Synthesis and properties of poly[arylene ether (N‐arylenebenzimidazole)

Abstract

AbstractPoly(arylene ether)s containing N‐arylenebenzimidazole groups were prepared by the aromatic nucleophilic displacement reaction of two new bis(hydroxyphenyl‐N‐arylenebenzimidazole)s with activated aromatic difluorides in sulfolane at 200°C in the presence of anhydrous potassium carbonate. The bis(hydroxyphenyl‐N‐arylenebenzimidazole)s were prepared from bis(o‐aminoanilino) arylenes and phenyl‐4‐hydroxybenzoate. The polymers were soluble in N‐methyl‐2‐pyrrolidinone and m‐cresol and exhibited inherent viscosities from 0.37–0.86 dL/g and glass transition temperatures from 219–289°C. Thermogravimetric analyses showed 5% weight losses from 463–506°C in air and 467–522°C in nitrogen. Unoriented thin films exhibited tensile strengths, moduli, and break elongations at 23°C of 10.2–12.5 ksi, 318–365 ksi, and 4–7%, respectively, and at 177°C of 5.1–6.9 ksi, 256–296 ksi, and 1–5%, respectively. A 50 : 50 random copolymer prepared from 1,3‐bis(4‐fluorobenzoyl) benzene, 1,1'‐(4,4'‐biphenylene)‐bis[2‐(4‐hydroxyphenyl)benzimidazole], and 5,5'‐bis[2‐(4‐hydroxyphenyl)benzimidazole] exhibited higher moisture absorption and lower tensile properties than those predicted by a rule of mixtures relationship. The chemical, physical, and mechanical properties of these polymers are discussed. © 1993 John Wiley & Sons, Inc.‡