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CN-121975114-A - Novel polyimide and preparation method thereof

CN121975114ACN 121975114 ACN121975114 ACN 121975114ACN-121975114-A

Abstract

The invention provides novel polyimide and a preparation method thereof, and belongs to the technical field of high polymer materials. The method synthesizes 1, 4-disubstituted 1,2, 3-triazole through copper-catalyzed azido-alkyne cycloaddition reaction in click chemistry, takes 1, 4-disubstituted 1,2, 3-triazole as diamine monomer to react with dianhydride monomer to prepare polyimide, the process route has easily obtained raw materials, simple and convenient reaction operation, high reaction efficiency and mild reaction condition, the method has the advantages of simplicity and modularization, does not need complicated protection and deprotection steps, provides an extensible, economical and feasible synthesis strategy for developing high-performance polyimide, and is particularly suitable for large-scale industrial preparation requirements in high-end fields such as aerospace, electronic packaging and the like; in addition, the polyimide prepared by the method has good thermal stability, the glass transition temperature is more than 320 ℃, and the high-temperature resistant performance requirement of the polyimide material in the fields of aerospace and electronic packaging can be met.

Inventors

  • CHEN WENDUO
  • FENG ZHIJIE
  • WENG LINGKAI
  • ZHAO HONGCHAO
  • WANG SHIJIE
  • Ye langlang
  • ZHUO ZHILANG

Assignees

  • 中山大学

Dates

Publication Date
20260505
Application Date
20260319

Claims (10)

  1. 1. The preparation method of the novel polyimide is characterized by comprising the following steps of: S1, synthesizing 1, 4-disubstituted 1,2, 3-triazole by using 4-azidoaniline and 4-ethynylaniline as raw materials through copper-catalyzed azido-alkyne cycloaddition reaction, wherein the structural formula of the 1, 4-disubstituted 1,2, 3-triazole is as follows: ; s2, dissolving 1, 4-disubstituted 1,2, 3-triazole and dianhydride monomer in a solvent to obtain a reaction solution, stirring the reaction solution at a preset temperature to enable the reaction solution to undergo polycondensation reaction to obtain polyamic acid, heating the polyamic acid to imidize the polyamic acid to obtain polyimide, wherein the polyimide has the structural formula: ; wherein R represents a reaction residue of a dianhydride monomer.
  2. 2. The method for producing a novel polyimide according to claim 1, wherein the dianhydride monomer is pyromellitic dianhydride or 3,3', 4' -biphenyl tetracarboxylic dianhydride.
  3. 3. The method for preparing a novel polyimide according to claim 1, wherein the step S1 specifically comprises: s11, dissolving 4-azidoaniline and 4-ethynyl aniline in a mixed solvent under an inert atmosphere to obtain a first solution, wherein the mixed solvent comprises water and tertiary butanol; S12, adding a catalytic amount of an aqueous solution of ascorbate and copper salt (II) into the first solution to obtain a second solution; S13, stirring the second solution at the temperature of 20-100 ℃ for reaction for a preset period of time; S14, adding an organic extraction solvent and an adsorption carrier into the second solution after the reaction is finished, concentrating the second solution under reduced pressure to remove the solvent to obtain a solid, purifying the obtained solid by silica gel column chromatography, collecting a target component, and drying the target component to obtain the 1, 4-disubstituted 1,2, 3-triazole.
  4. 4. The method for producing a novel polyimide according to claim 3, wherein in the step S11, the molar ratio of the 4-azidoaniline to the 4-ethynylaniline is 1 (0.5 to 2.5), and the volume ratio of water to t-butanol in the mixed solvent is 1 (0.5 to 3).
  5. 5. The method according to claim 3, wherein in the step S12, the ascorbate is used in an amount of 0.05 to 0.5 equivalent to the molar amount of 4-azidobenzolamide in the step S11, and the copper (II) salt is used in an amount of 0.005 to 0.05 equivalent to the molar amount of 4-azidobenzolamide.
  6. 6. The method for preparing a novel polyimide according to claim 1, wherein the 4-azidobenzolamide is prepared by the steps of: S100, under inert atmosphere, dissolving cuprous iodide, sodium hydroxide and sodium ascorbate in water in the same reaction container to obtain a catalytic system; S200, dropwise adding trimethyl silane azide and ethylenediamine into the catalytic system at the temperature of-20-30 ℃; S300, dropwise adding a dimethyl sulfoxide solution of 4-amino iodobenzene into the catalytic system to obtain a reaction system, wherein the reaction system reacts for a preset period of time at 0-60 ℃; s400, adding ethyl acetate into a reaction system after reaction for extraction, washing an extraction product with water and saturated sodium chloride aqueous solution in sequence until an organic phase and an aqueous phase are clear, and then drying the obtained organic phase with anhydrous magnesium sulfate; S500, purifying the dried organic phase by silica gel column chromatography to obtain the 4-azidoaniline.
  7. 7. The method for preparing polyimide according to claim 6, wherein the molar ratio of the cuprous iodide, sodium hydroxide and sodium ascorbate in the step S100 is 1 (10-30) (0.1-1.0).
  8. 8. The method of producing a novel polyimide according to claim 6, wherein the molar ratio of the azido trimethylsilane to ethylenediamine used in step S200 is (20-50): 1.
  9. 9. The method according to claim 6, wherein in the step S300, the concentration of 4-amino iodobenzene in the dimethyl sulfoxide solution of 4-amino iodobenzene is 0.1-0.5 g/ml.
  10. 10. A polyimide produced by the process for producing a novel polyimide according to any one of claims 1 to 9.

