Polymer composites containing the rigid poly(p-benzamide) (PEA) and the flexible sulfonated polystyrene (SPS) or poly(vinyl acetate) (PVA) are prepared using a two-step method. The SEM micrographs show that both PBA-SPS and PBA-PVA composites contain particles in the colloidal range, with sizes around 50 nm. The FT-i.r. spectra reveal that there are strong interactions between PEA and SPS; those between PEA and PVA are weaker. Two successive thermal scannings suggested that these colloidal scale dispersions are kinetically rather than thermodynamically stable.