chain; tetrafluoroterephthaloyl chloride has two reactive sites, which can effectively promote the formation of the hyperbranched structure and introduce fluorine elements at the polymer end groups, endowing the material with low polarity and excellent dielectric properties. The hyperbranched polyaryletherketone resin modified with fluorine-containing end groups obtained by the polymerization reaction of 4-fluorophenoxyphenol structural units, 1,3,5-tris(4-fluorophenoxy)benzene and tetrafluoroterephthaloyl chloride, on the one hand, the benzene ring structure in its molecular chain can provide higher thermal stability, and the free volume holes generated by the hyperbranched topology can effectively dissipate the curing stress. At the same time, it can form a nano-scale dispersed phase in the epoxy network, and through the "rigid particle toughening" mechanism, the impact strength is increased by 200% while maintaining the glass transition temperature at a relatively high level.

[0016] When the hyperbranched polyaryletherketone resin of the present invention is used as a toughening agent for the modification of epoxy materials, the rigid molecular skeleton formed by the benzene ring and ether ketone bonds of the hyperbranched polyaryletherketone resin modified with fluorine-containing end groups significantly inhibits the relaxation of the molecular chain at high temperatures; its hyperbranched structure increases the free volume of the molecular chain, hinders the slippage of the molecular chain, forms a hyperbranched topological lock, and effectively restricts the movement of the epoxy chain segments, thereby significantly increasing the glass transition temperature of the epoxy composite material. In terms of mechanical properties, the addition of the hyperbranched polyaryletherketone resin modified with fluorine-containing end groups significantly improves the impact strength and tensile strength of the epoxy composite material. Its hyperbranched structure absorbs energy through cavity deformation during the impact process, and at the same time, the fluorine-containing groups at its ends form covalent bonds with the epoxy groups, enhancing the interfacial stress transfer efficiency. Specific embodiments

[0017] The present invention will be further described below in conjunction with specific embodiments and examples.

[0018] An embodiment of the present invention provides a novel hyperbranched polyaryletherketone resin, which is obtained by a polymerization reaction of three specific monomers, namely, a 4-fluorophenoxyphenol structural unit, 1,3,5-tris(4-fluorophenoxy)benzene, and tetrafluoroterephthaloyl chloride with unique reactivity, under the action of a catalyst triethylamine. The unique reactivity of the tetrafluoroterephthaloyl chloride is reflected in that the molecular structure of tetrafluoroterephthaloyl chloride contains two acyl chloride groups (-COCl), and these two acyl chloride groups are reactive sites. At the same time, the fluorine atoms contained therein have strong electronegativity and can affect the electron distribution of the acyl chloride groups through the inductive effect. The fluorine atoms have the characteristic of low polarity, which can reduce the surface energy of the polymer, improve its hydrophobicity and dielectric properties, and also help to improve the thermal stability and chemical stability of the polymer.

[0019] In some specific embodiments, the 4-fluorophenoxyphenol structural unit can be prepared by reacting 4-fluorophenol, bisphenol AF, and ammonium acetate in glacial acetic acid. It has a fluorine-containing group and a phenoxy structure, which can provide the polymer with low polarity characteristics and good stress dissipation ability. Among them, the molecular formula of 4-fluorophenol is C6H5FO, the molecular weight is 112.10 g / mol, and the structural formula is ; the molecular formula of bisphenol AF is C 15 H 10 F6O2, the molecular weight is 336.23 g / mol, and the structural formula is: .

[0020] 1,3,5-Tris(4-fluorophenoxy)benzene in the embodiment of the present invention has three-dimensional branching potential. As the core structural unit of the hyperbranched polyaryletherketone resin, it can promote the formation of abundant branching points during the growth of the polymer chain, thereby increasing the free volume of the molecular chain. In the embodiment of the present invention, the molecular formula of 1,3,5-tris(4-fluorophenoxy)benzene is C 24 H 15 F3O3, the molecular weight is 408.39 g / mol, and the structural formula is: .

[0021] Tetrafluoroterephthaloyl chloride in the embodiment of the present invention has two reactive sites, which can effectively promote the formation of a hyperbranched structure and introduce fluorine elements at the polymer end groups, endowing the material with low polarity and excellent dielectric properties. The tetrafluoroterephthaloyl chloride used in the specific embodiments of the present invention can be purchased from a conventional chemical reagent supplier. Its molecular formula is C8Cl2F4O2, the molecular weight is 274.98 g / mol, and the structural formula is: .

