High-crystallinity polyaryletherketone nitrile and preparation method thereof

Abstract

The invention relates to high-crystallinity polyaryletherketone nitrile and a preparation method thereof, and belongs to the technical field of high polymer material synthesis. The preparation method of the high-crystallinity polyaryletherketone nitrile comprises the following steps: A, preparation of phenate: under the protection of inert gas, mixing hydroquinone, a catalyst and N-methyl pyrrolidone, heating, carrying out a salt forming reaction, and removing moisture through entrainment of flowing inert gas to obtain a hydroquinone salt solution; b, prepolymerization: adding an N-methyl pyrrolidone solution of 4, 4-difluorobenzophenone and 2, 6-dichlorobenzonitrile into the hydroquinone salt solution obtained in the step A, and heating and prepolymerizing in an inert atmosphere of 0.1-2.0 MPa to obtain a prepolymer; and C, heating and polymerizing: polymerizing the prepolymer obtained in the step B at 240-260 DEG C under the pressure of 1-2 MPa to obtain a high-molecular-weight crystalline polyaryletherketone nitrile polymer solution. The preparation method is free of a dehydrating agent, so that residual pollution is avoided, and post-treatment is simplified.

Description

Technical Field

[0001] The present invention relates to a highly crystalline polyaryletherketonenitrile and a preparation method thereof, belonging to the technical field of polymer material synthesis. Background Art

[0002] Polyaryletherketonenitrile is a kind of special engineering plastic containing a large number of benzene rings, ether bonds, polar ketone groups and nitrile group side chains, combining the excellent properties of both polyarylether nitrile (PEEN) and polyetheretherketone (PEEK). It has properties such as high heat resistance, good flame retardancy, chemical corrosion resistance, wear resistance and high mechanical strength. Up to now, researchers at home and abroad have carried out a large number of works on the synthesis process and performance optimization of highly crystalline PEEN and PEEK. Imperial Chemical Industries in the UK used diphenyl sulfone as a solvent and carried out a polymerization reaction near the melting point of PEEK (~320 °C) to ensure that the product does not precipitate from the solvent before the molecular weight grows high enough, and successfully developed high molecular weight PEEK (trade name Victrex PEEK), taking the lead in realizing the industrialization of PEEK. However, diphenyl sulfone is insoluble in water, and in the process of product purification, it must be first extracted with organic solvents (such as methanol, acetone, etc.), and then washed with deionized water multiple times to remove by-product salts to obtain a refined PEEK product. In the mid-1980s, Idemitsu Kosan Co., Ltd. in Japan took 2,6-difluorobenzonitrile and resorcinol as raw materials and took the lead in launching a commercial high molecular weight crystalline polyarylether nitrile (trade brand PEEN-ID300), but there has been no subsequent report. However, domestic scholars have also carried out detailed research on highly crystalline PEEN, but highly crystalline PEEN is prone to precipitate during the synthesis process, resulting in difficulty in obtaining PEEN with the expected molecular weight. To solve the problem of precipitation during the synthesis of highly crystalline PEEN, both Patent CN112625233A and Patent CN117924689A take 2,6-difluorobenzonitrile and resorcinol as the main raw materials and toluene as a dehydrating agent, and then introduce a third monomer (bisphenol A and biphenol) respectively. However, the introduction of bisphenol A and biphenol both reduces the crystallinity, mechanical properties and heat resistance of PEEN to a certain extent, restricting its practical application. In addition, the dehydrating agent needs to be separated twice and its residual amount is difficult to control, and the separation of the dehydrating agent is difficult, and the residual toluene will reduce the product purity and temperature resistance.

[0003] In view of this, it is necessary to provide a method for synthesizing highly crystalline polyaryletherketonenitrile without a dehydrating agent, which has very important significance.

