Postirradiation polymerization of y-irradiated N-tert-butylacrylamide was studied at 80, 85, 90, and 100"C, and the activation energy was found to be 183 kJ . mol-'. By ESR spectroscopy, the half-life for the second order decay of the irradiated monomer was found to be 13,s h at 25 "C with a decay rate constant of 4,5 * lo6 g . mol-' . h-I. The effect of oxygen and sulfur dioxide on y-irradiated N-tert-butylacrylamide was also studied. It was observed that oxygen reacts with N-tert-butylacrylamide free radicals resulting in a characteristic peroxyl radical spectrum. The signal decays rapidly and disappears in about 100 h. The decay was found to be of second order with a rate constant of 1,3 . lo7 g . mol-' * h-' and a half-life of 3,s h a t 25 "C.