AbstractThe rate of the radiation‐initiated polymerization of ethenesulfonamide, which is relatively high (1.25%/min.), is dependent on the 0.96 power of the intensity of the radiation. At increasing radiation dose levels the viscosity decreases and then remains constant indicating a balance between radiation‐induced degradation and branching. The polyelectrolyte character of the polymer is shown in both viscosity and light‐scattering