Morphology and Structure of Crystallite Polyimide Particles Prepared by the Thermal Imidization in Polymer Solution

Abstract

Several kinds of highly crystalline polyimide particles were obtained by heating polyamic acid solutions at 180°C as the result of thermal imidization of polyamic acids in N-methyl-2-pyrrolidone (NMP). The morphology of the particles was a sheaf or coral that was similar to a spherulite of the polymer, and they were found to be highly crystalline particles from the analysis of WAXS. The size of the particles was in the range from 1 μm to 10 μm. The electron diffraction patterns from the crystal plane of (110) and (200) indicated that the molecular axis of the polyimide lies perpendicular to the surface of the sheaf for the PMDA/PPD particle.