A method for preparing a modified polyether sulfone / polyether imide polymer alloy

Abstract

The application belongs to the field of high dielectric constant (ε r ), low dielectric loss (tan delta) composite dielectric material, and particularly relates to a preparation method of a modified polyether sulfone / polyether imide polymer alloy. g Polymer polyether imide is blended, the mixture is added into DMAc at a solid content of 15%-20%, is stirred and dissolved at 80 DEG C, then a thin film is prepared on a glass plate by using a scraping coating method, finally the glass plate is transferred to a vacuum oven, is kept at 55 DEG C overnight, is kept at 100 DEG C for 3-5 hours, and is cured at 180 DEG C for 3-5 hours, thereby a blended film is prepared, wherein the mass fraction of the modified polyether sulfone in the mixture is 1wt%-30wt%. The modified polyaryl ether sulfone polymer segment with a side chain branched large dipole moment polar group is used as an organic filler, a small amount of addition can greatly reduce the dielectric loss, the operation is simple, the spectrum is good, and the influence on T g is very small, and the dispersion and interface problems of inorganic fillers are avoided.

Description

Technical Field

[0001] This invention belongs to the category of high dielectric constant (ε) r In the field of low dielectric loss (tanδ) composite dielectric materials, specifically involving a method for preparing a modified polyethersulfone / polyetherimide polymer alloy. Background Technology

[0002] Polymer-based dielectric energy storage capacitors have been widely used in modern electronic and power systems due to their advantages such as fast charging and discharging speeds and high power density. Especially in recent years, with the rise of polymer-based dielectric energy storage capacitors in new energy vehicles, wind turbines, and downhole oil and gas exploration, higher requirements have been placed on the high-temperature energy storage performance of dielectric energy storage capacitors, such as operating temperatures up to 150℃. Currently, the mainstream biaxially oriented polypropylene (BOPP, continuous operating temperature <85℃) based dielectric energy storage capacitors are gradually failing to meet the performance requirements of these new fields. Therefore, the development of high dielectric constant (ε) capacitors is crucial. r High operating temperature and low dielectric loss (tanδ) dielectric polymers are currently an important research direction.

[0003] Polymer-based nanocomposites have been extensively studied for their dielectric properties enhanced by the addition of fillers, as they combine the advantages of high dielectric constant of ceramics and low loss of polymers. However, due to the surface energy difference between inorganic ceramics and polymer matrices, the problems of poor dispersion and compatibility of ceramic fillers in the matrix have always been difficult to solve effectively in industry, especially at high temperatures, where their dielectric energy storage performance deteriorates rapidly. Moreover, the addition of inorganic fillers inevitably weakens the processability of the polymer matrix. Excessive fillers can lead to poor film flexibility, brittle texture, and reduced processability and reliability.

[0004] To avoid the above problems, molecular engineering can be used to directly apply high-T... g (Glass transition temperature) Introducing highly polar groups into the polymer molecular chain. However, in methods that introduce highly polar groups into the molecular branches, the introduction of polar groups can cause the matrix T... g The dielectric loss of the thin film is reduced, and the influence of steric hindrance on dipole polarization still inevitably increases the dielectric loss of the thin film, and the industrial production cost is high. Summary of the Invention

[0005] To address the issue that existing methods of introducing large polar groups into molecular branches can cause the matrix T... g To address the problems of high dielectric loss and high industrial production costs of dielectric polymers, this invention provides a method for preparing modified polyethersulfone.

[0006] The preparation method of this modified polyethersulfone includes the following steps:

[0007] A solvent, dehydrating agent, alkali, a mixture of difluoromonomers, and dihydroxymonomers are added to a reactor and reacted at 140°C for 3-4 hours. After removing water, the mixture is kept at 160°C-165°C for 3-4 hours to obtain a dark brown viscous liquid. This dark brown viscous liquid is poured into acid, allowed to stand, filtered, and dried to obtain a pale yellow solid. The pale yellow solid is pulverized and boiled in boiling water for 1 hour, repeated 3-5 times. Washing is performed until pH = 7, and the modified polyethersulfone is obtained after drying.

[0008] The difluoro monomer mixture includes difluoro monomers containing sulfonyl fluoride chains and difluoro monomers without sulfonyl fluoride chains.

