Synthesis of poly(aryl ether-phenylquinoxalines)

Abstract

Poly(phenylquinoxaline) (PPQ, 1) and related structures comprise a class of high-temperature polymers exhibiting many desirable characteristics including excellent thermo-oxidative stability, high glass transition temperature (Tg) and modulus, and low dielectric constant.1 In addition, PPQ is soluble in selected organic solvents (e.g., chloroform and m-cresol) in a fully cyclized form, preceding the need for high-temperature curing reactions. PPQ is generally synthesized through the condensation of an aromatic bis(o-diamine) with a bis(phenyl-α-dicarbonyl) compound.2,3 Both homopolymers and statistically random copolymers have been prepared with glass transition temperatures ranging from 284 to 420 °C, depending on the monomers used in the synthesis. Structures with lower Tgs generally contain ether linkages introduced through the bis(dicarbonyl) monomer.4 High elongations and tough ductile mechanical properties are typical characteristics of these materials. Furthermore, it has generally been recognized that aromatic ether linkages in the polymer backbone provide improved solubility and processibility as well as a lower Tg.5. © 1988, American Chemical Society. All rights reserved.