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A method of recycling polyimide waste

A polyimide and waste technology, applied in the field of recycling polyimide waste, can solve the problems of high hydrolysis requirement of polyimide waste, low monomer yield and purity, etc., and achieve high yield , strong reactivity, high purity effect

Active Publication Date: 2020-10-02
宏威高新材料有限公司 +2
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0011] One of the objectives of the present invention is to propose a method for recycling polyimide waste, which solves the problem of using strong alkali solutions such as sodium hydroxide or potassium hydroxide to hydrolyze polyimide waste in the prior art. The technical problems of low efficiency and purity, and the need for high pressure to hydrolyze polyimide waste with ammonia water

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  • A method of recycling polyimide waste
  • A method of recycling polyimide waste
  • A method of recycling polyimide waste

Examples

Experimental program
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Effect test

Embodiment 1

[0057] In a 2L three-necked reaction flask equipped with a spherical reflux condenser and a mechanical stirrer, 100 g of polyimide film fragments (PMDA and ODA) with a pyromellitic dianhydride / 4,4'-diaminodiphenyl ether structure were added. The number of moles is 0.2615mol), after nitrogen replacement, add 80% hydrazine hydrate 150g (3.138mol), PMDA: hydrazine hydrate=1: 12, then be warming up to 85 ℃ and maintain under the condition of nitrogen blanketing, observe reaction phenomenon , when the film fragments disappear and a large amount of white powder is precipitated, take samples and conduct liquid chromatography analysis on the white solid and liquid respectively, and confirm that the hydrazinolysis reaction is completed and the temperature is lowered to below 40°C, and 4,4'-diaminodiphenyl ether is filtered out The crude product was then washed with pure water for 4 times, dried in vacuum and then sublimated with a vacuum sublimator to obtain 51.32 g of 4,4'-diaminodiphe...

Embodiment 2

[0060] Add 100g of polyimide with the structure of 4,4'-diphenyl ether tetra-acid dianhydride / 4,4'-diaminodiphenyl ether into a 2L three-necked reaction flask equipped with a spherical reflux condenser and a mechanical stirrer Powder (the number of moles of ODPA and ODA is 0.2108mol), after nitrogen replacement, add 65% hydrazine hydrate 150g (2.55mol), ODPA: hydrazine hydrate=1: 12, then be warming up to 85 ℃ under the condition of nitrogen blanketing and Maintain and observe the reaction phenomenon. When the film fragments disappear and a large amount of white powder precipitates, take samples and conduct liquid chromatography analysis on the white solid and liquid respectively. After the hydrazinolysis reaction is completed, the temperature is lowered to below 40°C, and 4,4'- The crude diaminodiphenyl ether was washed four times with pure water, dried in vacuum and then sublimated with a vacuum sublimator to obtain 41.79 g of 4,4'-diaminodiphenyl ether with a purity of 99.6%...

Embodiment 3

[0063] Add 100g of polyimide with 4,4'-benzophenonetetraacid dianhydride / 4,4'-diaminodiphenylmethane structure in a 2L three-necked reaction flask equipped with a spherical reflux condenser and a mechanical stirrer Powder (the molar number of BTDA and MDA is 0.2063mol), after nitrogen displacement, add 70% hydrazine hydrate 150g (2.785mol), BTDA: hydrazine hydrate=1: 13.5, be warming up to 100 ℃ under the condition of nitrogen blanketing then and Maintain and observe the reaction phenomenon. When the film fragments disappear and a large amount of white powder precipitates, take samples and conduct liquid chromatography analysis on the white solid and liquid respectively. After the hydrazinolysis reaction is completed, the temperature is lowered to below 40°C, and 4,4'- The crude diaminodiphenylmethane was washed four times with pure water, dried in vacuum and then sublimated with a vacuum sublimator to obtain 40.08 g of 4,4'-diaminodiphenylmethane with a purity of 99.4% and a y...

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Abstract

The invention discloses a method for recovering polyimide wastes, particularly relates to the technical field of polyimide waste recovery, and solves the technical problems in the prior art that the yield and the purity of a monomer obtained by using strong alkaline solutions of sodium hydroxide or potassium hydroxide and the like to hydrolyze the polyimide wastes is not high and a relatively highpressure is needed when ammonium hydroxide is used for hydrolyzing the polyimide wastes. The method comprises the following steps of: using hydrazine hydrate to enable the polyimide wastes to generate a hydrazinolysis reaction under normal pressure to obtain reaction liquid; after the hydrazinolysis reaction is finished, filtering the reaction liquid; respectively processing the filtered solid and filtrate so as to obtain an aromatic diamine monomer and an aromatic dianhydride monomer. According to the method disclosed by the invention, the complete hydrazinolysis of polyimide can be realizedunder the normal pressure, and the problem that the ammonium hydroxide needs to be pressurized is overcome. No metal ions are introduced in the whole recovery process, ether bond breakage is almost avoided, and the method is a relatively feasible method for recovering the aromatic dianhydride and aromatic diamine monomers by the polyimide.

Description

technical field [0001] The invention relates to the technical field of recycling polyimide waste, in particular to a method for recycling polyimide waste. Background technique [0002] Because polyimide has high thermal stability and excellent mechanical properties, electrical insulation properties, radiation resistance and dimensional stability, etc., it has been widely used in the production of insulating materials and engineering plastics. During the application of polyimide, a large amount of waste will inevitably be generated. How to recycle polyimide waste has become a research direction of polyimide. [0003] Polyimide is a large class of special polymer materials composed of aromatic dianhydride and aromatic diamine. It has good comprehensive performance and high price. Because the preparation cost of most aromatic dianhydrides and aromatic diamines is high, and polyimide has the characteristics of hydrolysis reaction with alkali, it is commercially desirable to pre...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D493/04C07C217/90C07C213/02C07C213/10C07C211/50C07C209/62C07C209/84
CPCC07C209/62C07C209/84C07C213/02C07C213/10C07D493/04C07C217/90C07C211/50
Inventor 不公告发明人
Owner 宏威高新材料有限公司
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