[0009] Furthermore, the mass ratio of the solvent to the dehydrating agent is 5:1;

[0010] The molar ratio of the difluoro monomer mixture, the dihydroxy monomer, and the base is 1:1:1.2;

[0011] The difluoro monomer containing a sulfonyl fluorine chain accounts for 2%-60% of the molar ratio in the difluoro monomer mixture.

[0012] Furthermore, the solvent is selected from N,N-dimethylacetamide;

[0013] The dehydrating agent is selected from toluene;

[0014] The alkali is selected from anhydrous potassium carbonate;

[0015] The difluoro monomer without a sulfonyl fluorine chain is selected from one or more of 4,4'-difluorodiphenyl sulfone, 1,3-difluorobenzene, 1,4-difluorobenzene, 4,4'-difluorodiphenylmethane, and 4,4'-difluorodiphenyl ether.

[0016] The dihydroxy monomer is selected from one or more of 4,4'-dihydroxydiphenyl sulfone, bisphenol A, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenylmethane, 2,5-dihydroxytoluene, 2,7-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxyfluorene, 1,4-dihydroxybenzene, and 1,4-bis(3-hydroxyphenoxy)benzene.

[0017] Furthermore, the difluoro monomer containing a sulfonyl fluorine chain in the preparation method of the modified polyethersulfone is prepared by the following method:

[0018] The amino group of 3,5-difluorobenzylamine, the sulfonyl group of the fluorinated grafting agent, and triethylamine were added to dichloromethane in a molar ratio of 1:1:2.5, and the solid content of the mixture was 25%-30%.

[0019] Furthermore, the sulfonyl-containing fluorinated grafting agent is selected from 1,1,2,2,3,3,4,4,5,5,6,6,6-trifluorotrifluoro-1-hexanesulfonyl fluoride, perfluorooctanesulfonyl chloride, pentafluorobenzenesulfonyl chloride, trifluoromethanesulfonyl chloride, etc.

[0020] One or more of the following: 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-pentadecylfluoroheptane-1-sulfonyl fluoride, perfluorooctyl sulfonyl fluoride, perfluoro-1-butane sulfonyl fluoride, and trifluoromethyl sulfonyl fluoride.

[0021] The present invention also provides a modified polyethersulfone.

[0022] The modified polyethersulfone is obtained by the preparation method of the modified polyethersulfone as described in any of the preceding claims.

[0023] Furthermore, the modified polyethersulfone has the following general structural formula:

[0024]

[0025] Wherein, R1 is selected from One or more of them.

[0026] R2 is selected from One or more of them.

[0027] R3 is selected from one or more of perfluorinated substituted alkyl or perfluorinated substituted aryl;

[0028] a and b are selected from any positive integers.

[0029] This invention also provides a method for preparing a modified polyethersulfone / polyetherimide polymer alloy.

[0030] The preparation method of this modified polyethersulfone / polyetherimide polymer alloy includes the following steps:

[0031] The modified polyethersulfone described above and high T g (210-225℃) Polymer polyetherimide blend: The mixture is added to DMAc at a solid content of 15%-20%, stirred and dissolved at 80℃, and then coated onto a glass plate to form a thin film. Finally, the glass plate is transferred to a vacuum oven, incubated overnight at 55℃, held at 100℃ for 3-5 hours, and cured at 180℃ for 3-5 hours to obtain the blended film.

[0032] The modified polyethersulfone has a mass fraction of 1 wt% to 30 wt% in the mixture.

[0033] Furthermore, the modified polyethersulfone has a mass fraction of 2wt%-4wt% in the mixture.

[0034] Beneficial effects:

[0035] 1. The preparation of difluoro monomers containing sulfonyl fluorine chains can be completed at room temperature.

[0036] 2. Modified polyethersulfone can achieve significant effects at low addition levels, thus exhibiting good dispersibility and minimal impact on the mechanical properties and Tg of the film, thereby maximizing the preservation of the superior performance of the substrate material at high temperatures.

[0037] 3. Modified polyethersulfone can be regarded as a polymer modifier with good industrial compatibility, broad spectrum, simple operation, and high application potential. Compared with direct grafting modification on the matrix polymer molecular chain, the production cost is greatly reduced.

