The objective of this research is to study the homogeneity of segmental mixing in polymer blends in which a small number of interacting groups are responsible for miscibility. Although specific interaction has proven to be very effective in promoting miscibility, there are still unresolved questions about the molecular picture of the state of segmental intermixing. Based on preliminary results, diffusional probes to study segment mobility in these blends will be used because the diffusion of a small molecule in polymers involves the cooperative motion of only a small number of segments and provides information about the degree of mixing on a scale smaller than that associated with the glass-transition phenomenon. CP/MAS carbon-13 NMR studies will be carried out in parallel with diffusion experiments. This method offers the advantage in being able to determine the relaxation responses of each component in the blend independently and should provide answers to the disposition of segments of otherwise immiscible polymers brought together by a small number of interacting groups.
