CN113416346B - Method for preparing polyamic acid by microwave controllable breaking of carbon-nitrogen bond - Google Patents

Method for preparing polyamic acid by microwave controllable breaking of carbon-nitrogen bond Download PDF

Info

Publication number
CN113416346B
CN113416346B CN202110671815.2A CN202110671815A CN113416346B CN 113416346 B CN113416346 B CN 113416346B CN 202110671815 A CN202110671815 A CN 202110671815A CN 113416346 B CN113416346 B CN 113416346B
Authority
CN
China
Prior art keywords
polyamic acid
preparing
microwave
reaction
carbon
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
CN202110671815.2A
Other languages
Chinese (zh)
Other versions
CN113416346A (en
Inventor
侯相林
田梓赏
王玉琪
毛昳萱
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.)
Shanxi Institute of Coal Chemistry of CAS
Original Assignee
Shanxi Institute of Coal Chemistry of CAS
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 Shanxi Institute of Coal Chemistry of CAS filed Critical Shanxi Institute of Coal Chemistry of CAS
Priority to CN202110671815.2A priority Critical patent/CN113416346B/en
Publication of CN113416346A publication Critical patent/CN113416346A/en
Application granted granted Critical
Publication of CN113416346B publication Critical patent/CN113416346B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J11/00—Recovery or working-up of waste materials
    • C08J11/04—Recovery or working-up of waste materials of polymers
    • C08J11/10—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2379/00—Characterised by the use of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen with or without oxygen, or carbon only, not provided for in groups C08J2361/00 - C08J2377/00
    • C08J2379/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
    • C08J2379/08—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
    • Y02W30/50—Reuse, recycling or recovery technologies
    • Y02W30/62—Plastics recycling; Rubber recycling

Landscapes

  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Macromolecular Compounds Obtained By Forming Nitrogen-Containing Linkages In General (AREA)

Abstract

The invention provides a method for preparing polyamic acid by microwave controllable breaking of carbon-nitrogen bonds, which comprises the following steps: polyimide resin, solvent and alkaline catalyst are prepared into a degradation system, and the degradation system is placed in a microwave reactor for degradation reaction. After the degradation, the solvent is distilled off and the acid is strengthened to obtain the polyamic acid. The method selectively breaks carbon-nitrogen bonds by using the basic catalyst under the microwave condition, controls the dosage of the catalyst to generate the polyamic acid in a controllable manner, and has the advantages of low recovery cost, mild reaction condition, normal-pressure degradation and easy separation to obtain products with high added values.