[0038] 4. By constructing polar nanoregions with large dipole moments through the self-assembly of perfluoroalkyl chains, the problem of dielectric materials with large dipole moment groups was solved. r The contradiction between tanδ and ε is realized in improving the composite material's ε r At the same time, it aims to reduce its tanδ. Attached Figure Description

[0039] Figure 1 The 1H NMR spectrum of the difluoro monomer containing a sulfonyl fluorine chain provided in Example 1 (deuterated reagent: deuterated dimethyl sulfoxide (DMSO-d6));

[0040] Figure 2 Fluorine spectrum of the difluoro monomer containing a sulfonyl fluorine chain provided in Example 1 (deuterated reagent: deuterated dimethyl sulfoxide (DMSO-d6));

[0041] Figure 3 Carbon 160-carbon spectrum of the difluoro monomer containing a sulfonyl fluorine chain provided in Example 1 (deuterated reagent: deuterated dimethyl sulfoxide (DMSO-d6));

[0042] Figure 4 High-resolution mass spectrometry (negative mode, hydrogen reduction) of the difluoro monomer containing a sulfonyl fluorine chain provided in Example 1;

[0043] Figure 5 Fluorine spectrum of the modified polyarylene ether sulfone provided in Example 1 (deuterated reagent: deuterated dimethyl sulfoxide (DMSO-d6)). Detailed Implementation

[0044] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but this should not be construed as limiting the scope of the present invention.

[0045] This invention aims to directly utilize molecular engineering in high-T... g(Glass transition temperature 210℃-225℃) Introducing large dipole moment polar groups into the polymer molecular chain solves the problems of poor compatibility, low processability, poor reliability, and high production cost of existing dielectric polymers. The sub-T of the polar groups... g Relaxation can also achieve the goal of increasing the dielectric constant of polymers, while avoiding a series of problems caused by the introduction of inorganic fillers. When combined with polymer alloy technology, the advantages of various polymer materials can be combined, which is more conducive to reducing production costs, expanding the scope of application, and lowering the threshold for industrialization. Therefore, it has broad application prospects.

[0046] The basic principle of this invention is as follows: A novel polyarylene ether sulfone (PES) modified polymer is synthesized through molecular structure design. A fluorinated grafting agent with large dipole moment polar groups (-SO2) is grafted onto the molecular side. This grafting agent is then blended with a polyetherimide (PEI) polymer with excellent high-temperature performance. Fluorine nanoregions containing polar groups are constructed by utilizing the difference in surface energy between the fluorinated segments and the main chain. The controllable distribution of these polar group-containing nanoregions is achieved using a "fluorine migration" method. This improves the bandgap of the polymer dielectric film and optimizes its high-temperature dielectric energy storage performance. The molecular structure design method avoids the dispersion and interface problems associated with inorganic fillers. Fluorine, being a large atom, leads to an increase in the free volume within the microregions, and the polar groups sub-T g The reduction in polarization resistance achieves the goal of increasing the dielectric constant while decreasing dielectric loss. Simultaneously, using modified polyarylene ether sulfone (PES-F) polymer fragments with side-linked large dipole moment polar groups as an organic filler, even small amounts can significantly reduce dielectric loss. This method is simple to operate, has broad applicability, and also improves T... g The impact is minimal.

[0047] This invention provides a modified polyarylene ether sulfone.

[0048] Under alkaline conditions, the modified polyarylene ether sulfone (PES-F) is formed by nucleophilic substitution polymerization of a mixture of dihydroxy monomers (HO-R1-OH) and difluoro monomers (FBA-F and F-R2-F), introducing fluorinated side chains. The reaction flow is shown in the figure below:

[0049]

[0050] The preparation method of modified polyarylene ether sulfone includes the following steps:

[0051] First, N,N-dimethylacetamide (DMAc) was added to a three-necked flask at a solid content of 25%-30%. Simultaneously, toluene was added at a mass ratio of DMAc:toluene = 5:1. Finally, the mixture of difluoromonomers (FBA-F and F-R2-F):dihydroxymonomers:anhydrous potassium carbonate was added at a molar ratio of 1:1:1.2. The reaction apparatus was set up, and the mixture was stirred while being purged with nitrogen for 20 minutes. The temperature was then raised to 140℃ and reacted for 3-4 hours, using toluene to remove the water produced during the reaction. This stage is crucial for increasing the molecular weight of the product; the molecular weight increases with the duration of the reaction. Second, the temperature was raised to 160-165℃ and maintained for 3-4 hours to obtain a dark brown viscous liquid. While still hot, this liquid was slowly poured into dilute hydrochloric acid and allowed to stand overnight. After filtration, washing, and drying, a pale yellow solid was obtained. Finally, the product was pulverized and boiled in boiling water for 1 hour, repeated 3-5 times. Washing was continued until the pH reached 7, and the product was dried to obtain PES-F powder.

