Process for molding acetylene end-capped polyimide oligomers

In a process for preparing a thermoset molding of an acetylene end-capped polyimide oligomer;

• the improvement which consists essentially of:
• a. Filling a mold with acetylene end-capped polyimide oligomer particles of a size such that at least 50 weight % of said particles will pass through a 28-mesh screen (U.S. Standard),
• b. Subjecting the particles to a pressure of at least about 50,000 psi at ambient temperature to prepare a preformed molding having a density of at least about 1.23 gms/ml, and
• c. Removing the preformed molding from the mold and heating it to a temperature below the melting point of said oligomer for a period of time sufficient to cross link the molding;
• where the acetylene end-capped polyimide oligomer has the structure:
• ##STR5## where n has an average value of from 1 to about 10, where each of R and R' is independently selected from the group consisting of a phenylene group, a naphthalene group, or ##STR6## where X is ##STR7## --CF.sub.2 --, or a bond, and where R" has the structure:
• ##STR8## and where X is as defined above.