A method for preparing polyetherketoneketone and the product obtained therefrom

Abstract

The present invention relates to a method for preparing polyetherketoneketone and a product obtained thereof. The method comprises: preparing a bis(4-halogenated phenyl ether) Grignard reagent by using bis(4-halogenated phenyl ether) and reacting the Grignard reagent with dioctyl terephthalate, terephthaloyl chloride, isophthaloyl chloride and terephthalonitrile to prepare polyetherketoneketone; or preparing a phenylene bisGrignard reagent by using p-dihalobenzene and reacting the bis(4-halogenated phenyl ether) Grignard reagent with dioctyl terephthalate ether, dibenzoyl chloride ether, diisobenzoyl chloride ether and dibenzonitrile ether to prepare polyetherketoneketone. The preparation method comprises: ultrasonically reacting bis(4-halogenated phenyl ether) or p-dihalobenzene, iodine and tetrahydrofuran at 50°C for 20 min under an inert atmosphere to prepare a bisGrignard reagent, and reacting the prepared bisGrignard reagent with dibasic ester, dibasic acyl halide or dibasic nitrile for 12 h under an inert atmosphere to obtain polyetherketoneketone with different molecular weights through purification. The polyetherketoneketone prepared by the method has many advantages such as high regularity, strong heat resistance, simple process and low cost.

Description

Technical Field

[0001] The invention relates to the technical field of drug synthesis, and in particular to a method for preparing polyetherketoneketone and a product obtained therefrom. Background Art

[0002] Polyetherketoneketone (PEKK) belongs to the special engineering plastic polyaryletherketone (PEAK) series. PEAK is a type of polymer formed by connecting phenylene rings through ether bonds and carbonyl groups. According to the different connection order and proportion of ether bonds, ketone groups and benzene rings in the molecular chain, many different polymers can be formed. In addition to polyetherketoneketone, there are also polyetherketone (PEK), polyetheretherketone (PEEK), polyetheretherketoneketone (PEEKK), polyetherketoneetherketoneketone (PEKEKK), etc. Polyetherketoneketone is another thermoplastic resin with a special structure developed after polyetheretherketone. It has excellent mechanical properties, solvent resistance and chemical corrosion resistance, heat resistance, radiation resistance and flame retardancy. It is particularly suitable for use as a matrix resin for high-performance composite materials and super engineering materials.

[0003] Compared with general plastics, polyetherketoneketone has higher heat resistance, rigidity, mechanical properties and wear resistance. Many characteristics are similar to metals, but with low density and simple molding and processing, it has a wide range of industry application prospects. Due to its excellent comprehensive performance, polyaryletherketone has extremely high application demand in aerospace, automobile manufacturing and other fields. It is one of the very few structural materials for aerospace and deep space exploration equipment that has passed the NASA system verification. With the rise of application technologies such as additive manufacturing, thermoplastic composites and nano injection molding, the development of polyaryletherketone materials such as polyetherketoneketone has been further promoted. Polyetherketoneketone fine powder and ultrafine powder can be used in various application fields such as high temperature resistant and anti-corrosion non-stick coatings, fiber reinforced high-performance thermoplastic prepreg composite materials, modified particles, molded pipe segment plate rods, etc. In addition, polyetherketoneketone is also used in long-term human medical implants and downhole equipment in the oil and gas industry, becoming a hot spot in the field of polymer material research.

[0004] At present, polyetherketoneketone can be produced through two different reactions, one is nucleophilic substitution reaction and the other is electrophilic substitution reaction. Nucleophilic substitution reaction generally requires expensive aromatic difluoride and bisphenol A as monomers, diphenyl sulfone as solvent, K2CO3 / NaCO3 as catalyst, and the synthesized PEKK has stable performance and high purity, but the reaction conditions are complex, the cost is high, and the glass transition temperature is low; electrophilic substitution reaction generally uses cheap aromatic acyl chloride and diphenyl ether as reactants, dichloromethane as solvent, AlCl3 as catalyst, and obtains polyetherketoneketone with higher molar mass through Friedel-Crafts acylation reaction, which is the most commonly used method for synthesizing polyetherketoneketone. Most of the syntheses of polyetherketoneketone that have been reported so far use precipitation polymerization system, that is, 1,2-dichloroethane as solvent, AlCl3 as catalyst, and aromatic diacyl chloride and aromatic ether are condensed through Friedel-Crafts acylation reaction. Since polyetherketoneketone is difficult to dissolve in general solvents, it often precipitates during the polymerization process. Since the complex of AlCl3 and Lewis base can be dissolved in dichloromethane, a series of polyaryletherketones were synthesized in the presence of Lewis base using AlCl3 as catalyst and dichloromethane as solvent. Although the problem of resin separation and purification was solved, the reaction time was long and side reactions such as polymer branching were not completely overcome.

