SOLUTION AND SOLID-STATE NMR CHARACTERIZATION OF POLY(PARA-PHENYLENE TEREPHTHALAMIDE)

NMR spectroscopy has been used to characterize poly(p-phenylene terephthalamide) in the solid state and in solution in sulfuric acid. Solid-state **1**3C NMR spectra illustrate that the chain structure is highly ordered in the solid state and is of lower symmetry than in solution. Solid-state **1**3C and **1H NMR results show that only very limited motion takes place over the temperature range of minus 170 to plus 200 degree C. High-resolution NMR spectra can be observed only in very dilute isotropic solutions because it is the overall rotational motion of the polymer, not segmental motion, that averages the nuclear spin interactions in their isotropic values.