Interaction strengths in styrene-diene block copolymers and their hydrogenated derivatives

A series of styrenic block copolymers, styrene-isoprene (S/I) and styrene-butadiene (S/B) diblocks and triblocks were employed to examine the effects of saturation on the interblock interaction strength. All block copolymers are of similar composition, allowing for a straightforward comparison between materials of different chemistry. Selective saturation of the diene block increases interaction energy density (X), but the magnitude of the increment in X varies strongly with the chemical structure of polydiene. The large increases in the interaction strength on diene selective hydrogenation are qualitatively captured by group contribution calculations except for those seen on dual hydrogenations.