Melt-processable blends were prepared from rigid molecules of an ionically modified poly(p-phenylene terephthalamide) (PPTA) and flexible-coil molecules of poly(4-vinylpyridine) (PVP). Dynamic mechanical analyses of blends with 50% or more of the ionic PPTA component revealed the presence of two distinct phases. The glass-transition temperature of the more stable, ionic PPTA-rich phase increased linearly with the ionic PPTA content. The second phase present in these blends was an ionic PPTA-poor, or a PV-P-rich, phase. For this phase, a reasonably good fit of the data showing the glass-transition temperature as a function of the ionic PPTA content, was achieved between the results of this study and the reported results of previous investigation of molecular composites of the same two components with ionic PPTA contents of 15 wt % or less. The possible influence of annealing on the blend structure of a 90/10 blend of ionic PPTA and PVP was examined. (C) 2003 Wiley Periodicals, Inc.