[0052] The molar ratio (b / (a+b)) of the difluoro monomer containing sulfonyl fluorine chain in the difluoro monomer mixture is 2%-60%, preferably 30%-40%, where a and b are the number of repeating structural units, which are any positive integers, and the molecular weight of the modified polyarylether sulfone is between 6000 and 50000.

[0053] The dihydroxy monomer (HO-R1-OH) is selected from one or more of 4,4'-dihydroxydiphenyl sulfone, bisphenol A, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenylmethane, 2,5-dihydroxytoluene, 2,7-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxyfluorene, 1,4-dihydroxybenzene, and 1,4-bis(3-hydroxyphenoxy)benzene.

[0054] The difluoro monomer (F-R2-F) without a sulfonyl fluorine chain is selected from one or more of 4,4'-difluorodiphenyl sulfone, 1,3-difluorobenzene, 1,4-difluorobenzene, 4,4'-difluorodiphenylmethane and 4,4'-difluorodiphenyl ether.

[0055] The synthesis route for the difluoro monomer containing a sulfonyl group (FBA-F) involves covalently grafting a sulfonyl fluorine chain onto 3,5-difluorobenzylamine (3,5-DFBA) using a typical aminosulfonation reaction (also known as the Hinsberg reaction). The synthetic route is shown in the figure below.

[0056]

[0057] The method for synthesizing difluoro monomers containing sulfonyl fluorine chains (FBA-F) includes the following steps:

[0058] First, calculate the required amount of dichloromethane solvent based on the solid content (25%-30%), and add it according to the molar ratio of amino group of 3,5-difluorobenzylamine: sulfonyl group of sulfonyl-containing fluorinated grafting agent: triethylamine = 1:1:2.5. Then, stir the reaction at room temperature for 1-4 days. Afterward, pour the liquid phase into the prepared treatment solution (a mixture with a volume ratio of diethyl ether:water:ice:85% H3PO4 = 75:50:25:2) and shake it several times. Extract the aqueous phase three times with diethyl ether and combine the organic phases. Next, wash the organic phase successively with deionized water and saturated sodium chloride, dry with anhydrous magnesium sulfate, remove the solvent by rotary evaporation, and finally vacuum dry at 60-70℃ for 10-15 h to obtain pure difluoro monomers containing sulfonyl fluorine chains (FBA-F).

[0059] The sulfonyl-containing fluorinated grafting agent is selected from one or more of 1,1,2,2,3,3,4,4,5,5,6,6,6-trifluorotrifluoro-1-hexanesulfonyl fluoride, perfluorooctanesulfonyl chloride, pentafluorobenzenesulfonyl chloride, trifluoromethanesulfonyl chloride, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-pentadecafluoroheptane-1-sulfonyl fluoride, perfluorooctylsulfonyl fluoride, perfluoro-1-butanesulfonyl fluoride, and trifluoromethylsulfonyl fluoride.

[0060] This invention also provides a method for preparing a modified polyarylene ether sulfone / polyether imide polymer alloy. The method for preparing the modified polyarylene ether sulfone / polyether imide polymer alloy includes the following steps:

[0061] The modified polyarylene ether sulfone (PES-F) synthesized above was mixed with high-T in a certain proportion. g Polymer polyetherimide blends are prepared by adding the mixture to DMAc at a solid content of 15%-20% and stirring to dissolve at 80°C. The resulting film is then coated onto a glass plate using a blade coating method. The glass plate is then transferred to a vacuum oven and cured overnight at 55°C, followed by 3-5 hours at 100°C, and finally 3-5 hours at 180°C to obtain the blended film.

[0062] The mass fraction of PF in the blend is 1 wt%-30 wt%, more preferably 2 wt%-4 wt%.

[0063] Examples 1-7 are provided according to the preparation method described above.

