CN106589372B - Polyimide containing bipyrimidine ring and preparation method thereof - Google Patents

Polyimide containing bipyrimidine ring and preparation method thereof Download PDF

Info

Publication number
CN106589372B
CN106589372B CN201611076066.4A CN201611076066A CN106589372B CN 106589372 B CN106589372 B CN 106589372B CN 201611076066 A CN201611076066 A CN 201611076066A CN 106589372 B CN106589372 B CN 106589372B
Authority
CN
China
Prior art keywords
carrying
temperature
polyimide
solid
ona
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201611076066.4A
Other languages
Chinese (zh)
Other versions
CN106589372A (en
Inventor
侯豪情
徐海波
杨婷
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CHANGCHUN HIPOLYKING CO Ltd
Original Assignee
Jiangxi Normal University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Jiangxi Normal University filed Critical Jiangxi Normal University
Priority to CN201611076066.4A priority Critical patent/CN106589372B/en
Publication of CN106589372A publication Critical patent/CN106589372A/en
Application granted granted Critical
Publication of CN106589372B publication Critical patent/CN106589372B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
    • C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
    • C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
    • C08G73/1003—Preparatory processes
    • C08G73/1007—Preparatory processes from tetracarboxylic acids or derivatives and diamines
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D239/00—Heterocyclic compounds containing 1,3-diazine or hydrogenated 1,3-diazine rings
    • C07D239/02—Heterocyclic compounds containing 1,3-diazine or hydrogenated 1,3-diazine rings not condensed with other rings
    • C07D239/24—Heterocyclic compounds containing 1,3-diazine or hydrogenated 1,3-diazine rings not condensed with other rings having three or more double bonds between ring members or between ring members and non-ring members
    • C07D239/26—Heterocyclic compounds containing 1,3-diazine or hydrogenated 1,3-diazine rings not condensed with other rings having three or more double bonds between ring members or between ring members and non-ring members with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to ring carbon atoms
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
    • C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
    • C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
    • C08G73/1067—Wholly aromatic polyimides, i.e. having both tetracarboxylic and diamino moieties aromatically bound
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
    • C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
    • C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
    • C08G73/1067—Wholly aromatic polyimides, i.e. having both tetracarboxylic and diamino moieties aromatically bound
    • C08G73/1071—Wholly aromatic polyimides containing oxygen in the form of ether bonds in the main chain
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
    • D01F6/58—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products
    • D01F6/74—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polycondensates of cyclic compounds, e.g. polyimides, polybenzimidazoles

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Macromolecular Compounds Obtained By Forming Nitrogen-Containing Linkages In General (AREA)
  • Artificial Filaments (AREA)

Abstract

The invention discloses a polyimide containing a bipyrimidine ring, which has a structural general formula as follows:wherein n is 10-1000, Ar is at least one of the following structural units:

Description

polyimide containing bipyrimidine ring and preparation method thereof
Technical Field
The invention belongs to the technical field of high polymer materials, and particularly relates to polyimide containing a bipyrimidine ring and a preparation method thereof.
background
As a high-tech fiber, a polyimide fiber material has good chemical stability, excellent thermo-mechanical properties and outstanding irradiation resistance, and has become a hot variety for industrial development. In particular, in recent years, polyimide fiber materials have gradually moved to the aerospace field, which imposes higher requirements on heat resistance and strength.
Therefore, it is highly desirable to develop a novel polyimide fiber material having better heat resistance and higher strength than the existing materials.
disclosure of Invention
in order to solve the above problems, one aspect of the present invention provides a polyimide containing a bipyrimidine ring, which has a general structural formula:
Wherein n is 10-1000, Ar is at least one of the following structural units:
another aspect of the present invention provides a method for preparing the dipyrimidine ring-containing polyimide, comprising the following steps:
(1) to nitro radicalBenzonitrile and anhydrous methanol were placed in a dry 500ml reactor and CH was added while stirring3ONa/CH3Stirring the OH solution at room temperature for 5-10 h, and adding acetic acid to neutralize CH in the system3ONa, stirring for 30min, adding NH4cl, controlling the temperature to be 35-40 ℃, reacting for 8-20 h at the temperature, cooling to room temperature, evaporating methanol to obtain a solid, repeatedly washing the solid with acetone, and performing vacuum pumping to obtain beige solid p-nitrobenzamidine hydrochloride;
wherein the molar ratio of the p-nitrobenzonitrile to the ammonium chloride, the sodium methoxide and the acetic acid is 15: 12: 1: 1-20: 18: 3:1, the volume ratio of the organic solvent anhydrous methanol to the p-nitrobenzonitrile is 7: 1-9: 1, CH3ONa in CH3ONa/CH3The mass fraction of the OH solution is 30-65%;
(2) Placing p-phenylenediacetic acid and a polar organic solvent into a dry 500ml reactor, and slowly dripping POCl in the stirring process3controlling the temperature to be below 70 ℃ in the dripping process, controlling the temperature to be 65-70 ℃ after dripping is finished, reacting for 1-5 h, and cooling to room temperature;
Wherein the p-phenylenediacetic acid and POCl3in a molar ratio of 1: 3-1: 5; the volume ratio of the organic solvent with high polarity to the p-phenylenediacetic acid is 10: 1-15: 1;
(3) placing sodium hydroxide and distilled water in a dry 500ml reactor, mechanically stirring in a low-temperature reaction bath, after the temperature is reduced to below 0 ℃, adding hexafluorophosphoric acid, reacting for 0.5h, dropwise adding the solution obtained in the step (2) into a reaction system, controlling the temperature to be below 10 ℃, continuing to react for 1-3 h after the dropwise adding is finished, after the reaction is finished, carrying out suction filtration, repeatedly washing a filter cake with water, carrying out vacuum drying to obtain a yellow solid, dissolving the solid in a mixed solution of THF and DMF, carrying out suction filtration, pouring distilled water into a filtrate, continuously stirring until no solid is separated out, carrying out suction filtration, and carrying out vacuum drying to obtain an orange-yellow solid di-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diaza pentadiene hexafluorophosphate;
wherein the molar ratio of the sodium hydroxide to the hexafluorophosphoric acid is 1: 1-5: 1; the mass-volume ratio of the sodium hydroxide to the distilled water is 1: 10-1: 15; the volume ratio of the THF and DMF mixed solution to the hexafluorophosphoric acid is 3: 1-10: 1;
(4) bis-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diazapentadien hexafluorophosphate, nitrobenzamidine hydrochloride and DMSO were placed in a dry 500ml reactor, stirred to a suspension, and CH was slowly dropped thereinto at room temperature3ONa/CH3OH, DMSO and CH3After the dripping of the mixed solution of OH, controlling the temperature of a reaction system at 70-75 ℃, continuously reacting for 9 hours, then cooling the reaction system to room temperature, carrying out suction filtration, washing the solid with water and methanol for 3 times in sequence, and carrying out vacuum pumping to obtain a yellowish-brown solid bipyrimidine nitro compound; wherein the molar ratio of the bis-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diazapentadiene hexafluorophosphate to the nitrobenzamidine hydrochloride and sodium methoxide is 1: 1: 1-1: 5: 6; DMSO in CH3ONa/CH3OH, DMSO and CH3The mass fraction of the OH mixed solution is 70-85%;
(5) Under the protection of nitrogen, dissolving a dipyrimidine nitro compound and Pd/C in tetrahydrofuran, heating until reflux, slowly dripping hydrazine hydrate, continuously refluxing for 5-10 h after dripping, carrying out suction filtration while hot, carrying out rotary evaporation on filtrate, washing the obtained solid with water and absolute ethyl alcohol in sequence, and then carrying out vacuum pumping to obtain yellow crystals, namely dipyrimidine diamine;
wherein the mass ratio of the dipyrimidine nitro compound to Pd/C is 3: 1-5: 1; the volume ratio of the bipyrimidine nitro compound to tetrahydrofuran is 1: 8-1: 12;
(6) adding salicylic acid into a clean reaction container, introducing nitrogen for protection, heating to enable the salicylic acid to be in a molten state, then adding the bipyrimidine diamine and dianhydride monomer obtained in the step (5) at 160-210 ℃, adding a small molecular substance, and carrying out sealed stirring reaction for 1-24 hours to obtain a viscous polyimide spinning solution;
wherein the molar ratio of the bispyrimidine diamine to the dianhydride monomer is 1: 0.95-1.05, and the sum of the weight of the bispyrimidine diamine and the dianhydride monomer accounts for 10-25% of the total weight of the polyimide spinning solution; the added micromolecular substance is one or a mixture of more of isoquinoline, acetic anhydride, triethylamine and pyridine, and the adding amount of the micromolecular substance is 0.1-3% of the total weight of the obtained polyimide spinning solution;
The dianhydride monomer is at least one of 3,3 ', 4,4 ' -diphenyl ether tetracarboxylic dianhydride, 4,4 ' - (hexafluoroisopropylidene) diphthalic anhydride, bisphenol A diether dianhydride, 3 ', 4,4 ' -biphenyl tetracarboxylic dianhydride, 3 ', 4,4 ' -benzophenone tetracarboxylic dianhydride or 1,2,4, 5-pyromellitic dianhydride;
(7) standing and defoaming the polyimide spinning solution, then carrying out wet spinning or dry-wet spinning, solidifying, washing with water, and then winding to obtain the bipyrimidine ring-containing polyimide nascent fiber; wherein the temperature of spinning solution in wet or dry-wet spinning is 60-180 ℃, the diameter of a spinneret orifice is 0.02-0.6 mm, the length-diameter ratio is 2-8: 1, and the winding speed is 2-50 m/min; the solidification is carried out by passing through a section of 5-50 mm air bath or directly entering a solidification bath with the length of 1-3 m for solidification; the water washing is carried out by a water washing tank at the temperature of 30-80 ℃, the coagulating bath is one or a mixture of deionized water, methanol, ethanol and acetone, and the temperature is 50-100 ℃;
(8) Drying the polyimide nascent fiber containing the bipyrimidine ring at 90-110 ℃ for 1-3 h, and then carrying out hot stretching on the polyimide nascent fiber through a heat pipe with the length of 1-5 m to obtain the polyimide fiber; wherein the feeding speed of the polyimide fiber in the thermal stretching process is 4-50 m/min, the stretching ratio is 1-8 times, and the stretching temperature is 350-550 ℃.
in one embodiment, the polar organic solvent in step (2) is one or more of DMAC, DMF, DMSO, N-methylpyrrolidone.
in one embodiment, the volume ratio of THF to DMF in the THF-DMF mixed solution in step (3) is 0.5: 1-2: 1.
in one embodiment, the CH in step (4)3ONa in CH3ONa/CH3the mass fraction of the OH solution is 30-65%.
in one embodiment, the hydrazine hydrate in step (5) is 80% by weight.
In one embodiment, the mass fraction of 80% hydrazine hydrate to bipyrimidine nitro compound in step (5) is 3: 1-6: 1.
in one embodiment, the molar ratio of the bispyrimidinediamine to the dianhydride monomer in step (6) is 1: 1.
in one embodiment, the temperature of the spinning dope in step (7) is 150 ℃.
in one embodiment, the stretch ratio in step (8) is 6 times.
the above-described and other features, aspects, and advantages of the present application will become more apparent with reference to the following detailed description.
Detailed Description
the present invention will be specifically described below by way of examples. It should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and that the insubstantial modifications and adaptations of the present invention by those skilled in the art based on the above disclosure are still within the scope of the present invention.
In addition, the starting materials used are commercially available, unless otherwise specified, and the parts used for the following materials are parts by weight.
Example 1
The preparation method of the polyimide comprises the following steps:
(1) putting the p-nitrobenzonitrile and anhydrous methanol into a dry 500ml reactor, and adding CH while stirring3ONa/CH3The OH solution is stirred for 8 hours at room temperature, and acetic acid is added to neutralize CH in the system3ONa, stirring for 30min, adding NH4Cl, controlling the temperature to be 35 ℃, reacting for 10h at the temperature, cooling to room temperature, evaporating methanol to obtain a solid, repeatedly washing the solid with acetone, and performing vacuum pumping to obtain beige solid p-nitrobenzamidine hydrochloride;
