Isothermal crystallization of gamma irradiated LDPE in the presence of oxygen

• Isothermal crystallization of irradiated LDPE in different atmospheres was studied.
• At a given radiation dose, induction time is higher the lower is oxygen content present in the radiation process.
• The Ea for crystallization increases with the radiation dose and decreases with oxygen content.
• TTT diagrams reflected the effects of the doses and the oxygen content.

This work is focused on the study of the effect of oxygen on the isothermal crystallization process of gamma irradiated low density polyethylene (LDPE). The induction time increased with the dose indicating a retarding effect. On other hand, at the same dose, this parameter decreased with the augment in the oxygen content. The classical Avrami equation was used to analyze the crystallization kinetic of these materials. n values suggested that both, the dose and the oxygen content, did not affect the mechanism of crystals growth. An Arrhenius type equation was used for the rate constant (k). Used models correctly reproduced the experimental data. TTT diagrams of studied materials were constructed and also reflected the effects of the doses and the oxygen content.