9815942 Cooper The solution properties of ionomers as well as associating polymers will be investigated. Viscometric, static and dynamic light scattering, SAXS, SANS, and rheological experiments on multi-functional telechelic and polyurethane ionomers will be used to determine the structure and thermodynamics of ionomer solutions in different polarity solvents and mixed solvents over a broad concentration regime. The study can be expected to provide insight into the controversial origin of polyelectrolyte behavior. The internal structure and dynamics of the ionic aggregates will be modeled using Monte Carlo and molecular dynamics simulations. The effect of deformation on the structure and chain stretching of hydrophobically terminated associating polymers will be determined through rheological, flow birefringence, and SANS studies. Particular attention will be paid to determine the molecular factors governing shear thickening phenomena. The experimental findings will be tested against the theoretical predictions of a molecular model for telechelic associating systems such as random copolymer ionomer solutions. %%% The proposed research plus other projects related to studies of ionomer morphology and block copolymers represent a broad and integrated program designed to bring fundamental understanding of complex fluid rheology. The results of the proposed studies will lead to a more complete understanding of ionomer solution behavior, leading to better utilization in commercial applications. The experimental data will instigate the development of new theories as well as provide a means of testing them. The overall research findings resulting from this investigation should be useful in defining more predictable processing conditions for these important classes of polymers. These materials find applications as membranes, adhesives, coatings, viscosity modifiers, and packaging materials; all of which are sensitive to the material processing history.