Description

Method for preparing polyamic acid by controllably breaking carbon-nitrogen bonds through microwaves
Technical Field
The invention belongs to the field of recycling and resource utilization of waste high polymer materials, and particularly relates to a method for preparing polyamic acid by microwave-controlled breaking of carbon-nitrogen bonds.
Background
The polyimide resin is a polymer with an imide group (CO-N-CO) -in a main chain, is used for preparing microelectronic devices such as flexible circuit boards, is used as a dielectric layer for interlayer insulation, and can reduce stress and improve yield when used as a buffer layer; in the aerospace, aircraft and military fields, polyimide resin is the highest temperature resistant structural material.
The polyamic acid is a high polymer material which has the advantages of high temperature resistance, low temperature resistance, radiation resistance, chemical corrosion resistance, strong adhesive force, good flexibility, excellent mechanical property, impact resistance, fire prevention, non-combustion and environmental protection. The imidization of the polyamic acid is relatively complete, and the tensile strength of the PMDA-PDA polyimide film reaches 290MPa, so the polyamic acid is an important raw material for preparing the polyimide resin. The preparation of polyamic acid (PAA) by controlled cleavage of carbon nitrogen bonds of waste Polyimide (PI) resins is an economically very efficient process.
The microwave reaction has the advantages of high heating speed, high heating efficiency, electricity and energy conservation, uniform heating and instant control of the heating process. The temperature rise generated in the microwave heating process for materials with different substances or different water contents is different, and the larger the water content is, the faster the heating is; conversely, the slower the speed. The microwave degradation can be carried out at normal pressure, the reaction condition is mild, and the method is an environment-friendly, energy-saving and efficient mode.
Disclosure of Invention
The invention provides a method for preparing polyamic acid by controllably breaking carbon-nitrogen bonds by microwaves, aiming at solving the technical problem of recycling polyimide resin.
In order to realize the purpose, the invention is realized by the following technical scheme:
a method for preparing polyamic acid by microwave controllable breaking of carbon-nitrogen bonds comprises the following steps:
preparing a solvent and an alkaline catalyst into a reaction system I according to a proportion, mixing the waste polyimide resin and the reaction system I according to a proportion, filling the mixture into a round-bottom flask, connecting a reflux device, and placing the reaction system I into a microwave reactor for heating reaction; and cooling to room temperature after the reaction is finished to obtain a polyamic acid salt solution, performing rotary evaporation on the polyamic acid salt solution, and adding acid to obtain the polyamic acid solution.
According to the method, a carbon-nitrogen bond is selectively broken by using an alkaline catalyst, and the polyimide resin is controllably degraded by controlling the molar ratio of the alkaline catalyst to a polyimide repeating unit, so that the polyamic acid is obtained. The recovery method is simple and easy to implement, and does not produce secondary pollution.
Further, the basic catalyst is any one of sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, sodium carbonate, potassium carbonate, lithium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, and trimethylethylammonium hydroxide. The catalyst selected by the scheme has a good selective breaking effect on carbon-nitrogen bonds, and the molar ratio can be changed to control the generation of different reaction products.
Still further, the solvent is water or a mixed solution of water and an organic solvent, wherein the organic solvent is any one of tetrahydrofuran, N-dimethylformamide, N-dimethylacetamide, ethylenediamine, N-methyl-2-pyrrolidone, triethylamine, toluene, m-cresol, chloroform, acetone, methanol, ethanol, and isopropanol. The solvent selected by the scheme has good swelling effect and reaction performance on the degradation of the polyimide resin.
Further, the mass ratio of the water to the organic solvent is 1: 1-10. Dissolving the catalyst in water to dissociate active group for breaking carbon-nitrogen bond; the organic reagent is used for improving the wettability of the degradation system and the polyimide resin and dissolving degradation products.
Furthermore, the mass fraction of the basic catalyst in the reaction system I is 1-10%; the molar ratio of the polyimide repeating unit to the basic catalyst is 1: 1-10. Within the range of the technical scheme, the degradation of the polyimide resin is sufficient. When the mass fraction of the catalyst is too small, the concentration of the catalyst is too low to exert its catalytic effect. When the mass fraction of the catalyst is too large, most of the degradation products are small molecular monomers, unnecessary waste is caused, and the subsequent separation step is not facilitated.