[0004] Patent CN107417907A discloses a preparation method of highly crystalline polyarylether nitrile, which relates to the technical field of polymer materials. In the present invention, a strong base solution is first reacted with a diphenol to form a phenolate, and then the dried phenolate is reacted with a dihalobenzonitrile in the presence of a carbonate and N-methylpyrrolidone under high temperature and pressure conditions to form an oligomer; the obtained oligomer is washed and dried and then subjected to the above polymerization reaction again to obtain a high molecular weight polymer; and then through pulverization, washing, and drying, a highly crystalline polyarylether nitrile resin is prepared. The present invention reduces

[0005] the content of inorganic salts in the synthesis system of the high molecular weight polymer, reduces the degree of crystallization precipitation during the polymerization reaction, and the prepared resin has improved heat resistance and mechanical properties due to its high crystallinity and large molecular weight. It can be used in high temperature, high acid and alkaline environments, can expand the application fields of PEN, and better meet the development needs of related fields. However, CN107417907A uses a mixed salt during the salt formation process, making the recovery more difficult; after the polymerization is completed, a pulverizer is used to pulverize the product into powder, the operation process is complex and energy-consuming, and at the same time, the performance of the polymer is likely to decline during the high-speed pulverization process; during the synthesis process, the preparation of phenolate is carried out first, and after the formation of phenolate, crystallization, separation and drying are carried out. The process operation is complex and discontinuous. At the same time, the phenolate is easily oxidized and discolored under high temperature and mild oxygen in this process, resulting in the instability of the synthesized product; the flexural strength and the notched impact strength of the simply supported beam are both relatively low and need to be further improved. Summary of the Invention

[0006] The first object of the present invention is to provide a preparation method of highly crystalline polyarylether ketone nitrile.

[0007] To achieve the first object of the present invention, the preparation method of the highly crystalline polyarylether ketone nitrile includes:

[0008] A. Preparation of phenolate: Under the protection of an inert gas, hydroquinone, a catalyst and N-methylpyrrolidone are mixed and then heated for a salt formation reaction, and water is removed by entrainment with a flowing inert gas to obtain a hydroquinone salt solution;

[0009] B. Prepolymerization: Add an N-methylpyrrolidone solution of 4,4-difluorobenzophenone and 2,6-dichlorobenzonitrile to the hydroquinone salt solution described in step A, and heat and prepolymerize in an inert atmosphere of 0.1-2.0 MPa to obtain a prepolymer;

[0010] C. Temperature-raising polymerization: Polymerize the prepolymer described in step B at 1-2 MPa and 240-260 °C to obtain a high molecular weight crystalline polyarylether ketone nitrile polymer solution;

[0011] D. Phase separation: Pump deionized water into the polymerization solution at a high pressure of 2-2.5 MPa for phase separation, and then stir at 220-240 °C to obtain a polyarylether ketone nitrile slurry.

[0012] The inert atmosphere uses an inert gas, and the inert gas is a gas that does not react with the reaction system.

[0013] The stirring in step D has no special requirements. For example, ordinary frame stirring is fine, and the rotation speed is 60 - 80 rpm.

[0014] In a specific embodiment, the temperature of the salt formation reaction in step A is 140 - 150 °C, preferably 140 - 145 °C, the reaction time is 2 - 4 hours, preferably 3 h; preferably, the flow rate of the flowing inert gas in step A is 0.5 - 4 m 3 / h, more preferably 2 m 3 / h.

[0015] In a specific embodiment, the molar ratio of hydroquinone, catalyst, and N - methylpyrrolidone in step A is 1:1 - 1.5:5 - 20; preferably 1:1.2:5 - 20.

[0016] In a specific embodiment, the catalyst in step A includes one of potassium carbonate, sodium carbonate, potassium bicarbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, and is preferably potassium carbonate.

[0017] In a specific embodiment, the molar ratio of 2,6 - dichlorobenzonitrile to 4,4 - difluorobenzophenone in step B is 1:0.01 - 1; preferably, the molar ratio of 2,6 - dichlorobenzonitrile to N - methylpyrrolidone in the N - methylpyrrolidone solution of 2,6 - dichlorobenzonitrile in step B is 1:2 - 10;

[0018] The molar ratio of hydroquinone: (2,6 - dichlorobenzonitrile + 4,4 - difluorobenzophenone) is 1:1.01 - 1.05, preferably 1:1.02;

[0019] Preferably, when the water removal in step A reaches 98% of the theoretical water removal amount, a mixed solution of 4,4 - difluorobenzophenone and 2,6 - dichlorobenzonitrile dissolved in NMP is added to the hydroquinone salt solution prepared in step A.

