A kind of preparation method of chopped fiber layered reinforced polyimide airgel

A polyimide wet gel, layered reinforcement technology, applied in fiber processing, fiber types, textiles and papermaking, etc., can solve the difficulty of preparing chopped fiber reinforced polyimide aerogel composites, bonding problems such as poor performance, to achieve the effects of excellent shock absorption and noise reduction, good stability and broad application prospects

Active Publication Date: 2022-04-26
NANJING TECH UNIV +1
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] At present, chopped fiber layered reinforcement is a way to increase the impact resistance of airgel materials while maintaining the thermal insulation properties of airgel materials, but due to the faster gelation speed of polyimide wet gels, short The poor bonding between chopped fibers and airgel matrix makes the preparation of chopped fiber reinforced polyimide airgel composites more difficult, so there has never been a combination of polyimide airgel and short Related reports on layered composite of cut fiber reinforcement

Method used

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  • A kind of preparation method of chopped fiber layered reinforced polyimide airgel
  • A kind of preparation method of chopped fiber layered reinforced polyimide airgel

Examples

Experimental program
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Effect test

example 1

[0033] (1) Dissolve 2.05g of 2,2'-dimethyl-4,4'-diaminobiphenyl (DMBZ) into 95mL of N-methylpyrrolidone (NMP) solvent, and stir at room temperature for 20min Finally, after it was completely dissolved, 2.95g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was added, and condensation polymerization was carried out at 25°C for 24 hours to obtain an anhydride group-terminated polyamic acid solution (diphenyl The molar ratio of anhydride monomer to diamine monomer is 1:0.7).

[0034] (2) Soak the chopped fibers in nitric acid for modification at 60°C. The modification time is 2 hours. After taking them out, wash them with ethanol and deionized water successively, and then dry them in a drying oven at a drying temperature of 40°C. Drying time is 6h.

[0035] (3) The polyamic acid solution obtained in step (1) is chemically imidized, and the catalyst pyridine 7mL and the dehydrating agent acetic anhydride 8mL (the molar ratio of pyridine and acetic anhydride to the dianhydr...

example 2

[0040](1) Dissolve 2.10g of 1,4-p-phenylenediamine into a solvent containing 95mL of N,N-dimethylformamide (DMF), stir at room temperature for 20min, then add 2.93g of 3 , 3',4,4'-benzophenonetetraacid dianhydride, carry out condensation polymerization at 25°C for 21h to obtain an anhydride group-terminated polyamic acid solution (the molar ratio of dianhydride monomer to diamine monomer is 1: 0.8).

[0041] (2) Soak chopped fibers in nitric acid for modification at 65°C. The modification time is 2.5 hours. After taking them out, wash them with ethanol and deionized water successively, and then dry them in a drying oven at a drying temperature of 45°C. , drying time is 7h.

[0042] (3) The polyamic acid solution obtained in step (1) is chemically imidized, and the catalyst pyridine 6.6mL and the dehydrating agent acetic anhydride 7.8mL (the molar ratio of pyridine and acetic anhydride to the dianhydride monomer is 8:8.1: 0.8) Add it into the polyamic acid solution, and stir ...

example 3

[0047] (1) Dissolve 2.15g of 4,4'-diaminodiphenyl ether into 95mL of dimethyl sulfoxide (DMSO) solvent, stir at room temperature for 20min, and then add 2.96g of benzene Tetraformic dianhydride was subjected to condensation polymerization reaction at 25° C. for 18 hours to obtain an anhydride group-terminated polyamic acid solution (the molar ratio of dianhydride monomer to diamine monomer was 1:0.9).

[0048] (2) Soak the chopped fibers in nitric acid at 70°C for modification, the modification time is 3 hours, after taking them out, wash them with ethanol and deionized water successively, and then dry them in a drying oven at a drying temperature of 50°C. Drying time is 8h.

[0049] (3) The polyamic acid solution obtained in step (1) is chemically imidized, and the catalyst pyridine 6.2mL and the dehydrating agent acetic anhydride 7.5mL (the molar ratio of pyridine and acetic anhydride to the dianhydride monomer is 8:8.2: 0.9) was added into the polyamic acid solution, and s...

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Abstract

The invention belongs to the field of preparation technology of nanoporous materials, and relates to a preparation method of chopped fiber layered reinforced polyimide airgel. The present invention uses modified chopped fibers as reinforcement materials, and the reinforced chopped fibers are evenly dispersed in the polyimide airgel structure in a layered manner, and the chopped fibers are interspersed in the polyimide airgel matrix as a skeleton , due to the small amount of fiber added and layered in the airgel matrix, the thermal bridge effect caused by fiber-to-fiber contact in heat conduction is avoided in the direction perpendicular to the fiber layer, so that the airgel material will not be reduced Its own thermal insulation performance and compressibility, and because the polyimide airgel matrix is ​​supported by crisscross crack-resistant chopped fibers, it greatly improves the crack resistance of the airgel composite material in the horizontal direction performance. The prepared fiber layered reinforced polyimide airgel has a density of 0.09-0.12g / cm 3 , The thermal conductivity at room temperature is 0.04793~0.04859W / (m·K).

Description

technical field [0001] The invention belongs to the field of preparation technology of nanoporous materials, and relates to a preparation method of chopped fiber layered reinforced polyimide airgel. Background technique [0002] Airgel is a kind of gel material whose dispersion medium is gas. The solid phase and pore structure are on the nanometer scale. It is currently the solid material with the smallest density and the smallest thermal conductivity in the world. Therefore, it has broad application prospects in aerospace lightweight high-temperature-resistant materials, fire-fighting clothing, and satellite surface protection materials. [0003] Polyimide (PI) airgel is a kind of organic polymer airgel containing imide ring in the main chain. Because the main chain contains a heterocyclic structure, it has excellent high and low temperature resistance, and also has Excellent mechanical properties, wear resistance and other excellent properties, so the mechanical propertie...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08J9/28C08L79/08C08L77/10C08L23/12C08K9/02C08K7/14D06M11/64D06M101/36D06M101/20
CPCC08J9/28D06M11/64C08J2379/08C08J2477/10C08J2423/12C08K9/02C08K7/14C08J2205/026D06M2101/36D06M2101/20
Inventor 崔升徐世玉付俊杰王子寒刘学宁袁美玉
Owner NANJING TECH UNIV
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