[en] A series of ethylene--carbon monoxide copolymers have been prepared by chemical catalysis and ⁶⁰Co gamma radiation induction, ranging in carbon monoxide content from 41 to 49%. A correlation has been established between the method of preparation, the carbon monoxide content of the copolymers and the mechanical properties of the resulting products. Present evaluations indicate that copolymers containing approx. 50% carbon monoxide prepared by ⁶⁰Co gamma induction have significantly improved mechanical properties over copolymers prepared by conventional chemical free-radical catalysis. Based on these results, it is suggested that further experimentation be conducted in radiation-induced copolymerization especially with the use of electron beam machines presently available to industry