wherein the molar ratio of the p-nitrobenzonitrile to the ammonium chloride, the sodium methoxide and the acetic acid is 15: 12: 1:1, the volume ratio of the organic solvent anhydrous methanol to the p-nitrobenzonitrile is 8:1, CH3ONa in CH3ONa/CH3the mass fraction of the OH solution is 45 percent;
(2) Placing p-phenylenediacetic acid and DMSO in a dry 500ml reactorslowly dropping POCl in the stirring process3controlling the temperature to be below 70 ℃ in the dripping process, controlling the temperature to be 65 ℃ after finishing dripping, reacting for 3h, and cooling to room temperature;
Wherein the p-phenylenediacetic acid and POCl3in a molar ratio of 1: 4; the volume ratio of the organic solvent with high polarity to the p-phenylenediacetic acid is 12: 1;
(3) Placing sodium hydroxide and distilled water in a dry 500ml reactor, mechanically stirring in a low-temperature reaction bath, after the temperature is reduced to below 0 ℃, adding hexafluorophosphoric acid, reacting for 0.5h, dropwise adding the solution obtained in the step (2) into a reaction system, controlling the temperature to be below 10 ℃, continuing to react for 2h after the dropwise adding is finished, after the reaction is finished, carrying out suction filtration, repeatedly washing a filter cake with water, carrying out vacuum drying to obtain a yellow solid, dissolving the solid in a mixed solution of THF and DMF, carrying out suction filtration, pouring distilled water into the filtrate, continuously stirring until no solid is separated out, carrying out suction filtration, and carrying out vacuum drying to obtain orange-yellow solid di-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diaza pentadiene hexafluorophosphate;
Wherein the molar ratio of the sodium hydroxide to the hexafluorophosphoric acid is 3: 1; the mass-volume ratio of the sodium hydroxide to the distilled water is 1: 10; the volume ratio of the THF and DMF mixed solution to the hexafluorophosphoric acid is 5: 1; the volume ratio of THF to DMF was 1: 1;
(4) bis-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diazapentadien hexafluorophosphate, nitrobenzamidine hydrochloride and DMSO were placed in a dry 500ml reactor, stirred to a suspension, and CH was slowly dropped thereinto at room temperature3ONa/CH3OH, DMSO and CH3after the dripping of the mixed solution of OH, controlling the temperature of the reaction system at 70 ℃, continuously reacting for 9 hours, then cooling the reaction system to room temperature, carrying out suction filtration, washing the solid with water and methanol for 3 times in sequence, and carrying out vacuum pumping to obtain a yellowish-brown solid bipyrimidine nitro compound;
wherein the molar ratio of the bis-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diazapentadiene hexafluorophosphate to the nitrobenzamidine hydrochloride and sodium methoxide is 1: 5: 6; DMSO in CH3ONa/CH3OH, DMSO and CH3The mass fraction of the OH mixed solution is 75 percent;
(5) under the protection of nitrogen, dissolving a dipyrimidine nitro compound and Pd/C in tetrahydrofuran, heating to reflux, slowly dripping hydrazine hydrate with the mass fraction of 80%, continuously refluxing for 8 hours after dripping, carrying out suction filtration while hot, carrying out rotary evaporation on filtrate, washing the obtained solid with water and absolute ethyl alcohol in sequence, and carrying out vacuum pumping to obtain yellow crystals, namely dipyrimidine diamine;
Wherein the mass ratio of the dipyrimidine nitro compound to Pd/C is 4: 1; the volume ratio of the bipyrimidine nitro compound to tetrahydrofuran is 1: 8-1: 12; the volume ratio of 80% hydrazine hydrate to the dipyrimidine nitro compound is 5: 1;
(6) adding salicylic acid into a clean reaction container, introducing nitrogen for protection, heating to enable the salicylic acid to be in a molten state, then adding the bipyrimidine diamine and dianhydride monomer obtained in the step (5) at 180 ℃, adding a small molecular substance, and carrying out sealed stirring reaction for 5 hours to obtain a viscous polyimide spinning solution;
Wherein the molar ratio of the bispyrimidine diamine to the dianhydride monomer is 1:1, and the sum of the weight of the bispyrimidine diamine and the dianhydride monomer accounts for 15 percent of the total weight of the polyimide spinning solution; the added micromolecular substance is one or a mixture of more of isoquinoline, acetic anhydride, triethylamine and pyridine, and the adding amount of the micromolecular substance is 0.1-3% of the total weight of the obtained polyimide spinning solution;
The dianhydride monomer is 3,3 ', 4, 4' -diphenyl ether tetracarboxylic dianhydride;
(7) Standing and defoaming the polyimide spinning solution, then carrying out wet spinning or dry-wet spinning, solidifying, washing with water, and then winding to obtain the bipyrimidine ring-containing polyimide nascent fiber; wherein the temperature of spinning solution in wet spinning or dry-wet spinning is 150 ℃, the diameter of a spinneret orifice is 0.2mm, the length-diameter ratio is 6:1, and the winding speed is 30 m/min; the solidification is that the mixture passes through a section of 50mm air bath or directly enters a solidification bath groove with the length of 2m for solidification; the water washing is carried out by a 50 ℃ water washing tank, the coagulating bath is one or a mixture of deionized water, methanol, ethanol and acetone, and the temperature is 60 ℃;
(8) Drying the polyimide nascent fiber containing the bipyrimidine ring at 100 ℃ for 2h, and then carrying out hot stretching on the polyimide nascent fiber through a hot pipe with the length of 2m to obtain the polyimide fiber; wherein the feeding speed of the polyimide fiber in the hot stretching process is 30m/min, the stretching ratio is 6 times, and the stretching temperature is 400 ℃.
example 2
the preparation method of the polyimide comprises the following steps:
(1) putting the p-nitrobenzonitrile and anhydrous methanol into a dry 500ml reactor, and adding CH while stirring3ONa/CH3The OH solution is stirred for 8 hours at room temperature, and acetic acid is added to neutralize CH in the system3ONa, stirring for 30min, adding NH4Cl, controlling the temperature to be 35 ℃, reacting for 10h at the temperature, cooling to room temperature, evaporating methanol to obtain a solid, repeatedly washing the solid with acetone, and performing vacuum pumping to obtain beige solid p-nitrobenzamidine hydrochloride;
Wherein the molar ratio of the p-nitrobenzonitrile to the ammonium chloride, the sodium methoxide and the acetic acid is 15: 12: 1:1, the volume ratio of the organic solvent anhydrous methanol to the p-nitrobenzonitrile is 8:1, CH3ONa in CH3ONa/CH3the mass fraction of the OH solution is 45 percent;
(2) placing p-phenylenediacetic acid and DMSO in a dry 500ml reactor, and slowly dropping POCl in the process of stirring3controlling the temperature to be below 70 ℃ in the dripping process, controlling the temperature to be 65 ℃ after finishing dripping, reacting for 3h, and cooling to room temperature;
Wherein the p-phenylenediacetic acid and POCl3In a molar ratio of 1: 4; the volume ratio of the organic solvent with high polarity to the p-phenylenediacetic acid is 12: 1;
(3) Placing sodium hydroxide and distilled water in a dry 500ml reactor, mechanically stirring in a low-temperature reaction bath, after the temperature is reduced to below 0 ℃, adding hexafluorophosphoric acid, reacting for 0.5h, dropwise adding the solution obtained in the step (2) into a reaction system, controlling the temperature to be below 10 ℃, continuing to react for 2h after the dropwise adding is finished, after the reaction is finished, carrying out suction filtration, repeatedly washing a filter cake with water, carrying out vacuum drying to obtain a yellow solid, dissolving the solid in a mixed solution of THF and DMF, carrying out suction filtration, pouring distilled water into the filtrate, continuously stirring until no solid is separated out, carrying out suction filtration, and carrying out vacuum drying to obtain orange-yellow solid di-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diaza pentadiene hexafluorophosphate;
Wherein the molar ratio of the sodium hydroxide to the hexafluorophosphoric acid is 3: 1; the mass-volume ratio of the sodium hydroxide to the distilled water is 1: 10; the volume ratio of the THF and DMF mixed solution to the hexafluorophosphoric acid is 5: 1; the volume ratio of THF to DMF was 1: 1;
(4) bis-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diazapentadien hexafluorophosphate, nitrobenzamidine hydrochloride and DMSO were placed in a dry 500ml reactor, stirred to a suspension, and CH was slowly dropped thereinto at room temperature3ONa/CH3OH, DMSO and CH3after the dripping of the mixed solution of OH, controlling the temperature of the reaction system at 70 ℃, continuously reacting for 9 hours, then cooling the reaction system to room temperature, carrying out suction filtration, washing the solid with water and methanol for 3 times in sequence, and carrying out vacuum pumping to obtain a yellowish-brown solid bipyrimidine nitro compound;
Wherein the molar ratio of the bis-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diazapentadiene hexafluorophosphate to the nitrobenzamidine hydrochloride and sodium methoxide is 1: 5: 6; DMSO in CH3ONa/CH3OH, DMSO and CH3the mass fraction of the OH mixed solution is 75 percent;
(5) under the protection of nitrogen, dissolving a dipyrimidine nitro compound and Pd/C in tetrahydrofuran, heating to reflux, slowly dripping hydrazine hydrate with the mass fraction of 80%, continuously refluxing for 8 hours after dripping, carrying out suction filtration while hot, carrying out rotary evaporation on filtrate, washing the obtained solid with water and absolute ethyl alcohol in sequence, and carrying out vacuum pumping to obtain yellow crystals, namely dipyrimidine diamine;
