Heat‐resistant polymers containing bipyridyl units. III. Polyimides having <i>o</i>‐, <i>m</i>‐, or <i>p</i>‐phenylenedioxy linkage

Abstract

Abstract New series of diamines having pyridine rings and o ‐, m ‐, or p ‐phenylenedioxy linkages were prepared by condensation of chloronitropyridine with isomeric dihydroxybenzenes followed by chemical reduction. The polymerization of the diamines with benzo‐phenonetetracarboxylic acid dianhydride gave polyamic acids with the inherent viscosities in the range 0.21 to 1.30 dl/g. The conversion of these polyamic acids to polyimides was carried out thermally and the resulting polyimides exhibited very good solubility in organic solvents.