Ultimate and toughness properties of γ-irradiated EPDM
Résumé
Mechanical properties, especially rupture properties, of unfilled EPDM submitted to different radiation doses (with a dose rate of 1 kGy/h) are presented and discussed. The elastomer structure modifications, via chain scission and crosslinking, lead to a small increase in the strain at break, that can be described by the Kuhn approach, which relates it to the extensibility limit of the elastically active chains of the network. The critical strain energy release rate, G0, evaluated from tests on notched samples can be roughly described by the Lake and Thomas model, if the presence of soluble and dangling chains is taken into account in the calculation of the mean values used in the model equation. G0 is not correlated to the ultimate properties indicating the main influence of the crack initiation step on the material rupture. © 2017 Elsevier Ltd