Description

Novel polyimide and preparation method thereof Technical Field The invention relates to the technical field of high polymer materials, in particular to novel polyimide and a preparation method thereof. Background Polyimide is a polymer containing imide ring (-CO-NH-CO-) on the main chain, has the advantages of high temperature resistance, good mechanical property, excellent electrical insulation property, radiation resistance, good chemical stability and the like, is widely applied to the fields of aerospace, electronic packaging, medical equipment, automobile industry and the like, and particularly with the rapid development of high-performance aeroengine technology in recent years, resin-based composite materials are increasingly used for replacing metal materials to achieve the purpose of light weight, wherein polyimide has important application value in the field of aerospace due to the advantages of high temperature resistance, excellent mechanical property and the like. The synthesis of polyimide is usually completed through polycondensation reaction, namely dianhydride monomer and diamine monomer are subjected to polycondensation reaction in a proper solvent to generate a polyamic acid intermediate, then the polyamic acid is converted into polyimide through chemical or heat treatment, the molecular structure of polyimide can be regulated and controlled through selecting monomer combinations containing different functional groups due to the diversity of the monomers, and further the thermal stability, mechanical properties and other properties of polyimide films are regulated and controlled to meet specific requirements, however, the conventional method usually depends on multi-step synthesis, complex catalyst or protecting group strategies when special functional groups are introduced to improve the material properties (such as heat resistance and dielectric properties), and the reaction route is long, the process control is complex, the cost is increased and the mass production is difficult. Disclosure of Invention The invention provides a novel polyimide and a preparation method thereof, which are suitable for mass production of high-performance polyimide. The preparation method of the novel polyimide provided by the invention comprises the following steps: S1, synthesizing 1, 4-disubstituted 1,2, 3-triazole by using 4-azidoaniline and 4-ethynylaniline as raw materials through copper-catalyzed azido-alkyne cycloaddition reaction, wherein the structural formula of the 1, 4-disubstituted 1,2, 3-triazole is as follows: ; s2, dissolving 1, 4-disubstituted 1,2, 3-triazole and dianhydride monomer in a solvent to obtain a reaction solution, stirring the reaction solution at a preset temperature to enable the reaction solution to undergo polycondensation reaction to obtain polyamic acid, heating the polyamic acid to imidize the polyamic acid to obtain polyimide, wherein the polyimide has the structural formula: ; wherein R represents a reaction residue of a dianhydride monomer. Alternatively, the dianhydride monomer is pyromellitic dianhydride (PMDA) or 3,3', 4' -biphenyl tetracarboxylic dianhydride (BPDA). Optionally, the temperature of the polycondensation reaction is 10-80 ℃ and the reaction time is 5-20 h. Alternatively, the polyamic acid was vacuum defoamed for a period of 0.5 hours. Optionally, the preset curing procedure is a step-heating curing procedure, specifically 100 ℃ for 60 minutes, 200 ℃ for 60 minutes, 300 ℃ for 60 minutes and 320 ℃ for 60 minutes, and finally at an imidization temperature of 30 minutes, and the imidization temperature is 310-330 ℃. Optionally, the feeding mole ratio of the dianhydride monomer to the 1, 4-disubstituted 1,2, 3-triazole is 1 (1-1.5), the mass ratio of the total mass of the dianhydride monomer to the diamine monomer to the solvent is 1 (8-15), and the aprotic solvent is selected as the solvent for dissolving the dianhydride monomer and the diamine monomer. Alternatively, the solvent for the polycondensation reaction is dimethyl sulfoxide. Optionally, after heating the substrate with a preset curing procedure to imidize the polyamic acid, cooling the substrate, and then performing hot water stripping treatment to obtain a polyimide film, wherein the thickness of the polyimide film is 150-300 μm. The step S1 of synthesizing the 1, 4-disubstituted 1,2, 3-triazole through copper-catalyzed azide-alkyne cycloaddition reaction specifically comprises the following steps: s11, dissolving 4-azidoaniline and 4-ethynyl aniline in a mixed solvent under an inert atmosphere to obtain a first solution, wherein the mixed solvent comprises water and tertiary butanol; S12, adding a catalytic amount of an aqueous solution of ascorbate and copper salt (II) into the first solution to obtain a second solution; S13, stirring the second solution at the temperature of 20-100 ℃ for reaction for a preset period of time; S14, adding an organic extraction solvent and an adsorption carrier