Dendritic polyether ketone ketone polymer and preparation method thereof

Abstract

The invention relates to a dendritic polyether ketone ketone polymer and a preparation method thereof, and belongs to the technical field of organic chemistry. In order to solve the problem of difficult toughening of high-temperature cured epoxy resin, the invention provides a preparation method of a dendritic polyetherketoneketone polymer, which comprises the following steps: preparing paraphthaloyl chloride, preparing an ether ketone ketone ether monomer and synthesizing the dendritic polyetherketoneketone polymer. The preparation method of the dendritic polyetherketoneketone polymer is low in cost, mild in reaction condition, high in yield and easy to industrialize, an amine-terminated functionalized structure is introduced to the surfaces of polymer particles and is combined with resin through chemical bonds when epoxy resin is cured, the toughening effect is achieved, and the service life of the polymer is prolonged. Therefore, the toughening problem of high-temperature cured epoxy resin is solved. Compared with the prior art, the raw material cost is low, the synthesis yield is high, the product is easy to purify, and the total reaction yield reaches 46.1%.

Description

Technical Field

[0001] The invention belongs to the technical field of organic chemistry, and in particular relates to a branched polyetherketoneketone polymer and a preparation method thereof. Background Art

[0002] Epoxy resin is a type of thermosetting resin, generally prepared by linear oligomers containing epoxy functional groups. It is a high-performance composite material matrix resin commonly used in the engineering field. Depending on the application field, epoxy oligomers with different skeleton structures, different functional groups, different epoxy values ​​and molecular weights can be selected for preparation. Epoxy resin can be cured by Lewis acid or base, but the most commonly used curing agent is amine curing agent, which forms a chemical cross-linking structure through epoxy ring opening.

[0003] Composite materials made of epoxy resin as the matrix and reinforced with glass fiber and carbon fiber have the characteristics of low density, high specific strength and specific modulus, high fatigue strength, good designability, good chemical corrosion resistance, and easy molding and processing. They have been widely used in aviation, aerospace, national defense, military industry, transportation and other fields. For example, in the field of modern fighters and large passenger aircraft, epoxy resin-based composite materials account for more than 20%. With the changes in application scenarios, especially in the manufacture of structural parts such as aircraft, satellites, solid rocket shells and spacecraft, higher requirements are placed on the heat resistance and high-temperature toughness of epoxy resin composite materials. It is well known that epoxy resins with high cross-linking degree have good heat resistance and mechanical properties, but will lead to a decrease in toughness; when the cross-linking degree is reduced and the toughness is improved, the heat resistance is significantly reduced. Therefore, the high-temperature toughening modification of epoxy resin has always been a hot topic of concern.

[0004] At present, the most commonly used epoxy toughening method is to use fiber fillers for toughening, such as carbon fiber and glass fiber fillers, or to add toughening particles, including rubber, silica, hollow microspheres and thermoplastics. However, when used for epoxy resin toughening, it is often difficult to mix evenly, easy to precipitate, and the high temperature resistance is reduced. In the field of composite materials, the development of thermoplastic particles that can be used as thermosetting resin toughening agents has important commercial value, especially polyetheramines (PEIs), polyaryletherketones (PAEKs) and polyarylethersulfones (PAESs), which can increase structural toughness while maintaining the modulus of the material. Each thermoplastic particle can serve as an energy absorption point and can also prevent the extension of the fracture damage of the thermosetting resin matrix. Polyethersulfone (PES) is soluble in uncured epoxy resin. When the epoxy resin is cured, the polyethersulfone will form small droplets and then form solid particles, achieve phase separation, and form particles suitable for cross-linking in situ, thereby achieving epoxy resin toughening. However, PES is amorphous and has poor solvent resistance, so it cannot be used in many fields. In contrast, PAEKs are semi-crystalline and solvent-resistant, but they are insoluble in uncured epoxy resins and require cryogenic grinding to prepare dispersible particles, which is a complex and costly process. In addition, the prepared particles have irregular shapes and uneven size distribution, making it impossible to obtain reliable mechanical properties. Moreover, many thermoplastic particles cannot withstand the high temperatures of 150°C required for the curing of thermosetting resins. Summary of the invention

[0005] In order to solve the problem of difficulty in toughening high temperature curing epoxy resin, the present invention provides a branched polyetherketoneketone polymer and a preparation method thereof.

