How the monomer concentration of polymerization influences various properties of polybenzimidazole: A case study with poly(4,4′‐diphenylether‐5,5′‐bibenzimidazole)

摘要: In this work, a series of poly(4,4′-diphenylether-5,5′-bibenzimidazole)s (OPBIs) were synthesized from 4,4′-oxybis(benzoic acid) and 3,3′,4,4′-tetraaminobiphenyl through the variation initial monomer concentration with solution polycondensation technique in poly(phosphoric medium. The resulting polymers characterized by various techniques such as infrared (IR), nuclear magnetic resonance, dynamic mechanical analysis (DMA), thermogravimetric analysis. polymerization mixture played an important role controlling molecular weight polymers. A temperature-dependent IR study showed that free movement NH group imidazole ring was blocked absorbed moisture. DMA glass-transition temperature (Tg) varied weight, presence ether linkage OPBI polymer backbone had significant influence on Tg. high-molecular-weight tended to form supramolecular organization, which influenced thermal characteristic polymer. Photophysical studies demonstrated fluorescent characteristics both solid states. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009