The mechanical response of clay-reinforced polyethylene nanocomposite is investigated and the behavior compared with the un-reinforccd polyethylene under identical conditions of processing. The micromechanism of plastic deformation during impact loading of neat polyethylene and cl ay-rei it forced polyethylene nanocomposite are studied with scanning electron microscopy (SEM). The impact strength of composites is linked to structural studies by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and transmission electron microscopy (TEM) and SEM observations. The addition of clay to polyethylene retains adequately high-impact strength in the investigated 0 temperature range of -40 to +70 degrees C. The micromechanism of deformation is altered from a combination of craze and drawing of fibrils in neat polyethylene to microvoid coalescence-fibrillated process in the nanocomposite. The aspects related to micromechanism of deformation are discussed. (c) 2006 Elsevier Ltd. All rights reserved.