Soluble Phenyl- or Alkoxyphenyl-Substituted Rigid-Rod Polyamides and Polyimides Containing <i>m</i>-Terphenyls in the Main Chain

Abstract

4,4''-Diamino-5'-phenyl- or 4-alkoxyphenyl-m-terphenyl and 4,4''-dicarboxy-5'-phenyl-m-terphenyl were synthesized through pyrylium salts and used for the preparation of rigid-rod polyamides and polyimides. The polymers were characterized by inherent viscosity, elemental analysis, FT-IR, UV−vis, 1H NMR, 13C NMR, X-ray, DSC, TMA, TGA, isothermal gravimetric analysis, and moisture absorption. It was shown that the presence of the 4-alkoxyphenyl pendent groups enhanced remarkably the solubility of polymers as well as reduced the Tg's and thermal stability. In addition, the polyamide bearing 4-(dodecyloxy)phenyl side groups displayed softening.