[0020] In a specific embodiment, the temperature of the pre - polymerization by heating in step B is 180 - 220 °C, preferably 180 - 185 °C; the pre - polymerization reaction time is 0.5 - 2 hours, preferably 1 hour; the pressure of the inert atmosphere in step B is preferably 0.1 - 1 MPa, more preferably 0.8 - 1 MPa.

[0021] In a specific embodiment, the polymerization time in step C is 1 - 4 hours, preferably 2 hours.

[0022] In a specific embodiment, the prepolymer in step C is polymerized under 1.4 - 1.5 MPa, and the polymerization temperature is preferably 250 - 255 °C.

[0023] In a specific embodiment, the mass ratio of deionized water to N-methylpyrrolidone in step D is 1:5 - 10; preferably 1:8; preferably stirred at 230 °C to obtain a polyaryletherketonenitrile slurry;

[0024] The stirring time at 220 - 240 °C in step D is 0.1 - 1 h, preferably 0.5 h.

[0025] In a specific embodiment, the method further includes filtering, washing with deionized water, and drying the polyaryletherketonenitrile slurry in sequence; the mesh aperture of the filter is 800 - 1000 meshes; the temperature of the deionized water is 90 - 95 °C, and the conductivity of the filtrate from the deionized water washing is lower than 20 μs / cm; the drying temperature is preferably 100 - 110 °C, more preferably 105 °C, and the drying time is preferably 6 h.

[0026] The second object of the present invention is to provide a highly crystalline polyaryletherketonenitrile.

[0027] To achieve the second object of the present invention, the chemical structural formula of the highly crystalline polyaryletherketonenitrile is shown as formula I below:

[0028]

[0029] The range of m is 40 - 200; the range of n is 8 - 40. The average particle size of the highly crystalline polyaryletherketonenitrile is 1200 - 1900 μm, the tensile strength is 117 - 119 MPa, the elongation at break is 21 - 26%, the flexural strength is 161 - 165 MPa, the flexural modulus is 2500 - 3500 MPa, the notched Izod impact strength is 9.6 - 10.9 kJ / cm 2 , the heat distortion temperature is 167 - 169 °C, the glass transition temperature is 181 - 184 °C, the melting temperature is 370 °C - 371 °C, the melt index is 25 - 32 g / 10 min, the initial decomposition temperature is 526 - 530 °C. Preferably, the highly crystalline polyaryletherketonenitrile is prepared by the above-mentioned preparation method of the highly crystalline polyaryletherketonenitrile.

[0030] Beneficial effects:

[0031] 1. The present invention can synthesize high molecular weight and highly crystalline polyaryletherketonenitrile without adding a dehydrating agent, avoiding the secondary separation of the dehydrating agent, and the residue of the dehydrating agent will reduce the product purity and its performance.

[0032] 2. The present invention uses an inert gas pressurization method to prepare high molecular weight and highly crystalline polyaryletherketonenitrile, avoiding the problem that the molecular weight is difficult to increase due to the crystallization and precipitation of the product during the polymerization process.

[0033] 3. The introduction of a small amount of 4,4-difluorobenzophenone monomer in the present invention can further increase the crystallinity of polyarylether nitrile and endow it with more excellent comprehensive properties.

[0034] 4. In the present invention, deionized water is used as a phase separation agent under high pressure conditions, and the obtained product is a slurry. The materials are convenient for transportation. The product has large particle size, loose pores, is easy to wash and separate, can effectively remove the salts and small molecule polymers encapsulated in the high molecular polymer, avoids the use of mechanical crushing, greatly reduces the usage amount of organic solvents in the post-treatment process, reduces costs, and avoids potential safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is the DSC curve of Comparative Example 2 and Example 4.

[0036] Figure 2 It is the XRD spectrum of Comparative Example 1 and Example 4.

