Morphology of amorphous polymers

It has been suggested that amorphous polymers consist of small domains (30 to 100 A) in which there is local ordering or alignment of neighboring segments. Although free volume remains the primary physical parameter useful in characterizing the properties of amorphous polymers (as percent crystallinity for crystalline polymers), the distribution of the free volume, as determined by the size, interconnection, internal order, etc. of the domains is proposed to also be of importance. The paper reviews electron microscope and electron diffraction evidence for the presence of the domain structure, while also pointing out significant remaining problems.