[0006] The technical solution of the present invention:

[0007] A method for preparing a branched polyetherketoneketone polymer comprises the following steps:

[0008] Step 1: Preparation of terephthaloyl chloride:

[0009] Terephthalic acid, thionyl chloride and DMF are mixed in a certain material-liquid ratio, and reflux reaction is carried out under nitrogen protection, and then an ammonium chloride aqueous solution is added for washing, and terephthaloyl chloride is obtained by concentrating and distilling under reduced pressure;

[0010] Step 2: Preparation of ether-ketone-ketone-ether monomers:

[0011] The terephthaloyl chloride, diphenyl ether and dichloromethane obtained in step 1 are mixed in a certain material-liquid ratio, and stirred at low temperature under nitrogen protection to obtain an ether ketone ketone ether monomer;

[0012] Step 3: Synthesis of branched polyetherketoneketone polymer:

[0013] The ether ketone ketone ether monomer obtained in step 2, terephthaloyl chloride, trimesoyl chloride, isophthaloyl chloride, trifluoroacetamido diphenyl ether and dichloromethane obtained in step 1 are mixed, and an amino-protected branched polyether ketone ketone polymer is synthesized by a dispersion polymerization process under nitrogen protection.

[0014] Furthermore, the solid-liquid ratio of terephthalic acid, thionyl chloride and DMF in step 1 is 86.0-90 g: 155.6-160.0 g: 1000-1200 mL.

[0015] Furthermore, the temperature of the reflux reaction in step 1 is 162-168° C., and the time of the reflux reaction is 10-12 h.

[0016] Furthermore, the solid-liquid ratio of terephthaloyl chloride, diphenyl ether and dichloromethane in step 2 is 98.1-100.0 g: 37.0-40.0 g: 600-650 mL.

[0017] Furthermore, the temperature of the low-temperature stirring in step 2 is 0-5° C., and the stirring time is 4-5 h.

[0018] Furthermore, in step 3, the solid-liquid ratio of the ether ketone ketone ether monomer, terephthaloyl chloride, trimesoyl chloride, isophthaloyl chloride, trifluoroacetamido diphenyl ether and dichloromethane is 86.0-90g: 155.6-160.0g: 98.1-100.0g: 98.1-100.0g: 37.0-40.0g: 1000-1200mL.

[0019] Furthermore, the dispersion polymerization process in step 3 is to stir the reaction at room temperature for 10 to 12 hours.

[0020] A branched polyetherketoneketone polymer prepared by a preparation method of a branched polyetherketoneketone polymer.

[0021] Beneficial effects of the present invention:

[0022] The present invention provides a method for preparing a branched polyetherketoneketone polymer with low cost, mild reaction conditions, high yield and easy industrialization. Using terephthaloyl chloride, trimesoyl chloride and etherketone monomer as raw materials, and using an etherketone compound containing an amino group as a capping agent, a Friedel-Crafts acylation dispersion polymerization process is adopted to prepare amino-terminated functionalized polyetherketoneketone polymer particles (PEKK). The amine-terminated functionalized structure is introduced into the surface of the polymer particles, and the resin is combined with a chemical bond during the curing of the epoxy resin to obtain the aforementioned toughening effect, thereby solving the toughening problem of high-temperature cured epoxy resin. At the same time, the Friedel-Crafts acylation dispersion polymerization reaction mechanism is studied in depth to provide theoretical support for the preparation of amino-terminated polyaryletherketone polymers; the epoxy toughening mechanism of amino-terminated polyetherketoneketone particles is studied in depth to provide a theoretical basis for the preparation of heat-resistant and high-toughness epoxy resin-based composite materials.

[0023] The amino-terminated polyetheretherketone oligomer prepared by the method has excellent heat resistance and solvent resistance, and can be used for toughening of high-temperature cured epoxy resin. By reacting the amino-terminated group with the epoxy functional group, the aromatic ether ketone oligomer is introduced into the cured resin, so as to achieve the toughening purpose and eliminate the interface effect. The toughened epoxy resin composite material can be used for the manufacture of modern aerospace and aviation aircraft. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described below in conjunction with the embodiments, but it is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention shall be included in the protection scope of the present invention. The process equipment or devices not specifically noted in the following embodiments are all conventional equipment or devices in the art. If not specifically specified, the raw materials used in the embodiments of the present invention can be obtained commercially; if not specifically specified, the technical means used in the embodiments of the present invention are all conventional means well known to those skilled in the art.

