The influence of segmented block copolymers in immiscible polymer blends

One mechanism for compatibilization of immiscible polymer blends is adding block copolymers (BCP) that consist of segments chemically comparable to the parent homopolymers in the blend. BCP do both, emulsify the disperse phase to give smaller particles as well as increase the interfacial adhesion between the phases. The influence of segmented BCP in blends of immiscible high-performance polymers was investigated systematically by variation of the flexibility of the BCP segments. It was shown that the stiffness of the second segment in polysulfone (PSU) block copolymers as well as the PSU segment molecular weight determine the intermixing between the BCP and the PSU matrix.