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Preparation method for synthesizing soluble polyimide in polyphosphoric acids

A technology of soluble polyimide and polyphosphoric acid, applied in the field of preparation of aromatic polyimide, to achieve high molecular weight, good heat resistance, and expand the application range

Inactive Publication Date: 2009-02-18
DONGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] The technical problem to be solved by the present invention is to provide a preparation method for synthesizing soluble polyimide in polyphosphoric acid. The polyimide of the present invention has higher molecular weight and good heat resistance, and effectively solves the problem of The problem of the solubility of traditional polyimide materials is solved, and the application range of polyimide is expanded. The preparation process of the invention is simple, the cost is low, and the environmental pollution is small

Method used

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  • Preparation method for synthesizing soluble polyimide in polyphosphoric acids

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] (1) Add P to a 100ml round bottom three-neck flask 2 o 5 40ml of polyphosphoric acid with a content of 80% was passed through nitrogen for deoxidation protection, 2.92g (0.012mol) of diaminodiphenylethane BAPE was added, the temperature was raised to 100°C, and the concentration was 0.3mol / L after rapid mechanical stirring until it was completely dissolved. solution, cooled to room temperature; add 3,3',4,4'-benzophenone tetracarboxylic dianhydride BTDA3.86g (0.012mol), react at a temperature of 180°C for 4hours, then raise the temperature to 220°C to continue the reaction 4hours, carry out sufficient thermal imidization, and obtain a brown-yellow polyimide solution.

[0023] (2) Soak the polyimide slurry prepared above in deionized water at 60° C. for 48 hours, and then wash with deionized water at 60° C. several times to fully remove the reaction medium polyphosphoric acid PPA. After vacuum filtration, the product was dried in a vacuum oven at 80° C. to obtain 6.23 ...

Embodiment 2

[0026] (1) Add 40ml of polyphosphoric acid to a 100ml round-bottomed three-necked flask, and 21g of P 2 o 5 Mix it with the above polyphosphoric acid PPA under the protection of nitrogen, and fully stir it at 120°C for 2 hours to obtain a clear PPA 2 o 5 Content is the polyphosphoric acid PPA solution of 84%, is cooled to 40-60 ℃, for subsequent use.

[0027] (2) Add 40ml of the 84% polyphosphoric acid prepared above in a new 100ml round-bottomed three-neck flask, pass nitrogen gas for deoxidation protection, add 2.92g (0.012mol) of diaminodiphenylethane BAPE, and heat up to 100 ℃, rapid mechanical stirring until completely dissolved to form a solution with a concentration of 0.3mol / L, and cooled to room temperature; then add 3.86g (0.012mol) of 3,3',4,4'-benzophenonetetracarboxylic dianhydride BTDA, React at a temperature of 180° C. for 4 hours, then raise the temperature to 220° C. and continue the reaction for 4 hours to perform sufficient thermal imidization to obtain a...

Embodiment 3

[0030] The difference between this embodiment and Example 2 is: in step (1), add 36g of P 2 o 5 , can get P 2 o 5 Content is the polyphosphoric acid PPA solution of 86%, and other implementation steps are identical with embodiment 2.

[0031] In this embodiment, 5.85 g of tan polyimide solid powder was obtained, and the yield was 86.3%. The intrinsic viscosity measured by Ubbelohde viscometer at 25°C is 0.568dL·g -1 (Concentrated sulfuric acid is the solvent).

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Abstract

The invention relates to a method for preparing soluble polyimide synthesized in polyphosphoric acid, including the following steps: (1) P2O5 powder is mixed with polyphosphoric acid (PPA) under nitrogen protection, stirred sufficiently under 100-150 DEG C to achieve polyphosphoric acid (PPA) solution with different P2O5 contents, and cooled to 40-60 DEG C for standby use; (2) dianhydride monomer and diamine monomer (mole ratio: 1:0.8-1:1.4) are added into the prepared polyphosphoric acid; the mass fraction of the reaction monomer is 5-40 percent of polyphosphoric acid solution, a polycondensation is conducted under inert gas protection, thermal imidization is conducted sufficiently, and then the material is washed by deionized water to achieve polyimide resin powder. The polyimide prepared by the method can effectively solve the problem of the poor solubility of the traditional polyimide materials, and the preparation process is simple, the cost is low and the environmental pollution is small.

Description

technical field [0001] The invention belongs to the field of preparation of aromatic polyimides, in particular to a preparation method for synthesizing soluble polyimides in polyphosphoric acid. Background technique [0002] Since polyimide was first synthesized in 1908, polyimide has excellent electrical and mechanical properties, high thermal stability, thermal oxidation and chemical stability, small thermal expansion coefficient, and good solvent resistance. , Dimensional stability and processing fluidity, easy to form complex shapes and high-precision parts, and many other excellent properties, are widely used in high-tech fields such as aerospace, electrical appliances, machinery, chemicals, and microelectronics. [0003] The conjugated system, ladder and semi-ladder chain structure formed by the aromatic heterocyclic structure in the polyimide molecule makes the molecular chain have strong rigidity, and the energy barrier for the free rotation of the molecular segment ...

Claims

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Application Information

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IPC IPC(8): C08G73/10
Inventor 张清华金亮左铖陈大俊
Owner DONGHUA UNIV