It is proposed to purchase a rheometer capable of making steady, transient, and dynamic rheological measurements of polymer solutions. This equipment would support research in liquid crystals, polyelectrolytes, characterization of novel polymers, aggregation phenomena in nitrocellulose and hydrozpropyl lignins, and ionomers used as elastomers. These materials have complex rheological behavior including shear rate- and time-dependent viscosity and elasticity. In order to characterize these microstructures in their unpreturbed state, it is essential to make rheological measurements at very low stress levels. These materials such low viscosities and storage and loss moduli that extremely sensitive torque transducers are needed. Rheological measurements with the proposed equipment serve two purposes. First, one can relate a polymer's microstructure to specific rheological properties, providing guidance on how to alter the molecular structure of a polymer to obtain a desired property. Secondly, one can determine the optimum processing conditions for obtaining desired properties.
