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

The combination of anionic polymerization and controlled chlorosilane chemistry made possible for the first time the synthesis of model 3-miktoarm star terpolymers of styrene (PS), isoprene (PI) and 2-vinylpyridine (P2VP) (3μ-SIV). The morphology of a nearly symmetric 3μ-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 occupies the remaining space forming non-regular curved hexagons, hexagonally packed as well. The star junction points reside on periodically spaced, parallel lines defined by the intersection of the three microdomain interfaces. Non of the phases form the matrix. The star molecular architecture gives the molecule the ability to 'choose' which arms directly interact in the microphase segregate state, in order to minimize the most highly unfavorable contact between the PI and P2VP arms.