Films of ethylene‐co‐octene copolymer are irradiated in air after moulding between Mylar® films with electron beam at different doses. To correlate the change in structure with properties, the irradiated and unirradiated samples are characterised by FTIR spectroscopy, swelling and mechanical measurements. Obtained changes are dependant on the radiation dose of the incident electron beam. Irradiation induces trans‐vinylene double bonds detected by FTIR spectroscopy in transmission mode. No hydroxyl (OH) and carbonyl (C?O) groups were recorded by FTIR spectroscopy. More drastic changes are observed with swelling method and by mechanical properties showing the crosslinking effect. Based on the results obtained by analytical techniques used in this study, free radicals mechanism involving mainly the pendant chains of the PE‐co‐O is proposed.
