The microestructure of polyethylene foams produced by a nitrogen solution process

An experimental study on the cellular structure and polymer morphology of a collection of polyethylene foams produced by a nitrogen solution process i s presented in this work. Scanning electron microscopy (SEM) was used to ch aracterise the cellular structure. Raman spectroscopy, wide-angle X-ray dif fraction (WAXD), differential scanning calorimetry (DSC), dynamic mechanica l analysis (DMA) and SEM were utilised to analyse the polymer morphology. T he experimental results showed that the polymer morphology of the solid pha se, which comprises the cell walls of the foams is different to that observ ed in continuous polymers. Moreover, the final polymer morphology of a give n foam depends on the cellular structure of the material. (C) 2001 Elsevier Science Ltd. All rights reserved.