Method for preparing polyimide

A technology of polyimide and polyamic acid, which is applied in the field of preparing polyimide, can solve problems such as yellowing, and achieve the effects of avoiding yellowing, high transparency, high thermal stability and mechanical properties

Active Publication Date: 2016-11-09
JIANGHAN UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] In order to solve the problem in the prior art that the active end-capping agent makes the polyimide film form yellow or dark brown at high temperature, the embodiment of the present invention provides a method for preparing polyimide

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  • Method for preparing polyimide

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Embodiment 1

[0039] The embodiment of the present invention provides a method for preparing polyimide, the method comprising: under the protection of argon, 2.9558g (0.00923mol) 2,2'-bis Add (trifluoromethyl)diaminobiphenyl and 0.2451g (0.00092mol) 1,1'-bis(4-aminophenyl)cyclohexane mixed diamine (molar ratio 10:1) to 14.88g polar solvent N,N-Dimethylacetamide, stir to dissolve the diamine completely, then add 3.1021g (0.01mol) 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride to the reaction system, and react for 4h Afterwards, 0.149g (0.0006mol) of end-capping agent 4-phenylacetylene phthalic anhydride was added, and the reaction was continued for 24h to obtain a polyamic acid solution.

[0040] Wherein, the structure of 4-phenylacetylene phthalic anhydride is:.

[0041] The mixture of 0.51g triethylamine and 1.61g pyridine is used as a catalyst, the catalyst is added to the polyamic acid solution, and 9.33g dehydrating agent acetic anhydride is added, and the reaction is continued f...

Embodiment 2

[0049] The embodiment of the present invention provides a method for preparing polyimide, the method comprising: under nitrogen protection, 1.6012g (0.005mol) 2,2'-bis( Trifluoromethyl) diaminobiphenyl and 1.6222g (0.006mol) 1,1'-bis(4-aminophenyl)-4-tert-butylcyclohexane mixed diamine (molar ratio 1:1.2) was added to 14.94g Polar solvent N,N-dimethylacetamide, stir to dissolve the diamine completely, then add 3.1021g (0.01mol) 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride to the reaction system After 4 hours of reaction, 0.0984 g (0.0006 mol) of norbornene anhydride was added, and the reaction was continued for 24 hours to obtain a polyamic acid solution.

[0050] Wherein, the structure of norbornene anhydride is:.

[0051] The mixture of 0.29g triethylamine and 1.78g pyridine is used as a catalyst, the catalyst is added to the polyamic acid solution, and 9.33g dehydrating agent acetic anhydride is added, and the reaction is continued for 24 hours to obtain a polyimid...

Embodiment 3

[0055] The embodiment of the present invention provides a method for preparing polyimide, the method comprising: under argon protection, 2.6868g (0.00839mol) 2,2'-bis Add (trifluoromethyl)diaminobiphenyl and 0.4449g (0.00167mol) 1,1'-bis(4-aminophenyl)cyclohexane mixed diamine (molar ratio 5:1) to 15.97g polar solvent After N-methylpyrrolidone was stirred to completely dissolve the diamine, 2.2212g (0.005mol) of 4,4'-hexafluoroisopropylphthalic anhydride, 1.4711g (0.005mol) of 3, 3',4,4'-Biphenyltetracarboxylic dianhydride mixed dianhydride, reacted for 4 hours, added 0.0208g (0.00012mol) of 4-cyanophthalic anhydride, and continued to react for 24 hours to obtain a polyamic acid solution.

[0056] Among them, the structure of 4-cyanophthalic anhydride is.

[0057] The mixture of 2.26g triethylamine and 0.22g pyridine is used as a catalyst, the catalyst is added to the polyamic acid solution, and 9.24g dehydrating agent acetic anhydride is added, and the reaction is continued ...

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Abstract

The invention discloses a method for preparing polyimide and belongs to the field of polymer materials. The method includes the steps that in a first polar solvent, diamine, dianhydride and an end-capping reagent react to obtain a polyamide acid solution, wherein the end-capping reagent is monoanhydride containing active functional groups which can have radical polymerization; the polyamide acid solution is imidized and extracted to obtain polyimide prepolymer; the polyimide prepolymer is dissolved in a second polar solvent, a radical initiator is added, a mixed glue solution is obtained, the mixed glue solution is solidified, cooled to room temperature and stripped, and membrane-shaped polyimide is obtained. The active groups of the end-capping reagent are cross-linked at low temperature, so a polyimide membrane keeps high transparency, and application range of the polyimide membrane in the field of flexible display materials is widened.

Description

technical field [0001] The invention relates to the field of polymer materials, in particular to a method for preparing polyimide. Background technique [0002] Due to its rigid molecular chain structure and strong interaction between chains, traditional polyimide is usually difficult to dissolve in common organic solvents, making polyimide difficult to process and shape. In addition, most traditional polyimide films exhibit light yellow or dark brown due to the effect of intermolecular and intramolecular charge-transfer complexes (CTCs), which limits their applications in liquid crystal displays and other fields. . In order to improve the solubility and transparency of traditional polyimides, bulky substituents, flexible groups, asymmetric structures, alicyclic structures, and non-coplanar structures are usually introduced into the molecular chain. The introduction of the above-mentioned groups can improve the solubility and transparency of traditional polyimides, but to ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G73/12C08G73/10C08F299/02C08J5/18C08J3/24
Inventor 刘继延尤庆亮张玲付华刘学清于洁陈妤红阮敏
Owner JIANGHAN UNIVERSITY
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