Wherein the mass ratio of the dipyrimidine nitro compound to Pd/C is 4: 1; the volume ratio of the bipyrimidine nitro compound to tetrahydrofuran is 1: 8-1: 12; the volume ratio of 80% hydrazine hydrate to the dipyrimidine nitro compound is 5: 1;
(6) adding salicylic acid into a clean reaction container, introducing nitrogen for protection, heating to enable the salicylic acid to be in a molten state, then adding the bipyrimidine diamine and dianhydride monomer obtained in the step (5) at 180 ℃, adding a small molecular substance, and carrying out sealed stirring reaction for 5 hours to obtain a viscous polyimide spinning solution;
Wherein the molar ratio of the bispyrimidine diamine to the dianhydride monomer is 1:1, and the sum of the weight of the bispyrimidine diamine and the dianhydride monomer accounts for 15 percent of the total weight of the polyimide spinning solution; the added micromolecular substance is one or a mixture of more of isoquinoline, acetic anhydride, triethylamine and pyridine, and the adding amount of the micromolecular substance is 0.1-3% of the total weight of the obtained polyimide spinning solution;
the dianhydride monomer is 4, 4' - (hexafluoroisopropylidene) diphthalic anhydride;
(7) standing and defoaming the polyimide spinning solution, then carrying out wet spinning or dry-wet spinning, solidifying, washing with water, and then winding to obtain the bipyrimidine ring-containing polyimide nascent fiber; wherein the temperature of spinning solution in wet spinning or dry-wet spinning is 150 ℃, the diameter of a spinneret orifice is 0.2mm, the length-diameter ratio is 6:1, and the winding speed is 30 m/min; the solidification is that the mixture passes through a section of 50mm air bath or directly enters a solidification bath groove with the length of 2m for solidification; the water washing is carried out by a 50 ℃ water washing tank, the coagulating bath is one or a mixture of deionized water, methanol, ethanol and acetone, and the temperature is 60 ℃;
(8) drying the polyimide nascent fiber containing the bipyrimidine ring at 100 ℃ for 2h, and then carrying out hot stretching on the polyimide nascent fiber through a hot pipe with the length of 2m to obtain the polyimide fiber; wherein the feeding speed of the polyimide fiber in the hot stretching process is 30m/min, the stretching ratio is 6 times, and the stretching temperature is 400 ℃.
Example 3
The preparation method of the polyimide comprises the following steps:
(1) Putting the p-nitrobenzonitrile and anhydrous methanol into a dry 500ml reactor, and adding CH while stirring3ONa/CH3The OH solution is stirred for 8 hours at room temperature, and acetic acid is added to neutralize CH in the system3ONa, stirring for 30min, adding NH4Cl, controlling the temperature to be 35 ℃, reacting for 10h at the temperature, cooling to room temperature, evaporating methanol to obtain a solid, repeatedly washing the solid with acetone, and performing vacuum pumping to obtain beige solid p-nitrobenzamidine hydrochloride;
Wherein, the nitreThe molar ratio of cyanobenzene to ammonium chloride, sodium methoxide and acetic acid is 15: 12: 1:1, the volume ratio of the organic solvent anhydrous methanol to the p-nitrobenzonitrile is 8:1, CH3ONa in CH3ONa/CH3the mass fraction of the OH solution is 45 percent;
(2) placing p-phenylenediacetic acid and DMSO into a dry 500ml reactor, slowly dripping POCl3 in the stirring process, controlling the temperature below 70 ℃ in the dripping process, controlling the temperature at 65 ℃ after finishing dripping, reacting for 3h, and cooling to room temperature;
wherein the molar ratio of the p-phenylenediacetic acid to the POCl3 is 1: 4; the volume ratio of the organic solvent with high polarity to the p-phenylenediacetic acid is 12: 1;
(3) placing sodium hydroxide and distilled water in a dry 500ml reactor, mechanically stirring in a low-temperature reaction bath, after the temperature is reduced to below 0 ℃, adding hexafluorophosphoric acid, reacting for 0.5h, dropwise adding the solution obtained in the step (2) into a reaction system, controlling the temperature to be below 10 ℃, continuing to react for 2h after the dropwise adding is finished, after the reaction is finished, carrying out suction filtration, repeatedly washing a filter cake with water, carrying out vacuum drying to obtain a yellow solid, dissolving the solid in a mixed solution of THF and DMF, carrying out suction filtration, pouring distilled water into the filtrate, continuously stirring until no solid is separated out, carrying out suction filtration, and carrying out vacuum drying to obtain orange-yellow solid di-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diaza pentadiene hexafluorophosphate;
wherein the molar ratio of the sodium hydroxide to the hexafluorophosphoric acid is 3: 1; the mass-volume ratio of the sodium hydroxide to the distilled water is 1: 10; the volume ratio of the THF and DMF mixed solution to the hexafluorophosphoric acid is 5: 1; the volume ratio of THF to DMF was 1: 1;
(4) bis-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diazapentadien hexafluorophosphate, nitrobenzamidine hydrochloride and DMSO were placed in a dry 500ml reactor, stirred to a suspension, and CH was slowly dropped thereinto at room temperature3ONa/CH3OH, DMSO and CH3Controlling the temperature of the reaction system at 70 ℃ after the dripping of the mixed solution of OH, continuously reacting for 9 hours, cooling the reaction system to room temperature, carrying out suction filtration, washing the solid with water and methanol for 3 times in sequence, and carrying out vacuum pumping to obtain the yellowish-brown solid bipyrimidine nitroylated productA compound;
Wherein the molar ratio of the bis-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diazapentadiene hexafluorophosphate to the nitrobenzamidine hydrochloride and sodium methoxide is 1: 5: 6; DMSO in CH3ONa/CH3OH, DMSO and CH3The mass fraction of the OH mixed solution is 75 percent;
(5) Under the protection of nitrogen, dissolving a dipyrimidine nitro compound and Pd/C in tetrahydrofuran, heating to reflux, slowly dripping hydrazine hydrate with the mass fraction of 80%, continuously refluxing for 8 hours after dripping, carrying out suction filtration while hot, carrying out rotary evaporation on filtrate, washing the obtained solid with water and absolute ethyl alcohol in sequence, and carrying out vacuum pumping to obtain yellow crystals, namely dipyrimidine diamine;
Wherein the mass ratio of the dipyrimidine nitro compound to Pd/C is 4: 1; the volume ratio of the bipyrimidine nitro compound to tetrahydrofuran is 1: 8-1: 12; the volume ratio of 80% hydrazine hydrate to the dipyrimidine nitro compound is 5: 1;
(6) adding salicylic acid into a clean reaction container, introducing nitrogen for protection, heating to enable the salicylic acid to be in a molten state, then adding the bipyrimidine diamine and dianhydride monomer obtained in the step (5) at 180 ℃, adding a small molecular substance, and carrying out sealed stirring reaction for 5 hours to obtain a viscous polyimide spinning solution;
wherein the molar ratio of the bispyrimidine diamine to the dianhydride monomer is 1:1, and the sum of the weight of the bispyrimidine diamine and the dianhydride monomer accounts for 15 percent of the total weight of the polyimide spinning solution; the added micromolecular substance is one or a mixture of more of isoquinoline, acetic anhydride, triethylamine and pyridine, and the adding amount of the micromolecular substance is 0.1-3% of the total weight of the obtained polyimide spinning solution;
The dianhydride monomer is bisphenol A type diether dianhydride;
(7) standing and defoaming the polyimide spinning solution, then carrying out wet spinning or dry-wet spinning, solidifying, washing with water, and then winding to obtain the bipyrimidine ring-containing polyimide nascent fiber; wherein the temperature of spinning solution in wet spinning or dry-wet spinning is 150 ℃, the diameter of a spinneret orifice is 0.2mm, the length-diameter ratio is 6:1, and the winding speed is 30 m/min; the solidification is that the mixture passes through a section of 50mm air bath or directly enters a solidification bath groove with the length of 2m for solidification; the water washing is carried out by a 50 ℃ water washing tank, the coagulating bath is one or a mixture of deionized water, methanol, ethanol and acetone, and the temperature is 60 ℃;
(8) Drying the polyimide nascent fiber containing the bipyrimidine ring at 100 ℃ for 2h, and then carrying out hot stretching on the polyimide nascent fiber through a hot pipe with the length of 2m to obtain the polyimide fiber; wherein the feeding speed of the polyimide fiber in the hot stretching process is 30m/min, the stretching ratio is 6 times, and the stretching temperature is 400 ℃.
example 4
The preparation method of the polyimide comprises the following steps:
(1) putting the p-nitrobenzonitrile and anhydrous methanol into a dry 500ml reactor, and adding CH while stirring3ONa/CH3the OH solution is stirred for 8 hours at room temperature, and acetic acid is added to neutralize CH in the system3ONa, stirring for 30min, adding NH4cl, controlling the temperature to be 35 ℃, reacting for 10h at the temperature, cooling to room temperature, evaporating methanol to obtain a solid, repeatedly washing the solid with acetone, and performing vacuum pumping to obtain beige solid p-nitrobenzamidine hydrochloride;
wherein the molar ratio of the p-nitrobenzonitrile to the ammonium chloride, the sodium methoxide and the acetic acid is 20: 18: 3:1, the volume ratio of the organic solvent anhydrous methanol to the p-nitrobenzonitrile is 8:1, CH3ONa in CH3ONa/CH3The mass fraction of the OH solution is 45 percent;
