This award will support collaborative research between Dr. Jeffrey Koberstein, Institute of Materials Science, University of Connecticut and Dr. Yves Gallot, Institute Charles Sadron, Strasbourg, France. The objective of the project is to investigate the interfacial activity of block copolymers added to immiscible polymer blends. The modification of polymer-polymer interfaces is a problem of great current industrial and academic interest. This interest is due in large part to the recent recognition of the importance of polymer interphase behavior to a broad spectrum of technologies including rubber toughening, dispersion stability, polymer blends, adhesion, and multiplier films. Many of these technologies employ block copolymers to accomplish this modification. At present, however, there is little basis for the design or optimization of interfacial agents for specific applications. The objective of the proposed research is to provide such a basis by carrying out a systematic study of the effects of block copolymer composition, content, and architecture on their efficacy as interfacial agents for immiscible homopolymer blends. The success of this proposition is contingent upon the ability to synthesize well characterized block copolymers, to quantita- tively ascertain their interfacial activity, and to compare these results with thermodynamic theories of interfacial properties. The project will benefit from the complementary expertise of the US and French groups. The French team has extensive experience in the anionic synthesis of well- characterized block copolymers, as well as in their structure- property relationships. The U.S. team brings expertise in the structural characterization of block copolymers by scattering techniques, and in the measurement of polymer-polymer interfacial tension. The latter technique has already proven successful for the study of interfacial activity of block copolymers. When coupled with the specimens prepared by the French team, these experiments will provide a basis of fundamental knowledge pertaining to interfacial activity of block copolymers and its relationship to molecular architec- ture.
