Polymer, Vol.40, No.10, 2631-2637, 1999
Influence of orientation and irradiation on stress relaxation of linear low-density polyethylene (LLDPE): a two-process model
Change in the stress relaxation behavior of linear low-density polyethylene (LLDPE) with drawing and irradiation has been investigated. Samples of isotropic LLDPE were oriented to draw ratios lambda = 6,9,11 and irradiated to integral doses between 35 and 500 kGy. Stress relaxation was interpreted in terms of a two-process model, first associated with the crystal and second with the amorphous fraction. Analyses of viscoelastic properties of these two fractions have revealed their different behavior upon drawing and irradiation.
Keywords:MOLECULAR-WEIGHT POLYETHYLENE;MODULUS POLYETHYLENE;MELTINGBEHAVIOR;RADIATION;CREEP;RECOVERY;SOLIDS;DRAWN