[0037] Figure 3 It is the infrared spectrum of Example 4. DETAILED DESCRIPTION OF THE INVENTION

[0038] To achieve the first object of the present invention, the preparation method of the highly crystalline polyarylether ketone nitrile includes:

[0039] A. Preparation of phenolate: Under the protection of an inert gas, hydroquinone, a catalyst and N-methylpyrrolidone are mixed and then heated for a salt formation reaction, and the moisture is removed by entrainment with a flowing inert gas to obtain a hydroquinone salt solution;

[0040] B. Prepolymerization: Add an N-methylpyrrolidone solution of 4,4-difluorobenzophenone and 2,6-dichlorobenzonitrile to the hydroquinone salt solution described in step A, and heat and prepolymerize in an inert atmosphere of 0.1 - 2.0 MPa to obtain a prepolymer;

[0041] C. Temperature-raising polymerization: Polymerize the prepolymer described in step B at 1 - 2 MPa and 240 - 260 °C to obtain a high molecular weight crystalline polyarylether ketone nitrile polymer solution;

[0042] D. Phase separation: Pump deionized water into the polymerization solution at a high pressure of 2 - 2.5 MPa for phase separation, and then stir at 220 - 240 °C to obtain a polyarylether ketone nitrile slurry.

[0043] When the moisture in the fraction reaches 98% of the theoretical water removal amount, add a mixed solution of 4,4-difluorobenzophenone and 2,6-dichlorobenzonitrile dissolved in NMP to the hydroquinone salt solution prepared in step A.

[0044] In a specific embodiment, the temperature of the salt-forming reaction in step A is 140 - 150 °C, preferably 140 - 145 °C, the reaction time is 2 - 4 hours, preferably 3 h; preferably, the flow rate of the flowing inert gas in step A is 0.5 - 4 m 3 / h, more preferably 2 m 3 / h.

[0045] In a specific embodiment, the molar ratio of hydroquinone, catalyst and N-methylpyrrolidone in step A is 1:1 - 1.5:5 - 20; preferably 1:1.2:5 - 20.

[0046] In a specific embodiment, the catalyst in step A includes one of potassium carbonate, sodium carbonate, potassium bicarbonate, sodium bicarbonate, sodium hydroxide, potassium hydroxide, preferably potassium carbonate.

[0047] In a specific embodiment, the molar ratio of 2,6-dichlorobenzonitrile to 4,4-difluorobenzophenone in step B is 1:0.01 - 1; preferably, the molar ratio of 2,6-dichlorobenzonitrile to N-methylpyrrolidone in the N-methylpyrrolidone solution of 2,6-dichlorobenzonitrile in step B is 1:2 - 10;

[0048] The molar ratio of hydroquinone:2,6-dichlorobenzonitrile + 4,4-difluorobenzophenone is 1:1.01 - 1.05, preferably 1:1.02.

[0049] In a specific embodiment, the temperature of the pre-polymerization by heating in step B is 180 - 220 °C, preferably 180 - 185 °C; the pre-polymerization reaction time is 0.5 - 2 hours, preferably 1 hour; the pressure of the inert atmosphere in step B is preferably 0.1 - 1 MPa, more preferably 0.8 - 1 MPa.

[0050] In a specific embodiment, the polymerization time in step C is 1 - 4 hours, preferably 2 hours.

[0051] In a specific embodiment, the pre-polymer in step C is polymerized at 1.4 - 1.5 MPa, and the polymerization temperature is preferably 250 - 255 °C.

[0052] In a specific embodiment, the mass ratio of deionized water to N-methylpyrrolidone in step D is 1:5 - 10; preferably 1:8; preferably, a polyaryletherketonenitrile slurry is obtained by stirring at 230 °C;

[0053] The stirring time at 220 - 240 °C in step D is 0.1 - 1 h, preferably 0.5 h.

[0054] In a specific embodiment, the method further includes filtering, washing with deionized water, and drying the polyaryletherketonenitrile slurry in sequence; the aperture of the filter screen is 800 to 1000 mesh; the temperature of the deionized water is 90 to 95 °C, and the conductivity of the filtrate from the deionized water washing is lower than 20 μs / cm; the drying temperature is preferably 100 to 110 °C, more preferably 105 °C, and the drying time is preferably 6 h.