[0005] Based on the needs of industry and practical applications, it is necessary to find a synthesis method with simple process, low cost and few side reactions such as branching. Summary of the invention

[0006] The purpose of the present invention is to synthesize linear polyetherketoneketone by stepwise polymerization using highly selective di-Grignard reagents to react with dibasic acid chlorides, dibasic esters and dibasic nitriles, so as to solve the problems of high branching degree and more side reactions in the existing methods.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A method for preparing polyetherketoneketone comprises the following general reaction formula:

[0009]

[0010] or

[0011] ;

[0012] X = F, Cl, Br, I;

[0013] Y=COOR”, COX, CN;

[0014] R includes one or more of hydrogen, alkyl, aryl or alicyclic group, halogen, sulfonic acid group, and nitro group;

[0015] R' includes one or more of hydrogen, alkyl, aryl or alicyclic group, halogen, sulfonic acid group, and nitro group;

[0016] R" includes one or more of an alkyl group, an aryl group or an alicyclic group.

[0017] The polyetherketoneketone prepared by the method of the present invention is characterized in that the branching degree is low, the product is a linear polyetherketoneketone, the molecular weight is controllable, the product particle size is controllable, and the product has good heat resistance.

[0018] The molecular weight of the polyetherketoneketone can be controlled by feed ratio, reaction time and reaction temperature; the structure of the product can be regulated by copolymerization.

[0019] Preferably, the method comprises the following steps:

[0020] A. Obtain double Grignard reagent;

[0021] B. Dissolving the polymerizable monomer in a reaction solvent, and under the protection of an inert gas, dripping the di-Grignard reagent to carry out a polymerization reaction to obtain a crude product; the polymerizable monomer includes one or more of a dibasic acyl halide, a dibasic ester, and a dibasic nitrile; dripping the di-Grignard reagent under the protection of an inert gas can prevent the di-Grignard reagent from reacting with oxygen and water in the air, thereby reducing by-products.

[0022] C. Purify the crude product to obtain polyetherketoneketone.

[0023] The polymerizable monomer is one or more of 4,4'-dichlorodiphenyl ether, 4,4'-dibromodiphenyl ether, terephthaloyl chloride, terephthaloyl bromide, isophthaloyl chloride, terephthaloyl bromide, dimethyl terephthalate, diethyl terephthalate, dibutyl terephthalate, dioctyl terephthalate, terephthalonitrile or substituted groups thereof.

[0024] Preferably, the operation of step A comprises: mixing iodine particles, dihalogenated aromatic hydrocarbons, and magnesium powder in a reaction solvent, heating and performing ultrasonic reaction under the protection of an inert gas to obtain the bis-Grignard reagent; the dihalogenated aromatic hydrocarbons include p-dichlorobenzene, p-dibromobenzene, m-dichlorobenzene, m-dibromobenzene, bis(4-fluorophenyl) ether, bis(4-chlorophenyl) ether, bis(4-bromophenyl) ether, bis(4-iodophenyl) ether, and one or more of their derivatives containing substituents, such as derivatives containing substituents such as methyl.

[0025] Preferably, in step A, the molar ratio of the dihalogenated aromatic hydrocarbon to the magnesium powder is 1:3; the ultrasonic power of the ultrasonic reaction is 300-1500 W, the reaction temperature is 20° C.-50° C., and the reaction time is 20-35 min.

[0026] Preferably, the inert gas includes one or more of nitrogen and argon; and the reaction solvent includes tetrahydrofuran.

[0027] Preferably, in step B, the dropping process of the di-Grignard reagent includes slow dropping and rapid stirring, and the dropping time includes 0.1 to 1 hour; the reaction temperature of the polymerization reaction includes 20 to 50° C., and the reaction time includes 12 to 24 hours.

[0028] The double Grignard reagent needs to be added slowly, with a total addition time of 0.1 to 1 hour being appropriate, to prevent the reaction from being too violent and causing side reactions.

