Thermally stable sulfone-containing poly(amide-imides)

Novel sulfone containing poly(amide-imides) have been prepared by reacting 3,4-dicarboxy-4′-(chloroformyl)-diphenylsulfone dianhydride with various aromatic diamines. Relatively high molecular weight polymers were obtained by using a two-step procedure. Transparent poly(amide-imide) films, varying in color from dark yellow to colorless, were formed by thermally treating polyamic acid solutions. All films showed good thermal stability.