[0055] To achieve the second object of the present invention, the chemical structural formula of the highly crystalline polyaryletherketonenitrile is shown in Formula I below:

[0056]

[0057] The range of m is 40 to 200; the range of n is 8 to 40. The average particle size of the highly crystalline polyaryletherketonenitrile is 1200 to 1900 μm, the tensile strength is 117 to 119 MPa, the elongation at break is 21 to 26%, the flexural strength is 161 to 165 MPa, the flexural modulus is 2500 to 3500 MPa, the notched Izod impact strength is 9.6 to 10.9 kJ / cm 2 , the heat distortion temperature is 167 to 169 °C, the glass transition temperature is 181 to 184 °C, the melting temperature is 370 °C to 371 °C, the melt index is 25 to 32 g / 10 min, and the initial decomposition temperature is 526 to 530 °C. Preferably, the highly crystalline polyaryletherketonenitrile is prepared by using the above-mentioned preparation method of the highly crystalline polyaryletherketonenitrile.

[0058] The following further describes the specific embodiments of the present invention in conjunction with examples, and the present invention is not limited to the scope of the described examples.

[0059] Comparative Example 1

[0060] A sample of Victrex (grade: VICTREX PEEK-450G) from Victrex, UK was used as Comparative Example 1.

[0061] Comparative Example 2

[0062] First, N 2 was introduced from the bottom of the reaction kettle to ensure that the reaction kettle was in an N 2 atmosphere. Subsequently, 990 g (9 mol) of hydroquinone, 1490 g (10.8 mol) of potassium carbonate, and 3200 g of N-methylpyrrolidone (NMP) were added to the reaction kettle and heated to 140 °C for a salt-forming reaction for 3 h. Through N 2The water generated during the salification process is carried away in an entrainment manner. When the water content in the distillate tested by a Karl Fischer moisture analyzer is greater than 98% of the theoretical water removal amount, the reaction in the first stage ends, and a hydroquinone salt solution is obtained. Then, a homogeneous solution of 1579 g (9.18 mol) of 2,6-dichlorobenzonitrile dissolved in 3200 g of NMP is pumped into the reaction kettle. Subsequently, a prepolymerization reaction is carried out at a pressure of 0.8 MPa and a temperature of 185 °C for 1 h. Then, the internal temperature of the reaction kettle is raised to 250 °C, and the pressure is raised to 1.4 MPa for a polymerization reaction for 2 h. Finally, 800 g of deionized water is pumped into the reaction kettle through a high-pressure pump, the temperature is lowered to 230 °C and held for 0.5 h, and then the material is discharged when the temperature is lowered below 100 °C. It is filtered through a device with a filter screen aperture of 1000 meshes, washed with deionized water until the conductivity of the filtrate is lower than 20 μs / cm, and then vacuum dried at 105 °C for 6 h to obtain high-crystalline polyarylether nitrile powder granules, and their properties are shown in Table 1 in detail.

[0063] Example 1

[0064] First, N 2 is introduced from the bottom of the reaction kettle to ensure that the reaction kettle is in an N 2 atmosphere. Subsequently, 990 g (9 mol) of hydroquinone, 1490 g (10.8 mol) of potassium carbonate, and 3200 g of NMP are added to the reaction kettle and heated to 140 °C for a salification reaction for 3 h. The water generated during the salification process is carried away in an entrainment manner at a flow rate of 2 m 3 / h of N 2 When the water content in the distillate tested by a Karl Fischer moisture analyzer is greater than 98% of the theoretical water removal amount, the reaction in the first stage ends, and a hydroquinone salt solution is obtained. Then, a homogeneous solution of 1502 g (8.73 mol) of 2,6-dichlorobenzonitrile and 99 g (0.45 mol) of 4,4-difluorobenzophenone dissolved in 3200 g of NMP is pumped into the reaction kettle. Subsequently, a prepolymerization reaction is carried out at a pressure of 0.8 MPa and a temperature of 185 °C for 1 h. Then, the internal temperature of the reaction kettle is raised to 250 °C, and the pressure is raised to 1.4 MPa for a polymerization reaction for 2 h. Finally, 800 g of deionized water is pumped into the reaction kettle through a high-pressure pump, the temperature is lowered to 230 °C and held for 0.5 h, and then the material is discharged when the temperature is lowered below 100 °C. It is filtered through a device with a filter screen aperture of 1000 meshes, washed with deionized water until the conductivity of the filtrate is lower than 20 μs / cm, and then vacuum dried at 105 °C for 6 h to obtain high-crystalline polyarylether ketone nitrile powder granules, and their properties are shown in Table 1 in detail.