Furthermore, the power of the microwave reactor is 100-800W, and the reaction time is 1-5 h. Within the range of the technical scheme, the polyimide resin can be fully degraded. When the power of the microwave reactor is lower than 100W, the degradation reaction basically does not occur; when the microwave reactor power is higher than 800W, side reactions occur. When the reaction time is less than 1h, the polyimide resin can be only partially degraded; when the reaction time is more than 5 hours, energy waste is caused and the reaction period is prolonged.
Still further, the acid is hydrochloric acid or sulfuric acid. According to the technical scheme, strong acid is selected for acidification, so that polyamic acid salt can directly react to generate polyamic acid.
Furthermore, the molar ratio of the acid to the polyimide resin in the reaction system I is 1-10: 1.
Further, the structure of the waste polyimide resin is as follows:
Figure BDA0003119639810000031
wherein Ar is1The structure comprises the following structures:
Figure BDA0003119639810000032
Ar2the structure comprises the following structures:
Figure BDA0003119639810000033
compared with the prior art, the invention has the following beneficial effects:
(1) the controllable degradation of the polyimide resin is realized by selectively breaking carbon-nitrogen bonds, and the recovery has
The reaction mechanism of the high value-added polyamic acid is as follows:
Figure BDA0003119639810000041
(2) the reaction process has relatively mild conditions, high reaction rate, simple and feasible recovery method and no secondary pollution.
Drawings
FIG. 1 is an infrared spectrum of the recovered polyamic acid.
Detailed Description
The following examples are given in the detailed description and the specific operation on the premise of the technical solutions of the present invention, but do not limit the protection scope of the patent of the present invention, and all technical solutions obtained by using equivalent alternatives or equivalent variations should fall within the protection scope of the present invention.
Example 1
In this embodiment, a method for preparing polyamic acid by microwave-controlled breaking of carbon-nitrogen bonds includes the following steps:
preparing a reaction solvent from water and N-methyl-2-pyrrolidone according to a mass ratio of 1:2.5, preparing a reaction system I from the reaction solvent and sodium hydroxide according to a mass fraction of 1% of the catalyst, mixing the polyimide resin and the reaction system I, adding the mixture into a round-bottom flask, connecting a reflux device, placing the flask into a microwave reactor, heating, and reacting for 5 hours at 100W, wherein the molar ratio of the polyimide resin to the catalyst is 1: 10. Cooling to room temperature after the reaction is finished to obtain polyamic acid salt solution, performing rotary evaporation on the polyamic acid salt solution, and adding hydrochloric acid according to the molar ratio of the acid to the polyimide resin repeating unit of 10:1 to obtain polyamic acid solution with certain viscosity, wherein an infrared spectrogram of the polyamic acid solution is shown in figure 1.
Example 2
In this embodiment, a method for preparing polyamic acid by microwave-controlled breaking of carbon-nitrogen bonds includes the following steps:
preparing a reaction solvent from water and tetrahydrofuran according to a mass ratio of 1:1, preparing a reaction system I from the reaction solvent and tetramethylammonium hydroxide according to a mass fraction of 2% of a catalyst, mixing the polyimide resin and the reaction system I, adding the mixture into a round-bottom flask, connecting a reflux device, heating the mixture in a microwave reactor, and reacting for 4 hours at 200W, wherein the molar ratio of the polyimide resin repeating unit to the catalyst is 1: 5. And cooling to room temperature after the reaction is finished to obtain a polyamic acid salt solution, performing rotary evaporation on the polyamic acid salt solution, and adding sulfuric acid according to the molar ratio of the acid to the polyimide resin repeating unit of 5:1 to obtain the polyamic acid solution with certain viscosity.
Example 3
In this embodiment, a method for preparing polyamic acid by microwave-controlled breaking of carbon-nitrogen bonds includes the following steps:
preparing a reaction system from water and ethylenediamine according to a mass ratio of 1:10, wherein the molar ratio of the polyimide resin repeating unit to the ethylenediamine catalyst is 1:2, mixing the polyimide resin and the reaction system, adding the mixture into a round-bottom flask, connecting a reflux device, heating the mixture in a microwave reactor, and reacting for 3 hours at 300W. And cooling to room temperature after the reaction is finished to obtain a polyamic acid salt solution, carrying out rotary evaporation on the polyamic acid salt solution, and adding hydrochloric acid according to the molar ratio of the acid to the polyimide resin repeating unit of 2:1 to obtain a polyamic acid solution with certain viscosity.
Example 4
In this embodiment, a method for preparing polyamic acid by microwave-controlled breaking of carbon-nitrogen bonds includes the following steps:
preparing a reaction system from water and triethylamine according to the mass ratio of 1:2, wherein the molar ratio of the polyimide resin repeating unit to the triethylamine catalyst is 1:6, mixing the polyimide resin and the reaction system, adding the mixture into a round-bottom flask, connecting a reflux device, heating the mixture in a microwave reactor, and reacting for 2 hours at 400W. And cooling to room temperature after the reaction is finished to obtain a polyamic acid salt solution, performing rotary evaporation on the polyamic acid salt solution, and adding hydrochloric acid according to the molar ratio of the acid to the polyimide resin repeating unit of 6:1 to obtain the polyamic acid solution with certain viscosity.
Example 5
In this embodiment, a method for preparing polyamic acid by microwave-controlled breaking of carbon-nitrogen bonds includes the following steps:
preparing a reaction solvent from water and N, N-dimethylacetamide according to a mass ratio of 1:3, preparing a reaction system I from the reaction solvent and rubidium hydroxide according to a mass fraction of 3% of a catalyst, wherein the molar ratio of a polyimide resin repeating unit to the catalyst is 1:7, mixing the polyimide resin and the reaction system, adding the mixture into a round-bottom flask, connecting a reflux device, heating the mixture in a microwave reactor, and reacting for 5 hours at 500W. And cooling to room temperature after the reaction is finished to obtain a polyamic acid salt solution, performing rotary evaporation on the polyamic acid salt solution, and adding hydrochloric acid according to the molar ratio of the acid to the polyimide resin repeating unit of 8:1 to obtain a polyamic acid precipitate with a certain viscosity.
Example 6
In this embodiment, a method for preparing polyamic acid by microwave-controlled breaking of carbon-nitrogen bonds includes the following steps:
preparing a reaction solvent from water and N, N-dimethylformamide according to a mass ratio of 1:4, preparing a reaction system I from the reaction solvent and potassium hydroxide according to a mass fraction of 4% of a catalyst, wherein the molar ratio of a polyimide resin repeating unit to the catalyst is 1:6, mixing the polyimide resin and the reaction system, adding the mixture into a round-bottom flask, connecting a reflux device, heating the mixture in a microwave reactor, and reacting for 4 hours at 600W. And cooling to room temperature after the reaction is finished to obtain a polyamic acid salt solution, performing rotary evaporation on the polyamic acid salt solution, and adding sulfuric acid according to the molar ratio of the acid to the polyimide resin repeating unit of 6:1 to obtain the polyamic acid solution with certain viscosity.
Example 7
In this embodiment, a method for preparing polyamic acid by microwave-controlled breaking of carbon-nitrogen bonds includes the following steps:
preparing a reaction solvent from water and toluidine according to a mass ratio of 1:5, preparing a reaction system I from the reaction solvent and lithium hydroxide according to a mass fraction of 5% of a catalyst, mixing the polyimide resin and the reaction system, adding the mixture into a round-bottom flask, connecting a reflux device, heating the mixture in a microwave reactor, and reacting for 2 hours at 700W, wherein the molar ratio of the polyimide resin repeating unit to the catalyst is 1: 9. And cooling to room temperature after the reaction is finished to obtain a polyamic acid salt solution, performing rotary evaporation on the polyamic acid salt solution, and adding sulfuric acid according to the molar ratio of the acid to the polyimide resin repeating unit of 9:1 to obtain the polyamic acid solution with certain viscosity.
Example 8
In this embodiment, a method for preparing polyamic acid by microwave-controlled breaking of carbon-nitrogen bonds includes the following steps:
preparing a reaction solvent from water and isopropanol according to a mass ratio of 1:6, preparing a reaction system I from the reaction solvent and cesium hydroxide according to a mass fraction of 6% of a catalyst, mixing the polyimide resin and the reaction system, adding the mixture into a round-bottom flask, connecting a reflux device, heating the mixture in a microwave reactor, and reacting for 1 hour at 800W, wherein the molar ratio of the polyimide resin repeating unit to the catalyst is 1: 10. And cooling to room temperature after the reaction is finished to obtain a polyamic acid salt solution, performing rotary evaporation on the polyamic acid salt solution, and adding sulfuric acid according to the molar ratio of the acid to the polyimide resin repeating unit of 10:1 to obtain the polyamic acid solution with certain viscosity.
Example 9
In this embodiment, a method for preparing polyamic acid by microwave-controlled breaking of carbon-nitrogen bonds includes the following steps:
preparing a reaction solvent from water and m-cresol according to a mass ratio of 2:5, preparing a reaction system I from the reaction solvent and tetraethylammonium hydroxide according to a catalyst mass fraction of 7%, wherein the molar ratio of a polyimide resin repeating unit to a catalyst is 1:4, mixing the polyimide resin and the reaction system, adding the mixture into a round-bottom flask, connecting a reflux device, then placing the flask into a microwave reactor, heating the flask, and reacting for 3 hours at 250W. And cooling to room temperature after the reaction is finished to obtain a polyamic acid salt solution, carrying out rotary evaporation on the polyamic acid salt solution, and adding sulfuric acid according to the molar ratio of the acid to the polyimide resin repeating unit of 4:1 to obtain a polyamic acid precipitate with a certain viscosity.