[0022] In an embodiment of the present invention, triethylamine is used as a catalyst, which can effectively promote the nucleophilic substitution reaction, enabling the monomers to fully polymerize. When the amount of the catalyst is about 1.2 times the total molar amount of the monomers, the reaction can proceed smoothly to obtain a hyperbranched poly(aryl ether ketone) resin modified with fluorinated end groups and having a high degree of branching. The present invention places no special limitation on the source of the triethylamine, and conventional commercially available products can be used. In some other embodiments, organic bases such as triethanolamine and pyridine can also be used to replace triethylamine as the catalyst. However, triethylamine is preferably used in the embodiments of the present invention because triethylamine has a high catalytic efficiency and can effectively accelerate the reaction rate; at the same time, it has good compatibility.

[0023] In some specific embodiments of the present invention, the molar ratio of the 4-fluorophenoxyphenol structural unit, 1,3,5-tris(4-fluorophenoxy)benzene to terephthaloyl chloride tetrafluoride is preferably (1.0 - 1.2):1:(1.5 - 1.8). By controlling the molar ratio of the 4-fluorophenoxyphenol structural unit, 1,3,5-tris(4-fluorophenoxy)benzene to terephthaloyl chloride tetrafluoride within the above range, the monomers can fully react, thereby obtaining a hyperbranched poly(aryl ether ketone) resin modified with fluorinated end groups and having excellent solubility, thermal stability and toughening effect. As a toughening agent for epoxy resin, this resin can significantly improve the mechanical properties, thermal stability and dielectric properties of epoxy resin, meeting the use requirements of porcelain insulator zero detection equipment under harsh environments such as high temperature and high voltage stress.

[0024] The hyperbranched poly(aryl ether ketone) resin of the embodiment of the present invention has the following structural characteristics: Repeating unit molecular formula: C 13 H4F4O2, repeating unit molecular weight: 268 g / mol; degree of polymerization (about 7 - 67 repeating units); main chain structure: composed of aryl ether ketone repeating units Ar - O - Ar - CO -, where: Ar is a tetrafluorobenzene ring (from terephthaloyl chloride tetrafluoride). Ether bonds and ketone bonds are alternately connected to form a rigid backbone. The branching points are provided by 1,3,5-tris(4-fluorophenoxy)benzene: three sites of the central benzene ring are respectively connected to fluorophenoxy groups (-O - C6H4 - F). Each fluorophenoxy group is further connected to the aryl ether ketone chain segment to form a three-dimensional network. The unreacted 4-fluorophenol residues cap the polymer chains, and the ends have the structure of -O - C6H4 - F or -C(CF3)3 -.

[0025] The hyperbranched poly(aryl ether ketone) resin of the embodiment of the present invention has the following structural formula: .

[0026] Another embodiment of the present invention provides a method for preparing the aforementioned hyperbranched poly(aryl ether ketone) resin, which specifically includes the following steps: 1) Place 4-fluorophenol (1.5 g), bisphenol AF (1.5 g), 1,3,5-tris(4-fluorophenoxy)benzene (1.5 g), tetrafluoroterephthaloyl chloride (3 g), triethylamine (2 g) and sodium fluoride (0.3 g) in a vacuum drying oven and dry at 90 °C for 24 hours to ensure the dryness and purity of the raw materials; 2) Sequentially add 4-fluorophenol (C6H5FO), bisphenol AF (C 15 H 10 F6O2), 15 g of ammonium acetate (NH4OAc) and 100 mL of glacial acetic acid (CH3COOH) into a 500 mL three-necked flask. Under a nitrogen atmosphere, gradually heat the reaction mixture to 110 °C and reflux and stir at this temperature for 10 hours; the reaction formula is: 2C6H5F-OH + HO-C6H4-C(CF3)2-C6H4-OH → [F-C6H4-O-C6H4-C(CF3)2-C6H4-O-C6H4-F] + 2H2O.