[0065] Example 2

[0066] First, N 2 is introduced from the bottom of the reaction kettle to ensure that the reaction kettle is in an N 2The atmosphere was then adjusted, and 990 g (9 mol) of hydroquinone, 1490 g (10.8 mol) of potassium carbonate, and 3200 g of NMP were added to the reaction kettle. The temperature was raised to 140 °C for a salification reaction for 3 h. Water generated during the salification process was removed by N 3 entrainment at a flow rate of 2 m 2 / h. When the water content in the distillate was greater than 98% of the theoretical water removal amount as measured by a Karl Fischer moisture analyzer, the reaction in the first stage was terminated, and a hydroquinone salt solution was obtained. Subsequently, a homogeneous solution of 1424 g (8.28 mol) of 2,6-dichlorobenzonitrile and 198 g (0.9 mol) of 4,4-difluorobenzophenone dissolved in 3200 g of NMP was pumped into the reaction kettle. Subsequently, a prepolymerization reaction was carried out at 0.8 MPa pressure and 185 °C for 1 h. Subsequently, the internal temperature of the reaction kettle was raised to 250 °C, and the pressure was raised to 1.4 MPa for a polymerization reaction for 2 h. Finally, 800 g of deionized water was pumped into the reaction kettle through a high-pressure pump, the temperature was lowered to 230 °C and maintained for 0.5 h, and then the material was discharged after the temperature was lowered below 100 °C. It was filtered through a device with a filter screen aperture of 1000 mesh and washed with deionized water until the conductivity of the filtrate was lower than 20 μs / cm. Then, it was vacuum dried at 105 °C for 6 h to obtain high-crystalline polyaryletherketonenitrile powder particles. Their properties are shown in Table 1.

[0067] Example 3

[0068] First, N 2 was introduced from the bottom of the reaction kettle to ensure that the reaction kettle was in an N 2 atmosphere. Then, 990 g (9 mol) of hydroquinone, 1490 g (10.8 mol) of potassium carbonate, and 3200 g of NMP were added to the reaction kettle. The temperature was raised to 140 °C for a salification reaction for 3 h. Water generated during the salification process was removed by N 3 entrainment at a flow rate of 2 m 2 / h. When the water content in the distillate was greater than 98% of the theoretical water removal amount as measured by a Karl Fischer moisture analyzer, the reaction in the first stage was terminated, and a hydroquinone salt solution was obtained. Subsequently, a homogeneous solution of 1347 g (7.83 mol) of 2,6-dichlorobenzonitrile and 297 g (1.35 mol) of 4,4-difluorobenzophenone dissolved in 3200 g of NMP was pumped into the reaction kettle. Subsequently, a prepolymerization reaction was carried out at 0.8 MPa pressure and 185 °C for 1 h. Subsequently, the internal temperature of the reaction kettle was raised to 250 °C, and the pressure was raised to 1.4 MPa for a polymerization reaction for 2 h. Finally, 800 g of deionized water was pumped into the reaction kettle through a high-pressure pump, the temperature was lowered to 230 °C and maintained for 0.5 h, and then the material was discharged after the temperature was lowered below 100 °C. It was filtered through a device with a filter screen aperture of 1000 mesh and washed with deionized water until the conductivity of the filtrate was lower than 20 μs / cm. Then, it was vacuum dried at 105 °C for 6 h to obtain high-crystalline polyaryletherketonenitrile powder particles. Their properties are shown in Table 1.

