Preparation method of low-density polyimide soft foam

Abstract

The invention provides a preparation method of low-density polyimide soft foam, comprising the following steps of: (A) preparing A powder: mixing binary anhydride D1, de-ionized water and C1-C2 alkyl monohydric alcohol to react to be transparent at a temperature of 60-90 DEG C; reducing the temperature to 25-55 DEG C and adding diamine or diisocyanate DA1 which has the equal mol amount of the binary anhydride; reacting at the state that the temperature is less than or equal to 40 DEG C for 30-120 min and cooling to a room temperature; continually agitating for 120 min to obtain a liquid resinprecursor polyamide-ester with the solid content of 55-65% and viscosity of less than 10000 cp; drying in vacuum and crushing to obtain the A powder; (2) preparing B powder: mixing binary anhydride D2 with diamine DA2 to synthesize polyamic acid resin with the viscosity of 800-1500 p and the solid content of 15-40%; drying, carrying out ring closing, and ageing to obtain the B powder with Tg morethan 300 DEG C; (3) foaming, fully mixing the A powder and the B powder, foaming, carrying out ring closing and aging to obtain the multipurpose polyimide soft foam, wherein the mass percentage of the B powder in the A powder and the B powder is x and x is more than 0 and less than or equal to 40%.

Description

technical field

[0001] The invention relates to a preparation method of low-density polyimide soft foam. Background technique

[0002] After nearly 50 years of rapid development at home and abroad, the demand for high-performance polyimide foam is increasing, and the domestic demand for polyimide foam is also growing rapidly. The biggest task at present is to further achieve high performance and low cost.

[0003] There are many kinds of thermosetting and thermoplastic polyimides. According to incomplete statistics, there are 200 to 300 kinds of dianhydride and diamine monomers that can be used to synthesize polyimides. There are many methods for synthesizing polyimides, which can be used according to different applications. The purpose is to choose different monomers and different synthesis methods, so there are thousands of polyimide materials that have been synthesized or studied. The diversity of synthesis methods of this material is not available in other polymer mate...

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