Structure and Dynamics of Polymer Mixtures

9528481 Lodge Polymer mixtures - blends, copolymers, and combinations thereof - are an increasingly important source of superior macromolecular materials. Four specific project areas are identified. The first concerns the underlying timescale for segmental rearrangements, which impacts all dynamic properties through the monomeric friction factor. A second project will examine tracer diffusion in weakly-segregated copolymers and blends. The third thrust emphasizes more strongly-segregated structures, namely block copolymers in the ordered state, and the tracer diffusion of copolymers, homopolymers, and small molecule probes therein. The final area of interest is the role of solvent concentration and quality in determining the morphologies adopted by block copolymers. Particular emphasis will be placed on continuously-variable solvent selectivity, to be achieved in part via mixed solvent. %%% This research will lead to fundamental understanding of structures and interactions of polymer chains in mixtures of polymers and copolymers with extensions on processability and property optimization. ***