AbstractA high‐pressure curing technique was developed to help determine the effects of solvent presence during the thermal curing of the polyimide poly (N,N'‐bis‐phenoxyphenylpyro‐mellitimide) (PMDA‐ODA). A powder form of this aromatic polyimide was produced from a polyamic acid solution using the high‐pressure thermal curing technique. Preliminary characterization of the powder indicates a high degree of crystallinity with a measured density of 1.46 ± 0.01 g/cm3 and a distinct melting point of 594°C. The addition of chemical curing agents to the polyamic acid solution prior to thermal treatment reduced the amount of crystallinity observed in the cured material. Molecular weight measurements of the polyamic acid precursor and powder suggest that the high degree of order observed in the powder is a result of degradation during cure. © 1994 John Wiley & Sons, Inc.This article is a US Government work and, as such, is in the public domain in the United States of America