Synthesis and characterization of polyimide particles

Abstract

The PI particles were synthesis by colloid method, which use good solvent and poor solvent. The polyimide precursor was prepared from reaction between dianhydride, 4,4´- oxydianiline (ODA) in NMP (good solvent), which obtain Polyamic acid (PAA) precursor solution. The PAA was injected to poor solvent of hexane and suitable amount of surfactants to mix with rigorous agitation and/or sonication to break the droplet of PAA. Then, PAA colloids were obtained and the colloid was further changed to PI particle by the in-situ chemical imidization of PAA colloids in the solution. The PI particle was separated from solution by centrifuge and dried under vacuum. In this study, various types of poor solvents, various types of surfactant and reactor and propeller blade in the reaction were investigated to verify the suitable conditions for the reactions. The best condition that produced the smallest size particulate polyimide, that have the average diameters of 1 to 10 𝜇m, are by using hexane as poor solvent and use Acrydic A-1381 as surfactant with 6-FDA as the dianhydride. The reaction can be run at room temperature, insensitive to the time delay of imidization and improve by the reactor and the propeller blade. The temperature did not change particles site and thermal propertied of PI. The synthesized functionalized PI particle features at wave number near 1750, 1380 and 1370 cm⁻¹ were also observed in the FT-IR spectra correspond with imide characteristics. Their thermal properties are the degradation of polyimide particles which appeared above 450-600 ℃. These results indicated the success preparation method of polyimide particle materials that have potential applications for electrical appliances.