Crystal solvates of thermotropic alkylenearomatic copolyesters and poly(m-phenyleneisophthalamide) with N-methylmorpholine-N-oxide

Abstract

The dissolution of thermotropic alkylenearomatic LC copolyesters and isotropic poly(m-phenyleneisophthalamide) in a high-polarity donor solvent, N-methylmorpholine-N-oxide, has been studied. It has been demonstrated that N-methylmorpholine-N-oxide shows high dissolving power with respect to hydrophobic synthetic polymers. In this case, the dissolution of the polymers is accompanied by the formation of crystal solvates of different compositions. With the use of polarization microscopy, DSC, and X-ray diffraction, the stages of formation of crystal solvates have been examined and the phase equilibrium in systems containing crystal solvates has been investigated. Special attention is given to the structural and morphological features of such heterophase systems.