[0029] Preferably, when the polymerizable monomer includes a diacyl halide, the purification treatment in step C includes: adding an acid to the crude product and washing with water, then adding an alkali to wash, filtering and washing with water until neutral, washing with an organic solvent, and drying to obtain the polyetherketoneketone;

[0030] When the polymerizable monomer includes a dibasic ester, the purification treatment in step C includes: adding an acid agent to the crude product, washing with water and an alcohol agent in sequence, and precipitating in the alcohol agent to obtain the polyetherketoneketone;

[0031] When the polymerizable monomer includes a dinitrile, the purification treatment in step C includes: adding an acid agent, washing with water and an alcohol agent in sequence, extracting with an alcohol agent and precipitating in an alcohol agent to obtain the polyetherketoneketone.

[0032] When different raw materials are used, the small molecular byproducts produced by the polymerization reaction are different, and the molecular weight of the products is also different. Therefore, different methods are required for purification.

[0033] The acid is a quencher, which mainly quenches the double Grignard reagent and reacts with the remaining double Grignard reagent. Alcohol or water can also be used as a quencher. In the reaction system of this scheme, quenching with an organic acid is beneficial to post-treatment and is a preferred result.

[0034] During purification, the particle size of the polyetherketoneketone is screened by filter papers or filter membranes with different pore sizes to obtain polyetherketoneketone for different purposes.

[0035] Preferably, in step C, the acidic agent includes one or more of formic acid, acetic acid, and butyric acid, the alkaline agent includes sodium hydroxide solution, and the alcohol agent includes one or more of methanol, ethanol, and butanol.

[0036] A polyetherketoneketone product obtained by the method for preparing polyetherketoneketone.

[0037] The polyetherketoneketone product prepared by the method of the present invention has the characteristics of high regularity, strong heat resistance and the like, and can be used as special engineering plastics, coatings and composite materials.

[0038] Preferably, the polyetherketoneketone product is a linear polyetherketoneketone.

[0039] The preparation method of the present invention has a low degree of branching, and the product is a linear polyetherketoneketone, the molecular weight is controllable, the product particle size is controllable, the product has good heat resistance, and the thermal performance is stable. The molecular weight of the polyetherketoneketone can be controlled by the feed ratio, reaction time, and reaction temperature; the structure of the product can be regulated by copolymerization. The particle size of the product can be screened by the pore size of the filter cloth, and there are differences in its properties and applications. The pore size of the filter cloth can be selected from 200 mesh to 1000 mesh. The products screened under different pore sizes are mainly different in molecular weight, resulting in different properties. The small molecular weight product can be used for coatings and the like, and the large molecular weight product can be used as special plastics and the like.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present invention uses bis(4-halogenated phenyl ether) to prepare bis(4-halogenated magnesium phenyl ether) Grignard reagent, which reacts with dioctyl terephthalate, terephthaloyl chloride, isophthaloyl chloride and terephthalonitrile to prepare polyether ketone ketones of different molecular weights; or uses p-dihalobenzene to prepare phenylene bis-Grignard reagent, which reacts with di-dioctyl terephthalate ether, di-dibenzoyl chloride ether, di-isobenzoyl chloride ether and di-dibenzonitrile ether to prepare polyether ketone ketones of different molecular weights. The preparation is as follows: bis(4-halogenated phenyl ether) or p-dihalobenzene, iodine and tetrahydrofuran are heated to 50°C and ultrasonically reacted for 20 minutes under an argon environment to prepare bis(4-bromide magnesium phenyl ether) Grignard reagent or phenylene bis-Grignard reagent; and a tetrahydrofuran solution of the prepared bis-Grignard reagent is reacted with dibasic ester, dibasic acyl halide or dibasic nitrile for 12 hours under a nitrogen environment, and polyether ketone ketones of different molecular weights are obtained after purification. The polyetherketoneketone prepared by the method has many advantages such as high regularity, strong heat resistance, simple process and low cost.

[0042] The invention has a simple preparation process, high activity and good selectivity of the double Grignard reagent, and can prepare linear polyetherketoneketone with high regularity under mild conditions. Polyetherketoneketone with different molecular weights can be prepared by controlling the reaction temperature, time, feed ratio and substrate selection. The particle size of the polyetherketoneketone is screened by controlling the pore size of the filter paper or the filter membrane.

[0043] Compared with the existing methods, the present invention prepares polyetherketoneketone by using a di-Grignard reagent with dibasic acid chloride, dibasic ester and dibasic nitrile, and the reaction conditions are mild, the reaction time is short, the operation is simple and the reactants are cheap. The reactant selectivity is high, the occurrence of side reactions such as branching is effectively reduced, and a linear polyetherketoneketone with high regularity is prepared, which has high heat resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is the infrared spectrum of polyetherketoneketone prepared in Example 1 of the present invention.