[0064] Example 1

[0065] First, add 3,5-DFBA (0.01 mol), CH2Cl2 (7.2 ml), and triethanolamine (TEA, 0.025 mol) to a single-necked flask in the specified proportions. Place a magnetic stir bar in the flask, and then slowly add perfluorobutylsulfonyl fluoride (PBSF, 0.01 mol) while stirring. After purging the air in the flask with nitrogen, seal the flask and stir at room temperature for 4 days to obtain a pale yellow transparent liquid. At this point, transfer the liquid phase to a separating funnel, add diethyl ether (75 ml), water (50 ml), ice (25 g), and 85% H3PO4 (2 ml), shake several times, and allow it to stand to separate into two phases. Extract the aqueous phase three times with Et2O. Combine the organic phases, wash successively with 20 ml of deionized water and 20 ml of saturated NaCl, and then dry and filter with anhydrous magnesium sulfate. Finally, the CH2Cl2 solvent was removed by rotary evaporation, and the product was dried under vacuum at 65°C for 10 h to obtain a pale yellow solid product N-(3,5-difluorophenyl)-1,1,2,3,3,4,4-nonfluorobutane-1-sulfonamide (FBA-F).

[0066] Then, FBA-F (0.01 mol), 4,4'-difluorodiphenyl sulfone (DOD, 0.015 mol), 4,4'-dihydroxybiphenyl (FPS, 0.025 mol), DMAc (30 g), MB (5 g), and anhydrous potassium carbonate (0.03 mol) were sequentially added to a three-necked flask, and a reaction apparatus was constructed. The mixture was stirred and purged with nitrogen for 20 minutes. The temperature was then raised to 140 °C and reacted for 4 hours, removing water produced during the reaction using toluene. Next, the temperature was raised to 160-165 °C and maintained for 4 hours, yielding a dark brown viscous liquid. This liquid was then slowly poured into dilute hydrochloric acid (1 mol / L) while hot and allowed to stand overnight. After filtration, washing, and drying, a pale yellow solid was obtained. Finally, the product was pulverized and boiled in boiling water for 1 hour, repeated four times until pH = 7. After drying, PES-F powder was obtained.

[0067] PES-F (0.2 g) and PEI (9.8 g) were added to DMAc (50 g) and stirred at 80 °C until completely dissolved. After cooling, a thin film was formed on a glass plate using a doctor blade coating method. Finally, the glass plate was transferred to a vacuum oven and cured at 55 °C overnight, 100 °C for 4 hours, and 180 °C for 4 hours to obtain a 2 wt% PES-F@PEI blend film. The measured ε... r =2.95, tanδ=0.0075 (150℃, 560kHz), T g =216.9℃.

[0068] The proton, fluorine, and carbon spectra of difluoro monomers containing sulfonyl fluorine chains, as well as the fluorine spectrum of modified polyarylether sulfones, were determined. The test results are as follows: Figures 1-5 As shown:

[0069] Figure 1 The 1H NMR spectra of difluoro monomers containing sulfonyl fluorine chains are as follows: 1 H NMR (400MHz, DMSO) δ10.31 (s, 1H), 7.19 (t, J = 10.4Hz, 1H), 7.07 (d, J = 6.5Hz, 2H), 4.46 (s, 2H);

[0070] Figure 2 The fluorine spectrum results of difluoro monomers containing sulfonyl fluorine chains are as follows: 19 F NMR(376MHz,DMSO)δ-80.37(t,J=9.6Hz,3F),-109.49(t,J=8.7Hz,2F),-113.2 4(t,J=13.2Hz,2F),-121.21(dd,J=10.9,6.6Hz,2F),-125.72–-125.83(m,2F);

[0071] Figure 3 The carbon spectral results of difluorinated monomers containing sulfonyl fluorine chains are as follows: 13 C NMR (101MHz, DMSO) δ163.89,163.76,161.44,161.31,141.98,141.89,141.80,118.70,118.37,118.04,115.8 3,115.50,115.17,114.40,114.05,113.70,110.64,110.57,110.45,110.38,103.32,103.07,102.81,46.16;

[0072] Figure 5 The fluorine spectrum results of the modified polyarylene ether sulfone are as follows: 19 F NMR(376MHz, DMSO)δ-80.31(t,J=9.5Hz,3F),-109.77(t,J=8.2Hz,1F),-113.38 (t,J=13.1Hz,2F),-121.15–-121.27(m,2F),-125.75(dd,J=14.6,11.4Hz,2F).

