Crosslink Enhancement in Polypropylene Film by Gamma Irradiation in the Presence of Acetylene

Abstract

The effects of crosslink enhancement by the presence of acetylene during gamma irradiation, on the physical and mechanical properties of polypropylene film are reported. Gel contents show that crosslink enhancement is considerably greater if the sample is highly annealed (PPA) than if it is quenched (PPQ). For PPA, thermal analysis suggests only minor damage to the crystalline lamellae, but significant stabilisation of lamellae by crosslink formation in the lamellar surface regions. This is supported by an increased resistance to the yielding process observed in tensile stress/strain and creep tests. The effects in PPQ is less.