1H, 2H and 13C NMR spectra and molecular dynamics of some solid alkylene‐aromatic polyesters

Abstract

AbstractMolecular dynamics of some mesomorphic main–chain alkylene–aromatic polyesters have been investigated by means of NMR spectra of various nuclei over a wide temperature range. In solid polymers regions of different molecular mobilities coexist and their fractions are determined by the sample temperature and thermal history. The sample annealing leads to the growth of rigid fraction. It was found that below the glass transition temperature the only forms of large–scale mobility are the torsional vibrations and flips of para–phenylene groups, while spacer groups are virtually rigid. Above the glass temperature almost all phenylene rings undergo flipping motions and methylene groups of the spacer take part in complicated motions of both anisotropic and isotropic character.