(2) placing p-phenylenediacetic acid and DMSO in a dry 500ml reactor, and slowly dropping POCl in the process of stirring3controlling the temperature to be below 70 ℃ in the dripping process, controlling the temperature to be 65 ℃ after finishing dripping, reacting for 3h, and cooling to room temperature;
wherein the p-phenylenediacetic acid and POCl3In a molar ratio of 1: 4; the volume ratio of the organic solvent with high polarity to the p-phenylenediacetic acid is 12: 1;
(3) Placing sodium hydroxide and distilled water in a dry 500ml reactor, mechanically stirring in a low-temperature reaction bath, after the temperature is reduced to below 0 ℃, adding hexafluorophosphoric acid, reacting for 0.5h, dropwise adding the solution obtained in the step (2) into a reaction system, controlling the temperature to be below 10 ℃, continuing to react for 2h after the dropwise adding is finished, after the reaction is finished, carrying out suction filtration, repeatedly washing a filter cake with water, carrying out vacuum drying to obtain a yellow solid, dissolving the solid in a mixed solution of THF and DMF, carrying out suction filtration, pouring distilled water into the filtrate, continuously stirring until no solid is separated out, carrying out suction filtration, and carrying out vacuum drying to obtain orange-yellow solid di-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diaza pentadiene hexafluorophosphate;
Wherein the molar ratio of the sodium hydroxide to the hexafluorophosphoric acid is 3: 1; the mass-volume ratio of the sodium hydroxide to the distilled water is 1: 10; the volume ratio of the THF and DMF mixed solution to the hexafluorophosphoric acid is 5: 1; the volume ratio of THF to DMF was 1: 1;
(4) bis-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diazapentadien hexafluorophosphate, nitrobenzamidine hydrochloride and DMSO were placed in a dry 500ml reactor, stirred to a suspension, and CH was slowly dropped thereinto at room temperature3ONa/CH3OH, DMSO and CH3After the dripping of the mixed solution of OH, controlling the temperature of the reaction system at 70 ℃, continuously reacting for 9 hours, then cooling the reaction system to room temperature, carrying out suction filtration, washing the solid with water and methanol for 3 times in sequence, and carrying out vacuum pumping to obtain a yellowish-brown solid bipyrimidine nitro compound;
Wherein the molar ratio of the bis-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diazapentadiene hexafluorophosphate to the nitrobenzamidine hydrochloride and sodium methoxide is 1: 5: 6; DMSO in CH3ONa/CH3OH, DMSO and CH3the mass fraction of the OH mixed solution is 75 percent;
(5) under the protection of nitrogen, dissolving a dipyrimidine nitro compound and Pd/C in tetrahydrofuran, heating to reflux, slowly dripping hydrazine hydrate with the mass fraction of 80%, continuously refluxing for 8 hours after dripping, carrying out suction filtration while hot, carrying out rotary evaporation on filtrate, washing the obtained solid with water and absolute ethyl alcohol in sequence, and carrying out vacuum pumping to obtain yellow crystals, namely dipyrimidine diamine;
wherein the mass ratio of the dipyrimidine nitro compound to Pd/C is 4: 1; the volume ratio of the bipyrimidine nitro compound to tetrahydrofuran is 1: 8-1: 12; the volume ratio of 80% hydrazine hydrate to the dipyrimidine nitro compound is 5: 1;
(6) Adding salicylic acid into a clean reaction container, introducing nitrogen for protection, heating to enable the salicylic acid to be in a molten state, then adding the bipyrimidine diamine and dianhydride monomer obtained in the step (5) at 180 ℃, adding a small molecular substance, and carrying out sealed stirring reaction for 5 hours to obtain a viscous polyimide spinning solution;
Wherein the molar ratio of the bispyrimidine diamine to the dianhydride monomer is 1:1, and the sum of the weight of the bispyrimidine diamine and the dianhydride monomer accounts for 10-25% of the total weight of the polyimide spinning solution; the added micromolecular substance is one or a mixture of more of isoquinoline, acetic anhydride, triethylamine and pyridine, and the adding amount of the micromolecular substance is 0.1-3% of the total weight of the obtained polyimide spinning solution;
the dianhydride monomer is 3,3 ', 4, 4' -biphenyl tetracarboxylic dianhydride;
(7) standing and defoaming the polyimide spinning solution, then carrying out wet spinning or dry-wet spinning, solidifying, washing with water, and then winding to obtain the bipyrimidine ring-containing polyimide nascent fiber; wherein the temperature of spinning solution in wet spinning or dry-wet spinning is 150 ℃, the diameter of a spinneret orifice is 0.2mm, the length-diameter ratio is 6:1, and the winding speed is 30 m/min; the solidification is that the mixture passes through a section of 50mm air bath or directly enters a solidification bath groove with the length of 2m for solidification; the water washing is carried out by a 50 ℃ water washing tank, the coagulating bath is one or a mixture of deionized water, methanol, ethanol and acetone, and the temperature is 60 ℃;
(8) drying the polyimide nascent fiber containing the bipyrimidine ring at 100 ℃ for 2h, and then carrying out hot stretching on the polyimide nascent fiber through a hot pipe with the length of 2m to obtain the polyimide fiber; wherein the feeding speed of the polyimide fiber in the hot stretching process is 30m/min, the stretching ratio is 6 times, and the stretching temperature is 400 ℃.
example 5
the preparation method of the polyimide comprises the following steps:
(1) Putting the p-nitrobenzonitrile and anhydrous methanol into a dry 500ml reactor, and adding CH while stirring3ONa/CH3The OH solution is stirred for 8 hours at room temperature, and acetic acid is added to neutralize CH in the system3ONa, stirring for 30min, adding NH4Cl, controlling the temperature to be 35 ℃, reacting for 10h at the temperature, cooling to room temperature, evaporating methanol to obtain a solid, repeatedly washing the solid with acetone, and performing vacuum pumping to obtain beige solid p-nitrobenzamidine hydrochloride;
Wherein the molar ratio of the p-nitrobenzonitrile to the ammonium chloride, the sodium methoxide and the acetic acid is 20: 18: 3:1, the volume ratio of the organic solvent anhydrous methanol to the p-nitrobenzonitrile is 8:1, CH3ONa in CH3ONa/CH3The mass fraction of the OH solution is 45 percent;
(2) Placing p-phenylenediacetic acid and DMSO in a dry 500ml reactor, and slowly dropping POCl in the process of stirring3controlling the temperature to be below 70 ℃ in the dripping process, controlling the temperature to be 65 ℃ after finishing dripping, reacting for 3h, and cooling to room temperature;
wherein the p-phenylenediacetic acid and POCl3In a molar ratio of 1: 4; the volume ratio of the organic solvent with high polarity to the p-phenylenediacetic acid is 12: 1;
(3) Placing sodium hydroxide and distilled water in a dry 500ml reactor, mechanically stirring in a low-temperature reaction bath, after the temperature is reduced to below 0 ℃, adding hexafluorophosphoric acid, reacting for 0.5h, dropwise adding the solution obtained in the step (2) into a reaction system, controlling the temperature to be below 10 ℃, continuing to react for 2h after the dropwise adding is finished, after the reaction is finished, carrying out suction filtration, repeatedly washing a filter cake with water, carrying out vacuum drying to obtain a yellow solid, dissolving the solid in a mixed solution of THF and DMF, carrying out suction filtration, pouring distilled water into the filtrate, continuously stirring until no solid is separated out, carrying out suction filtration, and carrying out vacuum drying to obtain orange-yellow solid di-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diaza pentadiene hexafluorophosphate;
Wherein the molar ratio of the sodium hydroxide to the hexafluorophosphoric acid is 3: 1; the mass-volume ratio of the sodium hydroxide to the distilled water is 1: 10; the volume ratio of the THF and DMF mixed solution to the hexafluorophosphoric acid is 5: 1; the volume ratio of THF to DMF was 1: 1;
(4) Di-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diaza-pentadiene hexafluorophosphate, nitrobenzamidine hydrochloride and DMSO were placed in a dry 500ml reactor and stirred to suspensionLiquid, at room temperature, CH was slowly dropped thereinto3ONa/CH3OH, DMSO and CH3after the dripping of the mixed solution of OH, controlling the temperature of the reaction system at 70 ℃, continuously reacting for 9 hours, then cooling the reaction system to room temperature, carrying out suction filtration, washing the solid with water and methanol for 3 times in sequence, and carrying out vacuum pumping to obtain a yellowish-brown solid bipyrimidine nitro compound;
Wherein the molar ratio of the bis-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diazapentadiene hexafluorophosphate to the nitrobenzamidine hydrochloride and sodium methoxide is 1: 5: 6; DMSO in CH3ONa/CH3OH, DMSO and CH3the mass fraction of the OH mixed solution is 75 percent;
(5) Under the protection of nitrogen, dissolving a dipyrimidine nitro compound and Pd/C in tetrahydrofuran, heating to reflux, slowly dripping hydrazine hydrate with the mass fraction of 80%, continuously refluxing for 8 hours after dripping, carrying out suction filtration while hot, carrying out rotary evaporation on filtrate, washing the obtained solid with water and absolute ethyl alcohol in sequence, and carrying out vacuum pumping to obtain yellow crystals, namely dipyrimidine diamine;
wherein the mass ratio of the dipyrimidine nitro compound to Pd/C is 4: 1; the volume ratio of the bipyrimidine nitro compound to tetrahydrofuran is 1: 8-1: 12; the volume ratio of 80% hydrazine hydrate to the dipyrimidine nitro compound is 5: 1;
