Abstract
The microphase separation of the new miktoarm styrene-diene polymers has been examined. At the molecular weights studied, the PS arms always separate from the polydienes, but the PI and PB arms mix when they occur in the same molecule. The miktoarm architecture does seem to strongly affect the kind of microphase separated domain that is formed in these polymers. The polymers with a single PS arm and two polydiene arms formed PS cylinders, whereas a lamellar or bicontinuous structure would have been found for linear block polymers. This appears to be due to effects of the miktoarm structure on the curvature energy of the interface.