Synthesis and characterization of soluble, blue-fluorescent polyamides and polyimides containing substituted p-terphenyl as well as long aliphatic segments in the main chain

Abstract

A novel class of semiflexible polyamides and polyimides bearing substituted p-terphenyl as well as long aliphatic segments in the main chain were synthesized through pyrylium salts. Characterization of polymers was accomplished by inherent viscosity, elemental analysis, FT-IR, NMR, UV-vis luminescence spectroscopy, X-ray analysis, differential scanning calorimetry, thermomechanical analysis, thermogravimetric analysis, isothermal gravimetric analysis, and water uptake measurements. Polyamides displayed a degree of crystallinity and dissolved in polar aprotic solvents containing lithium chloride, as well as in trichloroacetic acid. Polyimides were amorphous and showed an excellent solubility, being soluble in various common solvents. The solutions of polyamides in DMF were blue-fluorescent with maxima at 362–370 nm. The emission maxima were not influenced appreciably upon the structure of the pendent groups and the length of the aliphatic spacers of backbone. The polymers possessed Tgs at 98–131°C and exhibited a satisfactory thermal stability. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3646–3656, 1999