Compatibilizing effect of block copolymers added to the polymer/polymer interface

The compatibilizing effect of block copolymer addition on the interfacial tension between two immiscible homopolymers is studied as a function of the concentration of the additive for the ternary system polystyrene/1,2-polybutadiene/poly(styrene-block-1,2 butadiene). A sharp decrease in interfacial tension is observed with the addition of small amounts of copolymer, followed by a leveling off as the copolymer concentration is increased above the apparent critical micelle concentration (CMC). For concentrations below this critical concentration, the interfacial tension reduction is essentially linear in the copolymer content and compares well with the predictions of Noolandi and Hong. 61 ref.--AA