Highly crystalline polyimide particles

Abstract

Several kinds of highly crystalline polyimide particles were obtained by heating polyamic acid solutions at 180°C that induced the thermal imidization of polyamic acids in N-methyl-2-pyrrolidone (NMP). The morphology of the particles was a sheaf or coral type that was similar to a polymer spherulite. The WAXD analysis revealed that the particles were highly crystalline. The size of the particles was in the range from 1μm to 10 μm. It was concluded from the electron diffraction studies that the molecular axis of polyimide in the (PMDA/PPD) particle lay perpendicular to the sheaf surface.