Aromatic diamine and polyimide containing tolyl and non-coplanar structure and their preparation methods

A non-coplanar, aromatic diamine technology, applied in the field of polyimide, can solve the problems of restricting the industrial production of diamine monomers containing large side groups, few types of diamine monomers containing large side groups, and complicated purification methods. , to achieve the effect of favorable diffusion and dissolution, excellent solubility, and easy safe operation

Inactive Publication Date: 2018-09-14
WUHAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The above-mentioned large side group-containing diamine monomers have few types, and the synthesis route is complicated, and the side reactions are

Method used

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  • Aromatic diamine and polyimide containing tolyl and non-coplanar structure and their preparation methods
  • Aromatic diamine and polyimide containing tolyl and non-coplanar structure and their preparation methods
  • Aromatic diamine and polyimide containing tolyl and non-coplanar structure and their preparation methods

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0057] Preparation of diamine monomer:

[0058] (1) Add the mixture of 24.24g (0.2mol) 2,6-dimethylaniline and 150mL distilled water into a 250mL three-neck round-bottomed flask equipped with magnetic stirring, reflux condenser, constant pressure dropping funnel, nitrogen inlet and outlet, and stir at room temperature for 0.5h ;

[0059] (2) Pass in the inert gas nitrogen, then add dropwise a mixture of 20mL concentrated hydrochloric acid (12mol / L) and 20mL distilled water, drop it within 1h; then raise the temperature to 110°C, add dropwise 12.36g (0.101mol) 4-methylbenzene Formaldehyde, drop it within 1h; maintain the temperature of 110°C for 12h, cool to room temperature; pour the product into excess methanol, add 200mL sodium hydroxide (15wt%) to form a white precipitate, filter and dry, wash with distilled water several times, and use the crude product Recrystallization of n-butanol yielded polymer grade aromatic diamine monomer (yield 90%, purity 95%). The H NMR and C ...

Embodiment 2

[0066] Preparation of diamine monomer:

[0067] (1) Add 24.24g (0.2mol) of 2,6-dimethylaniline and 120mL of distilled water into a 250mL three-neck round bottom flask equipped with magnetic stirring, reflux condenser, constant pressure dropping funnel, nitrogen inlet and outlet, and stir for 2 hours at room temperature;

[0068] (2) Pass in the inert gas nitrogen, then add dropwise a mixture of 20mL concentrated hydrochloric acid (12mol / L) and 20mL distilled water, drop it within 1h; then raise the temperature to 90°C, add dropwise 12.85g (0.105mol) 4-methylbenzene Formaldehyde, drop it within 1h; maintain the temperature at 90°C for 8h, cool to room temperature; pour the product into excess methanol, add 200mL sodium hydroxide (15wt%) to form a white precipitate, filter and dry, wash with distilled water several times, and use the crude product Recrystallization of n-butanol yielded polymer grade aromatic diamine monomer (yield 80%, purity 90%).

[0069] Synthesis of polyimi...

Embodiment 3

[0073] Preparation of diamine monomer:

[0074] (1) Add 24.24g (0.2mol) of 2,6-dimethylaniline and 100mL of distilled water into a 250mL three-neck round bottom flask equipped with magnetic stirring, reflux condenser, constant pressure dropping funnel, nitrogen inlet and outlet, and stir for 1 hour at room temperature;

[0075] (2) Pass in the inert gas nitrogen, then add dropwise a mixture of 20mL concentrated hydrochloric acid (12mol / L) and 20mL distilled water, drop it within 1h; then raise the temperature to 80°C, add dropwise 13.46g (0.11mol) 4-methylbenzene Formaldehyde, drop it within 1h; maintain the temperature of 80°C for 12h, cool to room temperature; pour the product into excess methanol, add 200mL sodium hydroxide (15wt%) to form a white precipitate, filter and dry, wash with distilled water several times, and use the crude product Recrystallization of n-butanol yielded polymer grade aromatic diamine monomer (yield 50%, purity 92%).

[0076] Synthesis of polyimid...

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Abstract

The invention discloses aromatic diamine and polyimide containing tolyl and non-coplanar structure and their preparation methods. A general formula of the aromatic diamine is shown in the description.The preparation method of the aromatic diamine includes: allowing 2,6-dimethylaniline and p-tolualdehyde to react at the temperature of 80-110 DEG C under the protection of excessive hydrochloric acid in the nitrogen atmosphere, with water serving as a solvent, to obtain crude aromatic diamine; performing normal butanol recrystallization to obtain polymeric aromatic diamine, up to 90% in yield; subjecting the polymeric aromatic diamine and different dianhydrides to one-step high temperature polycondensation to obtain polyimide. The glass transition temperature herein is up to 376 DEG C; 5% thermogravimetric decomposition temperature is up to 517 DEG C, with very high thermal stability shown; diamine monomer substitutive methyl group is a nonpolar group and is of symmetric substitution such that the synthesized nonpolar polymeric polyimide has dielectric constant down to 2.47 under 1 KHz, with excellent solubility; the forming technique temperature of polyimide is lowered.

Description

technical field [0001] The invention relates to the technical field of polyimide, in particular to an aromatic diamine containing toluene and a non-coplanar structure, polyimide and a preparation method thereof. Background technique [0002] As a high-performance polymer material, polyimide is widely used in high-tech fields such as aerospace, automotive and microelectronics industries due to its excellent thermal stability, excellent mechanical properties, low dielectric constant and low thermal expansion coefficient. However, traditional commercial aromatic polyimides usually exhibit poor solubility and high melting temperature, for example, dianhydride monomers are pyromellitic dianhydride (PMDA), 3,3′,4,4′-linked Pyrellitic dianhydride (BPDA) polyimide is usually only soluble in several strong protic acids such as concentrated sulfuric acid and concentrated hydrochloric acid. At present, the industrialized polyimide preparation method is mainly a two-step method. Firstl...

Claims

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Application Information

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IPC IPC(8): C07C211/50C07C209/78C08G73/10
CPCC07C209/78C07C211/50C08G73/1007C08G73/1057C08G73/1064C08G73/1067C08G73/1071
Inventor 徐任信李铮
Owner WUHAN UNIV OF TECH
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