[0073] Example 2

[0074] The PES-F (0.4 g) and PEI (9.6 g) prepared in Example 1 were added to DMAc (50 g) and stirred at 80 °C until completely dissolved. After cooling, a thin film was formed on a glass plate using a blade coating method. Finally, the glass plate was transferred to a vacuum oven and cured at 55 °C overnight, 100 °C for 4 hours, and 180 °C for 4 hours to obtain a blend film of 4 wt% PES-F@PEI. The measured ε... r=3.2, tanδ=0.001 (150℃, 560kHz), T g =214.5℃.

[0075] Example 3

[0076] The PES-F (0.6 g) and PEI (9.4 g) prepared in Example 1 were added to DMAc (50 g) and stirred at 80°C until completely dissolved. After cooling, a thin film was formed on a glass plate using a blade coating method. Finally, the glass plate was transferred to a vacuum oven and cured at 55°C overnight, 100°C for 4 hours, and 180°C for 4 hours to obtain a 6 wt% PES-F@PEI blend film. The measured ε... r =3.25, tanδ=0.004 (150℃, 560kHz), T g =209.1℃.

[0077] Example 4

[0078] The PES-F (0.8 g) and PEI (9.2 g) prepared in Example 1 were added to DMAc (50 g) and stirred at 80 °C until completely dissolved. After cooling, a thin film was formed on a glass plate using a blade coating method. Finally, the glass plate was transferred to a vacuum oven and cured at 55 °C overnight, 100 °C for 4 hours, and 180 °C for 4 hours to obtain an 8 wt% PES-F@PEI blend film. The measured ε... r =3.3, tanδ=0.004 (150℃, 560kHz), T g =209.2℃.

[0079] Example 5

[0080] The PES-F (1g) and PEI (9g) prepared in Example 1 were added to DMAc (50g) and stirred at 80°C until completely dissolved. After cooling, a thin film was formed on a glass plate using a blade coating method. Finally, the glass plate was transferred to a vacuum oven and cured at 55°C overnight, 100°C for 4 hours, and 180°C for 4 hours to obtain a 10wt% PES-F@PEI blend film. The measured ε... r =3.45, tanδ=0.004 (150℃, 560kHz), T g =200.9℃.

[0081] Example 6

[0082] The PES-F (1.2 g) and PEI (8.8 g) prepared in Example 1 were added to DMAc (50 g) and stirred at 80 °C until completely dissolved. After cooling, a thin film was formed on a glass plate using a blade coating method. Finally, the glass plate was transferred to a vacuum oven and cured at 55 °C overnight, 100 °C for 4 hours, and 180 °C for 4 hours to obtain a 12 wt% PES-F@PEI blend film. The measured ε... r =3.5, tanδ=0.0025 (150℃, 560kHz), T g =201.9℃.

[0083] Example 7

[0084] The PES-F (3g) and PEI (7g) prepared in Example 1 were added to DMAc (50g) and stirred at 80°C until completely dissolved. After cooling, a thin film was formed on a glass plate using a blade coating method. Finally, the glass plate was transferred to a vacuum oven and cured at 55°C overnight, 100°C for 4 hours, and 180°C for 4 hours to obtain a 30wt% PES-F@PEI blend film. The measured ε... r =3.5, tanδ=0.0125 (150℃, 560kHz), T g =172.8℃.

[0085] Comparative Example 1

[0086] PEI (10g) was added to DMAc (50g) and stirred at 80℃ until completely dissolved. After cooling, a thin film was formed on a glass plate using a blade coating method. Finally, the glass plate was transferred to a vacuum oven and cured at 55℃ overnight, 100℃ for 4 hours, and 180℃ for 4 hours to obtain the PEI film. The measured ε... r =2.88, tanδ=0.0055 (150℃, 560kHz), T g =227.5℃.

[0087] The modified polyarylene ether sulfone / polyetherimide composite films prepared in Examples 1-7 and Comparative Example 1 were subjected to electrical, physicochemical, and mechanical property measurements. Electrical property testing was performed according to SJ / T 1147-1993 standard, and mechanical property testing was performed according to GB / T13022-1991 standard.

[0088] Experimental results:

[0089]

[0090]

[0091] The method for preparing the modified polyethersulfone / polyetherimide polymer alloy provided by this invention constructs polar nanoregions with large dipole moments through the self-assembly of perfluoroalkyl chains, thus solving the problem of dielectric materials with large dipole moment groups. r The contradiction between tanδ and ε is realized in improving the composite material's ε r At the same time, the purpose is to reduce its tanδ.

