Effect of Electron Beam Irradiation, EPDM and Azodicarbonamide on the Foam Properties of LDPE Sheet

The effect of electron beam irradiation, EPDM blending, and Azodicarbonamide (ACA) concentration on the foaming properties of LDPE sheet was investigated. The studied properties are foaming degree, cell densities, mechanical properties and thermal decomposition properties. The data showed that the increasing of foaming agent (ACA) concentration reduces the mechanical properties and increases the gel content. Also, electron beam irradiation has a clear effect on increasing the cell density, mechanical properties gel content and thermal properties of irradiated samples when compared with unirradiated samples. EPDM blending with LDPE at a concentration of 20% reduces the doses required to obtain the foaming degree (71.4%) from 50 kGy in LDPE to 5 kGy in LDPE/EPDM (80/20%). This effect may be attributed to enhancement of radiation cross-linking for LDPE by blending with the amorphous polymer (EPDM).