[0025] Example 1

[0026] This embodiment provides a branched polyetherketoneketone polymer and a preparation method thereof.

[0027] The present embodiment provides a method for preparing a branched polyetherketoneketone polymer, comprising the following steps:

[0028] Step 1: Preparation of terephthaloyl chloride:

[0029] Under nitrogen atmosphere, 86.0 g of terephthalic acid, 155.6 g of thionyl chloride and 1000 mL of DMF were added to a three-necked flask, and the temperature was raised to 168°C for reflux reaction. The reaction progress was monitored by HPLC. After 10 h of reaction, terephthalic acid was completely reacted. After the reaction solution was cooled to room temperature, 500 mL of 10 wt% ammonium chloride aqueous solution was added, the water layer was separated, the water layer was extracted with toluene, the organic layers were combined, dried over anhydrous magnesium sulfate, filtered, concentrated under reduced pressure, and distilled to obtain terephthaloyl chloride;

[0030] Step 2: Preparation of ether-ketone-ketone-ether monomers:

[0031] Under nitrogen atmosphere, add terephthaloyl chloride 98.1g, diphenyl ether 37.0g and dichloromethane 600mL into a three-necked flask, keep 0℃, stir for 4h, the reaction liquid is light yellow paste, HPLC monitors the reaction progress, after 4h, the raw materials react completely, add 300mL of water after the reaction, evaporate dichloromethane under reduced pressure, filter and dry to obtain an off-white solid;

[0032] Step 3: Preparation of branched polyetherketoneketone polymer:

[0033] Under nitrogen atmosphere, 88 g of ether ketone ketone ether monomer, 155 g of terephthaloyl chloride, 98.1 g of trimesoyl chloride, 98.1 g of isophthaloyl chloride, 40 g of trifluoroacetamido diphenyl ether and 1000 mL of dichloromethane were added to a three-necked flask and reacted at room temperature for 10 h. The system state changed from a white suspension to an orange-yellow clear liquid and finally to a yellow viscous liquid. After the reaction, 500 mL of water was added, dichloromethane was evaporated under reduced pressure, and the off-white solid was obtained by filtration and drying.

[0034] The terephthaloyl chloride prepared in step 1 of this embodiment is a white solid with a yield of 151.3 g, a purity of 99.05%, and a yield of 92.5%.

[0035] The ether-ketone-ketone-ether monomer obtained in step 2 of this embodiment is a white solid with a yield of 108.9 g, a purity of 99.29%, and a yield of 87.0%.

[0036] The branched polyetherketoneketone polymer obtained in step 3 of this example is a white solid with a yield of 68.6 g, a purity of 99.08%, and a yield of 78.0%.

[0037] The total yield of the three-step reaction for preparing the branched polyetherketoneketone polymer in this example is 48.1%.

[0038] Example 2

[0039] This embodiment provides a branched polyetherketoneketone polymer and a preparation method thereof.

[0040] The present embodiment provides a method for preparing a branched polyetherketoneketone polymer, comprising the following steps:

[0041] Step 1: Preparation of terephthaloyl chloride:

[0042] Under nitrogen atmosphere, 90.0 g of terephthalic acid, 160.0 g of thionyl chloride and 1200 mL of DMF were added to a three-necked flask, and the temperature was raised to 168°C for reflux reaction. The reaction progress was monitored by HPLC. After 10 h of reaction, terephthalic acid was completely reacted. After the reaction solution was cooled to room temperature, 500 mL of 10 wt% ammonium chloride aqueous solution was added, the water layer was separated, the water layer was extracted with toluene, the organic layers were combined, dried over anhydrous magnesium sulfate, filtered, concentrated under reduced pressure, and distilled to obtain terephthaloyl chloride;

[0043] Step 2: Preparation of ether-ketone-ketone-ether monomers:

