A kind of high strength and high heat resistance polyimide microporous film and preparation method thereof

Abstract

The invention provides a high-strength high-heat-resistance polyimide microporous thin film and a preparation method thereof. The preparation method includes: enabling dianhydride and two kinds of diamine to be in copolymerization in an organic solvent; adding a certain amount of a hole forming agent in the reaction process to finally obtain a polyamide acid resin solution; coating the resin solution for film forming; performing thermal treatment and thermal imidization treatment to obtain the polyimide microporous thin film, wherein content of aromatic heterocycte diamine 2-(4-amino phenyl)-5-aminobenzooxazole or 2-(4-amino phenyl)-5-aminobenzoimidazole accounts for 20-60% of total molar weight of diamine. The polyimide thin obtained by the method is high in glass transition temperature, good in heat resistance and excellent in mechanical performance. Experimental results show that the polyimide microporous thin film prepared by the method is smooth in surface and uniform in pore distribution, pore size range is 5-30 um, tensile strength is 20-80 MPa, glass transition temperature is greater than 30 DEG C, and thermal weight loss temperature is 510-550 DEG C.

Description

technical field [0001] The invention relates to a high-strength and high-heat-resistant polyimide microporous film and a preparation method thereof, belonging to the field of polymer material preparation. Background technique [0002] Porous polymer materials are an important branch in the field of polymer materials. Porous polyimide materials have excellent properties such as heat resistance, heat insulation, noise reduction, impact resistance, dimensional stability, wave transparency and flame retardancy. They can be used as media Electricity, wave absorption, sound insulation and heat insulation and flame retardant materials have a wide range of applications. Especially in cutting-edge technology fields such as aerospace aircraft, surface ships, submarines, rail transit and microelectronics. In some special application fields, it is required to have more excellent mechanical properties, high temperature resistance, radiation resistance, heat and humidity resistance and c...

AI Technical Summary

Problems solved by technology

However, the dianhydrides and diamines used in these methods are all conventional monomers, and the glass transition temperature of the prepared microporous film is about 250°C, and the long-term use and high temperature resistance are about 200°C. Inhomogeneous cell structure and poor mechanical properties

[0006] In short, the above methods obtained are all conventional polyimide microporous film materials, which have poor resistance to high temperatures above 300°C and have defects such as poor mechanical properties.

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