Studies on the Nature of Order in Amorphous Polymers

Abstract

The structure of the melt or glassy state of flexible chain molecules is determined both by the local Positional and orientational distribution of chain segments belonging to the same chain (intramolecular correlation) or belonging to different chain (intermolecular correlations). The statistical treatment of the condensed state or molecular fluids suggests UM the analysis of general singlet and pair distribution functions, containing the angular distribution of the molecular axes, offers a promising way to characterize the structure of amorphous polymers. These functions are obtainable from srnall and wide angle x-ray scattering, electron and neutron scattering, and polarized and depolarized light scattering, as well as from dielectric relaxation and electric birefringence studies. We have used these different techniques in order to determine the singlet and pair distribution functions for a large variety of different polymers. The general conclusion is that the position xl andjorient tiQpAL9rder L_ ____oserved for polymers in the melt and the glassy state agrees well with those found in low molecular weight g~!Wrovided that we consider just flexible chain molecules. There is no structural evidence in these polymers for a liquid-liquid transition.