[0044] Under nitrogen atmosphere, add 100.0 g of terephthaloyl chloride, 40.0 g of diphenyl ether and 600 mL of dichloromethane into a three-necked flask, keep 0°C, stir for 4 h, the reaction liquid becomes light yellow paste, HPLC monitors the reaction progress, after 4 h, the raw materials react completely, after the reaction is completed, add 300 mL of water, evaporate dichloromethane under reduced pressure, filter and dry to obtain an off-white solid;

[0045] Step 3: Preparation of branched polyetherketoneketone polymer:

[0046] Under nitrogen atmosphere, 86 g of ether ketone ketone ether monomer, 155.6 g of terephthaloyl chloride, 98.1 g of trimesoyl chloride, 98.1 g of isophthaloyl chloride, 40 g of trifluoroacetamido diphenyl ether and 1200 mL of dichloromethane were added to a three-necked flask and reacted at room temperature for 10 h. The system state changed from a white suspension to an orange-yellow clear liquid and finally to a yellow viscous liquid. After the reaction, 500 mL of water was added, dichloromethane was evaporated under reduced pressure, and the off-white solid was obtained by filtration and drying.

[0047] Example 3

[0048] This embodiment provides a branched polyetherketoneketone polymer and a preparation method thereof.

[0049] The present embodiment provides a method for preparing a branched polyetherketoneketone polymer, comprising the following steps:

[0050] Step 1: Preparation of terephthaloyl chloride:

[0051] Under nitrogen atmosphere, 88.0 g of terephthalic acid, 158 g of thionyl chloride and 1100 mL of DMF were added to a three-necked flask, and the temperature was raised to 168°C for reflux reaction. The reaction progress was monitored by HPLC. After 10 h of reaction, terephthalic acid was completely reacted. After the reaction solution was cooled to room temperature, 500 mL of 10 wt% ammonium chloride aqueous solution was added, the water layer was separated, the water layer was extracted with toluene, the organic layers were combined, dried over anhydrous magnesium sulfate, filtered, concentrated under reduced pressure, and distilled to obtain terephthaloyl chloride;

[0052] Step 2: Preparation of ether-ketone-ketone-ether monomers:

[0053] Under nitrogen atmosphere, 99 g of terephthaloyl chloride, 38.0 g of diphenyl ether and 650 mL of dichloromethane were added to a three-necked flask, maintained at 0°C, and stirred for 4 h. The reaction liquid was light yellow paste. The reaction progress was monitored by HPLC. After 4 h of reaction, the raw materials were completely reacted. After the reaction was completed, 300 mL of water was added, dichloromethane was evaporated under reduced pressure, and an off-white solid was obtained by filtration and drying.

[0054] Step 3: Preparation of branched polyetherketoneketone polymer:

[0055] Under nitrogen atmosphere, 90 g of ether ketone ketone ether monomer, 160 g of terephthaloyl chloride, 100 g of trimesoyl chloride, 100 g of isophthaloyl chloride, 38 g of trifluoroacetylamino diphenyl ether and 1100 mL of dichloromethane were added to a three-necked flask and reacted at room temperature for 10 h. The system state changed from a white suspension to an orange-yellow clear liquid and finally to a yellow viscous liquid. After the reaction, 500 mL of water was added, dichloromethane was evaporated under reduced pressure, and the off-white solid was obtained by filtration and drying.

[0056] Example 4

[0057] This embodiment provides a branched polyetherketoneketone polymer and a preparation method thereof.

[0058] The present embodiment provides a method for preparing a branched polyetherketoneketone polymer, comprising the following steps:

[0059] Step 1: Preparation of terephthaloyl chloride:

[0060] Under nitrogen atmosphere, 87.0 g of terephthalic acid, 160 g of thionyl chloride and 1000 mL of DMF were added to a three-necked flask, and the temperature was raised to 165°C for reflux reaction. The reaction progress was monitored by HPLC. After 12 hours of reaction, terephthalic acid was completely reacted. After the reaction solution was cooled to room temperature, 500 mL of 10 wt% ammonium chloride aqueous solution was added, the water layer was separated, the water layer was extracted with toluene, the organic layers were combined, dried over anhydrous magnesium sulfate, filtered, concentrated under reduced pressure, and distilled to obtain terephthaloyl chloride;