[0045] Figure 2 This is the solid state NMR carbon spectrum of polyetherketoneketone prepared in Example 1 of the present invention.

[0046] Figure 3 This is the thermogravimetric analysis diagram of polyetherketoneketone prepared in Example 1 of the present invention.

[0047] Figure 4 This is the differential scanning calorimetry diagram of polyetherketoneketone prepared in Example 1 of the present invention.

[0048] Figure 5 This is the GPC spectrum of polyetherketoneketone prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0049] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings.

[0050] Example 1

[0051] Add 3.54 g of p-dibromobenzene, 0.01 g of iodine, and 40 mL of tetrahydrofuran to a dry Schlenk bottle, evacuate and replace argon three times, and ultrasonically heat at 40°C for 20 min to prepare p-dibromobenzene di-Grignard reagent. Add 4.43 g of 4,4'-diacyl chloride diphenyl ether and 40 mL of tetrahydrofuran to a dry two-necked bottle, evacuate and replace argon three times. Slowly drop p-dibromobenzene di-Grignard reagent into the two-necked bottle, stir rapidly, and react at room temperature for 12 h. Add 40 mL of 36% acetic acid solution to the two-necked bottle and stir at room temperature for 3 h. Filter, take the upper layer of powder and put it into a single-necked bottle, add 50 mL of 20% sodium hydroxide solution, and ultrasonicate for 20 min. Filter, take the upper layer of powder and wash with water until neutral. Wash with a large amount of tetrahydrofuran and dry. Polyetherketoneketone is obtained.

[0052] The polyetherketoneketone prepared by the method of the present invention has a melting point of 348°C, a temperature of 456°C when the weight loss is 5%, a weight loss of 66% at 800°C, and a characteristic viscosity of a 0.5% polyetherketoneketone concentrated sulfuric acid solution of 0.608 dL / g.

[0053] Example 2

[0054] Add 3.05 g of bis(4-bromophenyl)ether, 0.01 g of iodine, and 40 mL of tetrahydrofuran to a dry Schlenk bottle, evacuate and replace argon three times, and ultrasonically heat at 40°C for 35 min to prepare bis(4-bromophenyl)ether bisGrignard reagent. Add 5.95 mL of dioctyl terephthalate and 40 mL of tetrahydrofuran to a dry two-necked bottle, evacuate and replace argon three times. Slowly drop bis(4-bromophenyl)ether bisGrignard reagent into the two-necked bottle, stir rapidly, and react at room temperature for 12 h. Add 40 mL of 36% formic acid solution to the two-necked bottle and stir at room temperature for 1 h. Evaporate to dryness by rotary evaporation. Wash with water and ethanol, and dry. Add a small amount of tetrahydrofuran to dissolve and precipitate in ethanol. Filter and dry. Polyetherketoneketone is obtained.

[0055] The polyetherketoneketone prepared by the method of the present invention has a number average molecular weight of 8039 g / mol and a weight average molecular weight of 27977 g / mol.

[0056] Example 3

[0057] Add 3.05 g of bis(4-bromophenyl)ether, 0.01 g of iodine, and 40 mL of tetrahydrofuran to a dry Schlenk bottle, evacuate and replace argon three times, and ultrasonically heat at 40°C for 35 min to prepare bis(4-bromophenyl)ether bisGrignard reagent. Add 1.92 g of terephthalonitrile and 40 mL of tetrahydrofuran to a dry two-necked bottle, evacuate and replace argon three times. Slowly drop bis(4-bromophenyl)ether bisGrignard reagent into the two-necked bottle, stir rapidly, and react at room temperature for 12 h. Add 40 mL of 36% butyric acid solution to the two-necked bottle and stir at room temperature for 1 h. Evaporate to dryness by rotary evaporation. Wash with water and ethanol, extract with ethanol for 24 h, and dry. Add a small amount of tetrahydrofuran to dissolve and precipitate in ethanol. Filter and dry. Polyetherketoneketone is obtained.

[0058] The polyetherketoneketone prepared by the method of the present invention has a number average molecular weight of 76300 g / mol and a weight average molecular weight of 1141 g / mol.

[0059] Effect Example 1

[0060] In Example 2-3, dimethyl terephthalate, diethyl terephthalate, dibutyl terephthalate, dioctyl terephthalate, terephthaloyl chloride, isophthaloyl chloride, and terephthalonitrile can be replaced with each other.

