Synthesis and properties of polybenzazoles containing flexible methylene in backbone

Abstract

A novel series of polybenzazoles with rigid-rod benzoxazole cycle and soft methylene segment was designed and synthesized via solution condensation polymerizations from 4,6-diamino-1,3-benzenediol diphosphate, terephthalic acid and aliphatic dicarboxylic acid. The structures of polybenzazoles were characterized by means of FT-IR, 1 H NMR and Wide-angle X-ray diffraction (WAXRD). All the polymers show excellent thermal stability and the T d s was above 471uC. The intrinsic viscosities [g] of the polymers ranged from 0.8 to 0.9. The UV-Vis absorption peaks of the polymers in MSA were blue-shifted from 429 nm for PBO to 291 nm for PBOC7, and the Stokes shifts in PL spectra enlarged.