The flow properties, or rheology, of polymer solids and melts are important to the understanding of polymer fabrication processes and the properties of the final polymeric product. Rheology also provides insight into the structure of the material. Rheological properties are measured by rotational, capillary and extensional rheometers, along with other specialized instruments. Current projects include studies of electro-rheological fluids and gels, the behavior of block copolymer solutions, the processing of nanocomposites and electrifying.

Research Interest: Phase Behavior in Polymer Solutions & Blends

Polymer solution properties are extremely important to both the processing of polymeric materials and to the properties of the final product. Although many theories of polymer solutions have been developed and tested for dilute solutions and can be applied to concentrated solutions, many problems remain, especially for solutions of stiff polymers and their hydrodynamic properties. For solutions in which phase separation occurs, theoretical description becomes extremely difficult.

Under this broad heading fall several current research topics. In these, the phase behavior of block copolymer solutions the influcence of electric fields on mixed polymer solutions for membrane applications including proton exchange monomers.

Research Interest: Aging of Polymeric Dielectrics

In any application, knowledge of the failure and degradation of the polymeric material is important. While polymers can initially possess very good properties, often these decay with time and, eventually, failure may occur. Research is aimed at discovering the mechanisms of degradation under electrical, chemical, and radiative stresses. We are particularly concerned with methods for modeling the degradation of materials exposed to several stresses at once, so that reasonable predictions of useful life of a material can be made. While most of the methods developed so far are empirical in nature, they have proven to be useful. We are currently working on methods that can connect physical property degradation with the fundamental, underlying chemical reactions.