[0061] The polyetherketoneketone prepared by the method described in Examples 1-3 was characterized by infrared, solid-state nuclear magnetic resonance, TGA, DSC, and GPC. Figure 1-5 As shown, polyetherketoneketone is obtained, and the spectra of other embodiments are similar and are not listed one by one. Figure 1 , Figure 2 The structure of the polyetherketoneketone prepared by the present invention is characterized. Figure 3 It can be seen that the decomposition temperature is high, indicating that the structure is relatively regular. Figure 4 It further illustrates that crystallization is possible. Figure 5 This shows that there is a suitable molecular weight distribution. Figure 1-5 This indicates that the polyetherketoneketone with a regular and stable structure is obtained in the present invention, which is suitable for wide promotion and application.

[0062] The above disclosure is only the preferred embodiment of the present invention, which cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for preparing polyetherketoneketone, characterized in that: The reaction formula includes the following: or ； X = F, Cl, Br, I; Y=COOR”, COX, CN; R includes one or more of hydrogen, alkyl, aryl or alicyclic group, halogen, sulfonic acid group, and nitro group; R' includes one or more of hydrogen, alkyl, aryl or alicyclic group, halogen, sulfonic acid group, and nitro group; R" includes one or more of an alkyl group, an aryl group or an alicyclic group.

2. The method for preparing polyetherketoneketone according to claim 1, characterized in that: The steps include: A. Obtain double Grignard reagent; B. dissolving a polymerization monomer in a reaction solvent, and under the protection of an inert gas, dropwise adding the di-Grignard reagent to carry out a polymerization reaction to obtain a crude product; the polymerization monomer comprises one or more of a dibasic acyl halide, a dibasic ester, and a dibasic nitrile; C. Purify the crude product to obtain polyetherketoneketone.

3. The method for preparing polyetherketoneketone according to claim 2, characterized in that: The operation of step A comprises: mixing iodine particles, dihalogenated aromatic hydrocarbons and magnesium powder in a reaction solvent, heating and performing ultrasonic reaction under the protection of an inert gas to obtain the di-Grignard reagent; the dihalogenated aromatic hydrocarbons comprise one or more of p-dichlorobenzene, p-dibromobenzene, m-dichlorobenzene, m-dibromobenzene, bis(4-fluorophenyl) ether, bis(4-chlorophenyl) ether, bis(4-bromophenyl) ether, bis(4-iodophenyl) ether and derivatives thereof containing substituents.

4. The method for preparing polyetherketoneketone according to claim 3, characterized in that: In step A, the molar ratio of the dihalogenated aromatic hydrocarbon to the magnesium powder is 1:3; the ultrasonic power of the ultrasonic reaction is 300-1500 W, the reaction temperature is 20° C.-50° C., and the reaction time is 20-35 min.

5. The method for preparing polyetherketoneketone according to claim 2, characterized in that: The inert gas includes one or more of nitrogen and argon; the reaction solvent includes tetrahydrofuran.

6. The method for preparing polyetherketoneketone according to claim 2, characterized in that: In step B, the dropping process of the double Grignard reagent includes slow dropping and rapid stirring, and the dropping time is 0.1 to 1 hour; the reaction temperature of the polymerization reaction is 20 to 50° C., and the reaction time is 12 to 24 hours.

7. The method for preparing polyetherketoneketone according to claim 2, characterized in that: When the polymerizable monomer includes a dibasic acyl halide, the purification treatment in step C includes: adding an acid to the crude product and washing with water, then adding an alkali to wash, filtering and washing with water until neutral, washing with an organic solvent, and drying to obtain the polyetherketoneketone; When the polymerizable monomer includes a dibasic ester, the purification treatment in step C includes: adding an acid agent to the crude product, washing with water and an alcohol agent in sequence, and precipitating in the alcohol agent to obtain the polyetherketoneketone; When the polymerizable monomer includes a dinitrile, the purification treatment in step C includes: adding an acid agent, washing with water and an alcohol agent in sequence, extracting with an alcohol agent and precipitating in an alcohol agent to obtain the polyetherketoneketone.

8. The method for preparing polyetherketoneketone according to claim 7, characterized in that: In step C, the acidic agent includes one or more of formic acid, acetic acid, and butyric acid, the alkaline agent includes sodium hydroxide solution, and the alcoholic agent includes one or more of methanol, ethanol, and butanol.

9. A polyetherketoneketone product obtained by the method for preparing polyetherketoneketone as claimed in claim 1.

10. The polyetherketoneketone product according to claim 9, characterized in that: The polyetherketoneketone product is a linear polyetherketoneketone.

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