Chemistry and Properties of Poly (Arylene Ether Imidazole)s

Poly(arylene ether imidazole)s were prepared by the aromatic nucleophilic displacement reaction of two new bis(hydroxyimidazole) compounds with activated aromatic dihalides. The bis(hydroxyimidazole) compounds were prepared in high yields from either isophthalaldehyde or terephthalaldehyde, 4-hydroxybenzil and ammonium acetate. The polymers had glass transition temperatures ranging from 245 to 301°C and inherent viscosities from 0.46 to 1.46 dlg -1 . Thermogravimetric analysis indicated a 5% weight loss occurring at about 400°C in air and about 500°C in nitrogen. Thin films tested at room temperature exhibited tensile strengths and moduli from 13.6 to 17.6 ksi and 396 to 464 ksi respectively. The polymers maintained good retention of room temperature strengths and moduli when tested at 177°C. Titanium-to-titanium tensile shear strengths measured at 23 and 177°C were 4000 and 3600 psi respectively. In addition, preliminary data were obtained on carbon fiber laminates. The chemistry, physical and mechanical properties of these polymers are discussed.