[0027] 3) After the reaction is completed, cool the reaction mixture to room temperature and slowly add it to hot deionized water to obtain a white powder precipitate; then filter the precipitate with a Buchner funnel, wash it with deionized water to remove the residual acetic acid, and dry it to obtain a pale yellow solid, which is the synthesized monomer 4-fluorophenoxyphenol structural unit; 4) Sequentially add the above-synthesized monomer 4-fluorophenoxyphenol structural unit, 1,3,5-tris(4-fluorophenoxy)benzene, tetrafluoroterephthaloyl chloride, triethylamine, and the organic reaction solvent tetrahydrofuran (150 mL) into a 500 mL three-necked flask. Under a nitrogen atmosphere, gradually heat the mixture to 50 °C to promote the reaction and reflux for 6 hours; among them, the 4-fluorophenoxyphenol structural unit is an A2-type monomer containing 2 phenolic hydroxyl groups; 1,3,5-tris(4-fluorophenoxy)benzene is a B3-type monomer containing 3 fluorophenoxy groups; tetrafluoroterephthaloyl chloride is a C2-type monomer containing 2 acyl chloride groups; triethylamine (Et3N) is used as a catalyst, and the reaction formula is as follows: n A2 + m B3 + p C2 → hyperbranched polyaryletherketone resin.

[0028] 5) Cool the reaction mixture to room temperature and slowly pour it into a large amount of water to precipitate the polymer; then wash the precipitate 3 times with ethanol to remove the unreacted monomers and small molecule impurities (the unreacted monomers and small molecule impurities adhere to the precipitated polymer with small water droplets, so ethanol washing is required); finally, dry the washed polymer in a vacuum drying oven at 60 °C to constant weight to obtain the fluorine-terminated modified hyperbranched polyaryletherketone resin.

[0029] Another embodiment of the present invention further discloses the application of the aforementioned hyperbranched polyaryletherketone resin as a toughening agent in the preparation of epoxy composites. In some specific embodiments, an epoxy composite material, the raw materials of which include the following components in parts by mass: 70-90 parts of epoxy resin, 15-25 parts of the fluorine-terminated modified hyperbranched polyaryletherketone resin obtained in the aforementioned embodiments, 70-90 parts of curing agent, and 2-8 parts of accelerator. Among them, the epoxy resin includes one or more of bisphenol A epoxy resin and bisphenol F epoxy resin; the curing agent is one or more of cyclohexanedimethanamine and isophorone diamine; the accelerator is one or more of N,N-dimethylethanolamine, benzyltrimethylammonium chloride, and N-methylpyrrolidone (NMP).

[0030] The preparation method of the above epoxy composite material includes the following steps: 1) Place the epoxy resin, the fluorine-terminated modified hyperbranched polyaryletherketone resin, and the accelerator in an oven for drying, the drying temperature is 70-90 °C, and the drying time is 3-4 h; 2) Heat and stir the epoxy resin and the fluorine-terminated modified hyperbranched polyaryletherketone resin for blending to obtain an epoxy prepreg. Among them, the heating temperature is 120-140 °C, the stirring rate is 200-300 r / min, and the stirring time is 20-40 min; 3) Add the accelerator and the curing agent to the epoxy prepreg, and stir under vacuum heating. Among them, the reaction environment is vacuum-treated, the heating temperature is 120-140 °C, the stirring rate is 200-300 r / min, and the stirring time is 20-40 min; 4) Pour the epoxy prepreg into a specified mold and cure to obtain an epoxy composite sample. Among them, the curing is divided into pre-curing and post-curing. The pre-curing time is 3-5 h, and the curing temperature is 90-110 °C; the post-curing time is 10-14 h, and the post-curing temperature is 140-160 °C; 5) Demold after curing to obtain an epoxy composite sample.

[0031] Implementing the embodiments of the present invention will have the following beneficial effects: By compounding the fluorine-terminated modified hyperbranched polyaryletherketone resin with the epoxy resin, the embodiments of the present invention construct an epoxy composite material system with both excellent heat resistance and mechanical properties, which can meet the performance requirements of porcelain insulator zero detection equipment in harsh environments such as high temperature and high voltage. Among them, the fluorine-terminated modified hyperbranched polyaryletherketone resin forms a three-dimensional interpenetrating network through chemical bonding with epoxy groups through its unique hyperbranched topological structure; at the same time, its fluorine-terminated groups provide low polarity characteristics, significantly improving the dielectric properties of the material. Through this method, the performance of the epoxy composite material is accurately regulated, effectively improving the heat resistance and mechanical properties of the epoxy composite material.

