Preparation of acetylene-substituted polyimide oligomers and polyimide polymers

摘要

An improved method is described for the preparation of certain acetylene-substituted polyimide oligomers which are substantially free of reaction solvent and thus do not fracture at use temperatures above 600 DEG F. (316 DEG C.). The acetylene-substituted polyimide oligomers are prepared by reacting an aromatic tetracarboxylic acid dianhydride such as benzophenone tetracarboxylic acid dianhydride with an aromatic diamino compound such as a diamino polyarylene ether in the presence of N-methyl-2-pyrrolidone (NMP) as a solvent to form a first reaction product which is in turn reacted with an aminoarylacetylene to form a solution of an acetylene-substituted polyamic acid oligomer in NMP. The polyamic acid oligomer is thereafter converted to the desired acetylene-terminated polyimide oligomer by heating in the continued presence of said N-methyl-2-pyrrolidone. The N-methyl-2-pyrrolidone can then be removed by any suitable means such as by precipitation of the acetylene-substituted polyimide oligomer in a non-solvent such as ethanol.