Method for converting macrocyclic polyimide oligomers to linear polyimides

摘要

Macrocyclic polyimide oligomers are prepared by the reaction of at least one diamine with at least one tetracarboxylic acid or dianhydride thereof in equimolar amounts, under conditions of high dilution of said reagents. The macrocyclic oligomers are capable of conversion into linear polyimides by heating with a primary amine in the presence of a macrocyclic polyimide polymerization catalyst, typically an alkaline earth or transition metal or salt thereof.