[0061] Step 2: Preparation of ether-ketone-ketone-ether monomers:

[0062] Under nitrogen atmosphere, add terephthaloyl chloride 99g, diphenyl ether 38.0g and dichloromethane 600mL into a three-necked flask, keep 0℃, stir for 5h, the reaction liquid is light yellow paste, HPLC monitors the reaction progress, after 4h, the raw materials react completely, add 300mL of water after the reaction, evaporate dichloromethane under reduced pressure, filter and dry to obtain an off-white solid;

[0063] Step 3: Preparation of branched polyetherketoneketone polymer:

[0064] Under nitrogen atmosphere, 88 g of ether ketone ketone ether monomer, 160 g of terephthaloyl chloride, 100 g of trimesoyl chloride, 100 g of isophthaloyl chloride, 38 g of trifluoroacetylamino diphenyl ether and 1200 mL of dichloromethane were added to a three-necked flask and reacted at room temperature for 10 h. The system state changed from a white suspension to an orange-yellow clear liquid and finally to a yellow viscous liquid. After the reaction, 500 mL of water was added, dichloromethane was evaporated under reduced pressure, and the off-white solid was obtained by filtration and drying.

[0065] The present invention is described in conjunction with specific embodiments in the above description, but it should be understood that these descriptions are only for a better understanding of the present invention and do not constitute any limitation of the present invention. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a branched polyetherketoneketone polymer, characterized in that: The steps include: Step 1: Preparation of terephthaloyl chloride: Terephthalic acid, thionyl chloride and DMF are mixed in a certain material-liquid ratio, and reflux reaction is carried out under nitrogen protection, and after reflux reaction, ammonium chloride aqueous solution is added for washing, and terephthaloyl chloride is obtained by concentration and distillation under reduced pressure; Step 2: Preparation of ether-ketone-ketone-ether monomers: The terephthaloyl chloride, diphenyl ether and dichloromethane obtained in step 1 are mixed in a certain material-liquid ratio, and stirred at low temperature under nitrogen protection to obtain an ether ketone ketone ether monomer; Step 3: Synthesis of branched polyetherketoneketone polymer: The ether ketone ketone ether monomer obtained in step 2, terephthaloyl chloride, trimesoyl chloride, isophthaloyl chloride, trifluoroacetamido diphenyl ether and dichloromethane obtained in step 1 are mixed, and an amino-protected branched polyether ketone ketone polymer is synthesized by a dispersion polymerization process under nitrogen protection.

2. The method for preparing a branched polyetherketoneketone polymer according to claim 1, characterized in that: The solid-liquid ratio of terephthalic acid, thionyl chloride and DMF in step 1 is 86.0-90 g: 155.6-160.0 g: 1000-1200 mL.

3. The method for preparing a branched polyetherketoneketone polymer according to claim 1 or 2, characterized in that: The temperature of the reflux reaction in step 1 is 162-168° C., and the time of the reflux reaction is 10-12 h.

4. The method for preparing a branched polyetherketoneketone polymer according to claim 3, characterized in that: The solid-liquid ratio of terephthaloyl chloride, diphenyl ether and dichloromethane in step 2 is 98.1-100.0 g: 37.0-40.0 g: 600-650 mL.

5. The method for preparing a branched polyetherketoneketone polymer according to claim 4, characterized in that: The temperature of the low-temperature stirring in step 2 is 0-5°C, and the stirring time is 4-5h.

6. The method for preparing a branched polyetherketoneketone polymer according to claim 5, characterized in that: In step 3, the solid-liquid ratio of the ether-ketone-ketone-ether monomer, terephthaloyl chloride, trimesoyl chloride, isophthaloyl chloride, trifluoroacetamido diphenyl ether and dichloromethane is 86.0-90g: 155.6-160.0g: 98.1-100.0g: 98.1-100.0g: 37.0-40.0g: 1000-1200mL.

7. The method for preparing a branched polyetherketoneketone polymer according to claim 6, characterized in that: The dispersion polymerization process in step 3 is to stir the reaction at room temperature for 10 to 12 hours.

8. A dendritic polyetherketoneketone polymer prepared by the method for preparing a dendritic polyetherketoneketone polymer according to any one of claims 1 to 7.