[0069] Example 4

[0070] First, introduce N 2 from the bottom of the reactor to ensure that the reactor is in an N 2 atmosphere. Subsequently, add 990 g (9 mol) of hydroquinone, 1490 g (10.8 mol) of potassium carbonate, and 3200 g of NMP into the reactor, heat up to 140 °C, and carry out the salification reaction for 3 h. Remove the water generated during the salification process by entrainment with N 3 at a flow rate of 2 m 2 / h. When the water content in the distillate measured by a Karl Fischer moisture analyzer is greater than 98% of the theoretical water removal amount, end the reaction in the first stage to obtain a hydroquinone salt solution. Then, pump a homogeneous solution of 1269 g (7.38 mol) of 2,6-dichlorobenzonitrile and 396 g (1.8 mol) of 4,4-difluorobenzophenone dissolved in 3200 g of NMP into the reactor. Subsequently, carry out a prepolymerization reaction at 0.8 MPa pressure and 185 °C for 1 h. Then, raise the internal temperature of the reactor to 250 °C and the pressure to 1.4 MPa to carry out a polymerization reaction for 2 h. Finally, pump 800 g of deionized water into the reactor through a high-pressure pump, cool down to 230 °C and hold for 0.5 h, cool down to below 100 °C and discharge the material. Filter through a device with a filter screen aperture of 1000 meshes, wash with deionized water until the conductivity of the filtrate is lower than 20 μs / cm, and then vacuum dry at 105 °C for 6 h to obtain high-crystalline polyaryletherketonenitrile powder particles. The performance details are shown in Table 1.

[0071] The test standards and conditions for the samples of Examples 1-4 and Comparative Examples 1-2 are as follows:

[0072] (1) Detect the average particle size of the sample based on GBT 15445.2-2006 "Expression of Particle Size Analysis Results - Part 2: Calculation of Average Particle Size / Diameter and Moments from Particle Size Distribution".

[0073] (2) Use a differential scanning calorimeter (DSC) to test the glass transition temperature (T g ) and melting point (T m ) of the sample, with a heating rate of 10 °C / min.

[0074] (3) The Fourier transform infrared spectrum is tested using a Shimadzu 8000S Fourier transform infrared spectrometer, and the wavenumber test range is 450-4000 cm -1 .

[0075] (4) Use an X'Pert PRO Alpha-1 X-ray diffractometer, with a copper target and Cu-Kα radiation to detect the crystallization of the sample, and the scanning range is 2θ = 10-80°.

[0076] (5) Measure the melt mass flow rate of the sample at 400 °C under the condition of a 2.16 kg weight based on GBT 3682-2000 "Melt Mass-Flow Rate".

[0077] (6) Measure the heat distortion temperature of the sample based on the standard of GBT 1634.1-2004 "Plastics - Determination of Vicat softening temperature - Part 1: General test method".

[0078] (7) Test the tensile properties of the sample based on the standard of GB / T1040.2-2006; test the flexural properties of plastics based on the standard of GB / T 9341-2008; determine the notched impact properties of the sample based on GB-T1043.1-2008.

[0079] Test results:

[0080] See Figure 1 for the DSC curves of Comparative Example 2 and Example 4; see Figure 2 for the XRD patterns of Comparative Example 1 and Example 4; see Figure 3 .

[0081] The statistical results of the performance test of the samples of Comparative Examples 1-2 and Examples 1-4 are shown in Table 1.

[0082] Table 1

[0083]

Claims

1. A method for preparing a highly crystalline polyaryletherketonenitrile, characterized in that: The preparation method of the highly crystalline polyaryletherketonenitrile comprises: A. Preparation of phenol salt: Under the protection of inert gas, hydroquinone, catalyst and N-methylpyrrolidone are mixed and then heated to perform salt-forming reaction, and water is removed by entrainment of flowing inert gas to obtain a hydroquinone salt solution; B. Prepolymerization: Add the N-methylpyrrolidone solution of 4,4-difluorobenzophenone and 2,6-dichlorobenzonitrile to the hydroquinone salt solution in step A, and heat and prepolymerize in an inert atmosphere of 0.1 to 2.0 MPa to obtain a prepolymer; C. Heating polymerization: polymerizing the prepolymer described in step B at 1-2 MPa and 240-260° C. to obtain a high molecular weight crystalline polyaryletherketonenitrile polymer solution; D. Phase separation: Deionized water is pumped into the polymerization solution at a high pressure of 2-2.5 MPa to perform phase separation, and then stirred at 220-240° C. to obtain a polyaryletherketonenitrile slurry.

2. The method for preparing highly crystalline polyaryletherketonenitrile according to claim 1, characterized in that: The temperature of the salt-forming reaction in step A is 140-150°C, preferably 140-145°C, and the reaction time is 2-4 hours, preferably 3 hours; preferably, the flow rate of the flowing inert gas in step A is 0.5-4 m / s. 3 / h, more preferably 2m 3 / h.