[0032] The rigid molecular skeleton formed by the benzene rings and ether-ketone bonds of the fluorine-terminated modified hyperbranched poly(aryl ether ketone) resin significantly inhibits the relaxation of molecular chains at high temperatures. Its hyperbranched structure increases the free volume of the molecular chains, hinders the slippage of the molecular chains, forms a hyperbranched topological lock, effectively restricts the movement of the epoxy segments, and thus significantly increases the glass transition temperature of the epoxy composite material.

[0033] In terms of mechanical properties, the addition of the fluorine-terminated modified hyperbranched poly(aryl ether ketone) resin significantly improves the impact strength and tensile strength of the epoxy composite material. Its hyperbranched structure absorbs energy through cavitation deformation during the impact process. At the same time, the fluorine-containing groups at its ends form covalent bonds with the epoxy groups, enhancing the interfacial stress transfer efficiency.

[0034] The procurement sources of the reagents in the examples and comparative examples of the present invention are shown in Table 1: Table 1 Process properties of epoxy composite materials

[0035] The following are specific examples and comparative examples: The following Table 2 shows the material formulations of the epoxy composites in the specific examples and comparative examples, and Table 2 clarifies the components of each material in different examples and comparative examples.

[0036] Table 2 Material formulation of epoxy composites

[0037] The preparation method of the epoxy composite materials in the above examples and comparative examples includes the following steps: 1) Place the epoxy resin, the fluorine-terminated modified hyperbranched poly(aryl ether ketone) resin, and the accelerator in an oven for drying. The drying temperature is 90 °C, and the drying time is 3 h; 2) Heat and stir the epoxy resin and the fluorine-terminated modified hyperbranched poly(aryl ether ketone) resin for blending to obtain an epoxy resin prepreg. Among them, the heating temperature is 130 °C, the stirring rate is 250 r / min, and the stirring time is 40 min; 3) Add the accelerator and the curing agent to the epoxy resin prepreg, and stir under vacuum heating. Among them, the reaction environment is subjected to vacuum treatment, the heating temperature is 130 °C, the stirring rate is 300 r / min, and the stirring time is 25 min; 4) Pour the epoxy resin prepreg into a specified mold and cure to obtain an epoxy resin composite sample. Among them, the curing is divided into pre-curing and post-curing. The pre-curing time is 4 h, and the curing temperature is 100 °C; the post-curing time is 13 h, and the post-curing temperature is 150 °C; 5) Demold after curing to obtain an epoxy composite sample.

[0038] Test examples: The mechanical properties and thermal properties of the above Examples 1 - 3 and Comparative Examples 1 - 3 were tested, and the standards for each test are as follows: Flexural strength: Test method for flexural properties of resin castings, GB / T 2570 - 1995; Impact strength: Test method for impact of resin castings, GB / T 2571—1995; Tensile shear strength: Determination of tensile shear strength of adhesives, GB / T 7124 - 2008; Glass transition temperature: Differential scanning calorimetry (DSC) for plastics - Part 2: Determination of glass transition temperature, GB / T 19466.2 - 2004.

[0039] The mechanical properties and heat resistance of Examples 1 - 3 and Comparative Examples 1 - 3 were tested, and their flexural strength, impact strength, tensile shear strength and glass transition temperature were tested. The test results are shown in Table 3.

[0040] Table 3 Mechanical properties of epoxy composites

[0041] It can be seen from the test results that the mechanical properties and heat resistance of Examples 1 - 3 are better than those of Comparative Examples 1 - 3. In Comparative Example 1, no toughening agent was used for modification, and the toughness of the epoxy composite was insufficient, resulting in a decrease in its flexural strength, impact strength and tensile shear strength due to the accumulation of internal stress. In Comparative Example 2, isophorone diamine was used for curing, resulting in a lower heat resistance of the material than that of Comparative Example 1. After comparison between the examples and the comparative examples, after adding hyperbranched polyaryletherketone resin for modification, the glass transition temperature of the material increased by more than 10 °C, and the heat resistance was significantly improved. When 20 parts of hyperbranched polyaryletherketone resin was added, the thermal performance was optimal. The experimental results show that the novel hyperbranched polyaryletherketone resin can also greatly improve the mechanical properties of the material. The impact strength of the modified epoxy composite increased by more than 100%, proving the stability and reliability of the composite material in a mechanical stress environment.

