SYNTHESIS AND PROPERTIES OF POLY[ARYLENE ETHER (N-ARYLENEBENZIMIDAZOLE)]S

Poly (arylene ether) s containing N-arylenebenzimidazole groups were p repared by the aromatic nucleophilic displacement reaction of two new bis(hydroxyphenyl-N-arylenebenzimidazole)s with activated aromatic dif luorides in sulfolane at 200-degrees-C in the presence of anhydrous po tassium carbonate. The bis (hydroxyphenyl-N-arylenebenzimidazole)s wer e prepared from bis (o-aminoanilino)arylenes and phenyl-4-hydroxybenzo ate. The polymers were soluble in N-methyl-2-pyrrolidinone and m-creso l and exhibited inherent viscosities from 0.37-0.86 dL/g and glass tra nsition temperatures from 219-289-degrees-C. Thermogravimetric analyse s showed 5% weight losses from 463-506-degrees-C in air and 467-522-de grees-C in nitrogen. Unoriented thin films exhibited tensile strengths , moduli, and break elongations at 23-degrees-C of 10.2-12.5 ksi, 318- 365 ksi, and 4-7%, respectively, and at 177-degrees-C of 5.1-6.9 ksi, 256-296 ksi, and 1-5%, respectively. A 50: 50 random copolymer prepare d from 1,3-bis(4-fluorobenzoyl)benzene, iphenylene)-bis[2-(4-hydroxyph enyl)benzimidazole], and 5,5'-bis[2-(4-hydroxyphenyl)benzimidazole] ex hibited higher moisture absorption and lower tensile properties than t hose predicted by a rule of mixtures relationship. The chemical, physi cal, and mechanical properties of these polymers are discussed. (C) 19 93 John Wiley & Sons, Inc.