3. The method for preparing a highly crystalline polyaryletherketonenitrile according to claim 1 or 2, characterized in that: The molar ratio of hydroquinone, catalyst and N-methylpyrrolidone in step A is 1:1-1.5:5-20, preferably 1:1.2:5-20.

4. The method for preparing a highly crystalline polyaryletherketonenitrile according to claim 1 or 2, characterized in that: The catalyst in step A comprises one of potassium carbonate, sodium carbonate, potassium bicarbonate, sodium bicarbonate, sodium hydroxide and potassium hydroxide, preferably potassium carbonate.

5. The method for preparing highly crystalline polyaryletherketonenitrile according to claim 1 or 2, characterized in that: The molar ratio of 2,6-dichlorobenzonitrile to 4,4-difluorobenzophenone in step B is 1:0.01-1; preferably, the molar ratio of 2,6-dichlorobenzonitrile to N-methylpyrrolidone in the N-methylpyrrolidone solution of 2,6-dichlorobenzonitrile in step B is 1:2-10; The molar ratio of hydroquinone: 2,6-dichlorobenzonitrile + 4,4-difluorobenzophenone is 1:1.01-1.05, preferably 1:1.02; Preferably, when the water removal in step A reaches 98% of the theoretical water removal amount, a mixed solution of 4,4-difluorobenzophenone and 2,6-dichlorobenzonitrile dissolved in NMP is added to the hydroquinone salt solution prepared in step A.

6. The method for preparing highly crystalline polyaryletherketonenitrile according to claim 1 or 2, characterized in that: The temperature of the heating prepolymerization in step B is 180-220° C., preferably 180-185° C.; the reaction time of the prepolymerization is 0.5-2 hours, preferably 1 hour; the pressure of the inert atmosphere in step B is preferably 0.1-1 MPa, more preferably 0.8-1 MPa.

7. The method for preparing a highly crystalline polyaryletherketonenitrile according to claim 1 or 2, characterized in that: The polymerization time in step C is 1 to 4 hours, preferably 2 hours; Preferably, the prepolymer in step C is polymerized at 1.4-1.5 MPa, and the polymerization temperature is preferably 250-255°C.

8. The method for preparing highly crystalline polyaryletherketonenitrile according to claim 1 or 2, characterized in that: In step D, the mass ratio of deionized water to N-methylpyrrolidone is 1:5-10; preferably 1:8; preferably stirring at 230° C. to obtain a polyaryletherketonenitrile slurry; The stirring time at 220-240° C. in step D is 0.1-1 h, preferably 0.5 h.

9. The method for preparing highly crystalline polyaryletherketonenitrile according to claim 1 or 2, characterized in that: The method further comprises filtering, washing with deionized water and drying the polyaryletherketonenitrile slurry in sequence; the mesh size of the filtration is 800 to 1000 mesh; the temperature of the deionized water is 90 to 95° C., and the conductivity of the filtrate after the deionized washing is lower than 20 μs / cm; the drying temperature is preferably 100 to 110° C., more preferably 105° C., and the drying time is preferably 6 hours.

10. Highly crystalline polyaryletherketonenitrile, characterized in that: The chemical structural formula of the highly crystalline poly(aryletherketonenitrile) is shown in the following formula I: The range of m is 40 to 200; the range of n is 8 to 40. The average particle size of the high-crystalline polyaryletherketonenitrile is 1200 to 1900 μm, the tensile strength is 117 to 119 MPa, the elongation at break is 21 to 26%, the flexural strength is 161 to 165 MPa, the flexural modulus is 2500 to 3500 MPa, and the simply supported beam notched impact strength is 9.6 to 10.9 kJ / cm 2 , heat deformation temperature 167-169°C, glass transition temperature 181-184°C, melting temperature 370-371°C, melt index 25-32 g / 10min, initial decomposition temperature 526-530°C, preferably, the high crystalline polyaryletherketonenitrile is prepared by the preparation method of the high crystalline polyaryletherketonenitrile according to any one of claims 1 to 9.

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