Example 10
In this embodiment, a method for preparing polyamic acid by microwave-controlled breaking of carbon-nitrogen bonds includes the following steps:
preparing a reaction solvent from water and trichloromethane according to a mass ratio of 1:7, preparing a reaction system I from the reaction solvent and trimethyl ethyl ammonium hydroxide according to a mass fraction of 8% of a catalyst, mixing the polyimide resin and the reaction system, adding the mixture into a round-bottom flask, connecting a reflux device, heating the mixture in a microwave reactor, and reacting for 3 hours at 350W, wherein the molar ratio of the polyimide resin repeating unit to the catalyst is 1: 8. And cooling to room temperature after the reaction is finished to obtain a polyamic acid salt solution, performing rotary evaporation on the polyamic acid salt solution, and adding sulfuric acid according to the molar ratio of the acid to the polyimide resin repeating unit of 8:1 to obtain the polyamic acid solution with certain viscosity.
Example 11
In this embodiment, a method for preparing polyamic acid by microwave-controlled breaking of carbon-nitrogen bonds includes the following steps:
preparing a reaction solvent from water and acetone according to a mass ratio of 1:8, preparing a reaction system I from the reaction solvent and lithium hydroxide according to a mass fraction of 9% of a catalyst, mixing the polyimide resin and the reaction system, adding the mixture into a round-bottom flask, connecting a reflux device, heating the mixture in a microwave reactor, and reacting for 5 hours at 450W, wherein the molar ratio of the polyimide resin repeating unit to the catalyst is 1:2. And cooling to room temperature after the reaction is finished to obtain a polyamic acid salt solution, performing rotary evaporation on the polyamic acid salt solution, and adding sulfuric acid according to the molar ratio of the acid to the polyimide resin repeating unit of 2:1 to obtain the polyamic acid solution with certain viscosity.
Example 12
In this embodiment, a method for preparing polyamic acid by microwave-controlled breaking of carbon-nitrogen bonds includes the following steps:
preparing a reaction solvent from water and methanol according to a mass ratio of 1:9, preparing a reaction system I from the reaction solvent and potassium carbonate according to a catalyst mass fraction of 10%, wherein the molar ratio of a polyimide resin repeating unit to the catalyst is 1:1, mixing the polyimide resin and the reaction system, adding the mixture into a round-bottom flask, connecting a reflux device, placing the flask into a microwave reactor, heating, and reacting for 2.5 hours at 550W. And cooling to room temperature after the reaction is finished to obtain a polyamic acid salt solution, carrying out rotary evaporation on the polyamic acid salt solution, and adding sulfuric acid according to the molar ratio of the acid to the polyimide resin repeating unit of 1:1 to obtain a polyamic acid solution with certain viscosity.
Example 13
In this embodiment, a method for preparing polyamic acid by microwave-controlled breaking of carbon-nitrogen bonds includes the following steps:
preparing a reaction solvent from water and ethanol according to a mass ratio of 1:10, preparing a reaction system I from the reaction solvent and sodium carbonate according to a mass fraction of 10% of a catalyst, mixing the polyimide resin and the reaction system, adding the mixture into a round-bottom flask, connecting a reflux device, heating the mixture in a microwave reactor, and reacting for 3.5 hours at 650W, wherein the molar ratio of the polyimide resin repeating unit to the catalyst is 1: 3. And cooling to room temperature after the reaction is finished to obtain a polyamic acid salt solution, performing rotary evaporation on the polyamic acid salt solution, and adding sulfuric acid according to the molar ratio of the acid to the polyimide resin repeating unit of 3:1 to obtain the polyamic acid solution with certain viscosity.
Example 14
In this embodiment, a method for preparing polyamic acid by microwave-controlled breaking of carbon-nitrogen bonds includes the following steps:
preparing a reaction system I from water and sodium hydroxide according to 5% of the mass fraction of a catalyst, wherein the molar ratio of a polyimide resin repeating unit to the catalyst is 1:1, mixing the polyimide resin and the reaction system, adding the mixture into a round-bottom flask, connecting a reflux device, heating the mixture in a microwave reactor, and reacting for 1 hour at 400W. And cooling to room temperature after the reaction is finished to obtain a polyamic acid salt solution, performing rotary evaporation on the polyamic acid salt solution, and adding sulfuric acid according to the molar ratio of the acid to the polyimide resin repeating unit of 3:1 to obtain the polyamic acid solution with certain viscosity.