[0042] In summary, the present invention uses hyperbranched polyaryletherketone resin modified with fluorine - terminated groups as a toughening agent and composes it with epoxy resin, successfully constructing an epoxy composite material system with excellent heat resistance and mechanical properties. This material can meet the performance requirements of porcelain insulator zero - detection equipment in harsh environments such as high temperature and high voltage, providing technical support for the safe, reliable and long - term operation of the equipment.

[0043] The above content is a further detailed description of the present invention in combination with specific preferred embodiments. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several equivalent substitutions or obvious modifications can be made, and as long as the performance or use is the same, they should all be regarded as falling within the protection scope of the present invention.

Claims

1. A hyperbranched polyaryletherketone resin, characterized in that, It is obtained by the polymerization reaction of 4-fluorophenoxyphenol structural units, 1,3,5-tris(4-fluorophenoxy)benzene and tetrafluoroterephthaloyl chloride.

2. The hyperbranched polyaryletherketone resin according to claim 1, wherein The 4-fluorophenoxyphenol structural units are prepared by the reaction of 4-fluorophenol, bisphenol AF and ammonium acetate in glacial acetic acid. It has fluorine-containing groups and phenoxy structures, which can provide the polymer with low polarity characteristics and good stress dissipation ability.

3. The hyperbranched polyaryletherketone resin according to claim 1 or 2, characterized in that, The polymerization reaction is carried out under the catalysis of the catalyst triethylamine.

4. The hyperbranched polyaryletherketone resin according to claim 3, wherein The dosage of the catalyst triethylamine is 1.1 - 1.3 times the total amount of the 4-fluorophenoxyphenol structural units, 1,3,5-tris(4-fluorophenoxy)benzene and tetrafluoroterephthaloyl chloride.

5. The hyperbranched polyaryletherketone resin according to claim 1, wherein The molar ratio of the 4-fluorophenoxyphenol structural units, 1,3,5-tris(4-fluorophenoxy)benzene and tetrafluoroterephthaloyl chloride is (1.0 - 1.2):1:(1.5 - 1.8).

6. The hyperbranched polyaryletherketone resin according to claim 1, wherein It has the following structural characteristics: Repeating unit molecular formula: C 13 H4F4O2, repeating unit molecular weight: 268 g / mol; degree of polymerization 7 to 67 repeating units; Main chain structure: It is composed of aromatic ether ketone repeating units Ar-O-Ar-CO-, where Ar is a tetrafluorobenzene ring from tetrafluoroterephthaloyl chloride; the ether bond and the ketone bond are alternately connected to form a rigid skeleton; the branching point is provided by 1,3,5-tris(4-fluorophenoxy)benzene: three sites of the central benzene ring are respectively connected to fluorophenoxy -O-C6H4-F, and each fluorophenoxy is connected to the aromatic ether ketone chain segment to form a three-dimensional network; the unreacted 4-fluorophenol residues cap the polymer chain, and the end is -O-C6H4-F or -C(CF3)3- structure.

7. The hyperbranched polyaryletherketone resin according to claim 1 or 6, characterized in that, It has the following structural formula: 。 8. The preparation method of the hyperbranched polyaryletherketone resin according to any one of claims 1-7, characterized in that, It includes the following steps: 1) Prepare the 4-fluorophenoxyphenol structural units with 4-fluorophenol, bisphenol AF, ammonium acetate and glacial acetic acid; 2) Prepare the 4-fluorophenoxyphenol structural units, 1,3,5-tris(4-fluorophenoxy)benzene and tetrafluoroterephthaloyl chloride in proportion, and let the three react under the action of the catalyst triethylamine to generate a hyperbranched polyaryletherketone resin modified with fluorine-containing end groups.

9. The preparation method of the hyperbranched polyaryletherketone resin according to claim 8, characterized in that, In step 2), the molar ratio of the 4-fluorophenoxyphenol structural units, 1,3,5-tris(4-fluorophenoxy)benzene and tetrafluoroterephthaloyl chloride is (1.0 - 1.2):1:(1.5 - 1.8).

10. Application of the hyperbranched polyaryletherketone resin according to any one of claims 1 - 7 as a toughening agent in the preparation of epoxy composites.

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