Miscibility Enhancement Via Ionic Interactions in the Phenylated Polyphenylene Oxide/Poly (Ethyl Acrylate) Blend System

Blends of sulfonated phenylated polyphenylene oxides with ethyl acrylate-4-vinyl pyridine copolymers were prepared by solution blending. Dynamic mechanical measurements were used primarily to study miscibility. A blend of unfunctionalized phenylated polyphenylene oxide with pure poly (ethyl acrylate) is immiscible, as seen from a two-step descent in the storage modulus curve and the presence of two loss tangent peaks. A dramatic improvement in miscibility is seen from the presence of a single but broad descent in the storage modulus curve for stoichiometric blends of functionalized polymer mixtures of equivalent weight ≤ 600. While the breadth of the drop in the storage modulus curve with temperature suggests that the mixture is heterogeneous, the absence of two well defined steps in the storage modulus curve indicates that these blends exhibit the effects of strong interactions. Proton transfer from the sulfonic acid to the 4-vinyl pyridine ring has been confirmed by infrared study.