Effect of gamma irradiation on the stress-relaxation of drawn LLDPE

The stress-relaxation behaviour of undrawn and drawn linear low density polyethylene (LLDPE) samples has been studied as a function of radiation dose over the range 0-500 kGy. It is shown that stress improves progressively with increasing radiation dose for all the samples, but this effect is greatest for undrawn samples. The crystallinity has been studied by wide-angle X-ray diffraction (WAXD). Crystallinity has been found to increase with increasing draw ratio and radiation dose. The stress-relaxation behaviour is discussed in terms of gamma radiation induced effects and increasing crystallinity. (C) 1998 Elsevier Science Limited. All rights reserved