A kind of preparation method of rigid closed-cell polyimide foam

Abstract

The invention relates to a preparation method of hard closed-cell polyimide foam and belongs to the field of a preparation technology of a polymer polyimide foam material. The preparation method of the invention comprises the following steps: adding aromatic dianhydride into a polar solvent, and esterfying by adding an excessive amount of micromolecular fatty alcohol to obtain a solution A; addingdiamine, a foam stabilizer and an end-capping reagent into the solution A, reacting for 0.5-3 h to obtain a solution B, drying the solution B to remove the polar solvent, and crushing to obtain a precursor powder; placing the precursor powder into an open vessel and putting the open vessel with the precursor powder into a pressure vessel, vacuum-pumping to remove air and introducing CO2, heating,pressurizing, and finally cooling naturally and releasing pressure to obtain crosslinked polyimide foam. According to the method, nontoxic, odorless, non-combustible and cheap CO2 which is easily available is used as foaming gas. The preparation method is novel and has a wide application system.

Description

technical field

[0001] The invention relates to a preparation method of rigid closed-cell polyimide foam, which belongs to the technical field of preparation of polymer polyimide foam materials. Background technique

[0002] Polyimide foam has excellent flame retardancy, high temperature resistance, and open flame resistance, and is a type of high-performance foam material. Compared with other types of foamed plastics, it does not produce harmful gases during use, has a low density, a wide range of performance adjustments, and is easy to install and disassemble. It has been widely used abroad as a heat insulation and noise reduction material.

[0003] The patent US3249561 of DuPont Company of the United States first disclosed a preparation method of polyimide foam. In this patent, a dehydrating agent is added to the polyamic acid solution, and then an acid that can generate gas is added. After foaming and solidification, polyimide foam is obtained. , however, the cell size ...