(6) adding salicylic acid into a clean reaction container, introducing nitrogen for protection, heating to enable the salicylic acid to be in a molten state, then adding the bipyrimidine diamine and dianhydride monomer obtained in the step (5) at 180 ℃, adding a small molecular substance, and carrying out sealed stirring reaction for 5 hours to obtain a viscous polyimide spinning solution;
wherein the molar ratio of the bispyrimidine diamine to the dianhydride monomer is 1:1, and the sum of the weight of the bispyrimidine diamine and the dianhydride monomer accounts for 15 percent of the total weight of the polyimide spinning solution; the added micromolecular substance is one or a mixture of more of isoquinoline, acetic anhydride, triethylamine and pyridine, and the adding amount of the micromolecular substance is 0.1-3% of the total weight of the obtained polyimide spinning solution;
The dianhydride monomer is 3,3 ', 4, 4' -benzophenone tetracarboxylic dianhydride;
(7) Standing and defoaming the polyimide spinning solution, then carrying out wet spinning or dry-wet spinning, solidifying, washing with water, and then winding to obtain the bipyrimidine ring-containing polyimide nascent fiber; wherein the temperature of spinning solution in wet spinning or dry-wet spinning is 150 ℃, the diameter of a spinneret orifice is 0.2mm, the length-diameter ratio is 6:1, and the winding speed is 30 m/min; the solidification is that the mixture passes through a section of 50mm air bath or directly enters a solidification bath groove with the length of 2m for solidification; the water washing is carried out by a 50 ℃ water washing tank, the coagulating bath is one or a mixture of deionized water, methanol, ethanol and acetone, and the temperature is 60 ℃;
(8) drying the polyimide nascent fiber containing the bipyrimidine ring at 100 ℃ for 2h, and then carrying out hot stretching on the polyimide nascent fiber through a hot pipe with the length of 2m to obtain the polyimide fiber; wherein the feeding speed of the polyimide fiber in the hot stretching process is 30m/min, the stretching ratio is 6 times, and the stretching temperature is 400 ℃.
example 6
the preparation method of the polyimide comprises the following steps:
(1) Putting the p-nitrobenzonitrile and anhydrous methanol into a dry 500ml reactor, and adding CH while stirring3ONa/CH3The OH solution is stirred for 8 hours at room temperature, and acetic acid is added to neutralize CH in the system3ONa, stirring for 30min, adding NH4Cl, controlling the temperature to be 35 ℃, reacting for 10h at the temperature, cooling to room temperature, evaporating methanol to obtain a solid, repeatedly washing the solid with acetone, and performing vacuum pumping to obtain beige solid p-nitrobenzamidine hydrochloride;
Wherein the molar ratio of the p-nitrobenzonitrile to the ammonium chloride, the sodium methoxide and the acetic acid is 20: 18: 3:1, the volume ratio of the organic solvent anhydrous methanol to the p-nitrobenzonitrile is 8:1, CH3ONa in CH3ONa/CH3the mass fraction of the OH solution is 45 percent;
(2) placing p-phenylenediacetic acid and DMSO in a dry 500ml reactor, and slowly dropping POCl in the process of stirring3controlling the temperature to be below 70 ℃ in the dripping process, controlling the temperature to be 65 ℃ after finishing dripping, reacting for 3h, and cooling to room temperature;
Wherein the p-phenylenediacetic acid andPOCl3in a molar ratio of 1: 4; the volume ratio of the organic solvent with high polarity to the p-phenylenediacetic acid is 12: 1;
(3) Placing sodium hydroxide and distilled water in a dry 500ml reactor, mechanically stirring in a low-temperature reaction bath, after the temperature is reduced to below 0 ℃, adding hexafluorophosphoric acid, reacting for 0.5h, dropwise adding the solution obtained in the step (2) into a reaction system, controlling the temperature to be below 10 ℃, continuing to react for 2h after the dropwise adding is finished, after the reaction is finished, carrying out suction filtration, repeatedly washing a filter cake with water, carrying out vacuum drying to obtain a yellow solid, dissolving the solid in a mixed solution of THF and DMF, carrying out suction filtration, pouring distilled water into the filtrate, continuously stirring until no solid is separated out, carrying out suction filtration, and carrying out vacuum drying to obtain orange-yellow solid di-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diaza pentadiene hexafluorophosphate;
Wherein the molar ratio of the sodium hydroxide to the hexafluorophosphoric acid is 3: 1; the mass-volume ratio of the sodium hydroxide to the distilled water is 1: 10; the volume ratio of the THF and DMF mixed solution to the hexafluorophosphoric acid is 5: 1; the volume ratio of THF to DMF was 1: 1;
(4) bis-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diazapentadien hexafluorophosphate, nitrobenzamidine hydrochloride and DMSO were placed in a dry 500ml reactor, stirred to a suspension, and CH was slowly dropped thereinto at room temperature3ONa/CH3OH, DMSO and CH3after the dripping of the mixed solution of OH, controlling the temperature of the reaction system at 70 ℃, continuously reacting for 9 hours, then cooling the reaction system to room temperature, carrying out suction filtration, washing the solid with water and methanol for 3 times in sequence, and carrying out vacuum pumping to obtain a yellowish-brown solid bipyrimidine nitro compound;
wherein the molar ratio of the bis-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diazapentadiene hexafluorophosphate to the nitrobenzamidine hydrochloride and sodium methoxide is 1: 5: 6; DMSO in CH3ONa/CH3OH, DMSO and CH3the mass fraction of the OH mixed solution is 75 percent;
(5) Under the protection of nitrogen, dissolving a dipyrimidine nitro compound and Pd/C in tetrahydrofuran, heating to reflux, slowly dripping hydrazine hydrate with the mass fraction of 80%, continuously refluxing for 8 hours after dripping, carrying out suction filtration while hot, carrying out rotary evaporation on filtrate, washing the obtained solid with water and absolute ethyl alcohol in sequence, and carrying out vacuum pumping to obtain yellow crystals, namely dipyrimidine diamine;
Wherein the mass ratio of the dipyrimidine nitro compound to Pd/C is 4: 1; the volume ratio of the bipyrimidine nitro compound to tetrahydrofuran is 1: 8-1: 12; the volume ratio of 80% hydrazine hydrate to the dipyrimidine nitro compound is 5: 1;
(6) adding salicylic acid into a clean reaction container, introducing nitrogen for protection, heating to enable the salicylic acid to be in a molten state, then adding the bipyrimidine diamine and dianhydride monomer obtained in the step (5) at 180 ℃, adding a small molecular substance, and carrying out sealed stirring reaction for 5 hours to obtain a viscous polyimide spinning solution;
Wherein the molar ratio of the bispyrimidine diamine to the dianhydride monomer is 1:1, and the sum of the weight of the bispyrimidine diamine and the dianhydride monomer accounts for 15 percent of the total weight of the polyimide spinning solution; the added micromolecular substance is one or a mixture of more of isoquinoline, acetic anhydride, triethylamine and pyridine, and the adding amount of the micromolecular substance is 0.1-3% of the total weight of the obtained polyimide spinning solution;
The dianhydride monomer is 1,2,4, 5-pyromellitic dianhydride;
(7) standing and defoaming the polyimide spinning solution, then carrying out wet spinning or dry-wet spinning, solidifying, washing with water, and then winding to obtain the bipyrimidine ring-containing polyimide nascent fiber; wherein the temperature of spinning solution in wet spinning or dry-wet spinning is 150 ℃, the diameter of a spinneret orifice is 0.2mm, the length-diameter ratio is 6:1, and the winding speed is 30 m/min; the solidification is that the mixture passes through a section of 50mm air bath or directly enters a solidification bath groove with the length of 2m for solidification; the water washing is carried out by a 50 ℃ water washing tank, the coagulating bath is one or a mixture of deionized water, methanol, ethanol and acetone, and the temperature is 60 ℃;
(8) Drying the polyimide nascent fiber containing the bipyrimidine ring at 100 ℃ for 2h, and then carrying out hot stretching on the polyimide nascent fiber through a hot pipe with the length of 2m to obtain the polyimide fiber; wherein the feeding speed of the polyimide fiber in the hot stretching process is 30m/min, the stretching ratio is 6 times, and the stretching temperature is 400 ℃.
test method
the polyimide fibers obtained in examples 1 to 6 were tested according to the following methods:
(1) Measurement of thermal decomposition temperature:
a WRT-3P thermogravimetric analyzer (Beijing technology Co., Ltd.) was used, the temperature rise rate was 15 ℃/min, and the test atmosphere was air.
(2) And (3) measuring the tensile property:
Measured in a CMT8102 micro-control electronic universal tester (Shenzhen New Miss materials testing Co., Ltd.) according to GB/T1042-1992.
the test results are shown in Table 1.
TABLE 1
As can be seen from the above data, the polyimide fiber obtained in the present application has excellent heat resistance and high strength, thus providing the advantageous technical effects of the present invention.
The foregoing examples are illustrative only, and serve to explain some of the features of the present disclosure. The appended claims are intended to claim as broad a scope as is contemplated, and the examples presented herein are merely illustrative of selected implementations in accordance with all possible combinations of examples. Accordingly, it is applicants' intention that the appended claims are not to be limited by the choice of examples illustrating features of the invention. And that advances in science and technology will result in possible equivalents or sub-substitutes not currently contemplated for reasons of inaccuracy in language representation, and such changes should also be construed where possible to be covered by the appended claims.