Claims

1. A process for the preparation of a modified polyether sulfone, characterized in that, comprising the following steps: adding a solvent, a water-carrying agent, a base, a difluoromonomer mixture and a dihydroxymonomer in a reactor, reacting at 140℃ for 3-4 hours, holding at 160℃-165℃ for 3-4 hours, obtaining a dark brown viscous liquid, pouring the dark brown viscous liquid into an acid, standing, drying after filtration to obtain a light yellow solid, crushing the light yellow solid, boiling in boiling water for 1h, repeating 3-5 times, washing until PH=7, drying to obtain the modified polyether sulfone, wherein the difluoromonomer mixture comprises a difluoromonomer containing a sulfonyl fluoride chain and a difluoromonomer not containing a sulfonyl fluoride chain; the difluoromonomer containing a sulfonyl fluoride chain is prepared by the following method: a mixture of 3,5-difluorobenzylamine, a sulfonyl-containing fluorine grafting agent containing a sulfonyl fluoride chain and triethylamine is prepared according to a molar ratio of 1:1:2.5, and the solid content in the mixture is 25%-30%.

2. The preparation method of the modified polyether sulfone according to claim 1, wherein, the mass ratio of the solvent to the water-carrying agent is 5:1; the molar ratio of the difluoromonomer mixture, the dihydroxymonomer and the base is 1:1:1.2; the molar ratio of the difluoromonomer containing a sulfonyl fluoride chain in the difluoromonomer mixture is 2%-60%.

3. The preparation method of the modified polyether sulfone according to claim 1, wherein, the solvent is selected from N,N-dimethylacetamide; the water-carrying agent is selected from toluene; the base is selected from anhydrous potassium carbonate; the difluoromonomer not containing a sulfonyl fluoride chain is selected from one or more of 4,4'-difluorodiphenyl sulfone, 1,3-difluorobenzene, 1,4-difluorobenzene, 4,4'-difluorodiphenylmethane and 4,4'-difluorodiphenyl ether; the dihydroxymonomer is selected from one or more of 4,4'-dihydroxydiphenyl sulfone, bisphenol A, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl methane, 2,5-dihydroxytoluene, 2,7-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxyfluorene, 1,4-dihydroxybenzene and 1,4-bis(3-hydroxyphenoxy)benzene.

4. The preparation method of the modified polyether sulfone according to claim 1, wherein, the sulfonyl-containing fluorine grafting agent is selected from one or more of 1,1,2,2,3,3,4,4,5,5,6,6,6-trifluorotri-fluoro-1-hexane sulfonyl fluoride, perfluorooctane sulfonyl chloride, pentafluorobenzenesulfonyl chloride, trifluoromethanesulfonyl chloride, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,7-pentadecafluoroheptane-1-sulfonyl fluoride, perfluoro-octylsulfonyl fluoride, perfluoro-1-butane sulfonyl fluoride and trifluoromethylsulfonyl fluoride.

5. A modified polyether sulfone, characterized in that, obtained by the preparation method of the modified polyether sulfone according to any one of claims 1-4.

6. The modified polyether sulfone according to claim 5, wherein having the following general structure: wherein R1is selected from one or more of R2is selected from one or more of the following: R3 is selected from one or more of perfluorinated alkyl or perfluorinated aryl; a, b are selected from any positive integer.

7. A method for preparing a modified polyethersulfone / polyetherimide polymer alloy, characterized in that, comprising the following steps: The modified polyether sulfone of claim 5 is blended with high T g Polymer polyetherimide is blended, the mixture is added into DMAc with solid content of 15%-20%, stirred and dissolved at 80°C, then a film is prepared on a glass plate by using a doctor blade method, finally the glass plate is transferred into a vacuum oven, and the film is prepared after being kept at 55°C overnight, 100°C for 3-5 hours and 180°C for 3-5 hours, wherein the mass fraction of the modified polyether sulfone in the mixture is 1wt%-30wt%.

8. The method of claim 7, wherein the modified polyether sulfone / polyether imide polymer alloy is prepared by mixing the modified polyether sulfone and the polyether imide in a weight ratio of 2: 1 to 1 :

1. The modified polyether sulfone is present in the mixture in a mass fraction of 2 wt% to 4 wt%.

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