| Abstract: | A further study on mechanical properties and morphology evolution of high density poly (ethylene)/ethylene‐vinyl acetate/and organically‐modified montmorillonite (HDPE/EVA/OMT) nanocomposites exposed to gamma‐rays (0–200 kGy) has been achieved. The results showed that nanocomposites have superior irradiation‐resistant properties to HDPE/EVA blend in mechanical properties. A transmission electron microscope study verified that a face‐face ordered nanostructure had been induced by gamma‐rays. The aim of this paper is to provide a possible mechanism on how the OMT influences the general properties of irradiated nanocomposites, based on the results of thermal, flammability and mechanical behavior. Three facts are postulated to be responsible for the mechanism. The first is the segregation of nano‐dispersed clay layers not only reduces polymer oxidation but prevents crosslinking reactions. The second is the nanostructure evolution induced by gamma‐rays, which may impart nanocomposites improved elasticity. The last is due to the Hofmann degradation, whose degraded products have opposite roles, accelerating polymer oxidation or promoting crosslinking reactions. These facts interact as well as compete with others. The properties of the nanocomposites strongly depended on the prevalent effects developing with increasing irradiation doses. Copyright © 2005 John Wiley & Sons, Ltd. |
