Interaction of nitrous acid with aqua solution of poly(acrylamide) giv
es poly(acrylic acid) in quantitative conversion yields. The reaction
proceeds smoothly, with simultaneous evolution of nitrogen, provided t
hat the temperature below 5 degrees C. The procedure presented provide
s a versatile route to prepare acrylic acid-acrylamide copolymers in a
ny desired composition, by adjusting molar ratio of nitrous acid.