Claims (1)

1. A polyimide containing a bipyrimidine ring has a structural general formula:
wherein n is 10-1000, Ar is at least one of the following structural units:
The preparation method of the polyimide containing the bipyrimidine ring comprises the following steps:
(1) Putting the p-nitrobenzonitrile and anhydrous methanol into a dry 500ml reactor, and adding CH while stirring3ONa/CH3stirring the OH solution at room temperature for 5-10 h, and adding acetic acid to neutralize CH in the system3ONa, stirring for 30min, adding NH4cl, controlling the temperature to be 35-40 ℃, reacting for 8-20 h at the temperature, cooling to room temperature, evaporating methanol to obtain a solid, repeatedly washing the solid with acetone, and performing vacuum pumping to obtain beige solid p-nitrobenzamidine hydrochloride;
Wherein the molar ratio of the p-nitrobenzonitrile to the ammonium chloride, the sodium methoxide and the acetic acid is (15-20): (12-18): (1-3): 1, the volume ratio of the organic solvent anhydrous methanol to the p-nitrobenzonitrile is 7: 1-9: 1, CH3ONa in CH3ONa/CH3the mass fraction of the OH solution is 30-65%;
(2) placing p-phenylenediacetic acid and a polar organic solvent into a dry 500ml reactor, and slowly dripping POCl in the stirring process3controlling the temperature to be below 70 ℃ in the dripping process, controlling the temperature to be 65-70 ℃ after dripping is finished, reacting for 1-5 h, and cooling to room temperature;
Wherein the p-phenylenediacetic acid and POCl3In a molar ratio of 1: 3-1: 5; the volume ratio of the organic solvent with high polarity to the p-phenylenediacetic acid is 10: 1-15: 1;
(3) Placing sodium hydroxide and distilled water in a dry 500ml reactor, mechanically stirring in a low-temperature reaction bath, after the temperature is reduced to below 0 ℃, adding hexafluorophosphoric acid, reacting for 0.5h, dropwise adding the solution obtained in the step (2) into a reaction system, controlling the temperature to be below 10 ℃, continuing to react for 1-3 h after the dropwise adding is finished, after the reaction is finished, carrying out suction filtration, repeatedly washing a filter cake with water, carrying out vacuum drying to obtain a yellow solid, dissolving the solid in a mixed solution of THF and DMF, carrying out suction filtration, pouring distilled water into a filtrate, continuously stirring until no solid is separated out, carrying out suction filtration, and carrying out vacuum drying to obtain an orange-yellow solid di-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diaza pentadiene hexafluorophosphate;
wherein the molar ratio of the sodium hydroxide to the hexafluorophosphoric acid is 1: 1-5: 1; the mass-volume ratio of the sodium hydroxide to the distilled water is 1: 10-1: 15; the volume ratio of the THF and DMF mixed solution to the hexafluorophosphoric acid is 3: 1-10: 1;
(4) bis-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diaza-pentadiene hexafluorophosphate, p-nitrobenzamidine hydrochloride and DMSO were placed in a dry 500ml reactor, stirred to form a suspension, and CH was slowly dropped thereinto at room temperature3ONa/CH3OH, DMSO and CH3after the dripping of the mixed solution of OH, controlling the temperature of a reaction system at 70-75 ℃, continuously reacting for 9 hours, then cooling the reaction system to room temperature, carrying out suction filtration, washing the solid with water and methanol for 3 times in sequence, and carrying out vacuum pumping to obtain a yellowish-brown solid bipyrimidine nitro compound;
wherein the molar ratio of the bis-N, N, N ', N' -tetramethyl-3-phenyl-1, 5-diazapentadiene hexafluorophosphate to the p-nitrobenzamidine hydrochloride and the sodium methoxide is 1: (1-5): (1-6); DMSO in CH3ONa/CH3OH, DMSO and CH3The mass fraction of the OH mixed solution is 70-85%;
(5) Under the protection of nitrogen, dissolving a dipyrimidine nitro compound and Pd/C in tetrahydrofuran, heating until reflux, slowly dripping hydrazine hydrate, continuously refluxing for 5-10 h after dripping, carrying out suction filtration while hot, carrying out rotary evaporation on filtrate, washing the obtained solid with water and absolute ethyl alcohol in sequence, and then carrying out vacuum pumping to obtain yellow crystals, namely dipyrimidine diamine;
wherein the mass ratio of the dipyrimidine nitro compound to Pd/C is 3: 1-5: 1; the volume ratio of the bipyrimidine nitro compound to tetrahydrofuran is 1: 8-1: 12;
(6) Adding salicylic acid into a clean reaction container, introducing nitrogen for protection, heating to enable the salicylic acid to be in a molten state, then adding the bipyrimidine diamine and dianhydride monomer obtained in the step (5) at 160-210 ℃, adding a small molecular substance, and carrying out sealed stirring reaction for 1-24 hours to obtain a viscous polyimide spinning solution;
Wherein the molar ratio of the bispyrimidine diamine to the dianhydride monomer is 1:1, and the sum of the weight of the bispyrimidine diamine and the dianhydride monomer accounts for 10-25% of the total weight of the polyimide spinning solution; the added micromolecular substance is one or a mixture of more of isoquinoline, acetic anhydride, triethylamine and pyridine, and the adding amount of the micromolecular substance is 0.1-3% of the total weight of the obtained polyimide spinning solution;
The dianhydride monomer is at least one of 4, 4' - (hexafluoroisopropylidene) diphthalic anhydride and bisphenol A type diether dianhydride;
(7) standing and defoaming the polyimide spinning solution, then carrying out wet spinning or dry-wet spinning, solidifying, washing with water, and then winding to obtain the bipyrimidine ring-containing polyimide nascent fiber; wherein the temperature of spinning solution in wet or dry-wet spinning is 150 ℃, the diameter of a spinneret orifice is 0.02-0.6 mm, the length-diameter ratio is 2-8: 1, and the winding speed is 2-50 m/min; the solidification is carried out by passing through a section of 5-50 mm air bath or directly entering a solidification bath with the length of 1-3 m for solidification; the water washing is carried out by a water washing tank at the temperature of 30-80 ℃, the coagulating bath is one or a mixture of deionized water, methanol, ethanol and acetone, and the temperature is 50-100 ℃;
(8) Drying the polyimide nascent fiber containing the bipyrimidine ring at 90-110 ℃ for 1-3 h, and then carrying out hot stretching on the polyimide nascent fiber through a heat pipe with the length of 1-5 m to obtain the polyimide fiber; wherein the feeding speed of the polyimide fiber in the thermal stretching process is 4-50 m/min, the stretching ratio is 6 times, and the stretching temperature is 350-550 ℃;
the organic solvent with large polarity in the step (2) is one or more of DMAC, DMF, DMSO and N-methylpyrrolidone;
the volume ratio of THF to DMF in the THF and DMF mixed solution in the step (3) is 0.5: 1-2: 1;
CH described in step (4)3ONa in CH3ONa/CH3The mass fraction of the OH solution is 30-65%;
in the step (5), the hydrazine hydrate is 80% by mass;
in the step (5), the volume ratio of 80% hydrazine hydrate to the dipyrimidine nitro compound is 3: 1-6: 1.
CN201611076066.4A 2016-11-29 2016-11-29 Polyimide containing bipyrimidine ring and preparation method thereof Active CN106589372B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201611076066.4A CN106589372B (en) 2016-11-29 2016-11-29 Polyimide containing bipyrimidine ring and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201611076066.4A CN106589372B (en) 2016-11-29 2016-11-29 Polyimide containing bipyrimidine ring and preparation method thereof

