AbstractThe radical copolymerization of14C‐labelled N‐ethylacrylamide with N‐ethylmethacrylamide, N‐(2‐hydroxypropyl)methacrylamide and N‐butylmethacrylamide in dimethylsulphoxide at 60°C was investigated. The copolymerization of N‐ethylacrylamide with N‐butylmethacrylamide was also studied in dimethylformamide and methanol. The results show that the structure of the alkyl group bonded to the amide nitrogen does not affect the reactivity of the compounds under investigation to any considerable extent. The solvent exhibits a somewhat stronger influence upon the copolymerization parameters. Because of the similar structure of both comonomers the copolymerization parameters will be affected by the solvent only as a result of the different dependence of the reactivity of N‐ethylacrylamide and N‐butylmethacrylamide on the cha