Synthesis and morphology of model 3-miktoarm star terpolymers of styrene, isoprene and 2-vinyl pyridine

The combination of anionic polymerization and controlled chlorosilane chemi stry made possible for the first time the synthesis of model 3-miktoarm sta r terpolymers of styrene (PS), isoprene (PI) and 2-vinylpyridine (P2VP) (3 mu-SIV). The morphology of a nearly symmetric 3 mu-SIV star terpolymer, was also studied. From the preliminary results, it seems that the PI and P2VP phases form hexagonally packed adjoined cylinders, whereas the PS phase occ upies the remaining space forming nonregular curved hexagons, hexagonally p acked as well. The star junction points reside on periodically spaced, para llel lines defined by the intersection of the three microdomain interfaces. Non of the phases form the matrix. The star molecular architecture gives t he molecule the ability to "choose" which arms directly interact in the mic rophase segregate state, in order to minimize the most highly unfavorable c ontact between the PI and P2VP arms.