Claims (4)

1. A method for preparing polyamic acid by microwave controllable breaking of carbon-nitrogen bonds is characterized by comprising the following steps: the method comprises the following steps:
preparing a solvent and an alkaline catalyst into a reaction system I according to a proportion, mixing the waste polyimide resin and the reaction system I according to a proportion, filling the mixture into a round-bottom flask, connecting a reflux device, and placing the reaction system I into a microwave reactor for heating reaction; cooling to room temperature after the reaction is finished to obtain a polyamic acid salt solution, performing rotary evaporation on the polyamic acid salt solution, and adding acid to obtain a polyamic acid solution;
the solvent is water or a mixed solution of water and an organic solvent, wherein the organic solvent is any one of tetrahydrofuran, N-dimethylformamide, N-dimethylacetamide, ethylenediamine, N-methyl-2-pyrrolidone, triethylamine, toluene, m-cresol, trichloromethane, acetone, methanol, ethanol and isopropanol;
the mass ratio of the water to the organic solvent is 1: 1-10;
the alkaline catalyst is any one of sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, sodium carbonate, potassium carbonate, lithium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide and trimethyl ethyl ammonium hydroxide;
the mass fraction of the alkaline catalyst in the reaction system I is 1-10%;
the molar ratio of the repeating unit of the polyimide to the basic catalyst is 1: 1-10;
the power of the microwave reactor is 100-800W, and the reaction time is 1-5 h.
2. The method for preparing polyamic acid by microwave controlled breaking of carbon-nitrogen bond according to claim 1, wherein: the acid is hydrochloric acid or sulfuric acid.
3. The method for preparing polyamic acid by microwave controlled breaking of carbon-nitrogen bond according to claim 1, wherein: the molar ratio of the acid to the repeating units of the polyimide is 1-10: 1.
4. The method for preparing polyamic acid by microwave controlled breaking of carbon-nitrogen bond according to claim 1, wherein the structure of the waste polyimide resin is as follows:
Figure FDA0003587225300000021
wherein Ar is1The structure comprises the following structures:
Figure FDA0003587225300000022
Ar2the structure comprises the following structures:
Figure FDA0003587225300000023
CN202110671815.2A 2021-06-17 2021-06-17 Method for preparing polyamic acid by microwave controllable breaking of carbon-nitrogen bond Active CN113416346B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110671815.2A CN113416346B (en) 2021-06-17 2021-06-17 Method for preparing polyamic acid by microwave controllable breaking of carbon-nitrogen bond

