PREPARATION AND PROPERTIES OF HIGH MOLECULAR WEIGHT, SOLUBLE OXOBENZ[DE]IMIDAZOBENZIMIDAZOISOQUINOLINE LADDER POLYMER

The synthesis of double chain or ladder polymers from 1,2,4,5-tetraaminobenzene and 1,4,5,8-naphthalenetetracarboxylic acid has been optimized. High ladder polymers of high quality were obtained from the free tetraamine, as well as its hydrochloride salt, in polyphosphoric acid polycondensations at 180°. These ladder polymers were completely soluble in methanesulfonic acid and had intrinsic viscosities ranging from 1 to 6 dl/g. Film-forming and fiber-forming properties were demonstrated. TGA weight losses of less than 10% at 600° in air and less than 5% at 700° in nitrogen were observed. Low-viscosity ladder polymers were obtained from polycondensations in methanesulfonic acid. © 1969, American Chemical Society. All rights reserved.