Monolayers of graft and block copolymers

Abstract

Abstract Surface pressure-area isotherms for monolayers from graft copolymers with one branch (or four) and diblock copolymers were determined at air/aqueous medium interfaces. The dependence of surface pressure on area for poly(vinyl acetate) (PVAc)-polystyrene(PS) graft and block copolymers was identical to that of pure PVAc at the large areas, while a sharp increase in pressure appeared with further compression. The surface pressure of PVAc-PS graft copolymer at the air/0. 2 N NaOH interface decreased with time, but the critical area at which the surface pressure increased rapidly remained constant, regardless or hydrolysis time. When a poly(vinyl alcohol) (PVA)-PS graft or block copolymer was spread over water, the surface pressure originating from the PVA chain was too small to be observed, and merely that of the PS sequence appeared. It was concluded that the PS sequence was always present in the form of a tightly coiled sphere at the interfaces, whereas the PVAc sequence was spread as a monomolecul...