Publications (2)

Publication Number Publication Date
CN106589372A CN106589372A (en) 2017-04-26
CN106589372B true CN106589372B (en) 2019-12-17

Family

ID=58593933

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201611076066.4A Active CN106589372B (en) 2016-11-29 2016-11-29 Polyimide containing bipyrimidine ring and preparation method thereof

Country Status (1)

Country Link
CN (1) CN106589372B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107056711B (en) * 2017-05-11 2020-07-07 吉林大学 Diamine monomer containing pyridazine group and preparation method and application thereof

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU858316A1 (en) * 1979-12-17 1985-11-30 Новосибирский институт органической химии СО АН СССР 2,5-di-(n-aminophenyl)pyramidine as monomer for synthesis of polymides,method of producing same and polyimides on its base as heat resistant material
CN103102488A (en) * 2013-02-07 2013-05-15 江西师范大学 High dielectric constant polyimide containing bipyrimidine structure and preparation method
CN103113309A (en) * 2013-02-07 2013-05-22 江西师范大学 Bipyrimidyl dibenzene/diether/diamine and synthesis method thereof
CN105671671A (en) * 2016-01-25 2016-06-15 东华大学 Preparation method of polyimide fibers containing symmetric bispyrimidine structures

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SU858316A1 (en) * 1979-12-17 1985-11-30 Новосибирский институт органической химии СО АН СССР 2,5-di-(n-aminophenyl)pyramidine as monomer for synthesis of polymides,method of producing same and polyimides on its base as heat resistant material
CN103102488A (en) * 2013-02-07 2013-05-15 江西师范大学 High dielectric constant polyimide containing bipyrimidine structure and preparation method
CN103113309A (en) * 2013-02-07 2013-05-22 江西师范大学 Bipyrimidyl dibenzene/diether/diamine and synthesis method thereof
CN105671671A (en) * 2016-01-25 2016-06-15 东华大学 Preparation method of polyimide fibers containing symmetric bispyrimidine structures

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
高强度含嘧啶环聚酰亚胺纳米纤维的制备及其应用;陈娟等;《 中国化学会第26届学术年会纳米化学分会场论文集》;20080731;第100页 *
高强高模聚酰亚胺纳米纤维的合成及其性能研究;何云云;《中国优秀硕士学位论文全文数据库工程科技Ⅰ辑》;20150315(第03期);第B016-347页 *

Also Published As

Publication number Publication date
CN106589372A (en) 2017-04-26

Similar Documents

Publication Publication Date Title
US9011739B2 (en) Methods of continuously manufacturing polymide fibers
CN107574504B (en) Polyimide/titanium dioxide hybridized fiber
CN103483206A (en) Diamine monomer containing asymmetric and non-coplanar structure, and preparation method of diamine monomer
CN105085910B (en) Inherent flame retardant bio-based benzoxazine colophony and preparation method thereof
CN103846022A (en) Preparation method of copolyimide hollow fiber gas separation membrane
CN101007778A (en) Chain-prolonged type fluorenyl bimaleimide and its preparation method
CN105670420A (en) Ultrathin steel structural fireproof anti-radiation coating
CN103922989B (en) Pyrrole radicals aromatic diamines of phthalonitrile structure and its preparation method and application
CN112275147B (en) Self-polymerization microporous polyimide gas separation membrane and preparation method and application thereof
CN103846023A (en) Copolymerization polyimide gas separation membrane material, preparation method and application of copolymerization polyimide gas separation membrane material
CN114507345B (en) Gallic acid bio-based polyimide and preparation and application thereof
CN106589372B (en) Polyimide containing bipyrimidine ring and preparation method thereof
CN108084101B (en) Melamine polyphosphate and preparation method thereof
CN101774973B (en) Polyamine containing triazole ring and preparation method and application thereof
CN109293648A (en) Benzoxazine monomer containing ethynyl and norbornene, preparation method and application thereof
CN106518926B (en) A kind of preparation method of the water-soluble benzoxazine compound containing DOPO
Tundidor-Camba et al. Aromatic polyimides containing cyclopropylamide fragment as pendant group. A study of the balance between solubility and structural rigidity
CN107417916B (en) Polyimide resin and preparation method thereof
CN103113309B (en) Bipyrimidyl dibenzene/diether/diamine and synthesis method thereof
CN106496529A (en) A kind of low-k diacetylene polymer, Its Preparation Method And Use
CN115178112B (en) Polyimide gas separation membrane containing spirobisindene bisbenzoxazole and preparation method thereof
CN102086181A (en) Synthesis method of 2,2'-diaryl-4,4',5,5'-biphenyl tetraacid dianhydride monomer
CN104262233A (en) Phthalimide-containing phthalonitrile monomer and its preparation method and use
CN109054017B (en) Hyperbranched polyimide containing phenanthrene ring structure and preparation method and application thereof
CN108003312B (en) Main chain type polybenzoxazine containing amide and imide structures and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant
TR01 Transfer of patent right

Effective date of registration: 20240327

Address after: No. 666B Chaoqun Street, High tech Development Zone, Changchun City, Jilin Province, 130015

Patentee after: CHANGCHUN HIPOLYKING Co.,Ltd.

Country or region after: China

Address before: 330096 No.99 Ziyang Avenue, Nanchang City, Jiangxi Province

Patentee before: Jiangxi Normal University

Country or region before: China

TR01 Transfer of patent right