Patent ID: 10414868

Abstract:
The present invention provides a preparation method of polyimide, comprising the following steps: a) carrying out a dehydration polymerization reaction on a diamine and an anhydride of an organic acid in a non-polar solvent to obtain a mixture, the non-polar solvent being one or more of arene, aliphatic hydrocarbon, halogenated arene and halogenated aliphatic hydrocarbon, and the anhydride of the organic acid being one or more of dianhydride and single anhydride: and b) filtering the mixture obtained in step a) and drying to obtain the polyimide. In the present invention, the dehydration polymerization reaction between the diamine and the anhydride of the organic acid can be carried out directly in the non-polar solvent to obtain the polyimide which cannot be dissolved in the non-polar solvent. Therefore, polyimide powder with fine particles can be obtained by directly filtering and drying the reaction mixture without washing. Not only complex washing and grinding processes are not needed, but also the production period is shortened, the production cost is reduced, and the large-scale production becomes more convenient.