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110671815.2A CN113416346B (en) 2021-06-17 2021-06-17 Method for preparing polyamic acid by microwave controllable breaking of carbon-nitrogen bond

Publications (2)

Publication Number Publication Date
CN113416346A CN113416346A (en) 2021-09-21
CN113416346B true CN113416346B (en) 2022-05-31

Family

ID=77788837

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110671815.2A Active CN113416346B (en) 2021-06-17 2021-06-17 Method for preparing polyamic acid by microwave controllable breaking of carbon-nitrogen bond

Country Status (1)

Country Link
CN (1) CN113416346B (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3892716A (en) * 1971-05-28 1975-07-01 Gen Electric Method for making carboxy free polyamide acid salts derived therefrom
CN101525783A (en) * 2009-03-27 2009-09-09 苏州大学 Polyimide fiber and preparation method thereof
WO2012091424A2 (en) * 2010-12-29 2012-07-05 코오롱인더스트리 주식회사 Electronic photodegradable material, and insulating layer and organic light-emitting diode made of same
CN108929438A (en) * 2017-05-23 2018-12-04 万华化学集团股份有限公司 A kind of preparation method of polyamic acid and the method that polyimides is prepared by the polyamic acid

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3892716A (en) * 1971-05-28 1975-07-01 Gen Electric Method for making carboxy free polyamide acid salts derived therefrom
CN101525783A (en) * 2009-03-27 2009-09-09 苏州大学 Polyimide fiber and preparation method thereof
WO2012091424A2 (en) * 2010-12-29 2012-07-05 코오롱인더스트리 주식회사 Electronic photodegradable material, and insulating layer and organic light-emitting diode made of same
CN108929438A (en) * 2017-05-23 2018-12-04 万华化学集团股份有限公司 A kind of preparation method of polyamic acid and the method that polyimides is prepared by the polyamic acid

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
DEGRADATION AND STABILITY OF POLYIMIDES;CELLA, JA;《POLYMER DEGRADATION AND STABILITY》;19921231;第36卷(第2期);第99-110页 *
影响聚酰胺酸降解因素的研究;陈娆;《沈阳化工学院学报》;20020630;第16卷(第2期);第124-126页 *

Also Published As

Publication number Publication date
CN113416346A (en) 2021-09-21

Similar Documents

Publication Publication Date Title
CN110128982B (en) Normal-temperature fast-curing structural adhesive and preparation method thereof
CN101787145B (en) Method for recovering fiber from epoxy resin/fiber composite material
CN103275319B (en) Polyimide foam and preparation method thereof
CN113416346B (en) Method for preparing polyamic acid by microwave controllable breaking of carbon-nitrogen bond
CN101906196A (en) Comprehensive utilization method of phenolic resin wastewater
CN112142953A (en) Dielectric and heat conduction enhanced bio-based high-temperature-resistant epoxy resin and preparation method and application thereof
CN115142288B (en) Method for rapidly separating all components of lignocellulosic biomass by using alkaline eutectic solvent
CN104761897A (en) Modified PBO fiber/cyanate ester resin wave-transparent composite material and preparation method thereof
CN110819023B (en) Low-dielectric-loss resin-based composite material and preparation method and application thereof
CN111040132A (en) Degradable amine epoxy curing agent containing-C-N-dynamic covalent bond and preparation method thereof
CN115041511A (en) Resource utilization method of waste fiber reinforced composite material
CN105037655A (en) Carbon gold composite floor and preparation method thereof
CN106118743A (en) A kind of environmentally friendly preparation method of chlorinated paraffin
CN103554354A (en) Method for preparing high-density polymethacrylimide foam material
CN104650372A (en) Thermosetting polymer compound, poly-half-amide supermolecular film and preparation method thereof
CN112321961A (en) High-performance polystyrene toughening foam material and preparation method thereof
CN102976315A (en) Microwave-assisted method for preparing graphene through reduction of sodium citrate
CN113429623B (en) Method for preparing polyamic acid by degrading polyimide resin
CN102115547B (en) Molten bath and method for recycling thermosetting epoxy resin or composite material by using same
CN103740056A (en) Glass fiber reinforced plastic material and telegraph pole provided with glass fiber reinforced plastic sheathing plate
CN113690456B (en) High-performance graphene bipolar plate for fuel cell and preparation method thereof
CN109305896A (en) A kind of low polar resin and its preparation method and application
CN114226415A (en) Photovoltaic module separation and recovery method
CN103044705A (en) Thermosetting epoxy resin under microwave condition and degradation method of composite material of thermosetting epoxy resin in ionic liquid
CN1349962A (en) Fluorine-containing trifluorostyrene monomer and its synthesis and use

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